Classification tree and minimum-volume ellipsoid analyses of the distribution of ponderosa pine in the western USA

USGS Publications Warehouse

Norris, Jodi R.; Jackson, Stephen T.; Betancourt, Julio L.

2006-01-01

Aim? Ponderosa pine (Pinus ponderosa Douglas ex Lawson & C. Lawson) is an economically and ecologically important conifer that has a wide geographic range in the western USA, but is mostly absent from the geographic centre of its distribution - the Great Basin and adjoining mountain ranges. Much of its modern range was achieved by migration of geographically distinct Sierra Nevada (P. ponderosa var. ponderosa) and Rocky Mountain (P. ponderosa var. scopulorum) varieties in the last 10,000 years. Previous research has confirmed genetic differences between the two varieties, and measurable genetic exchange occurs where their ranges now overlap in western Montana. A variety of approaches in bioclimatic modelling is required to explore the ecological differences between these varieties and their implications for historical biogeography and impending changes in western landscapes. Location? Western USA. Methods? We used a classification tree analysis and a minimum-volume ellipsoid as models to explain the broad patterns of distribution of ponderosa pine in modern environments using climatic and edaphic variables. Most biogeographical modelling assumes that the target group represents a single, ecologically uniform taxonomic population. Classification tree analysis does not require this assumption because it allows the creation of pathways that predict multiple positive and negative outcomes. Thus, classification tree analysis can be used to test the ecological uniformity of the species. In addition, a multidimensional ellipsoid was constructed to describe the niche of each variety of ponderosa pine, and distances from the niche were calculated and mapped on a 4-km grid for each ecological variable. Results? The resulting classification tree identified three dominant pathways predicting ponderosa pine presence. Two of these three pathways correspond roughly to the distribution of var. ponderosa, and the third pathway generally corresponds to the distribution of var. scopulorum. The classification tree and minimum-volume ellipsoid model show that both varieties have very similar temperature limitations, although var. ponderosa is more limited by the temperature extremes of the continental interior. The precipitation limitations of the two varieties are seasonally different, with var. ponderosa requiring significant winter moisture and var. scopulorum requiring significant summer moisture. Great Basin mountain ranges are too cold at higher elevations to support either variety of ponderosa pine, and at lower elevations are too dry in summer for var. scopulorum and too dry in winter for var. ponderosa. Main conclusions? The classification tree analysis indicates that var. ponderosa is ecologically as well as genetically distinct from var. scopulorum. Ecological differences may maintain genetic separation in spite of a limited zone of introgression between the two varieties in western Montana. Two hypotheses about past and future movements of ponderosa pine emerge from our analyses. The first hypothesis is that, during the last glacial period, colder and/or drier summers truncated most of the range of var. scopulorum in the central Rockies, but had less dramatic effects on the more maritime and winter-wet distribution of var. ponderosa. The second hypothesis is that, all other factors held constant, increasing summer temperatures in the future should produce changes in the distribution of var. scopulorum that are likely to involve range expansions in the central Rockies with the warming of mountain ranges currently too cold but sufficiently wet in summer for var. scopulorum. Finally, our results underscore the growing need to focus on genotypes in biogeographical modelling and ecological forecasting.

[Geographic patterns and ecological factors correlates of snake species richness in China].

PubMed

Cai, Bo; Huang, Yong; Chen, Yue-Ying; Hu, Jun-Hua; Guo, Xian-Guang; Wang, Yue-Zhao

2012-08-01

Understanding large-scale geographic patterns of species richness as well its underlying mechanisms are among the most significant objectives of macroecology and biogeography. The ecological hypothesis is one of the most accepted explanations of this mechanism. Here, we studied the geographic patterns of snakes and investigated the relationships between species richness and ecological factors in China at a spatial resolution of 100 km×100 km. We obtained the eigenvector-based spatial filters by Principal Coordinates Neighbor Matrices, and then analyzed ecological factors by multiple regression analysis. The results indicated several things: (1) species richness of snakes showed multi-peak patterns along both the latitudinal and longitudinal gradient. The areas of highest richness of snake are tropics and subtropical areas of Oriental realm in China while the areas of lowest richness are Qinghai-Tibet Plateau, the grasslands and deserts in northern China, Yangtze-Huai Plain, Two-lake Plain, and the Poyang-lake Plain; (2) results of multiple regression analysis explained a total of 56.5% variance in snake richness. Among ecological factors used to explore the species richness patterns, we found the best factors were the normalized difference vegetation index, precipitation in the coldest quarter and temperature annual range ; (3) our results indicated that the model based on the significant variables that (P<0.05) uses a combination of precipitation of coldest quarter, normalized difference vegetation index and temperature annual range is the most parsimonious model for explaining the mechanism of snake richness in China. This finding demonstrates that different ecological factors work together to affect the geographic distribution of snakes in China. Studying the mechanisms that underlie these geographic patterns are complex, so we must carefully consider the choice of impact-factors and the influence of human activities.

An integrated remote sensing approach for identifying ecological range sites. [parker mountain

NASA Technical Reports Server (NTRS)

Jaynes, R. A.

1983-01-01

A model approach for identifying ecological range sites was applied to high elevation sagebrush-dominated rangelands on Parker Mountain, in south-central Utah. The approach utilizes map information derived from both high altitude color infrared photography and LANDSAT digital data, integrated with soils, geological, and precipitation maps. Identification of the ecological range site for a given area requires an evaluation of all relevant environmental factors which combine to give that site the potential to produce characteristic types and amounts of vegetation. A table is presented which allows the user to determine ecological range site based upon an integrated use of the maps which were prepared. The advantages of identifying ecological range sites through an integrated photo interpretation/LANDSAT analysis are discussed.

Range bagging: a new method for ecological niche modelling from presence-only data

PubMed Central

Drake, John M.

2015-01-01

The ecological niche is the set of environments in which a population of a species can persist without introduction of individuals from other locations. A good mathematical or computational representation of the niche is a prerequisite to addressing many questions in ecology, biogeography, evolutionary biology and conservation. A particularly challenging question for ecological niche modelling is the problem of presence-only modelling. That is, can an ecological niche be identified from records drawn only from the set of niche environments without records from non-niche environments for comparison? Here, I introduce a new method for ecological niche modelling from presence-only data called range bagging. Range bagging draws on the concept of a species' environmental range, but was inspired by the empirical performance of ensemble learning algorithms in other areas of ecological research. This paper extends the concept of environmental range to multiple dimensions and shows that range bagging is computationally feasible even when the number of environmental dimensions is large. The target of the range bagging base learner is an environmental tolerance of the species in a projection of its niche and is therefore an ecologically interpretable property of a species' biological requirements. The computational complexity of range bagging is linear in the number of examples, which compares favourably with the main alternative, Qhull. In conclusion, range bagging appears to be a reasonable choice for niche modelling in applications in which a presence-only method is desired and may provide a solution to problems in other disciplines where one-class classification is required, such as outlier detection and concept learning. PMID:25948612

Range bagging: a new method for ecological niche modelling from presence-only data.

PubMed

Drake, John M

2015-06-06

The ecological niche is the set of environments in which a population of a species can persist without introduction of individuals from other locations. A good mathematical or computational representation of the niche is a prerequisite to addressing many questions in ecology, biogeography, evolutionary biology and conservation. A particularly challenging question for ecological niche modelling is the problem of presence-only modelling. That is, can an ecological niche be identified from records drawn only from the set of niche environments without records from non-niche environments for comparison? Here, I introduce a new method for ecological niche modelling from presence-only data called range bagging. Range bagging draws on the concept of a species' environmental range, but was inspired by the empirical performance of ensemble learning algorithms in other areas of ecological research. This paper extends the concept of environmental range to multiple dimensions and shows that range bagging is computationally feasible even when the number of environmental dimensions is large. The target of the range bagging base learner is an environmental tolerance of the species in a projection of its niche and is therefore an ecologically interpretable property of a species' biological requirements. The computational complexity of range bagging is linear in the number of examples, which compares favourably with the main alternative, Qhull. In conclusion, range bagging appears to be a reasonable choice for niche modelling in applications in which a presence-only method is desired and may provide a solution to problems in other disciplines where one-class classification is required, such as outlier detection and concept learning.

Potential bioavailability assessment, source apportionment and ecological risk of heavy metals in the sediment of Brisbane River estuary, Australia.

PubMed

Duodu, Godfred Odame; Goonetilleke, Ashantha; Ayoko, Godwin A

2017-04-15

A weak acid extraction was used to mobilize the loosely bound metals in estuary sediment samples. More than 30% of Ag, As, Ca, Cd, Co, Cu, Hg, Mn Ni, Pb and Zn were leached from the sediment showing that these metals are significantly present in the bioavailable form. PCA/APCS identified three sources of the metals, namely: lithogenic accounting for 72%, shipping related contributing 15% and traffic related representing 13% of the total load. Application of pollution index (PI) and modified pollution index (MPI) revealed that the sediment range from unpolluted to heavily polluted while ecological risk index (RI) classifies the sediment as posing low ecological risk modified ecological risk index (MRI) suggests considerable to very high ecological risk. To provide holistic insights into the ecological risks posed by metals, enrichment factor, MPI and MRI are recommended for the assessment of sediment in complex environments such as estuaries. Copyright © 2017 Elsevier Ltd. All rights reserved.

Insights from ecological niche modeling on the taxonomic distinction and niche differentiation between the black-spotted and red-spotted tokay geckoes (Gekko gecko).

PubMed

Zhang, Yueyun; Chen, Chongtao; Li, Li; Zhao, Chengjian; Chen, Weicai; Huang, Yong

2014-09-01

The black-spotted tokay and the red-spotted tokay are morphologically distinct and have largely allopatric distributions. The black-spotted tokay is characterized by a small body size and dark skin with sundry spots, while the red-spotted tokay has a relatively large body size and red spots. Based on morphological, karyotypic, genetic, and distribution differences, recent studies suggested their species status; however, their classifications remain controversial, and additional data such as ecological niches are necessary to establish firm hypotheses regarding their taxonomic status. We reconstructed their ecological niches models using climatic and geographic data. We then performed niche similarity tests (niche identity and background tests) and point-based analyses to explore whether ecological differentiation has occurred, and whether such differences are sufficient to explain the maintenance of their separate segments of environmental ranges. We found that both niche models of the black- and the red-spotted tokay had a good fit and a robust performance, as indicated by the high area under the curve (AUC) values ("black" = 0.982, SD = ± 0.002, "red" = 0.966 ± 0.02). Significant ecological differentiation across the entire geographic range was found, indicating that the involvement of ecological differentiation is important for species differentiation. Divergence along the environmental axes is highly associated with climatic conditions, with isothermality being important for the "black" form, while temperature seasonality, precipitation of warmest quarter, and annual temperature range together being important for the "red" form. These factors are likely important factors in niche differentiation between the two forms, which result in morphological replacement. Overall, beside morphological and genetic differentiation information, our results contribute to additional insights into taxonomic distinction and niche differentiation between the black- and the red-spotted tokay.

Ecological consistency across space: a synthesis of the ecological aspects of Dromiciops gliroides in Argentina and Chile.

PubMed

Fontúrbel, Francisco E; Franco, Marcela; Rodríguez-Cabal, Mariano A; Rivarola, M Daniela; Amico, Guillermo C

2012-11-01

Dromiciops gliroides is an arboreal marsupial found in the temperate forests of South America (36-43 °S). This species is the sole extant representative of the order Microbiotheria, and is a key seed disperser of many native plant species, including the keystone mistletoe Tristerix corymbosus. Here, we synthesized the current knowledge on the ecological aspects of this species, and compared the available information from Argentina and Chile. Population density (23 ± 2 (mean ± SE) individual/ha) and home range (1.6 ± 0.6 ha) appear to be relatively similar across a marked ecological gradient in the mainland, but lower densities (7 ± 2 individual/ha) and smaller home ranges (0.26 ± 0.04 ha) were detected at island sites. We detected regional variation in body condition in Chile, but there were no significant differences across a wider E-W gradient. Movement patterns fit a random walk model; such behavior might have important consequences in shaping plant's spatial patterns. Although our data suggest that D. gliroides is more tolerant to habitat disturbance than previously thought, its incapability to disperse across non-forested areas suggests that the rapid rate of habitat loss and fragmentation that characterizes southern temperate forests likely poses a serious threat to this species. These ecological similarities are surprising given that forests studied receive dramatically different rainfall and correspond to distinct forest types. The evidence synthetized here dispels some of the myths about this species but also stresses the need for more comprehensive ecological studies across its distribution range.

Diving behavior and movements of juvenile hawksbill turtles Eretmochelys imbricata on a Caribbean coral reef

NASA Astrophysics Data System (ADS)

Blumenthal, J. M.; Austin, T. J.; Bothwell, J. B.; Broderick, A. C.; Ebanks-Petrie, G.; Olynik, J. R.; Orr, M. F.; Solomon, J. L.; Witt, M. J.; Godley, B. J.

2009-03-01

As historically abundant spongivores, hawksbill turtles Eretmochelys imbricata likely played a key ecological role on coral reefs. However, coral reefs are now experiencing global declines and many hawksbill populations are critically reduced. For endangered species, tracking movement has been recognized as fundamental to management. Since movements in marine vertebrates encompass three dimensions, evaluation of diving behavior and range is required to characterize marine turtle habitat. In this study, habitat use of hawksbill turtles on a Caribbean coral reef was elucidated by quantifying diel depth utilization and movements in relation to the boundaries of marine protected areas. Time depth recorders (TDRs) and ultrasonic tags were deployed on 21 Cayman Islands hawksbills, ranging in size from 26.4 to 58.4 cm straight carapace length. Study animals displayed pronounced diel patterns of diurnal activity and nocturnal resting, where diurnal dives were significantly shorter, deeper, and more active. Mean diurnal dive depth (±SD) was 8 ± 5 m, range 2-20 m, mean nocturnal dive depth was 5 ± 5 m, range 1-14 m, and maximum diurnal dive depth was 43 ± 27 m, range 7-91 m. Larger individuals performed significantly longer dives. Body mass was significantly correlated with mean dive depth for nocturnal but not diurnal dives. However, maximum diurnal dive depth was significantly correlated with body mass, suggesting partitioning of vertical habitat by size. Thus, variable dive capacity may reduce intraspecific competition and provide resistance to degradation in shallow habitats. Larger hawksbills may also represent important predators on deep reefs, creating a broad ecological footprint over a range of depths.

Adaptive significance of the Indian caste system: an ecological perspective.

PubMed

Gadgil, M; Malhotra, K C

1983-01-01

Indian society is an agglomeration of several thousand endogamous groups or castes each with a restricted geographical range and a hereditarily determined mode of subsistence. These reproductively isolated castes may be compared to biological species, and the society thought of as a biological community with each caste having its specific ecological niche. In this paper we examine the ecological-niche relationships of castes which are directly dependent on natural resources. Evidence is presented to show that castes living together in the same region had so organized their pattern of resource use as to avoid excessive intercaste competition for limiting resources. Furthermore, territorial division of the total range of the caste regulated intra-caste competition. Hence, a particular plant or animal resource in a given locality was used almost exclusively by a given lineage within a caste generation after generation. This favoured the cultural evolution of traditions ensuring sustainable use of natural resources. This must have contributed significantly to the stability of Indian caste society over several thousand years. The collapse of the base of natural resources and increasing monetarization of the economy has, however, destroyed the earlier complementarity between the different castes and led to increasing conflicts between them in recent years.

Chasing Salmonella Typhimurium in free range egg production system.

PubMed

Chousalkar, Kapil; Gole, Vaibhav; Caraguel, Charles; Rault, Jean-Loup

2016-08-30

Free range production systems are becoming a major source of egg production in Australia and worldwide. This study investigated shedding and ecology of Salmonella Typhimurium and Salmonella species in a free range layer flock, wild birds and foxes in the vicinity of the free range farm in different seasons. Shedding of Salmonella was significantly higher in summer. Within the shed, overall, Salmonella prevalence was highest in dust. Corticosterone level in faeces was highest in spring and lowest in winter. There was no direct association between the Salmonella shedding (MPN/gm) and corticosterone levels in faeces. Salmonella Typhimurium MLVA types isolated from fox and wild birds were similar to MLVA types isolated from layer flock and reported during human food borne illness. Wild birds and foxes appear to play an important role in S. Typhimurium ecology and food safety. Environmental factors could play a role in evolution of S. Typhimurium in free range environment. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

[Contamination and Ecological Risk Assessment of Mercury in Hengshuihu Wetland, Hebei Province].

PubMed

Wang, Nai-shan; Zhang, Man-yin; Cui, Li-juan; Ma, Mu-yuan; Yan, Liang; Mu, Yong-lin; Qin, Peng

2016-05-15

Investigation on the concentrations and the distribution characteristics of total mercury in atmosphere, water surface and soil/ sediments of Hengshuihu wetland was carried out based on a uniform set point sampling method. The geoaccumulation index and potential ecological risk index methods were simultaneously used to assess the mercury pollution in Hengshuihu wetland ecosystem. The results showed that: the total mercury content in Hengshuihu wetland atmosphere ranged from 1.0 to 5.0 ng · m⁻³, with an average of (2.9 ± 0.85) ng · m⁻³; the total mercury content in water surface ranged from 0.010 to 0.57 µg · L⁻¹, with the average value of (0.081 ± 0.053) µg · L⁻¹; the total mercury content in soil/sediment ranged from 0.001 0 to 0.058 mg · kg⁻¹, with an average of (0.027 ± 0.013) mg · kg⁻¹. The distribution features of total mercury in Hengshuihu wetland were as follows: the total mercury concentration in surface water of the shore was significantly higher than that in the center (P < 0.05), but the total mercury concentration of sediments in the center of the lake was significantly higher than that at the shore (P < 0.05); the total mercury in the soil of shore had a consistent trend with that in the atmosphere; high concentrations of total mercury pollution were accompanied by severe human activities. The geoaccumulation index showed that mercury pollution in Hengshuihu wetland was at clean level; potential ecological risk index showed mercury contamination had a low ecological risk in Hengshuihu wetland.

Novel Concordance Between Geographic, Environmental, and Genetic Structure in the Ecological Generalist Prickly Sculpin (Cottus asper) in California.

PubMed

Baumsteiger, Jason; Kinziger, Andrew P; Aguilar, Andres

2016-11-01

Ecological generalists may contain a wealth of information concerning diversity, ecology, and geographic connectivity throughout their range. We explored these ideas in prickly sculpin (Cottus asper), a small generalist freshwater fish species where coastal forms have potentially undergone radiations into inland lacustrine and riverine environments. Using a 962bp cytochrome b mtDNA marker and 11 microsatellites, we estimated diversity, divergence times, gene flow, and structure among populations at 43 locations throughout California. We then incorporated genetic and GIS data into ecological niche models to assess ecological conditions within identified groups. Though not reciprocally monophyletic, unique mtDNA haplotypes, microsatellite clustering, and measures of isolation by distance (Coastal: r = 0.960, P < 0.001; Inland: r = 0.277, P = 0.148) suggest 2 novel taxonomic groups, Coastal and Inland (constrained to Great Central Valley). Divergence estimates of 41-191 kya combined with the regional biogeographic history suggest geographic barriers are absent between groups since divergence, but ecological niche modeling revealed significant environmental differences (t = 10.84, P < 0.001). Introgressed individuals were also discovered between groups in an ecologically and geographically intermediate region. Population structure was limited, predominately found in tributaries of the San Joaquin basin in the Inland group. Overall, C. asper exhibited substantial genetic diversity, despite its ecological generality, reflecting California's historically unique and complex hydrology. More broadly, this study illustrates variable environments within the range of a generalist species may mask genetic divergences and should not be overlooked in biodiversity assessments. © The American Genetic Association 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Marine reserves: fish life history and ecological traits matter.

PubMed

Claudet, J; Osenberg, C W; Domenici, P; Badalamenti, F; Milazzo, M; Falcón, J M; Bertocci, I; Benedetti-Cecchi, L; García-Charton, J A; Goñi, R; Borg, J A; Forcada, A; De Lucia, G A; Perez-Ruzafa, A; Afonso, P; Brito, A; Guala, I; Le Diréach, L; Sanchez-Jerez, P; Somerfield, P J; Planes, S

2010-04-01

Marine reserves are assumed to protect a wide range of species from deleterious effects stemming from exploitation. However, some species, due to their ecological characteristics, may not respond positively to protection. Very little is known about the effects of life history and ecological traits (e.g., mobility, growth, and habitat) on responses of fish species to marine reserves. Using 40 data sets from 12 European marine reserves, we show that there is significant variation in the response of different species of fish to protection and that this heterogeneity can be explained, in part, by differences in their traits. Densities of targeted size-classes of commercial species were greater in protected than unprotected areas. This effect of protection increased as the maximum body size of the targeted species increased, and it was greater for species that were not obligate schoolers. However, contrary to previous theoretical findings, even mobile species with wide home ranges benefited from protection: the effect of protection was at least as strong for mobile species as it was for sedentary ones. Noncommercial bycatch and unexploited species rarely responded to protection, and when they did (in the case of unexploited bentho-pelagic species), they exhibited the opposite response: their densities were lower inside reserves. The use of marine reserves for marine conservation and fisheries management implies that they should ensure protection for a wide range of species with different life-history and ecological traits. Our results suggest this is not the case, and instead that effects vary with economic value, body size, habitat, depth range, and schooling behavior.

[Effects of rare earth elements on soil fauna community structure and their ecotoxicity to Holotrichia parallela].

PubMed

Li, Guiting; Jiang, Junqi; Chen, Jie; Zou, Yunding; Zhang, Xincai

2006-01-01

By the method of OECD filter paper contact, this paper studied the effects of applied rare earth elements on soil fauna community structure and their ecological toxicity to Holotrichia parallela in bean field. The results showed that there were no significant differences between the treatments and the control in soil fauna species, quantity of main species, and diversity index. Urgent and chronic toxic test showed that the differences between the treatments and the control were not significant. It was suggested that within the range of test dosages, rare earth elements had little ecological toxicity to Holotrichia parallela, and did not change the soil fauna community structure.

Integrating Landscape Ecology into Natural Resource Management - Series: Cambridge Studies in Landscape Ecology

NASA Astrophysics Data System (ADS)

Jianguo Liu, Edited By; Taylor, William W.

2002-08-01

The rapidly increasing global population has dramatically increased the demands for natural resources and has caused significant changes in quantity and quality of natural resources. To achieve sustainable resource management, it is essential to obtain insightful guidance from emerging disciplines such as landscape ecology. This text addresses the links between landscape ecology and natural resource management. These links are discussed in the context of various landscape types, a diverse set of resources and a wide range of management issues. A large number of landscape ecology concepts, principles and methods are introduced. Critical reviews of past management practices and a number of case studies are presented. This text provides many guidelines for managing natural resources from a landscape perspective and offers useful suggestions for landscape ecologists to carry out research relevant to natural resource management. In addition, it will be an ideal supplemental text for graduate and advanced undergraduate ecology courses. Written, and rigorously reviewed, by many of the world's leading landscape ecologists and natural resource managers Contains numerous case studies and insightful guidelines for landscape ecologists and natural resource managers

Driving Forces of Dynamic Changes in Soil Erosion in the Dahei Mountain Ecological Restoration Area of Northern China Based on GIS and RS

PubMed Central

Li, Xiao; Niu, Xiang; Wang, Bing; Gao, Peng; Liu, Yu

2016-01-01

Dynamic change in soil erosion is an important focus of regional ecological restoration research. Here, the dynamic changes of soil erosion and its driving forces in the Dahei Mountain ecological restoration area of northern China were analyzed by LANDSAT TM remote sensing captured via geographic information system (GIS) technologies during three typical periods in 2004, 2008 and 2013. The results showed the following: (1) a decrease in intensive erosion and moderate erosion areas, as well as an increase in light erosion areas, was observed during two periods: one from 2004 to 2008 and the other from 2008 to 2013. (2) Between 2004 and 2008, the variation in the range of slight erosion was the largest (24.28%), followed by light erosion and intensive erosion; between 2008 and 2013, the variation in the range of intensive erosion area was the largest (9.89%), followed by slight erosion and moderate erosion. (3) Socioeconomic impact, accompanied by natural environmental factors, was the main driving force underlying the change in soil erosion within the ecological restoration area. In particular, the socioeconomic factors of per capita forest area and land reclamation rate, as well as the natural environmental factor of terrain slope, significantly influenced soil erosion changes within the ecological restoration area. PMID:26981637

Landscape ecology in North America: past, present, and future

Treesearch

Monica G. Turner

2005-01-01

Landscape ecology offers a spatially explicit perspective on the relationships between ecological patterns and processes that can be applied across a range of scales. Concepts derived from landscape ecology now permeate ecological research across most levels of ecological organization and many scales. Landscape ecology developed rapidly after ideas that originated in...

Range Management and Ecology. Curriculum Guide for Agriscience 382.

ERIC Educational Resources Information Center

Texas A and M Univ., College Station. Dept. of Agricultural Education.

This curriculum guide provides materials for teachers to use in developing a course in "Range Management and Ecology, Agriscience 382," one of 28 semester courses in agricultural science and technology for Texas high schools. This introductory course is designed to acquaint students with the ecology and management of native rangeland for…

Antibiotic contamination in a typical developing city in south China: occurrence and ecological risks in the Yongjiang River impacted by tributary discharge and anthropogenic activities.

PubMed

Xue, Baoming; Zhang, Ruijie; Wang, Yinghui; Liu, Xiang; Li, Jun; Zhang, Gan

2013-06-01

The occurrence and distribution of ten selected antibiotics from three groups (sulfonamides, macrolides, and trimethoprim) were investigated in the Yongjiang River, which flows through Nanning City, a typical developing city in China. The study also assessed the ecological risks and the potential effects caused by discharge from tributaries and anthropogenic activities. Concentrations of most of the antibiotics were elevated along the section of the river in the urban area, highlighting the significant impact of high population density and human activities on the presence of antibiotics in the environment. The concentrations in the tributaries (ranged from not detected to 1336ngL(-1)) were generally higher than those in the main stream (ranged from not detected to 78.8ngL(-1)), but both areas contained the same predominant antibiotics, revealing the importance of tributary discharge as a source of antibiotic pollution. A risk assessment for the surface water contamination revealed that sulfamethoxazole and erythromycin posed high ecological risks to the most sensitive aquatic organisms (Synechococcus leopoliensis and Pseudokirchneriella subcapitata, respectively) in the midstream and some tributaries. Most of the selected antibiotics presented high ecological risks (risk quotients up to 95) in the sediments. Copyright © 2013 Elsevier Inc. All rights reserved.

Temporally increasing spatial synchrony of North American temperature and bird populations

NASA Astrophysics Data System (ADS)

Koenig, Walter D.; Liebhold, Andrew M.

2016-06-01

The ecological impacts of modern global climate change are detectable in a wide variety of phenomena, ranging from shifts in species ranges to changes in community composition and human disease dynamics. So far, however, little attention has been given to temporal changes in spatial synchrony--the coincident change in abundance or value across the landscape--despite the importance of environmental synchrony as a driver of population trends and the central role of environmental variability in population rescue and extinction. Here we demonstrate that across North America, spatial synchrony of a significant proportion of 49 widespread North American wintering bird species has increased over the past 50 years--the period encompassing particularly intense anthropogenic effects in climate--paralleling significant increases in spatial synchrony of mean maximum air temperature. These results suggest the potential for increased spatial synchrony in environmental factors to be affecting a wide range of ecological phenomena. These effects are likely to vary, but for North American wildlife species, increased spatial synchrony driven by environmental factors may be the basis for a previously unrecognized threat to their long-term persistence in the form of more synchronized population dynamics reducing the potential for demographic rescue among interacting subpopulations.

Health benefits, ecological threats of low-carbon electricity

NASA Astrophysics Data System (ADS)

Gibon, Thomas; Hertwich, Edgar G.; Arvesen, Anders; Singh, Bhawna; Verones, Francesca

2017-03-01

Stabilizing global temperature will require a shift to renewable or nuclear power from fossil power and the large-scale deployment of CO2 capture and storage (CCS) for remaining fossil fuel use. Non-climate co-benefits of low-carbon energy technologies, especially reduced mortalities from air pollution and decreased ecosystem damage, have been important arguments for policies to reduce CO2 emissions. Taking into account a wide range of environmental mechanisms and the complex interactions of the supply chains of different technologies, we conducted the first life cycle assessment of potential human health and ecological impacts of a global low-carbon electricity scenario. Our assessment indicates strong human health benefits of low-carbon electricity. For ecosystem quality, there is a significant trade-off between reduced pollution and climate impacts and potentially significant ecological impacts from land use associated with increased biopower utilization. Other renewables, nuclear power and CCS show clear ecological benefits, so that the climate mitigation scenario with a relatively low share of biopower has lower ecosystem impacts than the baseline scenario. Energy policy can maximize co-benefits by supporting other renewable and nuclear power and developing biomass supply from sources with low biodiversity impact.

Home range and movements of Feral cats on Mauna Kea, Hawai'i

USGS Publications Warehouse

Goltz, Dan M.; Hess, S.C.; Brinck, K.W.; Banko, P.C.; Danner, R.M.

2008-01-01

Feral cats Felis catus in dry subalpine woodland of Mauna Kea, Hawai'i, live in low density and exhibit some of the largest reported home ranges in the literature. While 95% fixed kemel home range estimates for three females averaged 772 ha, four males averaged 1 418 ha, and one male maintained a home range of 2 050 ha. Mean daily movement rates between sexes overlapped widely and did not differ significantly (P = 0.083). Log-transformed 95% kernel home ranges for males were significantly larger than those of females (P = 0.024), but 25% kernel home ranges for females were larger than those of males (P = 0.017). Moreover, log-transformed home ranges of males were also significantly larger than those of females in this and seven other studies from the Pacific region (P = 0.044). Feral cats present a major threat to endangered Hawaiian birds, but knowledge of their ecology can be used for management by optimizing trap spacing and creating buffer zones around conservation areas.

Persistent ecological shifts in marine molluscan assemblages across the end-Cretaceous mass extinction.

PubMed

Aberhan, Martin; Kiessling, Wolfgang

2015-06-09

Contemporary biodiversity loss and population declines threaten to push the biosphere toward a tipping point with irreversible effects on ecosystem composition and function. As a potential example of a global-scale regime shift in the geological past, we assessed ecological changes across the end-Cretaceous mass extinction based on molluscan assemblages at four well-studied sites. By contrasting preextinction and postextinction rank abundance and numerical abundance in 19 molluscan modes of life--each defined as a unique combination of mobility level, feeding mode, and position relative to the substrate--we find distinct shifts in ecospace utilization, which significantly exceed predictions from null models. The magnitude of change in functional traits relative to normal temporal fluctuations at far-flung sites indicates that molluscan assemblages shifted to differently structured systems and faunal response was global. The strengths of temporal ecological shifts, however, are mostly within the range of preextinction site-to-site variability, demonstrating that local ecological turnover was similar to geographic variation over a broad latitudinal range. In conjunction with varied site-specific temporal patterns of individual modes of life, these spatial and temporal heterogeneities argue against a concerted phase shift of molluscan assemblages from one well-defined regime to another. At a broader ecological level, by contrast, congruent tendencies emerge and suggest deterministic processes. These patterns comprise the well-known increase of deposit-feeding mollusks in postextinction assemblages and increases in predators and predator-resistant modes of life, i.e., those characterized by elevated mobility and infaunal life habits.

Impact of climate change on vector transmission of Trypanosoma cruzi (Chagas, 1909) in North America.

PubMed

Carmona-Castro, O; Moo-Llanes, D A; Ramsey, J M

2018-03-01

Climate change can influence the geographical range of the ecological niche of pathogens by altering biotic interactions with vectors and reservoirs. The distributions of 20 epidemiologically important triatomine species in North America were modelled, comparing the genetic algorithm for rule-set prediction (GARP) and maximum entropy (MaxEnt), with or without topographical variables. Potential shifts in transmission niche for Trypanosoma cruzi (Trypanosomatida: Trypanosomatidae) (Chagas, 1909) were analysed for 2050 and 2070 in Representative Concentration Pathway (RCP) 4.5 and RCP 8.5. There were no significant quantitative range differences between the GARP and MaxEnt models, but GARP models best represented known distributions for most species [partial-receiver operating characteristic (ROC) > 1]; elevation was an important variable contributing to the ecological niche model (ENM). There was little difference between niche breadth projections for RCP 4.5 and RCP 8.5; the majority of species shifted significantly in both periods. Those species with the greatest current distribution range are expected to have the greatest shifts. Positional changes in the centroid, although reduced for most species, were associated with latitude. A significant increase or decrease in mean niche elevation is expected principally for Neotropical 1 species. The impact of climate change will be specific to each species, its biogeographical region and its latitude. North American triatomines with the greatest current distribution ranges (Nearctic 2 and Nearctic/Neotropical) will have the greatest future distribution shifts. Significant shifts (increases or decreases) in mean elevation over time are projected principally for the Neotropical species with the broadest current distributions. Changes in the vector exposure threat to the human population were significant for both future periods, with a 1.48% increase for urban populations and a 1.76% increase for rural populations in 2050. © 2017 The Royal Entomological Society.

Prokaryotic communities differ along a geothermal soil photic gradient.

PubMed

Meadow, James F; Zabinski, Catherine A

2013-01-01

Geothermal influenced soils exert unique physical and chemical limitations on resident microbial communities but have received little attention in microbial ecology research. These environments offer a model system in which to investigate microbial community heterogeneity and a range of soil ecological concepts. We conducted a 16S bar-coded pyrosequencing survey of the prokaryotic communities in a diatomaceous geothermal soil system and compared communities across soil types and along a conspicuous photic depth gradient. We found significant differences between the communities of the two different soils and also predictable differences between samples taken at different depths. Additionally, we targeted three ecologically relevant bacterial phyla, Cyanobacteria, Planctomycetes, and Verrucomicrobia, for clade-wise comparisons with these variables and found strong differences in their abundances, consistent with the autecology of these groups.

An ecological genetic delineation of local seed-source provenance for ecological restoration

PubMed Central

Krauss, Siegfried L; Sinclair, Elizabeth A; Bussell, John D; Hobbs, Richard J

2013-01-01

An increasingly important practical application of the analysis of spatial genetic structure within plant species is to help define the extent of local provenance seed collection zones that minimize negative impacts in ecological restoration programs. Here, we derive seed sourcing guidelines from a novel range-wide assessment of spatial genetic structure of 24 populations of Banksia menziesii (Proteaceae), a widely distributed Western Australian tree of significance in local ecological restoration programs. An analysis of molecular variance (AMOVA) of 100 amplified fragment length polymorphism (AFLP) markers revealed significant genetic differentiation among populations (ΦPT = 0.18). Pairwise population genetic dissimilarity was correlated with geographic distance, but not environmental distance derived from 15 climate variables, suggesting overall neutrality of these markers with regard to these climate variables. Nevertheless, Bayesian outlier analysis identified four markers potentially under selection, although these were not correlated with the climate variables. We calculated a global R-statistic using analysis of similarities (ANOSIM) to test the statistical significance of population differentiation and to infer a threshold seed collection zone distance of ∼60 km (all markers) and 100 km (outlier markers) when genetic distance was regressed against geographic distance. Population pairs separated by >60 km were, on average, twice as likely to be significantly genetically differentiated than population pairs separated by <60 km, suggesting that habitat-matched sites within a 30-km radius around a restoration site genetically defines a local provenance seed collection zone for B. menziesii. Our approach is a novel probability-based practical solution for the delineation of a local seed collection zone to minimize negative genetic impacts in ecological restoration. PMID:23919158

A Combined Ecological and Epidemiologic Investigation of Metals Exposure amongst Indigenous Peoples Near the Marlin Mine in Western Guatemala

PubMed Central

Basu, Niladri; Abare, Marce; Buchanan, Susan; Cryderman, Diana; Nam, Dong-Ha; Sirkin, Susannah; Schmitt, Stefan; Hu, Howard

2016-01-01

In August 2009 a combined epidemiological and ecological pilot study was conducted to investigate allegations of human rights abuses in the form of exposures to toxic metals experienced by mine workers and Indigenous Mam Mayan near the Marlin Mine in Guatemala. In the human study there were no differences in blood and urine metals when comparing five mine workers with eighteen non-mine workers, and there were no discernible relationships between metals exposures and self-reported health measures in any study group. On the other hand, individuals residing closest to the mine had significantly higher levels of certain metals (urinary mercury, copper, arsenic, zinc) when compared to those living further away. Levels of blood aluminum, manganese, and cobalt were elevated in comparison to established normal ranges in many individuals; however, there was no apparent relationship to proximity to the mine or occupation, and thus are of unclear significance. In the ecological study, several metals (aluminum, manganese, cobalt) were found significantly elevated in the river water and sediment sites directly below the mine when compared to sites elsewhere. When the results of the human and ecological results are combined, they suggest that exposures to certain metals may be elevated in sites near the mine but it is not clear if the current magnitude of these elevations poses a significant threat to health. The authors conclude that more robust studies are needed while parallel efforts to minimize the ecological and human impacts of mining proceed. This is critical particularly as the impact of the exposures found could be greatly magnified by expected increases in mining activity over time, synergistic toxicity between metals, and susceptibility for the young and those with pre-existing disease. PMID:20952048

Colorado River cutthroat trout: a technical conservation assessment

Treesearch

Michael K. Young

2008-01-01

The Colorado River cutthroat trout (Oncorhynchus clarkii pleuriticus) was once distributed throughout the colder waters of the Colorado River basin above the Grand Canyon. About 8 percent of its historical range is occupied by unhybridized or ecologically significant populations. It has been petitioned for listing under the Endangered Species Act...

Functional and evolutionary insights from the genomes of three parasitoid nasonia species

USDA-ARS?s Scientific Manuscript database

Parasitoid wasps are significant natural enemies of a broad range of arthropods with considerable ecological and economic impact. There are more species beneficial to humans among the parasitoid wasps than in any other insect group. They have haplodiploid sex determination (development of males from...

Longleaf pine regeneration ecology and methods

Treesearch

Dale G. Brockway; Kenneth W. Outcalt; William D. Boyer

2006-01-01

Regenerating longleaf pine (Pinus palustris) is key to its long-term sustainable production of forest resources and its perpetuation as the dominant tree species in a variety of important ecosystems ranging from xeric to mesic to hydric site conditions. Early regeneration to problems and the subsequent efforts to overcome these are significant...

Ecological risk assessment of cheese whey effluents along a medium-sized river in southwest Greece.

PubMed

Karadima, Constantina; Theodoropoulos, Chris; Rouvalis, Angela; Iliopoulou-Georgudaki, Joan

2010-01-01

An ecological risk assessment of cheese whey effluents was applied in three critical sampling sites located in Vouraikos river (southwest Greece), while ecological classification using Water Framework Directive 2000/60/EU criteria allowed a direct comparison of toxicological and ecological data. Two invertebrates (Daphnia magna and Thamnocephalus platyurus) and the zebra fish Danio rerio were used for toxicological analyses, while the aquatic risk was calculated on the basis of the risk quotient (RQ = PEC/PNEC). Chemical classification of sites was carried out using the Nutrient Classification System, while benthic invertebrates were collected and analyzed for biological classification. Toxicological results revealed the heavy pollution load of the two sites, nearest to the point pollution source, as the PEC/PNEC ratio exceeded 1.0, while unexpectedly, no risk was detected for the most downstream site, due to the consequent interference of the riparian flora. These toxicological results were in agreement with the ecological analysis: the ecological quality of the two heavily impacted sites ranged from moderate to bad, whereas it was found good for the most downstream site. The results of the study indicate major ecological risk for almost 15 km downstream of the point pollution source and the potentiality of the water quality remediation by the riparian vegetation, proving the significance of its maintenance.

River networks as ecological corridors: A coherent ecohydrological perspective

NASA Astrophysics Data System (ADS)

Rinaldo, Andrea; Gatto, Marino; Rodriguez-Iturbe, Ignacio

2018-02-01

This paper draws together several lines of argument to suggest that an ecohydrological framework, i.e. laboratory, field and theoretical approaches focused on hydrologic controls on biota, has contributed substantially to our understanding of the function of river networks as ecological corridors. Such function proves relevant to: the spatial ecology of species; population dynamics and biological invasions; the spread of waterborne disease. As examples, we describe metacommunity predictions of fish diversity patterns in the Mississippi-Missouri basin, geomorphic controls imposed by the fluvial landscape on elevational gradients of species' richness, the zebra mussel invasion of the same Mississippi-Missouri river system, and the spread of proliferative kidney disease in salmonid fish. We conclude that spatial descriptions of ecological processes in the fluvial landscape, constrained by their specific hydrologic and ecological dynamics and by the ecosystem matrix for interactions, i.e. the directional dispersal embedded in fluvial and host/pathogen mobility networks, have already produced a remarkably broad range of significant results. Notable scientific and practical perspectives are thus open, in the authors' view, to future developments in ecohydrologic research.

Influence of ecological factors on the production of active substances in the anti-cancer plant Sinopodophyllum hexandrum (Royle) T.S. Ying.

PubMed

Liu, Wei; Liu, Jianjun; Yin, Dongxue; Zhao, Xiaowen

2015-01-01

The quality of traditional Chinese herbal medicine, which plays a very important role in the health system of China, is determined by the active substances produced by the plants. The type, content, and proportion of these substances may vary depending on ecological factors in areas where the plants are grown. Sinopodophyllum hexandrum (Royle) T.S. Ying, an endangered plant species with great medical value, was investigated in eight production locations representative of its natural geographical distribution range in China. The correlation between the contents of the active ingredients extracted from the roots and rhizomes of S. hexandrum and the ecological factors were evaluated step-by-step using a series of computational biology methodologies. The results showed that ecological factors had significant effects on the contents but not on the types of the active ingredients in eight production locations. The primary ecological factors influencing the active substances included the annual average precipitation, July mean temperature, frost-free period, sunshine duration, soil pH, soil organic matter, and rapidly available potassium in the soil. The annual average precipitation was the most important determinant factor and was significantly and negatively correlated with the active ingredient contents (P < 0.001). In contrast, organic matter was the most important limiting factor and was significantly and positively correlated with the active substances. These ecological factors caused 98.13% of the total geographical variation of the active ingredient contents. The climate factors contributed more to the active ingredient contents than did the soil factors. It was concluded that from the view of the contents of the secondary metabolites and ecological factors of each growing location, in Jingyuan, Ningxia Province, and Yongdeng, Gansu Province, conditions were favorable to the production of podophyllotoxin and lignans, whereas in Shangri-La, Yunnan Province, and Nyingchi, Tibet, conditions were favorable to the production of quercetin and kaempferol.

Influence of Ecological Factors on the Production of Active Substances in the Anti-Cancer Plant Sinopodophyllum hexandrum (Royle) T.S. Ying

PubMed Central

Liu, Wei; Liu, Jianjun; Yin, Dongxue; Zhao, Xiaowen

2015-01-01

The quality of traditional Chinese herbal medicine, which plays a very important role in the health system of China, is determined by the active substances produced by the plants. The type, content, and proportion of these substances may vary depending on ecological factors in areas where the plants are grown. Sinopodophyllum hexandrum (Royle) T.S. Ying, an endangered plant species with great medical value, was investigated in eight production locations representative of its natural geographical distribution range in China. The correlation between the contents of the active ingredients extracted from the roots and rhizomes of S. hexandrum and the ecological factors were evaluated step-by-step using a series of computational biology methodologies. The results showed that ecological factors had significant effects on the contents but not on the types of the active ingredients in eight production locations. The primary ecological factors influencing the active substances included the annual average precipitation, July mean temperature, frost-free period, sunshine duration, soil pH, soil organic matter, and rapidly available potassium in the soil. The annual average precipitation was the most important determinant factor and was significantly and negatively correlated with the active ingredient contents (P < 0.001). In contrast, organic matter was the most important limiting factor and was significantly and positively correlated with the active substances. These ecological factors caused 98.13% of the total geographical variation of the active ingredient contents. The climate factors contributed more to the active ingredient contents than did the soil factors. It was concluded that from the view of the contents of the secondary metabolites and ecological factors of each growing location, in Jingyuan, Ningxia Province, and Yongdeng, Gansu Province, conditions were favorable to the production of podophyllotoxin and lignans, whereas in Shangri-La, Yunnan Province, and Nyingchi, Tibet, conditions were favorable to the production of quercetin and kaempferol. PMID:25874701

A study of ecological red-line area partitioning in the Chishui River Basin in Guizhou

NASA Astrophysics Data System (ADS)

Yang, S. F.; An, Y. L.

2016-08-01

Maintaining ecosystem balance and realizing the strategic goal of sustainable development are key objectives in the field of environmental sciences. Accordingly, drawing ecological red lines in sensitive and vulnerable environmental areas and important ecological function areas, determining the distribution range of ecological red-line areas, providing scientific guidance for developmental activities, and effectively managing the ecological environment are significant work tasks supported by policy guidance from the State Council and from knowledge gained in educational circles. Taking the Chishui River Basin in Guizhou as the study object, this research selected water and soil loss sensitivity, as well as assessments of karst rocky desertification sensitivity as background assessments of the eco-environment. Furthermore, the functions of soil conservation, water conservation, and biodiversity protection were integrated with exploitation-prohibited areas, and an organic combination of ecological needs and social service functions was created. Spatial comprehensive overlay analysis and processing revealed that the combination marked nine major ecological red-line areas in a total area of 5,030.58 km2, which occupied 44.16% of the total basin area. By combining the current eco-environmental situation of the Chishui River Basin with the marked out red-line areas, this research proposed corresponding ecological red-line area management suggestions. These suggestions are expected to provide a scientific foundation for eco-environmental protection and subsequent scientific research in Chishui River Basin.

The ecological niche and reciprocal prediction of the disjunct distribution of an invasive species: the example of Ailanthus altissima

Treesearch

Thomas P. Albright; Hao Chen; Lijun Chen; Qinfeng Guo

2010-01-01

Knowledge of the ecological niches of invasive species in native and introduced ranges can inform management as well as ecological and evolutionary theory. Here, we identified and compared factors associated with the distribution of an invasive tree, Ailanthus altissima, in both its native Chinese and introduced US ranges and predicted potential US...

Test of the ecological-constraints model on ursine colobus monkeys (Colobus vellerosus) in Ghana.

PubMed

Teichroeb, Julie A; Sicotte, Pascale

2009-01-01

For group-living mammals, the ecological-constraints model predicts that within-group feeding competition will increase as group size increases, necessitating more daily travel to find food and thereby constraining group size. It provides a useful tool for detecting scramble competition any time it is difficult to determine whether or not food is limiting. We tested the ecological-constraints model on highly folivorous ursine colobus monkeys (Colobus vellerosus) at the Boabeng-Fiema Monkey Sanctuary in Ghana. Three differently sized groups were followed for 13 months and two others were followed for 6 months each in 2004-2005 using focal-animal sampling and ranging scans; ecological plots and phenology surveys were used to determine home-range quality and food availability. There was relatively little difference in home-range quality, monthly food availability, diet, adult female ingestion rates, and rate of travel within food patches between the groups. However, home-range size, day-range length, and percent of time spent feeding all increased with group size. We performed a single large test of the ecological-constraints model by combining several separate Spearman correlations, each testing different predictions under the model, using Fisher's log-likelihood method. It showed that the ecological-constraints model was supported in this study; scramble competition in this population is manifesting in increased ranging and time spent feeding. How costly this increased energy expenditure is for individuals in larger groups remains to be determined. (c) 2008 Wiley-Liss, Inc.

A Systematic Review and Meta-Regression Analysis of Lung Cancer Risk and Inorganic Arsenic in Drinking Water.

PubMed

Lamm, Steven H; Ferdosi, Hamid; Dissen, Elisabeth K; Li, Ji; Ahn, Jaeil

2015-12-07

High levels (> 200 µg/L) of inorganic arsenic in drinking water are known to be a cause of human lung cancer, but the evidence at lower levels is uncertain. We have sought the epidemiological studies that have examined the dose-response relationship between arsenic levels in drinking water and the risk of lung cancer over a range that includes both high and low levels of arsenic. Regression analysis, based on six studies identified from an electronic search, examined the relationship between the log of the relative risk and the log of the arsenic exposure over a range of 1-1000 µg/L. The best-fitting continuous meta-regression model was sought and found to be a no-constant linear-quadratic analysis where both the risk and the exposure had been logarithmically transformed. This yielded both a statistically significant positive coefficient for the quadratic term and a statistically significant negative coefficient for the linear term. Sub-analyses by study design yielded results that were similar for both ecological studies and non-ecological studies. Statistically significant X-intercepts consistently found no increased level of risk at approximately 100-150 µg/L arsenic.

A Systematic Review and Meta-Regression Analysis of Lung Cancer Risk and Inorganic Arsenic in Drinking Water

PubMed Central

Lamm, Steven H.; Ferdosi, Hamid; Dissen, Elisabeth K.; Li, Ji; Ahn, Jaeil

2015-01-01

High levels (> 200 µg/L) of inorganic arsenic in drinking water are known to be a cause of human lung cancer, but the evidence at lower levels is uncertain. We have sought the epidemiological studies that have examined the dose-response relationship between arsenic levels in drinking water and the risk of lung cancer over a range that includes both high and low levels of arsenic. Regression analysis, based on six studies identified from an electronic search, examined the relationship between the log of the relative risk and the log of the arsenic exposure over a range of 1–1000 µg/L. The best-fitting continuous meta-regression model was sought and found to be a no-constant linear-quadratic analysis where both the risk and the exposure had been logarithmically transformed. This yielded both a statistically significant positive coefficient for the quadratic term and a statistically significant negative coefficient for the linear term. Sub-analyses by study design yielded results that were similar for both ecological studies and non-ecological studies. Statistically significant X-intercepts consistently found no increased level of risk at approximately 100–150 µg/L arsenic. PMID:26690190

The movement ecology of seagrasses

PubMed Central

McMahon, Kathryn; van Dijk, Kor-jent; Ruiz-Montoya, Leonardo; Kendrick, Gary A.; Krauss, Siegfried L.; Waycott, Michelle; Verduin, Jennifer; Lowe, Ryan; Statton, John; Brown, Eloise; Duarte, Carlos

2014-01-01

A movement ecology framework is applied to enhance our understanding of the causes, mechanisms and consequences of movement in seagrasses: marine, clonal, flowering plants. Four life-history stages of seagrasses can move: pollen, sexual propagules, vegetative fragments and the spread of individuals through clonal growth. Movement occurs on the water surface, in the water column, on or in the sediment, via animal vectors and through spreading clones. A capacity for long-distance dispersal and demographic connectivity over multiple timeframes is the novel feature of the movement ecology of seagrasses with significant evolutionary and ecological consequences. The space–time movement footprint of different life-history stages varies. For example, the distance moved by reproductive propagules and vegetative expansion via clonal growth is similar, but the timescales range exponentially, from hours to months or centuries to millennia, respectively. Consequently, environmental factors and key traits that interact to influence movement also operate on vastly different spatial and temporal scales. Six key future research areas have been identified. PMID:25297859

Gaining perspective on what we've lost: the reliability of encoded anecdotes in historical ecology.

PubMed

Al-Abdulrazzak, Dalal; Naidoo, Robin; Palomares, Maria Lourdes D; Pauly, Daniel

2012-01-01

Historical data are essential in fisheries management and conservation, especially for species that suffered significant population declines prior to ecological data collection. Within the field of historical marine ecology, studies have relied on anecdotal evidence, such as written accounts by explorers and interviews of different generations of resource users, to demonstrate the former abundance of certain species and the extent of their ranges. Yet, do we all agree on how these anecdotes are interpreted? This study examines the way that different people interpret anecdotes extracted from historical narratives. We outsource a survey to 50 randomly selected people using Amazon Mechanical Turk (www.mturk.com) and ask them to 'code' historical anecdotes based on their perceived abundance of species. We perform intercoder reliability tests to show that people's perceptions of historical anecdotes are generally consistent. The results speak to the reliability of using people's perceptions to acquire quantitative data, and provide novel insights into the use of anecdotal evidence to inform historical ecology.

Polycyclic aromatic hydrocarbons (PAH) in superficial water from a tropical estuarine system: Distribution, seasonal variations, sources and ecological risk assessment.

PubMed

Santos, Ewerton; Souza, Michel R R; Vilela Junior, Antônio R; Soares, Laiane S; Frena, Morgana; Alexandre, Marcelo R

2018-02-01

This study aimed to evaluate the PAH distribution, sources, seasonal variations and ecological risk assessment in superficial water from the Japaratuba River, Brazil. PAH concentrations ranged from 4 to 119ngL -1 . It was observed that the PAH total concentrations and profiles showed significant differences when comparing the dry season (summer) with the rainy season (winter). Furthermore, most of the PAH originated from pyrogenic sources in the winter, whereas a mixture of sources was observed in the summer. PAH concentration levels found in this study were considered lower than those obtained in other estuarine systems. Ecological risk assessment was determined for individual PAH, based on the risk quotient (RQ) to evaluate the risk of aquatic biota's exposure to PAH. Results suggested that the Japaratuba River has achieved a moderate degree of ecological risk for high molecular weight, showing the importance of identifying these carcinogenic and mutagenic compounds in aquatic systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

Phylogenetic patterns of geographical and ecological diversification in the subgenus Drosophila.

PubMed

Morales-Hojas, Ramiro; Vieira, Jorge

2012-01-01

Colonisation of new geographic regions and/or of new ecological resources can result in rapid species diversification into the new ecological niches available. Members of the subgenus Drosophila are distributed across the globe and show a large diversity of ecological niches. Furthermore, taxonomic classification of Drosophila includes the rank radiation, which refers to closely related species groups. Nevertheless, it has never been tested if these taxonomic radiations correspond to evolutionary radiations. Here we present a study of the patterns of diversification of Drosophila to test for increased diversification rates in relation to the geographic and ecological diversification processes. For this, we have estimated and dated a phylogeny of 218 species belonging to the major species groups of the subgenus. The obtained phylogenies are largely consistent with previous studies and indicate that the major groups appeared during the Oligocene/Miocene transition or early Miocene, characterized by a trend of climate warming with brief periods of glaciation. Ancestral reconstruction of geographic ranges and ecological resource use suggest at least two dispersals to the Neotropics from the ancestral Asiatic tropical disribution, and several transitions to specialized ecological resource use (mycophagous and cactophilic). Colonisation of new geographic regions and/or of new ecological resources can result in rapid species diversification into the new ecological niches available. However, diversification analyses show no significant support for adaptive radiations as a result of geographic dispersal or ecological resource shift. Also, cactophily has not resulted in an increase in the diversification rate of the repleta and related groups. It is thus concluded that the taxonomic radiations do not correspond to adaptive radiations.

Uneven-aged management of longleaf pine forests: a scientist and manager dialogue

Treesearch

Dale G. Brockway; Kenneth W. Outcalt; James M. Guldin; William D. Boyer; Joan L. Walker; D. Craig Rudolph; Robert B. Rummer; James P. Barnett; Shibu Jose; Jarek Nowak

2005-01-01

Interest in appropriate management approaches for sustaining longleaf pine (Pinus palustris Mill.) forests has increased substantially during the recent decade. Although long-leaf pine can be managed using even-aged techniques, interest in uneven-aged methods has grown significantly as a result of concern for sustaining the wide range of ecological...

Species' Traits as Predictors of Range Shifts Under Contemporary Climate Change: A Meta-analysis

NASA Astrophysics Data System (ADS)

MacLean, S. A.; Beissinger, S. R.

2016-12-01

A growing body of literature seeks to explain variation in range shifts using species' ecological and life history traits, with expectations that shifts should be greater in species with greater dispersal ability, reproductive potential, and ecological generalization. If trait-based arguments, hold, then traits would provide valuable evidence-based tools for conservation and management that could increase the accuracy of future range projections, vulnerability assessments, and predictions of novel community assemblages. However, empirical support is limited in extent and consensus, and trait-based relationships remain largely unvalidated. We conducted a comprehensive literature review of species' traits as predictors of range shifts, collecting results from over 11,000 species' responses across multiple taxa from studies that directly compared 20th century and contemporary distributions for multispecies assemblages. We then performed a meta-analysis to calculate the mean study-level effects of body size, fecundity, diet breadth, habitat breadth, and historic range limit, while directly controlling for ecological and methodological heterogeneity across studies that could bias reported effect sizes. We show that ecological and life history traits have had limited success in accounting for variation among species in range shifts over the past century. Of the five traits analyzed, only habitat breadth and historic range limit consistently supported range shift predictions across multiple studies. Fecundity, body size, and diet breadth showed no clear relationship with range shifts, and some traits identified in our literature review (e.g. migratory ecology) have consistently contradicted range shift predictions. Current understanding of species' traits as predictors of range shifts is limited, and standardized study is needed before traits can be reliably incorporated into projections of climate change impacts.

Microfluidics Expanding the Frontiers of Microbial Ecology

PubMed Central

Rusconi, Roberto; Garren, Melissa; Stocker, Roman

2014-01-01

The ability afforded by microfluidics to observe the behaviors of microbes in highly controlled and confined microenvironments, across scales from a single cell to mixed communities, has significantly contributed to expand the frontiers of microbial ecology over the last decade. Spatially and temporally varying distributions of organisms and chemical cues that mimic natural microbial habitats can now be established by exploiting physics at the micrometer scale and by incorporating structures with specific geometries and materials. Here we review applications of microfluidics that have resulted in highly insightful discoveries on fundamental aspects of microbial life, ranging from growth and sensing to cell-cell interactions and population dynamics. We anticipate that this flexible, multidisciplinary technology will continue to facilitate discoveries regarding the ecology of microorganisms and help uncover strategies to control phenomena such as biofilm formation and antibiotic resistance. PMID:24773019

Microfluidics expanding the frontiers of microbial ecology.

PubMed

Rusconi, Roberto; Garren, Melissa; Stocker, Roman

2014-01-01

Microfluidics has significantly contributed to the expansion of the frontiers of microbial ecology over the past decade by allowing researchers to observe the behaviors of microbes in highly controlled microenvironments, across scales from a single cell to mixed communities. Spatially and temporally varying distributions of organisms and chemical cues that mimic natural microbial habitats can now be established by exploiting physics at the micrometer scale and by incorporating structures with specific geometries and materials. In this article, we review applications of microfluidics that have resulted in insightful discoveries on fundamental aspects of microbial life, ranging from growth and sensing to cell-cell interactions and population dynamics. We anticipate that this flexible multidisciplinary technology will continue to facilitate discoveries regarding the ecology of microorganisms and help uncover strategies to control microbial processes such as biofilm formation and antibiotic resistance.

Ecological allometries and niche use dynamics across Komodo dragon ontogeny.

PubMed

Purwandana, Deni; Ariefiandy, Achmad; Imansyah, M Jeri; Seno, Aganto; Ciofi, Claudio; Letnic, Mike; Jessop, Tim S

2016-04-01

Ontogenetic allometries in ecological habits and niche use are key responses by which individuals maximize lifetime fitness. Moreover, such allometries have significant implications for how individuals influence population and community dynamics. Here, we examined how body size variation in Komodo dragons (Varanus komodoensis) influenced ecological allometries in their: (1) prey size preference, (2) daily movement rates, (3) home range area, and (4) subsequent niche use across ontogeny. With increased body mass, Komodo dragons increased prey size with a dramatic switch from small (≤10 kg) to large prey (≥50 kg) in lizards heavier than 20 kg. Rates of foraging movement were described by a non-linear concave down response with lizard increasing hourly movement rates up until ∼20 kg body mass before decreasing daily movement suggesting reduced foraging effort in larger lizards. In contrast, home range area exhibited a sigmoid response with increased body mass. Intrapopulation ecological niche use and overlap were also strongly structured by body size. Thus, ontogenetic allometries suggest Komodo dragon's transition from a highly active foraging mode exploiting small prey through to a less active sit and wait feeding strategy focused on killing large ungulates. Further, our results suggest that as body size increases across ontogeny, the Komodo dragon exhibited marked ontogenetic niche shifts that enabled it to function as an entire vertebrate predator guild by exploiting prey across multiple trophic levels.

Ecological allometries and niche use dynamics across Komodo dragon ontogeny

NASA Astrophysics Data System (ADS)

Purwandana, Deni; Ariefiandy, Achmad; Imansyah, M. Jeri; Seno, Aganto; Ciofi, Claudio; Letnic, Mike; Jessop, Tim S.

2016-04-01

Ontogenetic allometries in ecological habits and niche use are key responses by which individuals maximize lifetime fitness. Moreover, such allometries have significant implications for how individuals influence population and community dynamics. Here, we examined how body size variation in Komodo dragons ( Varanus komodoensis) influenced ecological allometries in their: (1) prey size preference, (2) daily movement rates, (3) home range area, and (4) subsequent niche use across ontogeny. With increased body mass, Komodo dragons increased prey size with a dramatic switch from small (≤10 kg) to large prey (≥50 kg) in lizards heavier than 20 kg. Rates of foraging movement were described by a non-linear concave down response with lizard increasing hourly movement rates up until ˜20 kg body mass before decreasing daily movement suggesting reduced foraging effort in larger lizards. In contrast, home range area exhibited a sigmoid response with increased body mass. Intrapopulation ecological niche use and overlap were also strongly structured by body size. Thus, ontogenetic allometries suggest Komodo dragon's transition from a highly active foraging mode exploiting small prey through to a less active sit and wait feeding strategy focused on killing large ungulates. Further, our results suggest that as body size increases across ontogeny, the Komodo dragon exhibited marked ontogenetic niche shifts that enabled it to function as an entire vertebrate predator guild by exploiting prey across multiple trophic levels.

Pollination Mode and Mating System Explain Patterns in Genetic Differentiation in Neotropical Plants

PubMed Central

Ballesteros-Mejia, Liliana; Lima, Natácia E.; Lima-Ribeiro, Matheus S.

2016-01-01

We studied genetic diversity and differentiation patterns in Neotropical plants to address effects of life history traits (LHT) and ecological attributes based on an exhaustive literature survey. We used generalized linear mixed models (GLMMs) to test the effects as fixed and random factors of growth form, pollination and dispersal modes, mating and breeding systems, geographical range and habitat on patterns of genetic diversity (HS, HeS, π and h), inbreeding coefficient (FIS), allelic richness (AR) and differentiation among populations (FST) for both nuclear and chloroplast genomes. In addition, we used phylogenetic generalized least squares (pGLS) to account for phylogenetic independence on predictor variables and verify the robustness of the results from significant GLMMs. In general, GLMM revealed more significant relationships among LHTs and genetic patterns than pGLS. After accounting for phylogenetic independence (i.e., using pGLS), FST for nuclear microsatellites was significantly related to pollination mode, mating system and habitat. Plants specifically with outcrossing mating system had lower FST. Moreover, AR was significantly related to pollination mode and geographical range and HeS for nuclear dominant markers was significantly related to habitat. Our findings showed that different results might be retrieved when phylogenetic non-independence is taken into account and that LHTs and ecological attributes affect substantially the genetic pattern in Neotropical plants, hence may drive key evolutionary processes in plants. PMID:27472384

A confidence interval analysis of sampling effort, sequencing depth, and taxonomic resolution of fungal community ecology in the era of high-throughput sequencing.

PubMed

Oono, Ryoko

2017-01-01

High-throughput sequencing technology has helped microbial community ecologists explore ecological and evolutionary patterns at unprecedented scales. The benefits of a large sample size still typically outweigh that of greater sequencing depths per sample for accurate estimations of ecological inferences. However, excluding or not sequencing rare taxa may mislead the answers to the questions 'how and why are communities different?' This study evaluates the confidence intervals of ecological inferences from high-throughput sequencing data of foliar fungal endophytes as case studies through a range of sampling efforts, sequencing depths, and taxonomic resolutions to understand how technical and analytical practices may affect our interpretations. Increasing sampling size reliably decreased confidence intervals across multiple community comparisons. However, the effects of sequencing depths on confidence intervals depended on how rare taxa influenced the dissimilarity estimates among communities and did not significantly decrease confidence intervals for all community comparisons. A comparison of simulated communities under random drift suggests that sequencing depths are important in estimating dissimilarities between microbial communities under neutral selective processes. Confidence interval analyses reveal important biases as well as biological trends in microbial community studies that otherwise may be ignored when communities are only compared for statistically significant differences.

A confidence interval analysis of sampling effort, sequencing depth, and taxonomic resolution of fungal community ecology in the era of high-throughput sequencing

PubMed Central

2017-01-01

High-throughput sequencing technology has helped microbial community ecologists explore ecological and evolutionary patterns at unprecedented scales. The benefits of a large sample size still typically outweigh that of greater sequencing depths per sample for accurate estimations of ecological inferences. However, excluding or not sequencing rare taxa may mislead the answers to the questions ‘how and why are communities different?’ This study evaluates the confidence intervals of ecological inferences from high-throughput sequencing data of foliar fungal endophytes as case studies through a range of sampling efforts, sequencing depths, and taxonomic resolutions to understand how technical and analytical practices may affect our interpretations. Increasing sampling size reliably decreased confidence intervals across multiple community comparisons. However, the effects of sequencing depths on confidence intervals depended on how rare taxa influenced the dissimilarity estimates among communities and did not significantly decrease confidence intervals for all community comparisons. A comparison of simulated communities under random drift suggests that sequencing depths are important in estimating dissimilarities between microbial communities under neutral selective processes. Confidence interval analyses reveal important biases as well as biological trends in microbial community studies that otherwise may be ignored when communities are only compared for statistically significant differences. PMID:29253889

Chemical Speciation and Quantitative Evaluation of Heavy Metal Pollution Hazards in Two Army Shooting Range Backstop Soils.

PubMed

Islam, Mohammad Nazrul; Nguyen, Xuan Phuc; Jung, Ho-Young; Park, Jeong-Hun

2016-02-01

The chemical speciation and ecological risk assessment of heavy metals in two shooting range backstop soils in Korea were studied. Both soils were highly contaminated with Cd, Cu, Pb, and Sb. The chemical speciation of heavy metals reflected the present status of contamination, which could help in promoting management practices. We-rye soil had a higher proportion of exchangeable and carbonate bound metals and water-extractable Cd and Sb than the Cho-do soil. Bioavailable Pb represented 42 % of the total Pb content in both soils. A significant amount of Sb was found in the two most bioavailable fractions, amounting to ~32 % in the soil samples, in good agreement with the batch leaching test using water. Based on the values of ecological risk indices, both soils showed extremely high potential risk and may represent serious environmental problems.

The use of ecological classification in management

Treesearch

Constance A. Carpenter; Wolf-Dieter Busch; David T. Cleland; Juan Gallegos; Rick Harris; ray Holm; Chris Topik; Al Williamson

1999-01-01

Ecological classificafion systems range over a variety of scales and reflect a variety of scientific viewpoints. They incorporate or emphasize varied arrays of environmental factors. Ecological classifications have been developed for marine, wetland, lake, stream, and terrestrial ecosystems. What are the benefits of ecological classification for natural resource...

Impacts of Fire Ecology Range Management (FERM) on the Fate and Transport of Energetic Materials on Testing and Training Ranges

DTIC Science & Technology

2006-04-01

be significantly reduced or eliminated. Phytoremediation . Plants can have important effects on the fate and distribution of energetic compounds...place, and they can act as a surface for adherence of energetic compounds. Phytoremediation is frequently applied as a plant based remedial...intermediate log Kow (0.5 to 4) tend to be good targets 2 for phytoremediation because they are taken up by the roots and considered xylem mobile and

Impacts of biogeographic history and marginal population genetics on species range limits: a case study of Liriodendron chinense.

PubMed

Yang, Aihong; Dick, Christopher W; Yao, Xiaohong; Huang, Hongwen

2016-05-10

Species ranges are influenced by past climate oscillations, geographical constraints, and adaptive potential to colonize novel habitats at range limits. This study used Liriodendron chinense, an important temperate Asian tree species, as a model system to evaluate the roles of biogeographic history and marginal population genetics in determining range limits. We examined the demographic history and genetic diversity of 29 L. chinense populations using both chloroplast and nuclear microsatellite loci. Significant phylogeographic structure was recovered with haplotype clusters coinciding with major mountain regions. Long-term demographical stability was suggested by mismatch distribution analyses, neutrality tests, and ecological niche models (ENM) and suggested the existence of LGM refuges within mountain regions. Differences in genetic diversity between central and marginal populations were not significant for either genomic region. However, asymmetrical gene flow was inferred from central populations to marginal populations, which could potentially limit range adaptation and expansion of L. chinense.

Reinventing the Wheel: Teaching Restoration Ecology without the Ecology

ERIC Educational Resources Information Center

Speldewinde, Peter

2010-01-01

Restoration ecology is "the process of assisting the recovery of an ecosystem that has been degraded, damaged or destroyed." Restoration can range from returning the system to its "natural" state through to restoring some ecological functionality to a system. The University of Western Australia offers an undergraduate degree in…

Recognizing history in range ecology: 100 years of science and management on the Santa Rita Experimental Range

Treesearch

Nathan F. Sayre

2003-01-01

At the centennial of the Santa Rita Experimental Range, historical analysis is called for on two levels. First, as a major site in the history of range ecology, the Santa Rita illuminates past successes and failures in science and management and the ways in which larger social, economic, and political factors have shaped scientific research. Second, with the turn away...

In search of a general theory of species' range evolution.

PubMed

Connallon, Tim; Sgrò, Carla M

2018-06-13

Despite the pervasiveness of the world's biodiversity, no single species has a truly global distribution. In fact, most species have very restricted distributions. What limits species from expanding beyond their current geographic ranges? This has been classically treated by ecologists as an ecological problem and by evolutionary biologist as an evolutionary problem. Such a dichotomy is false-the problem of species' ranges sits firmly within the realm of evolutionary ecology. In support of this view, Polechová presents new theory that explains species' range limits with reference to two key factors central to both ecological and evolutionary theory-migration and population size. This new model sets the scene for empirical tests of range limit theory and builds the case for assisted gene flow as a key management tool for threatened species.

High-performance spider webs: integrating biomechanics, ecology and behaviour

PubMed Central

Harmer, Aaron M. T.; Blackledge, Todd A.; Madin, Joshua S.; Herberstein, Marie E.

2011-01-01

Spider silks exhibit remarkable properties, surpassing most natural and synthetic materials in both strength and toughness. Orb-web spider dragline silk is the focus of intense research by material scientists attempting to mimic these naturally produced fibres. However, biomechanical research on spider silks is often removed from the context of web ecology and spider foraging behaviour. Similarly, evolutionary and ecological research on spiders rarely considers the significance of silk properties. Here, we highlight the critical need to integrate biomechanical and ecological perspectives on spider silks to generate a better understanding of (i) how silk biomechanics and web architectures interacted to influence spider web evolution along different structural pathways, and (ii) how silks function in an ecological context, which may identify novel silk applications. An integrative, mechanistic approach to understanding silk and web function, as well as the selective pressures driving their evolution, will help uncover the potential impacts of environmental change and species invasions (of both spiders and prey) on spider success. Integrating these fields will also allow us to take advantage of the remarkable properties of spider silks, expanding the range of possible silk applications from single threads to two- and three-dimensional thread networks. PMID:21036911

An ecological and evolutionary perspective on the parallel invasion of two cross-compatible trees

PubMed Central

Besnard, Guillaume; Cuneo, Peter

2016-01-01

Invasive trees are generally seen as ecosystem-transforming plants that can have significant impacts on native vegetation, and often require management and control. Understanding their history and biology is essential to guide actions of land managers. Here, we present a summary of recent research into the ecology, phylogeography and management of invasive olives, which are now established outside of their native range as high ecological impact invasive trees. The parallel invasion of European and African olive in different climatic zones of Australia provides an interesting case study of invasion, characterized by early genetic admixture between domesticated and wild taxa. Today, the impact of the invasive olives on native vegetation and ecosystem function is of conservation concern, with European olive a declared weed in areas of South Australia, and African olive a declared weed in New South Wales and Pacific islands. Population genetics was used to trace the origins and invasion of both subspecies in Australia, indicating that both olive subspecies have hybridized early after introduction. Research also indicates that African olive populations can establish from a low number of founder individuals even after successive bottlenecks. Modelling based on distributional data from the native and invasive range identified a shift of the realized ecological niche in the Australian invasive range for both olive subspecies, which was particularly marked for African olive. As highly successful and long-lived invaders, olives offer further opportunities to understand the genetic basis of invasion, and we propose that future research examines the history of introduction and admixture, the genetic basis of adaptability and the role of biotic interactions during invasion. Advances on these questions will ultimately improve predictions on the future olive expansion and provide a solid basis for better management of invasive populations. PMID:27519914

Unveiling the conservation biogeography of a data-deficient endangered bird species under climate change.

