Biotic and abiotic processes in eastside ecosystems: the effects of management on plant and community ecology and on stand and landscape vegetation dynamics.

Treesearch

Charles G. Johnson; Rodrick R. Clausnitzer; Peter J. Mehringer; Chadwick D. Oliver

1994-01-01

Paleo-vegetation studies have shown that vegetation has changed in composition and extent in the intermountain Pacific Northwest over the past 20,000 years. Today, both natural and human-induced disturbances have long-term influence on the structure and composition of eastside vegetation. Disturbance may enhance landscape diversity, therefore, the scale of modifying...

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

Neitzel, D.A.; McKenzie, D.H.

To minimize adverse impact on aquatic ecosystems resulting from the operation of water intake structures, design engineers must have relevant information on the behavior, physiology and ecology of local fish and shellfish. Identification of stimulus/response relationships and the environmental factors that influence them is the first step in incorporating biological information in the design, location or modification of water intake structures. A procedure is presented in this document for providing biological input to engineers who are designing, locating or modifying a water intake structure. The authors discuss sources of stimuli at water intakes, historical approaches in assessing potential/actual impact andmore » review biological information needed for intake design.« less

METHODS FOR DETERMINING EXPOSURE TO AND POTENTIAL ECOLOGICAL EFFECTS OF GENE FLOW FROM GENETICALLY MODIFIED CROPS TO COMPATIBLE RELATIVES

EPA Science Inventory

SCIENCE QUESTIONS:

-Does gene flow occur from genetically modified (GM) crop plants to compatible plants?

-How can it be measured?

-Are there ecological consequences of GM crop gene flow to plant communities?



RESEARCH:

The objectives ...

Deer herbivory reduces web-building spider abundance by simplifying forest vegetation structure

PubMed Central

Chips, Michael J.; Carson, Walter P.

2016-01-01

Indirect ecological effects are a common feature of ecological systems, arising when one species affects interactions among two or more other species. We examined how browsing by white-tailed deer (Odocoileus virginianus) indirectly affected the abundance and composition of a web-building spider guild through their effects on the structure of the ground and shrub layers of northern hardwood forests. We examined paired plots consisting of deer-free and control plots in the Allegheny Plateau region Pennsylvania and Northern Highlands region of Wisconsin. We recorded the abundance of seven types of webs, each corresponding to a family of web-building spiders. We quantified vegetation structure and habitat suitability for the spiders by computing a web scaffold availability index (WSAI) at 0.5 m and 1.0 m above the ground. At Northern Highlands sites, we recorded prey availability. Spider webs were twice as abundant in deer-free plots compared to control plots, while WSAI was 7–12 times greater in deerfree plots. Prey availability was lower in deer-free plots. With the exception of funnel web-builders, all spider web types were significantly more abundant in deer-free plots. Both deer exclusion and the geographic region of plots were significant predictors of spider community structure. In closed canopy forests with high browsing pressure, the low density of tree saplings and shrubs provides few locations for web-building spiders to anchor webs. Recruitment of these spiders may become coupled with forest disturbance events that increase tree and shrub recruitment. By modifying habitat structure, deer appear to indirectly modify arthropod food web interactions. As deer populations have increased in eastern North America over the past several decades, the effects of deer on web-building spiders may be widespread. PMID:27703868

Feedbacks between geomorphology and biota controlling Earth surface processes and landforms: A review of foundation concepts and current understandings

NASA Astrophysics Data System (ADS)

Corenblit, Dov; Baas, Andreas C. W.; Bornette, Gudrun; Darrozes, José; Delmotte, Sébastien; Francis, Robert A.; Gurnell, Angela M.; Julien, Frédéric; Naiman, Robert J.; Steiger, Johannes

2011-06-01

This review article presents recent advances in the field of biogeomorphology related to the reciprocal coupling between Earth surface processes and landforms, and ecological and evolutionary processes. The aim is to present to the Earth Science community ecological and evolutionary concepts and associated recent conceptual developments for linking geomorphology and biota. The novelty of the proposed perspective is that (1) in the presence of geomorphologic-engineer species, which modify sediment and landform dynamics, natural selection operating at the scale of organisms may have consequences for the physical components of ecosystems, and particularly Earth surface processes and landforms; and (2) in return, these modifications of geomorphologic processes and landforms often feed back to the ecological characteristics of the ecosystem (structure and function) and thus to biological characteristics of engineer species and/or other species (adaptation and speciation). The main foundation concepts from ecology and evolutionary biology which have led only recently to an improved conception of landform dynamics in geomorphology are reviewed and discussed. The biogeomorphologic macroevolutionary insights proposed explicitly integrate geomorphologic niche-dimensions and processes within an ecosystem framework and reflect current theories of eco-evolutionary and ecological processes. Collectively, these lead to the definition of an integrated model describing the overall functioning of biogeomorphologic systems over ecological and evolutionary timescales.

Direct and indirect effects of multiple stressors on stream invertebrates across watershed, reach and site scales: A structural equation modelling better informing on hydromorphological impacts.

PubMed

Villeneuve, B; Piffady, J; Valette, L; Souchon, Y; Usseglio-Polatera, P

2018-01-15

The purpose of our approach was to take into account the nested spatial scales driving stream functioning in the description of pressures/ecological status links by analysing the results of a hierarchical model. The development of this model has allowed us to answer the following questions: Does the consideration of the indirect links between anthropogenic pressures and stream ecological status modify the hierarchy of pressure types impacting benthic invertebrates? Do the different nested scales play different roles in the anthropogenic pressures/ecological status relationship? Does this model lead to better understanding of the specific role of hydromorphology in the evaluation of stream ecological status? To achieve that goal, we used the Partial Least Square (PLS) path modelling method to develop a structural model linking variables describing (i) land use and hydromorphological alterations at the watershed scale, (ii) hydromorphological alterations at the reach scale, (iii) nutrients-organic matter contamination levels at the site scale, and (iv) substrate characteristics at the sampling site scale, to explain variation in values of a macroinvertebrate-based multimetric index: the French I 2 M 2 . We have highlighted the importance of land use effects exerted on both hydromorphological and chemical characteristics of streams observed at finer scales and their subsequent indirect impact on stream ecological status. Hydromorphological alterations have an effect on the substrate mosaic structure and on the concentrations of nutrients and organic matter at site scale. This result implies that stream hydromorphology can have a major indirect effect on macroinvertebrate assemblages and that the hierarchy of impacts of anthropogenic pressures on stream ecological status generally described in the literature - often determining strategic restoration priorities - has to be re-examined. Finally, the effects of nutrients and organic matter on macroinvertebrate assemblages are lower than expected when all the indirect effects of land use and hydromorphological alterations are taken into account. Copyright © 2017 Elsevier B.V. All rights reserved.