PubMed

Hu, Junhua; Liu, Yang

2014-01-01

It remains a challenge to identify the geographical patterns and underlying environmental associations of species with unique ecological niches and distinct behaviors. This in turn hinders our understanding of the ecology as well as effective conservation management of threatened species. The white-eared night heron (Gorsachius magnificus) is a non-migratory nocturnal bird species that has a patchy distribution in the mountainous forests of East Asia. It is currently categorized as "Endangered" on the IUCN Red List, primarily due to its restricted range and fragmented habitat. To improve our knowledge of the biogeography and conservation of this species, we modeled the geographical pattern of its suitable habitat and evaluated the potential impacts of climate change using ecological niche modeling with a maximum entropy approach implemented in Maxent. Our results indicated that the amount of suitable habitat in all of East Asia was about 130 000 km(2), which can be spatially subdivided into several mountain ranges in southern and southwestern China and northern Vietnam. The extent of suitable habitat range may shrink by more than 35% under a predicted changing climate when assuming the most pessimistic condition of dispersal, while some more suitable habitat would be available if the heron could disperse unrestrainedly. The significant future changes in habitat suitability suggested for Gorsachius magnificus urge caution in any downgrading of Red List status that may be considered. Our results also discern potentially suitable areas for future survey efforts on new populations. Overall, this study demonstrates that ecological niche modeling offers an important tool for evaluating the habitat suitability and potential impacts of climate change on an enigmatic and endangered species based on limited presence data.

Range contractions of the world's large carnivores

PubMed Central

2017-01-01

The majority of the world's terrestrial large carnivores have undergone substantial range contractions and many of these species are currently threatened with extinction. However, there has been little effort to fully quantify the extent of large carnivore range contractions, which hinders our ability to understand the roles and relative drivers of such trends. Here we present and analyse a newly constructed and comprehensive set of large carnivore range contraction maps. We reveal the extent to which ranges have contracted since historical times and identify regions and biomes where range contractions have been particularly large. In summary, large carnivores that have experienced the greatest range contractions include the red wolf (Canis rufus) (greater than 99%), Ethiopian wolf (Canis simensis) (99%), tiger (Panthera tigris) (95%) and lion (Panthera leo) (94%). In general, the greatest range contractions occurred in Southeastern Asia and Africa. Motivated by the ecological importance of intact large carnivore guilds, we also examined the spatial extent of intact large carnivore guilds both for the entire world and regionally. We found that intact carnivore guilds occupy just 34% of the world's land area. This compares to 96% in historic times. Spatial modelling of range contractions showed that contractions were significantly more likely in regions with high rural human population density, cattle density or cropland. Our results offer new insights into how best to prevent further range contractions for the world's largest carnivores, which will assist efforts to conserve these species and their important ecological effects. PMID:28791136

Range contractions of the world's large carnivores.

PubMed

Wolf, Christopher; Ripple, William J

2017-07-01

The majority of the world's terrestrial large carnivores have undergone substantial range contractions and many of these species are currently threatened with extinction. However, there has been little effort to fully quantify the extent of large carnivore range contractions, which hinders our ability to understand the roles and relative drivers of such trends. Here we present and analyse a newly constructed and comprehensive set of large carnivore range contraction maps. We reveal the extent to which ranges have contracted since historical times and identify regions and biomes where range contractions have been particularly large. In summary, large carnivores that have experienced the greatest range contractions include the red wolf ( Canis rufus ) (greater than 99%), Ethiopian wolf ( Canis simensis ) (99%), tiger ( Panthera tigris ) (95%) and lion ( Panthera leo ) (94%). In general, the greatest range contractions occurred in Southeastern Asia and Africa. Motivated by the ecological importance of intact large carnivore guilds, we also examined the spatial extent of intact large carnivore guilds both for the entire world and regionally. We found that intact carnivore guilds occupy just 34% of the world's land area. This compares to 96% in historic times. Spatial modelling of range contractions showed that contractions were significantly more likely in regions with high rural human population density, cattle density or cropland. Our results offer new insights into how best to prevent further range contractions for the world's largest carnivores, which will assist efforts to conserve these species and their important ecological effects.

Ecological Insights from Pelagic Habitats Acquired Using Active Acoustic Techniques.

PubMed

Benoit-Bird, Kelly J; Lawson, Gareth L

2016-01-01

Marine pelagic ecosystems present fascinating opportunities for ecological investigation but pose important methodological challenges for sampling. Active acoustic techniques involve producing sound and receiving signals from organisms and other water column sources, offering the benefit of high spatial and temporal resolution and, via integration into different platforms, the ability to make measurements spanning a range of spatial and temporal scales. As a consequence, a variety of questions concerning the ecology of pelagic systems lend themselves to active acoustics, ranging from organism-level investigations and physiological responses to the environment to ecosystem-level studies and climate. As technologies and data analysis methods have matured, the use of acoustics in ecological studies has grown rapidly. We explore the continued role of active acoustics in addressing questions concerning life in the ocean, highlight creative applications to key ecological themes ranging from physiology and behavior to biogeography and climate, and discuss emerging avenues where acoustics can help determine how pelagic ecosystems function.

Bioclimatic models estimate areas with suitable climate for Armillaria spp. in Wyoming

Treesearch

James T. Blodgett; John W. Hanna; Eric W. I. Pitman; Sara M. Ashiglar; John E. Lundquist; Mee-Sook Kim; Amy L. Ross-Davis; Ned B. Klopfenstein

2015-01-01

Armillaria species range from beneficial saprobes to damaging root pathogens, and their ecological roles and impacts vary with environment and host. Armillaria solidipes [pending vote to conserve A. ostoyae . (Redhead et al. 2011 )] is known as an aggressive pathogen of conifers and causes tree mortality and significant growth loss in Wyoming and throughout...

North American Forest Futures 2018-2090: Scenarios for Building a More Resilient Forest Sector

Treesearch

David N. Bengston; Jonathan Peck; Robert Olson; Melissa Barros; Richard A. Birdsey; Daniel R. Williams; Juan Carlos Leyva Reyes; Francisco José Zamudio

2018-01-01

North American forests and forest management institutions are experiencing a wide range of significant ecological disturbances and socioeconomic changes, which point to the need for enhanced resilience. A critical capacity for resilience in institutions is strategic foresight. This article reports on a project of the North American Forest Commission to use Futures...

An Ecological Assessment of the Pandemic Threat of Zika Virus

PubMed Central

Getz, Wayne

2016-01-01

The current outbreak of Zika virus poses a severe threat to human health. While the range of the virus has been cataloged growing slowly over the last 50 years, the recent explosive expansion in the Americas indicates that the full potential distribution of Zika remains uncertain. Moreover, many studies rely on its similarity to dengue fever, a phylogenetically closely related disease of unknown ecological comparability. Here we compile a comprehensive spatially-explicit occurrence dataset from Zika viral surveillance and serological surveys based in its native range, and construct ecological niche models to test basic hypotheses about its spread and potential establishment. The hypothesis that the outbreak of cases in Mexico and North America are anomalous and outside the native ecological niche of the disease, and may be linked to either genetic shifts between strains, or El Nino or similar climatic events, remains plausible at this time. Comparison of the Zika niche against the known distribution of dengue fever suggests that Zika is more constrained by the seasonality of precipitation and diurnal temperature fluctuations, likely confining autochthonous non-sexual transmission to the tropics without significant evolutionary change. Projecting the range of the diseases in conjunction with three major vector species (Aedes africanus, Ae. aegypti, and Ae. albopictus) that transmit the pathogens, under climate change, suggests that Zika has potential for northward expansion; but, based on current knowledge, our models indicate Zika is unlikely to fill the full range its vectors occupy, and public fear of a vector-borne Zika epidemic in the mainland United States is potentially informed by biased or limited scientific knowledge. With recent sexual transmission of the virus globally, we caution that our results only apply to the vector-borne transmission route of the pathogen, and while the threat of a mosquito-carried Zika pandemic may be overstated in the media, other transmission modes of the virus may emerge and facilitate naturalization worldwide. PMID:27564232

An Ecological Assessment of the Pandemic Threat of Zika Virus.

PubMed

Carlson, Colin J; Dougherty, Eric R; Getz, Wayne

2016-08-01

The current outbreak of Zika virus poses a severe threat to human health. While the range of the virus has been cataloged growing slowly over the last 50 years, the recent explosive expansion in the Americas indicates that the full potential distribution of Zika remains uncertain. Moreover, many studies rely on its similarity to dengue fever, a phylogenetically closely related disease of unknown ecological comparability. Here we compile a comprehensive spatially-explicit occurrence dataset from Zika viral surveillance and serological surveys based in its native range, and construct ecological niche models to test basic hypotheses about its spread and potential establishment. The hypothesis that the outbreak of cases in Mexico and North America are anomalous and outside the native ecological niche of the disease, and may be linked to either genetic shifts between strains, or El Nino or similar climatic events, remains plausible at this time. Comparison of the Zika niche against the known distribution of dengue fever suggests that Zika is more constrained by the seasonality of precipitation and diurnal temperature fluctuations, likely confining autochthonous non-sexual transmission to the tropics without significant evolutionary change. Projecting the range of the diseases in conjunction with three major vector species (Aedes africanus, Ae. aegypti, and Ae. albopictus) that transmit the pathogens, under climate change, suggests that Zika has potential for northward expansion; but, based on current knowledge, our models indicate Zika is unlikely to fill the full range its vectors occupy, and public fear of a vector-borne Zika epidemic in the mainland United States is potentially informed by biased or limited scientific knowledge. With recent sexual transmission of the virus globally, we caution that our results only apply to the vector-borne transmission route of the pathogen, and while the threat of a mosquito-carried Zika pandemic may be overstated in the media, other transmission modes of the virus may emerge and facilitate naturalization worldwide.

The terrestrial reptile fauna of the Abrolhos Archipelago: species list and ecological aspects.

PubMed

Rocha, C F D; Dutra, G F; Vrcibradic, D; Menezes, V A

2002-05-01

We have studied the terrestrial reptile fauna of the Abrolhos Archipelago (a group of five islands located ca. 70 km off the southern coast of the State of Bahia, Brazil) and analyze here some of its ecological aspects such as diet, thermal ecology, activity, and some reproductive parameters. Three lizards comprise the archipelago's terrestrial reptile fauna: Tropidurus torquatus (Tropiduridae), Mabuya agilis (Scincidae), and Hemidactylus mabouia (Gekkonidae). The first two are diurnal and the latter is crepuscular/nocturnal (initiating activity at ca. 17:30). The activity period of T. torquatus extended from 5:30 to 18:30 h. Mean field body temperatures of active T. torquatus, M. agilis, and H. mabouia were, respectively, 34.0 +/- 3.7 degrees C (range 23.8-38.0 degrees C; N = 75), 34.5 +/- 2.2 degrees C (range 30.8-37.0 degrees C; N = 6), and 26.3 +/- 1.1 degrees C (range 24.8-28.0 degrees C; N = 8). The predominant prey items in the diet of T. torquatus were ants, coleopterans, and hemipterans. In the diet of M. agilis, coleopterans were the most frequent prey items. For H. mabouia, the most important dietary items were orthopterans. Clutch size of T. torquatus averaged 4.1 +/- 1.1 (range 2-6; N = 15) and was significantly related to female size (R2 = 0.618; p = 0.001; N = 15). Clutch size for H. mabouia was fixed (two) and mean litter size of the viviparous M. agilis was 3.3 +/- 0.6 (range 3-4; N = 3). Tropidurus torquatus and H. mabouia deposit their eggs under rocks in the study area, with the former burying them but not the latter; in both species, more than one female often oviposit under the same rock.

A study of risk factors associated with Newcastle disease epidemics in village free-range chickens in Uganda.

PubMed

Otim, M O; Kabagambe, E K; Mukiibi, G M; Christensen, H; Bisgaard, M

2007-01-01

A prospective study of risk factors associated with outbreaks of Newcastle disease (ND) in indigenous free-range chickens was carried out in three agro-ecological zones in eastern Uganda. Sixty households keeping chickens were randomly selected and studied from March 2004 to February 2005, covering rainy and dry seasons. Data on ND outbreaks, risk factors and flock dynamics were collected using an interviewer-administered questionnaire, while ND outbreaks were confirmed by haemagglutination inhibition test. Multivariate survival analyses were performed to identify the risk factors for Newcastle disease outbreaks. Although the survival time against ND was longer (> 100 days) in the dry compared to the rainy season, incidence in the two seasons was not significantly different (p > 0.05). None of the factors investigated was significantly associated with ND. However, purchasing of restocking chickens from the market and neighbourhood (hazard ratio [HR] = 1.79; 95% confidence interval [CI] 0.89-3.60), the presence of migratory wild birds (HR = 1.70; 95% CI 0.65-4.48) and being in agro-ecological zone 1 (HR = 1.48; 95% CI 0.66-3.36) showed a positive but non-significant association with risk for ND. To understand the roles of other domestic poultry species in the epidemiology of ND in rural free-range chickens, virus isolation and molecular characterization of isolates in addition to more prospective cohort studies with a larger sample size and similarly long period of follow-up are needed.

Global warming benefits the small in aquatic ecosystems.

PubMed

Daufresne, Martin; Lengfellner, Kathrin; Sommer, Ulrich

2009-08-04

Understanding the ecological impacts of climate change is a crucial challenge of the twenty-first century. There is a clear lack of general rules regarding the impacts of global warming on biota. Here, we present a metaanalysis of the effect of climate change on body size of ectothermic aquatic organisms (bacteria, phyto- and zooplankton, and fish) from the community to the individual level. Using long-term surveys, experimental data and published results, we show a significant increase in the proportion of small-sized species and young age classes and a decrease in size-at-age. These results are in accordance with the ecological rules dealing with the temperature-size relationships (i.e., Bergmann's rule, James' rule and Temperature-Size Rule). Our study provides evidence that reduced body size is the third universal ecological response to global warming in aquatic systems besides the shift of species ranges toward higher altitudes and latitudes and the seasonal shifts in life cycle events.

Modelling marine community responses to climate-driven species redistribution to guide monitoring and adaptive ecosystem-based management.

PubMed

Marzloff, Martin Pierre; Melbourne-Thomas, Jessica; Hamon, Katell G; Hoshino, Eriko; Jennings, Sarah; van Putten, Ingrid E; Pecl, Gretta T

2016-07-01

As a consequence of global climate-driven changes, marine ecosystems are experiencing polewards redistributions of species - or range shifts - across taxa and throughout latitudes worldwide. Research on these range shifts largely focuses on understanding and predicting changes in the distribution of individual species. The ecological effects of marine range shifts on ecosystem structure and functioning, as well as human coastal communities, can be large, yet remain difficult to anticipate and manage. Here, we use qualitative modelling of system feedback to understand the cumulative impacts of multiple species shifts in south-eastern Australia, a global hotspot for ocean warming. We identify range-shifting species that can induce trophic cascades and affect ecosystem dynamics and productivity, and evaluate the potential effectiveness of alternative management interventions to mitigate these impacts. Our results suggest that the negative ecological impacts of multiple simultaneous range shifts generally add up. Thus, implementing whole-of-ecosystem management strategies and regular monitoring of range-shifting species of ecological concern are necessary to effectively intervene against undesirable consequences of marine range shifts at the regional scale. Our study illustrates how modelling system feedback with only limited qualitative information about ecosystem structure and range-shifting species can predict ecological consequences of multiple co-occurring range shifts, guide ecosystem-based adaptation to climate change and help prioritise future research and monitoring. © 2016 John Wiley & Sons Ltd.

On the road: workable solutions to the problems of roads and highways

Treesearch

Mary M. Rowland

2004-01-01

Fourteen authors, ranging from transportation specialists to ecologists, have collaborated to write this very useful compendium describing the newly minted discipline of "road ecology." The authors state that road ecology "uses the science of ecology and landscape ecology to explore, understand, and address the interactions of roads and vehicles with...

Nutritional condition of elk in rocky mountain national park

USGS Publications Warehouse

Bender, L.C.; Cook, J.G.

2005-01-01

We tested the hypothesis that elk in Rocky Mountain National Park (RMNP) were at ecological carrying capacity by determining herd-specific levels of nutritional condition and fecundity. Ingesta-free body fat levels in adult cows that were lactating were 10.6% (s = 1.7; range = 6.2-15.4) and 7.7% (s = 0.5; range = 5.9-10.1) in November 2001 for the Horseshoe and Moraine Park herds, respectively. Cows that were not lactating were able to accrue significantly more body fat: 14.0% (s = 1.1; range = 7.7-19.3) and 11.5% (s = 0.8; range = 8.6-15.1) for the Horseshoe and Moraine Park herds, respectively. Cow elk lost most of their body fat over winter (April 2002 levels were 3.9% [s = 0.4] and 2.9% [s = 0.4] for the Horseshoe and Moraine Park herds, respectively). Nutritional condition indicated that both Horseshoe Park and Moraine Park elk were well below condition levels elk can achieve on very good-excellent nutrition (i.e., >15% body fat; Cook et al. 2004) and were comparable to other free-ranging elk populations. However, condition levels were higher than those expected at a "food-limited" carrying capacity, and a proportion of elk in each herd were able to achieve condition levels indicative of very good-excellent nutrition. Elk in RMNP are likely regulated and/or limited by a complex combination of density-independent (including significant heterogeneity in forage conditions across RMNP's landscape) and density-dependent processes, as condition levels contradict a simple density-dependent model of a population at ecological carrying capacity.

Spatial overlap in a solitary carnivore: support for the land tenure, kinship or resource dispersion hypotheses?

PubMed

Elbroch, L Mark; Lendrum, Patrick E; Quigley, Howard; Caragiulo, Anthony

2016-03-01

There are several alternative hypotheses about the effects of territoriality, kinship and prey availability on individual carnivore distributions within populations. The first is the land-tenure hypothesis, which predicts that carnivores regulate their density through territoriality and temporal avoidance. The second is the kinship hypothesis, which predicts related individuals will be clumped within populations, and the third is the resource dispersion hypothesis, which suggests that resource richness may explain variable sociality, spatial overlap or temporary aggregations of conspecifics. Research on the socio-spatial organization of animals is essential in understanding territoriality, intra- and interspecific competition, and contact rates that influence diverse ecology, including disease transmission between conspecifics and courtship behaviours. We explored these hypotheses with data collected on a solitary carnivore, the cougar (Puma concolor), from 2005 to 2012 in the Southern Yellowstone Ecosystem, Wyoming, USA. We employed 27 annual home ranges for 13 cougars to test whether home range overlap was better explained by land tenure, kinship, resource dispersion or some combination of the three. We found support for both the land tenure and resource dispersion hypotheses, but not for kinship. Cougar sex was the primary driver explaining variation in home range overlap. Males overlapped significantly with females, whereas the remaining dyads (F-F, M-M) overlapped significantly less. In support for the resource dispersion hypothesis, hunting opportunity (the probability of a cougar killing prey in a given location) was often higher in overlapping than in non-overlapping portions of cougar home ranges. In particular, winter hunt opportunity rather than summer hunt opportunity was higher in overlapping portions of female-female and male-female home ranges. Our results may indicate that solitary carnivores are more tolerant of sharing key resources with unrelated conspecifics than previously believed, or at least during periods of high resource availability. Further, our results suggest that the resource dispersion hypothesis, which is typically applied to social species, is applicable in describing the spatial organization of solitary carnivores. © 2015 The Authors. Journal of Animal Ecology © 2015 British Ecological Society.

[Land layout for lake tourism based on ecological restraint].

PubMed

Wang, Jian-Ying; Li, Jiang-Feng; Zou, Li-Lin; Liu, Shi-Bin

2012-10-01

To avoid the decrease and deterioration of lake wetlands and the other ecological issues such as lake water pollution that were caused by the unreasonable exploration of lake tourism, a land layout for the tourism development of Liangzi Lake with the priority of ecological security pattern was proposed, based on the minimal cumulative resistance model and by using GIS technology. The study area was divided into four ecological function zones, i. e., core protection zone, ecological buffer zone, ecotone zone, and human activity zone. The core protection zone was the landscape region of ecological source. In the protection zone, new tourism land was forbidden to be increased, and some of the existing fundamental tourism facilities should be removed while some of them should be upgraded. The ecological buffer zone was the landscape region with resistance value ranged from 0 to 4562. In the buffer zone, expansion of tourism land should be forbidden, the existing tourism land should be downsized, and human activities should be isolated from ecological source by converting the human environment to the natural environment as far as possible. The ecotone zone was the landscape region with resistance value ranged from 4562 to 30797. In this zone, the existing tourism land was distributed in patches, tourism land could be expanded properly, and the lake forestry ecological tourism should be developed widely. The human activity zone was the landscape region with resistance value ranged from 30797 to 97334, which would be the key area for the land layout of lake tourism. It was suggested that the land layout for tourism with the priority of landscape ecological security pattern would be the best choice for the lake sustainable development.

Ecological Sites of the Walnut Gulch Experimental Watershed

USDA-ARS?s Scientific Manuscript database

Soil and water conservation efforts on rangelands require a marriage of hydrologic and range management concepts. One important range management concept is that of an ecological site, which is defined by its ability to produce a plant community consisting of certain kinds, amounts, and proportions o...

Phenotypic clines, energy balances and ecological responses to climate change.

PubMed

Buckley, Lauren B; Nufio, César R; Kingsolver, Joel G

2014-01-01

The Metabolic Theory of Ecology has renewed interest in using energetics to scale across levels of ecological organization. Can scaling from individual phenotypes to population dynamics provides insight into why species have shifted their phenologies, abundances and distributions idiosyncratically in response to recent climate change? We consider how the energetic implications of phenotypes may scale to understand population and species level responses to climate change using four focal grasshopper species along an elevation gradient in Colorado. We use a biophysical model to translate phenotypes and environmental conditions into estimates of body temperatures. We measure thermal tolerances and preferences and metabolic rates to assess rates of energy use and acquisition. Body mass declines along the elevation gradient for all species, but mass-specific metabolic rates increases only modestly. We find interspecific differences in both overall thermal tolerances and preferences and in the variation of these metrics along the elevation gradient. The more dispersive species exhibit significantly higher thermal tolerance and preference consistent with much of their range spanning hot, low elevation areas. When integrating these metrics to consider metabolic constraints, we find that energetic costs decrease along the elevation gradient due to decreasing body size and temperature. Opportunities for energy acquisition, as reflected by the proportion of time that falls within a grasshopper's thermal tolerance range, peak at mid elevations. We discuss methods for translating these energetic metrics into population dynamics. Quantifying energy balances and allocation offers a viable approach for predicting how populations will respond to climate change and the consequences for species composed of populations that may be locally adapted. © 2013 The Authors. Journal of Animal Ecology © 2013 British Ecological Society.

Ocean acidification may aggravate social-ecological trade-offs in coastal fisheries.

PubMed

Voss, Rudi; Quaas, Martin F; Schmidt, Jörn O; Kapaun, Ute

2015-01-01

Ocean Acidification (OA) will influence marine ecosystems by changing species abundance and composition. Major effects are described for calcifying organisms, which are significantly impacted by decreasing pH values. Direct effects on commercially important fish are less well studied. The early life stages of fish populations often lack internal regulatory mechanisms to withstand the effects of abnormal pH. Negative effects can be expected on growth, survival, and recruitment success. Here we study Norwegian coastal cod, one of the few stocks where such a negative effect was experimentally quantified, and develop a framework for coupling experimental data on OA effects to ecological-economic fisheries models. In this paper, we scale the observed physiological responses to the population level by using the experimentally determined mortality rates as part of the stock-recruitment relationship. We then use an ecological-economic optimization model, to explore the potential effect of rising CO2 concentration on ecological (stock size), economic (profits), consumer-related (harvest) and social (employment) indicators, with scenarios ranging from present day conditions up to extreme acidification. Under the assumptions of our model, yields and profits could largely be maintained under moderate OA by adapting future fishing mortality (and related effort) to changes owing to altered pH. This adaptation comes at the costs of reduced stock size and employment, however. Explicitly visualizing these ecological, economic and social tradeoffs will help in defining realistic future objectives. Our results can be generalized to any stressor (or stressor combination), which is decreasing recruitment success. The main findings of an aggravation of trade-offs will remain valid. This seems to be of special relevance for coastal stocks with limited options for migration to avoid unfavorable future conditions and subsequently for coastal fisheries, which are often small scale local fisheries with limited operational ranges.

Ecological approach to resource survey and planning for environmentally significant Areas: The ABC method

NASA Astrophysics Data System (ADS)

Bastedo, Jamie D.; Nelson, J. Gordon; Theberge, John B.

1984-03-01

A resource survey and planning method for parks, reserves, and other environmentally significant areas (ESAs) is presented in the context of a holistic balanced approach to land use and environmental management. This method provides a framework for the acquisition, analysis, presentation, and application of diverse ecological data pertinent to land use planning and resource management within ESAs. Through the independent analysis and subsequent integration of abiotic, biotic, and cultural or ABC information, land areas within an ESA are identified in terms of their relative environmental significance and environmental constraints. The former term encompasses wildlife, historic, and other resource values, while the latter term reflects biophysical hazards and sensitivities, and land use conflicts. The method thus calls for a matching of an ESA's distinctive attributes with appropriate land use and institutional arrancements through an analysis of available acts, regulations, agencies, and other conservation and land use management mechanisms. The method culminates with a management proposal showing proposed park or reserve allocations, buffer areas, or other land use controls aimed at preserving an ESA's special ecological qualities, while providing for resource development. The authors suggest that all resource management decisions affecting ESA's should be governed by a philosophical stance that recognizes a spectrum of broad land use types, ranging from preservation to extractive use and rehabilitation.

Ecological niche transferability using invasive species as a case study.

PubMed

Fernández, Miguel; Hamilton, Healy

2015-01-01

Species distribution modeling is widely applied to predict invasive species distributions and species range shifts under climate change. Accurate predictions depend upon meeting the assumption that ecological niches are conserved, i.e., spatially or temporally transferable. Here we present a multi-taxon comparative analysis of niche conservatism using biological invasion events well documented in natural history museum collections. Our goal is to assess spatial transferability of the climatic niche of a range of noxious terrestrial invasive species using two complementary approaches. First we compare species' native versus invasive ranges in environmental space using two distinct methods, Principal Components Analysis and Mahalanobis distance. Second we compare species' native versus invaded ranges in geographic space as estimated using the species distribution modeling technique Maxent and the comparative index Hellinger's I. We find that species exhibit a range of responses, from almost complete transferability, in which the invaded niches completely overlap with the native niches, to a complete dissociation between native and invaded ranges. Intermediate responses included expansion of dimension attributable to either temperature or precipitation derived variables, as well as niche expansion in multiple dimensions. We conclude that the ecological niche in the native range is generally a poor predictor of invaded range and, by analogy, the ecological niche may be a poor predictor of range shifts under climate change. We suggest that assessing dimensions of niche transferability prior to standard species distribution modeling may improve the understanding of species' dynamics in the invaded range.

Toxins produced in cyanobacterial water blooms – toxicity and risks

PubMed Central

Bláha, Luděk; Babica, Pavel; Maršálek, Blahoslav

2009-01-01

Cyanobacterial blooms in freshwaters represent a major ecological and human health problem worldwide. This paper briefly summarizes information on major cyanobacterial toxins (hepatotoxins, neurotoxins etc.) with special attention to microcystins-cyclic heptapeptides with high acute and chronic toxicities. Besides discussion of human health risks, microcystin ecotoxicology and consequent ecological risks are also highlighted. Although significant research attention has been paid to microcystins, cyanobacteria produce a wide range of currently unknown toxins, which will require research attention. Further research should also address possible additive, synergistic or antagonistic effects among different classes of cyanobacterial metabolites, as well as interactions with other toxic stressors such as metals or persistent organic pollutants. PMID:21217843

Sexual behavior problems in preteen children: developmental, ecological, and behavioral correlates.

PubMed

Friedrich, W N; Davies, W Hobart; Feher, Eleonora; Wright, John

2003-06-01

A large sample of 2-12 year old children (N = 2311) was studied to determine the relationship between three sexually intrusive behavior items (SIBs) measured by the Child Sexual Behavior Inventory (CSBI) and a range of developmental, ecological, and behavioral correlates. The variables studied included age, gender, race, family income, single parent status, maternal education, family sexual behaviors, physical abuse, sexual abuse, domestic violence, social competence of the child, and three scales from the CBCL (Internalizing, Externalizing, and PTSD). Sexual abuse was not the primary predictor of SIB, but a model incorporating family adversity, modeling of coercive behavior, child behavior, and modeling of sexuality predicted a significant amount of variance.

Chapter 6: Breeding season ecology

Treesearch

Mark K. Sogge

2000-01-01

The willow flycatcher (Empidonax traillii) breeds across much of the conterminous United States and in portions of extreme southern Canada. As might be expected in such a wide-ranging species, willow flycatchers in different portions of the range exhibit differences in appearance, song, and ecological characteristics. The intent of this chapter is to...

Killer whale ecotypes: is there a global model?

PubMed

de Bruyn, P J N; Tosh, Cheryl A; Terauds, Aleks

2013-02-01

Killer whales, Orcinus orca, are top predators occupying key ecological roles in a variety of ecosystems and are one of the most widely distributed mammals on the planet. In consequence, there has been significant interest in understanding their basic biology and ecology. Long-term studies of Northern Hemisphere killer whales, particularly in the eastern North Pacific (ENP), have identified three ecologically distinct communities or ecotypes in that region. The success of these prominent ENP studies has led to similar efforts at clarifying the role of killer whale ecology in other regions, including Antarctica. In the Southern Hemisphere, killer whales present a range of behavioural, social and morphological characteristics to biologists, who often interpret this as evidence to categorize individuals or groups, and draw general ecological conclusions about these super-predators. Morphologically distinct forms (Type A, B, C, and D) occur in the Southern Ocean and studies of these different forms are often presented in conjunction with evidence for specialised ecology and behaviours. Here we review current knowledge of killer whale ecology and ecotyping globally and present a synthesis of existing knowledge. In particular, we highlight the complexity of killer whale ecology in the Southern Hemisphere and examine this in the context of comparatively well-studied Northern Hemisphere populations. We suggest that assigning erroneous or prefatory ecotypic status in the Southern Hemisphere could be detrimental to subsequent killer whale studies, because unsubstantiated characteristics may be assumed as a result of such classification. On this basis, we also recommend that ecotypic status classification for Southern Ocean killer whale morphotypes be reserved until more evidence-based ecological and taxonomic data are obtained. © 2012 The Authors. Biological Reviews © 2012 Cambridge Philosophical Society.

Ecological risk assessment of heavy metals in surface seawater and sediment near the outlet of a zinc factory in Huludao City, Liaoning Province, China

NASA Astrophysics Data System (ADS)

Feng, Yongliang; Chen, Yanzhen; Wang, Jing; Gong, Yufeng; Liu, Xigang; Mu, Gang; Tian, Hua

2016-11-01

At present, the methods widely applied to assess ecological risk of heavy metals are essentially single-point estimates in which exposure and toxicity data cannot be fully used and probabilities of adverse biological eff ects cannot be achieved. In this study, based on investigation of concentrations of six heavy metals (As, Hg, Pb, Cd, Cu, and Zn) in the surface seawater and sediment near the outlet of a zinc factory, located in Huludao City, Liaoning Province, China, a tiered approach consisting of several probabilistic options was used to refine ecological risk assessment for the individuals. A mixture of various heavy metals was detected in the surface seawater, and potential ecological risk index (PERI) was adopted to assess the potential ecological risk of heavy metals in the surface sediment. The results from all levels of aquatic ecological risk assessment in the tiered framework, ranging from comparison of single eff ects and exposure values to the use of distribution-based Hazard Quotient obtained through Monte Carlo simulation, are consistent with each other. Briefly, aquatic Zn and Cu posed a clear ecological risk, while Cd, Pb, Hg, and As in the water column posed potential risk. As expected, combined ecological risk of heavy metal mixture in the surface seawater was proved significantly higher than the risk caused by any individual heavy metal, calculated using the concept of total equivalent concentration. According to PERI, the severity of pollution by the six heavy metals in the surface sediment decreased in the following sequence: Cd>Hg>As>Pb>Cu>Zn, and the total heavy metals in the sediment posed a very high risk to the marine environment. This study provides a useful mathematical framework for ecological risk assessment of heavy metals.

Cuckoos host range is associated positively with distribution range and negatively with evolutionary uniqueness.

PubMed

Morelli, Federico; Benedetti, Yanina; Møller, Anders Pape; Liang, Wei; Carrascal, Luis M

2018-05-01

The evolutionary distinctiveness (ED) score is a measure of phylogenetic isolation that quantifies the evolutionary uniqueness of a species. Here, we compared the ED score of parasitic and non-parasitic cuckoo species world-wide, to understand whether parental care or parasitism represents the largest amount of phylogenetic uniqueness. Next, we focused only on 46 cuckoo species characterized by brood parasitism with a known number of host species, and we explored the associations among ED score, number of host species and breeding range size for these species. We assessed these associations using phylogenetic generalized least squares (PGLS) models, taking into account the phylogenetic signal. Parasitic cuckoo species were not more unique in terms of ED than non-parasitic species. However, we found a significant negative association between the evolutionary uniqueness and host range and a positive correlation between the number of host species and range size of parasitic cuckoos, probably suggesting a passive sampling of hosts by parasitic species as the breeding range broadens. The findings of this study showed that more generalist brood parasites occupied very different positions in a phylogenetic tree, suggesting that they have evolved independently within the Cuculiformes order. Finally, we demonstrated that specialist cuckoo species also represent the most evolutionarily unique species in the order of Cuculiformes. © 2018 The Authors. Journal of Animal Ecology © 2018 British Ecological Society.

Pollen dispersal slows geographical range shift and accelerates ecological niche shift under climate change

PubMed Central

Aguilée, Robin; Raoul, Gaël; Rousset, François; Ronce, Ophélie

2016-01-01

Species may survive climate change by migrating to track favorable climates and/or adapting to different climates. Several quantitative genetics models predict that species escaping extinction will change their geographical distribution while keeping the same ecological niche. We introduce pollen dispersal in these models, which affects gene flow but not directly colonization. We show that plant populations may escape extinction because of both spatial range and ecological niche shifts. Exact analytical formulas predict that increasing pollen dispersal distance slows the expected spatial range shift and accelerates the ecological niche shift. There is an optimal distance of pollen dispersal, which maximizes the sustainable rate of climate change. These conclusions hold in simulations relaxing several strong assumptions of our analytical model. Our results imply that, for plants with long distance of pollen dispersal, models assuming niche conservatism may not accurately predict their future distribution under climate change. PMID:27621443

Pollen dispersal slows geographical range shift and accelerates ecological niche shift under climate change.

PubMed

Aguilée, Robin; Raoul, Gaël; Rousset, François; Ronce, Ophélie

2016-09-27

Species may survive climate change by migrating to track favorable climates and/or adapting to different climates. Several quantitative genetics models predict that species escaping extinction will change their geographical distribution while keeping the same ecological niche. We introduce pollen dispersal in these models, which affects gene flow but not directly colonization. We show that plant populations may escape extinction because of both spatial range and ecological niche shifts. Exact analytical formulas predict that increasing pollen dispersal distance slows the expected spatial range shift and accelerates the ecological niche shift. There is an optimal distance of pollen dispersal, which maximizes the sustainable rate of climate change. These conclusions hold in simulations relaxing several strong assumptions of our analytical model. Our results imply that, for plants with long distance of pollen dispersal, models assuming niche conservatism may not accurately predict their future distribution under climate change.

Ecological significance of microsatellite variation in western North American populations of Bromus tectorum

Treesearch

Alisa P. Ramakrishnan; Susan Meyer; Daniel J. Fairbanks; Craig E. Coleman

2006-01-01

Bromus tectorum (cheatgrass or downy brome) is an exotic annual weed that is abundant in western USA. We examined variation in six microsatellite loci for 17 populations representing a range of habitats in Utah, Idaho, Nevada and Colorado (USA) and then intensively sampled four representative populations, for a total sample size of approximately 1000 individuals. All...

Current trends in the management of aspen and mixed aspen forests for sustainable production

Treesearch

A. J. David; John C. Zasada; D. W. Gilmore; S. M. Landhausser

2001-01-01

Quaking aspen (Populus tremuloides Michx.) is a remarkable species that performs several significant ecological roles throughout its range while at the same time is facing ever-increasing harvesting pressure. Although its full product potential remains untapped, aspen utilization has increased noticeably in the past 15 years as it has become a desired species for...

Large-scale patterns of forest fire occurrence in the Conterminous United States and Alaska, 2001-08

Treesearch

Kevin M. Potter

2012-01-01

Wildland fire represents an important ecological mechanism in many forest ecosystems. It shapes the distributions of species, maintains the structure and function of fire-prone communities, and is a significant evolutionary force (Bond and Keeley 2005). At the same time, fire outside the historic range of frequency and intensity can have extensive economic and...

Large-scale patterns of forest fire occurrence in the conterminous United States and Alaska, 2009

Treesearch

Kevin M. Potter

2013-01-01

Wildland fire represents an important ecological mechanism in many forest ecosystems. It shapes the distributions of species, maintains the structure and function of fire-prone communities, and is a significant evolutionary force (Bond and Keeley 2005). At the same time, fire outside the historic range of frequency and intensity can have extensive economic and...

2004 report on the health of Colorado's forests: Special issue: Ponderosa pine forests

Treesearch

Paige Lewis; Merrill R. Kaufmann; Laurie S. Huckaby; Dave Leatherman

2005-01-01

The 2004 Report on the Health of Colorado's Forests begins with an overview of significant incidents and trends in forest insect and disease activity across the state. The remainder of the Report provides an in-depth examination of the ecology, condition and management of Colorado's ponderosa pine forests. Unlike previous editions, which highlighted a range...

Systematic behavioural observation of executive performance after brain injury.

PubMed

Lewis, Mark W; Babbage, Duncan R; Leathem, Janet M

2017-01-01

To develop an ecologically valid measure of executive functioning (i.e. Planning and Organization, Executive Memory, Initiation, Cognitive Shifting, Impulsivity, Sustained and Directed Attention, Error Detection, Error Correction and Time Management) during a functional chocolate brownie cooking task. In Study 1, the inter-rater reliability of a novel behavioural observation assessment method was assessed with 10 people with traumatic brain injury (TBI). In Study 2, 27 people with TBI and 16 healthy controls completed the functional task along with other measures of executive functioning to assess validity. Intraclass correlation coefficients for six of the nine aspects of executive functioning ranged from .54 to 1.00. Percentage agreements for the remaining aspects ranged from 70% to 90%. Significant and non-significant, moderate, correlations were found between the functional cooking task and standard neuropsychological measures. The healthy control group performed better than the TBI group in six areas (d = 0.56 to 1.23). In this initial trial of a novel assessment method, adequate inter-rater reliability was found. The measure was associated with standard neuropsychological measures, and our healthy control group performed better than the TBI group. The measure appears to be an ecologically valid measure of executive functioning.

Ising universality describes emergent long-range synchronization of coupled ecological oscillators

NASA Astrophysics Data System (ADS)

Noble, Andrew

Understanding the synchronization of oscillations across space is fundamentally important to many scientific disciplines. In ecology, long-range synchronization of oscillations in spatial populations may elevate extinction risk and signal an impending catastrophe. The prevailing assumption is that synchronization on distances longer than the dispersal scale can only be due to environmental correlation. By contrast, recent work shows how scale-invariant synchronization can emerge from locally coupled population dynamics. In particular, we have found that the transition from incoherence to long-range synchronization of coupled ecological two-cycles is described by the Ising universality class. I will discuss evidence that an Ising critical point describes long-range correlations found in data on the individual yields of female pistachio trees in a large orchard. NSF INSPIRE Grant No. 1344187.

Century-scale Changes in Environmental Synchrony and Variability and their Effects on Populations of Birds and Reproduction of Trees

NASA Astrophysics Data System (ADS)

Koenig, W.

2016-12-01

The ecological impacts of modern global climate change are detectable in a wide variety of phenomena ranging from shifts in species ranges to changes in community composition and human disease dynamics. Thus far, however, little attention has been given to temporal changes in environmental spatial synchrony-the coincident change in abundance or value across the landscape-or environmental variability, despite the importance of these factors as drivers of population rescue and extinction and reproductive dynamics of both animal and plant populations. We quantified spatial synchrony of widespread North American wintering birds species using Audubon Christmas Bird Counts over the past 50 years and seed set variability (mast fruiting) among trees over the past century and found that both spatial synchrony of the birds and seed set variability have significantly increased over these time periods. The first of these results was mirrored by significant increases in spatial synchrony of mean maximum air temperature across North America, primarily during the summer, while the second is consistent with the hypothesis that climate change is resulting in greater seed set variability. These findings suggest the potential for temporal changes in envioronmental synchrony and variability to be affecting a wide range of ecological phenomena by influencing the probability of population rescue and extinction and by affecting ecosystem processes that rely on the resource pulses provided by mast fruiting plants.

Effect of dispersal at range edges on the structure of species ranges

USGS Publications Warehouse

Bahn, V.; O'Connor, R.J.; Krohn, W.B.

2006-01-01

Range edges are of particular interest to ecology because they hold key insights into the limits of the realized niche and associated population dynamics. A recent feature of Oikos summarized the state of the art on range edge ecology. While the typical question is what causes range edges, another important question is how range edges influence the distribution of abundances across a species geographic range when dispersal is present. We used a single species population dynamics model on a coupled-lattice to determine the effects of dispersal on peripheral populations as compared to populations at the core of the range. In the absence of resource gradients, the reduced neighborhood and thus lower connectivity or higher isolation among populations at the range edge alone led to significantly lower population sizes in the periphery of the range than in the core. Lower population sizes mean higher extinction risks and lower adaptability at the range edge, which could inhibit or slow range expansions, and thus effectively stabilize range edges. The strength of this effect depended on the potential population growth rate and the maximum dispersal distance. Lower potential population growth rates led to a stronger effect of dispersal resulting in a higher difference in population sizes between the two areas. The differential effect of dispersal on population sizes at the core and periphery of the range in the absence of resource gradients implies that traditional, habitat-based distribution models could result in misleading conclusions about the habitat quality in the periphery. Lower population sizes at the periphery are also relevant to conservation, because habitat removal not only eliminates populations but also creates new edges. Populations bordering these new edges may experience declines, due to their increased isolation. ?? OIKOS.

Pleistocene and ecological effects on continental-scale genetic differentiation in the bobcat (Lynx rufus).

PubMed

Reding, Dawn M; Bronikowski, Anne M; Johnson, Warren E; Clark, William R

2012-06-01

The potential for widespread, mobile species to exhibit genetic structure without clear geographic barriers is a topic of growing interest. Yet the patterns and mechanisms of structure--particularly over broad spatial scales--remain largely unexplored for these species. Bobcats occur across North America and possess many characteristics expected to promote gene flow. To test whether historical, topographic or ecological factors have influenced genetic differentiation in this species, we analysed 1 kb mtDNA sequence and 15 microsatellite loci from over 1700 samples collected across its range. The primary signature in both marker types involved a longitudinal cline with a sharp transition, or suture zone, occurring along the Great Plains. Thus, the data distinguished bobcats in the eastern USA from those in the western half, with no obvious physical barrier to gene flow. Demographic analyses supported a scenario of expansion from separate Pleistocene refugia, with the Great Plains representing a zone of secondary contact. Substructure within the two main lineages likely reflected founder effects, ecological factors, anthropogenic/topographic effects or a combination of these forces. Two prominent topographic features, the Mississippi River and Rocky Mountains, were not supported as significant genetic barriers. Ecological regions and environmental correlates explained a small but significant proportion of genetic variation. Overall, results implicate historical processes as the primary cause of broad-scale genetic differentiation, but contemporary forces seem to also play a role in promoting and maintaining structure. Despite the bobcat's mobility and broad niche, large-scale landscape changes have contributed to significant and complex patterns of genetic structure. © 2012 Blackwell Publishing Ltd.

Interspecific Differences in Metabolic Rate and Metabolic Temperature Sensitivity Create Distinct Thermal Ecological Niches in Lizards (Plestiodon)

PubMed Central

Watson, Charles M.; Burggren, Warren W.

2016-01-01

Three congeneric lizards from the southeastern United States (Plestiodon fasciatus, P. inexpectatus, and P. laticeps) exhibit a unique nested distribution. All three skink species inhabit the US Southeast, but two extend northward to central Ohio (P. fasciatus and P. laticeps) and P. fasciatus extends well into Canada. Distinct interspecific differences in microhabitat selection and behavior are associated with the cooler temperatures of the more Northern ranges. We hypothesized that interspecific differences in metabolic temperature sensitivity locally segregates them across their total range. Resting oxygen consumption was measured at 20°, 25° and 30°C. Plestiodon fasciatus, from the coolest habitats, exhibited greatly elevated oxygen consumption compared to the other species at high ecologically-relevant temperatures (0.10, 0.17 and 0.83 ml O2. g-1. h-1 at 20°, 25° and 30°C, respectively). Yet, P. inexpectatus, from the warmest habitats, exhibited sharply decreased oxygen consumption compared to the other species at lower ecologically-relevant temperatures (0.09, 0.27 and 0.42 ml O2. g-1. h-1 at 20°, 25° and 30°C, respectively). Plestiodon laticeps, from both open and closed microhabitats and intermediate latitudinal range, exhibited oxygen consumptions significantly lower than the other two species (0.057, 0.104 and 0.172 ml O2. g-1. h-1 at 20°, 25° and 30°C, respectively). Overall, Plestiodon showed metabolic temperature sensitivities (Q10s) in the range of 2–3 over the middle of each species’ normal temperature range. However, especially P. fasciatus and P. inexpectatus showed highly elevated Q10s (9 to 25) at the extreme ends of their temperature range. While morphologically similar, these skinks are metabolically distinct across the genus’ habitat, likely having contributed to their current distribution. PMID:27760215

Interspecific Differences in Metabolic Rate and Metabolic Temperature Sensitivity Create Distinct Thermal Ecological Niches in Lizards (Plestiodon).

PubMed

Watson, Charles M; Burggren, Warren W

2016-01-01

Three congeneric lizards from the southeastern United States (Plestiodon fasciatus, P. inexpectatus, and P. laticeps) exhibit a unique nested distribution. All three skink species inhabit the US Southeast, but two extend northward to central Ohio (P. fasciatus and P. laticeps) and P. fasciatus extends well into Canada. Distinct interspecific differences in microhabitat selection and behavior are associated with the cooler temperatures of the more Northern ranges. We hypothesized that interspecific differences in metabolic temperature sensitivity locally segregates them across their total range. Resting oxygen consumption was measured at 20°, 25° and 30°C. Plestiodon fasciatus, from the coolest habitats, exhibited greatly elevated oxygen consumption compared to the other species at high ecologically-relevant temperatures (0.10, 0.17 and 0.83 ml O2. g-1. h-1 at 20°, 25° and 30°C, respectively). Yet, P. inexpectatus, from the warmest habitats, exhibited sharply decreased oxygen consumption compared to the other species at lower ecologically-relevant temperatures (0.09, 0.27 and 0.42 ml O2. g-1. h-1 at 20°, 25° and 30°C, respectively). Plestiodon laticeps, from both open and closed microhabitats and intermediate latitudinal range, exhibited oxygen consumptions significantly lower than the other two species (0.057, 0.104 and 0.172 ml O2. g-1. h-1 at 20°, 25° and 30°C, respectively). Overall, Plestiodon showed metabolic temperature sensitivities (Q10s) in the range of 2-3 over the middle of each species' normal temperature range. However, especially P. fasciatus and P. inexpectatus showed highly elevated Q10s (9 to 25) at the extreme ends of their temperature range. While morphologically similar, these skinks are metabolically distinct across the genus' habitat, likely having contributed to their current distribution.

Potential Biological and Ecological Effects of Flickering Artificial Light

PubMed Central

Inger, Richard; Bennie, Jonathan; Davies, Thomas W.; Gaston, Kevin J.

2014-01-01

Organisms have evolved under stable natural lighting regimes, employing cues from these to govern key ecological processes. However, the extent and density of artificial lighting within the environment has increased recently, causing widespread alteration of these regimes. Indeed, night-time electric lighting is known significantly to disrupt phenology, behaviour, and reproductive success, and thence community composition and ecosystem functioning. Until now, most attention has focussed on effects of the occurrence, timing, and spectral composition of artificial lighting. Little considered is that many types of lamp do not produce a constant stream of light but a series of pulses. This flickering light has been shown to have detrimental effects in humans and other species. Whether a species is likely to be affected will largely be determined by its visual temporal resolution, measured as the critical fusion frequency. That is the frequency at which a series of light pulses are perceived as a constant stream. Here we use the largest collation to date of critical fusion frequencies, across a broad range of taxa, to demonstrate that a significant proportion of species can detect such flicker in widely used lamps. Flickering artificial light thus has marked potential to produce ecological effects that have not previously been considered. PMID:24874801

Population ecology of the sea lamprey (Petromyzon marinus) as an invasive species in the Laurentian Great Lakes and an imperiled species in Europe

USGS Publications Warehouse

Hansen, Michael J.; Madenjian, Charles P.; Slade, Jeffrey W.; Steeves, Todd B.; Almeida, Pedro R.; Quintella, Bernardo R.

2016-01-01

The sea lamprey Petromyzon marinus (Linnaeus) is both an invasive non-native species in the Laurentian Great Lakes of North America and an imperiled species in much of its native range in North America and Europe. To compare and contrast how understanding of population ecology is useful for control programs in the Great Lakes and restoration programs in Europe, we review current understanding of the population ecology of the sea lamprey in its native and introduced range. Some attributes of sea lamprey population ecology are particularly useful for both control programs in the Great Lakes and restoration programs in the native range. First, traps within fish ladders are beneficial for removing sea lampreys in Great Lakes streams and passing sea lampreys in the native range. Second, attractants and repellants are suitable for luring sea lampreys into traps for control in the Great Lakes and guiding sea lamprey passage for conservation in the native range. Third, assessment methods used for targeting sea lamprey control in the Great Lakes are useful for targeting habitat protection in the native range. Last, assessment methods used to quantify numbers of all life stages of sea lampreys would be appropriate for measuring success of control in the Great Lakes and success of conservation in the native range.

Using expert informed GIS to locate important marine social-ecological hotspots.

PubMed

Mahboubi, Pouyan; Parkes, Margot; Stephen, Craig; Chan, Hing Man

2015-09-01

The marine environment provides significant benefits to many local communities. Pressure to develop coastal waterways worldwide creates an urgent need for tools to locate marine spaces that have important social or ecological values, and to quantify their relative importance. The primary objective of this study was to develop, apply and critically assess a tool to identify important social-ecological hotspots in the marine environment. The study was conducted in a typical coastal community in northern British Columbia, Canada. This expert-informed GIS, or xGIS, tool used a survey instrument to draw on the knowledge of local experts from a range of backgrounds with respect to a series of 12 social-ecological value attributes, such as biodiversity, cultural and economic values. We identified approximately 1500 polygons on marine maps and assigned relative values to them using a token distribution exercise. A series of spatial statistical analyses were performed to locate and quantify the relative social-ecological importance of marine spaces and the results were ultimately summarized in a single hotspot map of the entire study area. This study demonstrates the utility of xGIS as a useful tool for stakeholders and environmental managers engaged in the planning and management of marine resources at the local and regional levels. Copyright © 2015 Elsevier Ltd. All rights reserved.

Ecological and human health risks arising from exposure to metals in urban soils under different land use in Nigeria.

PubMed

Iwegbue, Chukwujindu M A; Martincigh, Bice S

2018-05-01

The concentrations of eight metals (Cd, Pb, Cr, Ni, Cu, Mn, Zn and Fe) were measured in soils under different land use in an urban environment of the Niger Delta in Nigeria. The aim was to provide information on the potential ecological and human health risks associated with human exposure to metals in these soils. The potential ecological risk due to metals in soils of these land use types falls in the range of low to moderate ecological risk with a significant contribution from Cd. The severity of the individual metals to ecological risk in these land use types followed the order Cd > Pb > Zn > Cu > Ni > Cr > Mn. The non-carcinogenic risk, expressed in terms of the hazard index (HI), arising through exposure to metals through oral, dermal and inhalation pathways, was greater than 1 for children in the majority of the land use types and less than 1 for adults for all land use types. This indicated that there are considerable non-cancer risks arising from childhood exposure to metals in soils of these land use types. The cancer risk values were within acceptable threshold values indicating a negligible cancer risk for both children and adults exposed to metals in these urban soils.

Sedimentology, geochemistry, pollution status and ecological risk assessment of some heavy metals in surficial sediments of an Egyptian lagoon connecting to the Mediterranean Sea.

PubMed

El-Said, Ghada F; Draz, Suzanne E O; El-Sadaawy, Manal M; Moneer, Abeer A

2014-01-01

Spatial distribution of heavy metals (Co, Cu, Ni, Cr, Mn, Zn and Fe) was studied on Lake Edku's surface sediments in relation to sedimentology and geochemistry characteristics and their contamination status on the ecological system. Lake Edku's sediments were dominated by sandy silt and silty sand textures and were enriched with carbonate content (9.83-58.46%). Iron and manganese were the most abundant heavy metals with ranges of 1.69 to 8.06 mg g(-1) and 0.88 to 3.27 mg g(-1), respectively. Cobalt and nickel showed a harmonic distribution along the studied sediments. The results were interpreted by the statistical means. The heavy metal pollution status and their ecological risk in Lake Edku was evaluated using the sediment quality guidelines and the contamination assessment methods (geoaccumulation, pollution load and potential ecological risk indices, enrichment factor, contamination degree as well as effect range median (ERM) and probable effect level (PEL) quotients). Amongst the determined heavy metals, zinc had the most ecological risk. Overall, the heavy metals in surface sediments showed ecological effect range from moderate to considerable risk, specially, in the stations in front of the seawater and in drain sources that had the highest toxic priority.

IF ECOLOGICAL RISK ASSESSMENT IS THE ANSWER, WHAT IS THE QUESTION?

EPA Science Inventory

Ecological risk assessment has become a commonly used tool in policy analysis, but its use is controversial. Opinions are diverse; they range from enthusiastic support to caustic dismissal. Much of the controversy with using risk assessment in ecological policy analysis revolves ...

Why Does Rhinopithecus bieti Prefer the Highest Elevation Range in Winter? A Test of the Sunshine Hypothesis

PubMed Central

Behm, Jocelyn E.; Wang, Lin; Huang, Yong; Long, Yongcheng; Zhu, Jianguo

2011-01-01

Environmental factors that affect spatiotemporal distribution patterns of animals usually include resource availability, temperature, and the risk of predation. However, they do not explain the counterintuitive preference of high elevation range in winter by the black-and-white snub-nosed monkey (Rhinopithecus bieti). We asked whether variation of sunshine along with elevations is the key driving force. To test this hypothesis, we conducted field surveys to demonstrate that there was a statistically significant pattern of high elevation use during winter. We then asked whether this pattern can be explained by certain environmental factors, namely temperature, sunshine duration and solar radiation. Finally, we concluded with a possible ecological mechanism for this pattern. In this study, we employed GIS technology to quantify solar radiation and sunshine duration across the monkey's range. Our results showed that: 1) R. bieti used the high altitude range between 4100–4400 m in winter although the yearly home range spanned from 3500–4500 m; 2) both solar radiation and sunshine duration increased with elevation while temperature decreased with elevation; 3) within the winter range, the use of range was significantly correlated with solar radiation and sunshine duration; 4) monkeys moved to the areas with high solar radiation and duration following a snowfall, where the snow melts faster and food is exposed earlier. We concluded that sunshine was the main factor that influences selection of high elevation habitat for R. bieti in winter. Since some other endotherms in the area exhibit similar winter distributional patterns, we developed a sunshine hypothesis to explain this phenomenon. In addition, our work also represented a new method of integrating GIS models into traditional field ecology research to study spatiotemporal distribution pattern of wildlife. We suggest that further theoretical and empirical studies are necessary for better understanding of sunshine influence on wildlife range use. PMID:21915329

Reproductive system, social organization, human disturbance and ecological dominance in native populations of the little fire ant, Wasmannia auropunctata.

PubMed

Foucaud, Julien; Orivel, Jérôme; Fournier, Denis; Delabie, Jacques H C; Loiseau, Anne; Le Breton, Julien; Cerdan, Philippe; Estoup, Arnaud

2009-12-01

The invasive ant species Wasmannia auropunctata displays both ecologically dominant and non-dominant populations within its native range. Three factors could theoretically explain the ecological dominance of some native populations of W. auropunctata: (i) its clonal reproductive system, through demographic and/or adaptive advantages; (ii) its unicolonial social organization, through lower intraspecific and efficient interspecific competition; (iii) the human disturbance of its native range, through the modification of biotic and abiotic environmental conditions. We used microsatellite markers and behavioural tests to uncover the reproductive modes and social organization of dominant and non-dominant native populations in natural and human-modified habitats. Microsatellite and mtDNA data indicated that dominant and non-dominant native populations (supercolonies as determined by aggression tests) of W. auropunctata did not belong to different evolutionary units. We found that the reproductive system and the social organization are neither necessary nor sufficient to explain W. auropunctata ecological dominance. Dominance rather seems to be set off by unknown ecological factors altered by human activities, as all dominant populations were recorded in human-modified habitats. The clonal reproductive system found in some populations of W. auropunctata may however indirectly contribute to its ecological dominance by allowing the species to expand its environmental niche, through the fixation over time of specific combinations of divergent male and female genotypes. Unicoloniality may rather promote the range expansion of already dominant populations than actually trigger ecological dominance. The W. auropunctata model illustrates the strong impact of human disturbance on species' ecological features and the adaptive potential of clonal reproductive systems.

Relationships fade with time: a meta-analysis of temporal trends in publication in ecology and evolution.

PubMed Central

Jennions, Michael D; Møller, Anders P

2002-01-01

Both significant positive and negative relationships between the magnitude of research findings (their 'effect size') and their year of publication have been reported in a few areas of biology. These trends have been attributed to Kuhnian paradigm shifts, scientific fads and bias in the choice of study systems. Here we test whether or not these isolated cases reflect a more general trend. We examined the relationship using effect sizes extracted from 44 peer-reviewed meta-analyses covering a wide range of topics in ecological and evolutionary biology. On average, there was a small but significant decline in effect size with year of publication. For the original empirical studies there was also a significant decrease in effect size as sample size increased. However, the effect of year of publication remained even after we controlled for sampling effort. Although these results have several possible explanations, it is suggested that a publication bias against non-significant or weaker findings offers the most parsimonious explanation. As in the medical sciences, non-significant results may take longer to publish and studies with both small sample sizes and non-significant results may be less likely to be published. PMID:11788035

Metabolic costs imposed by hydrostatic pressure constrain bathymetric range in the lithodid crab Lithodes maja.

PubMed

Brown, Alastair; Thatje, Sven; Morris, James P; Oliphant, Andrew; Morgan, Elizabeth A; Hauton, Chris; Jones, Daniel O B; Pond, David W

2017-11-01

The changing climate is shifting the distributions of marine species, yet the potential for shifts in depth distributions is virtually unexplored. Hydrostatic pressure is proposed to contribute to a physiological bottleneck constraining depth range extension in shallow-water taxa. However, bathymetric limitation by hydrostatic pressure remains undemonstrated, and the mechanism limiting hyperbaric tolerance remains hypothetical. Here, we assess the effects of hydrostatic pressure in the lithodid crab Lithodes maja (bathymetric range 4-790 m depth, approximately equivalent to 0.1 to 7.9 MPa hydrostatic pressure). Heart rate decreased with increasing hydrostatic pressure, and was significantly lower at ≥10.0 MPa than at 0.1 MPa. Oxygen consumption increased with increasing hydrostatic pressure to 12.5 MPa, before decreasing as hydrostatic pressure increased to 20.0 MPa; oxygen consumption was significantly higher at 7.5-17.5 MPa than at 0.1 MPa. Increases in expression of genes associated with neurotransmission, metabolism and stress were observed between 7.5 and 12.5 MPa. We suggest that hyperbaric tolerance in L maja may be oxygen-limited by hyperbaric effects on heart rate and metabolic rate, but that L maja 's bathymetric range is limited by metabolic costs imposed by the effects of high hydrostatic pressure. These results advocate including hydrostatic pressure in a complex model of environmental tolerance, where energy limitation constrains biogeographic range, and facilitate the incorporation of hydrostatic pressure into the broader metabolic framework for ecology and evolution. Such an approach is crucial for accurately projecting biogeographic responses to changing climate, and for understanding the ecology and evolution of life at depth. © 2017. Published by The Company of Biologists Ltd.

Improving the interpretability of climate landscape metrics: An ecological risk analysis of Japan's Marine Protected Areas.

PubMed

García Molinos, Jorge; Takao, Shintaro; Kumagai, Naoki H; Poloczanska, Elvira S; Burrows, Michael T; Fujii, Masahiko; Yamano, Hiroya

2017-10-01

Conservation efforts strive to protect significant swaths of terrestrial, freshwater and marine ecosystems from a range of threats. As climate change becomes an increasing concern, these efforts must take into account how resilient-protected spaces will be in the face of future drivers of change such as warming temperatures. Climate landscape metrics, which signal the spatial magnitude and direction of climate change, support a convenient initial assessment of potential threats to and opportunities within ecosystems to inform conservation and policy efforts where biological data are not available. However, inference of risk from purely physical climatic changes is difficult unless set in a meaningful ecological context. Here, we aim to establish this context using historical climatic variability, as a proxy for local adaptation by resident biota, to identify areas where current local climate conditions will remain extant and future regional climate analogues will emerge. This information is then related to the processes governing species' climate-driven range edge dynamics, differentiating changes in local climate conditions as promoters of species range contractions from those in neighbouring locations facilitating range expansions. We applied this approach to assess the future climatic stability and connectivity of Japanese waters and its network of marine protected areas (MPAs). We find 88% of Japanese waters transitioning to climates outside their historical variability bounds by 2035, resulting in large reductions in the amount of available climatic space potentially promoting widespread range contractions and expansions. Areas of high connectivity, where shifting climates converge, are present along sections of the coast facilitated by the strong latitudinal gradient of the Japanese archipelago and its ocean current system. While these areas overlap significantly with areas currently under significant anthropogenic pressures, they also include much of the MPA network that may provide stepping-stone protection for species that must shift their distribution because of climate change. © 2017 John Wiley & Sons Ltd.

[Selectivity and tolerance of sea urchin (Hemicentrotus pulcherrimus) to environmental change].

PubMed

You, Kai; Zeng, Xiaoqi; Liu, Hui; Zhang, Xiumei; Liu, Qun

2003-03-01

An experimental ecological study of sea urchin (Hemicentrotus pulcherrimus) sampled from coastal waters of Qingdao was focused on the fundamental ecological factors such as temperature, salinity, light intensity and substratum. The results showed that the suitable ecological range of temperature was from 8 degrees C to 22 degrees C, and the selectivity to temperature was changed with the previous living temperatures. Hemicentrotus pulcherrimus was a kind of stenohaline creature. Its optimum ecological range of salinity was from 30 to 35. The results also showed that Hemicentrotus pulcherrimus liked to select weak light environment (< 50 lux), especially under non-food condition. Hemicentrotus pulcherrimus had the positive substratum-selectivity to coarse sand and the negative substratum-selectivity to silver sand.

Stomatal vs. genome size in angiosperms: the somatic tail wagging the genomic dog?

PubMed Central

Hodgson, J. G.; Sharafi, M.; Jalili, A.; Díaz, S.; Montserrat-Martí, G.; Palmer, C.; Cerabolini, B.; Pierce, S.; Hamzehee, B.; Asri, Y.; Jamzad, Z.; Wilson, P.; Raven, J. A.; Band, S. R.; Basconcelo, S.; Bogard, A.; Carter, G.; Charles, M.; Castro-Díez, P.; Cornelissen, J. H. C.; Funes, G.; Jones, G.; Khoshnevis, M.; Pérez-Harguindeguy, N.; Pérez-Rontomé, M. C.; Shirvany, F. A.; Vendramini, F.; Yazdani, S.; Abbas-Azimi, R.; Boustani, S.; Dehghan, M.; Guerrero-Campo, J.; Hynd, A.; Kowsary, E.; Kazemi-Saeed, F.; Siavash, B.; Villar-Salvador, P.; Craigie, R.; Naqinezhad, A.; Romo-Díez, A.; de Torres Espuny, L.; Simmons, E.

2010-01-01

Background and Aims Genome size is a function, and the product, of cell volume. As such it is contingent on ecological circumstance. The nature of ‘this ecological circumstance’ is, however, hotly debated. Here, we investigate for angiosperms whether stomatal size may be this ‘missing link’: the primary determinant of genome size. Stomata are crucial for photosynthesis and their size affects functional efficiency. Methods Stomatal and leaf characteristics were measured for 1442 species from Argentina, Iran, Spain and the UK and, using PCA, some emergent ecological and taxonomic patterns identified. Subsequently, an assessment of the relationship between genome-size values obtained from the Plant DNA C-values database and measurements of stomatal size was carried out. Key Results Stomatal size is an ecologically important attribute. It varies with life-history (woody species < herbaceous species < vernal geophytes) and contributes to ecologically and physiologically important axes of leaf specialization. Moreover, it is positively correlated with genome size across a wide range of major taxa. Conclusions Stomatal size predicts genome size within angiosperms. Correlation is not, however, proof of causality and here our interpretation is hampered by unexpected deficiencies in the scientific literature. Firstly, there are discrepancies between our own observations and established ideas about the ecological significance of stomatal size; very large stomata, theoretically facilitating photosynthesis in deep shade, were, in this study (and in other studies), primarily associated with vernal geophytes of unshaded habitats. Secondly, the lower size limit at which stomata can function efficiently, and the ecological circumstances under which these minute stomata might occur, have not been satisfactorally resolved. Thus, our hypothesis, that the optimization of stomatal size for functional efficiency is a major ecological determinant of genome size, remains unproven. PMID:20375204

Isolation of Polyvalent Bacteriophages by Sequential Multiple-Host Approaches

PubMed Central

Yu, Pingfeng; Li, Mengyan; Dai, Zhaoyi; Alvarez, Pedro J. J.

2015-01-01

Many studies on phage biology are based on isolation methods that may inadvertently select for narrow-host-range phages. Consequently, broad-host-range phages, whose ecological significance is largely unexplored, are consistently overlooked. To enhance research on such polyvalent phages, we developed two sequential multihost isolation methods and tested both culture-dependent and culture-independent phage libraries for broad infectivity. Lytic phages isolated from activated sludge were capable of interspecies or even interorder infectivity without a significant reduction in the efficiency of plating (0.45 to 1.15). Two polyvalent phages (PX1 of the Podoviridae family and PEf1 of the Siphoviridae family) were characterized in terms of adsorption rate (3.54 × 10−10 to 8.53 × 10−10 ml/min), latent time (40 to 55 min), and burst size (45 to 99 PFU/cell), using different hosts. These phages were enriched with a nonpathogenic host (Pseudomonas putida F1 or Escherichia coli K-12) and subsequently used to infect model problematic bacteria. By using a multiplicity of infection of 10 in bacterial challenge tests, >60% lethality was observed for Pseudomonas aeruginosa relative to uninfected controls. The corresponding lethality for Pseudomonas syringae was ∼50%. Overall, this work suggests that polyvalent phages may be readily isolated from the environment by using different sequential hosts, and this approach should facilitate the study of their ecological significance as well as enable novel applications. PMID:26590277

A Comparison of Scientists' Arguments and School Argumentation Tasks

ERIC Educational Resources Information Center

MacPherson, Anna C.

2016-01-01

This study sought to investigate the arguments that ecologists engage in as part of their work and to compare their arguments with the way in which ecological arguments have been presented in school argumentation tasks. Ten ecologists, in subfields ranging from individual/behavioral ecology to global ecology, participated in semistructured…

Inter-generational change in African elephant range use is associated with poaching risk, primary productivity and adult mortality.

PubMed

Goldenberg, Shifra Z; Douglas-Hamilton, Iain; Wittemyer, George

2018-05-30

Repeated use of the same areas may benefit animals as they exploit familiar sites, leading to consistent home ranges over time that can span generations. Changing risk landscapes may reduce benefits associated with home range fidelity, however, and philopatric animals may alter movement in response to new pressures. Despite the importance of range changes to ecological and evolutionary processes, little tracking data have been collected over the long-term nor has range change been recorded in response to human pressures across generations. Here, we investigate the relationships between ecological, demographic and human variables and elephant ranging behaviour across generations using 16 years of tracking data from nine distinct female social groups in a population of elephants in northern Kenya that was heavily affected by ivory poaching during the latter half of the study. Nearly all groups-including those that did not experience loss of mature adults-exhibited a shift north over time, apparently in response to increased poaching in the southern extent of the study area. However, loss of mature adults appeared to be the primary indicator of range shifts and expansions, as generational turnover was a significant predictor of range size increases and range centroid shifts. Range expansions and northward shifts were associated with higher primary productivity and lower poached carcass densities, while westward shifts exhibited a trend to areas with higher values of primary productivity and higher poached carcass densities relative to former ranges. Together these results suggest a trade-off between resource access, mobility and safety. We discuss the relevance of these results to elephant conservation efforts and directions meriting further exploration in this disrupted society of a keystone species. © 2018 The Author(s).

Communal range defence in primates as a public goods dilemma.

PubMed

Willems, Erik P; Arseneau, T Jean M; Schleuning, Xenia; van Schaik, Carel P

2015-12-05

Classic socio-ecological theory holds that the occurrence of aggressive range defence is primarily driven by ecological incentives, most notably by the economic defendability of an area or the resources it contains. While this ecological cost-benefit framework has great explanatory power in solitary or pair-living species, comparative work on group-living primates has always found economic defendability to be a necessary, but not sufficient condition to account for the distribution of effective range defence across the taxon. This mismatch between theory and observation has recently been ascribed to a collective action problem among group members in, what is more informatively viewed as, a public goods dilemma: mounting effective defence of a communal range against intrusions by outgroup conspecifics. We here further develop this framework, and report on analyses at three levels of biological organization: across species, across populations within a single lineage and across groups and individuals within a single population. We find that communal range defence in primates very rarely involves collective action sensu stricto and that it is best interpreted as the outcome of opportunistic and strategic individual-level decisions. Whether the public good of a defended communal range is produced by solitary, joint or collective action is thus the outcome of the interplay between the unique characteristics of each individual, local and current socio-ecological conditions, and fundamental life-history traits of the species. © 2015 The Author(s).

Communal range defence in primates as a public goods dilemma

PubMed Central

Willems, Erik P.; Arseneau, T. Jean. M.; Schleuning, Xenia; van Schaik, Carel P.

2015-01-01

Classic socio-ecological theory holds that the occurrence of aggressive range defence is primarily driven by ecological incentives, most notably by the economic defendability of an area or the resources it contains. While this ecological cost–benefit framework has great explanatory power in solitary or pair-living species, comparative work on group-living primates has always found economic defendability to be a necessary, but not sufficient condition to account for the distribution of effective range defence across the taxon. This mismatch between theory and observation has recently been ascribed to a collective action problem among group members in, what is more informatively viewed as, a public goods dilemma: mounting effective defence of a communal range against intrusions by outgroup conspecifics. We here further develop this framework, and report on analyses at three levels of biological organization: across species, across populations within a single lineage and across groups and individuals within a single population. We find that communal range defence in primates very rarely involves collective action sensu stricto and that it is best interpreted as the outcome of opportunistic and strategic individual-level decisions. Whether the public good of a defended communal range is produced by solitary, joint or collective action is thus the outcome of the interplay between the unique characteristics of each individual, local and current socio-ecological conditions, and fundamental life-history traits of the species. PMID:26503678

Ecological risk assessment of trace metal accumulation in sediments of Veraval Harbor, Gujarat, Arabian Sea.