Ecological consequences of forest elephant declines for Afrotropical forests.

PubMed

Poulsen, John R; Rosin, Cooper; Meier, Amelia; Mills, Emily; Nuñez, Chase L; Koerner, Sally E; Blanchard, Emily; Callejas, Jennifer; Moore, Sarah; Sowers, Mark

2018-06-01

Poaching is rapidly extirpating African forest elephants (Loxodonta cyclotis) from most of their historical range, leaving vast areas of elephant-free tropical forest. Elephants are ecological engineers that create and maintain forest habitat; thus, their loss will have large consequences for the composition and structure of Afrotropical forests. Through a comprehensive literature review, we evaluated the roles of forest elephants in seed dispersal, nutrient recycling, and herbivory and physical damage to predict the cascading ecological effects of their population declines. Loss of seed dispersal by elephants will favor tree species dispersed abiotically and by smaller dispersal agents, and tree species composition will depend on the downstream effects of changes in elephant nutrient cycling and browsing. Loss of trampling and herbivory of seedlings and saplings will result in high tree density with release from browsing pressures. Diminished seed dispersal by elephants and high stem density are likely to reduce the recruitment of large trees and thus increase homogeneity of forest structure and decrease carbon stocks. The loss of ecological services by forest elephants likely means Central African forests will be more like Neotropical forests, from which megafauna were extirpated thousands of years ago. Without intervention, as much as 96% of Central African forests will have modified species composition and structure as elephants are compressed into remaining protected areas. Stopping elephant poaching is an urgent first step to mitigating these effects, but long-term conservation will require land-use planning that incorporates elephant habitat into forested landscapes that are being rapidly transformed by industrial agriculture and logging. © 2017 Society for Conservation Biology.

Size structure of marine soft-bottom macrobenthic communities across natural habitat gradients: implications for productivity and ecosystem function.

PubMed

Macdonald, Tara A; Burd, Brenda J; van Roodselaar, Albert

2012-01-01

Size distributions of biotic assemblages are important modifiers of productivity and function in marine sediments. We investigated the distribution of proportional organic biomass among logarithmic size classes (2(-6)J to 2(16)J) in the soft-bottom macrofaunal communities of the Strait of Georgia, Salish Sea on the west coast of Canada. The study examines how size structure is influenced by 3 fundamental habitat descriptors: depth, sediment percent fines, and organic flux (modified by quality). These habitat variables are uncorrelated in this hydrographically diverse area, thus we examine their effects in combination and separately. Cluster analyses and cumulative biomass size spectra reveal clear and significant responses to each separate habitat variable. When combined, habitat factors result in three distinct assemblages: (1) communities with a high proportion of biomass in small organisms, typical of shallow areas (<10 m) with coarse sediments (<10% fines) and low accumulation of organic material (<3.0 gC/m(2)/yr/δ(15)N); (2) communities with high proportion of biomass in the largest organisms found in the Strait, typical of deep, fine sediments with high modified organic flux (>3 g C/m(2)/yr/δ(15)N) from the Fraser River; and (3) communities with biomass dominated by moderately large organisms, but lacking the smallest and largest size classes, typical of deep, fine sediments experiencing low modified organic flux (<3.0 gC/m(2)/yr/δ(15)N). The remaining assemblages had intermediate habitat types and size structures. Sediment percent fines and flux appear to elicit threshold responses in size structure, whereas depth has the most linear influence on community size structure. The ecological implications of size structure in the Strait of Georgia relative to environmental conditions, secondary production and sediment bioturbation are discussed.

Size Structure of Marine Soft-Bottom Macrobenthic Communities across Natural Habitat Gradients: Implications for Productivity and Ecosystem Function

PubMed Central

Macdonald, Tara A.; Burd, Brenda J.; van Roodselaar, Albert

2012-01-01

Size distributions of biotic assemblages are important modifiers of productivity and function in marine sediments. We investigated the distribution of proportional organic biomass among logarithmic size classes (2−6J to 216J) in the soft-bottom macrofaunal communities of the Strait of Georgia, Salish Sea on the west coast of Canada. The study examines how size structure is influenced by 3 fundamental habitat descriptors: depth, sediment percent fines, and organic flux (modified by quality). These habitat variables are uncorrelated in this hydrographically diverse area, thus we examine their effects in combination and separately. Cluster analyses and cumulative biomass size spectra reveal clear and significant responses to each separate habitat variable. When combined, habitat factors result in three distinct assemblages: (1) communities with a high proportion of biomass in small organisms, typical of shallow areas (<10 m) with coarse sediments (<10% fines) and low accumulation of organic material (<3.0 gC/m2/yr/δ15N); (2) communities with high proportion of biomass in the largest organisms found in the Strait, typical of deep, fine sediments with high modified organic flux (>3 g C/m2/yr/δ15N) from the Fraser River; and (3) communities with biomass dominated by moderately large organisms, but lacking the smallest and largest size classes, typical of deep, fine sediments experiencing low modified organic flux (<3.0 gC/m2/yr/δ15N). The remaining assemblages had intermediate habitat types and size structures. Sediment percent fines and flux appear to elicit threshold responses in size structure, whereas depth has the most linear influence on community size structure. The ecological implications of size structure in the Strait of Georgia relative to environmental conditions, secondary production and sediment bioturbation are discussed. PMID:22911694

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.

Measuring Children's Environmental Attitudes and Values in Northwest Mexico: Validating a Modified Version of Measures to Test the Model of Ecological Values (2-MEV)

ERIC Educational Resources Information Center

Schneller, A. J.; Johnson, B.; Bogner, F. X.

2015-01-01

This paper describes the validation process of measuring children's attitudes and values toward the environment within a Mexican sample. We applied the Model of Ecological Values (2-MEV), which has been shown to be valid and reliable in 20 countries, including one Spanish speaking culture. Items were initially modified to fit the regional dialect,…

Assessing Anthropogenic Influence and Edge Effect Influence on Forested Riparian Buffer Spatial Configuration and Structure: An Example Using Lidar Remote Sensing Methods

NASA Astrophysics Data System (ADS)

Wasser, L. A.; Chasmer, L. E.

2012-12-01

Forested riparian buffers (FRB) perform numerous critical ecosystem services. However, globally, FRB spatial configuration and structure have been modified by anthropogenic development resulting in widespread ecological degradation as seen in the Gulf of Mexico and the Chesapeake Bay. Riparian corridors within developed areas are particularly vulnerable to disturbance given two edges - the naturally occurring stream edge and the matrix edge. Increased edge length predisposes riparian vegetation to "edge effects", characterized by modified physical and environmental conditions at the interface between the forested buffer and the adjacent landuse, or matrix and forest fragment degradation. The magnitude and distance of edge influence may be further influenced by adjacent landuse type and the width of the buffer corridor at any given location. There is a need to quantify riparian buffer spatial configuration and structure over broad geographic extents and within multiple riparian systems in support of ecologically sound management and landuse decisions. This study thus assesses the influence of varying landuse types (agriculture, suburban development and undeveloped) on forested riparian buffer 3-dimensional structure and spatial configuration using high resolution Light Detection and Ranging (LiDAR) data collected within a headwater watershed. Few studies have assessed riparian buffer structure and width contiguously for an entire watershed, an integral component of watershed planning and restoration efforts such as those conducted throughout the Chesapeake Bay. The objectives of the study are to 1) quantify differences in vegetation structure at the stream and matrix influenced riparian buffer edges, compared to the forested interior and 2) assess continuous patterns of changes in vegetation structure throughout the buffer corridor beginning at the matrix edge and ending at the stream within buffers a) of varying width and b) that are adjacent to varying landuse types. Results suggest that 1) the spatial configuration of riparian forests has a strong influence on forest structure compared to a weaker association with adjacent landuse type 2) developed landuse types are often associated with increased understory vegetation density 3) that riparian vegetation canopy cover is dense regardless of corridor width or adjacent landuse type and 4) the degree to which edge effects propagate into the buffer corridor is most influenced by corridor width. The study further demonstrates the utility of automated algorithms that sample lidar data in watershed-wide ecological analysis. Results suggest that landuse regulations should encourage wider buffers which will in turn support a greater range of ecosystem services including improved wildlife habitat, stream shading and detrital inputs.

Rare ecomorphological convergence on a complex adaptive landscape: Body size and diet mediate evolution of jaw shape in squirrels (Sciuridae).

PubMed

Zelditch, Miriam Leah; Ye, Ji; Mitchell, Jonathan S; Swiderski, Donald L

2017-03-01

Convergence is widely regarded as compelling evidence for adaptation, often being portrayed as evidence that phenotypic outcomes are predictable from ecology, overriding contingencies of history. However, repeated outcomes may be very rare unless adaptive landscapes are simple, structured by strong ecological and functional constraints. One such constraint may be a limitation on body size because performance often scales with size, allowing species to adapt to challenging functions by modifying only size. When size is constrained, species might adapt by changing shape; convergent shapes may therefore be common when size is limiting and functions are challenging. We examine the roles of size and diet as determinants of jaw shape in Sciuridae. As expected, size and diet have significant interdependent effects on jaw shape and ecomorphological convergence is rare, typically involving demanding diets and limiting sizes. More surprising is morphological without ecological convergence, which is equally common between and within dietary classes. Those cases, like rare ecomorphological convergence, may be consequences of evolving on an adaptive landscape shaped by many-to-many relationships between ecology and function, many-to-one relationships between form and performance, and one-to-many relationships between functionally versatile morphologies and ecology. On complex adaptive landscapes, ecological selection can yield different outcomes. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

Disrupting the Networks of Cancer

PubMed Central

Camacho, Daniel F.; Pienta, Kenneth J.

2014-01-01

Ecosystems are interactive systems involving communities of species and their abiotic environment. Tumors are ecosystems in which cancer cells act as invasive species interacting with native host cell species in an established microenvironment within the larger host biosphere. At its heart, to study ecology is to study interconnectedness. In ecologic science, an ecologic network is a representation of the biotic interactions in an ecosystem in which species (nodes) are connected by pairwise interactions (links). Ecologic networks and signaling network models have been used to describe and compare the structures of ecosystems. It has been shown that disruption of ecologic networks through the loss of species or disruption of interactions between them can lead to the destruction of the ecosystem. Often, the destruction of a single node or link is not enough to disrupt the entire ecosystem. The more complex the network and its interactions, the more difficult it is to cause the extinction of a species, especially without leveraging other aspects of the ecosystem. Similarly, successful treatment of cancer with a single agent is rarely enough to cure a patient without strategically modifying the support systems conducive to survival of cancer. Cancer cells and the ecologic systems they reside in can be viewed as a series of nested networks. The most effective new paradigms for treatment will be developed through application of scaled network disruption. PMID:22442061

Disrupting the networks of cancer.

PubMed

Camacho, Daniel F; Pienta, Kenneth J

2012-05-15

Ecosystems are interactive systems involving communities of species and their abiotic environment. Tumors are ecosystems in which cancer cells act as invasive species interacting with native host cell species in an established microenvironment within the larger host biosphere. At its heart, to study ecology is to study interconnectedness. In ecologic science, an ecologic network is a representation of the biotic interactions in an ecosystem in which species (nodes) are connected by pairwise interactions (links). Ecologic networks and signaling network models have been used to describe and compare the structures of ecosystems. It has been shown that disruption of ecologic networks through the loss of species or disruption of interactions between them can lead to the destruction of the ecosystem. Often, the destruction of a single node or link is not enough to disrupt the entire ecosystem. The more complex the network and its interactions, the more difficult it is to cause the extinction of a species, especially without leveraging other aspects of the ecosystem. Similarly, successful treatment of cancer with a single agent is rarely enough to cure a patient without strategically modifying the support systems conducive to survival of cancer. Cancer cells and the ecologic systems they reside in can be viewed as a series of nested networks. The most effective new paradigms for treatment will be developed through application of scaled network disruption. ©2012 AACR.