PubMed

Sundararajan, S; Khadanga, Mukunda Kesari; Kumar, J Prince Prakash Jeba; Raghumaran, S; Vijaya, R; Jena, Basanta Kumar

2017-01-15

In this study, different types of indices were used to assess the ecological risk of trace metal contamination in sediments on the basis of sediment quality guidelines at Veraval Fishery Harbor. Sediment samples were collected from three sectors in pre-, post-, and monsoon seasons in 2006. Trace metal concentrations were higher in the inner sector during post-monsoon, and it showed the highest statistical significance (p<0.01) among the stations. Pollution load index was higher than unity, indicating alternation by effluent discharge from industries. Enrichment factor and geo-accumulation index showed that Cd, Pb, and Zn were enriched in the northern part of the harbor and Pb had accumulated in the harbor sediment. The ecological risk assessment index revealed that Ni, Zn, and Pb were higher than the effect range median values, indicating their potential toxicity to the aquatic environment in the Veraval Harbor. Hence, the harbor is dominated by anthropogenic activities rather than natural process. Copyright © 2016 Elsevier Ltd. All rights reserved.

"The Whole Family Suffered, so the Whole Family Needs to Recover": Thematic Analysis of Substance-Abusing Mothers' Family Therapy Sessions.

PubMed

Brakenhoff, Brittany; Slesnick, Natasha

2015-03-01

Substance abusing mothers and their children are more likely to experience a range of social, behavioral, and psychological difficulties. Despite the significant challenges faced by these families, little is known about their experiences in treatment. The current study analyzed 12 sessions of family therapy using thematic analysis to identify common themes that arose during substance abusing mothers and their children's discussion during family therapy. Mothers' ages ranged from 28 to 35 years and the children's ages ranged from 12 to 14 years. Four therapy sessions from three families were coded for a total of 12 therapy sessions. An ecological framework was used to classify themes, in which themes related to each level of the families' ecological systems were identified. Thematic analysis of the therapy sessions indicated that mothers and their children primarily discussed topics related to their relational and emotional needs. The findings indicated that substance use disordered mothers and their children have unique treatment needs that should be addressed when the mother seeks treatment. More research is needed to further clarify and confirm the observations in this study. In particular, future research should include a larger sample and quantitative methodology.

Genetic Diversity and Ecological Niche Modelling of Wild Barley: Refugia, Large-Scale Post-LGM Range Expansion and Limited Mid-Future Climate Threats?

PubMed Central

Russell, Joanne; van Zonneveld, Maarten; Dawson, Ian K.; Booth, Allan; Waugh, Robbie; Steffenson, Brian

2014-01-01

Describing genetic diversity in wild barley (Hordeum vulgare ssp. spontaneum) in geographic and environmental space in the context of current, past and potential future climates is important for conservation and for breeding the domesticated crop (Hordeum vulgare ssp. vulgare). Spatial genetic diversity in wild barley was revealed by both nuclear- (2,505 SNP, 24 nSSR) and chloroplast-derived (5 cpSSR) markers in 256 widely-sampled geo-referenced accessions. Results were compared with MaxEnt-modelled geographic distributions under current, past (Last Glacial Maximum, LGM) and mid-term future (anthropogenic scenario A2, the 2080s) climates. Comparisons suggest large-scale post-LGM range expansion in Central Asia and relatively small, but statistically significant, reductions in range-wide genetic diversity under future climate. Our analyses support the utility of ecological niche modelling for locating genetic diversity hotspots and determine priority geographic areas for wild barley conservation under anthropogenic climate change. Similar research on other cereal crop progenitors could play an important role in tailoring conservation and crop improvement strategies to support future human food security. PMID:24505252

Ecological differentiation of diploid and polyploid cytotypes of Senecio carniolicus sensu lato (Asteraceae) is stronger in areas of sympatry.

PubMed

Sonnleitner, Michaela; Hülber, Karl; Flatscher, Ruth; Escobar García, Pedro; Winkler, Manuela; Suda, Jan; Schönswetter, Peter; Schneeweiss, Gerald M

2016-02-01

Ecological differentiation is recognized as an important factor for polyploid speciation, but little is known regarding whether the ecological niches of cytotypes differ between areas of sympatry and areas where single cytotypes occur (i.e. niche displacement). Ecological niches of four groups of Senecio carniolicus sensu lato (s.l.) (western and eastern diploid lineages, tetraploids and hexaploids) were characterized via Landolt indicator values of the accompanying vascular plant species and tested using multivariate and univariate statistics. The four groups of S. carniolicus s.l. were ecologically differentiated mainly with respect to temperature, light and soil (humus content, nutrients, moisture variability). Niche breadths did not differ significantly. In areas of sympatry hexaploids shifted towards sites with higher temperature, less light and higher soil humus content as compared with homoploid sites, whereas diploids and tetraploids shifted in the opposite direction. In heteroploid sites of tetraploids and the western diploid lineage the latter shifted towards sites with lower humus content but higher aeration. Niche displacement can facilitate the formation of stable contact zones upon secondary contact of polyploids and their lower-ploid ancestors and/or lead to convergence of the cytotypes' niches after they have attained non-overlapping ranges. Niche displacement is essential for understanding ecological consequences of polyploidy. © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Lineage diversification in a widespread species: roles for niche divergence and conservatism in the common kingsnake, Lampropeltis getula.

PubMed

Alexander Pyron, R; Burbrink, Frank T

2009-08-01

Niche conservatism and niche divergence are both important ecological mechanisms associated with promoting allopatric speciation across geographical barriers. However, the potential for variable responses in widely distributed organisms has not been fully investigated. For allopatric sister lineages, three patterns for the interaction of ecological niche preference and geographical barriers are possible: (i) niche conservatism at a physical barrier; (ii) niche divergence at a physical barrier; and (iii) niche divergence in the absence of a physical barrier. We test for the presence of these patterns in a transcontinentally distributed snake species, the common kingsnake (Lampropeltis getula), to determine the relative frequency of niche conservatism or divergence in a single species complex inhabiting multiple distinct ecoregions. We infer the phylogeographic structure of the kingsnake using a range-wide data set sampled for the mitochondrial gene cytochrome b. We use coalescent simulation methods to test for the presence of structured lineage formation vs. fragmentation of a widespread ancestor. Finally, we use statistical techniques for creating and evaluating ecological niche models to test for conservatism of ecological niche preferences. Significant geographical structure is present in the kingsnake, for which coalescent tests indicate structured population division. Surprisingly, we find evidence for all three patterns of conservatism and divergence. This suggests that ecological niche preferences may be labile on recent phylogenetic timescales, and that lineage formation in widespread species can result from an interaction between inertial tendencies of niche conservatism and natural selection on populations in ecologically divergent habitats.

Geographic distributions and ecology of ornamental Curcuma (Zingiberaceae) in Northeastern Thailand.

PubMed

Khumkratok, Sutthira; Boongtiang, Kriangsuk; Chutichudet, Prasit; Pramaul, Pairot

2012-10-01

The genus Curcuma is a very important economic plant. Members of this genus were used as food, medicine and ornament plants. The objectives of this study were to examine the geographic distributions and ecological conditions in the natural habitats of Curcuma in Northeastern Thailand. Species diversity was examined using the line transect method. Ecological conditions of the species were examined using a sampling plot of 20 x 20 m. A total of five species were found including Curcuma angustifolia Roxb., C. alismatifolia Gagnep., C. gracillima Gagnep., C. parviflora Wall. and C. rhabdota. These species were in an altitudinal range between 290 m and 831 m above sea level. Four species (C. angustifolia, C. alismatifolia, C. gracillima and C. rhabdota) were distributed in open gaps in dry dipterocarp forest. One species, C. parviflora was found in the contact zone between dry dipterocarp and bamboo (Gigantochloa sp.) forest. C. rhabdota was found only in a habitat with high humidity and shading along the Thailand-Lao PDR border. Significant ecological conditions of the natural habitats of these Curcuma species were identified. Altitude is the most important factor when determining the geographic distributions of these Curcuma species in Northeastern Thailand.

Characterization of the ecological interactions of Roundup Ready 2 Yield® soybean, MON 89788, for use in ecological risk assessment

PubMed Central

Horak, Michael J; Rosenbaum, Eric W; Phillips, Samuel L; Kendrick, Daniel L; Carson, David; Clark, Pete L; Nickson, Thomas E

2015-01-01

Abstract As part of an ecological risk assessment, Roundup Ready 2 Yield® soybean (MON 89788) was compared to a conventional control soybean variety, A3244, for disease and arthropod damage, plant response to abiotic stress and cold, effects on succeeding plant growth (allelopathic effects), plant response to a bacterial symbiont, and effects on the ability of seed to survive and volunteer in a subsequent growing season. Statistically significant differences between MON 89788 and A3244 were considered in the context of the genetic variation known to occur in soybean and were assessed for their potential impact on plant pest (weed) potential and adverse environmental impact. The results of these studies revealed no effects of the genetic modification that would result in increased pest potential or adverse environmental impact of MON 89788 compared with A3244. This paper illustrates how such characterization studies conducted in a range of environments where the crop is grown are used in an ecological risk assessment of the genetically modified (GM) crop. Furthermore, risk assessors and decision makers use this information when deciding whether to approve a GM crop for cultivation in—or grain import into—their country. PMID:26177011

A global review of freshwater crayfish temperature tolerance, preference, and optimal growth

USGS Publications Warehouse

Westhoff, Jacob T.; Rosenberger, Amanda E.

2016-01-01

Conservation efforts, environmental planning, and management must account for ongoing ecosystem alteration due to a changing climate, introduced species, and shifting land use. This type of management can be facilitated by an understanding of the thermal ecology of aquatic organisms. However, information on thermal ecology for entire taxonomic groups is rarely compiled or summarized, and reviews of the science can facilitate its advancement. Crayfish are one of the most globally threatened taxa, and ongoing declines and extirpation could have serious consequences on aquatic ecosystem function due to their significant biomass and ecosystem roles. Our goal was to review the literature on thermal ecology for freshwater crayfish worldwide, with emphasis on studies that estimated temperature tolerance, temperature preference, or optimal growth. We also explored relationships between temperature metrics and species distributions. We located 56 studies containing information for at least one of those three metrics, which covered approximately 6 % of extant crayfish species worldwide. Information on one or more metrics existed for all 3 genera of Astacidae, 4 of the 12 genera of Cambaridae, and 3 of the 15 genera of Parastacidae. Investigations employed numerous methodological approaches for estimating these parameters, which restricts comparisons among and within species. The only statistically significant relationship we observed between a temperature metric and species range was a negative linear relationship between absolute latitude and optimal growth temperature. We recommend expansion of studies examining the thermal ecology of freshwater crayfish and identify and discuss methodological approaches that can improve standardization and comparability among studies.

Emergent long-range synchronization of oscillating ecological populations without external forcing described by Ising universality

PubMed Central

Noble, Andrew E.; Machta, Jonathan; Hastings, Alan

2015-01-01

Understanding the synchronization of oscillations across space is fundamentally important to many scientific disciplines. In ecology, long-range synchronization of oscillations in spatial populations may elevate extinction risk and signal an impending catastrophe. The prevailing assumption is that synchronization on distances longer than the dispersal scale can only be due to environmental correlation (the Moran effect). In contrast, we show how long-range synchronization can emerge over distances much longer than the length scales of either dispersal or environmental correlation. In particular, we demonstrate that the transition from incoherence to long-range synchronization of two-cycle oscillations in noisy spatial population models is described by the Ising universality class of statistical physics. This result shows, in contrast to all previous work, how the Ising critical transition can emerge directly from the dynamics of ecological populations. PMID:25851364

Organochlorine pesticides across the tributaries of River Ravi, Pakistan: Human health risk assessment through dermal exposure, ecological risks, source fingerprints and spatio-temporal distribution.

PubMed

Baqar, Mujtaba; Sadef, Yumna; Ahmad, Sajid Rashid; Mahmood, Adeel; Li, Jun; Zhang, Gan

2018-03-15

This study monitored the human health risks through dermal exposure, hazardous risks to ecological integrity, contamination levels, spatio-temporal distribution, and congener specific analysis of organochlorine pesticides (OCPs) across River Ravi and its three northern tributaries (Nullah Bein, Nullah Basanter and Nullah Deg). The residual levels of OCPs isomers were screened for water (n=54) and surface sediment (n=54) samples from twenty seven sampling sites in two alternate seasons (pre-monsoon and post-monsoon). The ∑OCPs concentrations ranged from 13.61 to 1992.18ng/g dry weight and 12.89 to 128.16ng/L with predominance of β-endosulfan and p,p'-DDT in sediment and water matrixes, respectively. Distribution pattern revealed significantly higher concentrations in upstream and midstream, suggesting considerable transboundary OCPs pollution. Calculated ratios of α-HCH/γ-HCH, o,p'-DDT/p,p'-DDT, (DDE+DDD)/∑DDTs and cis/trans-chlordane for water and sediments identified the fresh addition of lindane, technical DDTs and chlordane in the study area. Risk quotient (RQ) based ecological risk was found to be >1 at all studied streams during both seasons and elucidates higher risks for endosulfan (α-endosulfan) and endrin. Human health risk assessment indicated absence of hazardous (non-carcinogenic) risk through bathing in studied streams; as the hazard index values ranged from 1.09E-05 to 2.48E-02 (acceptable limit; <1). However, the calculated carcinogenic risk possessed by OCPs through dermal exposure ranged from 1.39E-10 to 1.98E-05 that highlighted the considerable carcinogenic risk associated to aldrin, dieldrin, p,p'-DDT and β-endosulfan at certain studied sites. Therefore, the high levels of ecological risk and carcinogenic human health risk had emphasized an immediate elimination of ongoing OCPs addition in the studied area. Copyright © 2017 Elsevier B.V. All rights reserved.

Climatic niche evolution is faster in sympatric than allopatric lineages of the butterfly genus Pyrgus

PubMed Central

Pitteloud, Camille; Arrigo, Nils; Suchan, Tomasz; Mastretta-Yanes, Alicia; Dincă, Vlad; Hernández-Roldán, Juan; Brockmann, Ernst; Chittaro, Yannick; Kleckova, Irena; Fumagalli, Luca; Buerki, Sven; Pellissier, Loïc

2017-01-01

Understanding how speciation relates to ecological divergence has long fascinated biologists. It is assumed that ecological divergence is essential to sympatric speciation, as a mechanism to avoid competition and eventually lead to reproductive isolation, while divergence in allopatry is not necessarily associated with niche differentiation. The impact of the spatial context of divergence on the evolutionary rates of abiotic dimensions of the ecological niche has rarely been explored for an entire clade. Here, we compare the magnitude of climatic niche shifts between sympatric versus allopatric divergence of lineages in butterflies. By combining next-generation sequencing, parametric biogeography and ecological niche analyses applied to a genus-wide phylogeny of Palaearctic Pyrgus butterflies, we compare evolutionary rates along eight climatic dimensions across sister lineages that diverged in large-scale sympatry versus allopatry. In order to examine the possible effects of the spatial scale at which sympatry is defined, we considered three sets of biogeographic assignments, ranging from narrow to broad definition. Our findings suggest higher rates of niche evolution along all climatic dimensions for sister lineages that diverge in sympatry, when using a narrow delineation of biogeographic areas. This result contrasts with significantly lower rates of climatic niche evolution found in cases of allopatric speciation, despite the biogeographic regions defined here being characterized by significantly different climates. Higher rates in allopatry are retrieved when biogeographic areas are too widely defined—in such a case allopatric events may be recorded as sympatric. Our results reveal the macro-evolutionary significance of abiotic niche differentiation involved in speciation processes within biogeographic regions, and illustrate the importance of the spatial scale chosen to define areas when applying parametric biogeographic analyses. PMID:28404781

The 2002 Hayman Fire - ecological benefit or catastrophe? An understory plant community perspective

Treesearch

Paula Fornwalt

2013-01-01

Fire has long been a keystone ecological process in Western forests. In ponderosa pine (Pinus ponderosa)/Douglas-fir (Pseudotsuga menziesii) forests of the Colorado Front Range, historical fires are believed to have been "mixed severity" in nature. That means that these fires are believed to have typically burned within a range of severities from low severity...

Assessment of Ecological Factors as an Integral Part of Academic and Mental Health Consultation

ERIC Educational Resources Information Center

Ysseldyke, Jim; Lekwa, Adam J.; Klingbeil, David A.; Cormier, Damien C.

2012-01-01

The assessment of ecological factors that affect individual mental health or academic functioning is an important component of educational and psychological consultation. Researchers and practitioners have conceptualized such ecological or environmental factors in a variety of ways and from a broad range of perspectives. In this article we…

Role of Design in the Consumer Culture Development: Ecological Context

ERIC Educational Resources Information Center

Pankina, Marina V.; Khrustalyova, Christina ?.; Egarmin, Anton ?.; Shekhova, Natalia V.

2016-01-01

The relevance of the researched problem stems from ecological issues that are a reflection of the contemporary culture crisis covering the whole range of people's interactions with each other, with society and with nature. In many respects, an ecological crisis is an ideological crisis and global environmental problems are impossible to solve…

Comparative ecology of lynx in North America [Chapter 14

Treesearch

Steven W. Buskirk; Leonard F. Ruggiero; Keith B. Aubry; Dean E. Pearson; John R. Squires; Kevin S. McKelvey

2000-01-01

: Lynx occur across a large geographic area, but have only been studied in a few locations, and this has led to extrapolation of understandings into areas with very divergent ecologies. We discuss ecological differences across the range of lynx, contrasting the patterns of climate, vegetation, disturbance dynamics and succession, and predator/prey...

Development of a protocol for the ecological assessment of a special species

Treesearch

David Burton

2004-01-01

Developing consistent inventory and assessment protocols is important to people working on aspen issues in California and Nevada. Efforts have focused on identifying key indicators of ecological condition within aspen stands. The protocols have incorporated a range of factors that create or affect those indicators. Resulting ecological assessments conducted through the...

Model of continual metabolism species for estimating stability of CELSS and natural ecosystems

NASA Astrophysics Data System (ADS)

Bartsev, S. I.

Estimation of stability range of natural and man-made ecosystems is necessary for effective control of them However traditional ecological models usually underestimate stability of real ecosystems It takes place due to the usage of fixed stoichiometry model of metabolism The objective is in creating theoretical and mathematical models for adequate description of both man-made and natural ecological systems A concept of genetically fixed but metabolically flexible species is considered in the paper According to the concept the total flow of matter through ecological system is supported at almost constant level depending on energy income by flexibility of metabolic organization of genetic species It is shown introducing continual metabolism species extends the range of stability making its estimation more adequate to real ecological systems

Climate change and mosquito-borne disease.

PubMed Central

Reiter, P

2001-01-01

Global atmospheric temperatures are presently in a warming phase that began 250--300 years ago. Speculations on the potential impact of continued warming on human health often focus on mosquito-borne diseases. Elementary models suggest that higher global temperatures will enhance their transmission rates and extend their geographic ranges. However, the histories of three such diseases--malaria, yellow fever, and dengue--reveal that climate has rarely been the principal determinant of their prevalence or range; human activities and their impact on local ecology have generally been much more significant. It is therefore inappropriate to use climate-based models to predict future prevalence. PMID:11250812

Pollution data analysis and characteristics of volatile organic compounds in the environment

NASA Astrophysics Data System (ADS)

Wang, Qi; Wang, Chěn; Hou, Lujian; Lv, Bo; WANG, Chén

2018-06-01

Volatile organic compounds (VOCs) have a wide range of sources and have a significant impact on the ecological environment and human health, which have attracted wide attention of many researchers. In this paper, the pollution characteristics of VOCs, the role of VOCs in atmospheric chemistry including OH reaction reactivity (LOH), Ozone Formation Potential (OFP) and SOA generation potential (SOAP), VOCs source apportionment were discussed and reviewed.

Architecture of an Antagonistic Tree/Fungus Network: The Asymmetric Influence of Past Evolutionary History

PubMed Central

Vacher, Corinne; Piou, Dominique; Desprez-Loustau, Marie-Laure

2008-01-01

Background Compartmentalization and nestedness are common patterns in ecological networks. The aim of this study was to elucidate some of the processes shaping these patterns in a well resolved network of host/pathogen interactions. Methology/Principal Findings Based on a long-term (1972–2005) survey of forest health at the regional scale (all French forests; 15 million ha), we uncovered an almost fully connected network of 51 tree taxa and 157 parasitic fungal species. Our analyses revealed that the compartmentalization of the network maps out the ancient evolutionary history of seed plants, but not the ancient evolutionary history of fungal species. The very early divergence of the major fungal phyla may account for this asymmetric influence of past evolutionary history. Unlike compartmentalization, nestedness did not reflect any consistent phylogenetic signal. Instead, it seemed to reflect the ecological features of the current species, such as the relative abundance of tree species and the life-history strategies of fungal pathogens. We discussed how the evolution of host range in fungal species may account for the observed nested patterns. Conclusion/Significance Overall, our analyses emphasized how the current complexity of ecological networks results from the diversification of the species and their interactions over evolutionary times. They confirmed that the current architecture of ecological networks is not only dependant on recent ecological processes. PMID:18320058

Geographic variation in genetic and demographic performance: new insights from an old biogeographical paradigm.

PubMed

Pironon, Samuel; Papuga, Guillaume; Villellas, Jesús; Angert, Amy L; García, María B; Thompson, John D

2017-11-01

The 'centre-periphery hypothesis' (CPH) is a long-standing postulate in ecology that states that genetic variation and demographic performance of a species decrease from the centre to the edge of its geographic range. This hypothesis is based on an assumed concordance between geographical peripherality and ecological marginality such that environmental conditions become harsher towards the limits of a species range. In this way, the CPH sets the stage for understanding the causes of distribution limits. To date, no study has examined conjointly the consistency of these postulates. In an extensive literature review we discuss the birth and development of the CPH and provide an assessment of the CPH by reviewing 248 empirical studies in the context of three main themes. First, a decrease in species occurrence towards their range limits was observed in 81% of studies, while only 51% demonstrated reduced abundance of individuals. A decline in genetic variation, increased differentiation among populations and higher rates of inbreeding were demonstrated by roughly one in two studies (47, 45 and 48%, respectively). However, demographic rates, size and population performance less often followed CPH expectations (20-30% of studies). We highlight the impact of important methodological, taxonomic, and biogeographical biases on such validation rates. Second, we found that geographic and ecological marginality gradients are not systematically concordant, which casts doubt on the reliability of a main assumption of the CPH. Finally, we attempt to disentangle the relative contribution of geographical, ecological and historical processes on the spatial distribution of genetic and demographic parameters. While ecological marginality gradients explain variation in species' demographic performance better than geographic gradients, contemporary and historical factors may contribute interactively to spatial patterns of genetic variation. We thereby propose a framework that integrates species' ecological niche characteristics together with current and past range structure to investigate spatial patterns of genetic and demographic variation across species ranges. © 2016 Cambridge Philosophical Society.

Pacific sleeper shark Somniosus pacificus trophic ecology in the eastern North Pacific Ocean inferred from nitrogen and carbon stable-isotope ratios and diet.

PubMed

Courtney, D L; Foy, R

2012-04-01

Stable-isotope ratios of nitrogen (δ¹⁵N) and lipid-normalized carbon (δ¹³C') were used to examine geographic and ontogenetic variability in the trophic ecology of a high latitude benthopelagic elasmobranch, the Pacific sleeper shark Somniosus pacificus. Mean muscle tissue δ¹³C' values of S. pacificus differed significantly among geographic regions of the eastern North Pacific Ocean. Linear models identified significant ontogenetic and geographic variability in muscle tissue δ¹⁵N values of S. pacificus. The trophic position of S. pacificus in the eastern North Pacific Ocean estimated here from previously published stomach-content data (4·3) was within the range of S. pacificus trophic position predicted from a linear model of S. pacificus muscle tissue δ¹⁵N (3·3-5·7) for fish of the same mean total length (L(T) ; 201·5 cm), but uncertainty in predicted trophic position was very high (95% prediction intervals ranged from 2·9 to 6·4). The relative trophic position of S. pacificus determined here from a literature review of δ¹⁵N by taxa in the eastern North Pacific Ocean was also lower than would be expected based on stomach-content data alone when compared to fishes, squid and filter feeding whales. Stable-isotope analysis revealed wider variability in the feeding ecology of S. pacificus in the eastern North Pacific Ocean than shown by diet data alone, and expanded previous conclusions drawn from analyses of stomach-content data to regional and temporal scales meaningful for fisheries management. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.

Comparative aerodynamic performance of flapping flight in two bat species using time-resolved wake visualization

PubMed Central

Muijres, Florian T.; Johansson, L. Christoffer; Winter, York; Hedenström, Anders

2011-01-01

Bats are unique among extant actively flying animals in having very flexible wings, controlled by multi-jointed fingers. This gives the potential for fine-tuned active control to optimize aerodynamic performance throughout the wingbeat and thus a more efficient flight. But how bat wing performance scales with size, morphology and ecology is not yet known. Here, we present time-resolved fluid wake data of two species of bats flying freely across a range of flight speeds using stereoscopic digital particle image velocimetry in a wind tunnel. From these data, we construct an average wake for each bat species and speed combination, which is used to estimate the flight forces throughout the wingbeat and resulting flight performance properties such as lift-to-drag ratio (L/D). The results show that the wake dynamics and flight performance of both bat species are similar, as was expected since both species operate at similar Reynolds numbers (Re) and Strouhal numbers (St). However, maximum L/D is achieved at a significant higher flight speed for the larger, highly mobile and migratory bat species than for the smaller non-migratory species. Although the flight performance of these bats may depend on a range of morphological and ecological factors, the differences in optimal flight speeds between the species could at least partly be explained by differences in their movement ecology. PMID:21367776

Feeding ecology of lake whitefish larvae in eastern Lake Ontario

USGS Publications Warehouse

Johnson, James H.; McKenna, James E.; Chalupnicki, Marc A.; Wallbridge, Tim; Chiavelli, Rich

2009-01-01

We examined the feeding ecology of larval lake whitefish (Coregonus clupeaformis) in Chaumont Bay, Lake Ontario, during April and May 2004-2006. Larvae were collected with towed ichthyoplankton nets offshore and with larval seines along the shoreline. Larval feeding periodicity was examined from collections made at 4-h intervals over one 24-h period in 2005. Inter-annual variation in diet composition (% dry weight) was low, as was spatial variation among collection sites within the bay. Copepods (81.4%), primarily cyclopoids (59.1%), were the primary prey of larvae over the 3-year period. Cladocerans (8.1%; mainly daphnids, 6.7%) and chironomids (7.3%) were the other major prey consumed. Larvae did not exhibit a preference for any specific prey taxa. Food consumption of lake whitefish larvae was significantly lower at night (i.e., 2400 and 0400 h). Substantial variation in diet composition occurred over the 24-h diel study. For the 24-h period, copepods were the major prey consumed (50.4%) and their contribution in the diet ranged from 29.3% (0400 h) to 85.9% (1200 h). Chironomids made up 33.4% of the diel diet, ranging from 8.0% (0800 h) to 69.9% (0400 h). Diel variation in the diet composition of lake whitefish larvae may require samples taken at several intervals over a 24-h period to gain adequate representation of their feeding ecology.

[Population ecology of Crocodylus acutus (Reptilia: Crocodylidae) in Palmasola lagoon, Oaxaca, Mexico].

PubMed

García-Grajales, Jesús; Silva, Alejandra Buenrostro

2014-03-01

Population ecology of Crocodylus acutus (Reptilia: Crocodylidae) in Palmasola lagoon, Oaxaca, Mexico. Abundance and population structure are important parameters to evaluate and compare the conservation status of a population over time in a given area. This study describes the population abundance and structure of Crocodylus acutus in Palmasola lagoon, Oaxaca. The field works consisted of night surveys during the new moon phase, between the 21:00 and 24:00h. These were conducted during the dry and wet seasons and counted the number of individuals to obtain population estimates. Recorded encounter rates ranged from 32 to 109.3ind./ km in 40 journeys deployed with an average time of 18 minutes browsing. The estimated population size using the Messel's model ranged from 32.7 to 93 individuals. For both seasons, there was a marked dominance of subadults, followed by juveniles and to a lesser extent adult individuals, as well as undetermined individuals (i.e. unknown body/size/length), in both seasons. There was also a significant association with mangrove areas (26.1%) by juveniles; the subadults's individual use of superficial water (22.7%) and mangrove areas (15.7%); meanwhile the adults were observed on superficial water (9.7%). This information contributes to our understanding of the population ecology of C. acutus in the Palmasola lagoon where the estimated population size seems to show higher values when compared to other reports in the country.

Range contraction in large pelagic predators

PubMed Central

Worm, Boris; Tittensor, Derek P.

2011-01-01

Large reductions in the abundance of exploited land predators have led to significant range contractions for those species. This pattern can be formalized as the range–abundance relationship, a general macroecological pattern that has important implications for the conservation of threatened species. Here we ask whether similar responses may have occurred in highly mobile pelagic predators, specifically 13 species of tuna and billfish. We analyzed two multidecadal global data sets on the spatial distribution of catches and fishing effort targeting these species and compared these with available abundance time series from stock assessments. We calculated the effort needed to reliably detect the presence of a species and then computed observed range sizes in each decade from 1960 to 2000. Results suggest significant range contractions in 9 of the 13 species considered here (between 2% and 46% loss of observed range) and significant range expansions in two species (11–29% increase). Species that have undergone the largest declines in abundance and are of particular conservation concern tended to show the largest range contractions. These include all three species of bluefin tuna and several marlin species. In contrast, skipjack tuna, which may have increased its abundance in the Pacific, has also expanded its range size. These results mirror patterns described for many land predators, despite considerable differences in habitat, mobility, and dispersal, and imply ecological extirpation of heavily exploited species across parts of their range. PMID:21693644

Testing for local adaptation and evolutionary potential along altitudinal gradients in rainforest Drosophila: beyond laboratory estimates.

PubMed

O'Brien, Eleanor K; Higgie, Megan; Reynolds, Alan; Hoffmann, Ary A; Bridle, Jon R

2017-05-01

Predicting how species will respond to the rapid climatic changes predicted this century is an urgent task. Species distribution models (SDMs) use the current relationship between environmental variation and species' abundances to predict the effect of future environmental change on their distributions. However, two common assumptions of SDMs are likely to be violated in many cases: (i) that the relationship of environment with abundance or fitness is constant throughout a species' range and will remain so in future and (ii) that abiotic factors (e.g. temperature, humidity) determine species' distributions. We test these assumptions by relating field abundance of the rainforest fruit fly Drosophila birchii to ecological change across gradients that include its low and high altitudinal limits. We then test how such ecological variation affects the fitness of 35 D. birchii families transplanted in 591 cages to sites along two altitudinal gradients, to determine whether genetic variation in fitness responses could facilitate future adaptation to environmental change. Overall, field abundance was highest at cooler, high-altitude sites, and declined towards warmer, low-altitude sites. By contrast, cage fitness (productivity) increased towards warmer, lower-altitude sites, suggesting that biotic interactions (absent from cages) drive ecological limits at warmer margins. In addition, the relationship between environmental variation and abundance varied significantly among gradients, indicating divergence in ecological niche across the species' range. However, there was no evidence for local adaptation within gradients, despite greater productivity of high-altitude than low-altitude populations when families were reared under laboratory conditions. Families also responded similarly to transplantation along gradients, providing no evidence for fitness trade-offs that would favour local adaptation. These findings highlight the importance of (i) measuring genetic variation in key traits under ecologically relevant conditions, and (ii) considering the effect of biotic interactions when predicting species' responses to environmental change. © 2017 The Authors. Global Change Biology Published by John Wiley & Sons Ltd.

Which Factors Determine Spatial Segregation in the South American Opossums (Didelphis aurita and D. albiventris)? An Ecological Niche Modelling and Geometric Morphometrics Approach

PubMed Central

Cáceres, Nilton Carlos; de Moraes Weber, Marcelo; Melo, Geruza Leal; Meloro, Carlo; Sponchiado, Jonas; Carvalho, Renan dos Santos; Bubadué, Jamile de Moura

2016-01-01

Didelphis albiventris and D. aurita are Neotropical marsupials that share a unique evolutionary history and both are largely distributed throughout South America, being primarily allopatric throughout their ranges. In the Araucaria moist forest of Southern Brazil these species are sympatric and they might potentially compete having similar ecology. For this reason, they are ideal biological models to address questions about ecological character displacement and how closely related species might share their geographic space. Little is known about how two morphologically similar species of marsupials may affect each other through competition, if by competitive exclusion and competitive release. We combined ecological niche modeling and geometric morphometrics to explore the possible effects of competition on their distributional ranges and skull morphology. Ecological niche modeling was used to predict their potential distribution and this method enabled us to identify a case of biotic exclusion where the habit generalist D. albiventris is excluded by the presence of the specialist D. aurita. The morphometric analyses show that a degree of shape discrimination occurs between the species, strengthened by allometric differences, which possibly allowed them to occupy marginally different feeding niches supplemented by behavioral shift in contact areas. Overlap in skull morphology is shown between sympatric and allopatric specimens and a significant, but weak, shift in shape occurs only in D. aurita in sympatric areas. This could be a residual evidence of a higher past competition between both species, when contact zones were possibly larger than today. Therefore, the specialist D. aurita acts a biotic barrier to D. albiventris when niche diversity is not available for coexistence. On the other hand, when there is niche diversification (e.g. habitat mosaic), both species are capable to coexist with a minimal competitive effect on the morphology of D. aurita. PMID:27336371

Strong influence of variable treatment on the performance of numerically defined ecological regions.

PubMed

Snelder, Ton; Lehmann, Anthony; Lamouroux, Nicolas; Leathwick, John; Allenbach, Karin

2009-10-01

Numerical clustering has frequently been used to define hierarchically organized ecological regionalizations, but there has been little robust evaluation of their performance (i.e., the degree to which regions discriminate areas with similar ecological character). In this study we investigated the effect of the weighting and treatment of input variables on the performance of regionalizations defined by agglomerative clustering across a range of hierarchical levels. For this purpose, we developed three ecological regionalizations of Switzerland of increasing complexity using agglomerative clustering. Environmental data for our analysis were drawn from a 400 m grid and consisted of estimates of 11 environmental variables for each grid cell describing climate, topography and lithology. Regionalization 1 was defined from the environmental variables which were given equal weights. We used the same variables in Regionalization 2 but weighted and transformed them on the basis of a dissimilarity model that was fitted to land cover composition data derived for a random sample of cells from interpretation of aerial photographs. Regionalization 3 was a further two-stage development of Regionalization 2 where specific classifications, also weighted and transformed using dissimilarity models, were applied to 25 small scale "sub-domains" defined by Regionalization 2. Performance was assessed in terms of the discrimination of land cover composition for an independent set of sites using classification strength (CS), which measured the similarity of land cover composition within classes and the dissimilarity between classes. Regionalization 2 performed significantly better than Regionalization 1, but the largest gains in performance, compared to Regionalization 1, occurred at coarse hierarchical levels (i.e., CS did not increase significantly beyond the 25-region level). Regionalization 3 performed better than Regionalization 2 beyond the 25-region level and CS values continued to increase to the 95-region level. The results show that the performance of regionalizations defined by agglomerative clustering are sensitive to variable weighting and transformation. We conclude that large gains in performance can be achieved by training classifications using dissimilarity models. However, these gains are restricted to a narrow range of hierarchical levels because agglomerative clustering is unable to represent the variation in importance of variables at different spatial scales. We suggest that further advances in the numerical definition of hierarchically organized ecological regionalizations will be possible with techniques developed in the field of statistical modeling of the distribution of community composition.

Reducing the ecological consequences of night-time light pollution: options and developments

PubMed Central

Gaston, Kevin J; Davies, Thomas W; Bennie, Jonathan; Hopkins, John

2012-01-01

1. Much concern has been expressed about the ecological consequences of night-time light pollution. This concern is most often focused on the encroachment of artificial light into previously unlit areas of the night-time environment, but changes in the spectral composition, duration and spatial pattern of light are also recognized as having ecological effects. 2. Here, we examine the potential consequences for organisms of five management options to reduce night-time light pollution. These are to (i) prevent areas from being artificially lit; (ii) limit the duration of lighting; (iii) reduce the ‘trespass’ of lighting into areas that are not intended to be lit (including the night sky); (iv) change the intensity of lighting; and (v) change the spectral composition of lighting. 3. Maintaining and increasing natural unlit areas is likely to be the most effective option for reducing the ecological effects of lighting. However, this will often conflict with other social and economic objectives. Decreasing the duration of lighting will reduce energy costs and carbon emissions, but is unlikely to alleviate many impacts on nocturnal and crepuscular animals, as peak times of demand for lighting frequently coincide with those in the activities of these species. Reducing the trespass of lighting will maintain heterogeneity even in otherwise well-lit areas, providing dark refuges that mobile animals can exploit. Decreasing the intensity of lighting will reduce energy consumption and limit both skyglow and the area impacted by high-intensity direct light. Shifts towards ‘whiter’ light are likely to increase the potential range of environmental impacts as light is emitted across a broader range of wavelengths. 4. Synthesis and applications. The artificial lightscape will change considerably over coming decades with the drive for more cost-effective low-carbon street lighting solutions and growth in the artificially lit area. Developing lighting strategies that minimize adverse ecological impacts while balancing the often conflicting requirements of light for human utility, comfort and safety, aesthetic concerns, energy consumption and carbon emission reduction constitute significant future challenges. However, as both lighting technology and understanding of its ecological effects develop, there is potential to identify adaptive solutions that resolve these conflicts. PMID:23335816

Ecological risk assessment of coastal ecosystems: The case of mangrove forests in Hormozgan Province, Iran.

PubMed

Ghasemi, Saber; Moghaddam, Sina Siavash; Rahimi, Amir; Damalas, Christos A; Naji, Abolfazl

2018-01-01

Sediment quality of mangrove forests in Hormozgan Province of Iran with a focus on two distinct habitats - the Hara Protected Area and the area of the Azini Bay - was studied. The accumulation of heavy metals in the sediments of the Hara Protected Area in terms of concentration was in the order of Pb > Zn > Cu > Cd and in those of the Azini Bay in the order of Zn > Cu > Pb > Cd. Based on Pearson's correlation coefficient, no significant correlations were found between concentrations of heavy metals in the sediments of the Hara Protected Area, while Zn and Pb concentrations were positively correlated in the sediments of the Azini Bay, implying a common pollution source. Common pollution indices, such as Contamination factor (Cf), degree of contamination (Cd), modified contamination degree (mCd), potential ecological risk index (RI) and metal pollution index (MPI), were used for assessing contamination status. The value of contamination (Cd) index was lower than 7 across all five stations of each studied region, implying a low degree of contamination. The modified contamination degree (mCd) index was lower than 1.5, showing that the sediment pollution was low in both regions. The potential ecological risk assessment index was 223.89 and 543.97 for the Hara Protected Area and the Azini Bay, respectively. Based on categorization of Hakanson's ecological risk, the Hara Protected Area region was in the range of 150 ≤ RI ≤ 300 (moderate ecological risk) and the Azini Bay region in the range of 300 ≤ RI ≤ 600 (acceptable ecological risk). Findings raise awareness of the contamination status of mangrove forests in Hormozgan Province, provide a valuable benchmark for future comparisons in the area, and are important for the design of appropriate policies and long-term management of those ecosystems by local managers and the national authorities. Copyright © 2017 Elsevier Ltd. All rights reserved.

Reducing the ecological consequences of night-time light pollution: options and developments.

PubMed

Gaston, Kevin J; Davies, Thomas W; Bennie, Jonathan; Hopkins, John

2012-12-01

1. Much concern has been expressed about the ecological consequences of night-time light pollution. This concern is most often focused on the encroachment of artificial light into previously unlit areas of the night-time environment, but changes in the spectral composition, duration and spatial pattern of light are also recognized as having ecological effects.2. Here, we examine the potential consequences for organisms of five management options to reduce night-time light pollution. These are to (i) prevent areas from being artificially lit; (ii) limit the duration of lighting; (iii) reduce the 'trespass' of lighting into areas that are not intended to be lit (including the night sky); (iv) change the intensity of lighting; and (v) change the spectral composition of lighting.3. Maintaining and increasing natural unlit areas is likely to be the most effective option for reducing the ecological effects of lighting. However, this will often conflict with other social and economic objectives. Decreasing the duration of lighting will reduce energy costs and carbon emissions, but is unlikely to alleviate many impacts on nocturnal and crepuscular animals, as peak times of demand for lighting frequently coincide with those in the activities of these species. Reducing the trespass of lighting will maintain heterogeneity even in otherwise well-lit areas, providing dark refuges that mobile animals can exploit. Decreasing the intensity of lighting will reduce energy consumption and limit both skyglow and the area impacted by high-intensity direct light. Shifts towards 'whiter' light are likely to increase the potential range of environmental impacts as light is emitted across a broader range of wavelengths.4.Synthesis and applications. The artificial lightscape will change considerably over coming decades with the drive for more cost-effective low-carbon street lighting solutions and growth in the artificially lit area. Developing lighting strategies that minimize adverse ecological impacts while balancing the often conflicting requirements of light for human utility, comfort and safety, aesthetic concerns, energy consumption and carbon emission reduction constitute significant future challenges. However, as both lighting technology and understanding of its ecological effects develop, there is potential to identify adaptive solutions that resolve these conflicts.

Monitoring the condition of natural resources in US national parks.

PubMed

Fancy, S G; Gross, J E; Carter, S L

2009-04-01

The National Park Service has developed a long-term ecological monitoring program for 32 ecoregional networks containing more than 270 parks with significant natural resources. The monitoring program assists park managers in developing a broad-based understanding of the status and trends of park resources as a basis for making decisions and working with other agencies and the public for the long-term protection of park ecosystems. We found that the basic steps involved in planning and designing a long-term ecological monitoring program were the same for a range of ecological systems including coral reefs, deserts, arctic tundra, prairie grasslands, caves, and tropical rainforests. These steps involve (1) clearly defining goals and objectives, (2) compiling and summarizing existing information, (3) developing conceptual models, (4) prioritizing and selecting indicators, (5) developing an overall sampling design, (6) developing monitoring protocols, and (7) establishing data management, analysis, and reporting procedures. The broad-based, scientifically sound information obtained through this systems-based monitoring program will have multiple applications for management decision-making, research, education, and promoting public understanding of park resources. When combined with an effective education program, monitoring results can contribute not only to park issues, but also to larger quality-of-life issues that affect surrounding communities and can contribute significantly to the environmental health of the nation.

Using estimates of natural variation to detect ecologically important change in forest spatial patterns: a case study, Cascade Range, eastern Washington.

Treesearch

Paul F. Hessburg; Bradley G. Smith; R. Brion Salter

1999-01-01

Using hierarchical clustering techniques, we grouped subwatersheds on the eastern slope of the Cascade Range in Washington State into ecological subregions by similarity of area in potential vegetation and climate attributes. We then built spatially continuous historical and current vegetation maps for 48 randomly selected subwatersheds from interpretations of 1938-49...

Test Area B-70 Final Range Environmental Assessment, Revision 1

DTIC Science & Technology

2009-06-01

the Sandhills and Open Grassland ecological associations on the Eglin Range, where it excavates a tunnel -like burrow for shelter from climatic extremes...Sciurus niger Gallberry Ilex glabra Least Shrew Cryptotis parva Gopher Apple Licania michauxii Cottontail Rabbit Sylvilagus floridanus Sand Blackberry ...within the Sandhills and Open Grassland ecological associations on Eglin, where it excavates a tunnel - like burrow for shelter from climatic extremes and

Organism and population-level ecological models for ...

EPA Pesticide Factsheets

Ecological risk assessment typically focuses on animal populations as endpoints for regulatory ecotoxicology. Scientists at USEPA are developing models for animal populations exposed to a wide range of chemicals from pesticides to emerging contaminants. Modeled taxa include aquatic and terrestrial invertebrates, fish, amphibians, and birds, and employ a wide range of methods, from matrix-based projection models to mechanistic bioenergetics models and spatially explicit population models. not applicable

Ecology and natural history of the green rat snake at Leslie Canyon National Wildlife Refuge, Cochise County, Arizona

Treesearch

William R. Radke; Jacob W. Malcom

2005-01-01

Green rat snakes (Senticolis triaspis) appear to be rare throughout their range, and little is known about their ecology and life history. Using opportunistically captured S. triaspis coupled with captive observations, natural observations, and radio telemetry, we document several natural history and ecological aspects of the...

Niche Overlap of Congeneric Invaders Supports a Single-Species Hypothesis and Provides Insight into Future Invasion Risk: Implications for Global Management of the Bactrocera dorsalis Complex

PubMed Central

Hill, Matthew P.; Terblanche, John S.

2014-01-01

Background The invasive fruit fly, Bactrocera invadens, has expanded its range rapidly over the past 10 years. Here we aimed to determine if the recent range expansion of Bactrocera invadens into southern Africa can be better understood through niche exploration tools, ecological niche models (ENMs), and through incorporating information about Bactrocera dorsalis s.s., a putative conspecific species from Asia. We test for niche overlap of environmental variables between Bactrocera invadens and Bactrocera dorsalis s.s. as well as two other putative conspecific species, Bactrocera philippinensis and B. papayae. We examine overlap and similarity in the geographical expression of each species’ realised niche through reciprocal distribution models between Africa and Asia. We explore different geographical backgrounds, environmental variables and model complexity with multiple and single Bactrocera species hypotheses in an attempt to predict the recent range expansion of B. invadens into northern parts of South Africa. Principal Findings Bactrocera invadens has a high degree of niche overlap with B. dorsalis s.s. (and B. philippinensis and B. papayae). Ecological niche models built for Bactrocera dorsalis s.s. have high transferability to describe the range of B. invadens, and B. invadens is able to project to the core range of B. dorsalis s.s. The ENMs of both Bactrocera dorsalis and B. dorsalis combined with B. philipenesis and B. papayae have significantly higher predictive ability to capture the distribution points in South Africa than for B. invadens alone. Conclusions/Significance Consistent with other studies proposing these Bactrocera species as conspecific, niche similarity and overlap between these species is high. Considering these other Bactrocera dorsalis complex species simultaneously better describes the range expansion and invasion potential of B. invadens in South Africa. We suggest that these species should be considered the same–at least functionally–and global quarantine and management strategies applied equally to these Bactrocera species. PMID:24587234

Ecological and physiological thermal niches to understand distribution of Chagas disease vectors in Latin America.

PubMed

DE LA Vega, G J; Schilman, P E

2018-03-01

In order to assess how triatomines (Hemiptera, Reduviidae), Chagas disease vectors, are distributed through Latin America, we analysed the relationship between the ecological niche and the limits of the physiological thermal niche in seven species of triatomines. We combined two methodological approaches: species distribution models, and physiological tolerances. First, we modelled the ecological niche and identified the most important abiotic factor for their distribution. Then, thermal tolerance limits were analysed by measuring maximum and minimum critical temperatures, upper lethal temperature, and 'chill-coma recovery time'. Finally, we used phylogenetic independent contrasts to analyse the link between limiting factors and the thermal tolerance range for the assessment of ecological hypotheses that provide a different outlook for the geo-epidemiology of Chagas disease. In triatomines, thermo-tolerance range increases with increasing latitude mainly due to better cold tolerances, suggesting an effect of thermal selection. In turn, physiological analyses show that species reaching southernmost areas have a higher thermo-tolerance than those with tropical distributions, denoting that thermo-tolerance is limiting the southern distribution. Understanding the latitudinal range along its physiological limits of disease vectors may prove useful to test ecological hypotheses and improve strategies and efficiency of vector control at the local and regional levels. © 2017 The Royal Entomological Society.

Derivation of site-specific surface water quality criteria for the protection of aquatic ecosystems near a Korean military training facility.

PubMed

Jeong, Seung-Woo; An, Youn-Joo

2014-01-01

This study suggested the first Korean site-specific ecological surface water quality criteria for the protection of ecosystems near an artillery range at a Korean military training facility. Surface water quality (SWQ) criteria in Korea address human health protection but do not encompass ecological criteria such as limits for metals and explosives. The first objective of this study was to derive site-specific SWQ criteria for the protection of aquatic ecosystems in Hantan River, Korea. The second objective was to establish discharge criteria for the artillery range to protect the aquatic ecosystems of Hantan River. In this study, we first identified aquatic organisms living in the Hantan River, including fishes, reptiles, invertebrates, phytoplankton, zooplankton, and amphibians. Second, we collected ecotoxicity data for these aquatic organisms and constructed an ecotoxicity database for Cd, Cu, Zn, TNT, and RDX. This study determined the ecological maximum permissible concentrations for metals and explosives based on the ecotoxicity database and suggested ecological surface water quality criteria for the Hantan River by considering analytical detection limits. Discharge limit criteria for the shooting range were determined based on the ecological surface water quality criteria suggested for Hantan River with further consideration of the dilution of the contaminants discharged into the river.

Genetic divergence in the common bush-tanager Chlorospingus ophthalmicus (Aves: Emberizidae) throughout Mexican cloud forests: The role of geography, ecology and Pleistocene climatic fluctuations.

PubMed

Maldonado-Sánchez, Denisse; Gutiérrez-Rodríguez, Carla; Ornelas, Juan Francisco

2016-06-01

By integrating mitochondrial DNA (mtDNA), microsatellites and ecological niche modelling (ENM), we investigated the phylogeography of Mexican populations of the common bush-tanager Chlorospingus ophthalmicus to examine the relative role of geographical and ecological features, as well as Pleistocene climatic oscillations in driving the diversification. We sequenced mtDNA of individuals collected throughout the species range in Mexico and genotyped them at seven microsatellite loci. Phylogeographic, population genetics and coalescent methods were used to assess patterns of genetic structure, gene flow and demographic history. ENM was used to infer contractions and expansions at different time periods as well as differences in climatic conditions among lineages. The retrieved mitochondrial and microsatellite groups correspond with the fragmented cloud forest distribution in mountain ranges and morphotectonic provinces. Differing climatic conditions between mountain ranges were detected, and palaeodistribution modelling as well as demographic history analyses, indicated recent population expansions throughout the Sierra Madre Oriental (SMO). The marked genetic structure of C. ophthalmicus was promoted by the presence of ecological and geographical barriers that restricted the movement of individuals among mountain ranges. The SMO was mainly affected by Pleistocene climatic oscillations, with the moist forests model best fitting the displayed genetic patterns of populations in this mountain range. Copyright © 2016 Elsevier Inc. All rights reserved.

Future Scenarios as a Research Tool: Investigating Climate Change Impacts, Adaptation Options and Outcomes for the Great Barrier Reef, Australia.

PubMed

Evans, Louisa S; Hicks, Christina C; Fidelman, Pedro; Tobin, Renae C; Perry, Allison L

2013-01-01

Climate change is a significant future driver of change in coastal social-ecological systems. Our knowledge of impacts, adaptation options, and possible outcomes for marine environments and coastal industries is expanding, but remains limited and uncertain. Alternative scenarios are a way to explore potential futures under a range of conditions. We developed four alternative future scenarios for the Great Barrier Reef and its fishing and tourism industries positing moderate and more extreme (2-3 °C above pre-industrial temperatures) warming for 2050 and contrasting 'limited' and 'ideal' ecological and social adaptation. We presented these scenarios to representatives of key stakeholder groups to assess the perceived viability of different social adaptation options to deliver desirable outcomes under varied contexts.

Diverse and divergent protein post-translational modifications in two growth stages of a natural microbial community

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Zhou; Wang, Yingfeng; Yao, Qiuming

2014-01-01

Detailed characterization of posttranslational modifications (PTMs) of proteins in microbial communities remains a significant challenge. Here we directly identify and quantify a broad range of PTMs (hydroxylation, methylation, citrullination, acetylation, phosphorylation, methylthiolation, S-nitrosylation and nitration) in a natural microbial community from an acid mine drainage site. Approximately 29% of the identified proteins of the dominant Leptospirillum group II bacteria are modified, and 43% of modified proteins carry multiple PTM types. Most PTM events, except S-nitrosylations, have low fractional occupancy. Notably, PTM events are detected on Cas proteins involved in antiviral defense, an aspect of Cas biochemistry not considered previously. Further,more » Cas PTM profiles from Leptospirillum group II differ in early versus mature biofilms. PTM patterns are divergent on orthologues of two closely related, but ecologically differentiated, Leptospirillum group II bacteria. Our results highlight the prevalence and dynamics of PTMs of proteins, with potential significance for ecological adaptation and microbial evolution.« less

Preferred temperature correlates with evaporative water loss in hylid frogs from northern Australia.

PubMed

Tracy, Christopher R; Christian, Keith A

2005-01-01

We measured temperature preferences of 12 species of hylid frogs (Litoria and Cyclorana) from northern Australia in a laboratory thermal gradient. These species represented a range of ecological habitat use (aquatic, terrestrial, arboreal), adult body size (0.5-60 g), and cutaneous resistance to water loss (Rc=0.6-63.1 s cm-1). We found significant differences among species in selected skin temperature and gradient temperature but not in the variances of these measures (an index of precision of temperature selection). The species' differences correlated significantly with cutaneous resistance to water loss, with more-resistant frogs selecting higher skin and substrate temperatures in the thermal gradient, even after phylogenetic relationships are taken into account. Because cutaneous resistance to water loss also correlates with ecological habit (arboreal>terrestrial>aquatic), we suggest that their higher resistance to water loss allows arboreal and terrestrial species better ability to tolerate high temperatures, where growth or locomotory speed may be higher, without the associated risk of desiccation.

Tropical Ecosystems and Ecological Concepts

NASA Astrophysics Data System (ADS)

Osborne, Patrick L.

2000-09-01

Over one third of the earth's terrestrial surface is situated in the tropics, with environments ranging from hot deserts to tropical rain forests. This introductory textbook, aimed at students studying tropical ecology, provides a comprehensive guide to the major tropical biomes and is unique in its balanced coverage of both aquatic and terrestrial systems. The volume considers the human ecological dimension, covering issues such as population growth, urbanization, agriculture and fisheries, natural resource use, and pollution. It is international in scope and addresses global issues such as conservation of biodiversity, climate change, and the concept of ecological sustainability. The text is supported throughout by boxes containing supplementary material on a range of topics and organisms, mathematical concepts and calculations, and is enlivened with clear line diagrams, maps, and photographs. A cross-referenced glossary, extensive bibliography, and comprehensive index are included as further aids to study.

Personalities influence spatial responses to environmental fluctuations in wild fish.

PubMed

Villegas-Ríos, David; Réale, Denis; Freitas, Carla; Moland, Even; Olsen, Esben M

2018-06-11

1.Although growing evidence supports the idea that animal personality can explain plasticity in response to changes in the social environment, it remains to be tested whether it can explain spatial responses of individuals in the face of natural environmental fluctuations. This is a major challenge in ecology and evolution as spatial dynamics link individual- and population-level processes. 2.In this study we investigated the potential of individual personalities to predict differences in fish behaviour in the wild. Specifically, our goal was to answer if individual differences in plasticity of space use to sea surface temperature could be explained by differences in personality along the reactive-proactive axis. 3.To address this question we first conducted repeated standard laboratory assays (i.e. open-field test, novel object test and mirror-stimulation test) to assess the personality type of 76 wild-caught Atlantic cod (Gadus morhua). Next, we released the fish back into the sea and monitored their spatial behaviour over large temporal (16 months) and spatial (a whole fjord) scales, using high-resolution acoustic tracking. 4. We demonstrate that 1) cod personality traits are structured into a proactive-reactive syndrome (proactive fish being more bold, exploratory and aggressive), 2) mean depth use of individuals is mainly driven by sea temperature and 3) personality is a significant predictor of home range changes in the wild, where reactive, but not proactive, individuals reduced their home range as sea temperature increased. 5. These findings expand our understanding of the ecological consequences of animal personality and the mechanisms shaping spatial dynamics of animals in nature. This article is protected by copyright. All rights reserved. © 2018 The Authors Journal of Animal Ecology published by John Wiley & Sons Ltd on behalf of British Ecological Society.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Friesen, H.N.

This summary document presents results in a broad context; it is not limited to findings of the Nevada Applied Ecology Group. This book is organized to present the findings of the Nevada Applied Ecology Group and correlative programs in accordance with the originally stated objectives of the Nevada Applied Ecology Group. This plan, in essence, traces plutonium from its injection into the environment to movement in the ecosystem to development of cleanup techniques. Information on other radionuclides was also obtained and will be presented briefly. Chapter 1 presents a brief description of the ecological setting of the Test Range Complex.more » The results of investigations for plutonium distribution are presented in Chapter 2 for the area surrounding the Test Range Complex and in Chapter 3 for on-site locations. Chapters 4 and 5 present the results of investigations concerned with concentrations and movement, respectively, of plutonium in the ecosystem of the Test Range Complex, and Chapter 6 summarizes the potential hazard from this plutonium. Development of techniques for cleanup and treatment is presented in Chapter 7, and the inventory of radionuclides other than plutonium is presented briefly in Chapter 8.« less

Three explanations for biodiversity hotspots: small range size, geographical overlap and time for species accumulation. An Australian case study.

PubMed

Cook, Lyn G; Hardy, Nate B; Crisp, Michael D

2015-07-01

To understand the generation and maintenance of biodiversity hotspots, we tested three major hypotheses: rates of diversification, ecological limits to diversity, and time for species accumulation. Using dated molecular phylogenies, measures of species' range size and geographical clade overlap, niche modelling, and lineages-through-time plots of Australian Fabaceae, we compared the southwest Australia Floristic Region (SWAFR; a global biodiversity hotspot) with a latitudinally equivalent non-hotspot, southeast Australia (SEA). Ranges of species (real and simulated) were smaller in the SWAFR than in SEA. Geographical overlap of clades was significantly greater for Daviesia in the SWAFR than in SEA, but the inverse for Bossiaea. Lineage diversification rates over the past 10 Myr did not differ between the SWAFR and SEA in either genus. Interaction of multiple factors probably explains the differences in measured diversity between the two regions. Steeper climatic gradients in the SWAFR probably explain the smaller geographical ranges of both genera there. Greater geographical overlap of clades in the SWAFR, combined with a longer time in the region, can explain why Daviesia is far more species-rich there than in SEA. Our results indicate that the time for speciation and ecological limits hypotheses, in concert, can explain the differences in biodiversity. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

Intraspecific ecological niche divergence and reproductive shifts foster cytotype displacement and provide ecological opportunity to polyploids.

PubMed

Karunarathne, Piyal; Schedler, Mara; Martínez, Eric J; Honfi, Ana I; Novichkova, Anastasiia; Hojsgaard, Diego

2018-05-11

Niche divergence between polyploids and their lower ploidy progenitors is one of the primary mechanisms fostering polyploid establishment and adaptive divergence. However, within-species chromosomal and reproductive variability have usually been neglected in community ecology and biodiversity analyses even though they have been recognized to play a role in the adaptive diversification of lineages. We used Paspalum intermedium, a grass species with diverging genetic systems (diploidy vs. autopolyploidy, allogamy vs. autogamy and sexuality vs. apomixis), to recognize the causality of biogeographic patterns, adaptation and ecological flexibility of cytotypes. Chromosome counts and flow cytometry were used to characterize within-species genetic systems diversity. Environmental niche modelling was used to evaluate intraspecific ecological attributes associated with environmental and climatic factors and to assess correlations among ploidy, reproductive modes and ecological conditions ruling species' population dynamics, range expansion, adaptation and evolutionary history. Two dominant cytotypes non-randomly distributed along local and regional geographical scales displayed niche differentiation, a directional shift in niche optima and signs of disruptive selection on ploidy-related ecological aptitudes for the exploitation of environmental resources. Ecologically specialized allogamous sexual diploids were found in northern areas associated with higher temperature, humidity and productivity, while generalist autogamous apomictic tetraploids occurred in southern areas, occupying colder and less productive environments. Four localities with a documented shift in ploidy and four mixed populations in a zone of ecological transition revealed an uneven replacement between cytotypes. Polyploidy and contrasting reproductive traits between cytotypes have promoted shifts in niche optima, and increased ecological tolerance and niche divergence. Ecologically specialized diploids maintain cytotype stability in core areas by displacing tetraploids, while broader ecological preferences and a shift from sexuality to apomixis favoured polyploid colonization in peripheral areas where diploids are displaced, and fostered the ecological opportunity for autotetraploids supporting range expansion to open southern habitats.

Culturally induced range infilling of eastern redcedar: a problem in ecology, an ecological problem, or both?

USGS Publications Warehouse

Streit Krug, Aubrey; Uden, Daniel R.; Allen, Craig R.; Twidwell, Dirac

2017-01-01

The philosopher John Passmore distinguished between (1) “problems in ecology,” or what we might call problems in scientific understanding of ecological change, and (2) “ecological problems,” or what we might call problems faced by societies due to ecological change. The spread of eastern redcedar (Juniperus virginiana) and conversion of the central and southern Great Plains of North America to juniper woodland might be categorized as a problem in ecology, an ecological problem, or both. Here, we integrate and apply two interdisciplinary approaches to problem-solving—social-ecological systems thinking and ecocriticism—to understand the role of human culture in recognizing, driving, and responding to cedar’s changing geographic distribution. We interpret the spread of cedar as a process of culturally induced range infilling due to the ongoing social-ecological impacts of colonization, analyze poetic literary texts to clarify the concepts that have so far informed different cultural values related to cedar, and explore the usefulness of diverse interdisciplinary collaborations and knowledge for addressing social-ecological challenges like cedar spread in the midst of rapidly unfolding global change. Our examination suggests that it is not only possible, but preferable, to address cedar spread as both a scientific and a social problem. Great Plains landscapes are teetering between grassland and woodland, and contemporary human societies both influence and choose how to cope with transitions between these ecological states. We echo previous studies in suggesting that human cultural values about stability and disturbance, especially cultural concepts of fire, will be primary driving factors in determining future trajectories of change on the Great Plains. Although invasion-based descriptors of cedar spread may be useful in ecological research and management, language based on the value of restraint could provide a common vocabulary for effective cross-disciplinary and interdisciplinary communication about the relationship between culture and cedar, as well as an ethical framework for cross-cultural communication, decision-making, and management.

Aquatic predicted no-effect concentrations of 16 polycyclic aromatic hydrocarbons and their ecological risks in surface seawater of Liaodong Bay, China.

PubMed

Wang, Ying; Wang, Juying; Mu, Jingli; Wang, Zhen; Cong, Yi; Yao, Ziwei; Lin, Zhongsheng

2016-06-01

Polycyclic aromatic hydrocarbons (PAHs), a class of ubiquitous pollutants in marine environments, exhibit moderate to high adverse effects on aquatic organisms and humans. However, the lack of PAH toxicity data for aquatic organism has limited evaluation of their ecological risks. In the present study, aquatic predicted no-effect concentrations (PNECs) of 16 priority PAHs were derived based on species sensitivity distribution models, and their probabilistic ecological risks in seawater of Liaodong Bay, Bohai Sea, China, were assessed. A quantitative structure-activity relationship method was adopted to achieve the predicted chronic toxicity data for the PNEC derivation. Good agreement for aquatic PNECs of 8 PAHs based on predicted and experimental chronic toxicity data was observed (R(2)  = 0.746), and the calculated PNECs ranged from 0.011 µg/L to 205.3 µg/L. A significant log-linear relationship also existed between the octanol-water partition coefficient and PNECs derived from experimental toxicity data (R(2)  = 0.757). A similar order of ecological risks for the 16 PAH species in seawater of Liaodong Bay was found by probabilistic risk quotient and joint probability curve methods. The individual high ecological risk of benzo[a]pyrene, benzo[b]fluoranthene, and benz[a]anthracene needs to be determined. The combined ecological risk of PAHs in seawater of Liaodong Bay calculated by the joint probability curve method was 13.9%, indicating a high risk as a result of co-exposure to PAHs. Environ Toxicol Chem 2016;35:1587-1593. © 2015 SETAC. © 2015 SETAC.

Space life sciences: closed ecological systems: earth and space applications.

PubMed

2005-01-01

This issue contains peer-reviewed papers from a workshop on Closed Ecological Systems: Earth and Space Applications at the 35th COSPAR General Assembly in Paris, France, convened in July 2004. The contributions reflected the wide range of international work in the field, especially Europe, Russia, Japan, and the United States. The papers are arranged according to four main themes: 1) Methods of evaluation and theory of closed ecological systems; 2) Reports from recent experiments in closed ecological system facilities; 3) Bioregenerative technologies to advance degree of closure and cycling; and 4) Laboratory studies of small closed ecological systems.

Strategies to determine diversity, growth, and activity of ammonia-oxidizing archaea in soil.

PubMed

Nicol, Graeme W; Prosser, James I

2011-01-01

Ecological studies of soil microorganisms require reliable techniques for assessment of microbial community composition, abundance, growth, and activity. Soil structure and physicochemical properties seriously limit the applicability and value of methods involving direct observation, and ecological studies have focused on communities and populations, rather than single cells or microcolonies. Although ammonia-oxidizing archaea were discovered 5 years ago, there are still no cultured representatives from soil and there remains a lack of knowledge regarding their genomic composition, physiology, or functional diversity. Despite these limitations, however, significant insights into their distribution, growth characteristics, and metabolism have been made through the use of a range of molecular methodologies. As well as the analysis of taxonomic markers such as 16S rRNA genes, the development of PCR primers based on a limited number of (mostly marine) sequences has enabled the analysis of homologues encoding proteins involved in energy and carbon metabolism. This chapter will highlight the range of molecular methodologies available for examining the diversity, growth, and activity of ammonia-oxidizing archaea in the soil environment. Copyright © 2011 Elsevier Inc. All rights reserved.

Ecotypic differentiation matters for latitudinal variation in energy metabolism and flight performance in a butterfly under climate change.

PubMed

Van Dyck, Hans; Holveck, Marie-Jeanne

2016-11-15

Life histories of organisms may vary with latitude as they experience different thermal constraints and challenges. This geographic, intraspecific variation could be of significance for range dynamics under climate change beyond edge-core comparisons. In this study, we did a reciprocal transplant experiment between the temperature-regimes of two latitudes with an ectotherm insect, examining the effects on energy metabolism and flight performance. Pararge aegeria expanded its ecological niche from cool woodland (ancestral) to warmer habitat in agricultural landscape (novel ecotype). Northern males had higher standard metabolic rates than southern males, but in females these rates depended on their ecotype. Southern males flew for longer than northern ones. In females, body mass-corrected flight performance depended on latitude and thermal treatment during larval development and in case of the southern females, their interaction. Our experimental study provides evidence for the role of ecological differentiation at the core of the range to modulate ecophysiology and flight performance at different latitudes, which in turn may affect the climatic responsiveness of the species.

Ecotypic differentiation matters for latitudinal variation in energy metabolism and flight performance in a butterfly under climate change

PubMed Central

Van Dyck, Hans; Holveck, Marie-Jeanne

2016-01-01

Life histories of organisms may vary with latitude as they experience different thermal constraints and challenges. This geographic, intraspecific variation could be of significance for range dynamics under climate change beyond edge-core comparisons. In this study, we did a reciprocal transplant experiment between the temperature-regimes of two latitudes with an ectotherm insect, examining the effects on energy metabolism and flight performance. Pararge aegeria expanded its ecological niche from cool woodland (ancestral) to warmer habitat in agricultural landscape (novel ecotype). Northern males had higher standard metabolic rates than southern males, but in females these rates depended on their ecotype. Southern males flew for longer than northern ones. In females, body mass-corrected flight performance depended on latitude and thermal treatment during larval development and in case of the southern females, their interaction. Our experimental study provides evidence for the role of ecological differentiation at the core of the range to modulate ecophysiology and flight performance at different latitudes, which in turn may affect the climatic responsiveness of the species. PMID:27845372

Phylogenetic ecology at world scale, a new fusion between ecology and evolution.

PubMed

Westoby, Mark

2006-07-01

One fusion between ecology and evolution is well established, under the title of population biology. The years 2006-2020 will see a new fusion, likely to prove equally creative. Inputs from ecology to this second fusion will be worldwide data sets for ecological traits across many species. Inputs from evolution will be phylogenetic trees with well-resolved topology and with increasingly tight geological dates for each branch point. There will be unification of two aims: first to explain the spread of different ways of making a living, across the range of present-day species; and second, to narrate the evolutionary history that has led up to present-day ecology.

Ecological and Genetic Divergences with Gene Flow of Two Sister Species (Leucomeris decora and Nouelia insignis) Driving by Climatic Transition in Southwest China.

PubMed

Zhao, Yujuan; Yin, Genshen; Pan, Yuezhi; Gong, Xun

2018-01-01

Understanding of the processes of divergence and speciation is a major task for biodiversity researches and may offer clearer insight into mechanisms generating biological diversity. Here, we employ an integrative approach to explore genetic and ecological differentiation of Leucomeris decora and Nouelia insignis distributed allopatrically along the two sides of the biogeographic boundary 'Tanaka Line' in Southwest China. We addressed these questions using ten low-copy nuclear genes and nine plastid DNA regions sequenced among individuals sampled from 28 populations across their geographic ranges in China. Phylogenetic, coalescent-based population genetic analyses, approximate Bayesian computation (ABC) framework and ecological niche models (ENMs) were conducted. We identified a closer phylogenetic relationship in maternal lineage of L. decora with N. insignis than that between L . decora and congeneric Leucomeris spectabilis . A deep divergence between the two species was observed and occurred at the boundary between later Pliocene and early Pleistocene. However, the evidence of significant chloroplast DNA gene flow was also detected between the marginal populations of L. decora and N. insignis . Niche models and statistical analyses showed significant ecological differentiation, and two nuclear loci among the ten nuclear genes may be under divergent selection. These integrative results imply that the role of climatic shift from Pliocene to Pleistocene may be the prominent factor for the divergence of L . decora and N . insignis , and population expansion after divergence may have given rise to chloroplast DNA introgression. The divergence was maintained by differential selection despite in the face of gene flow.

Low Susceptibility of Invasive Red Lionfish (Pterois volitans) to a Generalist Ectoparasite in Both Its Introduced and Native Ranges

PubMed Central

Sikkel, Paul C.; Tuttle, Lillian J.; Cure, Katherine; Coile, Ann Marie; Hixon, Mark A.

2014-01-01

Escape from parasites in their native range is one of many mechanisms that can contribute to the success of an invasive species. Gnathiid isopods are blood-feeding ectoparasites that infest a wide range of fish hosts, mostly in coral reef habitats. They are ecologically similar to terrestrial ticks, with the ability to transmit blood-borne parasites and cause damage or even death to heavily infected hosts. Therefore, being highly resistant or highly susceptible to gnathiids can have significant fitness consequences for reef-associated fishes. Indo-Pacific red lionfish (Pterois volitans) have invaded coastal habitats of the western tropical and subtropical Atlantic and Caribbean regions. We assessed the susceptibility of red lionfish to parasitic gnathiid isopods in both their native Pacific and introduced Atlantic ranges via experimental field studies during which lionfish and other, ecologically-similar reef fishes were caged and exposed to gnathiid infestation on shallow coral reefs. Lionfish in both ranges had very few gnathiids when compared with other species, suggesting that lionfish are not highly susceptible to infestation by generalist ectoparasitic gnathiids. While this pattern implies that release from gnathiid infestation is unlikely to contribute to the success of lionfish as invaders, it does suggest that in environments with high gnathiid densities, lionfish may have an advantage over species that are more susceptible to gnathiids. Also, because lionfish are not completely resistant to gnathiids, our results suggest that lionfish could possibly have transported blood parasites between their native Pacific and invaded Atlantic ranges. PMID:24796701

Low susceptibility of invasive red lionfish (Pterois volitans) to a generalist ectoparasite in both its introduced and native ranges.