Revisiting the ants of Melanesia and the taxon cycle: historical and human-mediated invasions of a tropical archipelago.

PubMed

Economo, Evan P; Sarnat, Eli M

2012-07-01

Understanding the historical evolution of biotas and the dynamics of contemporary human-mediated species introductions are two central tasks of biology. One hypothesis may address both-the taxon cycle. Taxon cycles are phases of range expansion and contraction coupled to ecological and evolutionary niche shifts. These historical invasion processes resemble human-mediated invasions in pattern and possibly mechanism, but both the existence of historical cycles and the roles of recent introductions are in question. We return to the system that originally inspired the taxon cycle-Melanesian ants-and perform novel tests of the hypothesis. We analyze (i) the habitat distributions of Fiji's entire ant fauna (183 species), (ii) ecological shifts associated with the in situ radiation of Fijian Pheidole in a phylogenetic context, and (iii) the ecological structure of a massive exotic ant invasion of the archipelago. Our analyses indicate lineages shift toward primary habitats, higher elevation, rarity, and ecological specialization with increasing level of endemism, consistent with taxon cycle predictions. The marginal habitats that historically formed a dispersal conduit in the Pacific are now mostly replaced by human-modified habitats dominated by a colonization pulse of exotic species. We propose this may represent the first phase of an incipient global cycle of human-mediated colonization, ecological shifts, and diversification.

The Genus Cladophora Kützing (Ulvophyceae) as a Globally Distributed Ecological Engineer.

PubMed

Zulkifly, Shahrizim B; Graham, James M; Young, Erica B; Mayer, Robert J; Piotrowski, Michael J; Smith, Izak; Graham, Linda E

2013-02-01

The green algal genus Cladophora forms conspicuous nearshore populations in marine and freshwaters worldwide, commonly dominating peri-phyton communities. As the result of human activities, including the nutrient pollution of nearshore waters, Cladophora-dominated periphyton can form nuisance blooms. On the other hand, Cladophora has ecological functions that are beneficial, but less well appreciated. For example, Cladophora has previously been characterized as an ecological engineer because its complex structure fosters functional and taxonomic diversity of benthic microfauna. Here, we review classic and recent literature concerning taxonomy, cell biology, morphology, reproductive biology, and ecology of the genus Cladophora, to examine how this alga functions to modify habitats and influence littoral biogeochemistry. We review the evidence that Cladophora supports large, diverse populations of microalgal and bacterial epiphytes that influence the cycling of carbon and other key elements, and that the high production of cellulose and hydrocarbons by Cladophora-dominated periphyton has the potential for diverse technological applications, including wastewater remediation coupled to renewable biofuel production. We postulate that well-known aspects of Cladophora morphology, hydrodynamically stable and perennial holdfasts, distinctively branched architecture, unusually large cell and sporangial size and robust cell wall construction, are major factors contributing to the multiple roles of this organism as an ecological engineer. © 2013 Phycological Society of America.

Use of prescribed burning for restoration and maintenance of ecological conditions: Predicting and managing fire injury and tree mortality

Treesearch

Kevin Ryan; E. Rigolot; F. C. Rego; H. Botelho; J. A. Vega; P. M. Fernandes; T. M. Sofronova

2010-01-01

Throughout Earth’s history fire has been a major disturbance factor in many terrestrial ecosystems. Fire is man’s first tool. It was used for a host of cultural purposes to modify stand structure and species composition as well as landscape pattern and process. Changes in climate and land use are leading to changes in vegetation and the frequency and severity of modern...

Cement and Concrete Nanoscience and Nanotechnology

PubMed Central

Raki, Laila; Beaudoin, James; Alizadeh, Rouhollah; Makar, Jon; Sato, Taijiro

2010-01-01

Concrete science is a multidisciplinary area of research where nanotechnology potentially offers the opportunity to enhance the understanding of concrete behavior, to engineer its properties and to lower production and ecological cost of construction materials. Recent work at the National Research Council Canada in the area of concrete materials research has shown the potential of improving concrete properties by modifying the structure of cement hydrates, addition of nanoparticles and nanotubes and controlling the delivery of admixtures. This article will focus on a review of these innovative achievements.

Systematic Representation of Knowledge of Ecology: Concepts and Relationships.

ERIC Educational Resources Information Center

Garb, Yaakov; And Others

This study describes efforts to apply principles of systematic knowledge representation (concept mapping and computer-based semantic networking techniques) to the domain of ecology. A set of 24 relationships and modifiers is presented that seem sufficient for describing all ecological relationships discussed in an introductory course. Many of…

Restoration treatments in urban park forests drive long-term changes in vegetation trajectories.

PubMed

Johnson, Lea R; Handel, Steven N

2016-04-01

Municipalities are turning to ecological restoration of urban forests as a measure to improve air quality, ameliorate urban heat island effects, improve storm water infiltration, and provide other social and ecological benefits. However, community dynamics following urban forest restoration treatments are poorly documented. This study examines the long-term effects of ecological restoration undertaken in New York City, New York, USA, to restore native forest in urban park natural areas invaded by woody non-native plants that are regional problems. In 2009 and 2010, we sampled vegetation in 30 invaded sites in three large public parks that were restored 1988-1993, and 30 sites in three large parks that were similarly invaded but had not been restored. Data from these matched plots reveal that the restoration treatment achieved its central goals. After 15-20 years, invasive species removal followed by native tree planting resulted in persistent structural and compositional shifts, significantly lower invasive species abundance, a more complex forest structure, and greater native tree recruitment. Together, these findings indicate that successional trajectories of vegetation dynamics have diverged between restored forests and invaded forests that were not restored. In addition, the data suggest that future composition of these urban forest patches will be novel assemblages. Restored and untreated sites shared a suite of shade-intolerant, quickly-growing tree species that colonize disturbed sites, indicating that restoration treatments created sites hospitable for germination and growth of species adapted to high light conditions and disturbed soils. These findings yield an urban perspective on the use of succession theory in ecological restoration. Models of ecological restoration developed in more pristine environments must be modified for use in cities. By anticipating both urban disturbances and ecological succession, management of urban forest patches can be adjusted to better predict and direct long-term outcomes. An urban approach to ecological restoration must use realistic, flexible targets to preserve and enhance urban biodiversity for both short-term benefits and long-term sustainability.