PubMed

Sikkel, Paul C; Tuttle, Lillian J; Cure, Katherine; Coile, Ann Marie; Hixon, Mark A

2014-01-01

Escape from parasites in their native range is one of many mechanisms that can contribute to the success of an invasive species. Gnathiid isopods are blood-feeding ectoparasites that infest a wide range of fish hosts, mostly in coral reef habitats. They are ecologically similar to terrestrial ticks, with the ability to transmit blood-borne parasites and cause damage or even death to heavily infected hosts. Therefore, being highly resistant or highly susceptible to gnathiids can have significant fitness consequences for reef-associated fishes. Indo-Pacific red lionfish (Pterois volitans) have invaded coastal habitats of the western tropical and subtropical Atlantic and Caribbean regions. We assessed the susceptibility of red lionfish to parasitic gnathiid isopods in both their native Pacific and introduced Atlantic ranges via experimental field studies during which lionfish and other, ecologically-similar reef fishes were caged and exposed to gnathiid infestation on shallow coral reefs. Lionfish in both ranges had very few gnathiids when compared with other species, suggesting that lionfish are not highly susceptible to infestation by generalist ectoparasitic gnathiids. While this pattern implies that release from gnathiid infestation is unlikely to contribute to the success of lionfish as invaders, it does suggest that in environments with high gnathiid densities, lionfish may have an advantage over species that are more susceptible to gnathiids. Also, because lionfish are not completely resistant to gnathiids, our results suggest that lionfish could possibly have transported blood parasites between their native Pacific and invaded Atlantic ranges.

Physiological, ecological, and behavioural correlates of the size of the geographic ranges of sea kraits (Laticauda; Elapidae, Serpentes): A critique

NASA Astrophysics Data System (ADS)

Heatwole, Harold; Lillywhite, Harvey; Grech, Alana

2016-09-01

Recent, more accurate delineation of the distributions of sea kraits and prior dubious use of proxy temperatures and mean values in correlative studies requires re-assessment of the relationships of temperature and salinity as determinants of the size of the geographic ranges of sea kraits. Correcting the sizes of geographic ranges resolved the paradox of lack of correspondence of size of range with degree of terrestrialism, but did not form a definitive test of the theory. Recent ecological, physiological, and behavioural studies provide an example of the kind of approach likely to either validate or refute present theory.

Effects of Local Habitat Variation on the Behavioral Ecology of Two Sympatric Groups of Brown Howler Monkey (Alouatta clamitans).

PubMed

Jung, Linda; Mourthe, Italo; Grelle, Carlos E V; Strier, Karen B; Boubli, Jean P

2015-01-01

Although the brown howler monkey (Alouatta clamitans) is a relatively well-studied Neotropical primate, its behavioral and dietary flexibility at the intra-population level remains poorly documented. This study presents data collected on the behavior and ecology of two closely located groups of brown howlers during the same period at the RPPN Feliciano Miguel Abdala in southeastern Brazil. One group occupied a primary valley habitat, henceforth the Valley Group (VG), and the other group occupied a regenerating hillside habitat, the Hill Group (HG). We hypothesized differences in the behavior and ecological parameters between these sympatric groups due to the predicted harsher conditions on the hillside, compared to the valley. We measured several habitat parameters within the home range of both groups and collected data on the activity budget, diet and day range lengths, from August to November 2005, between dawn and dusk. In total, behavioral data were collected for 26 (318 h) and 28 (308 h) sampling days for VG and HG, respectively. As we predicted, HG spent significantly more time feeding and consumed less fruit and more leaves than VG, consistent with our finding that the hillside habitat was of lower quality. However, HG also spent less time resting and more time travelling than VG, suggesting that the monkeys had to expend more time and energy to obtain high-energy foods, such as fruits and flowers that were more widely spaced in their hill habitat. Our results revealed that different locations in this forest vary in quality and raise the question of how different groups secure their home ranges. Fine-grained comparisons such as this are important to prioritize conservation and management areas within a reserve.

Poverty, Disease, and the Ecology of Complex Systems

PubMed Central

Pluciński, Mateusz M.; Murray, Megan B.; Farmer, Paul E.; Barrett, Christopher B.; Keenan, Donald C.

2014-01-01

Understanding why some human populations remain persistently poor remains a significant challenge for both the social and natural sciences. The extremely poor are generally reliant on their immediate natural resource base for subsistence and suffer high rates of mortality due to parasitic and infectious diseases. Economists have developed a range of models to explain persistent poverty, often characterized as poverty traps, but these rarely account for complex biophysical processes. In this Essay, we argue that by coupling insights from ecology and economics, we can begin to model and understand the complex dynamics that underlie the generation and maintenance of poverty traps, which can then be used to inform analyses and possible intervention policies. To illustrate the utility of this approach, we present a simple coupled model of infectious diseases and economic growth, where poverty traps emerge from nonlinear relationships determined by the number of pathogens in the system. These nonlinearities are comparable to those often incorporated into poverty trap models in the economics literature, but, importantly, here the mechanism is anchored in core ecological principles. Coupled models of this sort could be usefully developed in many economically important biophysical systems—such as agriculture, fisheries, nutrition, and land use change—to serve as foundations for deeper explorations of how fundamental ecological processes influence structural poverty and economic development. PMID:24690902

Studying sea otter foraging ecology: A review of some methodological approaches

USGS Publications Warehouse

Tinker, M.T.; Estes, J.A.; Bodkin, James L.; Staedler, M.M.; Monson, Daniel H.; Maldini, Daniela; Calkins, Donald; Atkinson, Shannon; Meehan, Rosa

2004-01-01

The study of foraging ecology plays a central role in our understanding of animal populations and natural communities, and can also provide information necessary for the effective conservation of rare or endangered species. Sea otter researchers are interested in foraging ecology for many different reasons, but for heuristic purposes we identify three general types of research questions: (1) questions about the implications of foraging decisions to individual fitness, the evolutionary significance of feeding strategies, and the selective forces and constraints that shape an individual’s diet and feeding behavior; (2) questions about the population- level implications of foraging ecology; for example, how is the status of a population (with respect to carrying capacity) reflected by the foraging success or diet composition of individuals within the population (Fig. 1); and (3) questions about the community-level consequences of sea otter foraging. Sea otters provide an excellent study system for all three types of questions because they are a tractable species to study (generally feeding near shore and bringing all prey to the surface to consume), they exhibit a wide range of diets and foraging strategies in different habitats and at different population densities, they tend to have strong trophic interactions with their prey species, and their foraging behavior can have profound effects on community structure in the nearshore marine community.

Distribution, Seasonal Variations and Ecological Risk Assessment of Polycyclic Aromatic Hydrocarbons in Foliar Dust of Nanjing, China.

PubMed

Zha, Yan; Zhang, Yinlong; Ma, Zilong; Tang, Jie; Sun, Kai

2018-04-01

Polycyclic aromatic hydrocarbons (PAHs) are of concern for both ecosystem and human health due to their potential teratogenic, carcinogenic, and mutagenic properties. The concentration of ∑ 16 PAHs in foliar dust ranged from 49.4 to 19,018.1 µg kg -1 , with a mean value of 7074.5 µg kg -1 . There were significant seasonal variations in the concentration of ∑ 16 PAHs, with the concentration in winter being almost twice as high as in summer. Similarly, the differences between PAH profiles in different seasons indicated that they had common sources, which were attributed to the combined effect of regional transport and local emissions. The diagnostic ratios of indicator compounds indicated that PAHs detected in foliar dust originated from a mixture of gasoline vehicle emissions, biomass, and coal combustion in Nanjing. According to the ecological risk classification of ∑ 16 PAHs, the ecological risk caused by PAHs was high since the value of RQ ∑16PAHs(MPCs) was ≥ 1 and RQ ∑16PAHs(NCs) were ≥ 800. The mean values for RQ∑ 16 PAHs (MPCs) and RQ∑ 16 PAHs (NCs) were 14.8 and 2368.9, which indicated a relatively high ecological risks of PAHs in foliar dust in Nanjing.

Functional ecology of aquatic phagotrophic protists - Concepts, limitations, and perspectives.

PubMed

Weisse, Thomas; Anderson, Ruth; Arndt, Hartmut; Calbet, Albert; Hansen, Per Juel; Montagnes, David J S

2016-08-01

Functional ecology is a subdiscipline that aims to enable a mechanistic understanding of patterns and processes from the organismic to the ecosystem level. This paper addresses some main aspects of the process-oriented current knowledge on phagotrophic, i.e. heterotrophic and mixotrophic, protists in aquatic food webs. This is not an exhaustive review; rather, we focus on conceptual issues, in particular on the numerical and functional response of these organisms. We discuss the evolution of concepts and define parameters to evaluate predator-prey dynamics ranging from Lotka-Volterra to the Independent Response Model. Since protists have extremely versatile feeding modes, we explore if there are systematic differences related to their taxonomic affiliation and life strategies. We differentiate between intrinsic factors (nutritional history, acclimatisation) and extrinsic factors (temperature, food, turbulence) affecting feeding, growth, and survival of protist populations. We briefly consider intraspecific variability of some key parameters and constraints inherent in laboratory microcosm experiments. We then upscale the significance of phagotrophic protists in food webs to the ocean level. Finally, we discuss limitations of the mechanistic understanding of protist functional ecology resulting from principal unpredictability of nonlinear dynamics. We conclude by defining open questions and identifying perspectives for future research on functional ecology of aquatic phagotrophic protists. Copyright © 2016 The Authors. Published by Elsevier GmbH.. All rights reserved.

Poverty, disease, and the ecology of complex systems.

PubMed

Ngonghala, Calistus N; Pluciński, Mateusz M; Murray, Megan B; Farmer, Paul E; Barrett, Christopher B; Keenan, Donald C; Bonds, Matthew H

2014-04-01

Understanding why some human populations remain persistently poor remains a significant challenge for both the social and natural sciences. The extremely poor are generally reliant on their immediate natural resource base for subsistence and suffer high rates of mortality due to parasitic and infectious diseases. Economists have developed a range of models to explain persistent poverty, often characterized as poverty traps, but these rarely account for complex biophysical processes. In this Essay, we argue that by coupling insights from ecology and economics, we can begin to model and understand the complex dynamics that underlie the generation and maintenance of poverty traps, which can then be used to inform analyses and possible intervention policies. To illustrate the utility of this approach, we present a simple coupled model of infectious diseases and economic growth, where poverty traps emerge from nonlinear relationships determined by the number of pathogens in the system. These nonlinearities are comparable to those often incorporated into poverty trap models in the economics literature, but, importantly, here the mechanism is anchored in core ecological principles. Coupled models of this sort could be usefully developed in many economically important biophysical systems--such as agriculture, fisheries, nutrition, and land use change--to serve as foundations for deeper explorations of how fundamental ecological processes influence structural poverty and economic development.

Sponge-Associated Microorganisms: Evolution, Ecology, and Biotechnological Potential†

PubMed Central

Taylor, Michael W.; Radax, Regina; Steger, Doris; Wagner, Michael

2007-01-01

Summary: Marine sponges often contain diverse and abundant microbial communities, including bacteria, archaea, microalgae, and fungi. In some cases, these microbial associates comprise as much as 40% of the sponge volume and can contribute significantly to host metabolism (e.g., via photosynthesis or nitrogen fixation). We review in detail the diversity of microbes associated with sponges, including extensive 16S rRNA-based phylogenetic analyses which support the previously suggested existence of a sponge-specific microbiota. These analyses provide a suitable vantage point from which to consider the potential evolutionary and ecological ramifications of these widespread, sponge-specific microorganisms. Subsequently, we examine the ecology of sponge-microbe associations, including the establishment and maintenance of these sometimes intimate partnerships, the varied nature of the interactions (ranging from mutualism to host-pathogen relationships), and the broad-scale patterns of symbiont distribution. The ecological and evolutionary importance of sponge-microbe associations is mirrored by their enormous biotechnological potential: marine sponges are among the animal kingdom's most prolific producers of bioactive metabolites, and in at least some cases, the compounds are of microbial rather than sponge origin. We review the status of this important field, outlining the various approaches (e.g., cultivation, cell separation, and metagenomics) which have been employed to access the chemical wealth of sponge-microbe associations. PMID:17554047

[Scale effect of Li-Xiang Railway construction impact on landscape pattern and its ecological risk].

PubMed

Wang, De-zhi; Qiu, Peng-hua; Fang, Yuan-min

2015-08-01

As a large corridor project, plateau railway has multiple points and passes various sensitive environments along the railway. The determination of the scope of impact on ecological environment from railway construction is often controversial in ecological impact assessment work. Taking the Tangbu-Jiantang section of Li-Xiang Railway as study object, and using present land use map (1:10000) in 2012 and DEM as data sources, corridor cutting degree index ( CCI) and cumulative effect index of corridor (CCEI) were established by topology, buffer zone and landscape metrics methods. Besides, the ecological risk index used for railway construction was improved. By quantitative analysis of characteristics of the spatio-temporal change of landscape pattern and its evolution style at different spatial scales before and after railway construction, the most appropriate evaluation scale of the railway was obtained. Then the characteristics of the spatio-temporal variation of ecological risk within this scale before and after railway construction were analyzed. The results indicated that the cutting model and degree of railway corridor to various landscape types could be effectively reflected by CCI, and the exposure and harm relations between risk sources and risk receptors of railway can be measured by CCEI. After the railway construction, the railway corridor would cause a great deal of middle cutting effect on the landscape along the railroad, which would influence wood land and grassland landscape most greatly, while would cause less effect of edge cutting and internal cutting. Landscape indices within the 600 m buffer zone demonstrated the most obvious scale effect, therefore, the 600 m zone of the railway was set as the most suitable range of ecological impact assessment. Before railway construction, the low ecological risk level covered the biggest part of the 600 m assessment zone. However, after the railway construction, the ecological risk increased significantly, and the most part of the study area was at the moderate ecological risk level. The ecological risk presented ring-shaped and multi-kernel patterns, and was lower in the southern part than in the northern part of the study area.

“The Whole Family Suffered, so the Whole Family Needs to Recover”: Thematic Analysis of Substance-Abusing Mothers’ Family Therapy Sessions

PubMed Central

Brakenhoff, Brittany; Slesnick, Natasha

2014-01-01

Substance abusing mothers and their children are more likely to experience a range of social, behavioral, and psychological difficulties. Despite the significant challenges faced by these families, little is known about their experiences in treatment. The current study analyzed 12 sessions of family therapy using thematic analysis to identify common themes that arose during substance abusing mothers and their children’s discussion during family therapy. Mothers’ ages ranged from 28 to 35 years and the children’s ages ranged from 12 to 14 years. Four therapy sessions from three families were coded for a total of 12 therapy sessions. An ecological framework was used to classify themes, in which themes related to each level of the families’ ecological systems were identified. Thematic analysis of the therapy sessions indicated that mothers and their children primarily discussed topics related to their relational and emotional needs. The findings indicated that substance use disordered mothers and their children have unique treatment needs that should be addressed when the mother seeks treatment. More research is needed to further clarify and confirm the observations in this study. In particular, future research should include a larger sample and quantitative methodology. PMID:25729116

Ecology of coliphages in southern California coastal waters.

PubMed

Reyes, V C; Jiang, S C

2010-08-01

This study aims to investigate the ecology of coliphages, an important microbial pollution indicator. Specifically, our experiments address (i) the ability of environmental Escherichia coli (E. coli) to serve as hosts for coliphage replication, and (ii) the temporal and spatial distribution of coliphages in coastal waters. Water samples from three locations in California's Newport Bay watershed were tested for the presence of coliphages every 2 weeks for an entire year. A total of nine E. coli strains isolated from various sources served as hosts for coliphage detection. Coliphage occurrence was significantly different between freshwater, estuarine and coastal locations and correlated with water temperature, salinity and rainfall in the watershed. The coliphages isolated on the environmental hosts had a broad host-range relative to the coliphages isolated on an E. coli strain from sewage and a US EPA recommended strain for coliphage detection. Coliphage occurrence was related to the temperature, rainfall and salinity within the bay. The adaptation to a broad host-range may enable the proliferation of coliphages in the aquatic environment. Understanding the seasonal variation of phages is useful for establishing a background level of coliphage presence in coastal waters. The broad host-range of coliphages isolated on the environmental E. coli host calls for investigation of coliphage replication in the aquatic environment.

Predicting species richness and distribution ranges of centipedes at the northern edge of Europe

NASA Astrophysics Data System (ADS)

Georgopoulou, Elisavet; Djursvoll, Per; Simaiakis, Stylianos M.

2016-07-01

In recent decades, interest in understanding species distributions and exploring processes that shape species diversity has increased, leading to the development of advanced methods for the exploitation of occurrence data for analytical and ecological purposes. Here, with the use of georeferenced centipede data, we explore the importance and contribution of bioclimatic variables and land cover, and predict distribution ranges and potential hotspots in Norway. We used a maximum entropy analysis (Maxent) to model species' distributions, aiming at exploring centres of distribution, latitudinal spans and northern range boundaries of centipedes in Norway. The performance of all Maxent models was better than random with average test area under the curve (AUC) values above 0.893 and True Skill Statistic (TSS) values above 0.593. Our results showed a highly significant latitudinal gradient of increased species richness in southern grid-cells. Mean temperatures of warmest and coldest quarters explained much of the potential distribution of species. Predictive modelling analyses revealed that south-eastern Norway and the Atlantic coast in the west (inclusive of the major fjord system of Sognefjord), are local biodiversity hotspots with regard to high predictive species co-occurrence. We conclude that our predicted northward shifts of centipedes' distributions in Norway are likely a result of post-glacial recolonization patterns, species' ecological requirements and dispersal abilities.

Yellowheaded spruce sawfly--its ecology and management.

Treesearch

Steven A. Katovich; Deborah G. McCullough; Robert A. Haack

1995-01-01

Presents the biology and ecology of the yellowheaded spruce sawfly, and provides survey techniques and management strategies. In addition, it provides information on identification, classification, host range, and the historical records of outbreaks in the Lake States.

Preserving Flow Variability in Watershed Model Calibrations

EPA Science Inventory

Background/Question/Methods Although watershed modeling flow calibration techniques often emphasize a specific flow mode, ecological conditions that depend on flow-ecology relationships often emphasize a range of flow conditions. We used informal likelihood methods to investig...

Fish movement and habitat use depends on water body size and shape

USGS Publications Warehouse

Woolnough, D.A.; Downing, J.A.; Newton, T.J.

2009-01-01

Home ranges are central to understanding habitat diversity, effects of fragmentation and conservation. The distance that an organism moves yields information on life history, genetics and interactions with other organisms. Present theory suggests that home range is set by body size of individuals. Here, we analyse estimates of home ranges in lakes and rivers to show that body size of fish and water body size and shape influence home range size. Using 71 studies including 66 fish species on five continents, we show that home range estimates increased with increasing water body size across water body shapes. This contrasts with past studies concluding that body size sets home range. We show that water body size was a consistently significant predictor of home range. In conjunction, body size and water body size can provide improved estimates of home range than just body size alone. As habitat patches are decreasing in size worldwide, our findings have implications for ecology, conservation and genetics of populations in fragmented ecosystems. ?? 2008 Blackwell Munksgaard.

Different Ecological Niches for Ticks of Public Health Significance in Canada

PubMed Central

Gabriele-Rivet, Vanessa; Arsenault, Julie; Badcock, Jacqueline; Cheng, Angela; Edsall, Jim; Goltz, Jim; Kennedy, Joe; Lindsay, L. Robbin; Pelcat, Yann; Ogden, Nicholas H.

2015-01-01

Tick-borne diseases are a growing public health concern as their incidence and range have increased in recent decades. Lyme disease is an emerging infectious disease in Canada due to northward expansion of the geographic range of Ixodes scapularis, the principal tick vector for the Lyme disease agent Borrelia burgdorferi, into central and eastern Canada. In this study the geographical distributions of Ixodid ticks, including I. scapularis, and environmental factors associated with their occurrence were investigated in New Brunswick, Canada, where few I. scapularis populations have been found to date. Density of host-seeking ticks was evaluated by drag sampling of woodland habitats in a total of 159 sites. Ixodes scapularis ticks (n = 5) were found on four sites, Ixodes muris (n = 1) on one site and Haemaphysalis leporispalustris (n = 243) on 41 sites. One of four adult I. scapularis ticks collected was PCR-positive for B. burgdorferi. No environmental variables were significantly associated with the presence of I. scapularis although comparisons with surveillance data in neighbouring provinces (Québec and Nova Scotia) suggested that temperature conditions may be too cold for I. scapularis (< 2800 annual degree days above 0°C [DD > 0°C]) across much of New Brunswick. In contrast, the presence of H. leporispalustris, which is a competent vector of tularaemia, was significantly (P < 0.05) associated with specific ranges of mean DD > 0°C, mean annual precipitation, percentage of clay in site soil, elevation and season in a multivariable logistic regression model. With the exception of some localized areas, temperature conditions and deer density may be too low for the establishment of I. scapularis and Lyme disease risk areas in New Brunswick, while environmental conditions were suitable for H. leporispalustris at many sites. These findings indicate differing ecological niches for two tick species of public health significance. PMID:26131550

Different Ecological Niches for Ticks of Public Health Significance in Canada.

PubMed

Gabriele-Rivet, Vanessa; Arsenault, Julie; Badcock, Jacqueline; Cheng, Angela; Edsall, Jim; Goltz, Jim; Kennedy, Joe; Lindsay, L Robbin; Pelcat, Yann; Ogden, Nicholas H

2015-01-01

Tick-borne diseases are a growing public health concern as their incidence and range have increased in recent decades. Lyme disease is an emerging infectious disease in Canada due to northward expansion of the geographic range of Ixodes scapularis, the principal tick vector for the Lyme disease agent Borrelia burgdorferi, into central and eastern Canada. In this study the geographical distributions of Ixodid ticks, including I. scapularis, and environmental factors associated with their occurrence were investigated in New Brunswick, Canada, where few I. scapularis populations have been found to date. Density of host-seeking ticks was evaluated by drag sampling of woodland habitats in a total of 159 sites. Ixodes scapularis ticks (n = 5) were found on four sites, Ixodes muris (n = 1) on one site and Haemaphysalis leporispalustris (n = 243) on 41 sites. One of four adult I. scapularis ticks collected was PCR-positive for B. burgdorferi. No environmental variables were significantly associated with the presence of I. scapularis although comparisons with surveillance data in neighbouring provinces (Québec and Nova Scotia) suggested that temperature conditions may be too cold for I. scapularis (< 2800 annual degree days above 0°C [DD > 0°C]) across much of New Brunswick. In contrast, the presence of H. leporispalustris, which is a competent vector of tularaemia, was significantly (P < 0.05) associated with specific ranges of mean DD > 0°C, mean annual precipitation, percentage of clay in site soil, elevation and season in a multivariable logistic regression model. With the exception of some localized areas, temperature conditions and deer density may be too low for the establishment of I. scapularis and Lyme disease risk areas in New Brunswick, while environmental conditions were suitable for H. leporispalustris at many sites. These findings indicate differing ecological niches for two tick species of public health significance.

Urban ecological systems: linking terrestrial ecological, physical, and socioeconomic components of metropolitan areas

Treesearch

S.T.A. Pickett; M.L. Cadenasso; M.J. Grove; C.H. Nilon; R.V. Pouyat; W.C. Zipperer

2001-01-01

Ecological studies of terrestrial urban systems have been approached along several kinds of contrasts: ecology in as opposed to ecology of cities; biogeochemical compared to organismal perspectives, land use planning versus biological, and disciplinary versus interdisciplinary. In order to point out how urban ecological studies are poised for significant integration,...

Effective discharge analysis of ecological processes in streams

USGS Publications Warehouse

Doyle, Martin W.; Stanley, Emily H.; Strayer, David L.; Jacobson, Robert B.; Schmidt, John C.

2005-01-01

Discharge is a master variable that controls many processes in stream ecosystems. However, there is uncertainty of which discharges are most important for driving particular ecological processes and thus how flow regime may influence entire stream ecosystems. Here the analytical method of effective discharge from fluvial geomorphology is used to analyze the interaction between frequency and magnitude of discharge events that drive organic matter transport, algal growth, nutrient retention, macroinvertebrate disturbance, and habitat availability. We quantify the ecological effective discharge using a synthesis of previously published studies and modeling from a range of study sites. An analytical expression is then developed for a particular case of ecological effective discharge and is used to explore how effective discharge varies within variable hydrologic regimes. Our results suggest that a range of discharges is important for different ecological processes in an individual stream. Discharges are not equally important; instead, effective discharge values exist that correspond to near modal flows and moderate floods for the variable sets examined. We suggest four types of ecological response to discharge variability: discharge as a transport mechanism, regulator of habitat, process modulator, and disturbance. Effective discharge analysis will perform well when there is a unique, essentially instantaneous relationship between discharge and an ecological process and poorly when effects of discharge are delayed or confounded by legacy effects. Despite some limitations the conceptual and analytical utility of the effective discharge analysis allows exploring general questions about how hydrologic variability influences various ecological processes in streams.

Biogeographic patterns of bacterial microdiversity in Arctic deep-sea sediments (HAUSGARTEN, Fram Strait)

PubMed Central

Buttigieg, Pier Luigi; Ramette, Alban

2015-01-01

Marine bacteria colonizing deep-sea sediments beneath the Arctic ocean, a rapidly changing ecosystem, have been shown to exhibit significant biogeographic patterns along transects spanning tens of kilometers and across water depths of several thousand meters (Jacob et al., 2013). Jacob et al. (2013) adopted what has become a classical view of microbial diversity – based on operational taxonomic units clustered at the 97% sequence identity level of the 16S rRNA gene – and observed a very large microbial community replacement at the HAUSGARTEN Long Term Ecological Research station (Eastern Fram Strait). Here, we revisited these data using the oligotyping approach and aimed to obtain new insight into ecological and biogeographic patterns associated with bacterial microdiversity in marine sediments. We also assessed the level of concordance of these insights with previously obtained results. Variation in oligotype dispersal range, relative abundance, co-occurrence, and taxonomic identity were related to environmental parameters such as water depth, biomass, and sedimentary pigment concentration. This study assesses ecological implications of the new microdiversity-based technique using a well-characterized dataset of high relevance for global change biology. PMID:25601856

Range shift and introgression of the rear and leading populations in two ecologically distinct Rubus species.

PubMed

Mimura, Makiko; Mishima, Misako; Lascoux, Martin; Yahara, Tetsukazu

2014-10-25

The margins of a species' range might be located at the margins of a species' niche, and in such cases, can be highly vulnerable to climate changes. They, however, may also undergo significant evolutionary changes due to drastic population dynamics in response to climate changes, which may increase the chances of isolation and contact among species. Such species interactions induced by climate changes could then regulate or facilitate further responses to climatic changes. We hypothesized that climate changes lead to species contacts and subsequent genetic exchanges due to differences in population dynamics at the species boundaries. We sampled two closely related Rubus species, one temperate (Rubus palmatus) and the other subtropical (R. grayanus) near their joint species boundaries in southern Japan. Coalescent analysis, based on molecular data and ecological niche modelling during the Last Glacial Maximum (LGM), were used to infer past population dynamics. At the contact zones on Yakushima (Yaku Island), where the two species are parapatrically distributed, we tested hybridization along altitudinal gradients. Coalescent analysis suggested that the southernmost populations of R. palmatus predated the LGM (~20,000 ya). Conversely, populations at the current northern limit of R. grayanus diverged relatively recently and likely represent young outposts of a northbound range shift. These population dynamics were partly supported by the ensemble forecasting of six different species distribution models. Both past and ongoing hybridizations were detected near and on Yakushima. Backcrosses and advanced-generation hybrids likely generated the clinal hybrid zones along altitudinal gradients on the island where the two species are currently parapatrically distributed. Climate oscillations during the Quaternary Period and the response of a species in range shifts likely led to repeated contacts with the gene pools of ecologically distinct relatives. Such species interactions, induced by climate changes, may bring new genetic material to the marginal populations where species tend to experience more extreme climatic conditions at the margins of the species distribution.

Ecology, distribution, and predictive occurrence modeling of Palmers chipmunk (Tamias palmeri): a high-elevation small mammal endemic to the Spring Mountains in southern Nevada, USA

USGS Publications Warehouse

Lowrey, Chris E.; Longshore, Kathleen M.; Riddle, Brett R.; Mantooth, Stacy

2016-01-01

Although montane sky islands surrounded by desert scrub and shrub steppe comprise a large part of the biological diversity of the Basin and Range Province of southwestern North America, comprehensive ecological and population demographic studies for high-elevation small mammals within these areas are rare. Here, we examine the ecology and population parameters of the Palmer’s chipmunk (Tamias palmeri) in the Spring Mountains of southern Nevada, and present a predictive GIS-based distribution and probability of occurrence model at both home range and geographic spatial scales. Logistic regression analyses and Akaike Information Criterion model selection found variables of forest type, slope, and distance to water sources as predictive of chipmunk occurrence at the geographic scale. At the home range scale, increasing population density, decreasing overstory canopy cover, and decreasing understory canopy cover contributed to increased survival rates.

Effects of fragmentation on the spatial ecology of the California Kingsnake (Lampropeltis californiae)

USGS Publications Warehouse

Anguiano, Michael P.; Diffendorfer, James E.

2015-01-01

We investigated the spatial ecology of the California Kingsnake (Lampropeltis californiae) in unfragmented and fragmented habitat with varying patch sizes and degrees of exposure to urban edges. We radiotracked 34 Kingsnakes for up to 3 yr across four site types: interior areas of unfragmented ecological reserves, the urbanized edge of these reserves, large habitat fragments, and small habitat fragments. There was no relationship between California Kingsnake movements and the degree of exposure to urban edges and fragmentation. Home range size and movement patterns of Kingsnakes on edges and fragments resembled those in unfragmented sites. Average home-range size on each site type was smaller than the smallest fragment in which snakes were tracked. The persistence of California Kingsnakes in fragmented landscapes may be related directly to their small spatial movement patterns, home-range overlap, and ability to use urban edge habitat.

Climate-driven range shifts of the king penguin in a fragmented ecosystem

NASA Astrophysics Data System (ADS)

Cristofari, Robin; Liu, Xiaoming; Bonadonna, Francesco; Cherel, Yves; Pistorius, Pierre; Le Maho, Yvon; Raybaud, Virginie; Stenseth, Nils Christian; Le Bohec, Céline; Trucchi, Emiliano

2018-03-01

Range shift is the primary short-term species response to rapid climate change, but it is often hampered by natural or anthropogenic habitat fragmentation. Different critical areas of a species' niche may be exposed to heterogeneous environmental changes and modelling species response under such complex spatial and ecological scenarios presents well-known challenges. Here, we use a biophysical ecological niche model validated through population genomics and palaeodemography to reconstruct past range shifts and identify future vulnerable areas and potential refugia of the king penguin in the Southern Ocean. Integrating genomic and demographic data at the whole-species level with specific biophysical constraints, we present a refined framework for predicting the effect of climate change on species relying on spatially and ecologically distinct areas to complete their life cycle (for example, migratory animals, marine pelagic organisms and central-place foragers) and, in general, on species living in fragmented ecosystems.

Developing ecological site and state-and-transition models for grazed riparian pastures at Tejon Ranch, California

Treesearch

Felix P. Ratcliff; James Bartolome; Michele Hammond; Sheri Spiegal; Michael White

2015-01-01

Ecological site descriptions and associated state-and-transition models are useful tools for understanding the variable effects of management and environment on range resources. Models for woody riparian sites have yet to be fully developed. At Tejon Ranch, in the southern San Joaquin Valley of California, we are using ecological site theory to investigate the role of...

Ecological Speciation in Nolina parviflora (Asparagaceae): Lacking Spatial Connectivity along of the Trans-Mexican Volcanic Belt

PubMed Central

Ruiz-Sanchez, Eduardo; Specht, Chelsea D.

2014-01-01

The hypothesis of ecological speciation states that as populations diverge in different niches, reproductive isolation evolves as a by-product of adaptation to these different environments. In this context, we used Nolina parviflora as a model to test if this species evolved via ecological speciation and to explore current and historical gene flow among its populations. Nolina parviflora is a montane species endemic to Mexico with its geographical distribution restricted largely to the Trans-Mexican Volcanic Belt. This mountain range is one of the most complex geological regions in Mexico, having undergone volcanism from the mid-Miocene to the present. Ecologically, the Trans-Mexican Volcanic Belt possesses different types of vegetation, including tropical dry forest; oak, pine, pine-oak, and pine-juniper forests; and xerophytic scrub - all of which maintain populations of N. parviflora. Using species distribution models, climatic analyses, spatial connectivity and morphological comparisons, we found significant differences in climatic and morphological variables between populations of N. parviflora in two distinct Trans-Mexican Volcanic Belt regions (east vs. west). This could mean that the geographically isolated populations diverged from one another via niche divergence, indicating ecological speciation. Spatial connectivity analysis revealed no connectivity between these regions under the present or last glacial maximum climate models, indicating a lack of gene flow between the populations of the two regions. The results imply that these populations may encompass more than a single species. PMID:24905911

Ecological speciation in Nolina parviflora (Asparagaceae): lacking spatial connectivity along of the Trans-Mexican Volcanic Belt.

PubMed

Ruiz-Sanchez, Eduardo; Specht, Chelsea D

2014-01-01

The hypothesis of ecological speciation states that as populations diverge in different niches, reproductive isolation evolves as a by-product of adaptation to these different environments. In this context, we used Nolina parviflora as a model to test if this species evolved via ecological speciation and to explore current and historical gene flow among its populations. Nolina parviflora is a montane species endemic to Mexico with its geographical distribution restricted largely to the Trans-Mexican Volcanic Belt. This mountain range is one of the most complex geological regions in Mexico, having undergone volcanism from the mid-Miocene to the present. Ecologically, the Trans-Mexican Volcanic Belt possesses different types of vegetation, including tropical dry forest; oak, pine, pine-oak, and pine-juniper forests; and xerophytic scrub--all of which maintain populations of N. parviflora. Using species distribution models, climatic analyses, spatial connectivity and morphological comparisons, we found significant differences in climatic and morphological variables between populations of N. parviflora in two distinct Trans-Mexican Volcanic Belt regions (east vs. west). This could mean that the geographically isolated populations diverged from one another via niche divergence, indicating ecological speciation. Spatial connectivity analysis revealed no connectivity between these regions under the present or last glacial maximum climate models, indicating a lack of gene flow between the populations of the two regions. The results imply that these populations may encompass more than a single species.

THE MULTIDISCIPLINARY INFLUENCE OF COMMON SUSTAINABILITY INDICES

EPA Science Inventory

Sustainability is often poorly defined and difficult to measure. We describe several concepts based in ecology, economics, and physics that have contributed to sustainability indices, and discuss their positive and negative aspects. Indices range from mostly ecological (such as e...

Comparative nutrient composition of selected wild edible mushrooms from two agro-ecological zones, Uganda.

PubMed

Nakalembe, Immaculate; Kabasa, John David; Olila, Deogratias

2015-01-01

In Uganda, wild mushrooms are mainly collected during the rainy season and valued as a traditionally nutritious food by the rural poor. However, their nutritional attributes have not been adequately studied and documented. Comparative nutrient composition of five wild edible mushroom species was determined, namely: P. tenucuilus, T. tyleranus, T. clypeatus, V. speciosa and T. microcarpus of sub-humid and humid agro-ecological zones. Standard analytical techniques following the AOAC were used for proximate and mineral contents determinations. Vitamins determination followed the established standard protocols of the laboratories where the analyses were conducted. Combined use of nutrient concentration and scores were used to compare the level of the contents in the mushroom species. Significant differences (p < 0.05) in nutrient values were demonstrated between and among the mushroom species obtained from the two agro-ecological zones. On dry weight basis, all proximate compositions were high in mushroom species obtained from the humid zone with exception of the total carbohydrates and energy values. Irrespective of the source of the mushrooms, significant amounts were demonstrated in protein, dry matter, ash and total carbohydrates ranging between 11.56-27.42%, 82.34-99.76%, 10.79-16.87%, and 37.12-61.05%, respectively. In comparison with recommended dietary daily intakes, the K, P, Se, Mn, Cu and Fe contents were relatively high with low Ca, Mg, Zn and Na. Thiamin, folic acid, vitamin C, and niacin levels were high but below the recommended FAO references. Considering mushrooms from different agro-ecological zones, significant differences (p < 0.05) were observed in all mushroom species in P except in T. clypeatus, T. tyleranus, T. microcarpus and T. clypeatus in potassium, T. clypeatus and T. microcarpus in Mg. Mushrooms from humid agro-ecological zones had relatively high overall mineral and vitamin supply potential. In conclusion, consumption of these mushrooms should be encouraged in supplementation of the staple food of the poor people. Hence, solving malnutrition problems in children, pregnant mothers, and the immune compromised patients such as the HIV/AIDs.

Exploring the universal ecological responses to climate change in a univoltine butterfly.

PubMed

Fenberg, Phillip B; Self, Angela; Stewart, John R; Wilson, Rebecca J; Brooks, Stephen J

2016-05-01

Animals with distinct life stages are often exposed to different temperatures during each stage. Thus, how temperature affects these life stages should be considered for broadly understanding the ecological consequences of climate warming on such species. For example, temperature variation during particular life stages may affect respective change in body size, phenology and geographic range, which have been identified as the "universal" ecological responses to climate change. While each of these responses has been separately documented across a number of species, it is not known whether each response occurs together within a species. The influence of temperature during particular life stages may help explain each of these ecological responses to climate change. Our goal was to determine if monthly temperature variation during particular life stages of a butterfly species can predict respective changes in body size and phenology. We also refer to the literature to assess if temperature variability during the adult stage influences range change over time. Using historical museum collections paired with monthly temperature records, we show that changes in body size and phenology of the univoltine butterfly, Hesperia comma, are partly dependent upon temporal variation in summer temperatures during key stages of their life cycle. June temperatures, which are likely to affect growth rate of the final larval instar, are important for predicting adult body size (for males only; showing a positive relationship with temperature). July temperatures, which are likely to influence the pupal stage, are important for predicting the timing of adult emergence (showing a negative relationship with temperature). Previous studies show that August temperatures, which act on the adult stage, are linked to range change. Our study highlights the importance of considering temperature variation during each life stage over historic time-scales for understanding intraspecific response to climate change. Range edge studies of ectothermic species that have annual life cycles, long time-series occurrence data, and associated temperature records (ideally at monthly resolutions) could be useful model systems for intraspecific tests of the universal ecological responses to climate change and for exploring interactive effects. © 2016 The Authors. Journal of Animal Ecology © 2016 British Ecological Society.

Species-specific ecological niche modelling predicts different range contractions for Lutzomyia intermedia and a related vector of Leishmania braziliensis following climate change in South America.

PubMed

McIntyre, Shannon; Rangel, Elizabeth F; Ready, Paul D; Carvalho, Bruno M

2017-03-24

Before 1996 the phlebotomine sand fly Lutzomyia neivai was usually treated as a synonym of the morphologically similar Lutzomyia intermedia, which has long been considered a vector of Leishmania braziliensis, the causative agent of much cutaneous leishmaniasis in South America. This report investigates the likely range changes of both sand fly species in response to a stabilisation climate change scenario (RCP4.5) and a high greenhouse gas emissions one (RCP8.5). Ecological niche modelling was used to identify areas of South America with climates currently suitable for each species, and then the future distributions of these climates were predicted based on climate change scenarios. Compared with the previous ecological niche model of L. intermedia (sensu lato) produced using the GARP algorithm in 2003, the current investigation modelled the two species separately, making use of verified presence records and additional records after 2001. Also, the new ensemble approach employed ecological niche modelling algorithms (including Maximum Entropy, Random Forests and Support Vector Machines) that have been widely adopted since 2003 and perform better than GARP, as well as using a more recent climate change model (HadGEM2) considered to have better performance at higher resolution than the earlier one (HadCM2). Lutzomyia intermedia was shown to be the more tropical of the two species, with its climatic niche defined by higher annual mean temperatures and lower temperature seasonality, in contrast to the more subtropical L. neivai. These different latitudinal ranges explain the two species' predicted responses to climate change by 2050, with L. intermedia mostly contracting its range (except perhaps in northeast Brazil) and L. neivai mostly shifting its range southwards in Brazil and Argentina. This contradicts the findings of the 2003 report, which predicted more range expansion. The different findings can be explained by the improved data sets and modelling methods. Our findings indicate that climate change will not always lead to range expansion of disease vectors such as sand flies. Ecological niche models should be species specific, carefully selected and combined in an ensemble approach.

Testing the role of interspecific competition in the evolutionary origin of elevational zonation: an example with Buarremon brush-finches (Aves, Emberizidae) in the neotropical mountains.

PubMed

Cadena, Carlos Daniel

2007-05-01

Interspecific competition might drive the evolution of ecological niches and result in pairs of formerly competing species segregating along ecological gradients following a process of character displacement. This mechanism has been proposed to account for replacement of related species along gradients of elevation in many areas of the world, but the fundamental issue of whether competition is responsible for the origin of elevational replacements has not been tested. To test hypotheses about the role of interspecific competition in the origin of complementary elevational ranges, I combined molecular phylogenetics, phylogeography, and population genetic analyses on Buarremon torquatus and B. brunneinucha (Aves, Emberizidae), whose patterns of elevational distribution suggest character displacement or ecological release. The hypothesis that elevational distributions in these species changed in opposite directions as a result of competition is untenable because: (1) a historical expansion of the range of B. brunneinucha into areas occupied by B. torquatus was not accompanied by a shift in the elevational range of the former species; (2) when B. brunneinucha colonized the range of B. torquatus, lineages of the latter distributions had already diverged; and (3) historical trends in effective population size do not suggest populations with elevational ranges abutting those of putative competitors have declined as would be expected if competition caused range contractions. However, owing to uncertainty in coalescent estimates of historical population sizes, the hypothesis that some populations of B. torquatus have declined cannot be confidently rejected, which suggests asymmetric character displacement might have occurred. I suggest that the main role of competition in elevational zonation may be to act as a sorting mechanism that allows the coexistence along mountain slopes only of ecologically similar species that differ in elevational distributions prior to attaining sympatry. The contrasting biogeographic histories of B. brunneinucha and B. torquatus illustrate how present-day ecological interactions can have recent origins, and highlights important challenges for testing the hypothesis of character displacement in the absence of data on population history and robust reconstructions of the evolution of traits and geographic ranges.

Black Ash (Fraxinus nigra Marsh.): Local ecological knowledge of site characteristics and morphology associated with basket-grade specimens in New England (USA)

Treesearch

Allaire K. Diamond; Marla R. Emery

2011-01-01

Fraxinus nigra Marsh. is a small, relatively uncommon tree with large social significance. Known as black ash or brown ash, it rarely exceeds 18 meters (60 feet) in height or 30-50 centimeters (12-20 inches) in diameter. In the U.S. states where the species occurs, its percentage of forest composition ranges from 0.01% in Kentucky to 6.00% in...

Optimal egg size in a suboptimal environment: reproductive ecology of female Sonora mud turtles (Kinosternon sonoriense) in central Arizona, USA

USGS Publications Warehouse

Lovich, Jeffrey E.; Madrak, Sheila V.; Drost, Charles A.; Monatesti, Anthony J.; Casper, Dennis; Znari, Mohammed

2012-01-01

We studied the reproductive ecology of female Sonora mud turtles (Kinosternon sonoriense) at Montezuma Well, a chemically-challenging natural wetland in central Arizona, USA. Females matured between 115.5 and 125 mm carapace length (CL) and 36-54% produced eggs each year. Eggs were detected in X-radiographs from 23 April-28 September (2007-2008) and the highest proportion (56%) of adult females with eggs occurred in June and July. Clutch frequency was rarely more than once per year. Clutch size was weakly correlated with body size, ranged from 1-8 (mean = 4.96) and did not differ significantly between years. X-ray egg width ranged from 17.8-21.7 mm (mean 19.4 mm) and varied more among clutches than within. Mean X-ray egg width of a clutch did not vary significantly with CL of females, although X-ray pelvic aperture width increased with CL. We observed no evidence of a morphological constraint on egg width. In addition, greater variation in clutch size, relative to egg width, suggests that egg size is optimized in this hydrologically stable but chemically-challenging habitat. We suggest that the diversity of architectures exhibited by the turtle pelvis, and their associated lack of correspondence to taxonomic or behavioral groupings, explains some of the variation observed in egg size of turtles.

Gastropod-Borne Helminths: A Look at the Snail-Parasite Interplay.

PubMed

Giannelli, Alessio; Cantacessi, Cinzia; Colella, Vito; Dantas-Torres, Filipe; Otranto, Domenico

2016-03-01

More than 300 million people suffer from a range of diseases caused by gastropod-borne helminths, predominantly flatworms and roundworms, whose life cycles are characterized by a diversified ecology and epidemiology. Despite the plethora of data on these parasites, very little is known of the fundamental biology of their gastropod intermediate hosts, or of the interactions occurring at the snail-helminth interface. In this article, we focus on schistosomes and metastrongylids of human and animal significance, and review current knowledge of snail-parasite interplay. Future efforts aimed at elucidating key elements of the biology and ecology of the snail intermediate hosts, together with an improved understanding of snail-parasite interactions, will aid to identify, plan, and develop new strategies for disease control focused on gastropod intermediate hosts. Copyright © 2015 Elsevier Ltd. All rights reserved.

Bacteriophage Ecology in a Commercial Cucumber Fermentation

PubMed Central

Pérez-Díaz, I. M.; Hayes, J. S.; Breidt, F.

2012-01-01

To reduce high-salt waste from cucumber fermentations, low-salt fermentations are under development. These fermentations may require the use of starter cultures to ensure normal fermentations. Because potential phage infection can cause starter culture failure, it is important to understand phage ecology in the fermentations. This study investigated the phage ecology in a commercial cucumber fermentation. Brine samples taken from a fermentation tank over a 90-day period were plated onto deMan-Rogosa-Sharpe agar plates. A total of 576 lactic acid bacterial isolates were randomly selected to serve as potential hosts for phage isolation. Filtered brine served as a phage source. Fifty-seven independent phage isolates were obtained, indicating that 10% of the bacterial isolates were sensitive to phage attack. Phage hosts include Lactobacillus brevis (67% of all hosts), Lactobacillus plantarum (21%), Weissella paramesenteroides, Weissella cibaria, and Pediococcus ethanolidurans. Nearly 50% of phages were isolated on day 14, and the majority of them attacked L. brevis. Some phages had a broad host range and were capable of infecting multiple hosts in two genera. Other phages were species specific or strain specific. About 30% of phage isolates produced turbid pinpoint plaques or only caused reduced cell growth on the bacterial lawns. Six phages with distinct host ranges were characterized. The data from this study showed that abundant and diverse phages were present in the commercial cucumber fermentation, which could cause significant mortality to the lactic acid bacteria population. Therefore, a phage control strategy may be needed in low-salt cucumber fermentations. PMID:23023756

Elevational patterns of genetic variation in the cosmopolitan moss Bryum argenteum (Bryaceae).

PubMed

Pisa, Sergio; Werner, Olaf; Vanderpoorten, Alain; Magdy, Mahmoud; Ros, Rosa M

2013-10-01

The Baas Becking tenet posits that 'everything is everywhere, but the environment selects' to explain cosmopolitan distributions in highly vagile taxa. Bryophyte species show wider distributions than vascular plants and include examples of truly cosmopolitan ranges, which have been interpreted as a result of high dispersal capacities and ecological plasticity. In the current study, we documented patterns of genetic structure and diversity in the cosmopolitan moss Bryum argenteum along an elevational gradient to determine if genetic diversity and structure is homogenized by intense migrations in the lack of ecological differentiation. • 60 specimens were collected in the Sierra Nevada Mountains (Spain) between 100 and 2870 m and sequenced for ITS and rps4. Comparative analyses, genetic diversity estimators, and Mantel's tests were employed to determine the relationship between genetic variation, elevation, and geographic distance and to look for signs of demographic shifts. • Genetic diversity peaked above 1900 m and no signs of demographic shifts were detected at any elevation. There was a strong phylogenetic component in elevational variation. Genetic variation was significantly correlated with elevation, but not with geographic distance. • The results point to the long-term persistence of Bryum argenteum in a range that was glaciated during the Late Pleistocene. Evidence for an environmentally driven pattern of genetic differentiation suggests adaptive divergence. This supports the Baas Becking tenet and indicates that ecological specialization might play a key role in explaining patterns of genetic structure in cosmopolitan mosses.

Estimation of carbon sequestration in China's forests induced by atmospheric nitrogen deposition: Principles of ecological stoichiometry

NASA Astrophysics Data System (ADS)

Zhu, J.; He, N.; Zhang, J.; Wang, Q.; Zhao, N.; Jia, Y.; Ge, J.; Yu, G.

2017-12-01

The worldwide development of industry and agriculture has generated noticeable increases in atmospheric nitrogen (N) deposition, significantly altering the global N cycle. These changes might affect the global carbon (C) cycle by enhancing forest C sequestration. Here, we measured a series of datasets from eight typical forests along the north-south transect of eastern China (NSTEC). These datasets contained information on community structure, C and N concentrations in the soil and different organs of 877 plant species (leaf, branch, stem, and fine-root), and atmospheric N deposition. Using the biomass weighting method, we scaled up the C:N ratios from the organ level to the ecosystem level, and evaluated the C sequestration rate (CSRN) in response to N deposition and N use efficiency (NUE) in China's forests on the principles of ecological stoichiometry. Our results showed that atmospheric N deposition had a modest impact on forest C storage. Specifically, CSRN was estimated as 231 kg C ha-1 yr-1 (range: 32.7-507.1 kg C ha-1 yr-1), accounting for 2.1% of NPP and 4.6% of NEP at the ecosystem level. The NUE (NUEeco) of atmospheric N deposition ranged from 9.6 to 27.7 kg C kg-1 N, and increased with increasing latitude from subtropical to cold-temperate forests in China (P < 0.05). This study provides a new approach for estimating the effect of atmospheric deposition on forest C sequestration based on the principle of ecological stoichiometry.

Spatial Ecology of the American Crocodile in a Tropical Pacific Island in Central America

PubMed Central

Balaguera-Reina, Sergio A.; Venegas-Anaya, Miryam; Sánchez, Andrés; Arbelaez, Italo; Lessios, Harilaos A.; Densmore, Llewellyn D.

2016-01-01

Conservation of large predators has long been a challenge for biologists due to the limited information we have about their ecology, generally low numbers in the wild, large home ranges and the continuous expansion of human settlements. The American crocodile (Crocodylus acutus) is a typical apex predator, that has suffered from all of these characteristic problems, especially the latter one. Humans have had a major impact on the recovery of this species throughout its range, even though most of the countries it inhabits have banned hunting. The last decade has made it clear that in order to implement sound conservation and management programs, we must increase our understanding of crocodile spatial ecology. However, in only two countries where American crocodiles have telemetry studies even been published. Herein we have characterized the spatial ecology of C. acutus on Coiba Island, Panama, by radio-tracking (VHF transmitters) 24 individuals between 2010 and 2013, to determine movement patterns, home range, and habitat use. We have then compared our findings with those of previous studies to develop the most comprehensive assessment of American crocodile spatial ecology to date. Females showed a higher average movement distance (AMD) than males; similarly, adults showed a higher AMD than sub-adults and juveniles. However, males exhibited larger home ranges than females, and concomitantly sub-adults had larger home ranges than juveniles, hatchlings, and adults. There was an obvious relationship between seasonal precipitation and AMD, with increased AMD in the dry and “low-wet” seasons, and reduced AMD during the “true” wet season. We found disaggregate distributions according to age groups throughout the 9 habitat types in the study area; adults and hatchlings inhabited fewer habitat types than juveniles and sub-adults. These sex- and age-group discrepancies in movement and habitat choice are likely due to the influences of reproductive biology and Coiba’s precipitation cycle. Juveniles also showed distinct movement patterns and home ranges; however, with sexual maturation and development, these behaviors became more characteristic of adults and sub-adults. Ours is one of a very small number of studies that will allow future management and conservation planning to be based on the comprehensive integration of the spatial ecology of a Neotropical crocodylian apex predator. PMID:27280554

Spatial Ecology of the American Crocodile in a Tropical Pacific Island in Central America.

PubMed

Balaguera-Reina, Sergio A; Venegas-Anaya, Miryam; Sánchez, Andrés; Arbelaez, Italo; Lessios, Harilaos A; Densmore, Llewellyn D

2016-01-01

Conservation of large predators has long been a challenge for biologists due to the limited information we have about their ecology, generally low numbers in the wild, large home ranges and the continuous expansion of human settlements. The American crocodile (Crocodylus acutus) is a typical apex predator, that has suffered from all of these characteristic problems, especially the latter one. Humans have had a major impact on the recovery of this species throughout its range, even though most of the countries it inhabits have banned hunting. The last decade has made it clear that in order to implement sound conservation and management programs, we must increase our understanding of crocodile spatial ecology. However, in only two countries where American crocodiles have telemetry studies even been published. Herein we have characterized the spatial ecology of C. acutus on Coiba Island, Panama, by radio-tracking (VHF transmitters) 24 individuals between 2010 and 2013, to determine movement patterns, home range, and habitat use. We have then compared our findings with those of previous studies to develop the most comprehensive assessment of American crocodile spatial ecology to date. Females showed a higher average movement distance (AMD) than males; similarly, adults showed a higher AMD than sub-adults and juveniles. However, males exhibited larger home ranges than females, and concomitantly sub-adults had larger home ranges than juveniles, hatchlings, and adults. There was an obvious relationship between seasonal precipitation and AMD, with increased AMD in the dry and "low-wet" seasons, and reduced AMD during the "true" wet season. We found disaggregate distributions according to age groups throughout the 9 habitat types in the study area; adults and hatchlings inhabited fewer habitat types than juveniles and sub-adults. These sex- and age-group discrepancies in movement and habitat choice are likely due to the influences of reproductive biology and Coiba's precipitation cycle. Juveniles also showed distinct movement patterns and home ranges; however, with sexual maturation and development, these behaviors became more characteristic of adults and sub-adults. Ours is one of a very small number of studies that will allow future management and conservation planning to be based on the comprehensive integration of the spatial ecology of a Neotropical crocodylian apex predator.

Promoting spontaneous adverse drug reaction reporting in hospitals using a hyperlink to the online reporting form: an ecological study in Portugal.

PubMed

Ribeiro-Vaz, Inês; Santos, Cristina; da Costa-Pereira, Altamiro; Cruz-Correia, Ricardo

2012-05-01

Spontaneous adverse drug reaction (ADR) reporting has been described as an efficient method to detect drug safety signals. However, under-reporting is a major issue undermining the effectiveness of spontaneous reports. Among hospitalized patients, ADRs are a particularly serious problem because these patients are often treated with more than one drug, and these drugs are often new and aggressive. To promote spontaneous ADR reporting by healthcare professionals working in hospitals in the northern regions of Portugal, we propose the inclusion of a hyperlink to an online ADR reporting form on hospitals' electronic patient records (EPRs). The main aim of this study was to evaluate the impact of these hyperlinks on the number of spontaneous ADR reports to the Northern Pharmacovigilance Centre (UFN - Unidade de Farmacovigilância do Norte). We also assess the number of daily UFN website visits before and after the inclusion of the hyperlinks. An ecological study was performed in northern Portuguese hospitals from 2006 to 2010. The hyperlinks were included in either EPRs or on computer desktops. The median of spontaneous ADR reports (total and online) per month and the respective ranges were presented before and after the intervention in all hospitals in this study. The comparisons were performed using the Mann-Whitney U-test. Sixteen hospital centres were involved in the study (27 hospitals). Eleven centres (18 hospitals) included the hyperlinks. Considering the hospitals with hyperlink access to the EPRs, the median ADR reports per month significantly increased, from two (range 0-12) to five reports (range 1-17). The median of ADR reports per month using the online form also increased significantly, from one (range 0-5) before the intervention to four (range 1-17) after it. Moreover, serious ADRs increased 3-fold, and non-previously described ADRs increased 4.5-fold. None of these significant increases were observed in the hospitals where the hyperlink was not installed. We also found a significant increase in daily UFN website visits, from ten before the intervention to 27 after it (p < 0.001). The increase in ADR reporting shows that the inclusion of hyperlinks to online ADR reporting forms is an easy and cost-effective way to change health professional behaviours with regard to spontaneous ADR reports.

ECOSYSTEM SERVICES IN THE MID-ATLANTIC UNITED STATES

EPA Science Inventory

Ecological resources have both extrinsic and intrinsic values. These range from the direct economic values

derived from resource harvests, to inherently ecological characteristics that are necessary for ecosystem

functioning, and finally to societal value that human...

Organism and population-level ecological models for chemical risk assessment

EPA Science Inventory

Ecological risk assessment typically focuses on animal populations as endpoints for regulatory ecotoxicology. Scientists at USEPA are developing models for animal populations exposed to a wide range of chemicals from pesticides to emerging contaminants. Modeled taxa include aquat...

Managing the Mississippi River floodplain: Achieving ecological benefits requires more than hydrological connection to the river: Chapter

USGS Publications Warehouse

Schramm, Harold; Richardson, William B.; Knights, Brent C.

2015-01-01

Floodplains are vital to the structure and function of river-floodplain ecosystems. Among the many ecological services provided by floodplains are nutrient cycling and seasonal habitats for fish, including spawning, nursery, foraging and wintering habitats. Connections between the river channel and floodplain habitats are essential to realize these ecological services, but spatial and temporal aspects of the connection and contemporary geomorphology must also be considered in restoration efforts. This chapter synthesizes available information to compare floodplain function and needed management strategies in two extensive reaches (upper impounded and lower free-flowing) of the Mississippi River, USA. The upper impounded reach is the 523-km reach from about Minneapolis, Minnesota to Clinton, Iowa. This reach has been impounded and channelized for navigation. Mean annual water-level fluctuation ranges from 1 to 2 m in the navigation pools in this reach. Floodplain environmental conditions that affect nitrogen cycling and fish production vary seasonally and longitudinally within and among navigation pools. Significant issues affecting ecological services include sedimentation, constrained water level fluctuations, island erosion and seasonal hypoxia. The lower free-flowing reach, the 1570-km reach from the confluence of the Ohio and Mississippi rivers to the Gulf of Mexico, has no dams and average annual fluctuations of 7 m throughout most of the reach. Despite the substantial flood pulse, floodplain inundation is often brief and may not occur annually. Significant issues affecting floodplain ecological function are the short duration and thermal asynchrony of the flood pulse, sedimentation and loss of connection between the river channel and permanent/semi-permanent floodplain water bodies due to channel incision. Needs and strategies for floodplain enhancement to increase ecological services, particularly nitrogen cycling and fish production, differ along the longitudinal gradient of the Mississippi River and provide informative contrasts to guide floodplain management. Prediction of the effects of climate change on this system will be complicated by the magnitude of the watershed that encompasses 41 % of the continental USA and multiple climatic regions.

[Pollution distribution and potential ecological risk assessment of heavy metals in sediments from the different eastern dredging regions of Lake Taihu].

PubMed

Mao, Zhi-Gang; Gu, Xiao-Hong; Lu, Xiao-Ming; Zeng, Qing-Fei; Gu, Xian-Kun; Li, Xu-Guang

2014-01-01

In order to investigate the distribution characteristics of nutrients and heavy metals in sediments from different eastern dredging regions of Lake Taihu, the surface and core sediment samples at 5 sites (in East Taihu Lake and Xukou Bay) were collected in 2012. Contents of nutrients (TOC, TN and TP) and heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb and Zn) in the sediments were measured and the pollution degrees of heavy metals were evaluated with the potential ecological risk method. The results showed that the heavy metal contents in Xukou Bay were generally higher than those in East Taihu Lake, whereas the nutrients contents showed the reverse trend. There were significant differences between the phytoplankton-dominated and culture lake regions. The concentrations of both nutrients and heavy metals decreased with increasing profile depth. Moreover, the contents of nutrients and heavy metals in the sediments of all dredged areas were lower than those in the un-dredged areas, suggesting that dredging may be a useful approach for decreasing nutrients and heavy metals loading in sediments, but its effectiveness decreased with time. Significant positive correlations were found among different heavy metals and nutrients, indicating that they were from the same pollution source. The Hakanson potential ecological risk index was applied for assessing the status of sediment heavy metal enrichment and the result indicated that sediment dredging could reduce the extent of potential ecological risk. The risk index in different sites followed the order: X1 > D1 > D3 > X2 > D2, while the risk index in site X1 of Xukou Bay was higher than that in site D1 of East Taihu Lake. And the comprehensive ecological risk grades in sites X1 and D1 were in the moderate range, while the sites D2, D3 and X2 were low.

Interspecies physiological variation as a tool for cross-species assessments of global warming-induced endangerment: validation of an intrinsic determinant of macroecological and phylogeographic structure.

PubMed

Bernardo, Joseph; Ossola, Ryan J; Spotila, James; Crandall, Keith A

2007-12-22

Global warming is now recognized as the dominant threat to biodiversity because even protected populations and habitats are susceptible. Nonetheless, current criteria for evaluating species' relative endangerment remain purely ecological, and the accepted conservation strategies of habitat preservation and population management assume that species can mount ecological responses if afforded protection. The insidious threat from climate change is that it will attenuate or preclude ecological responses by species that are physiologically constrained; yet, quantitative, objective criteria for assessing relative susceptibility of diverse taxa to warming-induced stress are wanting. We explored the utility of using interspecies physiological variation for this purpose by relating species' physiological phenotypes to landscape patterns of ecological and genetic exchange. Using a salamander model system in which ecological, genetic and physiological diversity are well characterized, we found strong quantitative relationships of basal metabolic rates (BMRs) to both macroecological and phylogeographic patterns, with decreasing BMR leading to dispersal limitation (small contemporary ranges with marked phylogeographic structure). Measures of intrinsic physiological tolerance, which vary systematically with macroecological and phylogeographic patterns, afford objective criteria for assessing endangerment across a wide range of species and should be incorporated into conservation assessment criteria that currently rely exclusively upon ecological predictors.

High proportion of smaller ranged hummingbird species coincides with ecological specialization across the Americas

PubMed Central

Martín González, Ana M.; Maruyama, Pietro K.; Sandel, Brody; Vizentin-Bugoni, Jeferson; Schleuning, Matthias; Abrahamczyk, Stefan; Alarcón, Ruben; Araujo, Andréa C.; Araújo, Francielle P.; Mendes de Azevedo, Severino; Baquero, Andrea C.; Cotton, Peter A.; Ingversen, Tanja Toftemark; Kohler, Glauco; Lara, Carlos; Guedes Las-Casas, Flor Maria; Machado, Adriana O.; Machado, Caio Graco; Maglianesi, María Alejandra; Moura, Alan Cerqueira; Nogués-Bravo, David; Oliveira, Genilda M.; Oliveira, Paulo E.; Ornelas, Juan Francisco; Rodrigues, Licléia da Cruz; Rosero-Lasprilla, Liliana; Rui, Ana Maria; Sazima, Marlies; Timmermann, Allan; Varassin, Isabela Galarda; Wang, Zhiheng; Watts, Stella; Fjeldså, Jon; Svenning, Jens-Christian; Rahbek, Carsten; Dalsgaard, Bo

2016-01-01

Ecological communities that experience stable climate conditions have been speculated to preserve more specialized interspecific associations and have higher proportions of smaller ranged species (SRS). Thus, areas with disproportionally large numbers of SRS are expected to coincide geographically with a high degree of community-level ecological specialization, but this suggestion remains poorly supported with empirical evidence. Here, we analysed data for hummingbird resource specialization, range size, contemporary climate, and Late Quaternary climate stability for 46 hummingbird–plant mutualistic networks distributed across the Americas, representing 130 hummingbird species (ca 40% of all hummingbird species). We demonstrate a positive relationship between the proportion of SRS of hummingbirds and community-level specialization, i.e. the division of the floral niche among coexisting hummingbird species. This relationship remained strong even when accounting for climate, furthermore, the effect of SRS on specialization was far stronger than the effect of specialization on SRS, suggesting that climate largely influences specialization through species' range-size dynamics. Irrespective of the exact mechanism involved, our results indicate that communities consisting of higher proportions of SRS may be vulnerable to disturbance not only because of their small geographical ranges, but also because of their high degree of specialization. PMID:26842573

The ecological impact assessment of a proposed road development (the Slovak approach)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Igondova, Erika, E-mail: erika.igondova@gmail.com; Pavlickova, Katarina, E-mail: pavlickova60@gmail.com; Majzlan, Oto, E-mail: majzlan@fns.uniba.sk

The construction of roads is one of the most widespread forms of natural landscape modification. Over the last 20 years, dozens of road constructions have been assessed in Slovakia, which makes it possible to talk about methodological positives and negatives. A special feature of Slovakia is that many planned or renovated roads are located in protected areas or are in contact with them (including Natura 2000 sites). Therefore, it is important to understand the scope of the roads' ecological impacts and find ways for their appropriate evaluation and incorporation into the Environmental Impact Assessment process. For this reason, the Ecologicalmore » Impact Assessment methodology can be used as a basis for our research, which consists of three stages. In the first stage (scoping), a buffer circumventing the proposed road is created to determine the area for impact prediction and evaluation. Subsequently, the landscape structure and baseline landscape conditions are discussed, a map of current landscape structure is created and the current ecological status of the affected area is calculated. In the second stage (the evaluation of ecological resources), important ecological parts of the landscape are delineated. This step is based on the importance of previous information and its vulnerability, and leads to the mapping of the road ecological impact zone. In the third stage (impact assessment), important ecological parts are spatially correlated with the proposed road construction. Finally, the significance of ecological impacts of the activity is evaluated by applying specific criteria (duration, reversibility, magnitude, size and road ecological impact zone significance). A scale is proposed for each criterion to evaluate the total significance of impacts. In this way, detailed significant ecological impacts can be found which will help lead to proposed correct mitigation measures and a post-project analysis. - Highlights: • This paper proposes a methodology for the EcIA of road construction. • It tries to understand the spatial structure and configuration of landscape elements. • The most important ecological parts within the territory are identified. • The total significance of ecological receptors is evaluated by applying criteria.« less

Cumulative effects of climate and landscape change drive spatial distribution of Rocky Mountain wolverine (Gulo gulo L.).

PubMed

Heim, Nicole; Fisher, Jason T; Clevenger, Anthony; Paczkowski, John; Volpe, John

2017-11-01

Contemporary landscapes are subject to a multitude of human-derived stressors. Effects of such stressors are increasingly realized by population declines and large-scale extirpation of taxa worldwide. Most notably, cumulative effects of climate and landscape change can limit species' local adaptation and dispersal capabilities, thereby reducing realized niche space and range extent. Resolving the cumulative effects of multiple stressors on species persistence is a pressing challenge in ecology, especially for declining species. For example, wolverines ( Gulo gulo L.) persist on only 40% of their historic North American range. While climate change has been shown to be a mechanism of range retractions, anthropogenic landscape disturbance has been recently implicated. We hypothesized these two interact to effect declines. We surveyed wolverine occurrence using camera trapping and genetic tagging at 104 sites at the wolverine range edge, spanning a 15,000 km 2 gradient of climate, topographic, anthropogenic, and biotic variables. We used occupancy and generalized linear models to disentangle the factors explaining wolverine distribution. Persistent spring snow pack-expected to decrease with climate change-was a significant predictor, but so was anthropogenic landscape change. Canid mesocarnivores, which we hypothesize are competitors supported by anthropogenic landscape change, had comparatively weaker effect. Wolverine population declines and range shifts likely result from climate change and landscape change operating in tandem. We contend that similar results are likely for many species and that research that simultaneously examines climate change, landscape change, and the biotic landscape is warranted. Ecology research and species conservation plans that address these interactions are more likely to meet their objectives.

Evaluation of Ecological Environment Security in Contiguous Poverty Alleviation Area of Sichuan Province

NASA Astrophysics Data System (ADS)

Xian, W.; Chen, Y.; Chen, J.; Luo, X.; Shao, H.

2018-04-01

According to the overall requirements of ecological construction and environmental protection, rely on the national key ecological engineering, strengthen ecological environmental restoration and protection, improve forest cover, control soil erosion, construct important ecological security barrier in poor areas, inhibit poverty alleviation through ecological security in this area from environmental damage to the vicious cycle of poverty. Obviously, the dynamic monitoring of ecological security in contiguous destitute areas of Sichuan province has a policy sense of urgency and practical significance. This paper adopts RS technology and GIS technology to select the Luhe region of Jinchuan county and Ganzi prefecture as the research area, combined with the characteristics of ecological environment in poor areas, the impact factors of ecological environment are determined as land use type, terrain slope, vegetation cover, surface water, soil moisture and other factors. Using the ecological environmental safety assessment model, the ecological environment safety index is calculated. According to the index, the ecological environment safety of the research area is divided into four levels. The ecological environment safety classification map of 1990 in 2009 is obtained. It can be seen that with the human modern life and improve their economic level, the surrounding environment will be destroyed, because the research area ecological environment is now in good, the ecological environment generally tends to be stable. We should keep its ecological security good and improve local economic income. The relationship between ecological environmental security and economic coordinated development in poor areas has very important strategic significance.

The behavioral ecology of sympatric African apes: implications for understanding fossil hominoid ecology.

PubMed

Stanford, Craig B

2006-01-01

The behavioral ecology of the great apes is key evidence used in the reconstruction of the behavior of extinct ape and hominid taxa. Chimpanzees and gorillas have been studied in detail in the wild, and some studies of their behavioral ecology in sympatry have also been been carried out. Although the two ape species have divergent behavior and ecology in important respects, recent studies have shown that the interspecific differences are not as stark as previously thought and subsequently urge new consideration of how they share forest resources when sympatric. These new data require re-examination of assumptions about key aspects of chimpanzee-gorilla ecological divergence, such as diet, ranging and nesting patterns, and the mating system. Diet is a key component of the species' adaptive complexes that facilitates avoidance of direct competition from the other. While the nutritional basis for chimpanzee food choice remains unclear and no doubt varies from site to site, this species is a ripe fruit specialist and ranges farther during periods of ripe fruit scarcity. Gorillas in the same habitat also feed on ripe fruit when widely available, but fall back onto fibrous plant foods during lean periods. The inclusion of animal protein in the diet of the chimpanzees and its absence in that of the gorillas also distinguish the species ecologically. It may also offer clues to aspects of ecological divergence among early members of the hominid phylogeny. The paper concludes by suggesting likely characteristics of sympatric associations of Pliocene hominids, based on field data from extant sympatric apes.

Conclusions about Niche Expansion in Introduced Impatiens walleriana Populations Depend on Method of Analysis

PubMed Central

Mandle, Lisa; Warren, Dan L.; Hoffmann, Matthias H.; Peterson, A. Townsend; Schmitt, Johanna; von Wettberg, Eric J.

2010-01-01

Determining the degree to which climate niches are conserved across plant species' native and introduced ranges is valuable to developing successful strategies to limit the introduction and spread of invasive plants, and also has important ecological and evolutionary implications. Here, we test whether climate niches differ between native and introduced populations of Impatiens walleriana, globally one of the most popular horticultural species. We use approaches based on both raw climate data associated with occurrence points and ecological niche models (ENMs) developed with Maxent. We include comparisons of climate niche breadth in both geographic and environmental spaces, taking into account differences in available habitats between the distributional areas. We find significant differences in climate envelopes between native and introduced populations when comparing raw climate variables, with introduced populations appearing to expand into wetter and cooler climates. However, analyses controlling for differences in available habitat in each region do not indicate expansion of climate niches. We therefore cannot reject the hypothesis that observed differences in climate envelopes reflect only the limited environments available within the species' native range in East Africa. Our results suggest that models built from only native range occurrence data will not provide an accurate prediction of the potential for invasiveness if applied to areas containing a greater range of environmental combinations, and that tests of niche expansion may overestimate shifts in climate niches if they do not control carefully for environmental differences between distributional areas. PMID:21206912

A systematic review of US rangeland social science

USDA-ARS?s Scientific Manuscript database

Rangeland science aims to create knowledge to sustain rangeland social-ecological systems over the long term. Range science has made substantial progress on understanding ecological dynamics of rangeland systems and the management practices that sustain them, and these findings have been systematica...

Performance of National Maps of Watershed Integrity at Watershed Scales

EPA Science Inventory

Watershed integrity, the capacity of a watershed to support and maintain ecological processes essential to the sustainability of services provided to society, can be influenced by a range of landscape and in-stream factors. Ecological response data from four intensively monitored...

Do Contaminants Originating from State-of-the-Art Treated Wastewater Impact the Ecological Quality of Surface Waters?