Fish Assemblages Associated with Natural and Anthropogenically-Modified Habitats in a Marine Embayment: Comparison of Baited Videos and Opera-House Traps

PubMed Central

Wakefield, Corey B.; Lewis, Paul D.; Coutts, Teresa B.; Fairclough, David V.; Langlois, Timothy J.

2013-01-01

Marine embayments and estuaries play an important role in the ecology and life history of many fish species. Cockburn Sound is one of a relative paucity of marine embayments on the west coast of Australia. Its sheltered waters and close proximity to a capital city have resulted in anthropogenic intrusion and extensive seascape modification. This study aimed to compare the sampling efficiencies of baited videos and fish traps in determining the relative abundance and diversity of temperate demersal fish species associated with naturally occurring (seagrass, limestone outcrops and soft sediment) and modified (rockwall and dredge channel) habitats in Cockburn Sound. Baited videos sampled a greater range of species in higher total and mean abundances than fish traps. This larger amount of data collected by baited videos allowed for greater discrimination of fish assemblages between habitats. The markedly higher diversity and abundances of fish associated with seagrass and limestone outcrops, and the fact that these habitats are very limited within Cockburn Sound, suggests they play an important role in the fish ecology of this embayment. Fish assemblages associated with modified habitats comprised a subset of species in lower abundances when compared to natural habitats with similar physical characteristics. This suggests modified habitats may not have provided the necessary resource requirements (e.g. shelter and/or diet) for some species, resulting in alterations to the natural trophic structure and interspecific interactions. Baited videos provided a more efficient and non-extractive method for comparing fish assemblages and habitat associations of smaller bodied species and juveniles in a turbid environment. PMID:23555847

Fish assemblages associated with natural and anthropogenically-modified habitats in a marine embayment: comparison of baited videos and opera-house traps.

PubMed

Wakefield, Corey B; Lewis, Paul D; Coutts, Teresa B; Fairclough, David V; Langlois, Timothy J

2013-01-01

Marine embayments and estuaries play an important role in the ecology and life history of many fish species. Cockburn Sound is one of a relative paucity of marine embayments on the west coast of Australia. Its sheltered waters and close proximity to a capital city have resulted in anthropogenic intrusion and extensive seascape modification. This study aimed to compare the sampling efficiencies of baited videos and fish traps in determining the relative abundance and diversity of temperate demersal fish species associated with naturally occurring (seagrass, limestone outcrops and soft sediment) and modified (rockwall and dredge channel) habitats in Cockburn Sound. Baited videos sampled a greater range of species in higher total and mean abundances than fish traps. This larger amount of data collected by baited videos allowed for greater discrimination of fish assemblages between habitats. The markedly higher diversity and abundances of fish associated with seagrass and limestone outcrops, and the fact that these habitats are very limited within Cockburn Sound, suggests they play an important role in the fish ecology of this embayment. Fish assemblages associated with modified habitats comprised a subset of species in lower abundances when compared to natural habitats with similar physical characteristics. This suggests modified habitats may not have provided the necessary resource requirements (e.g. shelter and/or diet) for some species, resulting in alterations to the natural trophic structure and interspecific interactions. Baited videos provided a more efficient and non-extractive method for comparing fish assemblages and habitat associations of smaller bodied species and juveniles in a turbid environment.

The gravity of pollination: integrating at-site features into spatial analysis of contemporary pollen movement.

PubMed

DiLeo, Michelle F; Siu, Jenna C; Rhodes, Matthew K; López-Villalobos, Adriana; Redwine, Angela; Ksiazek, Kelly; Dyer, Rodney J

2014-08-01

Pollen-mediated gene flow is a major driver of spatial genetic structure in plant populations. Both individual plant characteristics and site-specific features of the landscape can modify the perceived attractiveness of plants to their pollinators and thus play an important role in shaping spatial genetic variation. Most studies of landscape-level genetic connectivity in plants have focused on the effects of interindividual distance using spatial and increasingly ecological separation, yet have not incorporated individual plant characteristics or other at-site ecological variables. Using spatially explicit simulations, we first tested the extent to which the inclusion of at-site variables influencing local pollination success improved the statistical characterization of genetic connectivity based upon examination of pollen pool genetic structure. The addition of at-site characteristics provided better models than those that only considered interindividual spatial distance (e.g. IBD). Models parameterized using conditional genetic covariance (e.g. population graphs) also outperformed those assuming panmixia. In a natural population of Cornus florida L. (Cornaceae), we showed that the addition of at-site characteristics (clumping of primary canopy opening above each maternal tree and maternal tree floral output) provided significantly better models describing gene flow than models including only between-site spatial (IBD) and ecological (isolation by resistance) variables. Overall, our results show that including interindividual and local ecological variation greatly aids in characterizing landscape-level measures of contemporary gene flow. © 2014 John Wiley & Sons Ltd.

Ecology and Ethics: Some Relationships for Nature Conservation

NASA Astrophysics Data System (ADS)

Abedi-Sarvestani, Ahmad; Shahvali, Mansoor

These days, the reality of environmental crises creates grave doubts about the future of the natural environment. Many believe that if present human behavior toward the natural environment continues, there will be no hope for a sustainable life. Therefore, it is vital that human behavior toward nature be modified and corrected. Although, ethic is traditionally concerned about relations between individuals, but it is getting more attention for modifying human behavior in order to correct human-nature interaction and establish a well-intentioned one. In this respect, we need science of ecology and ethics together. Ecology helps us to understand natural ecosystems and respective regulations and laws, whereas ethics teach us how to define right and wrong behaviors toward the natural environment. This research discusses some possible relationships that might exist between ecology and ethics toward nature conservation.

Achieving Closure for Bioregenerative Life Support Systems: Engineering and Ecological Challenges, Research Opportunities

NASA Astrophysics Data System (ADS)

Dempster, William; Allen, John P.

Closed systems are desirable for a number of purposes: space life support systems where precious life-supporting resources need to be kept inside; biospheric systems; where global ecological pro-cesses can be studied in great detail and testbeds where research topics requiring isolation from the outside (e.g. genetically modified organisms; radioisotopes) can be studied in isolation from the outside environment and where their ecological interactions and fluxes can be studied. But to achieve and maintain closure raises both engineering and ecological challenges. Engineering challenges include methods of achieving closure for structures of different materials, and devel-oping methods of allowing energy (for heating and cooling) and information transfer through the materially closed structure. Methods of calculating degree of closure include measuring degradation rates of inert trace gases introduced into the system. An allied problem is devel-oping means of locating where leaks are located so that they may be repaired and degree of closure maintained. Once closure is achieved, methods of dealing with the pressure differen-tials between inside and outside are needed: from inflatable structures which might adjust to the pressure difference to variable volume chambers attached to the life systems component. These issues are illustrated through the engineering employed at Biosphere 2, the Biosphere 2 Test Module and the Laboratory Biosphere and a discussion of methods used by other closed ecological system facility engineers. Ecological challenges include being able to handle faster cycling rates and accentuated daily and seasonal fluxes of critical life elements such as carbon dioxide, oxygen, water, macro-and mico-nutrients. The problems of achieving sustainability in closed systems for life support include how to handle atmospheric dynamics including trace gases, producing a complete human diet and recycling nutrients and maintaining soil fertility, healthy air and water and preventing the loss of crucial elements from active circulation. In biospheric facilities the challenge is also to produce analogue to natural biomes and ecosys-tems, studying processes of self-organization and adaptation in systems that allow specification or determination of state variables and cycles which may be followed through all interactions from atmosphere to soils.

[Applied ecology: retrospect and prospect].

PubMed

He, Xingyuan; Zeng, Dehui

2004-10-01

Applied ecology is evolved into a principal part of modern ecology that rapidly develops. The major stimulus for the development of applied ecology roots in seeking the solutions for the problems of human populations, resources and environments. Through four decades, the science of applied ecology has been becoming a huge group of disciplines. The future for the applied ecology should concern more with human-influenced and managed ecosystems, and acknowledge humans as the components of ecosystems. Nowadays and in future, the top-priorities in applied ecology should include following fields: sustainable ecosystems and biosphere, ecosystem services and ecological design, ecological assessment of genetically modified organisms, ecology of biological invasions, epidemical ecology, ecological forecasting, ecological process and its control. The authors believe that the comprehensive and active research hotspots coupled some new traits would occur around these fields in foreseeable future.

Yellowstone wolves and the forces that structure natural systems.

PubMed

Dobson, Andy P

2014-12-01

Since their introduction in 1995 and 1996, wolves have had effects on Yellowstone that ripple across the entire structure of the food web that defines biodiversity in the Northern Rockies ecosystem. Ecological interpretations of the wolves have generated a significant amount of debate about the relative strength of top-down versus bottom-up forces in determining herbivore and vegetation abundance in Yellowstone. Debates such as this are central to the resolution of broader debates about the role of natural enemies and climate as forces that structure food webs and modify ecosystem function. Ecologists need to significantly raise the profile of these discussions; understanding the forces that structure food webs and determine species abundance and the supply of ecosystem services is one of the central scientific questions for this century; its complexity will require new minds, new mathematics, and significant, consistent funding.

HYBRIDIZATION STUDY BETWEEN GENETICALLY MODIFIED BRASSICA NAPUS AND NON-GENETICALLY MODIFIED B. NAPUS AND B. RAPA

EPA Science Inventory

Gene exchange between cultivated crops and wild species has gained significance in recent years because of concerns regarding the potential for gene flow between genetically modified (GM) crops and their domesticated and wild relatives. As part of our ecological effects of gene ...

Hydrogeological controls on spatial patterns of groundwater discharge in peatlands

NASA Astrophysics Data System (ADS)

Hare, Danielle K.; Boutt, David F.; Clement, William P.; Hatch, Christine E.; Davenport, Glorianna; Hackman, Alex

2017-11-01

Peatland environments provide important ecosystem services including water and carbon storage, nutrient processing and retention, and wildlife habitat. However, these systems and the services they provide have been degraded through historical anthropogenic agricultural conversion and dewatering practices. Effective wetland restoration requires incorporating site hydrology and understanding groundwater discharge spatial patterns. Groundwater discharge maintains wetland ecosystems by providing relatively stable hydrologic conditions, nutrient inputs, and thermal buffering important for ecological structure and function; however, a comprehensive site-specific evaluation is rarely feasible for such resource-constrained projects. An improved process-based understanding of groundwater discharge in peatlands may help guide ecological restoration design without the need for invasive methodologies and detailed site-specific investigation. Here we examine a kettle-hole peatland in southeast Massachusetts historically modified for commercial cranberry farming. During the time of our investigation, a large process-based ecological restoration project was in the assessment and design phases. To gain insight into the drivers of site hydrology, we evaluated the spatial patterning of groundwater discharge and the subsurface structure of the peatland complex using heat-tracing methods and ground-penetrating radar. Our results illustrate that two groundwater discharge processes contribute to the peatland hydrologic system: diffuse lower-flux marginal matrix seepage and discrete higher-flux preferential-flow-path seepage. Both types of groundwater discharge develop through interactions with subsurface peatland basin structure, often where the basin slope is at a high angle to the regional groundwater gradient. These field observations indicate strong correlation between subsurface structures and surficial groundwater discharge. Understanding these general patterns may allow resource managers to more efficiently predict and locate groundwater seepage, confirm these using remote sensing technologies, and incorporate this information into restoration design for these critical ecosystems.