PubMed Central

Stalter, Daniel; Magdeburg, Axel; Quednow, Kristin; Botzat, Alexandra; Oehlmann, Jörg

2013-01-01

Since the 1980s, advances in wastewater treatment technology have led to considerably improved surface water quality in the urban areas of many high income countries. However, trace concentrations of organic wastewater-associated contaminants may still pose a key environmental hazard impairing the ecological quality of surface waters. To identify key impact factors, we analyzed the effects of a wide range of anthropogenic and environmental variables on the aquatic macroinvertebrate community. We assessed ecological water quality at 26 sampling sites in four urban German lowland river systems with a 0–100% load of state-of-the-art biological activated sludge treated wastewater. The chemical analysis suite comprised 12 organic contaminants (five phosphor organic flame retardants, two musk fragrances, bisphenol A, nonylphenol, octylphenol, diethyltoluamide, terbutryn), 16 polycyclic aromatic hydrocarbons, and 12 heavy metals. Non-metric multidimensional scaling identified organic contaminants that are mainly wastewater-associated (i.e., phosphor organic flame retardants, musk fragrances, and diethyltoluamide) as a major impact variable on macroinvertebrate species composition. The structural degradation of streams was also identified as a significant factor. Multiple linear regression models revealed a significant impact of organic contaminants on invertebrate populations, in particular on Ephemeroptera, Plecoptera, and Trichoptera species. Spearman rank correlation analyses confirmed wastewater-associated organic contaminants as the most significant variable negatively impacting the biodiversity of sensitive macroinvertebrate species. In addition to increased aquatic pollution with organic contaminants, a greater wastewater fraction was accompanied by a slight decrease in oxygen concentration and an increase in salinity. This study highlights the importance of reducing the wastewater-associated impact on surface waters. For aquatic ecosystems in urban areas this would lead to: (i) improvement of the ecological integrity, (ii) reduction of biodiversity loss, and (iii) faster achievement of objectives of legislative requirements, e.g., the European Water Framework Directive. PMID:23593263

Do contaminants originating from state-of-the-art treated wastewater impact the ecological quality of surface waters?

PubMed

Stalter, Daniel; Magdeburg, Axel; Quednow, Kristin; Botzat, Alexandra; Oehlmann, Jörg

2013-01-01

Since the 1980s, advances in wastewater treatment technology have led to considerably improved surface water quality in the urban areas of many high income countries. However, trace concentrations of organic wastewater-associated contaminants may still pose a key environmental hazard impairing the ecological quality of surface waters. To identify key impact factors, we analyzed the effects of a wide range of anthropogenic and environmental variables on the aquatic macroinvertebrate community. We assessed ecological water quality at 26 sampling sites in four urban German lowland river systems with a 0-100% load of state-of-the-art biological activated sludge treated wastewater. The chemical analysis suite comprised 12 organic contaminants (five phosphor organic flame retardants, two musk fragrances, bisphenol A, nonylphenol, octylphenol, diethyltoluamide, terbutryn), 16 polycyclic aromatic hydrocarbons, and 12 heavy metals. Non-metric multidimensional scaling identified organic contaminants that are mainly wastewater-associated (i.e., phosphor organic flame retardants, musk fragrances, and diethyltoluamide) as a major impact variable on macroinvertebrate species composition. The structural degradation of streams was also identified as a significant factor. Multiple linear regression models revealed a significant impact of organic contaminants on invertebrate populations, in particular on Ephemeroptera, Plecoptera, and Trichoptera species. Spearman rank correlation analyses confirmed wastewater-associated organic contaminants as the most significant variable negatively impacting the biodiversity of sensitive macroinvertebrate species. In addition to increased aquatic pollution with organic contaminants, a greater wastewater fraction was accompanied by a slight decrease in oxygen concentration and an increase in salinity. This study highlights the importance of reducing the wastewater-associated impact on surface waters. For aquatic ecosystems in urban areas this would lead to: (i) improvement of the ecological integrity, (ii) reduction of biodiversity loss, and (iii) faster achievement of objectives of legislative requirements, e.g., the European Water Framework Directive.

Long-term ecological data for conservation: Range change in the black-billed capercaillie (Tetrao urogalloides) in northeast China (1970s-2070s).

PubMed

Yang, Li; Zhang, Chao; Chen, Minhao; Li, Jingxin; Yang, Lei; Huo, Zhaomin; Ahmad, Shahid; Luan, Xiaofeng

2018-04-01

Long-term ecological data can be an effective tool to help ecologists integrate future projections with historical contexts and provide unique insights into the long-term dynamics of endangered species. However, hampered by data limitations, including incomplete and spatially biased data, relatively few studies have used multidecadal datasets or have examined changes in biogeography from a historical perspective. The black-billed capercaillie ( Tetrao urogalloides ) is a large capercaillie (classified as Least Concern [LC] on the IUCN red list) that has undergone a dramatic decline in population during the late 20th century and is considered endangered. Its conservation status is pessimistic, and the species requires immediate protection. Therefore, we supplemented a historical dataset to identify changes in this bird's range and population in northeast China over the long term. The study area spanned Heilongjiang Province, Jilin Province, and the northeast corner of Inner Mongolia in northeast China. We integrated an ecological niche model (BIOMOD2) with long-term ecological data on this species to estimate the magnitude of change in distribution over time. Our results revealed a 35.25% reduction in the current distribution of this species compared to their potential distribution in the 1970s. This decline is expected to continue under climate change. For example, the future range loss was estimated to be 38.79 ± 0.22% (8.64-90.19%), and the actual state could be worse, because the baseline range of the model was greater than the real range in the 2000s, showing a 12.39% overestimation. To overcome this poor outlook, a conservation strategy should be established in sensitive areas, including the southwestern Greater Khingan Mountains and northern Lesser Khingan Mountains. Actions that should be considered include field investigations, establishing a monitor network, designing ecological corridors, and cooperating with local inhabitants, governments, and conservation biologists to improve the conservation of the black-billed capercaillie.

[Pollution Characteristics and Ecological Risk of PBDEs in Water and Sediment from an Electronic Waste Dismantling Area in Taizhou].

PubMed

Chen, Xiang-ping; Peng, Bao-qi; Lü, Su-ping; Chen, Qiang; Zhang, Yong; Huang, Chang-jiang; Dong, Qiao-xiang

2016-05-15

An e-waste dismantling industrial park of Taizhou was selected as the sampling center, within a radius of 16 km, and a total of 30 sampling sites were designed in three circles as follows: C (3 km), S (5-10 km) and R (10-16 km). Pollution characteristics and ecological risk of polybrominated diphenyl ethers (PBDEs) in water and sediments were investigated. The concentrations of PBDEs in water ranged from 9.4 to 57.2 ng · L⁻¹, with a mean value of 25.9 ng · L⁻¹; and 3.7 to 38,775 ng · g⁻¹, with an average of 2 779 ng · g⁻¹ in sediments. BDE-209 was the predominant congener. The spatial distribution patterns of PBDE levels in water and sediment were both in the following order: C > S > R. Furthermore, the concentrations of PBDEs in sediments showed significant negative correlation against the distance from the industrial park (P < 0.01). Compared with other regions around the world, the PBDEs contamination was more serious in the area, which indicated that e-waste dismantling activity was one of the significant sources for PBDEs pollution. It was estimated that a total of 30. 7 t PBDEs (including 28. 9 t BDE- 209) was discharged into surrounding environment as a result of dismantling industrial activities in last 40 years. A preliminary ecological risk assessment for PBDEs in water and sediments was conducted by hazard quotient method. The results demonstrated that the Penta-BDEs in the center of e-waste dismantling area ( a radius of 1.5 km) was at particularly high risk level and could cause serious influence on the ecological safety and human health.

Ecological factors associated with European bat lyssavirus seroprevalence in spanish bats.

PubMed

Serra-Cobo, Jordi; López-Roig, Marc; Seguí, Magdalena; Sánchez, Luisa Pilar; Nadal, Jacint; Borrás, Miquel; Lavenir, Rachel; Bourhy, Hervé

2013-01-01

Bats have been proposed as major reservoirs for diverse emerging infectious viral diseases, with rabies being the best known in Europe. However, studies exploring the ecological interaction between lyssaviruses and their natural hosts are scarce. This study completes our active surveillance work on Spanish bat colonies that began in 1992. Herein, we analyzed ecological factors that might affect the infection dynamics observed in those colonies. Between 2001 and 2011, we collected and tested 2,393 blood samples and 45 dead bats from 25 localities and 20 bat species. The results for dead confirmed the presence of EBLV-1 RNA in six species analyzed (for the first time in Myotis capaccinii). Samples positive for European bat lyssavirus-1 (EBLV-1)-neutralizing antibodies were detected in 68% of the localities sampled and in 13 bat species, seven of which were found for the first time (even in Myotis daubentonii, a species to date always linked to EBLV-2). EBLV-1 seroprevalence (20.7%) ranged between 11.1 and 40.2% among bat species and seasonal variation was observed, with significantly higher antibody prevalence in summer (July). EBLV-1 seroprevalence was significantly associated with colony size and species richness. Higher seroprevalence percentages were found in large multispecific colonies, suggesting that intra- and interspecific contacts are major risk factors for EBLV-1 transmission in bat colonies. Although bat-roosting behavior strongly determines EBLV-1 variability, we also found some evidence that bat phylogeny might be involved in bat-species seroprevalence. The results of this study highlight the importance of life history and roost ecology in understanding EBLV-1-prevalence patterns in bat colonies and also provide useful information for public health officials.

Ecological Factors Associated with European Bat Lyssavirus Seroprevalence in Spanish Bats

PubMed Central

Serra-Cobo, Jordi; López-Roig, Marc; Seguí, Magdalena; Sánchez, Luisa Pilar; Nadal, Jacint; Borrás, Miquel; Lavenir, Rachel; Bourhy, Hervé

2013-01-01

Bats have been proposed as major reservoirs for diverse emerging infectious viral diseases, with rabies being the best known in Europe. However, studies exploring the ecological interaction between lyssaviruses and their natural hosts are scarce. This study completes our active surveillance work on Spanish bat colonies that began in 1992. Herein, we analyzed ecological factors that might affect the infection dynamics observed in those colonies. Between 2001 and 2011, we collected and tested 2,393 blood samples and 45 dead bats from 25 localities and 20 bat species. The results for dead confirmed the presence of EBLV-1 RNA in six species analyzed (for the first time in Myotis capaccinii). Samples positive for European bat lyssavirus-1 (EBLV-1)–neutralizing antibodies were detected in 68% of the localities sampled and in 13 bat species, seven of which were found for the first time (even in Myotis daubentonii, a species to date always linked to EBLV-2). EBLV-1 seroprevalence (20.7%) ranged between 11.1 and 40.2% among bat species and seasonal variation was observed, with significantly higher antibody prevalence in summer (July). EBLV-1 seroprevalence was significantly associated with colony size and species richness. Higher seroprevalence percentages were found in large multispecific colonies, suggesting that intra- and interspecific contacts are major risk factors for EBLV-1 transmission in bat colonies. Although bat-roosting behavior strongly determines EBLV-1 variability, we also found some evidence that bat phylogeny might be involved in bat-species seroprevalence. The results of this study highlight the importance of life history and roost ecology in understanding EBLV-1–prevalence patterns in bat colonies and also provide useful information for public health officials. PMID:23700480

Coastal urban lighting has ecological consequences for multiple trophic levels under the sea.

PubMed

Bolton, D; Mayer-Pinto, M; Clark, G F; Dafforn, K A; Brassil, W A; Becker, A; Johnston, E L

2017-01-15

Urban land and seascapes are increasingly exposed to artificial lighting at night (ALAN), which is a significant source of light pollution. A broad range of ecological effects are associated with ALAN, but the changes to ecological processes remain largely unstudied. Predation is a key ecological process that structures assemblages and responds to natural cycles of light and dark. We investigated the effect of ALAN on fish predatory behaviour, and sessile invertebrate prey assemblages. Over 21days fish and sessile assemblages were exposed to 3 light treatments (Day, Night and ALAN). An array of LED spotlights was installed under a wharf to create the ALAN treatments. We used GoPro cameras to film during the day and ALAN treatments, and a Dual frequency IDentification SONar (DIDSON) to film during the night treatments. Fish were most abundant during unlit nights, but were also relatively sedentary. Predatory behaviour was greatest during the day and under ALAN than at night, suggesting that fish are using structures for non-feeding purposes (e.g. shelter) at night, but artificial light dramatically increases their predatory behaviour. Altered predator behaviour corresponded with structural changes to sessile prey assemblages among the experimental lighting treatments. We demonstrate the direct effects of artificial lighting on fish behaviour and the concomitant indirect effects on sessile assemblage structure. Current and future projected use of artificial lights has the potential to significantly affect predator-prey interactions in marine systems by altering habitat use for both predators and prey. However, developments in lighting technology are a promising avenue for mitigation. This is among the first empirical evidence from the marine system on how ALAN can directly alter predation, a fundamental ecosystem process, and have indirect trophic consequences. Copyright © 2016 Elsevier B.V. All rights reserved.

Characteristics of the Cross-Sectional Vorticity of the Natural Spawning Grounds of Schizothorax prenanti and a Vague-Set Similarity Model for Ecological Restoration

PubMed Central

Liu, Ming-Yang; Zhang, Ling-Lei; Li, Jia; Li, Yong; Li, Nan; Chen, Ming-Qian

2015-01-01

Schizothorax prenanti is an endemic fish in the mountain rivers of southwestern China with unique protection value. To further explore the vortex motion of hydraulic habitats, which is closely related to the fish breeding process, the cross-sectional vorticity was used to evaluate the hydraulic conditions of the natural spawning habitat of S. prenanti. A coupled level-set and volume-of-fluid (CLSVOF) three-dimensional (3D) model was applied to simulate the hydraulic habitat of the Weimen reach, a typical natural spawning ground for S. prenanti in the upper Yangtze River. The model was used in conjunction with the Wilcoxon rank sum test to distinguish the distributions of vertical vorticity in spawning and non-spawning reaches. Statistical analysis revealed that the cross-sectional vorticity in spawning reaches was significantly greater than in non-spawning reaches, with likely biological significance in the spawning process. The range of cross-sectional mean values of vorticity was 0.17 s-1–0.35 s-1 in areas with concentrated fish sperm and eggs; the minimum value was 0.17 s-1, and the majority of values were greater than 0.26 s-1. Based on this study, a vague-set similarity model was used to assess the effectiveness of ecological restoration by evaluating the similarity of the cross-sectional vorticity of the natural spawning reach and rehabilitated spawning reach after implementing ecological restoration measures. The outcome might provide a theoretical basis for the recovery of damaged S. prenanti spawning grounds and act as an important complement for the assessment of recovery effectiveness and as a useful reference for the coordination of ecological water use with the demands of hydraulic and hydropower engineering. PMID:26317847

Quantifying the drivers of water security risks in a complex northern deltaic ecosystem

NASA Astrophysics Data System (ADS)

Rokaya, P.; Wheater, H. S.; Lindenschmidt, K. E.

2017-12-01

There is still a need for improved, scientific evaluations of potential impacts of a changing flow regime on the northern deltaic ecosystems. This is particularly the case for the Slave River Delta (SRD) which is believed to be drying. Although streamflow regulation in the major headwater tributary and climate change have been presented as major contributors of hydro-ecological change in the SRD, a wide range of drivers such as large scale water withdrawal, land-use change and flow modulation by the upstream delta (i.e. the Peace-Athabasca Delta) could pose challenges to water security. However, limited numbers of studies with inadequate data make it difficult to understand the principal drivers of the hydro-ecological changes. One of the least explored drivers is the upstream delta which attenuates the peak flows, retains the floodwater and reduces the downstream flood intensity. This can have significant impact on the productivity and ecological diversity of the SRD, which are governed by water and nutrient-rich sediment supplied during flood events. Thus, the Slave River basin presents a complex river system where multiple drivers are in interplay resulting in a different (new) flow regime. However, any river flow alterations could significantly affect this ecologically and socio-economically delicate ecosystem. In this study, we investigate the critical challenges related to water security in a complex deltaic ecosystem, quantifying the relative impacts of climate change, human interventions and the upstream delta on the SRD. We demonstrate that the sustainability issues of northern deltaic systems are dynamic, complex and multi-faceted, and require an understanding of intricate relationships and feedback mechanisms between human and natural systems.

Bioprotection and disturbance: Seaweed, microclimatic stability and conditions for mechanical weathering in the intertidal zone

NASA Astrophysics Data System (ADS)

Coombes, Martin A.; Naylor, Larissa A.; Viles, Heather A.; Thompson, Richard C.

2013-11-01

As well as their destructive roles, plants, animals and microorganisms contribute to geomorphology and ecology via direct and indirect bioprotection, which can reduce weathering and erosion. For example, indirect bioprotection can operate via biotic influences on microclimate whereby physical decay processes associated with fluctuations in temperature and moisture (salt crystallization, thermal fatigue and wetting-drying), are limited. In the intertidal zone, the spatial and temporal distribution of macroalgae (seaweeds) is patchy, related to physical and ecological conditions for colonization and growth, and the nature and frequency of natural and anthropogenic disturbance. We examined the influence of seaweed canopies (Fucus spp.) on near-surface microclimate and, by implication, on conditions for mechanical rock decay and under-canopy ecology. Monitoring on hard artificial coastal structures in South West England, UK, built from limestone and concrete showed that both the range and maxima of daily summertime temperatures were significantly lower, by an average of 56% and 25%, respectively, in areas colonized by seaweed compared to experimentally cleared areas. Short-term microclimatic variability (minutes-hours) was also significantly reduced, by an average of 78% for temperature and 71% for humidity, under algal canopies during low-tide events. Using seaweed as an example, we develop a conceptual model of the relationship between biological cover and microclimate in the intertidal zone. Disturbance events that remove or drastically reduce seaweed cover mediate shifts between relatively stable and unstable states with respect to mechanical decay and ecological stress associated with heat and desiccation. In urban coastal environments where disturbance may be frequent, facilitating the establishment and recovery of canopy-forming species on rocks and engineered structures could enhance the durability of construction materials as well as support conservation, planning and policy targets for biodiversity enhancement.

Comparisons of fish species traits from small streams to large rivers

USGS Publications Warehouse

Goldstein, R.M.; Meador, M.R.

2004-01-01

To examine the relations between fish community function and stream size, we classified 429 lotic freshwater fish species based on multiple categories within six species traits: (1) substrate preference, (2) geomorphic preference, (3) trophic ecology, (4) locomotion morphology, (5) reproductive strategy, and (6) stream size preference. Stream size categories included small streams, small, medium, and large rivers, and no size preference. The frequencies of each species trait category were determined for each stream size category based on life history information from the literature. Cluster analysis revealed the presence of covarying groups of species trait categories. One cluster (RUN) included the traits of planktivore and herbivore feeding ecology, migratory reproductive behavior and broadcast spawning, preferences for main-channel habitats, and a lack of preferences for substrate type. The frequencies of classifications for the RUN cluster varied significantly across stream size categories (P = 0.009), being greater for large rivers than for small streams and rivers. Another cluster (RIFFLE) included the traits of invertivore feeding ecology, simple nester reproductive behavior, a preference for riffles, and a preference for bedrock, boulder, and cobble-rubble substrate. No significant differences in the frequency of classifications among stream size categories were detected for the RIFFLE cluster (P = 0.328). Our results suggest that fish community function is structured by large-scale differences in habitat and is different for large rivers than for small streams and rivers. Our findings support theoretical predictions of variation in species traits among stream reaches based on ecological frameworks such as landscape filters, habitat templates, and the river continuum concept. We believe that the species trait classifications presented here provide an opportunity for further examination of fish species' relations to physical, chemical, and biological factors in lotic habitats ranging from small streams to large rivers.

Curricula without Boundaries: Developing an Ecological Connection for Higher Education Curricula

ERIC Educational Resources Information Center

Wang, Chia-Ling

2014-01-01

This study was conducted to address the concept of higher education curricula and its practice from an ecological perspective. First, the significance of ecology is investigated based on two streams of thought; the ecological concept of the university proposed by Ronald Barnett; and the text, "The Three Ecologies" authored by the Italian…

Does detection range matter for inferring social networks in a benthic shark using acoustic telemetry?

PubMed Central

Bass, Nathan Charles; Guttridge, Tristan L.; Day, Joanna; Brown, Culum

2017-01-01

Accurately estimating contacts between animals can be critical in ecological studies such as examining social structure, predator–prey interactions or transmission of information and disease. While biotelemetry has been used successfully for such studies in terrestrial systems, it is still under development in the aquatic environment. Acoustic telemetry represents an attractive tool to investigate spatio-temporal behaviour of marine fish and has recently been suggested for monitoring underwater animal interactions. To evaluate the effectiveness of acoustic telemetry in recording interindividual contacts, we compared co-occurrence matrices deduced from three types of acoustic receivers varying in detection range in a benthic shark species. Our results demonstrate that (i) associations produced by acoustic receivers with a large detection range (i.e. Vemco VR2W) were significantly different from those produced by receivers with smaller ranges (i.e. Sonotronics miniSUR receivers and proximity loggers) and (ii) the position of individuals within their network, or centrality, also differed. These findings suggest that acoustic receivers with a large detection range may not be the best option to represent true social networks in the case of a benthic marine animal. While acoustic receivers are increasingly used by marine ecologists, we recommend users first evaluate the influence of detection range to depict accurate individual interactions before using these receivers for social or predator–prey studies. We also advocate for combining multiple receiver types depending on the ecological question being asked and the development of multi-sensor tags or testing of new automated proximity loggers, such as the Encounternet system, to improve the precision and accuracy of social and predator–prey interaction studies. PMID:28989756

Personality in the cockroach Diploptera punctata: Evidence for stability across developmental stages despite age effects on boldness.

PubMed

Stanley, Christina R; Mettke-Hofmann, Claudia; Preziosi, Richard F

2017-01-01

Despite a recent surge in the popularity of animal personality studies and their wide-ranging associations with various aspects of behavioural ecology, our understanding of the development of personality over ontogeny remains poorly understood. Stability over time is a central tenet of personality; ecological pressures experienced by an individual at different life stages may, however, vary considerably, which may have a significant effect on behavioural traits. Invertebrates often go through numerous discrete developmental stages and therefore provide a useful model for such research. Here we test for both differential consistency and age effects upon behavioural traits in the gregarious cockroach Diploptera punctata by testing the same behavioural traits in both juveniles and adults. In our sample, we find consistency in boldness, exploration and sociality within adults whilst only boldness was consistent in juveniles. Both boldness and exploration measures, representative of risk-taking behaviour, show significant consistency across discrete juvenile and adult stages. Age effects are, however, apparent in our data; juveniles are significantly bolder than adults, most likely due to differences in the ecological requirements of these life stages. Size also affects risk-taking behaviour since smaller adults are both bolder and more highly explorative. Whilst a behavioural syndrome linking boldness and exploration is evident in nymphs, this disappears by the adult stage, where links between other behavioural traits become apparent. Our results therefore indicate that differential consistency in personality can be maintained across life stages despite age effects on its magnitude, with links between some personality traits changing over ontogeny, demonstrating plasticity in behavioural syndromes.

Personality in the cockroach Diploptera punctata: Evidence for stability across developmental stages despite age effects on boldness

PubMed Central

Mettke-Hofmann, Claudia; Preziosi, Richard F.

2017-01-01

Despite a recent surge in the popularity of animal personality studies and their wide-ranging associations with various aspects of behavioural ecology, our understanding of the development of personality over ontogeny remains poorly understood. Stability over time is a central tenet of personality; ecological pressures experienced by an individual at different life stages may, however, vary considerably, which may have a significant effect on behavioural traits. Invertebrates often go through numerous discrete developmental stages and therefore provide a useful model for such research. Here we test for both differential consistency and age effects upon behavioural traits in the gregarious cockroach Diploptera punctata by testing the same behavioural traits in both juveniles and adults. In our sample, we find consistency in boldness, exploration and sociality within adults whilst only boldness was consistent in juveniles. Both boldness and exploration measures, representative of risk-taking behaviour, show significant consistency across discrete juvenile and adult stages. Age effects are, however, apparent in our data; juveniles are significantly bolder than adults, most likely due to differences in the ecological requirements of these life stages. Size also affects risk-taking behaviour since smaller adults are both bolder and more highly explorative. Whilst a behavioural syndrome linking boldness and exploration is evident in nymphs, this disappears by the adult stage, where links between other behavioural traits become apparent. Our results therefore indicate that differential consistency in personality can be maintained across life stages despite age effects on its magnitude, with links between some personality traits changing over ontogeny, demonstrating plasticity in behavioural syndromes. PMID:28489864

Ecological literacy and beyond: Problem-based learning for future professionals.

PubMed

Lewinsohn, Thomas M; Attayde, José Luiz; Fonseca, Carlos Roberto; Ganade, Gislene; Jorge, Leonardo Ré; Kollmann, Johannes; Overbeck, Gerhard E; Prado, Paulo Inácio; Pillar, Valério D; Popp, Daniela; da Rocha, Pedro L B; Silva, Wesley Rodrigues; Spiekermann, Annette; Weisser, Wolfgang W

2015-03-01

Ecological science contributes to solving a broad range of environmental problems. However, lack of ecological literacy in practice often limits application of this knowledge. In this paper, we highlight a critical but often overlooked demand on ecological literacy: to enable professionals of various careers to apply scientific knowledge when faced with environmental problems. Current university courses on ecology often fail to persuade students that ecological science provides important tools for environmental problem solving. We propose problem-based learning to improve the understanding of ecological science and its usefulness for real-world environmental issues that professionals in careers as diverse as engineering, public health, architecture, social sciences, or management will address. Courses should set clear learning objectives for cognitive skills they expect students to acquire. Thus, professionals in different fields will be enabled to improve environmental decision-making processes and to participate effectively in multidisciplinary work groups charged with tackling environmental issues.

Ecology and thermal inactivation of microbes in and on interplanetary space vehicle components

NASA Technical Reports Server (NTRS)

Campbell, J. E.

1973-01-01

The thermal inactivation curve for Bacillus subtilis var. niger spores on the Viking lander is examined. Tests were conducted at 113 C and 25% RH, and over a wide range of temperatures using .001% RH and additions of P2O5 to dry the environment. Results show the 25% RH environment did not significantly reduce the survival curve, while the survival curves for spores treated under the drier .001% RH environment was reduced by a factor of 3.

Molecular biomarkers for chronological age in animal ecology.

PubMed

Jarman, Simon N; Polanowski, Andrea M; Faux, Cassandra E; Robbins, Jooke; De Paoli-Iseppi, Ricardo; Bravington, Mark; Deagle, Bruce E

2015-10-01

The chronological age of an individual animal predicts many of its biological characteristics, and these in turn influence population-level ecological processes. Animal age information can therefore be valuable in ecological research, but many species have no external features that allow age to be reliably determined. Molecular age biomarkers provide a potential solution to this problem. Research in this area of molecular ecology has so far focused on a limited range of age biomarkers. The most commonly tested molecular age biomarker is change in average telomere length, which predicts age well in a small number of species and tissues, but performs poorly in many other situations. Epigenetic regulation of gene expression has recently been shown to cause age-related modifications to DNA and to cause changes in abundance of several RNA types throughout animal lifespans. Age biomarkers based on these epigenetic changes, and other new DNA-based assays, have already been applied to model organisms, humans and a limited number of wild animals. There is clear potential to apply these marker types more widely in ecological studies. For many species, these new approaches will produce age estimates where this was previously impractical. They will also enable age information to be gathered in cross-sectional studies and expand the range of demographic characteristics that can be quantified with molecular methods. We describe the range of molecular age biomarkers that have been investigated to date and suggest approaches for developing the newer marker types as age assays in nonmodel animal species. © 2015 John Wiley & Sons Ltd.

ASSESSING THE ECOLOGICAL CONDITION OF SOUTHEAST U. S. ESTUARIES

EPA Science Inventory

As a means to assess ecological condition, 151 stations located in southeastern estuaries from Cape Henry, Virginia to Biscayne Bay, Florida were sampled by state agencies during the summer of 2000 using a probabilistic design. The design used 8 size classes of estuaries ranging ...

ECOLOGICALLY-RELEVANT QUANTIFICATION OF STREAMFLOW REGIMES IN WESTERN STREAMS

EPA Science Inventory

This report describes the rationale for and application of a protocol for estimation of ecologically-relevant streamflow metrics that quantify streamflow regime for ungaged sites subject to a range of human impact. The analysis presented here is focused on sites sampled by the U....

A classification of ecological boundaries

USGS Publications Warehouse

Strayer, D.L.; Power, M.E.; Fagan, W.F.; Pickett, S.T.A.; Belnap, J.

2003-01-01

Ecologists use the term boundary to refer to a wide range of real and conceptual structures. Because imprecise terminology may impede the search for general patterns and theories about ecological boundaries, we present a classification of the attributes of ecological boundaries to aid in communication and theory development. Ecological boundaries may differ in their origin and maintenance, their spatial structure, their function, and their temporal dynamics. A classification system based on these attributes should help ecologists determine whether boundaries are truly comparable. This system can be applied when comparing empirical studies, comparing theories, and testing theoretical predictions against empirical results.

Development of microsatellite markers using next-generation sequencing for the columnar cactus Echinopsis chiloensis (Cactaceae).

PubMed

Ossa, Carmen G; Larridon, Isabel; Peralta, Gioconda; Asselman, Pieter; Pérez, Fernanda

2016-12-01

The aim of this study was to develop microsatellite markers as a tool to study population structure, genetic diversity and effective population size of Echinopsis chiloensis, an endemic cactus from arid and semiarid regions of Central Chile. We developed 12 polymorphic microsatellite markers for E. chiloensis using next-generation sequencing and tested them in 60 individuals from six sites, covering all the latitudinal range of this species. The number of alleles per locus ranged from 3 to 8, while the observed (Ho) and expected (He) heterozygosity ranged from 0.0 to 0.80 and from 0.10 to 0.76, respectively. We also detected significant differences between sites, with F ST values ranging from 0.05 to 0.29. Microsatellite markers will enable us to estimate genetic diversity and population structure of E. chiloensis in future ecological and phylogeographic studies.

Enhanced resistance of the Pamirs high-mountain strain of Cryptococcus albidus to UV radiation of an ecological range

DOE Office of Scientific and Technical Information (OSTI.GOV)

Strakhovskaya, M.G.; Lavrukhina, O.G.; Fraikin, G.Y.

The results of a comparative analysis of the resistance of Pamirs high-mountain and lowland strains of the yeast Cryptococcus albidus to UV radiation of an ecological range are presented. A high-mountain strain, adapted to elevated UV radiation in its habitat, was found to be more resistant to UV light of a total ecorange (290-400 nm), including medium-wave (290-320 nm) and long-wave (320-400 nm) UV ranges. The enhanced UV light resistance of the high-mountain strain can be explained by efficient functioning of the excision DNA repair system. 7 refs., 3 tabs.

School bullying: its nature and ecology.

PubMed

Espelage, Dorothy L; De La Rue, Lisa

2011-11-04

Recent youth suicides only highlight a persistent problem in schools - bullying and sustained peer victimization. Being a target or victim of bullying has long been recognized has having short- and long-term psychological effects on children and adolescents across the world today. School bullying is one of the most significant public health concerns facing children and adolescents. Involvement in the social phenomena of school bullying is often explained as emerging from a wide range of risk and protective factors within the social-ecology of youth. The social-ecological model posits that bullying behaviors are shaped by various interrelated contexts including individual characteristics, family, peers and the school environment. Research is reviewed to highlight the correlates of bullying involvement across these context using social-ecological and social-learning frameworks. Meta-analytic studies are reviewed on the short- and long-term impact of bullying involvement and efficacy of bullying prevention programs. Specific recommendations for prevention planning and future research efforts are provided. Bullying is a multi-faceted issue, which is best understood in the larger social context in which it occurs. Individual characteristics of students contribute to bullying involvement when students have families that promote violence, teachers that ignore or dismiss bullying, schools that have negative climates and students who socialize with friends who bully. These social contexts need to be targeted in bully prevention programs to reduce bullying and peer victimization in schools.

The diversity, ecology and evolution of extrafloral nectaries: current perspectives and future challenges

PubMed Central

Marazzi, Brigitte; Bronstein, Judith L.; Koptur, Suzanne

2013-01-01

Background Plants in over one hundred families in habitats worldwide bear extrafloral nectaries (EFNs). EFNs display a remarkable diversity of evolutionary origins, as well as diverse morphology and location on the plant. They secrete extrafloral nectar, a carbohydrate-rich food that attracts ants and other arthropods, many of which protect the plant in return. By fostering ecologically important protective mutualisms, EFNs play a significant role in structuring both plant and animal communities. And yet researchers are only now beginning to appreciate their importance and the range of ecological, evolutionary and morphological diversity that EFNs exhibit. Scope This Highlight features a series of papers that illustrate some of the newest directions in the study of EFNs. Here, we introduce this set of papers by providing an overview of current understanding and new insights on EFN diversity, ecology and evolution. We highlight major gaps in our current knowledge, and outline future research directions. Conclusions Our understanding of the roles EFNs play in plant biology is being revolutionized with the use of new tools from developmental biology and genomics, new modes of analysis allowing hypothesis-testing in large-scale phylogenetic frameworks, and new levels of inquiry extending to community-scale interaction networks. But many central questions remain unanswered; indeed, many have not yet been asked. Thus, the EFN puzzle remains an intriguing challenge for the future. PMID:23704115

Bacterial genospecies that are not ecologically coherent: population genomics of Rhizobium leguminosarum

PubMed Central

Kumar, Nitin; Lad, Ganesh; Giuntini, Elisa; Kaye, Maria E.; Udomwong, Piyachat; Shamsani, N. Jannah; Young, J. Peter W.; Bailly, Xavier

2015-01-01

Biological species may remain distinct because of genetic isolation or ecological adaptation, but these two aspects do not always coincide. To establish the nature of the species boundary within a local bacterial population, we characterized a sympatric population of the bacterium Rhizobium leguminosarum by genomic sequencing of 72 isolates. Although all strains have 16S rRNA typical of R. leguminosarum, they fall into five genospecies by the criterion of average nucleotide identity (ANI). Many genes, on plasmids as well as the chromosome, support this division: recombination of core genes has been largely within genospecies. Nevertheless, variation in ecological properties, including symbiotic host range and carbon-source utilization, cuts across these genospecies, so that none of these phenotypes is diagnostic of genospecies. This phenotypic variation is conferred by mobile genes. The genospecies meet the Mayr criteria for biological species in respect of their core genes, but do not correspond to coherent ecological groups, so periodic selection may not be effective in purging variation within them. The population structure is incompatible with traditional ‘polyphasic taxonomy′ that requires bacterial species to have both phylogenetic coherence and distinctive phenotypes. More generally, genomics has revealed that many bacterial species share adaptive modules by horizontal gene transfer, and we envisage a more consistent taxonomic framework that explicitly recognizes this. Significant phenotypes should be recognized as ‘biovars' within species that are defined by core gene phylogeny. PMID:25589577

Occurrence, composition and ecological restoration of organic pollutants in water environment of South Canal, China

NASA Astrophysics Data System (ADS)

Wang, Y. Z.; Lin, C.; Zhou, X. S.; Zhang, Y.; Han, C. G.

2017-08-01

Ecological restoration of polluted river water was carried out in South Canal by adding microbial water purifying agents and biological compound enzymes. The objective of present study was to investigate the ecological restoration effect of organic pollutants by this efficient immobilized microbial technologies, analysis the occurrence and composition of organic pollutants including fifteen persistent organochlorine pesticides (OCPs), seventeen polycyclic aromatic hydrocarbons (PAHs) and eighteen organophosphorus pesticides (OPPs) both in natural water environment and ecological restoration area of South Canal, China. Results showed that the total concentrations of OCPs ranged from 1.11 to 1.78 ng·L-1, PAHs from 52.76 to 60.28 ng·L-1, and OPPs from 6.51 to 17.50 ng·L-1. Microbial water purifying agents and biological compound enzymes essentially had no effects on biological degradation of OCPs and PAHs in the river, but could remove OPPs with degradation rates ranging from 19.6% to 62.8% (35.2% in average). Degradation mechanisms of microbial water purifying agents and biological compound enzymes on OCPs, PAHs and OPPs remained to be further studied. This technology has a certain value in practical ecological restoration of organic pollutants in rivers and lakes.

Hydrologic, ecologic, and geomorphic responses of Brewery Creek to construction of a residential subdivision, Dane County, Wisconsin, 1999-2002

USGS Publications Warehouse

Selbig, William R.; Jopke, Peter L.; Marhshall, David W.; Sorge, Michael J.

2004-01-01

Other physical, biological, and ecological surveys including macroinvertebrates, fish, habitat, and geomorphology were done on segments of Brewery Creek affected by the study area. Macroinvertebrate sampling results (Hilsenhoff Biotic Index value, or HBI), on Brewery Creek ranged from 'very good' to 'good' water-quality with no appreciable differences during any phase of construction activity. Results for fish-community composition, however, were within the 'poor' range (Index of Biotic Integrity value, or IBI) during each year of testing. A general absence of intolerant species, with the exception of brown trout, reflects the low IBI values. Habitat values did not change significantly from preconstruction to postconstruction phases. Although installation of a double-celled culvert in Brewery Creek most likely altered the width-to-depth ratio in that reach, the overall habitat rating remained 'fair'. Fluvial geomorphology classifications including channel cross sections, bed- and bank-erosion surveys, and pebble counts did not indicate that stream geomorphic characteristics were altered by home-construction activity in the study area. Increases in fine-grained sediment at various cross sections were attributed to instream erosion processes, such as bank slumping, rather than increases in sediment delivery from the nearby construction site.

Dinosaur energetics: setting the bounds on feasible physiologies and ecologies.

PubMed

Clarke, Andrew

2013-09-01

The metabolic status of dinosaurs has long been debated but remains unresolved as no consistent picture has emerged from a range of anatomical and isotopic evidence. Quantitative analysis of dinosaur energetics, based on general principles applicable to all vertebrates, shows that many features of dinosaur lifestyle are compatible with a physiology similar to that of extant lizards, scaled up to dinosaur body masses and temperatures. The analysis suggests that sufficient metabolic scope would have been available to support observed dinosaur growth rates and allow considerable locomotor activity, perhaps even migration. Since at least one dinosaur lineage evolved true endothermy, this study emphasizes there was no single dinosaur physiology. Many small theropods were insulated with feathers and appear to have been partial or full endotherms. Uninsulated small taxa, and all juveniles, presumably would have been ectothermic, with consequent diurnal and seasonal variations in body temperature. In larger taxa, inertial homeothermy would have resulted in warm and stable body temperatures but with a basal metabolism significantly below that of extant mammals or birds of the same size. It would appear that dinosaurs exhibited a range of metabolic levels to match the broad spectrum of ecological niches they occupied.

An ecological study on suicide and homicide in Brazil.

PubMed

Bando, Daniel Hideki; Lester, David

2014-04-01

The objective was to evaluate correlations between suicide, homicide and socio-demographic variables by an ecological study. Mortality and socio-demographic data were collected from official records of the Ministry of Health and IBGE (2010), aggregated by state (27). The data were analyzed using correlation techniques, factor analysis, principal component analysis with a varimax rotation and multiple linear regression. Suicide age-adjusted rates for the total population, men and women were 5.0, 8.0, and 2.2 per 100,000 inhabitants respectively. The suicide rates ranged from 2.7 in Pará to 9.1 in Rio Grande do Sul. Homicide for the total population, men and women were 27.2, 50.8, and 4.5 per 100,000, respectively. The homicide rates ranged from 13.0 in Santa Catarina to 68.9 in Alagoas. Suicide and homicide were negatively associated, the significance persisted among men. Unemployment was negatively correlated with suicide and positively with homicide. Different socio-demographic variables were found to correlate with suicide and homicide in the regressions. Suicide showed a pattern suggesting that, in Brazil, it is related to high socioeconomic status. Homicide seemed to follow the pattern found in other countries, associated with lower social and economic status.

Genetic diversity in Capsicum baccatum is significantly influenced by its ecogeographical distribution.

PubMed

Albrecht, Elena; Zhang, Dapeng; Mays, Anne Deslattes; Saftner, Robert A; Stommel, John R

2012-08-06

The exotic pepper species Capsicum baccatum, also known as the aji or Peruvian hot pepper, is comprised of wild and domesticated botanical forms. The species is a valuable source of new genes useful for improving fruit quality and disease resistance in C. annuum sweet bell and hot chile pepper. However, relatively little research has been conducted to characterize the species, thus limiting its utilization. The structure of genetic diversity in a plant germplasm collection is significantly influenced by its ecogeographical distribution. Together with DNA fingerprints derived from AFLP markers, we evaluated variation in fruit and plant morphology of plants collected across the species native range in South America and evaluated these characters in combination with the unique geography, climate and ecology at different sites where plants originated. The present study mapped the ecogeographic distribution, analyzed the spatial genetic structure, and assessed the relationship between the spatial genetic pattern and the variation of morphological traits in a diverse C. baccatum germplasm collection spanning the species distribution. A combined diversity analysis was carried out on the USDA-ARS C. baccatum germplasm collection using data from GIS, morphological traits and AFLP markers. The results demonstrate that the C. baccatum collection covers wide geographic areas and is adapted to divergent ecological conditions in South America ranging from cool Andean highland to Amazonia rainforest. A high level of morphological diversity was evident in the collection, with fruit weight the leading variable. The fruit weight distribution pattern was compatible to AFLP-based clustering analysis for the collection. A significant spatial structure was observed in the C. baccatum gene pool. Division of the domesticated germplasm into two major regional groups (Western and Eastern) was further supported by the pattern of spatial population structure. The results reported improve our understanding of the combined effects of geography, ecology and human intervention on organization of the C. baccatum genepool. The results will facilitate utilization of C. baccatum for crop improvement and species conservation by providing a framework for efficient germplasm collection management and guidance for future plant acquisitions.

Genetic diversity in Capsicum baccatum is significantly influenced by its ecogeographical distribution

PubMed Central

2012-01-01

Background The exotic pepper species Capsicum baccatum, also known as the aji or Peruvian hot pepper, is comprised of wild and domesticated botanical forms. The species is a valuable source of new genes useful for improving fruit quality and disease resistance in C. annuum sweet bell and hot chile pepper. However, relatively little research has been conducted to characterize the species, thus limiting its utilization. The structure of genetic diversity in a plant germplasm collection is significantly influenced by its ecogeographical distribution. Together with DNA fingerprints derived from AFLP markers, we evaluated variation in fruit and plant morphology of plants collected across the species native range in South America and evaluated these characters in combination with the unique geography, climate and ecology at different sites where plants originated. Results The present study mapped the ecogeographic distribution, analyzed the spatial genetic structure, and assessed the relationship between the spatial genetic pattern and the variation of morphological traits in a diverse C. baccatum germplasm collection spanning the species distribution. A combined diversity analysis was carried out on the USDA-ARS C. baccatum germplasm collection using data from GIS, morphological traits and AFLP markers. The results demonstrate that the C. baccatum collection covers wide geographic areas and is adapted to divergent ecological conditions in South America ranging from cool Andean highland to Amazonia rainforest. A high level of morphological diversity was evident in the collection, with fruit weight the leading variable. The fruit weight distribution pattern was compatible to AFLP-based clustering analysis for the collection. A significant spatial structure was observed in the C. baccatum gene pool. Division of the domesticated germplasm into two major regional groups (Western and Eastern) was further supported by the pattern of spatial population structure. Conclusions The results reported improve our understanding of the combined effects of geography, ecology and human intervention on organization of the C. baccatum genepool. The results will facilitate utilization of C. baccatum for crop improvement and species conservation by providing a framework for efficient germplasm collection management and guidance for future plant acquisitions. PMID:22866868

Pollution, ecological-health risks, and sources of heavy metals in soil of the northeastern Qinghai-Tibet Plateau.

PubMed

Wu, Jun; Lu, Jian; Li, Leiming; Min, Xiuyun; Luo, Yongming

2018-06-01

The Qinghai-Tibet Plateau, especially the northeastern region, is not a pure land any more due to recently increasing anthropogenic activities. This study collected soil samples from 70 sites of the northeastern Qinghai-Tibet Plateau to evaluate pollution, ecological-health risks, and possible pollution sources of heavy metals. The concentrations of heavy metals in soil were relatively high. Values of geo-accumulation index exhibited that Hg pollution was the most serious meanwhile Hg possessed the strongest enrichment feature based on enrichment factor values. The modified degrees of contamination showed that about 54.3% and 17.1% of sampling sites were at moderate and high contamination degree while pollution load indexes illustrated that 72.9% and 27.1% of sampling sites possessed moderate and high contamination level, respectively. Ecological risk indexes of heavy metals in soil ranged from 234.6 to 3759.0, suggesting that most of sites were under considerable/very high risks. Cancer risks for adults and children were determined as high and high-very high levels while non-cancer risks for children were high although those for adults were low. Industrial source contributed to the main fraction of ecological and health risks. Summarily speaking, heavy metals in soil of the study area has caused significantly serious pollution and exerted high potential ecological and health risks, especially for children who are more susceptible to hurt from pollutants. Therefore, more efficient and strict pollution control and management in study area should be put out as soon as possible. Copyright © 2018 Elsevier Ltd. All rights reserved.

Maintaining resilience in the face of climate change: Chapter 8

USGS Publications Warehouse

Camacho, Alejandro E.; Beard, T. Douglas

2014-01-01

Climate change, when combined with more conventional stress from human exploitation, calls into question the capacity of both existing ecological communities and resource management institutions to experience disturbances while substantially retaining their same functions and identities (Zellmer and Gunderson 2009; Ruhl 2011). In other words, the physical and biological effects of climate change raise fundamental challenges to the resilience of natural ecosystems (Gunderson and Holling 2002). Perhaps more importantly, the projected scope of ecological shifts from global climate change-and uncertainty about such changes-significantly stresses the capacity of legal institutions to manage ecosystem change (Camacho 2009). Existing governmental institutions lack the adaptive capacity to manage such substantial changes to ecological and legal systems. In particular, regulators and managers lack information about ecological effects and alternative management strategies for managing the effects of climate change (Karkkainen 2008; Camacho 2009), as well as the institutional infrastructure for obtaining such information (Peters 2008).A number of recent initiatives have been proposed to address the effects of climate change on ecological systems. However, these nascent programs do not fully meet the needs for developing adaptive capacity. A federal, publicly accessible, and system-wide portal and clearinghouse will help regulators at all levels of government manage the effects and uncertainty from climate change (DiMento and Ingram 2005; Farber 2007). Such an information infrastructure, combined with a range of incentives that encourage regulators to engage in adaptive management and programmatic adjustment over time (Baron et al. 2009), will help governmental and private institutions become more resilient and capable of managing the physical and human institutional effects of changing climate (Camacho 2009).

Spatial ecology of coastal Atlantic cod Gadus morhua associated with parasite load.

PubMed

Aalvik, I M; Moland, E; Olsen, E M; Stenseth, N C

2015-08-01

Acoustic tags and receivers were used to investigate the spatial ecology of coastal Atlantic cod Gadus morhua (n = 32, mean fork length: 50 cm, range: 33-80 cm) on the Norwegian Skagerrak coast in 2012. Monthly home ranges (HR), swimming activity and depth use varied considerably among individuals and through the months of June, July and August. HR sizes for the period ranged from 0.25 to 5.20 km2 (mean = 2.30 km2. Two thirds of the tagged G. morhua were infected with black spot disease Cryptocotyle lingua parasites; these fish had larger HRs and occupied deeper water compared with non-infected fish. The infected fish also tended to be more active in terms of horizontal swimming. From an ecological and evolutionary perspective, any environmental change that modifies G. morhua behaviour may therefore also alter the parasite load of the population, and its conservation and fishery status. © 2015 The Fisheries Society of the British Isles.

Three-dimensional habitat structure and landscape genetics: a step forward in estimating functional connectivity.

PubMed

Milanesi, P; Holderegger, R; Bollmann, K; Gugerli, F; Zellweger, F

2017-02-01

Estimating connectivity among fragmented habitat patches is crucial for evaluating the functionality of ecological networks. However, current estimates of landscape resistance to animal movement and dispersal lack landscape-level data on local habitat structure. Here, we used a landscape genetics approach to show that high-fidelity habitat structure maps derived from Light Detection and Ranging (LiDAR) data critically improve functional connectivity estimates compared to conventional land cover data. We related pairwise genetic distances of 128 Capercaillie (Tetrao urogallus) genotypes to least-cost path distances at multiple scales derived from land cover data. Resulting β values of linear mixed effects models ranged from 0.372 to 0.495, while those derived from LiDAR ranged from 0.558 to 0.758. The identification and conservation of functional ecological networks suffering from habitat fragmentation and homogenization will thus benefit from the growing availability of detailed and contiguous data on three-dimensional habitat structure and associated habitat quality. © 2016 by the Ecological Society of America.

New Ediacara fossils preserved in marine limestone and their ecological implications

PubMed Central

Chen, Zhe; Zhou, Chuanming; Xiao, Shuhai; Wang, Wei; Guan, Chengguo; Hua, Hong; Yuan, Xunlai

2014-01-01

Ediacara fossils are central to our understanding of animal evolution on the eve of the Cambrian explosion, because some of them likely represent stem-group marine animals. However, some of the iconic Ediacara fossils have also been interpreted as terrestrial lichens or microbial colonies. Our ability to test these hypotheses is limited by a taphonomic bias that most Ediacara fossils are preserved in sandstones and siltstones. Here we report several iconic Ediacara fossils and an annulated tubular fossil (reconstructed as an erect epibenthic organism with uniserial arranged modular units), from marine limestone of the 551–541 Ma Dengying Formation in South China. These fossils significantly expand the ecological ranges of several key Ediacara taxa and support that they are marine organisms rather than terrestrial lichens or microbial colonies. Their close association with abundant bilaterian burrows also indicates that they could tolerate and may have survived moderate levels of bioturbation. PMID:24566959

New Ediacara fossils preserved in marine limestone and their ecological implications.

PubMed

Chen, Zhe; Zhou, Chuanming; Xiao, Shuhai; Wang, Wei; Guan, Chengguo; Hua, Hong; Yuan, Xunlai

2014-02-25

Ediacara fossils are central to our understanding of animal evolution on the eve of the Cambrian explosion, because some of them likely represent stem-group marine animals. However, some of the iconic Ediacara fossils have also been interpreted as terrestrial lichens or microbial colonies. Our ability to test these hypotheses is limited by a taphonomic bias that most Ediacara fossils are preserved in sandstones and siltstones. Here we report several iconic Ediacara fossils and an annulated tubular fossil (reconstructed as an erect epibenthic organism with uniserial arranged modular units), from marine limestone of the 551-541 Ma Dengying Formation in South China. These fossils significantly expand the ecological ranges of several key Ediacara taxa and support that they are marine organisms rather than terrestrial lichens or microbial colonies. Their close association with abundant bilaterian burrows also indicates that they could tolerate and may have survived moderate levels of bioturbation.

Movement and feeding ecology of recently emerged steelhead in Lake Ontario tributaries

USGS Publications Warehouse

Johnson, James H.; McKenna, James E.; Douglass, Kevin A.

2012-01-01

Steelhead (Oncorhynchus mykiss) ascend several Lake Ontario tributaries to spawn and juveniles are often the most abundant salmonid where spawning is successful. Movement and diet of recently emerged subyearling steelhead were examined in three New York tributaries of Lake Ontario. Downstream movement occurred mainly at night and consisted of significantly smaller fry that were feeding at lower levels than resident fry. Fry fed at the highest rate during the day and chironomids and baetids were the main components of their diet. The diet composition of steelhead fry was closely associated with the composition of the benthos in Trout Brook but more similar to the composition of the drift in the other streams. Daily ration was similar among streams, ranging from 10.2 to 14.3%. These findings are consistent with previous findings on the ecology of steelhead fry, as well as fry of other salmonid species

Allometry and stoichiometry of unicellular, colonial and multicellular phytoplankton.

PubMed

Beardall, John; Allen, Drew; Bragg, Jason; Finkel, Zoe V; Flynn, Kevin J; Quigg, Antonietta; Rees, T Alwyn V; Richardson, Anthony; Raven, John A

2009-01-01

Phytoplankton life forms, including unicells, colonies, pseudocolonies, and multicellular organisms, span a huge size range. The smallest unicells are less than 1 microm3 (e.g. cyanobacteria), while large unicellular diatoms may attain 10(9) microm3, being visible to the naked eye. Phytoplankton includes chemo-organotrophic unicells, colonies and multicellular organisms that depend on symbionts or kleptoplastids for their capacity to photosynthesize. Analyses of physical (transport within cells, diffusion boundary layers, package effect, turgor, and vertical movements) and biotic (grazing, viruses and other parasitoids) factors indicate potential ecological constraints and opportunities that differ among the life forms. There are also variations among life forms in elemental stoichiometry and in allometric relations between biovolume and specific growth. While many of these factors probably have ecological and evolutionary significance, work is needed to establish those that are most important, warranting explicit description in models. Other factors setting limitations on growth rate (selecting slow-growing species) await elucidation.

Ecology of red maple swamps in the glaciated northeast: A community profile

DOE Office of Scientific and Technical Information (OSTI.GOV)

Golet, F.C.; Calhoun, A.J.K.; DeRagon, W.R.

1993-06-01

In many areas of the glaciated northeastern United States, forested wetlands dominated by red maple (Acer rubrum) cover more of the landscape than all other nontidal wetland types combined. Yet surprisingly little of their ecology, functions, or social significance has been documented. Bogs, salt marshes, Atlantic white cedar swamps, and other less common types of wetlands have received considerable attention from scientists, but, except for botanical surveys, red maple swamps have been largely ignored. The report conveys what is known about these common wetlands and identifies topics most in need of investigation. Red maple swamps are so abundant and somore » widely distributed in the Northeast that their physical, chemical, and biological properties range widely as well, and their values to society are diverse. The central focus of the U.S. Fish and Wildlife Service community profile series is the plant and animal communities of wetlands and deepwater habitats.« less

An ecological study for Sri Lanka about health effects of coconut.

PubMed

Athauda, L K; Wickremasinghe, A R; Kumarendran, B; Kasturiratne, A

2015-09-01

An ecological correlation study was conducted to determine the association between consumption of coconut products and cardiovascular disease (CVD) deaths in Sri Lanka. Data on coconut consumption patterns from 1961 to 2006 were abstracted from the FAO database, and mortality data from reports of the Department of Census and Statistics, and UN databases. Correlational and regression analyses were carried out. There was no increase in the per capita consumption of coconut products from 1961 to 2006 (range 54.1-76.2kg/ capita/year). The CVD death rates and the proportionate mortality rate due to CVD increased from 1961 to 2006. CVD death rates were significantly associated with per capita GDP, percentage of urban population, and elderly dependency ratio but not consumption of coconut products after adjusting for the other variables (R2=0.94). The results do not provide evidence at the population level that consumption of coconut products increases mortality due to cardiovascular diseases.

Status and ecological effects of the world's largest carnivores.

PubMed

Ripple, William J; Estes, James A; Beschta, Robert L; Wilmers, Christopher C; Ritchie, Euan G; Hebblewhite, Mark; Berger, Joel; Elmhagen, Bodil; Letnic, Mike; Nelson, Michael P; Schmitz, Oswald J; Smith, Douglas W; Wallach, Arian D; Wirsing, Aaron J

2014-01-10

Large carnivores face serious threats and are experiencing massive declines in their populations and geographic ranges around the world. We highlight how these threats have affected the conservation status and ecological functioning of the 31 largest mammalian carnivores on Earth. Consistent with theory, empirical studies increasingly show that large carnivores have substantial effects on the structure and function of diverse ecosystems. Significant cascading trophic interactions, mediated by their prey or sympatric mesopredators, arise when some of these carnivores are extirpated from or repatriated to ecosystems. Unexpected effects of trophic cascades on various taxa and processes include changes to bird, mammal, invertebrate, and herpetofauna abundance or richness; subsidies to scavengers; altered disease dynamics; carbon sequestration; modified stream morphology; and crop damage. Promoting tolerance and coexistence with large carnivores is a crucial societal challenge that will ultimately determine the fate of Earth's largest carnivores and all that depends upon them, including humans.

Basal metabolic rate in free-living tropical birds: the influence of phylogenetic, behavioral, and ecological factors

PubMed Central

Tolstenkov, Oleg; Zubkova, Ekaterina; Solovyeva, Eugenia; Kerimov, Anvar

2018-01-01

Abstract The majority of our knowledge of avian energetics is based on studies of birds from temperate and high latitudes. Using the largest existing sample of wild-caught Old World tropical species, we showed that birds from Southern Vietnam had lower basal metabolic rate (BMR) than temperate species. The strongest dissimilarity between tropical and temperate species was the low scaling exponent in the allometric relation between BMR and body mass in tropical birds (the regression slope was 0.573). The passerine migrants to temperate and high latitudes had higher BMR than tropical sedentary passerines. Body mass alone accounted for 93% of the variation in BMR (body mass ranged from 5 to 252 g). Contrary to some other studies, we did not find evidence besides the above mentioned that phylogeny, taxonomy, behavior, or ecology have a significant influence on BMR variation among tropical birds. PMID:29492036

Molecular Ecology of Hypersaline Microbial Mats: Current Insights and New Directions.

PubMed

Wong, Hon Lun; Ahmed-Cox, Aria; Burns, Brendan Paul

2016-01-05

Microbial mats are unique geobiological ecosystems that form as a result of complex communities of microorganisms interacting with each other and their physical environment. Both the microorganisms present and the network of metabolic interactions govern ecosystem function therein. These systems are often found in a range of extreme environments, and those found in elevated salinity have been particularly well studied. The purpose of this review is to briefly describe the molecular ecology of select model hypersaline mat systems (Guerrero Negro, Shark Bay, S'Avall, and Kiritimati Atoll), and any potentially modulating effects caused by salinity to community structure. In addition, we discuss several emerging issues in the field (linking function to newly discovered phyla and microbial dark matter), which illustrate the changing paradigm that is seen as technology has rapidly advanced in the study of these extreme and evolutionally significant ecosystems.

Ecology and biology of paddlefish in North America: historical perspectives, management approaches, and research priorities

USGS Publications Warehouse

Jennings, Cecil A.; Zigler, Stephen J.

2000-01-01

Paddlefish (Polyodon spathula, Polyodontidae) are large, mostly-riverine fish that once were abundant in medium- to large-sized river systems throughout much of the central United States. Concern for paddlefish populations has grown from a regional fisheries issue to one of national importance for the United States. In 1989, the U.S. Fish and Wildlife Service (USFWS) was petitioned to list paddlefish as a federally threatened species under the Endangered Species Act. The petition was not granted, primarily because of a lack of empirical data on paddlefish population size, age structure, growth, or harvest rates across the present 22-state range. Nonetheless, concern for paddlefish populations prompted the USFWS to recommend that paddlefish be protected through the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). The addition of paddlefish to Appendix II of CITES, which was approved in March 1992, provides a mechanism to curtail illegal trade in paddlefish and their parts and supports a variety of conservation plans. Paddlefish populations have been negatively affected by overharvest, river modifications, and pollution, but the paddlefish still occupies much of its historic range and most extant populations seem to be stable. Although many facets of paddlefish biology and ecology are well understood, the lack of information on larval and juvenile ecology, mechanisms that determine recruitment, population size and vital rates, interjurisdictional movements, and the effects of anthropogenic activities present significant obstacles for managing paddlefish populations. Questions about the size and structure of local populations, and how such populations are affected by navigation traffic, dams, and pollution are regarded as medium priority areas for future research. The availability of suitable spawning habitat and overall reproductive success in impounded rivers are unknown and represent critical areas for future research. Research on reproductive and recruitment success in impounded rivers have significant implications for managing paddlefish, as rivers are modified further for human use.

The link between obesity and the built environment. Evidence from an ecological analysis of obesity and vehicle miles of travel in California.

PubMed

Lopez-Zetina, Javier; Lee, Howard; Friis, Robert

2006-12-01

Obesity and physical inactivity are known to be risk factors for many chronic diseases including hypertension, coronary artery disease, diabetes, and cancer. We sought to explore the association between an indicator of transportation data (Vehicle Miles of Travel, VMT) at the county level as it relates to obesity and physical inactivity in California. Data from the California Health Interview Survey 2001 (CHIS 2001), the US 2000 Census, and the California Department of Transportation were merged to examine ecological correlations between vehicle miles of travel, population density, commute time, and county indicators of obesity and physical inactivity. Obesity was measured by body mass index (BMI). Physical inactivity was based on self-reported behaviors including walking, bicycling, and moderate to vigorous activity. The unit of analysis was the county. Thirty-three counties in California with population size greater than 100,000 persons per county were retained in the analyses. CHIS 2001 statewide obesity prevalence ranged from 11.2% to 28.5% by county. Physical inactivity ranged from 13.4% to 35.7%. Daily vehicle miles of travel ranged from 3.3 million to 183.8 million per county. By rank bivariate correlation, obesity and physical inactivity were significantly associated (p<0.01). Furthermore, by rank analysis of variance, the highest mean rank obesity was associated with the highest rank of VMT (p<0.01). Similar rank patterns were observed between obesity and physical inactivity and commute time. Associations between VMT and physical inactivity were examined but failed to reach statistical significance. This analysis adds to the growing evidence supporting the association between VMT (a measure of automobile transportation) and obesity. An urban design characterized by over dependence on motorized transportation may be related to adverse health effects.

Environmental factors affecting contaminant toxicity in aquatic and terrestrial vertebrates

USGS Publications Warehouse

Rattner, Barnett A.; Heath, Alan G.; Hoffman, David J.; Rattner, Barnett A.; Burton, G. Allen; Cairns, John

2003-01-01

Physical and natural factors have long been known to influence the toxicity of environmental contaminants to vertebrates. The majority of data that address this topic have been derived from studies on fish, highly inbred laboratory rodents, and man.' The degree to which these factors modify toxicity has principally been elucidated by controlled laboratory experiments. Until recently, the significance of such effects to free-ranging vertebrates Figure 23.1 was frequently overlooked in ecological risk assessments.' Drawing upon controlled experiments and observational science, we overview environmental factors that influence pollutant toxicity in fish and wildlife, and present some perspective on their ecotoxicological significance.

36 CFR 219.2 - Principles.

Code of Federal Regulations, 2010 CFR

2010-07-01

... increased human uses, it is essential that uses of today do not impair the functioning of ecological... achievement of goals. (b) Planning contributes to social and economic sustainability by providing for a wide... responsive to a broad range of ecological, social, and economic. (5) Planning acknowledges the limits and...

Dynamics at Intermediate Time Scales and Management of Ecological Populations

DTIC Science & Technology

2017-05-10

thinking about the importance of transients is to recognize the importance of serial autocorrelation in time of forcing terms over realistic ecological time...rich areas helps produce divergent home range responses bet - ween individuals from difference age classes. This model has broad applications for

The potential for host switching via ecological fitting in the emerald ash borer-host plant system.

PubMed

Cipollini, Don; Peterson, Donnie L

2018-02-27

The traits used by phytophagous insects to find and utilize their ancestral hosts can lead to host range expansions, generally to closely related hosts that share visual and chemical features with ancestral hosts. Host range expansions often result from ecological fitting, which is the process whereby organisms colonize and persist in novel environments, use novel resources, or form novel associations with other species because of the suites of traits that they carry at the time they encounter the novel environment. Our objective in this review is to discuss the potential and constraints on host switching via ecological fitting in emerald ash borer, Agrilus planipennis, an ecologically and economically important invasive wood boring beetle. Once thought of as an ash (Fraxinus spp.) tree specialist, recent studies have revealed a broader potential host range than was expected for this insect. We discuss the demonstrated host-use capabilities of this beetle, as well as the potential for and barriers to the adoption of additional hosts by this beetle. We place our observations in the context of biochemical mechanisms that mediate the interaction of these beetles with their host plants and discuss whether evolutionary host shifts are a possible outcome of the interaction of this insect with novel hosts.

Occurrences, sources and risk assessment of short- and medium-chain chlorinated paraffins in sediments from the middle reaches of the Yellow River, China.

PubMed

Qiao, Lin; Xia, Dan; Gao, Lirong; Huang, Huiting; Zheng, Minghui

2016-12-01

Chlorinated paraffins (CPs), one class of hydrophobic and toxic compounds, are easily adsorbed into sediments and then pose potential risks to the ecosystem and human health. However, few researches on short- and medium-chain CPs (SCCPs and MCCPs) in sediments have been performed. In order to comprehensively investigate the spatial distributions, sources, and ecological risks of CPs, sediments collected from the middle reaches of the Yellow River were analyzed by two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC × GC-TOFMS). The concentrations of SCCPs and MCCPs ranged from 11.6 to 9.76 × 10 3  ng/g dry weight (dw) and from 8.33 to 168 ng/g dw, respectively. No significant correlation was found between total organic carbon (TOC) and CP concentrations (P > 0.05). The spatial distributions showed that contamination levels of CPs were relevant to human activities. In addition, two types of sediment samples were classified by hierarchical cluster analysis (HCA) and results indicated the predominant congener groups were C 10 Cl 6-7 for SCCPs and C 14 Cl 7-8 for MCCPs. Principal component analysis (PCA) revealed that SCCPs and MCCPs in the sediments may have different sources, and SCCPs are likely to come from the production and use of CP-42 and CP-52. Moreover, complex environmental processes, including long-range transportation via the atmosphere and/or river, deposition and degradation of CPs, resulted in increased abundances of short chain and low chlorinated congeners in sediment samples compared with commercial mixtures, and different homolog patterns among samples. The significant negative correlation between SCCP concentrations and MCCP/SCCP ratios could be related to long-range transport of CPs. A preliminary risk assessment indicated that CPs at current levels posed no significant ecological risk. Copyright © 2016 Elsevier Ltd. All rights reserved.

Gall-induction in insects: evolutionary dead-end or speciation driver?

PubMed Central

2010-01-01

Background The tree of life is significantly asymmetrical - a result of differential speciation and extinction - but general causes of such asymmetry are unclear. Differences in niche partitioning are thought to be one possible general explanation. Ecological specialization might lead to increases in diversification rate or, alternatively, specialization might limit the evolutionary potential of specialist lineages and increase their extinction risk. Here we compare the diversification rates of gall-inducing and non-galling insect lineages. Compared with other insect herbivores feeding on the same host plant, gall-inducing insects feed on plant tissue that is more nutritious and less defended, and they do so in a favorable microhabitat that may also provide some protection from natural enemies. We use sister-taxon comparisons to test whether gall-inducing lineages are more host-specific than non-galling lineages, and more or less diverse than non-gallers. We evaluate the significance of diversity bipartitions under Equal Rates Markov models, and use maximum likelihood model-fitting to test for shifts in diversification rates. Results We find that, although gall-inducing insect groups are more host-specific than their non-galling relatives, there is no general significant increase in diversification rate in gallers. However, gallers are found at both extremes - two gall-inducing lineages are exceptionally diverse (Euurina sawflies on Salicaceae and Apiomorpha scale insects on Eucalytpus), and one gall-inducing lineage is exceptionally species-poor (Maskellia armored scales on Eucalyptus). Conclusions The effect of ecological specialization on diversification rates is complex in the case of gall-inducing insects, but host range may be an important factor. When a gall-inducing lineage has a host range approximate to that of its non-galling sister, the gallers are more diverse. When the non-galler clade has a much wider host range than the galler, the non-galler is also much more diverse. There are also lineage-specific effects, with gallers on the same host group exhibiting very different diversities. No single general model explains the observed pattern. PMID:20735853

Materialist value orientations as correlates of the new ecological paradigm among university students in China.

PubMed

Chang, Genying

2015-04-01

The new ecological paradigm is an ecocentric view of the relationship between humanity and nature. This study analyzed the correlates of the new ecological paradigm in China using the responses of 1,148 university students to a questionnaire. The participating students were from Lanzhou University and Liaocheng University in China and ranged in age from 16 to 26 years. This study showed that two materialist value orientations, economic precedence over the environment and trust in technology, were negatively correlated with the new ecological paradigm. The correlates of basic values with the new ecological paradigm were mediated by economic precedence over the environment. Female students were more concerned about the environment than were male students.

The basis function approach for modeling autocorrelation in ecological data.

PubMed

Hefley, Trevor J; Broms, Kristin M; Brost, Brian M; Buderman, Frances E; Kay, Shannon L; Scharf, Henry R; Tipton, John R; Williams, Perry J; Hooten, Mevin B

2017-03-01

Analyzing ecological data often requires modeling the autocorrelation created by spatial and temporal processes. Many seemingly disparate statistical methods used to account for autocorrelation can be expressed as regression models that include basis functions. Basis functions also enable ecologists to modify a wide range of existing ecological models in order to account for autocorrelation, which can improve inference and predictive accuracy. Furthermore, understanding the properties of basis functions is essential for evaluating the fit of spatial or time-series models, detecting a hidden form of collinearity, and analyzing large data sets. We present important concepts and properties related to basis functions and illustrate several tools and techniques ecologists can use when modeling autocorrelation in ecological data. © 2016 by the Ecological Society of America.

International collaboration and comparative research on ocean top predators under CLIOTOP

NASA Astrophysics Data System (ADS)

Hobday, Alistair J.; Arrizabalaga, Haritz; Evans, Karen; Scales, Kylie L.; Senina, Inna; Weng, Kevin C.

2017-06-01

Oceanic top predators have ecological, social and economic value of global significance. These wide-ranging marine species, which include sharks, tunas and billfishes, marine mammals, turtles and seabirds, are the focus of international research attention under the Climate Impacts on Oceanic Top Predators (CLIOTOP) science programme, one of the Integrated Marine Biosphere Research (IMBeR) projects. Over more than a decade, research conducted under CLIOTOP has involved scientists from more than 30 countries, with international collaboration increasing markedly over time, and comparative analyses resulting in new knowledge and understanding of oceanic top predators. This special issue presents 27 papers arising from the 3rd CLIOTOP symposium, held in San Sebastián, Spain in September 2015, spanning topics such as conservation biology, trophic ecology, fisheries science, climate change, and adaptive management. The maturation and synthesis of CLIOTOP's collaborative research is now resulting in real-world management applications and improving understanding of potential ecological and socio-economic impacts of climate change in oceanic systems. The ultimate CLIOTOP goal of preparing both climate-sensitive predator populations and the human societies dependent on them for the impending impacts of climate change is now within reach.

Exploring Differences in Dogs’ and Wolves’ Preference for Risk in a Foraging Task

PubMed Central

Marshall-Pescini, Sarah; Besserdich, Ingo; Kratz, Corinna; Range, Friederike

2016-01-01

Both human and non-humans species face decisions in their daily lives which may entail taking risks. At the individual level, a propensity for risk-taking has been shown to be positively correlated with explorative tendencies, whereas, at the species level a more variable and less stable feeding ecology has been associated with a greater preference for risky choices. In the current study we compared two closely related species; wolves and dogs, which differ significantly in their feeding ecology and their explorative tendencies. Wolves depend on hunting for survival with a success rate of between 15 and 50%, whereas free-ranging dogs (which make up 80% of the world dog population), are largely scavengers specialized on human produce (i.e., a more geographically and temporally stable resource). Here, we used a foraging paradigm, which allowed subjects to choose between a guaranteed less preferred food vs. a more preferred food, which was however, delivered only 50% of the time (a stone being delivered the rest of time). We compared identically raised adult wolves and dogs and found that in line with the differing feeding ecologies of the two species and their explorative tendencies, wolves were more risk prone than dogs. PMID:27602005

Nonlinear and Synchronous Dissolved Organic Matter Dynamics in Streams Across an Agriculture Land Use and Climate Setting

NASA Astrophysics Data System (ADS)

Xenopoulos, M. A.; Vogt, R. J.

2014-12-01

There is now increasing evidence that non-linearity is a common response in ecological systems to pressures caused by human activities. There is also increasing evidence that exogenous environmental drivers, such as climate, induce spatial and temporal synchrony in a wide range of ecological variables. Using Moran's I and Pearson's correlation, we quantified the synchrony of dissolved organic carbon concentration (DOC) and quality (DOM; e.g., specific UV absorbance, Fluorescence Index, PARAFAC), nutrients, discharge and temperature in 40 streams that span an agriculture gradient (0 to >70% cropland), over 10 years. We then used breakpoint regression, 2D-Kolmogorov-Smirnov test and significant zero crossings (SiZer) analyses to quantify the prevalence of nonlinearity and ecological thresholds (breakpoints) where applicable. There was a high degree of synchrony in DOM quality (r > 0.7) but not DOC (r < 0.4). The degree of synchrony was driven in part by the catchment's land use. With respect to the nonlinear analyses we found non-linearity in ~50% of bivariate datasets analyzed. Non-linearity was also driven in part by the catchment's land use. Breakpoints defined different DOM properties. Nonlinearity and synchronous behaviour in DOM are intimately linked to land use.

Bacterial-fungal interactions: ecology, mechanisms and challenges.

PubMed

Deveau, Aurélie; Bonito, Gregory; Uehling, Jessie; Paoletti, Mathieu; Becker, Matthias; Bindschedler, Saskia; Hacquard, Stéphane; Hervé, Vincent; Labbé, Jessy; Lastovetsky, Olga A; Mieszkin, Sophie; Millet, Larry J; Vajna, Balázs; Junier, Pilar; Bonfante, Paola; Krom, Bastiaan P; Olsson, Stefan; van Elsas, Jan Dirk; Wick, Lukas Y

2018-05-01

Fungi and bacteria are found living together in a wide variety of environments. Their interactions are significant drivers of many ecosystem functions and are important for the health of plants and animals. A large number of fungal and bacterial families engage in complex interactions that lead to critical behavioural shifts of the microorganisms ranging from mutualism to antagonism. The importance of bacterial-fungal interactions (BFI) in environmental science, medicine and biotechnology has led to the emergence of a dynamic and multidisciplinary research field that combines highly diverse approaches including molecular biology, genomics, geochemistry, chemical and microbial ecology, biophysics and ecological modelling. In this review, we discuss recent advances that underscore the roles of BFI across relevant habitats and ecosystems. A particular focus is placed on the understanding of BFI within complex microbial communities and in regard of the metaorganism concept. We also discuss recent discoveries that clarify the (molecular) mechanisms involved in bacterial-fungal relationships, and the contribution of new technologies to decipher generic principles of BFI in terms of physical associations and molecular dialogues. Finally, we discuss future directions for research in order to stimulate synergy within the BFI research area and to resolve outstanding questions.

Chemical speciation and risk assessment of cadmium in soils around a typical coal mining area of China.

PubMed

Cheng, Siwei; Liu, Guijian; Zhou, Chuncai; Sun, Ruoyu

2018-05-21

The distribution characteristics of Cadmium (Cd) fractions in soils around a coal mining area of Huaibei coalfield were investigated, with the aim to assess its ecological risk. The total Cd concentrations in soils ranged from 0.05 to 0.87 mg/kg. The high percentage of phyto-available Cd (58%) when redox or base-acid equilibria changed. Soil pH was found to be a crucial factor affecting soil Cd fraction, and carbonate-bound Cd can be significantly affected by both organic matter and pH of soils. The static ecological evaluation models, including potential ecological risk index (PERI), geo-accumulation index (I geo ) and risk assessment code (RAC), revealed a moderate soil Cd contamination and prensented high Cd exposure risk in studied soils. However, the dynamic evaluation of Cd risk, determined using a delayed geochemical hazard (DGH), suggested that our studied soils can be classified as median-risk with a mean probability of 24.79% for Cd DGH. These results provide a better assessment for the risk development of Cd contamination in coal mining areas. Copyright © 2018 Elsevier Inc. All rights reserved.

Comparing ecohydrological processes in alien vs. native ranges: perspectives from the endangered shrub Myricaria germanica

NASA Astrophysics Data System (ADS)

Michielon, Bruno; Campagnaro, Thomas; Porté, Annabel; Hoyle, Jo; Picco, Lorenzo; Sitzia, Tommaso

2017-04-01

Comparing the ecology of woody species in their alien and native ranges may provide interesting insights for theoretical ecology, invasion biology, restoration ecology and forestry. The literature which describes the biological evolution of successful plant invaders is rich and increasing. However, no general theories have been developed about the geomorphic settings which may limit or favour the alien woody species expansion along rivers. The aim of this contribution is to explore the research opportunities in the comparison of ecohydrological processes occurring in the alien vs. the native ranges of invasive tree and shrub species along the riverine corridor. We use the endangered shrub Myricaria germanica as an example. Myricaria germanica is an Euro-Asiatic pioneer species that, in the native range, develops along natural rivers, wide and dynamic. These conditions are increasingly limited by anthropogenic constraints in most European rivers. This species has been recently introduced in New Zealand, where it is spreading in some natural rivers of the Canterbury region (South Island). We present the current knowledge about the natural and anthropogenic factors influencing this species in its native range. We compare this information with the current knowledge about the same factors influencing M. germanica invasiveness and invasibility of riparian habitats in New Zealand. We stress the need to identify potential factors which could drive life-traits and growing strategies divergence which may hinder the application to the alien ranges of existing ecohydrological knowledge from native ranges. Moreover, the pattern of expansion of the alien range of species endangered in their native ranges opens new windows for research.

High proportion of smaller ranged hummingbird species coincides with ecological specialization across the Americas.

PubMed

Sonne, Jesper; Martín González, Ana M; Maruyama, Pietro K; Sandel, Brody; Vizentin-Bugoni, Jeferson; Schleuning, Matthias; Abrahamczyk, Stefan; Alarcón, Ruben; Araujo, Andréa C; Araújo, Francielle P; Mendes de Azevedo, Severino; Baquero, Andrea C; Cotton, Peter A; Ingversen, Tanja Toftemark; Kohler, Glauco; Lara, Carlos; Guedes Las-Casas, Flor Maria; Machado, Adriana O; Machado, Caio Graco; Maglianesi, María Alejandra; Moura, Alan Cerqueira; Nogués-Bravo, David; Oliveira, Genilda M; Oliveira, Paulo E; Ornelas, Juan Francisco; Rodrigues, Licléia da Cruz; Rosero-Lasprilla, Liliana; Rui, Ana Maria; Sazima, Marlies; Timmermann, Allan; Varassin, Isabela Galarda; Wang, Zhiheng; Watts, Stella; Fjeldså, Jon; Svenning, Jens-Christian; Rahbek, Carsten; Dalsgaard, Bo

2016-02-10

Ecological communities that experience stable climate conditions have been speculated to preserve more specialized interspecific associations and have higher proportions of smaller ranged species (SRS). Thus, areas with disproportionally large numbers of SRS are expected to coincide geographically with a high degree of community-level ecological specialization, but this suggestion remains poorly supported with empirical evidence. Here, we analysed data for hummingbird resource specialization, range size, contemporary climate, and Late Quaternary climate stability for 46 hummingbird-plant mutualistic networks distributed across the Americas, representing 130 hummingbird species (ca 40% of all hummingbird species). We demonstrate a positive relationship between the proportion of SRS of hummingbirds and community-level specialization, i.e. the division of the floral niche among coexisting hummingbird species. This relationship remained strong even when accounting for climate, furthermore, the effect of SRS on specialization was far stronger than the effect of specialization on SRS, suggesting that climate largely influences specialization through species' range-size dynamics. Irrespective of the exact mechanism involved, our results indicate that communities consisting of higher proportions of SRS may be vulnerable to disturbance not only because of their small geographical ranges, but also because of their high degree of specialization. © 2016 The Author(s).

Spatial and seasonal variation in the ecological significance of nutrient recycling by larval salamanders in Appalachian headwater streams

Treesearch

S. Conor Keitzer; Reuben R. Goforth

2013-01-01

Salamanders are abundant consumers in many temperate streams and may be important recyclers of biologically essential nutrients, but their ecological role is poorly understood. The ecological significance of nutrient recycling by salamanders may vary spatially and seasonally because of their potentially patchy distribution in streams and the dynamic nature of stream...

Theoretical Issues of Validity in the Measurement of Aided Speech Reception Threshold in Noise for Comparing Nonlinear Hearing Aid Systems.

PubMed

Naylor, Graham

2016-07-01

Adaptive Speech Reception Threshold in noise (SRTn) measurements are often used to make comparisons between alternative hearing aid (HA) systems. Such measurements usually do not constrain the signal-to-noise ratio (SNR) at which testing takes place. Meanwhile, HA systems increasingly include nonlinear features that operate differently in different SNRs, and listeners differ in their inherent SNR requirements. To show that SRTn measurements, as commonly used in comparisons of alternative HA systems, suffer from threats to their validity, to illustrate these threats with examples of potentially invalid conclusions in the research literature, and to propose ways to tackle these threats. An examination of the nature of SRTn measurements in the context of test theory, modern nonlinear HAs, and listener diversity. Examples from the audiological research literature were used to estimate typical interparticipant variation in SRTn and to illustrate cases where validity may have been compromised. There can be no doubt that SRTn measurements, when used to compare nonlinear HA systems, in principle, suffer from threats to their internal and external/ecological validity. Interactions between HA nonlinearities and SNR, and interparticipant differences in inherent SNR requirements, can act to generate misleading results. In addition, SRTn may lie at an SNR outside the range for which the HA system is designed or expected to operate in. Although the extent of invalid conclusions in the literature is difficult to evaluate, examples of studies were nevertheless identified where the risk of each form of invalidity is significant. Reliable data on ecological SNRs is becoming available, so that ecological validity can be assessed. Methodological developments that can reduce the risk of invalid conclusions include variations on the SRTn measurement procedure itself, manipulations of stimulus or scoring conditions to place SRTn in an ecologically relevant range, and design and analysis approaches that take account of interparticipant differences. American Academy of Audiology.

Deconstructing mammal dispersals and faunal dynamics in SW Europe during the Quaternary

NASA Astrophysics Data System (ADS)

Palombo, Maria Rita

2014-07-01

This research aims to investigate the relationships between climate change and faunal dynamics in south-west Europe, disentangling the asynchronous and diachronous dispersal bioevents of large mammals across geographical and ecological boundaries, analysing biodiversity and its changes through time. The analysis of local versus regional biological dynamics may shed new light on whether turnovers and ecological and evolutionary changes developed because of global climate changes and related phenomena, or because of intrinsic biological factors. The SW European Quaternary fossil record is particularly suitable for studying the role of climate change at local and regional levels because of the complex physiographic and climatic heterogeneity of the study area, the presence of important geographical/ecological barriers and the complex history of invasions of species of varying geographical origin and provenance. The data base consists of taxonomically revised lists of large mammal species from selected SW European local faunal assemblages ranging in age from the Early to the late Middle Pleistocene (middle Villafranchian to early Aurelian European Land Mammal Ages). The new biochronological scheme proposed here allows for the comparison of local turnovers and biodiversity trends, yielding a better understanding of the action of geographical/ecological barriers that either prevented the range of some taxa from reaching some regions or caused delays in the dispersal of a taxon in some territories. The results obtained provide evidence that major environmental perturbations, triggering dispersal events and removing keystone species, modified the structure of the pre-existing mammalian faunas, merging previously independently-evolved taxa into new palaeo-communities. The coupled action of climatic changes and internal biotic dynamics thus caused the Quaternary SW European faunal complexes to significantly restructure. Diachroneity in local turnover across the study area probably relates to differences in local dynamic patterns of competition/coevolution, although different manifestations of global climate changes in different geographic settings would have contributed to the scale of local bioevents.

Better Few than Hungry: Flexible Feeding Ecology of Collared Lemurs Eulemur collaris in Littoral Forest Fragments

PubMed Central

Donati, Giuseppe; Kesch, Kristina; Ndremifidy, Kelard; Schmidt, Stacey L.; Ramanamanjato, Jean-Baptiste; Borgognini-Tarli, Silvana M.; Ganzhorn, Joerg U.

2011-01-01

Background Frugivorous primates are known to encounter many problems to cope with habitat degradation, due to the fluctuating spatial and temporal distribution of their food resources. Since lemur communities evolved strategies to deal with periods of food scarcity, these primates are expected to be naturally adapted to fluctuating ecological conditions and to tolerate a certain degree of habitat changes. However, behavioral and ecological strategies adopted by frugivorous lemurs to survive in secondary habitats have been little investigated. Here, we compared the behavioral ecology of collared lemurs (Eulemur collaris) in a degraded fragment of littoral forest of south-east Madagascar, Mandena, with that of their conspecifics in a more intact habitat, Sainte Luce. Methodology/Principal Findings Lemur groups in Mandena and in Sainte Luce were censused in 2004/2007 and in 2000, respectively. Data were collected via instantaneous sampling on five lemur groups totaling 1,698 observation hours. The Shannon index was used to determine dietary diversity and nutritional analyses were conducted to assess food quality. All feeding trees were identified and measured, and ranging areas determined via the minimum convex polygon. In the degraded area lemurs were able to modify several aspects of their feeding strategies by decreasing group size and by increasing feeding time, ranging areas, and number of feeding trees. The above strategies were apparently able to counteract a clear reduction in both food quality and size of feeding trees. Conclusions/Significance Our findings indicate that collared lemurs in littoral forest fragments modified their behavior to cope with the pressures of fluctuating resource availability. The observed flexibility is likely to be an adaptation to Malagasy rainforests, which are known to undergo periods of fruit scarcity and low productivity. These results should be carefully considered when relocating lemurs or when selecting suitable areas for their conservation. PMID:21625557

Examining Lives in Context: Perspectives on the Ecology of Human Development.

ERIC Educational Resources Information Center

Moen, Phyllis, Ed.; And Others

Extending the work of behavioral scientist Urie Bronfenbrenner on the social and contextual factors influencing human development, this collection of essays, from scholars in a range of disciplines, shows how Bronfenbrenner's ecological theory and research have transformed the way many social and behavioral scientists approach, think about, and…

Parallel k-Means Clustering for Quantitative Ecoregion Delineation Using Large Data Sets

Treesearch

Jitendra Kumar; Richard T. Mills; Forrest M Hoffman; William W Hargrove

2011-01-01

Identification of geographic ecoregions has long been of interest to environmental scientists and ecologists for identifying regions of similar ecological and environmental conditions. Such classifications are important for predicting suitable species ranges, for stratification of ecological samples, and to help prioritize habitat preservation and remediation efforts....

Proceedings of the 12th biennial southern silvicultural research conference

Treesearch

Kristina F. Connor; [Editor

2004-01-01

Ninety-two papers and thirty-six poster summaries address a range of issues affecting southern forests. Papers are grouped in 15 sessions that include wildlife ecology; fire ecology; natural pine management; forest health; growth and yield; upland hardwoods - natural regeneration; hardwood intermediate treatments; longleaf pine; pine plantation silviculture; site...

The ecology and evolution of gall-forming insects.

Treesearch

Peter W. Price; William J. Mattson; Yuri N. Baranchikov

1994-01-01

This international proceedings focuses on the biology, ecology, and evolution of gall-forming insects and their uniquely specialized relationships with their host plants. The individual contributions range in scope from detailed descriptive to profoundly theoretical, synthetic studies. One underlying theme of the proceedings is the important contribution of knowledge...

LTAR linkages with other research networks: Capitalizing on network interconnections

USDA-ARS?s Scientific Manuscript database

The USDA ARS Research Unit based at the Jornada Experimental Range outside of Las Cruces, NM, is a member of the USDA’s Long Term Agro-ecosystem Research (LTAR) Network, the National Science Foundation’s Long Term Ecological Research (LTER) Network, the National Ecological Observation Network (NEON)...

Social/economic/cultural components

Treesearch

Patricia L. Winter; Jonathan W. Long; Susan Charnley

2014-01-01

Previous chapters of this synthesis rely on multiple ecological disciplines to frame core aspects of a sustainable, resilient ecosystem. Approaching forest management in the Sierra Nevada and southern Cascade Range in a manner that promotes socioecological resilience and sustains important forest values requires consideration of not only the ecological, but also the...

Editorial: a scientifically rigorous and user-friendly Rangeland Ecology & Management

USDA-ARS?s Scientific Manuscript database

Rangeland Ecology and Management (REM) is the premier journal for communication of science-based knowledge and for fostering both innovation and rigor in our stewardship of the world’s rangelands. REM is critical to the mission of the Society for Range Management and has had increasing scientific im...

Sagebrush identification, ecology, and palatability relative to sage-grouse

Treesearch

Roger Rosentreter

2005-01-01

Basic identification keys and comparison tables for 23 low and big sagebrush (Artemisia) taxa are presented. Differences in sagebrush ecology, soil temperature regimes, geographic range, palatability, mineralogy, and chemistry are discussed. Coumarin, a chemical produced in the glands of some Artemisia species, causes UV-light fluorescence of the...

Freshwater sculpins: phylogenetics to ecology

Treesearch

Susan B. Adams; David A. Schmetterling

2007-01-01

Freshwater sculpins (Cottidae) are a diverse and ecologically important component of cool- and coldwater ecosystems throughout the northern hemisphere. More than 60 sculpin species occur in a variety of habitats, and sculpin distributions range from highly localized to widespread. Despite the frequently high biomass of sculpins and their numerous ecosystem functions,...

Ecological drivers of variation in tool-use frequency across sea otter populations

USGS Publications Warehouse

Fujii, Jessica; Ralls, Katherine; Tinker, M. Tim

2015-01-01

Sea otters are well-known tool users, employing objects such as rocks or shells to break open hard-shelled invertebrate prey. However, little is known about how the frequency of tool use varies among sea otter populations and the factors that drive these differences. We examined 17 years of observational data on prey capture and tool use from 8 sea otter populations ranging from southern California to the Aleutian Islands in Alaska. There were significant differences in the diets of these populations as well as variation in the frequency of tool use. Sea otters at Amchitka Island, Alaska, used tools on less than 1% of dives that resulted in the capture of prey compared with approximately 16% in Monterey, California. The percentage of individuals in the population that used tools ranged from 10% to 93%. In all populations, marine snails and thick-shelled bivalves were most likely to be associated with tool use, whereas soft-bodied prey items such as worms and sea stars were the least likely. The probability that a tool would be used on a given prey type varied across populations. The morphology of the prey item being handled and the prevalence of various types of prey in local diets were major ecological drivers of tool use: together they accounted for about 64% of the variation in tool-use frequency among populations. The remaining variation may be related to changes in the relative costs and benefits to an individual otter of learning to use tools effectively under differing ecological circumstances.

Estimation of carbon sequestration in China’s forests induced by atmospheric wet nitrogen deposition using the principles of ecological stoichiometry

NASA Astrophysics Data System (ADS)

Zhu, Jianxing; He, Nianpeng; Zhang, Jiahui; Wang, Qiufeng; Zhao, Ning; Jia, Yanlong; Ge, Jianping; Yu, Guirui

2017-11-01

The worldwide development of industry and agriculture has generated noticeable increases in atmospheric nitrogen (N) deposition, significantly altering the global N cycle. These changes might affect the global carbon (C) cycle by enhancing forest C sequestration. Here, we used a series of datasets from eight typical forests along the north-south transect of eastern China (NSTEC). These datasets contained information on community structure, C and N concentrations in the soil and the organs (leaf, branch, stem, and fine-root) of 877 plant species, and atmospheric wet N deposition. Using the biomass weighting method, we scaled up the C:N ratios from the organ level to the ecosystem level, and evaluated the C sequestration rate (CSRN) in response to wet N deposition and N use efficiency (NUE) in China’s forests based on the principles of ecological stoichiometry. Our results showed that atmospheric wet N deposition had a modest impact on forest C storage. Specifically, mean CSRN was estimated as 231 kg C ha-1 yr-1 (range: 32.7-507.1 kg C ha-1 yr-1), accounting for 2.1% of NPP and 4.6% of NEP at the ecosystem level. The NUEeco of atmospheric N deposition ranged from 9.6-27.7 kg C kg-1 N, and increased with increasing latitude from subtropical to cold-temperate forests in China (P < 0.05). This study provides a new approach for estimating the effect of atmospheric deposition on forest C sequestration based on the principles of ecological stoichiometry.

Ecological filtering by a dominant herb selects for shade tolerance in the tree seedling community of coastal dune forest.

PubMed

Tsvuura, Zivanai; Griffiths, Megan E; Gunton, Richard M; Franks, Peter J; Lawes, Michael J

2010-12-01

The regeneration niche is commonly partitioned along a gradient from shade-tolerant to shade-intolerant species to explain plant community assembly in forests. We examined the shade tolerance of tree seedlings in a subtropical coastal forest to determine whether the ecological filtering effect of a dominant, synchronously monocarpic herb (Isoglossa woodii) selects for species at either end of the light response continuum during the herb's vegetative and reproductive phases. Photosynthetic characteristics of seedlings of 20 common tree species and the herb were measured. Seedlings were grown in the greenhouse at 12-14% irradiance, and their light compensation points measured using an open-flow gas exchange system. The light compensation points for the tree species were low, falling within a narrow range from 2.1 ± 0.8 μmol m(-2) s(-1) in Celtis africana to 6.4 ± 0.7 μmol m(-2) s(-1) in Allophylus natalensis, indicating general shade tolerance, consistent with a high and narrow range of apparent quantum yield among species (0.078 ± 0.002 mol CO(2) mol(-1) photon). Rates of dark respiration were significantly lower in a generalist pioneer species (Acacia karroo) than in a forest pioneer (C. africana), or in late successional phase forest species. We argue that the general shade tolerance, and phenotypic clustering of shade tolerance, in many tree species from several families in this system, is a result of ecological filtering by the prevailing low light levels beneath the I. woodii understorey, which excludes most light-demanding species from the seedling community.

Stationary moments, diffusion limits, and extinction times for logistic growth with random catastrophes.

PubMed

Schlomann, Brandon H

2018-06-06

A central problem in population ecology is understanding the consequences of stochastic fluctuations. Analytically tractable models with Gaussian driving noise have led to important, general insights, but they fail to capture rare, catastrophic events, which are increasingly observed at scales ranging from global fisheries to intestinal microbiota. Due to mathematical challenges, growth processes with random catastrophes are less well characterized and it remains unclear how their consequences differ from those of Gaussian processes. In the face of a changing climate and predicted increases in ecological catastrophes, as well as increased interest in harnessing microbes for therapeutics, these processes have never been more relevant. To better understand them, I revisit here a differential equation model of logistic growth coupled to density-independent catastrophes that arrive as a Poisson process, and derive new analytic results that reveal its statistical structure. First, I derive exact expressions for the model's stationary moments, revealing a single effective catastrophe parameter that largely controls low order statistics. Then, I use weak convergence theorems to construct its Gaussian analog in a limit of frequent, small catastrophes, keeping the stationary population mean constant for normalization. Numerically computing statistics along this limit shows how they transform as the dynamics shifts from catastrophes to diffusions, enabling quantitative comparisons. For example, the mean time to extinction increases monotonically by orders of magnitude, demonstrating significantly higher extinction risk under catastrophes than under diffusions. Together, these results provide insight into a wide range of stochastic dynamical systems important for ecology and conservation. Copyright © 2018 Elsevier Ltd. All rights reserved.

Physiological responses of Yellowstone bison to winter nutritional deprivation

USGS Publications Warehouse

DelGiudice, Glenn D.; Singer, Francis J.; Seal, Ulysses S.; Bowser, Gillian

1994-01-01

Because nutrition is critically related to other aspects of bison (Bison bison) ecology, and the winter ranges inhabited by bison in Yellowstone National Park (YNP) are ecologically diverse, it was important to determine if nutritional deprivation differences occurred among winter ranges. We used chemistry profiles of urine suspended in snow to compare nutritional deprivation of bison from January to April 1988 on 4 sampling areas of 3 winter ranges in YNP. Declining (P < 0.001) trends of urinary potassium: creatinine ratios in bison on all 4 sampling areas indicated progressive nutritional deprivation through late March. Concurrent increases (P ≤ 0.001) in mean urea nitrogen: creatinine ratios from late February through late march in 3 of 4 areas suggested that increased net catabolism was occurring. Diminished creatinine ratios of sodium and phosphorus reflected low dietary intake of these minerals throughout winter. Mean values and trends of urinary characteristics indicated nutritional deprivation varied among 3 winter ranges in YNP. Continued physiological monitoring of nutritional deprivation, along with detailed examination of other aspects of the bison's ecology, will provide greater insight into the role of ungulate nutrition in the dynamics of such a complex system and improve management.

Quantifying Ecological Literacy in an Adult Western Community: The Development and Application of a New Assessment Tool and Community Standard

PubMed Central

Pitman, Sheryn D.; Daniels, Christopher B.

2016-01-01

Knowledge and understanding about how the Earth functions and supports life create the foundation for ecological literacy. Industrialisation, urbanisation and population growth have resulted in changed relationships between many human communities and the natural world. A potential consequence is a compromised capability to make well-informed decisions about how to live sustainably. To gain a measure of ecological literacy within the South Australian community, we collaborated with senior scientists and educators to develop and apply an instrument with the capacity to determine indicative levels of ecological knowledge and understanding. A formal, variable credit, multiple-choice assessment instrument was distributed online to groups and individuals within diverse community sectors and industries. Quantitative analyses of scores indicated that levels of ecological knowledge and understanding within a self-selected sample of over one thousand individuals ranged from very low to extremely high, with the majority of respondents achieving moderate to high scores. This instrument has a demonstrated capacity to determine indicative levels of ecological literacy within and between individuals and groups. It is able to capture mastery of ecological knowledge and understanding achieved through both formal and informal pathways. Using the results, we have been able to establish a range of standards and an aspirational target score for the South Australian community. The value of this work is in its potential to deliver insights into relationships between humans and the rest of the natural world, and into characteristics of eco-literate individuals and communities, that might not otherwise emerge. PMID:26938258

Quantifying Ecological Literacy in an Adult Western Community: The Development and Application of a New Assessment Tool and Community Standard.

PubMed

Pitman, Sheryn D; Daniels, Christopher B

2016-01-01

Knowledge and understanding about how the Earth functions and supports life create the foundation for ecological literacy. Industrialisation, urbanisation and population growth have resulted in changed relationships between many human communities and the natural world. A potential consequence is a compromised capability to make well-informed decisions about how to live sustainably. To gain a measure of ecological literacy within the South Australian community, we collaborated with senior scientists and educators to develop and apply an instrument with the capacity to determine indicative levels of ecological knowledge and understanding. A formal, variable credit, multiple-choice assessment instrument was distributed online to groups and individuals within diverse community sectors and industries. Quantitative analyses of scores indicated that levels of ecological knowledge and understanding within a self-selected sample of over one thousand individuals ranged from very low to extremely high, with the majority of respondents achieving moderate to high scores. This instrument has a demonstrated capacity to determine indicative levels of ecological literacy within and between individuals and groups. It is able to capture mastery of ecological knowledge and understanding achieved through both formal and informal pathways. Using the results, we have been able to establish a range of standards and an aspirational target score for the South Australian community. The value of this work is in its potential to deliver insights into relationships between humans and the rest of the natural world, and into characteristics of eco-literate individuals and communities, that might not otherwise emerge.

Sewage impacts coral reefs at multiple levels of ecological organization.

PubMed

Reopanichkul, Pasinee; Schlacher, Thomas A; Carter, R W; Worachananant, Suchai

2009-09-01

Against a backdrop of rising sea temperatures and ocean acidification which pose global threats to coral reefs, excess nutrients and turbidity continue to be significant stressors at regional and local scales. Because interventions usually require local data on pollution impacts, we measured ecological responses to sewage discharges in Surin Marine Park, Thailand. Wastewater disposal significantly increased inorganic nutrients and turbidity levels, and this degradation in water quality resulted in substantial ecological shifts in the form of (i) increased macroalgal density and species richness, (ii) lower cover of hard corals, and (iii) significant declines in fish abundance. Thus, the effects of nutrient pollution and turbidity can cascade across several levels of ecological organization to change key properties of the benthos and fish on coral reefs. Maintenance or restoration of ecological reef health requires improved wastewater management and run-off control for reefs to deliver their valuable ecosystems services.

Community Ecology of Container Mosquitoes (Diptera: Culicidae) in Virginia Following Invasion by Aedes japonicus

PubMed Central

ARMISTEAD, JENNIFER S.; NISHIMURA, NAOYA; ARIAS, JORGE R.; LOUNIBOS, L. PHILIP

2012-01-01

The success of an invasive species in a new region depends on its interactions with ecologically similar resident species. Invasions by disease vector mosquitoes are important as they may have ecological and epidemiological consequences. Potential interactions of a recent invasive mosquito, Aedes japonicus Theobald, with resident species in Virginia were evaluated by sampling larvae from containers and trapping adults. Distinct species compositions were observed for artificial containers and rock pools, with Ae. albopictus most abundant in the former and Ae. japonicus in the latter. However, these two species were found to co-occur in 21.2% of containers sampled. Among the six mosquito species most common in containers from May through September, 2006, only interspecific associations of Ae.japonicus with Aedesalbopictus(Skuse) and Aedestriseriatus(Say) were significant, and both were negative. In addition to differences in habitat preference, mean crowding estimates suggest that interspecific repulsion may contribute to the significant negative associations observed between these species. High relative abundances of late instars and pupae of Ae. japonicus seem to provide this species with a mechanism of evading competition with Ae. albopictus, facilitating their coexistence in artificial containers. Although annual fluctuations were observed, trends in adult populations over a 6-yr period provide no evidence of declines. In summary, this survey of diverse container types and all life stages provided only limited evidence for competitive displacements or reductions of resident container species by Ae. japonicus, as observed elsewhere in its invasive range. PMID:23270159

Ecological differentiation, lack of hybrids involving diploids, and asymmetric gene flow between polyploids in narrow contact zones of Senecio carniolicus (syn. Jacobaea carniolica, Asteraceae).

PubMed

Hülber, Karl; Sonnleitner, Michaela; Suda, Jan; Krejčíková, Jana; Schönswetter, Peter; Schneeweiss, Gerald M; Winkler, Manuela

2015-03-01

Areas of immediate contact of different cytotypes offer a unique opportunity to study evolutionary dynamics within heteroploid species and to assess isolation mechanisms governing coexistence of cytotypes of different ploidy. The degree of reproductive isolation of cytotypes, that is, the frequency of heteroploid crosses and subsequent formation of viable and (partly) fertile hybrids, plays a crucial role for the long-term integrity of lineages in contact zones. Here, we assessed fine-scale distribution, spatial clustering, and ecological niches as well as patterns of gene flow in parental and hybrid cytotypes in zones of immediate contact of di-, tetra-, and hexaploid Senecio carniolicus (Asteraceae) in the Eastern Alps. Cytotypes were spatially separated also at the investigated microscale; the strongest spatial separation was observed for the fully interfertile tetra- and hexaploids. The three main cytotypes showed highly significant niche differences, which were, however, weaker than across their entire distribution ranges in the Eastern Alps. Individuals with intermediate ploidy levels were found neither in the diploid/tetraploid nor in the diploid/hexaploid contact zones indicating strong reproductive barriers. In contrast, pentaploid individuals were frequent in the tetraploid/hexaploid contact zone, albeit limited to a narrow strip in the immediate contact zone of their parental cytotypes. AFLP fingerprinting data revealed introgressive gene flow mediated by pentaploid hybrids from tetra- to hexaploid individuals, but not vice versa. The ecological niche of pentaploids differed significantly from that of tetraploids but not from hexaploids.

Controlled Ecological Life Support Systems: CELSS '89 Workshop

NASA Technical Reports Server (NTRS)

Macelroy, Robert D. (Editor)

1990-01-01

Topics discussed at NASA's Controlled Ecological Life Support Systems (CELSS) workshop concerned the production of edible biomass. Specific areas of interest ranged from the efficiency of plant growth, to the conversion of inedible plant material to edible food, to the use of plant culture techniques. Models of plant growth and whole CELSS systems are included. The use of algae to supplement and improve dietary requirements is addressed. Flight experimentation is covered in topics ranging from a Salad Machine for use on the Space Station Freedom to conceptual designs for a lunar base CELSS.

Challenges, developments and perspectives in intermittent ...

EPA Pesticide Factsheets

Although more than half the world's river networks comprise channels that periodically cease to flow and dry [intermittent rivers (IRs)], river ecology was largely developed from and for perennial systems. Ecological knowledge of IRs is rapidly increasing, so there is a need to synthesise this knowledge and deepen ecological understanding.In this Special Issue, we bring together 13 papers spanning observational case studies, field and laboratory experiments and reviews to guide research and management in this productive field of freshwater science. We summarise new developments in IR ecology, identify research gaps and needs, and address how the study of IRs as highly dynamic ecosystems informs ecological understanding more broadly.This series of articles reveals that contemporary IR ecology is a multifaceted and maturing field of research at the interface between aquatic and terrestrial ecology. This research contributes to fresh water and general ecology by testing concepts across a range of topics, including disturbance ecology, metacommunity ecology and coupled aquatic-terrestrial ecosystems.Drying affects flow continuity through time and flow connectivity across longitudinal, lateral and vertical dimensions of space, which aligns well with the recent emphasis of mainstream ecology on meta-system perspectives. Although most articles here focus on the wet phase, there is growing interest in dry phases, and in the terrestrial vegetation and invertebrate assemb

75 years of dryland science: Trends and gaps in arid ecology literature.

PubMed

Greenville, Aaron C; Dickman, Chris R; Wardle, Glenda M

2017-01-01

Growth in the publication of scientific articles is occurring at an exponential rate, prompting a growing need to synthesise information in a timely manner to combat urgent environmental problems and guide future research. Here, we undertake a topic analysis of dryland literature over the last 75 years (8218 articles) to identify areas in arid ecology that are well studied and topics that are emerging. Four topics-wetlands, mammal ecology, litter decomposition and spatial modelling, were identified as 'hot topics' that showed higher than average growth in publications from 1940 to 2015. Five topics-remote sensing, climate, habitat and spatial, agriculture and soils-microbes, were identified as 'cold topics', with lower than average growth over the survey period, but higher than average numbers of publications. Topics in arid ecology clustered into seven broad groups on word-based similarity. These groups ranged from mammal ecology and population genetics, broad-scale management and ecosystem modelling, plant ecology, agriculture and ecophysiology, to populations and paleoclimate. These patterns may reflect trends in the field of ecology more broadly. We also identified two broad research gaps in arid ecology: population genetics, and habitat and spatial research. Collaborations between population genetics and ecologists and investigations of ecological processes across spatial scales would contribute profitably to the advancement of arid ecology and to ecology more broadly.

Recent vegetation phenology variability and wild reindeer migration in Hardangervidda plateau (Norway)

NASA Astrophysics Data System (ADS)

Courault, Romain; Franclet, Alexiane; Bourrand, Kévin; Bilodeau, Clélia; Saïd, Sonia; Cohen, Marianne

2018-05-01

More than others, arctic ecosystems are affected by consequences of global climate changes. The herbivorous plays numerous roles both in Scandinavian natural and cultural landscapes (Forbes et al., 2007). Wild reindeer (Rangifer tarandus L.) herds in Hardangervidda plateau (Norway) constitute one of the isolated populations along Fennoscandia mountain range. The study aims to understand temporal and spatial variability of intra- and inter-annual home ranges extent and geophysical properties. We then characterize phenological variability with Corine Land Cover ecological habitat assessment and bi-monthly NDVI index (MODIS 13Q1, 250 m). Thirdly, we test relationships between reindeer's estimated densities and geophysical factors. All along the study, a Python toolbox ("GRiD") has been mounted and refined to fit with biogeographical expectancies. The toolbox let user's choice of inputs and facilitate then the gathering of raster datasets with given spatial extent of clipping and resolution. The grid generation and cells extraction gives one tabular output, allowing then to easily compute complex geostatistical analysis with regular spreadsheets. Results are based on reindeer's home ranges, associated extent (MODIS tile) and spatial resolution (250 m). Spatial mismatch of 0.6 % has been found between ecological habitat when comparing raw (100 m2) and new dataset (250 m2). Inter-annual home ranges analysis describes differences between inter-seasonal migrations (early spring, end of the summer) and calving or capitalizing times. For intra-annual home ranges, significant correlations have been found between reindeer's estimated densities and both altitudes and phenology. GRiD performance and biogeographical results suggests 1) to enhance geometric accuracy 2) better examine links between estimated densities and NDVI.

Ethnic differences in ecological concerns: Spanish-speaking Hispanics are more concerned than others

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burger, Joanna; Greenberg, Michael; Edward J. Bloustein School of Planning and Public Policy, Rutgers University, 33 Livingston Avenue, New Brunswick, New Jersey 08901-1958

We postulated that environmental concern encompasses a wide range of different issues, often lumping pollution with habitat loss (or land use) and ecological resources (fish and wildlife). In this paper, we compare perceptions about a range of environmental and ecological resource issues, and explore ethnic/racial differences. We surveyed 1513 residents of New Jersey about 'environmental concerns', using both general environmental questions (two questions: How serious are environmental problems in New Jersey? Are you concerned about the loss of open space?) and ecological resource questions (12 questions: e.g., how important is planting trees in your neighborhood, how concerned are you aboutmore » loss of breeding and feeding habitat for fish and birds?) in New Jersey. Not all concerns were rated equally. For the ecological questions, there were no ethnic differences in concerns over preserving areas around water supplies, loss of places to hunt and fish, and loss of places for quiet walks and cycling, but there were for the other 9 ecological concerns. For eight of these nine concerns, Spanish-speaking Hispanics were more concerned than others (including English-speaking Hispanics). We divided the ecological resources into three categories: ecological services (clean water and safety), ecological resources (fish and wildlife), and recreational services. The strongest correlates of people's association with enlarging and enhancing recreational services were Spanish-speaking Hispanics, who are supportive of regulations and believe local government is not doing enough for environmental problems. People concerned about the loss of ecological resources and open space believe the federal government and the state are not doing enough for the environment, were non-Hispanic White, want continued environmental regulations, were longer-term residents, were high school graduates, and were older (45-54 years). People interested in ecological services were college-educated, non-White, not rich, females that did not trust DEP's environmental actions, and thought the state was not doing enough environmentally. There was a high correlation between general environmental concern and the ecological resource variables for the population overall, and for each ethnic group. Overall, only 39% of the subjects were very concerned about the seriousness of environmental problems in New Jersey, yet from 36% to 81% of the people were very concerned about 11 of 12 ecological issues. This indicates that people respond different to the term 'environmental problems' compared to specific 'ecological resource' issues. The greatest concern (81%) was for preserving areas around water supplies and cleaning up garbage in the parks, and the least concern was for the loss of places to hunt and fish (26%). Our results indicate that people distinguish between general environmental concern and ecological concerns, as well as distinguishing ecological services from ecological resources.« less

An ecological systems approach to bullying behaviors among middle school students in the United States.

PubMed

Lee, Chang-Hun

2011-05-01

The aim of this study is to identify an ecological prediction model of bullying behaviors. Based on an ecological systems theory, this study identifies significant factors influencing bullying behaviors at different levels of middle and high school. These levels include the microsystem, mesosystem, exosystem, and macrosystem. More specifically, the ecological factors investigated in this multilevel analysis are individual traits, family experiences, parental involvement, school climate, and community characteristics. Using data collected in 2008 from 485 randomly selected students in a school district, this study identifies a best-fitting structural model of bullying behavior. Findings suggest that the ecological model accounted for a high portion of variance in bullying behaviors. All of the ecological systems as well as individual traits were found to be significant influences on bullying behaviors either directly or indirectly.

LiDAR: Providing structure

USGS Publications Warehouse

Vierling, Lee A.; Martinuzzi, Sebastián; Asner, Gregory P.; Stoker, Jason M.; Johnson, Brian R.

2011-01-01

Since the days of MacArthur, three-dimensional (3-D) structural information on the environment has fundamentally transformed scientific understanding of ecological phenomena (MacArthur and MacArthur 1961). Early data on ecosystem structure were painstakingly laborious to collect. However, as reviewed and reported in recent volumes of Frontiers(eg Vierling et al. 2008; Asner et al.2011), advances in light detection and ranging (LiDAR) remote-sensing technology provide quantitative and repeatable measurements of 3-D ecosystem structure that enable novel ecological insights at scales ranging from the plot, to the landscape, to the globe. Indeed, annual publication of studies using LiDAR to interpret ecological phenomena increased 17-fold during the past decade, with over 180 new studies appearing in 2010 (ISI Web of Science search conducted on 23 Mar 2011: [{lidar AND ecol*} OR {lidar AND fores*} OR {lidar AND plant*}]).

Industrial ecology: reflections on a colloquium.

PubMed Central

Ausubel, J H

1992-01-01

Industrial ecology is the network of all industrial processes as they may interact with each other and live off each other, not only in the economic sense, but also in the sense of direct use of each other's material and energy wastes and products. This paper, which reflects upon the papers and discussions at the National Academy of Sciences Colloquium on Industrial Ecology on May 20-21, 1991, is structured around 10 questions. Do sociotechnical systems have long-range environmental goals? How is the concept of industrial ecology useful and timely? What are environmental technologies? Is there a systematic way to choose among alternatives for improving the ecology of technologies? What are ways to measure performance with respect to industrial ecology? What are the sources and rates of innovation in environmental technologies? How is the market economy performing with respect to industrial ecology? What will be the effect of the ecological modernization of the developed nations of the North on the developing countries of the South? How can creative interaction on environmental issues be fostered among diverse social groups? How must research and education change? PMID:11607273

Linking Compositional and Functional Predictions to Decipher the Biogeochemical Significance in DFAA Turnover of Abundant Bacterioplankton Lineages in the North Sea.

PubMed

Wemheuer, Bernd; Wemheuer, Franziska; Meier, Dimitri; Billerbeck, Sara; Giebel, Helge-Ansgar; Simon, Meinhard; Scherber, Christoph; Daniel, Rolf

2017-11-05

Deciphering the ecological traits of abundant marine bacteria is a major challenge in marine microbial ecology. In the current study, we linked compositional and functional predictions to elucidate such traits for abundant bacterioplankton lineages in the North Sea. For this purpose, we investigated entire and active bacterioplankton composition along a transect ranging from the German Bight to the northern North Sea by pyrotag sequencing of bacterial 16S rRNA genes and transcripts. Functional profiles were inferred from 16S rRNA data using Tax4Fun. Bacterioplankton communities were dominated by well-known marine lineages including clusters/genera that are affiliated with the Roseobacter group and the Flavobacteria . Variations in community composition and function were significantly explained by measured environmental and microbial properties. Turnover of dissolved free amino acids (DFAA) showed the strongest correlation to community composition and function. We applied multinomial models, which enabled us to identify bacterial lineages involved in DFAA turnover. For instance, the genus Planktomarina was more abundant at higher DFAA turnover rates, suggesting its vital role in amino acid degradation. Functional predictions further indicated that Planktomarina is involved in leucine and isoleucine degradation. Overall, our results provide novel insights into the biogeochemical significance of abundant bacterioplankton lineages in the North Sea.

Diet and feeding ecology of invasive icefish Neosalanx taihuensis in Erhai Lake, a Chinese plateau mesoeutrophicated lake

NASA Astrophysics Data System (ADS)

Hu, Cuilin; Guo, Longgen; Wang, Shengrui

2015-03-01

A comprehensive study of the invasive icefish Neosalanx taihuensis feeding ecology in Erhai Lake was conducted from November 2009 to October 2010. Prey items in the guts of the icefish sampled varied significantly according to season. This finding suggests a relationship between fluctuations in available prey in the environment and selective feeding by icefish. N. taihuensis preferred large-sized zooplankton, such as Daphnia and calanoids. Additionally, the gut fullness values differed significantly ( P<0.001) among sampling times. To compare the values at different times, samples were taken over a 24 h period every 2 months for the entire year. The feeding activities of the fish were concentrated either in the morning (8:00) and/or at dusk (20:00), except in September 2010. This finding can be explained primarily by the variation in optimum light intensity. Daily N. taihuensis zooplankton consumption varied significantly, both diurnally and among seasons. The daily consumption values ranged from 0.089 to 0.237 g (wet weight) per 100 g wet fish weight in temperatures between 11.50°C and 24.68°C. This is the first report of diel feeding periodicity and daily food consumption of icefish in their invaded ecosystems.

Ecomorphology of orbit orientation and the adaptive significance of binocular vision in primates and other mammals.

PubMed

Heesy, Christopher P

2008-01-01

Primates are characterized by forward-facing, or convergent, orbits and associated binocular field overlap. Hypotheses explaining the adaptive significance of these traits often relate to ecological factors, such as arboreality, nocturnal visual predation, or saltatory locomotion in a complex nocturnal, arboreal environment. This study re-examines the ecological factors that are associated with high orbit convergence in mammals. Orbit orientation data were collected for 321 extant taxa from sixteen orders of metatherian (marsupial) and eutherian mammals. These taxa were coded for activity pattern, degree of faunivory, and substrate preference. Results demonstrate that nocturnal and cathemeral mammals have significantly more convergent orbits than diurnal taxa, both within and across orders. Faunivorous eutherians (both nocturnal and diurnal) have higher mean orbit convergence than opportunistically foraging or non-faunivorous taxa. However, substrate preference is not associated with higher orbit convergence and, by extension, greater binocular visual field overlap. These results are consistent with the hypothesis that mammalian predators evolved higher orbit convergence, binocular vision, and stereopsis to counter camouflage in prey inhabiting a nocturnal environment. Strepsirhine primates have a range of orbit convergence values similar to nocturnal or cathemeral predatory non-primate mammals. These data are entirely consistent with the nocturnal visual predation hypothesis of primate origins. (c) 2007 S. Karger AG, Basel.

Contrasting PCB bioaccumulation patterns among Lake Huron lake trout reflect basin-specific ecology.

PubMed

Paterson, Gordon; Ryder, Mark; Drouillard, Ken G; Haffner, G Douglas

2016-01-01

This study collected multiple age classes of lake trout from Lake Huron's Main Basin, Georgian Bay, and North Channel regions to compare and contrast top predator polychlorinated biphenyl (PCB) bioaccumulation patterns in separate compartments of the same ecosystem. Sum PCB concentrations were highest for Main Basin (260 ± 24.9 ng g(-1) wet wt) fish, followed by Georgian Bay (74.6 ± 16.2 ng g(-1) ) and North Channel (42.0 ± 3.3 ng g(-1)) fish. Discriminant functions analysis of lake trout PCB profiles and stable carbon (δ(13)C) and nitrogen (δ(15)N) isotope values clearly distinguished fish by location, indicating high degrees of basin fidelity throughout their lifetimes in addition to highly contrasting PCB bioaccumulation profiles. These unique profiles were not attributable to significant differences in lake trout lipid contents (p = 0.856) or trophic position (δ(15)N; p = 0.334), with rainbow smelt representing the primary prey across the basins. Furthermore, significant differences were observed among the basins for the relationships between PCB biomagnification factors and hydrophobicity. An empirical model for predicting PCB biomagnification in Lake Huron lake trout indicated that basin-specific population growth rates and prey abundances were significant for explaining these contrasting patterns of PCB bioaccumulation. The results of the present study are fundamental for understanding the role of ecology in legacy persistent organic pollutant (POP) bioaccumulation. Specifically, ecosystem characteristics such as prey abundances, foraging ecology, and ultimately consumer growth can regulate the variability of legacy POP bioaccumulation as observed within and among a wide range of freshwater ecosystems. © 2015 SETAC.

Perspectives on why digital ecologies matter: combining population genetics and ecologically informed agent-based models with GIS for managing dipteran livestock pests.

PubMed

Peck, Steven L

2014-10-01

It is becoming clear that handling the inherent complexity found in ecological systems is an essential task for finding ways to control insect pests of tropical livestock such as tsetse flies, and old and new world screwworms. In particular, challenging multivalent management programs, such as Area Wide Integrated Pest Management (AW-IPM), face daunting problems of complexity at multiple spatial scales, ranging from landscape level processes to those of smaller scales such as the parasite loads of individual animals. Daunting temporal challenges also await resolution, such as matching management time frames to those found on ecological and even evolutionary temporal scales. How does one deal with representing processes with models that involve multiple spatial and temporal scales? Agent-based models (ABM), combined with geographic information systems (GIS), may allow for understanding, predicting and managing pest control efforts in livestock pests. This paper argues that by incorporating digital ecologies in our management efforts clearer and more informed decisions can be made. I also point out the power of these models in making better predictions in order to anticipate the range of outcomes possible or likely. Copyright © 2014 International Atomic Energy Agency 2014. Published by Elsevier B.V. All rights reserved.

Final recovery plan of the southwestern willow flycatcher (Empidonax traillii extimus)

Treesearch

Deborah M. Finch; Stephen I. Rothstein; Jon C. Boren; William L. Graf; Jerry L. Holechek; Barbara E. Kus; Robert M. Marshall; Molly M. Pohl; Susan J. Sferra; Mark K. Sogge; Julie C. Stromberg; Bradley A. Valentine; Mary J. Whitfield; Sartor O. Williams

2002-01-01

The Southwestern Willow Flycatcher Recovery Team is composed of a Technical Subgroup (pg. ii), six Implementation Subgroups (Appendix A), and a Tribal Working Group. The Technical Subgroup consists of 14 academic scientists, researchers, and resource managers with a wide range of expertise in avian biology and ecology, southwestern willow flycatcher ecology, cowbird...

Cumulative ecological and socioeconomic effects of forest policies in coastal Oregon.

Treesearch

T.A. Spies; K.N. Johnson; K.M. Burnett; J.L. Ohmann; B.C. McComb; G.H. Reeves; P. Bettinger; J.D. Kline; B. Garber-Yonts

2007-01-01

Forest biodiversity policies in multiownership landscapes are typically developed in an uncoordinated fashion with little consideration of their interactions or possible unintended cumulative effects. We conducted an assessment of some of the ecological and socioeconomic effects of recently enacted forest management policies in the 2.3-million-ha Coast Range...

Aspen's ecological role in the West

Treesearch

William H. Romme; Lisa Floyd-Hanna; David D. Hanna; Elisabeth Bartlett

2001-01-01

Aspen exhibits a variety of ecological roles. In southern Colorado, the 1880 landscape mosaic contained a range of stand ages, of which half were >70 years old and half were younger. Pure aspen stands in southern Colorado are widespread and may result from previous short fire intervals that eliminated local conifer seed sources. Aspen regeneration in northern...

Nonlinear dynamics in ecosystem response to climatic change: case studies and policy implications.

Treesearch

Virginia R. Burkett; Douglas A. Wilcox; Robert Stottlemeyer; Wylie Barrow; Dan Fagre; Jill Baron; Jeff Price; Jennifer L. Nielsen; Craig D. Allen; David L. Peterson; Greg Ruggerone; Thomas Doyle

2005-01-01

Many biological, hydrological, and geological processes are interactively linked in ecosystems. These ecological phenomena normally vary within bounded ranges, but rapid, nonlinear changes to markedly different conditions can be triggered by even small differences if threshold values are exceeded. Intrinsic and extrinsic ecological thresholds can lead to effects that...

Taking the pulse of a continent: Expanding site-based research infrastructure for regional- to continental-scale ecology

USDA-ARS?s Scientific Manuscript database

Many of the most dramatic and surprising effects of global change on ecological systems will occur across large spatial extents, from regions to continents. Multiple ecosystem types will be impacted across a range of interacting spatial and temporal scales. The ability of ecologists to understand an...

Baboquivari Mountain plants: Identification, ecology, and ethnobotany [Book Review

Treesearch

Rosemary L. Pendleton

2011-01-01

The Sky Islands of southern Arizona and northwestern Mexico make up a region that is rich, both biologically and culturally. These isolated mountain ranges, separated by desert "seas," contain a unique and diverse flora and have long been home to indigenous peoples of the southwestern US. This book, Baboquivari Mountain Plants: Identification, Ecology, and...

Applications of KHZ-CW Lidar in Ecological Entomology

NASA Astrophysics Data System (ADS)

Malmqvist, Elin; Brydegaard, Mikkel

2016-06-01

The benefits of kHz lidar in ecological entomology are explained. Results from kHz-measurements on insects, carried out with a CW-lidar system, employing the Scheimpflug principle to obtain range resolution, are presented. A method to extract insect events and analyze the large amount of lidar data is also described.

A Faculty-Development Model for Transforming Introductory Biology and Ecology Courses

ERIC Educational Resources Information Center

D'Avanzo, Charlene; Anderson, Charles W.; Hartley, Laurel M.; Pelaez, Nancy

2012-01-01

The Diagnostic Question Cluster (DQC) project integrates education research and faculty development to articulate a model for the effective transformation of introductory biology and ecology teaching. Over three years, faculty members from a wide range of institutions used active teaching and DQCs, a type of concept inventory, as pre- and…

Bat trait, genetic and pathogen data from large-scale investigations of African fruit bats, Eidolon helvum.

PubMed

Peel, Alison J; Baker, Kate S; Hayman, David T S; Suu-Ire, Richard; Breed, Andrew C; Gembu, Guy-Crispin; Lembo, Tiziana; Fernández-Loras, Andrés; Sargan, David R; Fooks, Anthony R; Cunningham, Andrew A; Wood, James L N

2016-08-01

Bats, including African straw-coloured fruit bats (Eidolon helvum), have been highlighted as reservoirs of many recently emerged zoonotic viruses. This common, widespread and ecologically important species was the focus of longitudinal and continent-wide studies of the epidemiological and ecology of Lagos bat virus, henipaviruses and Achimota viruses. Here we present a spatial, morphological, demographic, genetic and serological dataset encompassing 2827 bats from nine countries over an 8-year period. Genetic data comprises cytochrome b mitochondrial sequences (n=608) and microsatellite genotypes from 18 loci (n=544). Tooth-cementum analyses (n=316) allowed derivation of rare age-specific serologic data for a lyssavirus, a henipavirus and two rubulaviruses. This dataset contributes a substantial volume of data on the ecology of E. helvum and its viruses and will be valuable for a wide range of studies, including viral transmission dynamic modelling in age-structured populations, investigation of seasonal reproductive asynchrony in wide-ranging species, ecological niche modelling, inference of island colonisation history, exploration of relationships between island and body size, and various spatial analyses of demographic, morphometric or serological data.

Influences of climate change on the potential distribution of Lutzomyia longipalpis sensu lato (Psychodidae: Phlebotominae).

PubMed

Peterson, A Townsend; Campbell, Lindsay P; Moo-Llanes, David A; Travi, Bruno; González, Camila; Ferro, María Cristina; Ferreira, Gabriel Eduardo Melim; Brandão-Filho, Sinval P; Cupolillo, Elisa; Ramsey, Janine; Leffer, Andreia Mauruto Chernaki; Pech-May, Angélica; Shaw, Jeffrey J

2017-09-01

This study explores the present day distribution of Lutzomyia longipalpis in relation to climate, and transfers the knowledge gained to likely future climatic conditions to predict changes in the species' potential distribution. We used ecological niche models calibrated based on occurrences of the species complex from across its known geographic range. Anticipated distributional changes varied by region, from stability to expansion or decline. Overall, models indicated no significant north-south expansion beyond present boundaries. However, some areas suitable both at present and in the future (e.g., Pacific coast of Ecuador and Peru) may offer opportunities for distributional expansion. Our models anticipated potential range expansion in southern Brazil and Argentina, but were variably successful in anticipating specific cases. The most significant climate-related change anticipated in the species' range was with regard to range continuity in the Amazon Basin, which is likely to increase in coming decades. Rather than making detailed forecasts of actual locations where Lu. longipalpis will appear in coming years, our models make interesting and potentially important predictions of broader-scale distributional tendencies that can inform heath policy and mitigation efforts. Copyright © 2017 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reserved.

Ecological risk assessment based on IHA-RVA in the lower Xiaolangdi reservoir under changed hydrological situation

NASA Astrophysics Data System (ADS)

Bai, Tao; Ma, Pan-pan; Kan, Yan-bin; Huang, Qiang

2017-12-01

Ecological risk assessment of river is an important content for protection and improvement of ecological environment. In this paper, taking Xiaolangdi reservoir for example, ecological risk assessments are studied based on the 1956-1997 and 2002-2008 dairy runoff data as the pre and post of construction of Xiaolangdi reservoir. Considering pre and post hydrological regime of construction of Xiaolangdi, ecological risk assessment index systems of downstream are established based on Index of Hydrologic Alteration-Range of Variability Approach method (IHA-RVA), which considering characters of flow, time, frequency, delay and change rate. Then ecological risk fuzzy comprehensive evaluation assessment model downstream is established based on risk index and RVA method. The results show that after the construction of Xiaolangdi reservoir, ecological risk occurred in the downstream of Yellow River for changed hydrological indexes, such as monthly average flow, frequency and duration of extreme annual flow and so on, which probably destroy the whole ecosystems of the river. For example, ecological risk downstream of Xiaolangdi reservoir upgrade to level two in 2008. Research results make reference values and scientific basis both in ecological risk assessment and management of reservoir after construction.

Multi level ecological fitting: indirect life cycles are not a barrier to host switching and invasion.

PubMed

Malcicka, Miriama; Agosta, Salvatore J; Harvey, Jeffrey A

2015-09-01

Many invasive species are able to escape from coevolved enemies and thus enjoy a competitive advantage over native species. However, during the invasion phase, non-native species must overcome many ecological and/or physiological hurdles before they become established and spread in their new habitats. This may explain why most introduced species either fail to establish or remain as rare interstitials in their new ranges. Studies focusing on invasive species have been based on plants or animals where establishment requires the possession of preadapted traits from their native ranges that enables them to establish and spread in their new habitats. The possession of preadapted traits that facilitate the exploitation of novel resources or to colonize novel habitats is known as 'ecological fitting'. Some species have evolved traits and life histories that reflect highly intimate associations with very specific types of habitats or niches. For these species, their phenological windows are narrow, and thus the ability to colonize non-native habitats requires that a number of conditions need to be met in accordance with their more specialized life histories. Some of the strongest examples of more complex ecological fitting involve invasive parasites that require different animal hosts to complete their life cycles. For instance, the giant liver fluke, Fascioloides magna, is a major parasite of several species of ungulates in North America. The species exhibits a life cycle whereby newly hatched larvae must find suitable intermediate hosts (freshwater snails) and mature larvae, definitive hosts (ungulates). Intermediate and definitive host ranges of F. magna in its native range are low in number, yet this parasite has been successfully introduced into Europe where it has become a parasite of native European snails and deer. We discuss how the ability of these parasites to overcome multiple ecophysiological barriers represents an excellent example of 'multiple-level ecological fitting'. © 2015 John Wiley & Sons Ltd.

The response of big sagebrush (Artemisia tridentata) to interannual climate variation changes across its range.

PubMed

Kleinhesselink, Andrew R; Adler, Peter B

2018-05-01

Understanding how annual climate variation affects population growth rates across a species' range may help us anticipate the effects of climate change on species distribution and abundance. We predict that populations in warmer or wetter parts of a species' range should respond negatively to periods of above average temperature or precipitation, respectively, whereas populations in colder or drier areas should respond positively to periods of above average temperature or precipitation. To test this, we estimated the population sensitivity of a common shrub species, big sagebrush (Artemisia tridentata), to annual climate variation across its range. Our analysis includes 8,175 observations of year-to-year change in sagebrush cover or production from 131 monitoring sites in western North America. We coupled these observations with seasonal weather data for each site and analyzed the effects of spring through fall temperatures and fall through spring accumulated precipitation on annual changes in sagebrush abundance. Sensitivity to annual temperature variation supported our hypothesis: years with above average temperatures were beneficial to sagebrush in colder locations and detrimental to sagebrush in hotter locations. In contrast, sensitivity to precipitation did not change significantly across the distribution of sagebrush. This pattern of responses suggests that regional abundance of this species may be more limited by temperature than by precipitation. We also found important differences in how the ecologically distinct subspecies of sagebrush responded to the effects of precipitation and temperature. Our model predicts that a short-term temperature increase could produce an increase in sagebrush cover at the cold edge of its range and a decrease in cover at the warm edge of its range. This prediction is qualitatively consistent with predictions from species distribution models for sagebrush based on spatial occurrence data, but it provides new mechanistic insight and helps estimate how much and how fast sagebrush cover may change within its range. © 2018 by the Ecological Society of America.

Assessment of ecological security based on soil and water conservation: a case study from Gansu Province, China

NASA Astrophysics Data System (ADS)

Li, Z. J.; Tian, Q.; Song, L. L.

2016-08-01

In this study, the analytic hierarchy process (ahp), ecological security index(S) and PSR model were used to evaluate Gansu's ecological security based on the large number of survey data. The results indicated that Gansu's ecological security index increased from 0.31 in 1986 to 0.66 in 2013, which reflected ecological security was in sensitive state (0.7༞S≥⃒0.5). The main reason was that national policy on protecting the ecological environment has played a crucial role, especially the national project of returning farmland to forest and grass carried out in recent years. Moreover, the environmental issues such as the higher PM2.5, sand storms and climate extremes, had significantly improved people's environmental awareness in the study area. The regional difference of ecological security index was significant in Gansu Provinces, and the part of Yangtze river basin was higher than the part of Yellow River basin, whiles the in-land river basin was the lowest value. In a world, Gansu's ecological security had improved in recent years, but there was strong need for paying more attention to policy for ecological environment protection and increasing the propaganda to ensure the Gansu's ecological security in the future. This study will provide a scientific basis for the sustainable development of regional social economy and ecological environment.

A specialist-generalist classification of the arable flora and its response to changes in agricultural practices

PubMed Central

2010-01-01

Background Theory in ecology points out the potential link between the degree of specialisation of organisms and their responses to disturbances and suggests that this could be a key element for understanding the assembly of communities. We evaluated this question for the arable weed flora as this group has scarcely been the focus of ecological studies so far and because weeds are restricted to habitats characterised by very high degrees of disturbance. As such, weeds offer a case study to ask how specialization relates to abundance and distribution of species in relation to the varying disturbance regimes occurring in arable crops. Results We used data derived from an extensive national monitoring network of approximately 700 arable fields scattered across France to quantify the degree of specialisation of 152 weed species using six different ecological methods. We then explored the impact of the level of disturbance occurring in arable fields by comparing the degree of specialisation of weed communities in contrasting field situations. The classification of species as specialist or generalist was consistent between different ecological indices. When applied on a large-scale data set across France, this classification highlighted that monoculture harbour significantly more specialists than crop rotations, suggesting that crop rotation increases abundance of generalist species rather than sets of species that are each specialised to the individual crop types grown in the rotation. Applied to a diachronic dataset, the classification also shows that the proportion of specialist weed species has significantly decreased in cultivated fields over the last 30 years which suggests a biotic homogenization of agricultural landscapes. Conclusions This study shows that the concept of generalist/specialist species is particularly relevant to understand the effect of anthropogenic disturbances on the evolution of plant community composition and that ecological theories developed in stable environments are valid in highly disturbed environments such as agro-ecosystems. The approach developed here to classify arable weeds according to the breadth of their ecological niche is robust and applicable to a wide range of organisms. It is also sensitive to disturbance regime and we show here that recent changes in agricultural practices, i.e. increased levels of disturbance have favoured the most generalist species, hence leading to biotic homogenisation in arable landscapes. PMID:20809982

Ecological significance of residual exposures and effects from the Exxon Valdez oil spill.

PubMed

Harwell, Mark A; Gentile, John H

2006-07-01

An ecological significance framework is used to assess the ecological condition of Prince William Sound (PWS), Alaska, USA, in order to address the current management question: 17 y following the Exxon Valdez oil spill (EVOS), are there any remaining and continuing ecologically significant exposures or effects on the PWS ecosystem caused by EVOS? We examined the extensive scientific literature funded by the Exxon Valdez Trustees or by ExxonMobil to assess exposures and effects from EVOS. Criteria to assess ecological significance include whether a change in a valued ecosystem component (VEC) is sufficient to affect the structure, function, and/or health of the system and whether such a change exceeds natural variability. The EVOS occurred on 24 March 1989, releasing over 250,000 barrels of crude oil into PWS. Because PWS is highly dynamic, the residual oil was largely eliminated in the first few years, and now only widely dispersed, highly weathered, or isolated small pockets of residual contamination remain. Many other sources of polycyclic aromatic hydrocarbons (PAHs) exist in PWS from past or present human activities or natural oil seeps. Multiple-lines-of-evidence analyses indicate that residual PAHs from EVOS no longer represent an ecologically significant exposure risk to PWS. To assess the ecological significance of any residual effects from EVOS, we examined the literature on more than 20 VECs, including primary producers, filter feeders, fish and bird primary consumers, fish and bird top predators, a bird scavenger, mammalian primary consumers and top predators, biotic communities, ecosystem-level properties of trophodynamics and biogeochemical processes, and landscape-level properties of habitat mosaic and wilderness quality. None of these has any ecologically significant effects that are detectable at present, with the exception of 1 pod of orcas and possibly 1 subpopulation of sea otters; however, in both those cases, PWS-wide populations appear to have fully recovered. Many other stressors continue to affect PWS adversely, including climate and oceanographic variability, increased tourism and shipping, invasive species, the 1964 earthquake, and overexploitation of marine resources, with associated cascading effects on populations of PWS fish and predators. We conclude that the PWS ecosystem has now effectively recovered from EVOS.

Early Evolution of Modern Birds Structured by Global Forest Collapse at the End-Cretaceous Mass Extinction.

PubMed

Field, Daniel J; Bercovici, Antoine; Berv, Jacob S; Dunn, Regan; Fastovsky, David E; Lyson, Tyler R; Vajda, Vivi; Gauthier, Jacques A

2018-06-04

The fossil record and recent molecular phylogenies support an extraordinary early-Cenozoic radiation of crown birds (Neornithes) after the Cretaceous-Paleogene (K-Pg) mass extinction [1-3]. However, questions remain regarding the mechanisms underlying the survival of the deepest lineages within crown birds across the K-Pg boundary, particularly since this global catastrophe eliminated even the closest stem-group relatives of Neornithes [4]. Here, ancestral state reconstructions of neornithine ecology reveal a strong bias toward taxa exhibiting predominantly non-arboreal lifestyles across the K-Pg, with multiple convergent transitions toward predominantly arboreal ecologies later in the Paleocene and Eocene. By contrast, ecomorphological inferences indicate predominantly arboreal lifestyles among enantiornithines, the most diverse and widespread Mesozoic avialans [5-7]. Global paleobotanical and palynological data show that the K-Pg Chicxulub impact triggered widespread destruction of forests [8, 9]. We suggest that ecological filtering due to the temporary loss of significant plant cover across the K-Pg boundary selected against any flying dinosaurs (Avialae [10]) committed to arboreal ecologies, resulting in a predominantly non-arboreal post-extinction neornithine avifauna composed of total-clade Palaeognathae, Galloanserae, and terrestrial total-clade Neoaves that rapidly diversified into the broad range of avian ecologies familiar today. The explanation proposed here provides a unifying hypothesis for the K-Pg-associated mass extinction of arboreal stem birds, as well as for the post-K-Pg radiation of arboreal crown birds. It also provides a baseline hypothesis to be further refined pending the discovery of additional neornithine fossils from the Latest Cretaceous and earliest Paleogene. Copyright © 2018 Elsevier Ltd. All rights reserved.

Comparative ecologic relationships of saturated fat, sucrose, food groups, and a Mediterranean food pattern score to 50-year coronary heart disease mortality rates among 16 cohorts of the Seven Countries Study.

PubMed

Kromhout, Daan; Menotti, Alessandro; Alberti-Fidanza, Adalberta; Puddu, Paolo Emilio; Hollman, Peter; Kafatos, Anthony; Tolonen, Hanna; Adachi, Hisashi; Jacobs, David R

2018-05-17

We studied the ecologic relationships of food groups, macronutrients, eating patterns, and an a priori food pattern score (Mediterranean Adequacy Index: MAI) with long-term CHD mortality rates in the Seven Countries Study. Sixteen cohorts (12,763 men aged 40-59 years) were enrolled in the 1960s in seven countries (US, Finland, The Netherlands, Italy, Greece, former Yugoslavia: Croatia/Serbia, Japan). Dietary surveys were carried out at baseline and only in a subsample of each cohort. The average food consumption of each cohort was chemically analyzed for individual fatty acids and carbohydrates. Ecologic correlations of diet were computed across cohorts for 50-year CHD mortality rates; 97% of men had died in cohorts with 50-year follow-up. CHD death rates ranged 6.7-fold among cohorts. At baseline, hard fat was greatest in northern Europe, olive oil in Greece, meat in the US, sweet products in northern Europe and the US, and fish in Japan. The MAI was high in Mediterranean and Japanese cohorts. The 50-year CHD mortality rates of the cohorts were closely positively ecologically correlated (r = 0.68-0.92) with average consumption of hard fat, sweet products, animal foods, saturated fat, and sucrose, but not with naturally occurring sugars. Vegetable foods, starch, and the a priori pattern MAI were inversely correlated (r = -0.59 to -0.91) with CHD mortality rates. Long-term CHD mortality rates had statistically significant ecologic correlations with several aspects of diet consumed in the 1960s, the traditional Mediterranean and Japanese patterns being rich in vegetable foods, and low in sweet products and animal foods.

Ecological disequilibrium drives insect pest and pathogen accumulation in non-native trees

PubMed Central

Burgess, Treena I.; Le Roux, Johannes J.; Richardson, David M.; Slippers, Bernard; Wingfield, Michael J.

2017-01-01

Abstract Non-native trees have become dominant components of many landscapes, including urban ecosystems, commercial forestry plantations, fruit orchards and as invasives in natural ecosystems. Often, these trees have been separated from their natural enemies (i.e. insects and pathogens) leading to ecological disequilibrium, that is, the immediate breakdown of historically co-evolved interactions once introduced into novel environments. Long-established, non-native tree plantations provide useful experiments to explore the dimensions of such ecological disequilibria. We quantify the status quo of non-native insect pests and pathogens catching up with their tree hosts (planted Acacia, Eucalyptus and Pinus species) in South Africa, and examine which native South African enemy species utilize these trees as hosts. Interestingly, pines, with no confamilial relatives in South Africa and the longest residence time (almost two centuries), have acquired only one highly polyphagous native pathogen. This is in contrast to acacias and eucalypts, both with many native and confamilial relatives in South Africa that have acquired more native pathogens. These patterns support the known role of phylogenetic relatedness of non-native and native floras in influencing the likelihood of pathogen shifts between them. This relationship, however, does not seem to hold for native insects. Native insects appear far more likely to expand their feeding habits onto non-native tree hosts than are native pathogens, although they are generally less damaging. The ecological disequilibrium conditions of non-native trees are deeply rooted in the eco-evolutionary experience of the host plant, co-evolved natural enemies and native organisms from the introduced range. We should expect considerable spatial and temporal variation in ecological disequilibrium conditions among non-native taxa, which can be significantly influenced by biosecurity and management practices. PMID:28013250

Mercury concentrations in Pacific lamprey ( Entosphenus tridentatus ) and sediments in the Columbia River basin: Mercury in Columbia River Pacific lamprey

DOE Office of Scientific and Technical Information (OSTI.GOV)

Linley, Timothy; Krogstad, Eirik; Mueller, Robert

2016-06-21

We investigated mercury accumulation in Pacific lamprey and sediments in the Columbia River basin. Mercury concentrations in larval lamprey differed significantly among sample locations (P < 0.001) and were correlated with concentrations in sediments (r 2 = 0.83), whereas adult concentrations were highly variable (range 0.1–9.5 µg/g) and unrelated to holding time after collection. The results suggest that Pacific lamprey in the Columbia River basin may be exposed to mercury levels that have adverse ecological effects.

Nitrate reduction in sulfate-reducing bacteria.

PubMed

Marietou, Angeliki

2016-08-01

Sulfate-reducing bacteria (SRBs) gain their energy by coupling the oxidation of organic substrate to the reduction of sulfate to sulfide. Several SRBs are able to use alternative terminal electron acceptors to sulfate such as nitrate. Nitrate-reducing SRBs have been isolated from a diverse range of environments. In order to be able to understand the significance of nitrate reduction in SRBs, we need to examine the ecology and physiology of the nitrate-reducing SRB isolates. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Isotopic niches support the resource breadth hypothesis.

PubMed

Rader, Jonathan A; Newsome, Seth D; Sabat, Pablo; Chesser, R Terry; Dillon, Michael E; Martínez Del Rio, Carlos

2017-03-01

Because a broad spectrum of resource use allows species to persist in a wide range of habitat types, and thus permits them to occupy large geographical areas, and because broadly distributed species have access to more diverse resource bases, the resource breadth hypothesis posits that the diversity of resources used by organisms should be positively related with the extent of their geographic ranges. We investigated isotopic niche width in a small radiation of South American birds in the genus Cinclodes. We analysed feathers of 12 species of Cinclodes to test the isotopic version of the resource breadth hypothesis and to examine the correlation between isotopic niche breadth and morphology. We found a positive correlation between the widths of hydrogen and oxygen isotopic niches (which estimate breadth of elevational range) and widths of the carbon and nitrogen isotopic niches (which estimates the diversity of resources consumed, and hence of habitats used). We also found a positive correlation between broad isotopic niches and wing morphology. Our study not only supports the resource breadth hypothesis but it also highlights the usefulness of stable isotope analyses as tools in the exploration of ecological niches. It is an example of a macroecological application of stable isotopes. It also illustrates the importance of scientific collections in ecological studies. © 2016 The Authors. Journal of Animal Ecology © 2016 British Ecological Society.