Development and application of a density dependent matrix ...

EPA Pesticide Factsheets

Ranging along the Atlantic coast from US Florida to the Maritime Provinces of Canada, the Atlantic killifish (Fundulus heteroclitus) is an important and well-studied model organism for understanding the effects of pollutants and other stressors in estuarine and marine ecosystems. Matrix population models are useful tools for ecological risk assessment because they integrate effects across the life cycle, provide a linkage between endpoints observed in the individual and ecological risk to the population as a whole, and project outcomes for many generations in the future. We developed a density dependent matrix population model for Atlantic killifish by modifying a model developed for fathead minnow (Pimephales promelas) that has proved to be extremely useful, e.g. to incorporate data from laboratory studies and project effects of endocrine disrupting chemicals. We developed a size-structured model (as opposed to one that is based upon developmental stages or age class structure) so that we could readily incorporate output from a Dynamic Energy Budget (DEB) model, currently under development. Due to a lack of sufficient data to accurately define killifish responses to density dependence, we tested a number of scenarios realistic for other fish species in order to demonstrate the outcome of including this ecologically important factor. We applied the model using published data for killifish exposed to dioxin-like compounds, and compared our results to those using

Rangeland health attributes and indicators for qualitative assessment

USGS Publications Warehouse

Pyke, David A.; Herrick, J.E.; Pellant, Mike

2002-01-01

Panels of experts from the Society for Range Management and the National Research Council proposed that status of rangeland ecosystems could be ascertained by evaluating an ecological site's potential to conserve soil resources and by a series of indicators for ecosystem processes and site stability. Using these recommendations as a starting point, we developed a rapid, qualitative method for assessing a moment-in-time status of rangelands. Evaluators rate 17 indicators to assess 3 ecosystem attributes (soil and site stability, hydrologic function, and biotic integrity) for a given location. Indicators include rills, water flow patterns, pedestals and terracettes, bare ground, gullies, wind scour and depositional areas, litter movement, soil resistance to erosion, soil surface loss or degradation, plant composition relative to infiltration, soil compaction, plant functional/structural groups, plant mortality, litter amount, annual production, invasive plants, and reproductive capability. In this paper, we detail the development and evolution of the technique and introduce a modified ecological reference worksheet that documents the expected presence and amount of each indicator on the ecological site. In addition, we review the intended applications for this technique and clarify the differences between assessment and monitoring that lead us to recommend this technique be used for moment-in-time assessments and not be used for temporal monitoring of rangeland status. Lastly, we propose a mechanism for adapting and modifying this technique to reflect improvements in understanding of ecosystem processes. We support the need for quantitative measures for monitoring rangeland health and propose some measures that we believe may address some of the 17 indicators.

Environmental Control on Microbial Turnover of Leaf Carbon in Streams – Ecological Function of Phototrophic-Heterotrophic Interactions

PubMed Central

Fabian, Jenny; Zlatanović, Sanja; Mutz, Michael; Grossart, Hans-Peter; van Geldern, Robert; Ulrich, Andreas; Gleixner, Gerd; Premke, Katrin

2018-01-01

In aquatic ecosystems, light availability can significantly influence microbial turnover of terrestrial organic matter through associated metabolic interactions between phototrophic and heterotrophic communities. However, particularly in streams, microbial functions vary significantly with the structure of the streambed, that is the distribution and spatial arrangement of sediment grains in the streambed. It is therefore essential to elucidate how environmental factors synergistically define the microbial turnover of terrestrial organic matter in order to better understand the ecological role of photo-heterotrophic interactions in stream ecosystem processes. In outdoor experimental streams, we examined how the structure of streambeds modifies the influence of light availability on microbial turnover of leaf carbon (C). Furthermore, we investigated whether the studied relationships of microbial leaf C turnover to environmental conditions are affected by flow intermittency commonly occurring in streams. We applied leaves enriched with a 13C-stable isotope tracer and combined quantitative and isotope analyses. We thereby elucidated whether treatment induced changes in C turnover were associated with altered use of leaf C within the microbial food web. Moreover, isotope analyses were combined with measurements of microbial community composition to determine whether changes in community function were associated with a change in community composition. In this study, we present evidence, that environmental factors interactively determine how phototrophs and heterotrophs contribute to leaf C turnover. Light availability promoted the utilization of leaf C within the microbial food web, which was likely associated with a promoted availability of highly bioavailable metabolites of phototrophic origin. However, our results additionally confirm that the structure of the streambed modifies light-related changes in microbial C turnover. From our observations, we conclude that the streambed structure influences the strength of photo-heterotrophic interactions by defining the spatial availability of algal metabolites in the streambed and the composition of microbial communities. Collectively, our multifactorial approach provides valuable insights into environmental controls on the functioning of stream ecosystems.

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.

Geography, ecology and emerging infectious diseases.

PubMed

Mayer, J D

2000-04-01

Emerging infectious diseases are the focus of increased attention and even alarm in the scholarly and popular literature. The emergence of new diseases and the resurgence of older and previously recognized infectious diseases both in developing and developed country poses challenges for understanding the ecological web of causation, including social, economic, environmental and biological components. This paper is a synthesis of the major characteristics of emerging diseases, in an interdisciplinary context. Political ecology is one framework for analysis that is promising in developing a modified ecology of disease.