Process-Driven Ecological Modeling for Landscape Change Analysis

NASA Astrophysics Data System (ADS)

Altman, S.; Reif, M. K.; Swannack, T. M.

2013-12-01

Landscape pattern is an important driver in ecosystem dynamics and can control system-level functions such as nutrient cycling, connectivity, biodiversity and carbon sequestration. However, the links between process, pattern and function remain ambiguous. Understanding the quantitative relationship between ecological processes and landscape pattern across temporal and spatial scales is vital for successful management and implementation of ecosystem-level projects. We used remote sensing imagery to develop critical landscape metrics to understand the factors influencing landscape change. Our study area, a coastal area in southwest Florida, is highly dynamic with critically eroding beaches and a range of natural and developed land cover types. Hurricanes in 2004 and 2005 caused a breach along the coast of North Captiva Island that filled in by 2010. We used a time series of light detection and ranging (lidar) elevation data and hyperspectral imagery from 2006 and 2010 to determine land cover changes. Landscape level metrics used included: Largest Patch Index, Class Area, Area-weighted mean area, Clumpiness, Area-weighted Contiguity Index, Number of Patches, Percent of landcover, Area-weighted Shape. Our results showed 1) 27% increase in sand/soil class as the channel repaired itself and shoreline was reestablished, 2) 40% decrease in the mudflat class area due to conversion to sand/soil and water, 3) 30% increase in non-wetland vegetation class as a result of new vegetation around the repaired channel, and 4) the water class only slightly increased though there was a marked increase in the patch size area. Thus, the smaller channels disappeared with the infilling of the channel, leaving much larger, less complex patches behind the breach. Our analysis demonstrated that quantification of landscape pattern is critical to linking patterns to ecological processes and understanding how both affect landscape change. Our proof of concept indicated that ecological processes can correlate to landscape pattern and that ecosystem function changes significantly as pattern changes. However, the number of links between landscape metrics and ecological processes are highly variable. Extensively studied processes such as biodiversity can be linked to numerous landscape metrics. In contrast, correlations between sediment cycling and landscape pattern have only been evaluated for a limited number of metrics. We are incorporating these data into a relational database linking landscape and ecological patterns, processes and metrics. The database will be used to parameterize site-specific landscape evolution models projecting how landscape pattern will change as a result of future ecosystem restoration projects. The model is a spatially-explicit, grid-based model that projects changes in community composition based on changes in soil elevations. To capture scalar differences in landscape change, local and regional landscape metrics are analyzed at each time step and correlated with ecological processes to determine how ecosystem function changes with scale over time.

The importance of ecological memory for trophic rewilding as an ecosystem restoration approach.

PubMed

Schweiger, Andreas H; Boulangeat, Isabelle; Conradi, Timo; Davis, Matt; Svenning, Jens-Christian

2018-06-06

Increasing human pressure on strongly defaunated ecosystems is characteristic of the Anthropocene and calls for proactive restoration approaches that promote self-sustaining, functioning ecosystems. However, the suitability of novel restoration concepts such as trophic rewilding is still under discussion given fragmentary empirical data and limited theory development. Here, we develop a theoretical framework that integrates the concept of 'ecological memory' into trophic rewilding. The ecological memory of an ecosystem is defined as an ecosystem's accumulated abiotic and biotic material and information legacies from past dynamics. By summarising existing knowledge about the ecological effects of megafauna extinction and rewilding across a large range of spatial and temporal scales, we identify two key drivers of ecosystem responses to trophic rewilding: (i) impact potential of (re)introduced megafauna, and (ii) ecological memory characterising the focal ecosystem. The impact potential of (re)introduced megafauna species can be estimated from species properties such as lifetime per capita engineering capacity, population density, home range size and niche overlap with resident species. The importance of ecological memory characterising the focal ecosystem depends on (i) the absolute time since megafauna loss, (ii) the speed of abiotic and biotic turnover, (iii) the strength of species interactions characterising the focal ecosystem, and (iv) the compensatory capacity of surrounding source ecosystems. These properties related to the focal and surrounding ecosystems mediate material and information legacies (its ecological memory) and modulate the net ecosystem impact of (re)introduced megafauna species. We provide practical advice about how to quantify all these properties while highlighting the strong link between ecological memory and historically contingent ecosystem trajectories. With this newly established ecological memory-rewilding framework, we hope to guide future empirical studies that investigate the ecological effects of trophic rewilding and other ecosystem-restoration approaches. The proposed integrated conceptual framework should also assist managers and decision makers to anticipate the possible trajectories of ecosystem dynamics after restoration actions and to weigh plausible alternatives. This will help practitioners to develop adaptive management strategies for trophic rewilding that could facilitate sustainable management of functioning ecosystems in an increasingly human-dominated world. © 2018 Cambridge Philosophical Society.

Micropollutants removal and health risk reduction in a water reclamation and ecological reuse system.

PubMed

Ma, Xiaoyan Y; Li, Qiyuan; Wang, Xiaochang C; Wang, Yongkun; Wang, Donghong; Ngo, Huu Hao

2018-07-01

As reclaimed water use is increasing, its safety attracts growing attention, particularly with respect to the health risks associated with the wide range of micropollutants found in the reclaimed water. In this study, sophisticated analysis was conducted for water samples from a water reclamation and ecological reuse system where domestic wastewater was treated using an anaerobic-anoxic-oxic unit followed by a membrane bioreactor (A 2 O-MBR), and the reclaimed water was used for replenishing a landscape lake. A total of 58 organic micropollutants were detected in the system, consisting of 13 polycyclic aromatic hydrocarbons (PAHs), 16 phenols, 3 pesticides, and 26 pharmaceuticals and personal care products (PPCPs). After treatment by the A 2 O-MBR process, effective removal of pesticides and phenols was achieved, while when the reclaimed water entered the landscape lake, PPCPs were further removed. From the physicochemical properties of micropollutants, it could be inferred that phenols and dichlorphos (the only pesticide with considerable concentration in the influent) would have been mainly removed by biodegradation and/or volatilization in the biological treatment process. Additionally, it is probable that sludge adsorption also contributed to the removal of dichlorphos. For the predominant PPCP removal in the landscape lake, various actions, such as adsorption, biodegradation, photolysis, and ecologically mediated processes (via aquatic plants and animals), would have played significant roles. However, according to their logK oc , logK ow and logD (pH = 8) values, it could be concluded that adsorption by suspended solids might be an important action. Although carcinogenic and non-carcinogenic risks associated with all the detected micropollutants were at negligible levels, the hazard quotients (HQs) of PPCPs accounted for 92.03%-97.23% of the HQ Total . With the significant removal of PPCPs through the ecological processes in the landscape lake, the safety of reclaimed water use could be improved. Therefore, the introduction of ecological unit into the water reclamation and reuse system could be an effective measure for health risk reduction posed by micropollutants. Copyright © 2018 Elsevier Ltd. All rights reserved.

The basis function approach for modeling autocorrelation in ecological data

USGS Publications Warehouse

Hefley, Trevor J.; Broms, Kristin M.; Brost, Brian M.; Buderman, Frances E.; Kay, Shannon L.; Scharf, Henry; Tipton, John; Williams, Perry J.; Hooten, Mevin B.

2017-01-01

Analyzing ecological data often requires modeling the autocorrelation created by spatial and temporal processes. Many seemingly disparate statistical methods used to account for autocorrelation can be expressed as regression models that include basis functions. Basis functions also enable ecologists to modify a wide range of existing ecological models in order to account for autocorrelation, which can improve inference and predictive accuracy. Furthermore, understanding the properties of basis functions is essential for evaluating the fit of spatial or time-series models, detecting a hidden form of collinearity, and analyzing large data sets. We present important concepts and properties related to basis functions and illustrate several tools and techniques ecologists can use when modeling autocorrelation in ecological data.

Potential ecological and human health risks of heavy metals in surface soils associated with iron ore mining in Pahang, Malaysia.

PubMed

Diami, Siti Merryan; Kusin, Faradiella Mohd; Madzin, Zafira

2016-10-01

The composition of heavy metals (and metalloid) in surface soils of iron ore mine-impacted areas has been evaluated of their potential ecological and human health risks. The mining areas included seven selected locations in the vicinity of active and abandoned iron ore-mining sites in Pahang, Malaysia. Heavy metals such as Fe, Mn, Cu, Zn, Co, Pb, Cr, Ni, and Cd and metalloid As were present in the mining soils of the studied area, while Cu was found exceeding the soil guideline value at all sampling locations. However, the assessment of the potential ecological risk index (RI) indicated low ecological risk (RI between 44 and 128) with respect to Cd, Pb, Cu, As, Zn, Co, and Ni in the surface soils. Contributions of potential ecological risk [Formula: see text]by metal elements to the total potential ecological RI were evident for Cd, As, Pb, and Cu. Contribution of Cu appears to be consistently greater in the abandoned mining area compared to active iron ore-mining site. For non-carcinogenic risk, no significant potential health risk was found to both children and adults as the hazard indices (HIs) were all below than 1. The lifetime cancer risk (LCR) indicated that As has greater potential carcinogenic risk compared to other metals that may induce carcinogenic effects such as Pb, Cr, and Cd, while the LCR of As for children fell within tolerable range for regulatory purposes. Irrespective of carcinogenic or non-carcinogenic risk, greater potential health risk was found among children (by an order of magnitude higher for most metals) compared to adults. The hazard quotient (HQ) and cancer risk indicated that the pathways for the risk to occur were found to be in the order of ingestion > dermal > inhalation. Overall, findings showed that some metals and metalloid were still present at comparable concentrations even long after cessation of the iron ore-mining activities.

The Welfare Implications of Using Exotic Tortoises as Ecological Replacements

PubMed Central

Griffiths, Christine J.; Zuël, Nicolas; Tatayah, Vikash; Jones, Carl G.; Griffiths, Owen; Harris, Stephen

2012-01-01

Background Ecological replacement involves the introduction of non-native species to habitats beyond their historical range, a factor identified as increasing the risk of failure for translocations. Yet the effectiveness and success of ecological replacement rely in part on the ability of translocatees to adapt, survive and potentially reproduce in a novel environment. We discuss the welfare aspects of translocating captive-reared non-native tortoises, Aldabrachelys gigantea and Astrochelys radiata, to two offshore Mauritian islands, and the costs and success of the projects to date. Methodology/Principal Findings Because tortoises are long-lived, late-maturing reptiles, we assessed the progress of the translocation by monitoring the survival, health, growth, and breeding by the founders. Between 2000 and 2011, a total of 26 A. gigantea were introduced to Ile aux Aigrettes, and in 2007 twelve sexually immature A. gigantea and twelve male A. radiata were introduced to Round Island, Mauritius. Annual mortality rates were low, with most animals either maintaining or gaining weight. A minimum of 529 hatchlings were produced on Ile aux Aigrettes in 11 years; there was no potential for breeding on Round Island. Project costs were low. We attribute the success of these introductions to the tortoises’ generalist diet, habitat requirements, and innate behaviour. Conclusions/Significance Feasibility analyses for ecological replacement and assisted colonisation projects should consider the candidate species’ welfare during translocation and in its recipient environment. Our study provides a useful model for how this should be done. In addition to serving as ecological replacements for extinct Mauritian tortoises, we found that releasing small numbers of captive-reared A. gigantea and A. radiata is cost-effective and successful in the short term. The ability to release small numbers of animals is a particularly important attribute for ecological replacement projects since it reduces the potential risk and controversy associated with introducing non-native species. PMID:22724012

[Distribution and risk assessment of mercury species in soil of the water-level-fluctuating zone in the Three Gorges Reservoir].

PubMed

Zhang, Cheng; Chen, Hong; Wang, Ding-Yong; Sun, Rong-Guo; Zhang, Jin-Yang

2014-03-01

To investigate pollution level and ecological risk of mercury in soils of the water-level-fluctuating zone in the Three Gorges Reservoir Region, 192 surface soil samples from 14 counties (districts) in Chongqing were obtained. Concentrations of THg and Hg species, bioavailable Hg were analyzed and discussed. Geoaccumulation index (I(geo)) and Håkanson potential ecological risk index (E(r)) were applied to assess the pollution status and potential ecological risk of THg and Hg species, respectively. The results showed that significant differences in the concentration of THg were found in soils of water-level-fluctuating zone in the Three Gorges Reservoir. The THg concentration ranged from 22.4 to 393.5 microg x kg(-1), with an average of (84.2 +/- 54.3) microg x kg(-1). 76.6% of the samples' THg content was higher than the soil background value in the Three Gorges Reservoir Region. The percentage of five mercury species (water-soluble Hg, HCl-soluble Hg, KOH-soluble Hg, H2O2-soluble Hg, residue Hg) in soils were 4.1%, 15.5%, 18.3%, 10.9%, 51.3%, respectively. The average concentrations of bioavailable mercury varied between 19.7-36.6 microg x kg(-1), and the percentage of bioavailable Hg was 22.1%-51.6% of THg. According to the geoaccumulation index, the soils were lightly polluted by Hg. Håkanson single potential ecological risk index evaluation showed that Hg species had a low potential ecological risk, moreover, soils of water-level-fluctuating zone in the Three Gorges Reservoir were at low ecological risk levels as evaluated by bioavailable Hg. While, the assessment results based on THg of soils was much higher than that based on the Hg species. Two methods of evaluation showed that the I(geo) and E(r) values calculated based on the Hg species better reflected the actual pollution levels of soils and its hazard to aquatic organisms.

Fractionation and ecological risk of metals in urban river sediments in Zhongshan City, Pearl River Delta.

PubMed

Cai, Jiannan; Cao, Yingzi; Tan, Haijian; Wang, Yanman; Luo, Jiaqi

2011-09-01

Surface sediments collected from nine urban rivers located in Zhongshan City, Pearl River Delta, were analyzed for total concentration of metals with digestion and chemical fractionation adopting the modified European Community Bureau of Reference (BCR) sequential extraction procedure. The results showed that concentration and fractionation of metals varied significantly among the rivers. The total concentration of eight metals in most rivers did not exceed the China Environmental Quality Standard for Soil, Grade III. The potential ecological risk of metals to rivers were related to the land use patterns, in the order of manufacturing areas > residential areas > agriculture areas. The concentration of Pb in the reducible fraction was relatively high (60.0-84.3%). The dominant proportions of Cd, Zn and Cu were primary in the non-residual fraction (67.0%, 71.8% and 81.4% on average respectively), while the percentages of the residual fractions of Cr and Ni varied over a wide range (43-85% and 24-71% respectively). The approaches of the Håkanson ecological risk index and Secondary Phase Enrichment Factor were applied for ecological risk assessment and metal enrichment calculation. The results indicated Hg and Cd had posed high potential ecological risk to urban rivers in this region. Meanwhile, there was widespread pollution and high enrichment of Cu in river sediments in this region. Multiple regression analysis showed that five water quality parameters (pH, DO, COD(Mn), NH(4)(+)-N, TP) had little influence on the distribution of metal fractionation. This result revealed that the ecological risk of metals was not eliminated along with the improvement in water quality. Correlation studies showed that among the metals, Group A (Cd, As, Pb, Zn Hg, r = 0.730-0.924) and Group B (Cr, Cu, Ni, r = 0.815-0.948) were obtained, and the metal contaminations were from industrial activities rather than residential.

Revisiting Darwin's hypothesis: Does greater intraspecific variability increase species' ecological breadth?

PubMed

Sides, Colby B; Enquist, Brian J; Ebersole, James J; Smith, Marielle N; Henderson, Amanda N; Sloat, Lindsey L

2014-01-01

Darwin first proposed that species with larger ecological breadth have greater phenotypic variation. We tested this hypothesis by comparing intraspecific variation in specific leaf area (SLA) to species' local elevational range and by assessing how external (abiotic) filters may influence observed differences in ecological breadth among species. Understanding the patterns of individual variation within and between populations will help evaluate differing hypotheses for structuring of communities and distribution of species. We selected 21 species with varying elevational ranges and compared the coefficient of variation of SLA for each species against its local elevational range. We examined the influence of external filters on local trait composition by determining if intraspecific changes in SLA with elevation have the same direction and similar rates of change as the change in community mean SLA value. In support of Darwin's hypothesis, we found a positive relationship between species' coefficient of variation for SLA with species' local elevational range. Intraspecific changes in SLA had the same sign, but generally lower magnitude than the community mean SLA. The results indicate that wide-ranging species are indeed characterized by greater intraspecific variation and that species' phenotypes shift along environmental gradients in the same direction as the community phenotypes. However, across species, the rate of intraspecific trait change, reflecting plastic and/or adaptive changes across populations, is limited and prevents species from adjusting to environmental gradients as quickly as interspecific changes resulting from community assembly.

Rarity and extinction risk in coral reef angelfishes on isolated islands: interrelationships among abundance, geographic range size and specialisation

NASA Astrophysics Data System (ADS)

Hobbs, Jean-Paul A.; Jones, G. P.; Munday, P. L.

2010-03-01

Determining the species most vulnerable to increasing degradation of coral reef habitats requires identification of the ecological traits that increase extinction risk. In the terrestrial environment, endemic species often face a high risk of extinction because of an association among three traits that threaten species persistence: small geographic range size, low abundance and ecological specialisation. To test whether these traits are associated in coral reef fishes, this study compared abundance and specialisation in endemic and widespread angelfishes at the remote Christmas and Cocos Islands in the Indian Ocean. The interrelationships among traits conferring high extinction risk in terrestrial communities did not apply to these fishes. Endemic angelfishes were 50-80 times more abundant than widespread species at these islands. Furthermore, there was no relationship between abundance and ecological specialisation. Endemic species were not more specialised than widespread congeners and endemics used similar resources to many widespread species. Three widespread species exhibited low abundance and some degree of specialisation, which may expose them to a greater risk of local extinction. For endemic species, high abundance and lack of specialisation on susceptible habitats may compensate for the global extinction risk posed by having extremely small geographic ranges. However, recent extinctions of small range reef fishes confirm that endemics are not immune to the increasing severity of large-scale disturbances that can affect species throughout their geographic range.

Cryptic elevational zonation in trapdoor spiders (Araneae, Antrodiaetidae, Aliatypus janus complex) from the California southern Sierra Nevada.

PubMed

Starrett, James; Hayashi, Cheryl Y; Derkarabetian, Shahan; Hedin, Marshal

2018-01-01

The relative roles of ecological niche conservatism versus niche divergence in promoting montane speciation remains an important topic in biogeography. Here, our aim was to test whether lineage diversification in a species complex of trapdoor spiders corresponds with riverine barriers or with an ecological gradient associated with elevational tiering. Aliatypus janus was sampled from throughout its range, with emphasis on populations in the southern Sierra Nevada Mountains of California. We collected multi-locus genetic data to generate a species tree for A. janus and its close relatives. Coalescent based hypothesis tests were conducted to determine if genetic breaks within A. janus conform to riverine barriers. Ecological niche models (ENM) under current and Last Glacial Maximum (LGM) conditions were generated and hypothesis tests of niche conservatism and divergence were performed. Coalescent analyses reveal deeply divergent genetic lineages within A. janus, likely corresponding to cryptic species. Two primary lineages meet along an elevational gradient on the western slopes of the southern Sierra Nevada Mountains. ENMs under both current and LGM conditions indicate that these groups occupy largely non-overlapping niches. ENM hypothesis testing rejected niche identity between the two groups, and supported a sharp ecological gradient occurring where the groups meet. However, the niche similarity test indicated that the two groups may not inhabit different background niches. The Sierra Nevada Mountains provide a natural laboratory for simultaneously testing ecological niche divergence and conservatism and their role in speciation across a diverse range of taxa. Aliatypus janus represents a species complex with cryptic lineages that may have diverged due to parapatric speciation along an ecological gradient, or been maintained by the evolution of ecological niche differences following allopatric speciation. Copyright © 2017 Elsevier Inc. All rights reserved.

75 years of dryland science: Trends and gaps in arid ecology literature

PubMed Central

Dickman, Chris R.; Wardle, Glenda M.

2017-01-01

Growth in the publication of scientific articles is occurring at an exponential rate, prompting a growing need to synthesise information in a timely manner to combat urgent environmental problems and guide future research. Here, we undertake a topic analysis of dryland literature over the last 75 years (8218 articles) to identify areas in arid ecology that are well studied and topics that are emerging. Four topics—wetlands, mammal ecology, litter decomposition and spatial modelling, were identified as ‘hot topics’ that showed higher than average growth in publications from 1940 to 2015. Five topics—remote sensing, climate, habitat and spatial, agriculture and soils-microbes, were identified as ‘cold topics’, with lower than average growth over the survey period, but higher than average numbers of publications. Topics in arid ecology clustered into seven broad groups on word-based similarity. These groups ranged from mammal ecology and population genetics, broad-scale management and ecosystem modelling, plant ecology, agriculture and ecophysiology, to populations and paleoclimate. These patterns may reflect trends in the field of ecology more broadly. We also identified two broad research gaps in arid ecology: population genetics, and habitat and spatial research. Collaborations between population genetics and ecologists and investigations of ecological processes across spatial scales would contribute profitably to the advancement of arid ecology and to ecology more broadly. PMID:28384186

Spatial-temporal distribution and potential ecological risk assessment of nonylphenol and octylphenol in riverine outlets of Pearl River Delta, China.

PubMed

Chen, Ru; Yin, Pinghe; Zhao, Ling; Yu, Qiming; Hong, Aihua; Duan, Shunshan

2014-11-01

The aquatic environments of the Pearl River Delta in Southern China are subjected to contamination with various industrial chemicals from local industries. In this paper, the occurrence, seasonal variation and spatial distribution of alkylphenol octylphenol (OP) and nonylphenol (NP) in river surface water and sediments in the runoff outlets of the Pearl River Delta were investigated. NP and OP were detected in all water and sediment samples and their mean concentrations in surface water during the dry season ranged from 810 to 3366 ng/L and 85.5 to 581 ng/L, respectively, and those in sediments ranged from 14.2 to 95.2 ng/g dw and 0.4 to 3.0 ng/g dw, respectively. In surface water, much higher concentrations were detected in the dry season than those in the wet season. In sediments, the concentrations in the dry season were also mostly higher. High concentrations of NP and OP were found in Humen outlet, likely due to high levels of domestic and industrial wastewater discharges. An ecological risk assessment with the use of hazard quotient (HQ) was also carried out and the HQ values ranged from 3.6×10(-5) to 35 and 64% of samples gave a HQ>1, indicating that the current levels of NP and OP pose a significant risk to the relevant aquatic organisms in the region. Copyright © 2014. Published by Elsevier B.V.

Dispersal, niche breadth and population extinction: colonization ratios predict range size in North American dragonflies.

PubMed

McCauley, Shannon J; Davis, Christopher J; Werner, Earl E; Robeson, Michael S

2014-07-01

Species' range sizes are shaped by fundamental differences in species' ecological and evolutionary characteristics, and understanding the mechanisms determining range size can shed light on the factors responsible for generating and structuring biological diversity. Moreover, because geographic range size is associated with a species' risk of extinction and their ability to respond to global changes in climate and land use, understanding these mechanisms has important conservation implications. Despite the hypotheses that dispersal behaviour is a strong determinant of species range areas, few data are available to directly compare the relationship between dispersal behaviour and range size. Here, we overcome this limitation by combining data from a multispecies dispersal experiment with additional species-level trait data that are commonly hypothesized to affect range size (e.g. niche breadth, local abundance and body size.). This enables us to examine the relationship between these species-level traits and range size across North America for fifteen dragonfly species. Ten models based on a priori predictions about the relationship between species traits and range size were evaluated and two models were identified as good predictors of species range size. These models indicated that only two species' level traits, dispersal behaviour and niche breadth were strongly related to range size. The evidence from these two models indicated that dragonfly species that disperse more often and further had larger North American ranges. Extinction and colonization dynamics are expected to be a key linkage between dispersal behaviour and range size in dragonflies. To evaluate how extinction and colonization dynamics among dragonflies were related to range size we used an independent data set of extinction and colonization rates for eleven dragonfly species and assessed the relationship between these populations rates and North American range areas for these species. We found a negative relationship between North American range size and species' extinction-to-colonization ratios. Our results indicate that metapopulation dynamics act to shape the extent of species' continental distributions. These population dynamics are likely to interact with dispersal behaviour, particularly at species range margins, to determine range limits and ultimately species range sizes. © 2013 The Authors. Journal of Animal Ecology © 2013 British Ecological Society.

'Inconstant males' and the maintenance of labile sex expression in subdioecious plants.

PubMed

Ehlers, Bodil K; Bataillon, Thomas

2007-01-01

* Here, we evaluate the role of pollen limitation and selfing in the maintenance of labile sex expression in subdioecious plant species. * We used a literature survey to explore which factors correlated with a significant occurrence of hermaphrodites in dioecious species. We developed models to explore the selective maintenance of labile sex expression. The models had similar ecological assumptions but differed in the genetic basis of sex lability. * We found that a significant frequency of hermaphrodites was associated with animal pollination, and that hermaphrodites were 'inconstant' males with perfect flowers, suggesting evolution through the gynodioecious pathway. Models showed that a modifier converting pure males into inconstant males could be maintained under a wide range of reduction in both male and female fitness. Pollen limitation and self-fertilization facilitated invasion of the modifier. Depending on the genetics of sex determination, we found pure dioecy, stable subdioecy (trioecy), and situations where inconstant males coexisted with either pure females or pure males. Under selfing and pollen limitation, certain conditions selected for inconstant males which will drive populations to extinction. * We discuss our results in relation to the evolution towards, and the breakdown of, dioecy, and the ecological and evolutionary implications of labile sex expression.

Depression symptoms among Mexican American youth: paternal parenting in the context of maternal parenting, economic stress, and youth gender.

PubMed

García, Jorge I Ramírez; Manongdo, Jennifer A; Ozechowski, Timothy J

2014-01-01

Mexican American youth (N = 146; age range: 14-19 years) living in an immigrant enclave who resided with both parents reported depression symptoms, paternal and maternal acceptance, paternal and maternal harsh parenting, and economic stress. Despite lower levels of youth-reported paternal parenting relative to maternal parenting, paternal acceptance was significantly related to youth depression symptoms in a path model that accounted for parenting intercorrelations as well as other significant correlates of youth depression symptoms. We found evidence suggesting that the relation between youth-reported paternal acceptance and depression might be stronger for girls than for boys. Using an ecological analytic framework, we found that: (a) the link between economic stress and youth depression was robust, and (b) only one parenting variable (paternal acceptance) may partially mediate the link between economic stress and depression symptoms. Our results suggest that paternal parenting and youth gender deserve further consideration in longitudinal research and intervention research addressing depression among Latino youth. Ecological models that highlight the influence of settings where Latino youth and families live should be considered in research on the family relationship context of youth depression.

Ecological range shift in the polyploid members of the South American genus Fosterella (Bromeliaceae).

PubMed

Paule, Juraj; Wagner, Natascha D; Weising, Kurt; Zizka, Georg

2017-08-01

The distribution of polyploidy along a relatively steep Andean elevation and climatic gradient is studied using the genus Fosterella L.B. Sm. (Bromeliaceae) as a model system. Ecological differentiation of cytotypes and the link of polyploidy with historical biogeographic processes such as dispersal events and range shift are assessed. 4',6-Diamidino-2-phenylindole (DAPI) staining of nuclei and flow cytometry were used to estimate the ploidy levels of 159 plants from 22 species sampled throughout the distribution range of the genus. Ecological differentiation among ploidy levels was tested by comparing the sets of climatic variables. Ancestral chromosome number reconstruction was carried out on the basis of a previously generated phylogeographic framework. This study represents the first assessment of intrageneric, intraspecific and partially intrapopulational cytotype diversity in a genus of the Bromeliaceae family. In Fosterella , the occurrence of polyploidy was limited to the phylogenetically isolated penduliflora and rusbyi groups. Cytotypes were found to be ecologically differentiated, showing that polyploids preferentially occupy colder habitats with high annual temperature variability (seasonality). The combined effects of biogeographic history and adaptive processes are presumed to have shaped the current cytotype distribution in the genus. The results provide indirect evidence for both adaptive ecological and non-adaptive historical processes that jointly influenced the cytotype distribution in the predominantly Andean genus Fosterella (Bromeliaceae). The results also exemplify the role of polyploidy as an important driver of speciation in a topographically highly structured and thus climatically diverse landscape. © The Author 2017. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com

[Awareness of hazards to health caused by pollution of the environment].

PubMed

Racz, A

1993-01-01

This work deals with the results of an ecological/psychological study into the development of Zagreb inhabitants awareness of the potential health risks posed by the ten most significant forms of environmental pollution and into how each examinee influences the development of ecological consciousness. This research was conducted with representative population sample of two significantly differently ecologically critical Zagreb communities: the shanty town community of Kozari Bokand the highly urbanized community of Slobostina. The survey was conducted on site using the Liekert scale in 1990. The results have shown that air and water pollution are considered potentially most dangerous, as opposed to the total lack of awareness concerning noise pollution. The factors significant in the formation of ecological awareness are: occupation and the perception of immediate danger as opposed to age, sex and personal background. However, the subject's educational level and familiarity with the relevant facts are crucial elements affecting the awakening and development of ecological consciousness.

Resilience and challenges of marine social-ecological systems under complex and interconnected drivers.

PubMed

Villasante, Sebastián; Macho, Gonzalo; Antelo, Manel; Rodríguez-González, David; Kaiser, Michel J

2013-12-01

In this paper, we summarize the contributions made by an interdisciplinary group of researchers from different disciplines (biology, ecology, economics, and law) that deal with key dimensions of marine social-ecological systems. Particularly, the local and global seafood provision; the feasibility and management of marine protected areas; the use of marine ecosystem services; the institutional dimension in European fisheries, and the affordable models for providing scientific advice to small-scale fisheries. This Special Issue presents key findings from selected case studies around the world available to educators, policy makers, and the technical community. Together, these papers show that a range of diverse ecological, economic, social, and institutional components often mutually interact at spatial and temporal scales, which evidence that managing marine social-ecological systems needs a continuous adaptability to navigate into new governance systems.

Video cameras on wild birds.

PubMed

Rutz, Christian; Bluff, Lucas A; Weir, Alex A S; Kacelnik, Alex

2007-11-02

New Caledonian crows (Corvus moneduloides) are renowned for using tools for extractive foraging, but the ecological context of this unusual behavior is largely unknown. We developed miniaturized, animal-borne video cameras to record the undisturbed behavior and foraging ecology of wild, free-ranging crows. Our video recordings enabled an estimate of the species' natural foraging efficiency and revealed that tool use, and choice of tool materials, are more diverse than previously thought. Video tracking has potential for studying the behavior and ecology of many other bird species that are shy or live in inaccessible habitats.

Transcendent Pluralism: A Middle-Range Theory of Nonviolent Social Transformation Through Human and Ecological Dignity.

PubMed

Perry, Donna J

2015-01-01

Transcendent pluralism is a middle-range theory that focuses on the emergence of human dignity within relationships among diverse peoples through nonviolent social transformation. The theory proposes that contemporary social problems that negatively influence health are rooted in human and ecological devaluation and that healing is needed through the advance of dignity. The theory has been developed through both deductive and inductive processes including 4 research studies. The theory of transcendent pluralism provides a framework for nurses seeking to advance dignity. This article provides an overview of the theory's development and components.

Introduction pathway and climate trump ecology and life history as predictors of establishment success in alien frogs and toads

PubMed Central

Rago, Alfredo; While, Geoffrey M; Uller, Tobias

2012-01-01

A major goal for ecology and evolution is to understand how abiotic and biotic factors shape patterns of biological diversity. Here, we show that variation in establishment success of nonnative frogs and toads is primarily explained by variation in introduction pathways and climatic similarity between the native range and introduction locality, with minor contributions from phylogeny, species ecology, and life history. This finding contrasts with recent evidence that particular species characteristics promote evolutionary range expansion and reduce the probability of extinction in native populations of amphibians, emphasizing how different mechanisms may shape species distributions on different temporal and spatial scales. We suggest that contemporary changes in the distribution of amphibians will be primarily determined by human-mediated extinctions and movement of species within climatic envelopes, and less by species-typical traits. PMID:22957152

Anthropogenic nitrogen deposition induces rapid ecological changes in alpine lakes of Colorado Front Range (USA)

USGS Publications Warehouse

Wolfe, A.P.; Baron, Jill S.; Cornett, R.J.

2001-01-01

Recent sediments from two alpine lakes (> 3300 m asl) in the Colorado Front Range (USA) register marked and near-synchronous changes that are believed to represent ecological responses to enhanced atmospheric deposition of fixed nitrogen from anthropogenic sources. Directional shifts in sediment proxies include greater representations of mesotrophic diatoms and increasingly depleted δ15N values. These trends are particularly pronounced since ~ 1950, and appear to chronicle lake responses to excess N derived from agricultural and industrial sources to the east. The rate and magnitude of recent ecological changes far exceed the context of natural variability, as inferred from comparative analyses of a long core capturingthe entire 14,000-year postglacial history of one of the lakes. Nitrogen deposition to these seemingly pristine natural areas has resulted in subtle but detectable limnological changes that likely represent the beginning of a stronger response to nitrogen enrichment.

Anthropogenic nitrogen deposition induces rapid ecological changes in alpine lakes of the Colorado Front Range (USA)

USGS Publications Warehouse

Wolfe, A.P.; Baron, Jill S.; Cornett, R.J.

2001-01-01

Recent sediments from two alpine lakes (> 3300 m asl) in the Colorado Front Range (USA) register marked and near-synchronous changes that are believed to represent ecological responses to enhanced atmospheric deposition of fixed nitrogen from anthropogenic sources. Directional shifts in sediment proxies include greater representations of mesotrophic diatoms and increasingly depleted ??15N values. These trends are particularly pronounced since ??? 1950, and appear to chronicle lake responses to excess N derived from agricultural and industrial sources to the east. The rate and magnitude of recent ecological changes far exceed the context of natural variability, as inferred from comparative analyses of a long core capturing the entire 14,000-year postglacial history of one of the lakes. Nitrogen deposition to these seemingly pristine natural areas has resulted in subtle but detectable limnological changes that likely represent the beginning of a stronger response to nitrogen enrichment.

Ecological and population genetics of locally rare plants: A review

Treesearch

Simon A. Lei

2001-01-01

Plant species with limited dispersal ability, narrow geographical and physiological tolerance ranges, as well as with specific habitat and ecological requirements are likely to be rare. Small and isolated populations and species contain low levels of within-population genetic variation in many plant species. The gene pool of plants is a product of phenotype-environment...

Ecological Mindfulness, Spirituality, and Life-Long (Hybrid, Dialogical) Learning: A Tribute to Michiel Van Eijck

ERIC Educational Resources Information Center

Roth, Wolff-Michael

2015-01-01

In this tribute, I articulate the contributions Michiel van Eijck made to science education, as experienced through our relation, which ranged from supervisor and colleague to friend. His ecological thinking about human knowing, which was reflected in his spiritual inclinations, constitutes his legacy that will have an impact on our field for…

Ecology and conservation of lynx in the United States

Treesearch

Leonard F. Ruggiero; Keith B. Aubry; Steven W. Buskirk; Gary M. Koehler; Charles J. Krebs; Kevin S. McKelvey; John R. Squires

1999-01-01

Once found throughout the Rocky Mountains and forests of the northern states, the lynx now hides in pockets of its former range while feeding mostly on small animals like snowshoe hares. A team of government and university scientists review the newest scientific knowledge of this unique cat's history, distribution, and ecology. The chapters on this web site...

Ecology of bottomland oaks in the southeastern United states

Treesearch

Emile S. Gardiner

2001-01-01

0aks (Querczrs spp.) are among the most ecologically and economically valued trees of the floodplain forests which occupy the river valleys that dissect the Gulf and Atlantic coastal plains of the southeastem United States. In these floodplain forests, several species from the sections Quercus and Lobarae are commonly found distributed along a gradient of sites ranging...

MillionTreesNYC, green infrastructure and urban ecology symposium March 5-6, 2010

Treesearch

Erika S. Svendsen; Jacqueline W.T. Lu

2010-01-01

On March 5-6, 2010, over two hundred researchers and practitioners came together at The New School to showcase scientific innovation in the field of urban forestry and greening. The MillionTreesNYC, Green Infrastructure and Urban Ecology Research Symposium engaged professionals from a broad range of disciplines including sociology, planning,...

Frogs, fish and forestry: An integrated watershed network paradigm conserves biodiversity and ecological services

Treesearch

Hartwell H. Welsh Jr.

2011-01-01

Successfully addressing the multitude of stresses influencing forest catchments, their native biota, and the vital ecological services they provide humanity will require adapting an integrated view that incorporates the full range of natural and anthropogenic disturbances acting on these landscapes and their embedded fluvial networks. The concepts of dendritic networks...

New data sources and derived products for the SRER digital spatial database

Treesearch

Craig Wissler; Deborah Angell

2003-01-01

The Santa Rita Experimental Range (SRER) digital database was developed to automate and preserve ecological data and increase their accessibility. The digital data holdings include a spatial database that is used to integrate ecological data in a known reference system and to support spatial analyses. Recently, the Advanced Resource Technology (ART) facility has added...

Spatial distribution of earthworms in an east Texas forest ecosystem

Treesearch

Melissa A. Bozarth; Kenneth W. Farrish; George A. Damoff; James VanKley; J. Leon Young

2016-01-01

Earthworms were collected and identified in different ecological habitats of the Stephen F. Austin Experimental Forest (SFAEF) in the Piney Woods Ecoregion (PWE) of Texas. Earthworm spatial distribution data were collected over four distinct ecological habitats with a range of soil conditions and vegetative cover. A total of 128 sampling plots were surveyed in two...

Building Ecological Complexity in the Classroom Using Pea Aphids & Components of Their Community

ERIC Educational Resources Information Center

Richardson, Matthew L.; Hari, Janice

2009-01-01

Teachers face the challenge of introducing ecological concepts in an authentic way that students can apply to their lives and surroundings. Fieldwork helps achieve this goal and can have a range of beneficial impacts on participants, but opportunities to conduct fieldwork can be limited, especially in urban environments. Urban environments are…

ASSESSING LANDSCAPE CHANGE AND ITS CONSEQUENCES TO ECOLOGICAL RESOURCES AT REGIONAL SCALES A CASE STUDY FROM THE UNITED STATES MID-ATLANTIC REGION

EPA Science Inventory

There is a growing concern about broad-scale changes in landscape features and the consequences of changes on a range of ecological goods and services, including goods and services related to human health and natural systems. The US Environmental Protection Agency has developed a...

Assessing ecological departure from reference conditions with the Fire Regime Condition Class (FRCC) Mapping Tool

Treesearch

Stephen W. Barrett; Thomas DeMeo; Jeffrey L. Jones; J.D. Zeiler; Lee C. Hutter

2006-01-01

Knowledge of ecological departure from a range of reference conditions provides a critical context for managing sustainable ecosystems. Fire Regime Condition Class (FRCC) is a qualitative measure characterizing possible departure from historical fire regimes. The FRCC Mapping Tool was developed as an ArcMap extension utilizing the protocol identified by the Interagency...

What data should we collect? A framework for identifying indicators of ecosystem contributions to human well being

EPA Science Inventory

Ecological data enable a range of policy relevant analyses; the right ecological data enable ecosystem analyses to be linked to human well being making them more relevant and useful. The challenge we address is how to identify the right data. Our approach, founded on the “final e...

Camouflage through colour change: mechanisms, adaptive value and ecological significance

PubMed Central

Flores, Augusto A. V.

2017-01-01

Animals from a wide range of taxonomic groups are capable of colour change, of which camouflage is one of the main functions. A considerable amount of past work on this subject has investigated species capable of extremely rapid colour change (in seconds). However, relatively slow colour change (over hours, days, weeks and months), as well as changes arising via developmental plasticity are probably more common than rapid changes, yet less studied. We discuss three key areas of colour change and camouflage. First, we review the mechanisms underpinning colour change and developmental plasticity for camouflage, including cellular processes, visual feedback, hormonal control and dietary factors. Second, we discuss the adaptive value of colour change for camouflage, including the use of different camouflage types. Third, we discuss the evolutionary–ecological implications of colour change for concealment, including what it can tell us about intraspecific colour diversity, morph-specific strategies, and matching to different environments and microhabitats. Throughout, we discuss key unresolved questions and present directions for future work, and highlight how colour change facilitates camouflage among habitats and arises when animals are faced with environmental changes occurring over a range of spatial and temporal scales. This article is part of the themed issue ‘Animal coloration: production, perception, function and application’. PMID:28533459

Madicolous Chironomidae from the Brazilian Atlantic Forest: a checklist with notes on altitudinal distributions (Diptera, Insecta)

PubMed Central

Shimabukuro, Erika Mayumi; Trivinho-Strixino, Susana

2018-01-01

Abstract Thin layers of water running over rocky surfaces are characteristic of madicolous habitats, which harbor a peculiar Chironomidae community. However, information on the identity, distribution, and ecology of madicolous chironomids in the Neotropical region are still sparse. The main purpose of this research is to reveal and contribute to the ecology of madicolous Chironomidae species, especially regarding their altitudinal distribution in the Atlantic Forest. Sampling was performed using our own designed emergence traps deployed from 0 to 2700 m a.s.l. in 70 sites in three mountains in southeastern Brazil. Sixty taxa of chironomids were collected and identified, of which only 22 are known to science. Most of the species showed a wider distribution than previously known, both in terms of geographic and altitudinal ranges, while others showed significant association with particular altitudinal bands (as evidenced by the indicator species analysis). Atlantic Forest mountainous regions are known to harbor one of the richest fauna in the world and have been suffering from several types of environmental impacts, including climate change, which will especially affect taxa living in specialized habitats. The narrow range of tolerance to environmental conditions verified for mountain species, and the fact that many of them are rare and endemic, make the conservation efforts in these areas indispensable. PMID:29706784

Comparative analyses of animal-tracking data reveal ecological significance of endothermy in fishes

PubMed Central

Watanabe, Yuuki Y.; Goldman, Kenneth J.; Caselle, Jennifer E.; Chapman, Demian D.; Papastamatiou, Yannis P.

2015-01-01

Despite long evolutionary separations, several sharks and tunas share the ability to maintain slow-twitch, aerobic red muscle (RM) warmer than ambient water. Proximate causes of RM endothermy are well understood, but ultimate causes are unclear. Two advantages often proposed are thermal niche expansion and elevated cruising speeds. The thermal niche hypothesis is generally supported, because fishes with RM endothermy often exhibit greater tolerance to broad temperature ranges. In contrast, whether fishes with RM endothermy cruise faster, and achieve any ecological benefits from doing so, remains unclear. Here, we compiled data recorded by modern animal-tracking tools for a variety of free-swimming marine vertebrates. Using phylogenetically informed allometry, we show that both cruising speeds and maximum annual migration ranges of fishes with RM endothermy are 2–3 times greater than fishes without it, and comparable to nonfish endotherms (i.e., penguins and marine mammals). The estimated cost of transport of fishes with RM endothermy is twice that of fishes without it. We suggest that the high energetic cost of RM endothermy in fishes is offset by the benefit of elevated cruising speeds, which not only increase prey encounter rates, but also enable larger-scale annual migrations and potentially greater access to seasonally available resources. PMID:25902489

Recent advances in our knowledge of Australian anisakid nematodes

PubMed Central

Shamsi, Shokoofeh

2014-01-01

Anisakidosis is an emerging infection associated with a wide range of clinical syndromes in humans caused by members of the family Anisakidae. Anisakid nematodes have a cosmopolitan distribution and infect a wide range of invertebrates and vertebrates during their life cycles. Since the first report of these parasites in humans during the early 60s, anisakid nematodes have attracted considerable attention as emerging zoonotic parasites. Along with rapid development of various molecular techniques during last several decades, this has caused a significant change in the taxonomy and systematics of these parasites. However, there are still huge gaps in our knowledge on various aspects of the biology and ecology of anisakid nematodes in Australia. Although the use of advanced morphological and molecular techniques to study anisakids had a late start in Australia, great biodiversity was found and unique species were discovered. Here an updated list of members within the family and the current state of knowledge on Australian anisakids will be provided. Given that the employment of advanced techniques to study these important emerging zoonotic parasites in Australia is recent, further research is needed to understand the ecology and biology of these socio economically important parasites. After a recent human case of anisakidosis in Australia, such understanding is crucial if control and preventive strategies are to be established in this country. PMID:25180162

Camouflage through colour change: mechanisms, adaptive value and ecological significance.

PubMed

Duarte, Rafael C; Flores, Augusto A V; Stevens, Martin

2017-07-05

Animals from a wide range of taxonomic groups are capable of colour change, of which camouflage is one of the main functions. A considerable amount of past work on this subject has investigated species capable of extremely rapid colour change (in seconds). However, relatively slow colour change (over hours, days, weeks and months), as well as changes arising via developmental plasticity are probably more common than rapid changes, yet less studied. We discuss three key areas of colour change and camouflage. First, we review the mechanisms underpinning colour change and developmental plasticity for camouflage, including cellular processes, visual feedback, hormonal control and dietary factors. Second, we discuss the adaptive value of colour change for camouflage, including the use of different camouflage types. Third, we discuss the evolutionary-ecological implications of colour change for concealment, including what it can tell us about intraspecific colour diversity, morph-specific strategies, and matching to different environments and microhabitats. Throughout, we discuss key unresolved questions and present directions for future work, and highlight how colour change facilitates camouflage among habitats and arises when animals are faced with environmental changes occurring over a range of spatial and temporal scales.This article is part of the themed issue 'Animal coloration: production, perception, function and application'. © 2017 The Authors.

Ecological regime shifts and changes of lake ecosystem service in a shallow Yangtze lake (Taibai Lake, China) over the past 150 years

NASA Astrophysics Data System (ADS)

Dong, X.; Xu, M.; Yang, X.

2017-12-01

Shallow lakes provide a range of ecosystem services such as water supply, biodiversity, aquaculture, tourism, shipping and flood regulation. Over recent decades, many lakes have become severely deteriorated due to a coupled natural and human disturbance. Given the limited monitoring records, however, we still have little knowledge on how, when and why those lake experienced ecological status shifts, and how the lake ecosystem service changed. Paleolimnological techniques were widely used in understanding the historical environmental and ecological changes. Here, we chose a typical eutrophic shallow lake, Taibai Lake, and acquired geochemistry proxies, grain size, diatom, cladocera and chironomid from a 210Pb and 137Cs dated sediment core. Document records and monitoring data are also included as important marks of social and environmental change. A T-test based algorithm of STARS reveal at least two ecological shifts, respectively in the 1960s and the 1990s. The sudden shift in the 1960s is supposed to be influenced by a dam and sluice construction in the 1950s and another shift in the 1990s should be a critical transition due to the alternation of ecosystem structure for higher fishery production. Correspondingly, lake ecosystem service (LES) also experienced significant changes. Prior to 1930s, different types of LES kept relatively stable with low values. With the dam construction in the 1960s, the changed hydrological condition led to gradual increases in both regulation and provision service. However, with much effort on fishery and reclamation, the regulation service of the lake decreased, exhibiting a tradeoff among LES. After 1990s, with intense aquaculture, most types of LSE suffered a further decrease. The long-term records exhibited that ecosystem services in primary productivity and biodiversity maintenance increased (synergies) whereas services in water-purification and climate regulating decreased significantly (tradeoffs) since 1950s, when local people are seeking higher desired services by human "modification" on lake ecosystem. By long-term records, temporal perspectives on such dynamic tradeoffs and synergies relationship among various ESs under the context of different types resource utilization over time have significant implications for management initiatives.

Coupled range dynamics of brood parasites and their hosts responding to climate and vegetation changes.

PubMed

Péron, Guillaume; Altwegg, Res; Jamie, Gabriel A; Spottiswoode, Claire N

2016-09-01

As populations shift their ranges in response to global change, local species assemblages can change, setting the stage for new ecological interactions, community equilibria and evolutionary responses. Here, we focus on the range dynamics of four avian brood parasite species and their hosts in southern Africa, in a context of bush encroachment (increase in woody vegetation density in places previously occupied by savanna-grassland mosaics) favouring some species at the expense of others. We first tested whether hosts and parasites constrained each other's ability to expand or maintain their ranges. Secondly, we investigated whether range shifts represented an opportunity for new host-parasite and parasite-parasite interactions. We used multispecies dynamic occupancy models with interactions, fitted to citizen science data, to estimate the contribution of interspecific interactions to range shifts and to quantify the change in species co-occurrence probability over a 25-year period. Parasites were able to track their hosts' range shifts. We detected no deleterious effect of the parasites' presence on either the local population viability of host species or the hosts' ability to colonize newly suitable areas. In the recently diversified indigobird radiation (Vidua spp.), following bush encroachment, the new assemblages presented more potential opportunities for speciation via host switch, but also more potential for hybridization between extant lineages, also via host switch. Multispecies dynamic occupancy models with interactions brought new insights into the feedbacks between range shifts, biotic interactions and local demography: brood parasitism had little detected impact on extinction or colonization processes, but inversely the latter processes affected biotic interactions via the modification of co-occurrence patterns. © 2016 The Authors. Journal of Animal Ecology © 2016 British Ecological Society.

Colour spaces in ecology and evolutionary biology.

PubMed

Renoult, Julien P; Kelber, Almut; Schaefer, H Martin

2017-02-01

The recognition that animals sense the world in a different way than we do has unlocked important lines of research in ecology and evolutionary biology. In practice, the subjective study of natural stimuli has been permitted by perceptual spaces, which are graphical models of how stimuli are perceived by a given animal. Because colour vision is arguably the best-known sensory modality in most animals, a diversity of colour spaces are now available to visual ecologists, ranging from generalist and basic models allowing rough but robust predictions on colour perception, to species-specific, more complex models giving accurate but context-dependent predictions. Selecting among these models is most often influenced by historical contingencies that have associated models to specific questions and organisms; however, these associations are not always optimal. The aim of this review is to provide visual ecologists with a critical perspective on how models of colour space are built, how well they perform and where their main limitations are with regard to their most frequent uses in ecology and evolutionary biology. We propose a classification of models based on their complexity, defined as whether and how they model the mechanisms of chromatic adaptation and receptor opponency, the nonlinear association between the stimulus and its perception, and whether or not models have been fitted to experimental data. Then, we review the effect of modelling these mechanisms on predictions of colour detection and discrimination, colour conspicuousness, colour diversity and diversification, and for comparing the perception of colour traits between distinct perceivers. While a few rules emerge (e.g. opponent log-linear models should be preferred when analysing very distinct colours), in general model parameters still have poorly known effects. Colour spaces have nonetheless permitted significant advances in ecology and evolutionary biology, and more progress is expected if ecologists compare results between models and perform behavioural experiments more routinely. Such an approach would further contribute to a better understanding of colour vision and its links to the behavioural ecology of animals. While visual ecology is essentially a transfer of knowledge from visual sciences to evolutionary ecology, we hope that the discipline will benefit both fields more evenly in the future. © 2015 Cambridge Philosophical Society.

Application synergies between the NASA Pre- Aerosol Cloud and ocean Ecosystem (PACE) and Hyperspectral Infrared Imager (HyspIRI) missions

NASA Astrophysics Data System (ADS)

Lee, C. M.; Omar, A. H.; Hook, S. J.; Tzortziou, M.; Luvall, J. C.; Turner, W. W.

2016-02-01

Observations from the Pre-Aerosol Cloud and ocean Ecosystem (PACE) and Hyperspectral InfraRed Imager (HyspIRI) satellite missions are highly complementary and have the potential to significantly advance understanding of various science and applications challenges in the ocean sciences and water quality communities. Scheduled for launch in the 2022 timeframe, PACE is designed to make climate-quality global measurements essential for understanding ocean biology, biogeochemistry and ecology, and determining the role of the ocean in global biogeochemical cycling and ocean ecology, and how it affects and is affected by climate change. PACE will provide high signal-to-noise, hyperspectral observations over an extended spectral range (UV to SWIR) and will have global coverage every 1-2 days, at approximately 1 km spatial resolution; furthermore, PACE is currently designed to include a polarimeter, which will vastly improve atmospheric correction algorithms over water bodies. The PACE mission will enable advances in applications across a range of areas, including oceans, climate, water resources, ecological forecasting, disasters, human health and air quality. HyspIRI, with contiguous measurements in VSWIR, and multispectral measurements in TIR, will be able to provide detailed spectral observations and higher spatial resolution (30 to 60-m) over aquatic systems, but at a temporal resolution that is approximately 5-16 days. HyspIRI would enable improved, detailed studies of aquatic ecosystems, including benthic communities, algal blooms, coral reefs, and wetland species distribution as well as studies of water quality indicators or pollutants such as oil spills, suspended sediment, and colored dissolved organic matter. Together, PACE and HyspIRI will be able to address numerous applications and science priorities, including improving and extending climate data records, and studies of inland, coastal and ocean environments.

Decomposition of complex microbial behaviors into resource-based stress responses

PubMed Central

Carlson, Ross P.

2009-01-01

Motivation: Highly redundant metabolic networks and experimental data from cultures likely adapting simultaneously to multiple stresses can complicate the analysis of cellular behaviors. It is proposed that the explicit consideration of these factors is critical to understanding the competitive basis of microbial strategies. Results: Wide ranging, seemingly unrelated Escherichia coli physiological fluxes can be simply and accurately described as linear combinations of a few ecologically relevant stress adaptations. These strategies were identified by decomposing the central metabolism of E.coli into elementary modes (mathematically defined biochemical pathways) and assessing the resource investment cost–benefit properties for each pathway. The approach capitalizes on the inherent tradeoffs related to investing finite resources like nitrogen into different pathway enzymes when the pathways have varying metabolic efficiencies. The subset of ecologically competitive pathways represented 0.02% of the total permissible pathways. The biological relevance of the assembled strategies was tested against 10 000 randomly constructed pathway subsets. None of the randomly assembled collections were able to describe all of the considered experimental data as accurately as the cost-based subset. The results suggest these metabolic strategies are biologically significant. The current descriptions were compared with linear programming (LP)-based flux descriptions using the Euclidean distance metric. The current study's pathway subset described the experimental fluxes with better accuracy than the LP results without having to test multiple objective functions or constraints and while providing additional ecological insight into microbial behavior. The assembled pathways seem to represent a generalized set of strategies that can describe a wide range of microbial responses and hint at evolutionary processes where a handful of successful metabolic strategies are utilized simultaneously in different combinations to adapt to diverse conditions. Contact: rossc@biofilms.montana.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:19008248

Environmental management: Integrating ecological evaluation, remediation, restoration, natural resource damage assessment and long-term stewardship on contaminated lands

PubMed Central

Burger, Joanna

2014-01-01

Ecological evaluation is essential for remediation, restoration, and Natural Resource Damage Assessment (NRDA), and forms the basis for many management practices. These include determining status and trends of biological, physical, or chemical/radiological conditions, conducting environmental impact assessments, performing remedial actions should remediation fail, managing ecosystems and wildlife, and assessing the efficacy of remediation, restoration, and long-term stewardship. The objective of this paper is to explore the meanings of these assessments, examine the relationships among them, and suggest methods of integration that will move environmental management forward. While remediation, restoration, and NRDA, among others, are often conducted separately, it is important to integrate them for contaminated land where the risks to ecoreceptors (including humans) can be high, and the potential damage to functioning ecosystems great. Ecological evaluations can range from inventories of local plants and animals, determinations of reproductive success of particular species, levels of contaminants in organisms, kinds and levels of effects, and environmental impact assessments, to very formal ecological risk assessments for a chemical or other stressor. Such evaluations can range from the individual species to populations, communities, ecosystems or the landscape scale. Ecological evaluations serve as the basis for making decisions about the levels and kinds of remediation, the levels and kinds of restoration possible, and the degree and kinds of natural resource injuries that have occurred because of contamination. Many different disciplines are involved in ecological evaluation, including biologists, conservationists, foresters, restoration ecologists, ecological engineers, economists, hydrologist, and geologists. Since ecological evaluation forms the basis for so many different types of environmental management, it seems reasonable to integrate management options to achieve economies of time, energy, and costs. Integration and iteration among these disciplines is possible only with continued interactions among practitioners, regulators, policy-makers, Native American Tribes, and the general public. PMID:18687455

[Temporal and spatial characteristics of ecological risk in Shunyi, Beijing, China based on landscape structure.

PubMed

Qing, Feng Ting; Peng, Yu

2016-05-01

Based on the remote sensing data in 1997, 2001, 2005, 2009 and 2013, this article classified the landscape types of Shunyi, and the ecological risk index was built based on landscape disturbance index and landscape fragility. The spatial auto-correlation and geostatistical analysis by GS + and ArcGIS was used to study temporal and spatial changes of ecological risk. The results showed that eco-risk degree in the study region had positive spatial correlation which decreased with the increasing grain size. Within a certain grain range (<12 km), the spatial auto-correlation had an obvious dependence on scale. The random variation of spatial heterogeneity was less than spatial auto-correlation variation from 1997 to 2013, which meant the auto-correlation had a dominant role in spatial heterogeneity. The ecological risk of Shunyi was mainly at moderate level during the study period. The area of the district with higher and lower ecological risk increased, while that of mode-rate ecological risk decreased. The area with low ecological risk was mainly located in the airport region and forest of southeast Shunyi, while that with high ecological risk was mainly concentrated in the water landscape, such as the banks of Chaobai River.

Modelling ecological flow regime: an example from the Tennessee and Cumberland River basins

USGS Publications Warehouse

Knight, Rodney R.; Gain, W. Scott; Wolfe, William J.

2012-01-01

Predictive equations were developed for 19 ecologically relevant streamflow characteristics within five major groups of flow variables (magnitude, ratio, frequency, variability, and date) for use in the Tennessee and Cumberland River basins using stepbackward regression. Basin characteristics explain 50% or more of the variation for 12 of the 19 equations. Independent variables identified through stepbackward regression were statistically significant in 78 of 304 cases (α > 0.0001) and represent four major groups: climate, physical landscape features, regional indicators, and land use. Of these groups, the regional and climate variables were the most influential for determining hydrologic response. Daily temperature range, geologic factor, and rock depth were major factors explaining the variability in 17, 15, and 13 equations, respectively. The equations and independent datasets were used to explore the broad relation between basin properties and streamflow and the implication of streamflow to the study of ecological flow requirements. Key results include a high degree of hydrologic variability among least disturbed Blue Ridge streams, similar hydrologic behaviour for watersheds with widely varying degrees of forest cover, and distinct hydrologic profiles for streams in different geographic regions. Published in 2011. This article is a US Government work and is in the public domain in the USA.

What is the optimum sample size for the study of peatland testate amoeba assemblages?

PubMed

Mazei, Yuri A; Tsyganov, Andrey N; Esaulov, Anton S; Tychkov, Alexander Yu; Payne, Richard J

2017-10-01

Testate amoebae are widely used in ecological and palaeoecological studies of peatlands, particularly as indicators of surface wetness. To ensure data are robust and comparable it is important to consider methodological factors which may affect results. One significant question which has not been directly addressed in previous studies is how sample size (expressed here as number of Sphagnum stems) affects data quality. In three contrasting locations in a Russian peatland we extracted samples of differing size, analysed testate amoebae and calculated a number of widely-used indices: species richness, Simpson diversity, compositional dissimilarity from the largest sample and transfer function predictions of water table depth. We found that there was a trend for larger samples to contain more species across the range of commonly-used sample sizes in ecological studies. Smaller samples sometimes failed to produce counts of testate amoebae often considered minimally adequate. It seems likely that analyses based on samples of different sizes may not produce consistent data. Decisions about sample size need to reflect trade-offs between logistics, data quality, spatial resolution and the disturbance involved in sample extraction. For most common ecological applications we suggest that samples of more than eight Sphagnum stems are likely to be desirable. Copyright © 2017 Elsevier GmbH. All rights reserved.

Invasive plants and their ecological strategies: Prediction and explanation of woody plant invasion in New England

USGS Publications Warehouse

Herron, P.M.; Martine, C.T.; Latimer, A.M.; Leicht-Young, S. A.

2007-01-01

Effective management of introduced species requires the early identification of species that pose a significant threat of becoming invasive. To better understand the invasive ecology of species in New England, USA, we compiled a character data set with which to compare non-native species that are known invaders to non-native species that are not currently known to be invasive. In contrast to previous biological trait-based models, we employed a Bayesian hierarchical analysis to identify sets of plant traits associated with invasiveness for each of three growth forms (vines, shrubs, and trees). The resulting models identify a suite of 'invasive traits' highlighting the ecology associated with invasiveness for each of three growth forms. The most effective predictors of invasiveness that emerged from our model were 'invasive elsewhere', 'fast growth rate', 'native latitudinal range', and 'growth form'. The contrast among growth forms was pronounced. For example, 'wind dispersal' was positively correlated with invasiveness in trees, but negatively correlated in shrubs and vines. The predictive model was able to correctly classify invasive plants 67% of the time (22/33), and non-invasive plants 95% of the time (204/215). A number of potential future invasive species in New England that deserve management consideration were identified. ?? 2007 The Authors.

Psychobiological responses to critically evaluated multitasking.

PubMed

Wetherell, Mark A; Craw, Olivia; Smith, Kenny; Smith, Michael A

2017-12-01

In order to understand psychobiological responses to stress it is necessary to observe how people react to controlled stressors. A range of stressors exist for this purpose; however, laboratory stressors that are representative of real life situations provide more ecologically valid opportunities for assessing stress responding. The current study assessed psychobiological responses to an ecologically valid laboratory stressor involving multitasking and critical evaluation. The stressor elicited significant increases in psychological and cardiovascular stress reactivity; however, no cortisol reactivity was observed. Other socially evaluative laboratory stressors that lead to cortisol reactivity typically require a participant to perform tasks that involve verbal responses, whilst standing in front of evaluative others. The current protocol contained critical evaluation of cognitive performance; however, this was delivered from behind a seated participant. The salience of social evaluation may therefore be related to the response format of the task and the method of evaluation. That is, the current protocol did not involve the additional vulnerability associated with in person, face-to-face contact, and verbal delivery. Critical evaluation of multitasking provides an ecologically valid technique for inducing laboratory stress and provides an alternative tool for assessing psychological and cardiovascular reactivity. Future studies could additionally use this paradigm to investigate those components of social evaluation necessary for eliciting a cortisol response.

Coarse-resolution Ecology of Etiological Agent, Vector, and Reservoirs of Zoonotic Cutaneous Leishmaniasis in Libya.

PubMed

Samy, Abdallah M; Annajar, Badereddin B; Dokhan, Mostafa Ramadhan; Boussaa, Samia; Peterson, A Townsend

2016-02-01

Cutaneous leishmaniasis ranks among the tropical diseases least known and most neglected in Libya. World Health Organization reports recognized associations of Phlebotomus papatasi, Psammomys obesus, and Meriones spp., with transmission of zoonotic cutaneous leishmaniasis (ZCL; caused by Leishmania major) across Libya. Here, we map risk of ZCL infection based on occurrence records of L. major, P. papatasi, and four potential animal reservoirs (Meriones libycus, Meriones shawi, Psammomys obesus, and Gerbillus gerbillus). Ecological niche models identified limited risk areas for ZCL across the northern coast of the country; most species associated with ZCL transmission were confined to this same region, but some had ranges extending to central Libya. All ENM predictions were significant based on partial ROC tests. As a further evaluation of L. major ENM predictions, we compared predictions with 98 additional independent records provided by the Libyan National Centre for Disease Control (NCDC); all of these records fell inside the belt predicted as suitable for ZCL. We tested ecological niche similarity among vector, parasite, and reservoir species and could not reject any null hypotheses of niche similarity. Finally, we tested among possible combinations of vector and reservoir that could predict all recent human ZCL cases reported by NCDC; only three combinations could anticipate the distribution of human cases across the country.

Coarse-resolution Ecology of Etiological Agent, Vector, and Reservoirs of Zoonotic Cutaneous Leishmaniasis in Libya

PubMed Central

Samy, Abdallah M.; Annajar, Badereddin B.; Dokhan, Mostafa Ramadhan; Boussaa, Samia; Peterson, A. Townsend

2016-01-01

Abstract Cutaneous leishmaniasis ranks among the tropical diseases least known and most neglected in Libya. World Health Organization reports recognized associations of Phlebotomus papatasi, Psammomys obesus, and Meriones spp., with transmission of zoonotic cutaneous leishmaniasis (ZCL; caused by Leishmania major) across Libya. Here, we map risk of ZCL infection based on occurrence records of L. major, P. papatasi, and four potential animal reservoirs (Meriones libycus, Meriones shawi, Psammomys obesus, and Gerbillus gerbillus). Ecological niche models identified limited risk areas for ZCL across the northern coast of the country; most species associated with ZCL transmission were confined to this same region, but some had ranges extending to central Libya. All ENM predictions were significant based on partial ROC tests. As a further evaluation of L. major ENM predictions, we compared predictions with 98 additional independent records provided by the Libyan National Centre for Disease Control (NCDC); all of these records fell inside the belt predicted as suitable for ZCL. We tested ecological niche similarity among vector, parasite, and reservoir species and could not reject any null hypotheses of niche similarity. Finally, we tested among possible combinations of vector and reservoir that could predict all recent human ZCL cases reported by NCDC; only three combinations could anticipate the distribution of human cases across the country. PMID:26863317

A non-extensive thermodynamic theory of ecological systems

NASA Astrophysics Data System (ADS)

Van Xuan, Le; Khac Ngoc, Nguyen; Lan, Nguyen Tri; Viet, Nguyen Ai

2017-06-01

After almost 30 years of development, it is not controversial issue that the so-called Tsallis entropy provides a useful approach to studying the complexity where the non-additivity of the systems under consideration is frequently met. Also, in the ecological research, Tsallis entropy, or in other words, q-entropy has been found itself as a generalized approach to define a range of diversity indices including Shannon-Wiener and Simpson indices. As a further stage of development in theoretical research, a thermodynamic theory based on Tsallis entropy or diversity indices in ecology has to be constructed for ecological systems to provide knowledge of ecological macroscopic behaviors. The standard method of theoretical physics is used in the manipulation and the equivalence between phenomenological thermodynamics and ecological aspects is the purpose of the ongoing research. The present work is in the line of the authors research to implement Tsallis non-extensivity approach to obtain the most important thermodynamic quantities of ecological systems such as internal energy Uq and temperature Tq based on a given modeled truncated Boltzmann distribution of the Whittaker plot for a dataset. These quantities have their own ecological meaning, especially the temperature Tq provides the insight of equilibrium condition among ecological systems as it is well-known in 0th law of thermodynamics.

Distribution and ecological risk assessment of organic and inorganic pollutants in the sediments of the transnational Begej canal (Serbia-Romania).

PubMed

Dubovina, Miloš; Krčmar, Dejan; Grba, Nenad; Watson, Malcolm A; Rađenović, Dunja; Tomašević-Pilipović, Dragana; Dalmacija, Božo

2018-05-01

This research is designed to determine the level and types of pollution in the highly contaminated sediments of the international Begej canal in Timiş district, Romania and north-eastern Serbia. The cross-border canal stretch investigated is currently not navigable, but represents an important waterway between the Danube River in Serbia and the city of Timisoara. Surface sediments were monitored annually from 2008 to 2016 at 36 representative sampling locations, with a wide range of analyses, including eight heavy metals of long-term monitoring concern (Ni, Zn, Cd, Cr, Cu, Pb, As and Hg) and the 16 USEPA PAHs. The purpose of this study was to determine the diversity and impact of anthropogenic and natural sources of pollution at the pollution hot spots on the canal: at the Itebej lock (near the border with Romania) and downstream at the Klek lock. Sediment quality and ecological risk were assessed in order to determine pollutants of concern. Several multi-proxies were applied (e.g. geo-accumulation index (I geo ), ecological risk index (RI) and total benzo[a]pyrene equivalent (B[a]P eq )). To determine and predict trends, multivariate statistical methods (factor analysis of principal component analysis (PCA/FA)) were carried out on the organic and inorganic parameters analysed. In the near-border region, acute and significant ecological impacts were observed. The heavy metals Hg, Cr, Pb, Cu and Zn, and the carcinogenic PAH dibenzo[a,h]anthracene, were historically the most frequently detected harmful substances to biota in this and the wider Pannonia region. This is the first long-term study to quantify and derivate the most frequently detected harmful substances of concern for this and similar sites in the wider region, and is additionally supported by significant national and similar environmental data from previous studies in the region. Copyright © 2018 Elsevier Ltd. All rights reserved.

Terrain-based Predictive Modeling of a Functional Riparian Corridor in a Coastal Northern California Watershed

NASA Astrophysics Data System (ADS)

Robinson, T.; Davis, J. D.

2016-12-01

Riparian corridors and their associated geomorphic landforms (e.g., channels, floodplains, and terraces) and vegetation communities (e.g., forests and wetlands) have been significantly degraded in California, prompting an expansion of efforts to delineate riparian corridors and identify priorities for conservation via deed restrictions and easements. Current techniques to delineate riparian corridors for these purposes include fixed-width buffers based on stream centerlines and digitization of woody vegetation from aerial photos. Although efficient, these delineation methods do not accurately capture the extent of ecologically functional riparian corridors and result in riparian habitat being excluded from conservation efforts while non-riparian is included. From a physical perspective, ecologically functional riparian corridors have widths that vary with topography and ample space for dynamic fluvial geomorphic processes that create and maintain river morphology and vegetation and sustain ecological interactions that extend from the stream channel laterally into upland ecosystems and up- and downstream ecosystems in longitudinal directions. New terrain-based spatial analysis techniques and high-resolution digital terrain data show promise in delineating ecologically functional riparian corridors. In this study, we compare the efficacy of three terrain-based predictors of riparian corridors that have emerged in the literature—elevation above channel, flow accumulation, and distance from channel. The results of each terrain predictor are compared with field-based indicators of the riparian corridor of an alluvial reach of Mark West Creek in Sonoma County, California (a mediterranean climate). Indicators include soil type, fluvial geomorphic landforms, and vegetation. A one-meter digital terrain model from LiDAR (Light Detection and Ranging) supplied by a NASA ROSES grant is used as the base terrain data for spatial analysis. We discuss in detail the use of regional curves of hydraulic geometry in the calculation of the elevation above channel predictor because it offers the advantage of efficiency while carrying significant potential for error.

Phylogeographic reconstruction of African yellow fever virus isolates indicates recent simultaneous dispersal into east and west Africa.

PubMed

Beck, Andrew; Guzman, Hilda; Li, Li; Ellis, Brett; Tesh, Robert B; Barrett, Alan D T

2013-01-01

Yellow fever virus (YFV) is a mosquito-borne flavivirus that is a major public health problem in tropical areas of Africa and South America. There have been detailed studies on YFV ecology in West Africa and South America, but current understanding of YFV circulation on the African continent is incomplete. This inadequacy is especially notable for East and Central Africa, for which the unpredictability of human outbreaks is compounded by limitations in both historical and present surveillance efforts. Sparse availability of nucleotide sequence data makes it difficult to investigate the dispersal of YFV in these regions of the continent. To remedy this, we constructed Bayesian phylogenetic and geographic analyses utilizing 49 partial genomic sequences to infer the structure of YFV divergence across the known range of the virus on the African continent. Relaxed clock analysis demonstrated evidence for simultaneous divergence of YFV into east and west lineages, a finding that differs from previous hypotheses of YFV dispersal from reservoirs located on edges of the endemic range. Using discrete and continuous geographic diffusion models, we provide detailed structure of YFV lineage diversity. Significant transition links between extant East and West African lineages are presented, implying connection between areas of known sylvatic cycling. The results of demographic modeling reinforce the existence of a stably maintained population of YFV with spillover events into human populations occurring periodically. Geographically distinct foci of circulation are reconstructed, which have significant implications for studies of YFV ecology and emergence of human disease. We propose further incorporation of Bayesian phylogeography into formal GIS analyses to augment studies of arboviral disease.

Watershed Health: The Need for a New Perspective

NASA Astrophysics Data System (ADS)

Reeves, G.

2017-12-01

Watershed health is a measure of the condition of the aquatic ecosystem within a watershed and is indicated by a specific set of environmental conditions that provide desired ecological, social, and legal amenities. A watershed is deemed "healthy" if it has these attributes and the traditional management approach to maintaining or developing a healthy watershed is to create and maintain these specific conditions within the watershed. However, this approach may not be applicable to situations in which processes are complex, non-linear, and poorly understood. The focus on a specific set of conditions comes at the expense of recognizing the ecological processes that create and maintain habitats for an aquatic organisms and the ecological context in which they evolved, and may lead to further degradation or compromising of the ecosystems and landscapes of interest. An emerging perspective suggests that aquatic-riparian ecosystems possess a range of processes and attributes that are inherently complex, nonlinear, and dynamic and because of the variation in the size and asynchronous nature of disturbance events, conditions will vary over time among watersheds, resulting in a mosaic of biophysical conditions across the landscape. Thus, watershed health may not be a single condition but rather a suite of conditions similar to how terrestrial ecosystems are viewed, requiring an integrated assessment of a range of ecological conditions and consideration of the intactness of key ecological processes.

Techno-ecological synergy: a framework for sustainable engineering.

PubMed

Bakshi, Bhavik R; Ziv, Guy; Lepech, Michael D

2015-02-03

Even though the importance of ecosystems in sustaining all human activities is well-known, methods for sustainable engineering fail to fully account for this role of nature. Most methods account for the demand for ecosystem services, but almost none account for the supply. Incomplete accounting of the very foundation of human well-being can result in perverse outcomes from decisions meant to enhance sustainability and lost opportunities for benefiting from the ability of nature to satisfy human needs in an economically and environmentally superior manner. This paper develops a framework for understanding and designing synergies between technological and ecological systems to encourage greater harmony between human activities and nature. This framework considers technological systems ranging from individual processes to supply chains and life cycles, along with corresponding ecological systems at multiple spatial scales ranging from local to global. The demand for specific ecosystem services is determined from information about emissions and resource use, while the supply is obtained from information about the capacity of relevant ecosystems. Metrics calculate the sustainability of individual ecosystem services at multiple spatial scales and help define necessary but not sufficient conditions for local and global sustainability. Efforts to reduce ecological overshoot encourage enhancement of life cycle efficiency, development of industrial symbiosis, innovative designs and policies, and ecological restoration, thus combining the best features of many existing methods. Opportunities for theoretical and applied research to make this framework practical are also discussed.

Health risk assessment of semi-volatile organic pollutants in Lhasa River China.

PubMed

Liu, Feng; Liu, Yan; Jiang, Dongsheng; Zhang, Rongfei; Cui, Yibin; Li, Mei

2014-05-01

The semi-volatile organic compounds in Lhasa River were determined qualitatively and quantitatively by gas chromatography method with mass spectrometric detection. Total concentrations of 23 organic pollutants in samples from five sites ranged from 1.56 to 2.78 μg/L. The average concentrations for ΣPAEs, ΣPAHs and ΣBTEXs obtained in this study were 1.53, 0.33 and 0.51 μg/L, respectively. Moreover, the results of analysis of variable showed that there were significant differences (P < 0.05) among the sites for levels of ΣPAHs, ΣPAEs and ΣBTEXs. Cluster analysis was applied to detect spatial similarity for grouping of sites under the monitoring network. The results indicated that the five sites in this study could be divided into two significant groups, i.e. low and high pollutant groups. Health risk assessment was conducted by multimedia environmental goals (MEG), risk quotient (RQ) for each pollutant and hazard quotient (HQ) approach from USA ecological risk assessment (ERA) for screening stage. Calculated both total ambient severity and RQ were less than 1 and therefore minimal risk to human and ecological health. For analysis results of HQ, whether for the ingestion exposure or dermal adsorption pathway were all less than 1, the results also agreed with the RQ model and MEG model for evaluating the potential for adverse health effects due to exposure semi-volatile organic compounds from surface water. Therefore, SVOCs in Lhasa River posed little or no threat to the health of local consumers and ecological environment.

An analysis of monthly home range size in the critically endangered California Condor Gymnogyps californianus

USGS Publications Warehouse

Rivers, James W.; Johnson, Matthew J.; Haig, Susan M.; Schwarz, Carl J.; Burnett, Joseph; Brandt, Joseph; George, Daniel; Grantham, Jesse

2014-01-01

Condors and vultures comprise the only group of terrestrial vertebrates in the world that are obligate scavengers, and these species move widely to locate ephemeral, unpredictable, and patchily-distributed food resources. In this study, we used high-resolution GPS location data to quantify monthly home range size of the critically endangered California Condor Gymnogyps californianus throughout the annual cycle in California. We assessed whether individual-level characteristics (age, sex and breeding status) and factors related to endangered species recovery program efforts (rearing method, release site) were linked to variation in monthly home range size. We found that monthly home range size varied across the annual cycle, with the largest monthly home ranges observed during late summer and early fall (July–October), a pattern that may be linked to seasonal changes in thermals that facilitate movement. Monthly home ranges of adults were significantly larger than those of immatures, but males and females used monthly home ranges of similar size throughout the year and breeding adults did not differ from non-breeding adults in their average monthly home range size. Individuals from each of three release sites differed significantly in the size of their monthly home ranges, and no differences in monthly home range size were detected between condors reared under captive conditions relative to those reared in the wild. Our study provides an important foundation for understanding the movement ecology of the California Condor and it highlights the importance of seasonal variation in space use for effective conservation planning for this critically endangered species.

The population genetics of a solitary oligolectic sweat bee, Lasioglossum (Sphecodogastra) oenotherae (Hymenoptera: Halictidae).

PubMed

Zayed, A; Packer, L

2007-10-01

Strong evidence exists for global declines in pollinator populations. Data on the population genetics of solitary bees, especially diet specialists, are generally lacking. We studied the population genetics of the oligolectic bee Lasioglossum oenotherae, a specialist on the pollen of evening primrose (Onagraceae), by genotyping 455 females from 15 populations across the bee's North American range at six hyper-variable microsatellite loci. We found significant levels of genetic differentiation between populations, even at small geographic scales, as well as significant patterns of isolation by distance. However, using multilocus genotype assignment tests, we detected 11 first-generation migrants indicating that L. oenotherae's sub-populations are experiencing ongoing gene flow. Southern populations of L. oenotherae were significantly more likely to deviate from Hardy-Weinberg equilibrium and from genotypic equilibrium, suggesting regional differences in gene flow and/or drift and inbreeding. Short-term N(e) estimated using temporal changes in allele frequencies in several populations ranged from approximately 223 to 960. We discuss our findings in terms of the conservation genetics of specialist pollinators, a group of considerable ecological importance.

A new quantitative model of ecological compensation based on ecosystem capital in Zhejiang Province, China*

PubMed Central

Jin, Yan; Huang, Jing-feng; Peng, Dai-liang

2009-01-01

Ecological compensation is becoming one of key and multidiscipline issues in the field of resources and environmental management. Considering the change relation between gross domestic product (GDP) and ecological capital (EC) based on remote sensing estimation, we construct a new quantitative estimate model for ecological compensation, using county as study unit, and determine standard value so as to evaluate ecological compensation from 2001 to 2004 in Zhejiang Province, China. Spatial differences of the ecological compensation were significant among all the counties or districts. This model fills up the gap in the field of quantitative evaluation of regional ecological compensation and provides a feasible way to reconcile the conflicts among benefits in the economic, social, and ecological sectors. PMID:19353749

A new quantitative model of ecological compensation based on ecosystem capital in Zhejiang Province, China.

PubMed

Jin, Yan; Huang, Jing-feng; Peng, Dai-liang

2009-04-01

Ecological compensation is becoming one of key and multidiscipline issues in the field of resources and environmental management. Considering the change relation between gross domestic product (GDP) and ecological capital (EC) based on remote sensing estimation, we construct a new quantitative estimate model for ecological compensation, using county as study unit, and determine standard value so as to evaluate ecological compensation from 2001 to 2004 in Zhejiang Province, China. Spatial differences of the ecological compensation were significant among all the counties or districts. This model fills up the gap in the field of quantitative evaluation of regional ecological compensation and provides a feasible way to reconcile the conflicts among benefits in the economic, social, and ecological sectors.

Feeding ecology of Coryphaenoides rupestris from the mid-Atlantic Ridge.

PubMed

Bergstad, Odd Aksel; Gjelsvik, Guro; Schander, Christoffer; Høines, Age S

2010-05-03

The Macrourid fish roundnose grenadier, Coryphaenoides rupestris, is one of the most common benthopelagic fishes on the northern mid-Atlantic Ridge. The ecology of the species is comparatively well studied in continental slope waters of the North Atlantic, but not on the mid-Atlantic Ridge, which is a central mid-ocean area of its distribution. In total, 166 specimens from the RV G.O. Sars cruise in July 2004 were examined. The diet mainly comprised cephalopods, pelagic shrimps and fish. Pelagic and benthopelagic copepods were the most numerous prey, but did not contribute much on a weight basis. Cephalopods were by far the most important prey of the small grenadiers, while shrimps and fish became increasingly significant with increasing size. Previous studies from other areas have also found pelagic prey to be important, but in contrast to this study, cephalopods were generally of less importance. The study was an element of more wide-ranging food-web studies of the mid-Atlantic Ridge macro- and megafauna communities within the international MAR-ECO project.

Development of EST-derived microsatellite markers in the aquatic macrophyte Ranunculus bungei (Ranunculaceae)1

PubMed Central

Wu, Zhigang; Wu, Jinwei; Wang, Yalin; Hou, Hongwei

2017-01-01

Premise of the study: Microsatellite or simple sequence repeat (SSR) markers were developed to investigate the influence of ecological factors on gene flow and spatial genetic structuring of the submerged plant Ranunculus bungei (Ranunculaceae), which is regarded as an important species for understanding how plants adapt to an aquatic environment. Methods and Results: Twenty-two microsatellite loci were identified from an expressed sequence tag (EST) library. The number of alleles per locus ranged from one to five, and the expected heterozygosity varied from 0.0 to 0.5 in four Chinese populations of R. bungei. Fourteen loci were polymorphic and significantly deviated from Hardy–Weinberg equilibrium. All of the loci were found to be amplifiable in two other species of Ranunculus section Batrachium, and cross-amplification in six riparian and aquatic species of Ranunculaceae was also partially successful. Conclusions: These novel EST-SSR markers will be useful for ecological and evolutionary studies of R. bungei as well as related species. PMID:28791205

Sedimentary loadings and ecological significance of polycyclic aromatic hydrocarbons in a typical mariculture zone of South China.

PubMed

Yu, Huan-Yun; Bao, Lian-Jun; Wong, Charles S; Hu, Yuanan; Zeng, Eddy Y

2012-10-26

Two sediment cores were collected from Hailing Bay located in a typical mariculture zone of Guangdong Province, South China, and analyzed for polycyclic aromatic hydrocarbons (PAHs). The concentrations of the sum of 27 PAHs ranged from 62 to 1200 ng g(-1) dry wt, and sediment in the study area was considered to be moderately polluted by PAHs. Source diagnostics based on PAH composition and principal component analysis suggested that PAHs in the study area were mainly derived from petroleum combustion, with discharge of PAHs from fishing boats as an important source. Ecological risk assessment results indicate that PAHs in sediment of the present study currently have minimal adverse effect on the mariculture environment. Comparison of sedimentary inventory of PAHs in the fish harbor of the study area with those in the Pearl River Estuary and the coastal Bohai Bay indicate that the sediment has become an important reservoir of PAHs.

Bioaccumulation and ecological risk assessment of heavy metals in the sediments and mullet Liza klunzingeri in the northern part of the Persian Gulf.

PubMed

Bastami, Kazem Darvish; Afkhami, Majid; Mohammadizadeh, Maria; Ehsanpour, Maryam; Chambari, Shahrokh; Aghaei, Sina; Esmaeilzadeh, Marjan; Neyestani, Mahmoud Reza; Lagzaee, Farahnaz; Baniamam, Mehrnaz

2015-05-15

The concentrations of some heavy metals (Cu, Zn, Pb and Cd) were investigated in the sediments and in the mullet Liza klunzingeri from the northern part of the Persian Gulf. The levels of Cu, Zn and Pb in the sediment varied significantly among the sampling sites (P<0.05). Sediments from the northern part of the Persian Gulf had serious ecological risk when considering PER. The ranges of the average concentrations of Cu, Zn, Pb, and Cd in the tissue of L. klunzingeri were 10.00-16.66 mg/kg, 18.75-32.50 mg/kg, 3.25-14.16 mg/kg and 0.37-3.33 mg/kg, respectively. The health risk analysis of individual heavy metals in the fish tissue indicated dangerous levels of Pb and Cd for the general population at some sampling sites. Copyright © 2015 Elsevier Ltd. All rights reserved.

Thermal barriers constrain microbial elevational range size via climate variability.

PubMed

Wang, Jianjun; Soininen, Janne

2017-08-01

Range size is invariably limited and understanding range size variation is an important objective in ecology. However, microbial range size across geographical gradients remains understudied, especially on mountainsides. Here, the patterns of range size of stream microbes (i.e., bacteria and diatoms) and macroorganisms (i.e., macroinvertebrates) along elevational gradients in Asia and Europe were examined. In bacteria, elevational range size showed non-significant phylogenetic signals. In all taxa, there was a positive relationship between niche breadth and species elevational range size, driven by local environmental and climatic variables. No taxa followed the elevational Rapoport's rule. Climate variability explained the most variation in microbial mean elevational range size, whereas local environmental variables were more important for macroinvertebrates. Seasonal and annual climate variation showed negative effects, while daily climate variation had positive effects on community mean elevational range size for all taxa. The negative correlation between range size and species richness suggests that understanding the drivers of range is key for revealing the processes underlying diversity. The results advance the understanding of microbial species thermal barriers by revealing the importance of seasonal and diurnal climate variation, and highlight that aquatic and terrestrial biota may differ in their response to short- and long-term climate variability. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

Theoretical ecology as etiological from the start.

PubMed

Donhauser, Justin

2016-12-01

The world's leading environmental advisory institutions look to ecological theory and research as an objective guide for policy and resource management decision-making. In addition to the theoretical and broadly philosophical merits of doing so, it is therefore practically significant to clear up confusions about ecology's conceptual foundations and to clarify the basic workings of inferential methods used in the science. Through discussion of key moments in the genesis of the theoretical branch of ecology, this essay elucidates a general heuristic role of teleological metaphors in ecological research and defuses certain enduring confusions about work in ecology. Copyright © 2016. Published by Elsevier Ltd.

Estimation and Application of Ecological Memory Functions in Time and Space

NASA Astrophysics Data System (ADS)

Itter, M.; Finley, A. O.; Dawson, A.

2017-12-01

A common goal in quantitative ecology is the estimation or prediction of ecological processes as a function of explanatory variables (or covariates). Frequently, the ecological process of interest and associated covariates vary in time, space, or both. Theory indicates many ecological processes exhibit memory to local, past conditions. Despite such theoretical understanding, few methods exist to integrate observations from the recent past or within a local neighborhood as drivers of these processes. We build upon recent methodological advances in ecology and spatial statistics to develop a Bayesian hierarchical framework to estimate so-called ecological memory functions; that is, weight-generating functions that specify the relative importance of local, past covariate observations to ecological processes. Memory functions are estimated using a set of basis functions in time and/or space, allowing for flexible ecological memory based on a reduced set of parameters. Ecological memory functions are entirely data driven under the Bayesian hierarchical framework—no a priori assumptions are made regarding functional forms. Memory function uncertainty follows directly from posterior distributions for model parameters allowing for tractable propagation of error to predictions of ecological processes. We apply the model framework to simulated spatio-temporal datasets generated using memory functions of varying complexity. The framework is also applied to estimate the ecological memory of annual boreal forest growth to local, past water availability. Consistent with ecological understanding of boreal forest growth dynamics, memory to past water availability peaks in the year previous to growth and slowly decays to zero in five to eight years. The Bayesian hierarchical framework has applicability to a broad range of ecosystems and processes allowing for increased understanding of ecosystem responses to local and past conditions and improved prediction of ecological processes.

Holocene re-colonisation, central-marginal distribution and habitat specialisation shape population genetic patterns within an Atlantic European grass species.

PubMed

Harter, D E V; Jentsch, A; Durka, W

2015-05-01

Corynephorus canescens (L.) P.Beauv. is an outbreeding, short-lived and wind-dispersed grass species, highly specialised on scattered and disturbance-dependent habitats of open sandy sites. Its distribution ranges from the Iberian Peninsula over Atlantic regions of Western and Central Europe, but excludes the two other classical European glacial refuge regions on the Apennine and Balkan Peninsulas. To investigate genetic patterns of this uncommon combination of ecological and biogeographic species characteristics, we analysed AFLP variation among 49 populations throughout the European distribution range, expecting (i) patterns of SW European glacial refugia and post-glacial expansion to the NE; (ii) decreasing genetic diversity from central to marginal populations; and (iii) interacting effects of high gene flow and disturbance-driven genetic drift. Decreasing genetic diversity from SW to NE and distinct gene pool clustering imply refugia on the Iberian Peninsula and in western France, from where range expansion originated towards the NE. High genetic diversity within and moderate genetic differentiation among populations, and a significant pattern of isolation-by-distance indicate a gene flow drift equilibrium within C. canescens, probably due to its restriction to scattered and dynamic habitats and limited dispersal distances. These features, as well as the re-colonisation history, were found to affect genetic diversity gradients from central to marginal populations. Our study emphasises the need for including the specific ecology into analyses of species (re-)colonisation histories and range centre-margin analyses. To account for discontinuous distributions, new indices of marginality were tested for their suitability in studies of centre-periphery gradients. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

Geochemical Indicators of Nitrogen flow in a Check-Dam Catchment in the Loess Plateau, China

NASA Astrophysics Data System (ADS)

Wang, Y.; Chen, S.; Huang, Y.; Gao, Y.

2017-12-01

The increasingly fragile ecological environment and associative nitrogen (N) biogeochemical cycle have become critical environmental and ecological issues in China's Loess Plateau. However, N flow and N source for typical catchments remains poorly understood in the Loess Plateau. In this study, we measured concentrations and isotopic signatures of N, hydrogen (H), and oxygen (O) in both rainfall and river water. Results showed that baseflow variation in total nitrogen (TN) concentrations ranged from 0.16 to 32.70 mg·L-1. Monthly TN deposition and monthly N wet deposition concentrations to river water were from 0.05 to 2.91 kg·hm-2 and from 0.28 to 11.26 kg, respectively, with significant variations between rainy and dry seasons. The range of variation in δ2H values for rainfall and baseflow were from -90.0‰ to +19.8‰ and from -67.2‰ to -38.4‰, respectively, while δ18O-H2O values ranged from -12.1‰ to +2.7‰ and from -9.3‰ to -3.6‰, respectively. Furthermore, NO3- δ15N and δ18O values in baseflow ranged from -2.0‰ to +20.5‰ and from +8.0‰ to +15.6‰, respectively. The results indicated that rainfall was affected by below-cloud secondary evaporation and caused strong isotopic kinetic fractionation to occur during the falling process. The NO3-in runoff mainly derived from the nitrification of soil organic matter (SOM), for which the proportion of manure or sewage was from 50.5% to 83%.

An Ecological Paradox: The African Wild Dog (Lycaon Pictus) Is Not Attracted to Water Points When Water Is Scarce in Hwange National Park, Zimbabwe.

PubMed

Ndaimani, Henry; Tagwireyi, Paradzayi; Sebele, Lovelater; Madzikanda, Hillary

2016-01-01

In dry biomes, spatio-temporal variation in surface water resource stocks is pervasive, with unknown effects on the ranging behaviour of large predators. This study assessed the effect of spatial variation in surface water resources on the ranging behaviour of the African wild dog (Lycaon pictus). We analyzed data for 1992 (dry year with 20 water points) and 2000 (wet year with 30 water points) against presence-only data for five packs of L. pictus in a part of Hwange National Park and adjacent smallholder communal farming areas in western Zimbabwe. Modelling the potential habitat for L. pictus using Maxent with distance from water points (Dw) and Normalized Difference Vegetation Index (NDVI) as predictor variables was successful for 2000 (AUC = 0.793) but not successful for 1992 (AUC = 0.423), with L. pictus probability of occurrence near water points being more for year 2000 than for year 1992. The predicted L. pictus range was wider in 1992 (~13888.1 km2) than in 2000 (~958.4 km2) (Test of Proportions, χ2 = 124.52, df = 1, P = 0.00). Using the 2nd order Multitype Nearest Neighbour Distance Function (Gcross), we also observed significant attraction between L. pictus and water points within only ~1km radius for 1992 but up to ~8km radius for 2000. Our study reinforced the notion that surface water resources attract wild dogs in the savannahs but paradoxically less so when water resources are scarce. In particular, our study furthers current understanding of the effects of changing water availability regimes on the endangered L. pictus, providing evidence that the endangered predator's home range encroaches into potential ecological traps (i.e., smallholder communal farming areas) when water resources are scarce.

Age-related variation in body temperature, thermoregulation and activity in a thermally polymorphic dragonfly

PubMed

Marden; Kramer; Frisch

1996-01-01

Thoracic temperatures (Tth) of Libellula pulchella dragonflies during activity in the field were compared between age classes and with laboratory measures of optimal thoracic temperature for flight performance (Tth,opt; a trait that varies during adult maturation in this species). Newly emerged adults (tenerals) had mean Tth values during flight (34.5 °C; range 29-40 °C) that did not differ from their mean Tth,opt (34.6 °C; range 28.5-43.8 °C). Mature adults had higher and more precisely regulated thoracic temperatures (mean Tth 41.7 °C; range 37.5-45.2 °C), which were somewhat lower than their mean Tth,opt (43.6 °C; range 38.7-49.9 °C). Among matures, behaviors requiring the highest levels of flight exertion (aerial copulation; mate guarding; escalated territorial contests) caused an elevation of Tth above that of concurrently sampled individuals engaged in routine flight (mean Tth difference 1.3 °C), which raised mean Tth to a level that was not significantly different from Tth,opt (42.5 versus 43.5 °C). Compared with tenerals, matures spent more time flying, made longer-duration flights and showed a more restricted pattern of daily activity. Sympatric Anax junius dragonflies that regulate Tth endothermically had a uniform pattern of activity across the entire day, i.e. occupied a broader ecological niche than that of L. pulchella. These results support the hypotheses that optimal body temperature evolves to match the elevated body temperatures that occur during exercise and that the ecological benefits of an expanded niche are a secondary benefit rather than a primary selective force during the evolution of homeothermy and high body temperatures.

Assessment of the Natural Environment.

ERIC Educational Resources Information Center

Cantrell, Mary Lynn; Cantrell, Robert P.

1985-01-01

Basic assumptions of an ecological-behavioral view of assessing behavior disordered students are reviewed along with a proposed method for ecological analysis and specific techniques for measuring ecological variables (such as environmental units, behaviors of significant others, and behavioral expectations). The use of such information in program…

Ponderosa pine ecosystems restoration and conservation: steps toward stewardship; 2000 April 25-27; Flagstaff, AZ

Treesearch

Regina K. Vance; Carleton B. Edminster; W. Wallace Covington; Julie A. Blake

2000-01-01

This volume is divided into three sections: (1) Ecological, Biological, and Physical Science; (2) Social and Cultural; and (3) Economics and Utilization. Effective ecological restoration requires a combination of science and management. The authors of the first section exemplified this integration in the course of addressing a broad range of topics, from detailed...

Objectives and study design of the Colville study: silviculture, ecology, utilization, and economics of small-diameter densely stocked stands.

Treesearch

R.J. Barbour; S.D. Tesch; J. McNeel; S.A. Willits; R.D. Fight; A. Mason; K.E. Skog

1997-01-01

Public land managers in the United States are increasingly interested in managing forests to provide a range of ecological and social outputs in addition to timber. These outputs might include healthy riparian areas, connected blocks of late-successional forests, habitat for threatened and endangered species, and high quality recreational opportunities. On National...

Ecological mindfulness, spirituality, and life-long (hybrid, dialogical) learning: a tribute to Michiel van Eijck

NASA Astrophysics Data System (ADS)

Roth, Wolff-Michael

2015-03-01

In this tribute, I articulate the contributions Michiel van Eijck made to science education, as experienced through our relation, which ranged from supervisor and colleague to friend. His ecological thinking about human knowing, which was reflected in his spiritual inclinations, constitutes his legacy that will have an impact on our field for years to come.

Ecological and economic impacts of forest policies: interactions across forestry and agriculture.

Treesearch

R.J. Alig; D.M. Adams; B.A. McCarl

1998-01-01

A linked model of the US forest and agriculture sectors was used to examine the economic and ecological impacts of two forest policies: a minimum harvest age limitation and a reduced public harvest policy. Simulated private responses to both policies indicate that landowners could undertake a range of adjustments to minimize their welfare impacts, but imposition of...

Ecological Correlates of Spanish Adolescents' Physical Activity during Physical Education Classes

ERIC Educational Resources Information Center

Molina-García, Javier; Queralt, Ana; Estevan, Isaac; Sallis, James F.

2016-01-01

The public health benefit of school physical education (PE) depends in large part on physical activity (PA) provided during class. According to the literature, PE has a valuable role in public health, and PA levels during PE classes depend on a wide range of factors. The main objective of this study, based on ecological models of behaviour, was to…

Case Study: Crazy about Cryptids--An Ecological Hunt for Nessie and Other Legendary Creatures

ERIC Educational Resources Information Center

Rowe, Matthew P.

2015-01-01

This column provides original articles on innovations in case study teaching, assessment of the method, as well as case studies with teaching notes. This hybrid case has three overarching and interrelated goals. First, it can be used to familiarize students with a range of ecological concepts and terms. Second, it is intended to engage students in…

Helicopter logging productivity on harvesting operations in southeast Alaska, using ecologically based silvicultural prescriptions.

Treesearch

L. Christian; A. Brackley

2007-01-01

This study examines production rates and costs for felling and helicopter yarding on eight units harvested in accordance with ecologically based silvicultural prescriptions. The units represent five levels of basal area retention. The levels of retention had irregular spatial arrangements caused by gaps and clumps that ranged from 0 percent retention (clearcut) to 75...

Southwestern U. S. juniper savanna and piñon-juniper woodland communities: Ecological history and natural range of variability

Treesearch

Brian F. Jacobs

2008-01-01

Juniper savanna and pinon-juniper woodland communities collectively represent a widespread and diverse vegetation type that occupies foothill and mesa landforms at middle elevations in semi-arid portions of the American Southwest. Ecological understanding and proper management of these juniper and pinon types requires local knowledge of component species, site history...

Social science in the context of the long term ecological research program

Treesearch

Ted L. Gragson; Morgan Grove

2006-01-01

This special issue of Society and Natural Resources brings the results of long-term ecological research with an explicit social dimension to the attention of the social scientific research community. Contributions are from the Baltimore Ecosystem Study LTER, the Central Arizona-Phoenix LTER, the Coweeta LTER and the Northern Temperate Lakes LTER The range of practice...

Social science in the context of the long term ecological research program

Treesearch

Ted L. Gragson; Morgan Grove

2006-01-01

This special issue of Society and Natural Resources brings the results of long-term ecological research with an explicit social dimension to the attention of the social scientific research community. Contributions are from the Baltimore Ecosystem Study LTER, the Central Arizona-Phoenix LTER, the Coweeta LTER and the Northern Temperate Lakes LTER. The range of practice...

Wildland Fire Use - Challenges Associated With Program Management Across Multiple Ownerships and Land Use Situations

Treesearch

Thomas Zimmerman; Michael Frary; Shelly Crook; Brett Fay; Patricia Koppenol; Richard Lasko

2006-01-01

The application and use of wildland fire for a range of beneficial ecological objectives is rapidly expanding across landscapes supporting diverse vegetative complexes and subject to multiple societal uses. Wildland fire use originated in wilderness and has become a proven practice successful in meeting ecological needs. The use of wildland fire in non-wilderness is...

REECo activities and sample logistics in support of the Nevada Applied Ecology Group

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wireman, D.L.; Rosenberry, C.E. Jr.; White, M.G.

Activities and sample logistics of Reynolds Electrical and Engineering Co., Inc. (REECo), in support of the Nevada Applied Ecology Group (NAEG), are discussed in this summary report. Activities include the collection, preparation, and shipment of samples of soils, vegetation, and small animals collected at Pu-contaminated areas of the Nevada Test Site and Tonopah Test Range. (CH)

Chapter 2: The Asian Race of the Marbled Murrelet

Treesearch

Nikolai B. Konyukhov; Alexander S. Kitaysky

1995-01-01

We present here an overview of the ecology, abundance, and distribution of the subspecies of the Marbled Murrelet inhabiting the coasts of Asia. In most regards, the species is similar to the North American race with respect to its feeding, breeding, molt, and habitat ecology. It is, however, a migratory species, moving into southern parts of its range in the Sea of...

Compounding Impacts of Climate Change and Increased Human Water Withdrawal on Urmia Lake Water Availability

NASA Astrophysics Data System (ADS)

Alborzi, A.; Moftakhari, H.; Azaranfar, A.; Mallakpour, I.; Ashraf, B.; AghaKouchak, A.

2017-12-01

In recent decades, climate change and increase in human water withdrawal, combined, have caused ecological degradation in several terminal lakes worldwide. Among them, the shallow and hyper-saline Urmia Lake in Iran has experienced about 6 meters drawdown in lake level and 80% reduction in surface area. Here, we assess the imposed stress on Urmia Basin's water availability and Lake's ecological condition in response to coupled climate change and human-induced water withdrawal. A generalized river basin decision support system model consisting network flow is developed to simulate the basin-lake interactions under a wide range of scenarios. This model explicitly includes water management infrastructure, reservoirs, and irrigation and municipal water use. Studied scenarios represent a wide range of historic climate and water use scenarios including a historical baseline, future increase in water demand, and also improved water efficiency. In this presentation, we show the lake's water level, as a measure of lake's ecological health, under the compounding effects of the climate condition (top-down) and water use (bottom-up) scenarios. This method illustrates what combinations lead to failure in meeting the lake's ecological level.

The pitfalls of short-range endemism: high vulnerability to ecological and landscape traps.

PubMed

Mason, Leanda D; Bateman, Philip W; Wardell-Johnson, Grant W

2018-01-01

Ecological traps attract biota to low-quality habitats. Landscape traps are zones caught in a vortex of spiralling degradation. Here, we demonstrate how short-range endemic (SRE) traits may make such taxa vulnerable to ecological and landscape traps. Three SRE species of mygalomorph spider were used in this study: Idiommata blackwalli, Idiosoma sigillatum and an undescribed Aganippe sp. Mygalomorphs can be long-lived (>43 years) and select sites for permanent burrows in their early dispersal phase. Spiderlings from two species, I. blackwalli ( n = 20) and Aganippe sp. ( n = 50), demonstrated choice for microhabitats under experimental conditions, that correspond to where adults typically occur in situ . An invasive veldt grass microhabitat was selected almost exclusively by spiderlings of I. sigillatum . At present, habitat dominated by veldt grass in Perth, Western Australia, has lower prey diversity and abundance than undisturbed habitats and therefore may act as an ecological trap for this species. Furthermore, as a homogenising force, veldt grass can spread to form a landscape trap in naturally heterogeneous ecosystems. Selection of specialised microhabitats of SREs may explain high extinction rates in old, stable landscapes undergoing (human-induced) rapid change.

Re-evaluating the link between brain size and behavioural ecology in primates.

PubMed

Powell, Lauren E; Isler, Karin; Barton, Robert A

2017-10-25

Comparative studies have identified a wide range of behavioural and ecological correlates of relative brain size, with results differing between taxonomic groups, and even within them. In primates for example, recent studies contradict one another over whether social or ecological factors are critical. A basic assumption of such studies is that with sufficiently large samples and appropriate analysis, robust correlations indicative of selection pressures on cognition will emerge. We carried out a comprehensive re-examination of correlates of primate brain size using two large comparative datasets and phylogenetic comparative methods. We found evidence in both datasets for associations between brain size and ecological variables (home range size, diet and activity period), but little evidence for an effect of social group size, a correlation which has previously formed the empirical basis of the Social Brain Hypothesis. However, reflecting divergent results in the literature, our results exhibited instability across datasets, even when they were matched for species composition and predictor variables. We identify several potential empirical and theoretical difficulties underlying this instability and suggest that these issues raise doubts about inferring cognitive selection pressures from behavioural correlates of brain size. © 2017 The Author(s).

Climate change and ecosystem disruption: the health impacts of the North American Rocky Mountain pine beetle infestation.

PubMed

Embrey, Sally; Remais, Justin V; Hess, Jeremy

2012-05-01

In the United States and Canada, pine forest ecosystems are being dramatically affected by an unprecedented pine beetle infestation attributed to climate change. Both decreased frequency of extremely cold days and warmer winter temperature averages have led to an enphytotic devastating millions of acres of pine forest. The associated ecosystem disruption has the potential to cause significant health impacts from a range of exposures, including increased runoff and water turbidity, forest fires, and loss of ecosystem services. We review direct and indirect health impacts and possible prevention strategies. The pine beetle infestation highlights the need for public health to adopt an ecological, systems-oriented view to anticipate the full range of potential health impacts from climate change and facilitate effective planned adaptation.

Climate Change and Ecosystem Disruption: The Health Impacts of the North American Rocky Mountain Pine Beetle Infestation

PubMed Central

Remais, Justin V.; Hess, Jeremy

2012-01-01

In the United States and Canada, pine forest ecosystems are being dramatically affected by an unprecedented pine beetle infestation attributed to climate change. Both decreased frequency of extremely cold days and warmer winter temperature averages have led to an enphytotic devastating millions of acres of pine forest. The associated ecosystem disruption has the potential to cause significant health impacts from a range of exposures, including increased runoff and water turbidity, forest fires, and loss of ecosystem services. We review direct and indirect health impacts and possible prevention strategies. The pine beetle infestation highlights the need for public health to adopt an ecological, systems-oriented view to anticipate the full range of potential health impacts from climate change and facilitate effective planned adaptation. PMID:22420788

Pollinators, pests, and predators: Recognizing ecological trade-offs in agroecosystems.

PubMed

Saunders, Manu E; Peisley, Rebecca K; Rader, Romina; Luck, Gary W

2016-02-01

Ecological interactions between crops and wild animals frequently result in increases or declines in crop yield. Yet, positive and negative interactions have mostly been treated independently, owing partly to disciplinary silos in ecological and agricultural sciences. We advocate a new integrated research paradigm that explicitly recognizes cost-benefit trade-offs among animal activities and acknowledges that these activities occur within social-ecological contexts. Support for this paradigm is presented in an evidence-based conceptual model structured around five evidence statements highlighting emerging trends applicable to sustainable agriculture. The full range of benefits and costs associated with animal activities in agroecosystems cannot be quantified by focusing on single species groups, crops, or systems. Management of productive agroecosystems should sustain cycles of ecological interactions between crops and wild animals, not isolate these cycles from the system. Advancing this paradigm will therefore require integrated studies that determine net returns of animal activity in agroecosystems.

Evolution and ecology of retinal photoreception in early vertebrates.

PubMed

Collin, Shaun P

2010-01-01

Visual ecology or the relationship between the visual system of an animal and its environment has proven to be a crucial research field for establishing general concepts of adaptation, specialization and evolution. The visual neuroscientist is indeed confronted with a plethora of different visual characteristics, each seemingly optimised for each species' ecological niche, but often without a clear understanding of the evolutionary constraints at play. However, before we are able to fully understand the influence(s) of ecology and phylogeny on visual system design in vertebrates, it is first necessary to understand the basic bauplan of key representatives of each taxa. This review examines photoreception in hagfishes, lampreys, cartilaginous fishes and lungfishes with an eye to their ecology using a range of neurobiological methods including anatomy, microspectrophotometry and molecular genetics. These early vertebrates represent critical stages in evolution and surprisingly possess a level of visual complexity that is almost unrivalled in other vertebrates. 2010 S. Karger AG, Basel.

Improved probability of detection of ecological “surprises”

PubMed Central

Lindenmayer, D. B.; Likens, G. E.; Krebs, C. J.; Hobbs, R. J.

2010-01-01

Ecological “surprises” are defined as unexpected findings about the natural environment. They are critically important in ecology because they are catalysts for questioning and reformulating views of the natural world, help shape assessments of the veracity of a priori predictions about ecological trends and phenomena, and underpin questioning of effectiveness of resource management. Despite the importance of ecological surprises, major gaps in understanding remain about how studies might be done differently or done better to improve the ability to identify them. We outline the kinds of ecological surprises that have arisen from long-term research programs that we lead in markedly different ecosystems around the world. Based on these case studies, we identify important lessons to guide both existing studies and new investigations to detect ecological surprises more readily, better anticipate unusual ecological phenomena, and take proactive steps to plan for and alleviate “undesirable” ecological surprises. Some of these lessons include: (i) maintain existing, and instigate new, long-term studies; (ii) conduct a range of kinds of parallel and concurrent research in a given target area; (iii) better use past literature and conceptual models of the target ecosystem in posing good questions and developing hypotheses and alternative hypotheses; and (iv) increase the capacity for ecological research to take advantage of opportunities arising from major natural disturbances. We argue that the increased anticipatory capability resulting from these lessons is critical given that ecological surprises may become more prevalent because of climate change and multiple and interacting environmental stressors. PMID:21098660

Impact of Geography and Climate on the Genetic Differentiation of the Subtropical Pine Pinus yunnanensis

PubMed Central

Zhao, Wei; Wang, Xiao-Ru

2013-01-01

Southwest China is a biodiversity hotspot characterized by complex topography, heterogeneous regional climates and rich flora. The processes and driving factors underlying this hotspot remain to be explicitly tested across taxa to gain a general understanding of the evolution of biodiversity and speciation in the region. In this study, we examined the role played by historically neutral processes, geography and environment in producing the current genetic diversity of the subtropical pine Pinus yunnanensis. We used genetic and ecological methods to investigate the patterns of genetic differentiation and ecological niche divergence across the distribution range of this species. We found both continuous genetic differentiation over the majority of its range, and discrete isolated local clusters. The discrete differentiation between two genetic groups in the west and east peripheries is consistent with niche divergence and geographical isolation of these groups. In the central area of the species’ range, population structure was shaped mainly by neutral processes and geography rather than by ecological selection. These results show that geographical and environmental factors together created stronger and more discrete genetic differentiation than isolation by distance alone, and illustrate the importance of ecological factors in forming or maintaining genetic divergence across a complex landscape. Our findings differ from other phylogenetic studies that identified the historical drainage system in the region as the primary factor shaping population structure, and highlight the heterogeneous contributions that geography and environment have made to genetic diversity among taxa in southwest China. PMID:23840668

Impact of Geography and Climate on the Genetic Differentiation of the Subtropical Pine Pinus yunnanensis.

PubMed

Wang, Baosheng; Mao, Jian-Feng; Zhao, Wei; Wang, Xiao-Ru

2013-01-01

Southwest China is a biodiversity hotspot characterized by complex topography, heterogeneous regional climates and rich flora. The processes and driving factors underlying this hotspot remain to be explicitly tested across taxa to gain a general understanding of the evolution of biodiversity and speciation in the region. In this study, we examined the role played by historically neutral processes, geography and environment in producing the current genetic diversity of the subtropical pine Pinus yunnanensis. We used genetic and ecological methods to investigate the patterns of genetic differentiation and ecological niche divergence across the distribution range of this species. We found both continuous genetic differentiation over the majority of its range, and discrete isolated local clusters. The discrete differentiation between two genetic groups in the west and east peripheries is consistent with niche divergence and geographical isolation of these groups. In the central area of the species' range, population structure was shaped mainly by neutral processes and geography rather than by ecological selection. These results show that geographical and environmental factors together created stronger and more discrete genetic differentiation than isolation by distance alone, and illustrate the importance of ecological factors in forming or maintaining genetic divergence across a complex landscape. Our findings differ from other phylogenetic studies that identified the historical drainage system in the region as the primary factor shaping population structure, and highlight the heterogeneous contributions that geography and environment have made to genetic diversity among taxa in southwest China.

Cryptic diversity in a fig wasp community-morphologically differentiated species are sympatric but cryptic species are parapatric.

PubMed

Darwell, C T; Cook, J M

2017-02-01

A key debate in ecology centres on the relative importance of niche and neutral processes in determining patterns of community assembly with particular focus on whether ecologically similar species with similar functional traits are able to coexist. Meanwhile, molecular studies are increasingly revealing morphologically indistinguishable cryptic species with presumably similar ecological roles. Determining the geographic distribution of such cryptic species provides opportunities to contrast predictions of niche vs. neutral models. Discovery of sympatric cryptic species increases alpha diversity and supports neutral models, while documentation of allopatric/parapatric cryptic species increases beta diversity and supports niche models. We tested these predictions using morphological and molecular data, coupled with environmental niche modelling analyses, of a fig wasp community along its 2700-km latitudinal range. Molecular methods increased previous species diversity estimates from eight to eleven species, revealing morphologically cryptic species in each of the four wasp genera studied. Congeneric species pairs that were differentiated by a key morphological functional trait (ovipositor length) coexisted sympatrically over large areas. In contrast, morphologically similar species, with similar ovipositor lengths, typically showed parapatric ranges with very little overlap. Despite parapatric ranges, environmental niche models of cryptic congeneric pairs indicate large regions of potential sympatry, suggesting that competitive processes are important in determining the distributions of ecologically similar species. Niche processes appear to structure this insect community, and cryptic diversity may typically contribute mostly to beta rather than alpha diversity. © 2016 John Wiley & Sons Ltd.

Using GPS Transmitters to Explore Movement Ecology and to Assess Risk of the Wind Energy Industry for Swainson's Hawks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Watson, Katheryn A.; Boal, Clint W.; Groen, Laurie M.

Swainson’s hawks (Buteo swainsoni) are a long-distance migratory species that breed in western North America and winter in Argentina. As a grassland species, they can also be found in agricultural settings, such as croplands and pastures. Wind energy is expanding rapidly across the breeding range of the population we chose to study, and we suspect the industry is also expanding in their wintering range and across the migratory pathway. Wind turbines pose a threat to birds, and migratory species may be especially susceptible to turbine-related mortality when these structures are placed in important migratory pathways. The purposes of this longtermmore » study were to examine potential threats that wind energy might pose to Swainson’s hawks on the breeding range, wintering range, and during migration, add to the body of ecological knowledge on migration and wintering habits, and describe breeding habits in a portion of their range that is relatively understudied.« less

Spatial Ecology of the Critically Endangered Fijian Crested Iguana, Brachylophus vitiensis, in an Extremely Dense Population: Implications for Conservation

PubMed Central

Morrison, Suzanne F.; Biciloa, Pita; Harlow, Peter S.; Keogh, J. Scott

2013-01-01

The Critically Endangered Fijian crested iguana, Brachylophus vitiensis, occurs at extreme density at only one location, with estimates of >10,000 iguanas living on the 70 hectare island of Yadua Taba in Fiji. We conducted a mark and recapture study over two wet seasons, investigating the spatial ecology and intraspecific interactions of the strictly arboreal Fijian crested iguana. This species exhibits moderate male-biased sexual size dimorphism, which has been linked in other lizard species to territoriality, aggression and larger male home ranges. We found that male Fijian crested iguanas exhibit high injury levels, indicative of frequent aggressive interactions. We did not find support for larger home range size in adult males relative to adult females, however male and female residents were larger than roaming individuals. Males with established home ranges also had larger femoral pores relative to body size than roaming males. Home range areas were small in comparison to those of other iguana species, and we speculate that the extreme population density impacts considerably on the spatial ecology of this population. There was extensive home range overlap within and between sexes. Intersexual overlap was greater than intrasexual overlap for both sexes, and continuing male-female pairings were observed among residents. Our results suggest that the extreme population density necessitates extensive home range overlap even though the underlying predictors of territoriality, such as male biased sexual size dimorphism and high aggression levels, remain. Our findings should be factored in to conservation management efforts for this species, particularly in captive breeding and translocation programs. PMID:24019902

Spatial ecology of the critically endangered Fijian crested iguana, Brachylophus vitiensis, in an extremely dense population: implications for conservation.

PubMed

Morrison, Suzanne F; Biciloa, Pita; Harlow, Peter S; Keogh, J Scott

2013-01-01

The Critically Endangered Fijian crested iguana, Brachylophus vitiensis, occurs at extreme density at only one location, with estimates of >10,000 iguanas living on the 70 hectare island of Yadua Taba in Fiji. We conducted a mark and recapture study over two wet seasons, investigating the spatial ecology and intraspecific interactions of the strictly arboreal Fijian crested iguana. This species exhibits moderate male-biased sexual size dimorphism, which has been linked in other lizard species to territoriality, aggression and larger male home ranges. We found that male Fijian crested iguanas exhibit high injury levels, indicative of frequent aggressive interactions. We did not find support for larger home range size in adult males relative to adult females, however male and female residents were larger than roaming individuals. Males with established home ranges also had larger femoral pores relative to body size than roaming males. Home range areas were small in comparison to those of other iguana species, and we speculate that the extreme population density impacts considerably on the spatial ecology of this population. There was extensive home range overlap within and between sexes. Intersexual overlap was greater than intrasexual overlap for both sexes, and continuing male-female pairings were observed among residents. Our results suggest that the extreme population density necessitates extensive home range overlap even though the underlying predictors of territoriality, such as male biased sexual size dimorphism and high aggression levels, remain. Our findings should be factored in to conservation management efforts for this species, particularly in captive breeding and translocation programs.

Patterns and determinants of mammal species occurrence in India

USGS Publications Warehouse

Karanth, K.K.; Nichols, J.D.; Hines, J.E.; Karanth, K.U.; Christensen, N.L.

2009-01-01

Many Indian mammals face range contraction and extinction, but assessments of their population status are hindered by the lack of reliable distribution data and range maps. 2. We estimated the current geographical ranges of 20 species of large mammals by applying occupancy models to data from country-wide expert. We modelled species in relation to ecological and social covariates (protected areas, landscape characteristics and human influences) based on a priori hypotheses about plausible determinants of mammalian distribution patterns. 3. We demonstrated that failure to incorporate detection probability in distribution survey methods underestimated habitat occupancy for all species. 4. Protected areas were important for the distribution of 16 species. However, for many species much of their current range remains unprotected. The availability of evergreen forests was important for the occurrence of 14 species, temperate forests for six species, deciduous forests for 15 species and higher altitude habitats for two species. Low human population density was critical for the occurrence of five species, while culturally based tolerance was important for the occurrence of nine other species. 5. Rhino Rhinoceros unicornis, gaur Bos gaurus and elephant Elephas maximus showed the most restricted ranges among herbivores, and sun bear Helarctos malayanus, brown bear Ursus arctos and tiger Panthera tigris were most restricted among carnivores. While cultural tolerance has helped the survival of some mammals, legal protection has been critically associated with occurrence of most species. 6. Synthesis and applications. Extent of range is an important determinant of species conservation status. Understanding the relationship of species occurrence with ecological and socio-cultural covariates is important for identification and management of key conservation areas. The combination of occupancy models with field data from country-wide experts enables reliable estimation of species range and habitat associations for conservation at regional scales. ?? 2009 British Ecological Society.

[Process of land use transition and its impact on regional ecological quality in the Middle Reaches of Heihe River, China].

PubMed

Wang, Fu Hong; Zhao, Rui Feng; Zhang, Li Hua; Li, Hong Wei

2017-12-01

Land use transition is one of the main drivers of regional ecosystem change in arid area, which directly affects human well-being. Based on the satellite images of 1987, 2001 and 2016, the change detection assessment model and ecological response model were used to analyze the process of land use transition and response of ecological quality during 1987-2016 in the ecologically fragile middle reaches of the Heihe River. The results showed that the land use change was significant during 1987-2016 and the total change increased significantly, as well as the continuous increase of the cultivated land and construction land. There was a strong tendency of transform from grassland to cultivated land, while the tendency of transforming unused land to other land classes was not strong under a random process of gain or loss. During 1987-2016, the ecological quality of the study area displayed a decreasing trend as a whole and the ecological land decreased by 2.8%. The land use transition with the greatest impact on the ecological environment degradation was the transition of the grassland to the cultivated land and unused land. Therefore, in order to promote the sustainable use of regional land resources and to improve the regional ecological quality, it is necessary to allocate the proportion of production land and ecological land according to the regional water resources.

The regional ecology of alternative states and thresholds: Strategies for ecological site descriptions

USDA-ARS?s Scientific Manuscript database

Land dynamics, ecosystem resilience, and the interaction of management decisions with them vary significantly across space. One-size-fits-all applications across distinct land types have been responsible for many failures in rangeland management. Ecological Site Descriptions (ESDs) and similar lan...

Life on the edge: carnivore body size variation is all over the place

PubMed Central

Meiri, Shai; Dayan, Tamar; Simberloff, Daniel; Grenyer, Richard

2009-01-01

Evolutionary biologists have long been fascinated by both the ways in which species respond to ecological conditions at the edges of their geographic ranges and the way that species' body sizes evolve across their ranges. Surprisingly, though, the relationship between these two phenomena is rarely studied. Here, we examine whether carnivore body size changes from the interior of their geographic range towards the range edges. We find that within species, body size often varies strongly with distance from the range edge. However, there is no general tendency across species for size to be either larger or smaller towards the edge. There is some evidence that the smallest guild members increase in size towards their range edges, but results for the largest guild members are equivocal. Whether individuals vary in relation to the distance from the range edges often depends on the way edge and interior are defined. Neither geographic range size nor absolute body size influences the tendency of size to vary with distance from the range edge. Therefore, we suggest that the frequent significant association between body size and the position of individuals along the edge-core continuum reflects the prevalence of geographic size variation and that the distance to range edge per se does not influence size evolution in a consistent way. PMID:19324818

Diversity of Entomopathogenic Fungi: Which Groups Conquered the Insect Body?

PubMed

Araújo, J P M; Hughes, D P

2016-01-01

The entomopathogenic fungi are organisms that evolved to exploit insects. They comprise a wide range of morphologically, phylogenetically, and ecologically diverse fungal species. Entomopathogenic fungi can be found distributed among five of the eight fungal phyla. Entomopathogens are also present among the ecologically similar but phylogenetically distinct Oomycota or water molds, which belong to a different kingdom, the Stramenopila. As a group of parasites, the entomopathogenic fungi and water molds infect a wide range of insect hosts, from aquatic larvae to adult insects from high canopies in tropical forests or even deserts. Their hosts are spread among 20 of the 31 orders of insects, in all developmental stages: eggs, larvae, pupae, nymphs, and adults. Such assortment of niches has resulted in these parasites evolving a considerable morphological diversity, resulting in enormous biodiversity, the majority of which remains unknown. Here we undertake a comprehensive survey of records of these entomopathogens in order to compare and contrast both their morphologies and their ecological traits. Our findings highlight a wide range of adaptations that evolved following the evolutionary transition by the fungi and water molds to infect the most diverse and widespread animals on Earth, the insects. Copyright © 2016 Elsevier Inc. All rights reserved.

Behaviour and Ecology of Male Aye-Ayes (Daubentonia madagascariensis) in the Kianjavato Classified Forest, South-Eastern Madagascar.

PubMed

Randimbiharinirina, Doménico Roger; Raharivololona, Brigitte M; Hawkins, Melissa T R; Frasier, Cynthia L; Culligan, Ryan R; Sefczek, Timothy M; Randriamampionona, Richard; Louis, Edward E

2018-01-01

Previous studies found that aye-ayes (Daubentonia madagascariensis) consume a variety of non-invertebrate resources, supporting the hypothesis that aye-ayes are too large-bodied to focus feeding efforts on insects. However, these conclusions were based on introduced populations, with little known about aye-aye behaviour and ecology in its natural habitat. This study investigates activity budgets, diet, and home range/territories of 2 male aye-ayes in the Kianjavato Classified Forest, a disturbed forest in south-eastern Madagascar, from October 2013 to October 2014. We used radiotelemetry and focal-animal sampling methods to collect behavioural data. We recorded GPS coordinates of the focal animal every 20 min, calculating the home range size for each individual. Results showed that male aye-ayes spent most of their time feeding and travelling. Their feeding time primarily focussed on larvae and adult insects from various substrates, and to a lesser extent Canarium spp. seeds. Home range sizes of the 2 males varied between individuals, overlapped greatly, and appeared to be related to the location of females. Our findings indicate that aye-aye behaviours are strongly indicative of insect-centric feeding ecology. © 2018 S. Karger AG, Basel.

Colony-level behavioural variation correlates with differences in expression of the foraging gene in red imported fire ants.

PubMed

Bockoven, Alison A; Coates, Craig J; Eubanks, Micky D

2017-11-01

Among social insects, colony-level variation is likely to be widespread and has significant ecological consequences. Very few studies, however, have documented how genetic factors relate to behaviour at the colony level. Differences in expression of the foraging gene have been associated with differences in foraging and activity of a wide variety of organisms. We quantified expression of the red imported fire ant foraging gene (sifor) in workers from 21 colonies collected across the natural range of Texas fire ant populations, but maintained under standardized, environmentally controlled conditions. Colonies varied significantly in their behaviour. The most active colonies had up to 10 times more active foragers than the least active colony and more than 16 times as many workers outside the nest. Expression differences among colonies correlated with this colony-level behavioural variation. Colonies with higher sifor expression in foragers had, on average, significantly higher foraging activity, exploratory activity and recruitment to nectar than colonies with lower expression. Expression of sifor was also strongly correlated with worker task (foraging vs. working in the interior of the nest). These results provide insight into the genetic and physiological processes underlying collective differences in social behaviour. Quantifying variation in expression of the foraging gene may provide an important tool for understanding and predicting the ecological consequences of colony-level behavioural variation. © 2017 John Wiley & Sons Ltd.

The adaptive significance of adult neurogenesis: an integrative approach

PubMed Central

Konefal, Sarah; Elliot, Mick; Crespi, Bernard

2013-01-01

Adult neurogenesis in mammals is predominantly restricted to two brain regions, the dentate gyrus (DG) of the hippocampus and the olfactory bulb (OB), suggesting that these two brain regions uniquely share functions that mediate its adaptive significance. Benefits of adult neurogenesis across these two regions appear to converge on increased neuronal and structural plasticity that subserves coding of novel, complex, and fine-grained information, usually with contextual components that include spatial positioning. By contrast, costs of adult neurogenesis appear to center on potential for dysregulation resulting in higher risk of brain cancer or psychological dysfunctions, but such costs have yet to be quantified directly. The three main hypotheses for the proximate functions and adaptive significance of adult neurogenesis, pattern separation, memory consolidation, and olfactory spatial, are not mutually exclusive and can be reconciled into a simple general model amenable to targeted experimental and comparative tests. Comparative analysis of brain region sizes across two major social-ecological groups of primates, gregarious (mainly diurnal haplorhines, visually-oriented, and in large social groups) and solitary (mainly noctural, territorial, and highly reliant on olfaction, as in most rodents) suggest that solitary species, but not gregarious species, show positive associations of population densities and home range sizes with sizes of both the hippocampus and OB, implicating their functions in social-territorial systems mediated by olfactory cues. Integrated analyses of the adaptive significance of adult neurogenesis will benefit from experimental studies motivated and structured by ecologically and socially relevant selective contexts. PMID:23882188

Low acclimation capacity of narrow-ranging thermal specialists exposes susceptibility to global climate change.

PubMed

Markle, Tricia M; Kozak, Kenneth H

2018-05-01

Thermal acclimation is hypothesized to offer a selective advantage in seasonal habitats and may underlie disparities in geographic range size among closely-related species with similar ecologies. Understanding this relationship is also critical for identifying species that are more sensitive to warming climates. Here, we study North American plethodontid salamanders to investigate whether acclimation ability is associated with species' latitudinal extents and the thermal range of the environments they inhabit. We quantified variation in thermal physiology by measuring standard metabolic rate (SMR) at different test and acclimation temperatures for 16 species of salamanders with varying latitudinal extents. A phylogenetically-controlled Markov chain Monte Carlo generalized linear mixed model (MCMCglmm) was then employed to determine whether there are differences in SMR between wide- and narrow-ranging species at different acclimation temperatures. In addition, we tested for a relationship between the acclimation ability of species and the environmental temperature ranges they inhabit. Further, we investigated if there is a trade-off between critical thermal maximum (CTMax) and thermal acclimation ability. MCMCglmm results show a significant difference in acclimation ability between wide and narrow-ranging temperate salamanders. Salamanders with wide latitudinal distributions maintain or slightly increase SMR when subjected to higher test and acclimation temperatures, whereas several narrow-ranging species show significant metabolic depression. We also found significant, positive relationships between acclimation ability and environmental thermal range, and between acclimation ability and CTMax. Wide-ranging salamander species exhibit a greater capacity for thermal acclimation than narrow-ranging species, suggesting that selection for acclimation ability may have been a key factor enabling geographic expansion into areas with greater thermal variability. Further, given that narrow-ranging salamanders are found to have both poor acclimation ability and lower tolerance to warm temperatures, they are likely to be more susceptible to environmental warming associated with anthropogenic climate change.

Community-Driven Initiatives to Achieve Interoperability for Ecological and Environmental Data

NASA Astrophysics Data System (ADS)

Madin, J.; Bowers, S.; Jones, M.; Schildhauer, M.

2007-12-01

Advances in ecology and environmental science increasingly depend on information from multiple disciplines to tackle broader and more complex questions about the natural world. Such advances, however, are hindered by data heterogeneity, which impedes the ability of researchers to discover, interpret, and integrate relevant data that have been collected by others. Here, we outline two community-building initiatives for improving data interoperability in the ecological and environmental sciences, one that is well-established (the Ecological Metadata Language [EML]), and another that is actively underway (a unified model for observations and measurements). EML is a metadata specification developed for the ecology discipline, and is based on prior work done by the Ecological Society of America and associated efforts to ensure a modular and extensible framework to document ecological data. EML "modules" are designed to describe one logical part of the total metadata that should be included with any ecological dataset. EML was developed through a series of working meetings, ongoing discussion forums and email lists, with participation from a broad range of ecological and environmental scientists, as well as computer scientists and software developers. Where possible, EML adopted syntax from the other metadata standards for other disciplines (e.g., Dublin Core, Content Standard for Digital Geospatial Metadata, and more). Although EML has not yet been ratified through a standards body, it has become the de facto metadata standard for a large range of ecological data management projects, including for the Long Term Ecological Research Network, the National Center for Ecological Analysis and Synthesis, and the Ecological Society of America. The second community-building initiative is based on work through the Scientific Environment for Ecological Knowledge (SEEK) as well as a recent workshop on multi-disciplinary data management. This initiative aims at improving interoperability by describing the semantics of data at the level of observation and measurement (rather than the traditional focus at the level of the data set) and will define the necessary specifications and technologies to facilitate semantic interpretation and integration of observational data for the environmental sciences. As such, this initiative will focus on unifying the various existing approaches for representing and describing observation data (e.g., SEEK's Observation Ontology, CUAHSI's Observation Data Model, NatureServe's Observation Data Standard, to name a few). Products of this initiative will be compatible with existing standards and build upon recent advances in knowledge representation (e.g., W3C's recommended Web Ontology Language, OWL) that have demonstrated practical utility in enhancing scientific communication and data interoperability in other communities (e.g., the genomics community). A community-sanctioned, extensible, and unified model for observational data will support metadata standards such as EML while reducing the "babel" of scientific dialects that currently impede effective data integration, which will in turn provide a strong foundation for enabling cross-disciplinary synthetic research in the ecological and environmental sciences.

Temperate and tropical brown macroalgae thrive, despite decalcification, along natural CO2 gradients.

PubMed

Johnson, Vivienne R; Russell, Bayden D; Fabricius, Katharina E; Brownlee, Colin; Hall-Spencer, Jason M

2012-09-01

Predicting the impacts of ocean acidification on coastal ecosystems requires an understanding of the effects on macroalgae and their grazers, as these underpin the ecology of rocky shores. Whilst calcified coralline algae (Rhodophyta) appear to be especially vulnerable to ocean acidification, there is a lack of information concerning calcified brown algae (Phaeophyta), which are not obligate calcifiers but are still important producers of calcium carbonate and organic matter in shallow coastal waters. Here, we compare ecological shifts in subtidal rocky shore systems along CO2 gradients created by volcanic seeps in the Mediterranean and Papua New Guinea, focussing on abundant macroalgae and grazing sea urchins. In both the temperate and tropical systems the abundances of grazing sea urchins declined dramatically along CO2 gradients. Temperate and tropical species of the calcifying macroalgal genus Padina (Dictyoaceae, Phaeophyta) showed reductions in CaCO3 content with CO2 enrichment. In contrast to other studies of calcified macroalgae, however, we observed an increase in the abundance of Padina spp. in acidified conditions. Reduced sea urchin grazing pressure and significant increases in photosynthetic rates may explain the unexpected success of decalcified Padina spp. at elevated levels of CO2 . This is the first study to provide a comparison of ecological changes along CO2 gradients between temperate and tropical rocky shores. The similarities we found in the responses of Padina spp. and sea urchin abundance at several vent systems increases confidence in predictions of the ecological impacts of ocean acidification over a large geographical range. © 2012 Blackwell Publishing Ltd.

Ecological equivalency as a tool for endangered species management.

PubMed

Searcy, Christopher A; Rollins, Hilary B; Shaffer, H Bradley

2016-01-01

The use of taxon substitutes for extinct or endangered species is a controversial conservation measure. We use the example of the endangered California tiger salamander (Ambystoma californiense; CTS), which is being replaced by hybrids with the invasive barred tiger salamander (Ambystoma mavortium), to illustrate a strategy for evaluating taxon substitutes based on their position in a multivariate community space. Approximately one-quarter of CTS's range is currently occupied by "full hybrids" with 70% nonnative genes, while another one-quarter is occupied by "superinvasives" where a specific set of 3/68 genes comprising 4% of the surveyed genome is nonnative. Based on previous surveys of natural CTS breeding ponds, we stocked experimental mesocosms with field-verified, realistic densities of tiger salamander larvae and their prey, and used these mesocosms to evaluate ecological equivalency between pure CTS, full hybrids, and superinvasives in experimental pond communities. We also included a fourth treatment with no salamanders present to evaluate the community effects of eliminating Ambystoma larvae altogether. We found that pure CTS and superinvasive larvae were ecologically equivalent, because their positions in the multivariate community space were statistically indistinguishable and they did not differ significantly along any univariate community axes. Full hybrids were ecologically similar, but not equivalent, to the other two genotypes, and the no-Ambystoma treatment was by far the most divergent. We conclude that, at least for the larval stage, superinvasives are adequate taxon substitutes for pure CTS and should probably be afforded protection under the Endangered Species Act. The proper conservation status for full hybrids remains debatable.

Occurrence and Ecological Risk Assessment of Eight Endocrine-Disrupting Chemicals in Urban River Water and Sediments of South China.

PubMed

Huang, Cong; Wu, Liu-Hong; Liu, Guo-Qiang; Shi, Lei; Guo, Ying

2018-05-03

Chemicals in the water of urban areas are representative of the occurrence of these chemicals in the city surrounding water systems and reflect recent human or industrial usage of those chemicals in the sampling areas. In this study, the levels of eight endocrine-disrupting chemicals [including bisphenol analogues, parabens, and triclosan (TCS)] were determined in urban river water and sediments in Guangzhou, South China, and their related ecological risks were evaluated. The eight target chemicals were frequently detected in our samples, with concentrations ranging from not detected (ND) to 65,600 ng/L and from ND to 492 ng/g dw in river water and sediments, respectively. Among these chemicals, the three most abundant were bisphenol A (BPA) (accounting for 35% of the total amount), methyl paraben (MeP) (23%), and TCS (14%) in river water and BPA (43%), TCS (37%), and MeP (14%) in sediments. Significant correlations were found between most target EDCs, particularly MeP and TCS, in river water and sediments (both p < 0.01), indicating their similar sources and wide usage. The ecological risk assessment methods used suggested that TCS was the chemical of primary concern, with an average hazard quotient (HQ) = 1.57 (up to 11.5) in river water and an average HQ = 0.74 (up to 3.63) in sediments. In addition, the ecological risk assessment of different sampling sites indicated a suspected high-risk level for some sites in the study area.

Status and trends of selected resources in the Upper Mississippi River System

USGS Publications Warehouse

Johnson, Barry L.; Hagerty, Karen H.

2010-01-01

Like other large rivers, the Upper Mississippi River System (UMRS) serves a diversity of roles. The UMRS provides commercial and recreational fishing, floodplain agriculture, drinking water for many communities, an important bird migration pathway, a variety of recreational activities, and a navigation system that transports much of the country's agricultural exports. These multiple roles present significant management challenges. Regular assessment of the condition of the river is needed to improve management plans and evaluate their effectiveness. This report provides a summary of the recent status (mean and range of conditions) and trends (change in direction over time) for 24 indicators of the ecological condition of the Upper Mississippi and Illinois Rivers using data collected through the Long Term Resource Monitoring Program (LTRMP). The 24 indicators were grouped into seven categories: hydrology, sedimentation, water quality, land cover, aquatic vegetation, invertebrates, and fish. Most of the data used in the report were collected between about 1993 and 2004, although some older data were also used to compare to recent conditions.Historical observations and current LTRMP data clearly indicate that the UMRS has been changed by human activity in ways that have diminished the ecological health of the river. The data indicate that status and trends differ among regions, and we expect that regional responses to various ecological rehabilitation techniques will differ as well. The continuing role of the LTRMP will be to provide the data needed to assess changes in river conditions and to determine how those changes relate to management actions, natural variation, and the overall ecological integrity of the river system.

Transitions in Arctic ecosystems: Ecological implications of a changing hydrological regime

NASA Astrophysics Data System (ADS)

Wrona, Frederick J.; Johansson, Margareta; Culp, Joseph M.; Jenkins, Alan; Mârd, Johanna; Myers-Smith, Isla H.; Prowse, Terry D.; Vincent, Warwick F.; Wookey, Philip A.

2016-03-01

Numerous international scientific assessments and related articles have, during the last decade, described the observed and potential impacts of climate change as well as other related environmental stressors on Arctic ecosystems. There is increasing recognition that observed and projected changes in freshwater sources, fluxes, and storage will have profound implications for the physical, biogeochemical, biological, and ecological processes and properties of Arctic terrestrial and freshwater ecosystems. However, a significant level of uncertainty remains in relation to forecasting the impacts of an intensified hydrological regime and related cryospheric change on ecosystem structure and function. As the terrestrial and freshwater ecology component of the Arctic Freshwater Synthesis, we review these uncertainties and recommend enhanced coordinated circumpolar research and monitoring efforts to improve quantification and prediction of how an altered hydrological regime influences local, regional, and circumpolar-level responses in terrestrial and freshwater systems. Specifically, we evaluate (i) changes in ecosystem productivity; (ii) alterations in ecosystem-level biogeochemical cycling and chemical transport; (iii) altered landscapes, successional trajectories, and creation of new habitats; (iv) altered seasonality and phenological mismatches; and (v) gains or losses of species and associated trophic interactions. We emphasize the need for developing a process-based understanding of interecosystem interactions, along with improved predictive models. We recommend enhanced use of the catchment scale as an integrated unit of study, thereby more explicitly considering the physical, chemical, and ecological processes and fluxes across a full freshwater continuum in a geographic region and spatial range of hydroecological units (e.g., stream-pond-lake-river-near shore marine environments).

Predicting performance for ecological restoration: A case study using Spartina altemiflora

USGS Publications Warehouse

Travis, S.E.; Grace, J.B.

2010-01-01

The success of population-based ecological restoration relies on the growth and reproductive performance of selected donor materials, whether consisting of whole plants or seed. Accurately predicting performance requires an understanding of a variety of underlying processes, particularly gene flow and selection, which can be measured, at least in part, using surrogates such as neutral marker genetic distances and simple latitudinal effects. Here we apply a structural equation modeling approach to understanding and predicting performance in a widespread salt marsh grass, Spartina alterniflora, commonly used for ecological restoration throughout its native range in North America. We collected source materials from throughout this range, consisting of eight clones each from 23 populations, for transplantation to a common garden site in coastal Louisiana and monitored their performance. We modeled performance as a latent process described by multiple indicator variables (e.g., clone diameter, stem number) and estimated direct and indirect influences of geographic and genetic distances on performance. Genetic distances were determined by comparison of neutral molecular markers with those from a local population at the common garden site. Geographic distance metrics included dispersal distance (the minimum distance over water between donor and experimental sites) and latitude. Model results indicate direct effects of genetic distance and latitude on performance variation among the donor sites. Standardized effect strengths indicate that performance was roughly twice as sensitive to variation in genetic distance as to latitudinal variation. Dispersal distance had an indirect influence on performance through effects on genetic distance, indicating a typical pattern of genetic isolation by distance. Latitude also had an indirect effect on genetic distance through its linear relationship with dispersal distance. Three performance indicators had significant loadings on performance alone (mean clone diameter, mean number of stems, mean number of inflorescences), while the performance indicators mean stem height and mean stem width were also influenced by latitude. We suggest that dispersal distance and latitude should provide an adequate means of predicting performance in future S. alterniflora restorations and propose a maximum sampling distance of 300 km (holding latitude constant) to avoid the sampling of inappropriate ecotypes. ?? 2010 by the Ecological Society of America.

Response of selected plants to fire on white sands missile range, New Mexico

Treesearch

Kenneth G. Boykin

2008-01-01

Little was known about the ecology, impacts, effects, and history of fire related to manyplants and communities within White Sands Missile Range. I began by identifying the knownaspects and the gaps in knowledge for White Sands Missile Range. I analyzed existing dataavailable for the Installation taken from the Integrated Training...

Disturbance regimes and the historical range and variation in terrestrial ecosystems

Treesearch

Robert Keane

2017-01-01

Disturbances are major drivers of ecological dynamics and it is the cumulative effects of disturbances across space and time that define a disturbance regime and dictate biodiversity by influencing the ranges of vegetation structures, compositions, and processes on landscapes. This range and variation of landscape characteristics under historical disturbance regimes...

36 CFR 222.69 - Relocation and disposal of animals.

Code of Federal Regulations, 2013 CFR

2013-07-01

... AGRICULTURE RANGE MANAGEMENT Management of Wild Free-Roaming Horses and Burros § 222.69 Relocation and... removed so as to restore a thriving natural ecological balance to the range, and protect the range from... agent shall destroy, remove, or relocate any wild free-roaming horse or burro located on the National...

Range management research, Fort Valley Experimental Forest

Treesearch

Henry A. Pearson; Warren P. Clary; Margaret M. Moore; Carolyn Hull Sieg

2008-01-01

Range management research at the Fort Valley Experimental Forest during the past 100 years has provided scientific knowledge for managing ponderosa pine forests and forest-range grazing lands in the Southwest. Three research time periods are identified: 1908 to 1950, 1950 to 1978, and 1978 to 2008. Early research (1908-1950) addressed ecological effects of livestock...

A hierarchical framework of aquatic ecological units in North America (Nearctic Zone).

Treesearch

James R. Maxwell; Clayton J. Edwards; Mark E. Jensen; Steven J. Paustian; Harry Parrott; Donley M. Hill

1995-01-01

Proposes a framework for classifying and mapping aquatic systems at various scales using ecologically significant physical and biological criteria. Classification and mapping concepts follow tenets of hierarchical theory, pattern recognition, and driving variables. Criteria are provided for the hierarchical classification and mapping of aquatic ecological units of...

Infectious diseases of fishes in the Salish Sea

USGS Publications Warehouse

Hershberger, Paul; Rhodes, Linda; Kurath, Gael; Winton, James

2013-01-01

As in marine regions throughout other areas of the world, fishes in the Salish Sea serve as hosts for many pathogens, including nematodes, trematodes, protozoans, protists, bacteria, viruses, and crustaceans. Here, we review some of the better-documented infectious diseases that likely contribute to significant losses among free-ranging fishes in the Salish Sea and discuss the environmental and ecological factors that may affect the population-level impacts of disease. Demonstration of these diseases and their impacts to critical and endangered resources provides justification to expand pathogen surveillance efforts and to incorporate disease forecasting and mitigation tools into ecosystem restoration efforts.