Relationships between adaptive and neutral genetic diversity and ecological structure and functioning: a meta-analysis

PubMed Central

Whitlock, Raj

2014-01-01

Understanding the effects of intraspecific genetic diversity on the structure and functioning of ecological communities is a fundamentally important part of evolutionary ecology and may also have conservation relevance in identifying the situations in which genetic diversity coincides with species-level diversity.Early studies within this field documented positive relationships between genetic diversity and ecological structure, but recent studies have challenged these findings. Conceptual synthesis has been hampered because studies have used different measures of intraspecific variation (phenotypically adaptive vs. neutral) and have considered different measures of ecological structure in different ecological and spatial contexts. The aim of this study is to strengthen conceptual understanding by providing an empirical synthesis quantifying the relationship between genetic diversity and ecological structure.Here, I present a meta-analysis of the relationship between genetic diversity within plant populations and the structure and functioning of associated ecological communities (including 423 effect sizes from 70 studies). I used Bayesian meta-analyses to examine (i) the strength and direction of this relationship, (ii) the extent to which phenotypically adaptive and neutral (molecular) measures of diversity differ in their association with ecological structure and (iii) variation in outcomes among different measures of ecological structure and in different ecological contexts.Effect sizes measuring the relationship between adaptive diversity (genotypic richness) and both community- and ecosystem-level ecological responses were small, but significantly positive. These associations were supported by genetic effects on species richness and productivity, respectively.There was no overall association between neutral genetic diversity and measures of ecological structure, but a positive correlation was observed under a limited set of demographic conditions. These results suggest that adaptive and neutral genetic diversity should not be treated as ecologically equivalent measures of intraspecific variation.Synthesis. This study advances the debate over whether relationships between genetic diversity and ecological structure are either simply positive or negative, by showing how the strength and direction of these relationships changes with different measures of diversity and in different ecological contexts. The results provide a solid foundation for assessing when and where an expanded synthesis between ecology and genetics will be most fruitful. PMID:25210204

Aphid-parasitoid community structure on genetically modified wheat.

PubMed

von Burg, Simone; van Veen, Frank J F; Álvarez-Alfageme, Fernando; Romeis, Jörg

2011-06-23

Since the introduction of genetically modified (GM) plants, one of the main concerns has been their potential effect on non-target insects. Many studies have looked at GM plant effects on single non-target herbivore species or on simple herbivore-natural enemy food chains. Agro-ecosystems, however, are characterized by numerous insect species which are involved in complex interactions, forming food webs. In this study, we looked at transgenic disease-resistant wheat (Triticum aestivum) and its effect on aphid-parasitoid food webs. We hypothesized that the GM of the wheat lines directly or indirectly affect aphids and that these effects cascade up to change the structure of the associated food webs. Over 2 years, we studied different experimental wheat lines under semi-field conditions. We constructed quantitative food webs to compare their properties on GM lines with the properties on corresponding non-transgenic controls. We found significant effects of the different wheat lines on insect community structure up to the fourth trophic level. However, the observed effects were inconsistent between study years and the variation between wheat varieties was as big as between GM plants and their controls. This suggests that the impact of our powdery mildew-resistant GM wheat plants on food web structure may be negligible and potential ecological effects on non-target insects limited.

Ecological site-based assessments of wind and water erosion: informing accelerated soil erosion management in rangelands

USGS Publications Warehouse

Webb, Nicholas P.; Herrick, Jeffrey E.; Duniway, Michael C.

2014-01-01

Accelerated soil erosion occurs when anthropogenic processes modify soil, vegetation or climatic conditions causing erosion rates at a location to exceed their natural variability. Identifying where and when accelerated erosion occurs is a critical first step toward its effective management. Here we explore how erosion assessments structured in the context of ecological sites (a land classification based on soils, landscape setting and ecological potential) and their vegetation states (plant assemblages that may change due to management) can inform systems for reducing accelerated soil erosion in rangelands. We evaluated aeolian horizontal sediment flux and fluvial sediment erosion rates for five ecological sites in southern New Mexico, USA, using monitoring data and rangeland-specific wind and water erosion models. Across the ecological sites, plots in shrub-encroached and shrub-dominated vegetation states were consistently susceptible to aeolian sediment flux and fluvial sediment erosion. Both processes were found to be highly variable for grassland and grass-succulent states across the ecological sites at the plot scale (0.25 Ha). We identify vegetation thresholds that define cover levels below which rapid (exponential) increases in aeolian sediment flux and fluvial sediment erosion occur across the ecological sites and vegetation states. Aeolian sediment flux and fluvial erosion in the study area can be effectively controlled when bare ground cover is 100 cm in length is less than ~35%. Land use and management activities that alter cover levels such that they cross thresholds, and/or drive vegetation state changes, may increase the susceptibility of areas to erosion. Land use impacts that are constrained within the range of natural variability should not result in accelerated soil erosion. Evaluating land condition against the erosion thresholds identified here will enable identification of areas susceptible to accelerated soil erosion and the development of practical management solutions.

Yellowstone Wolves and the Forces That Structure Natural Systems

PubMed Central

Dobson, Andy P.

2014-01-01

Since their introduction in 1995 and 1996, wolves have had effects on Yellowstone that ripple across the entire structure of the food web that defines biodiversity in the Northern Rockies ecosystem. Ecological interpretations of the wolves have generated a significant amount of debate about the relative strength of top-down versus bottom-up forces in determining herbivore and vegetation abundance in Yellowstone. Debates such as this are central to the resolution of broader debates about the role of natural enemies and climate as forces that structure food webs and modify ecosystem function. Ecologists need to significantly raise the profile of these discussions; understanding the forces that structure food webs and determine species abundance and the supply of ecosystem services is one of the central scientific questions for this century; its complexity will require new minds, new mathematics, and significant, consistent funding. PMID:25535737

Influence of a breakwater on nearby rocky intertidal community structure.

PubMed

Martins, Gustavo M; Amaral, André F; Wallenstein, Francisco M; Neto, Ana I

2009-01-01

It is widely recognised that coastal-defence structures generally affect the structure of the assemblages they support, yet their impact on adjacent systems has been largely ignored. Breakwaters modify the nearby physical environment (e.g. wave action) suggesting a local impact on biological parameters. In the present study, an ACI (After-Control-Impact) design was used to test the general hypothesis that the artificial sheltering of an exposed coast has a strong effect on the structure and functioning of adjacent systems. The effects of a reduction in hydrodynamics were clear for a number of taxa and included the replacement of barnacles, limpets and frondose algae by an increasing cover of ephemeral algae. These effects were evident both at early and late successional stages. Results suggest that the artificial sheltering of naturally exposed coasts can have a strong impact promoting a shift from consumer- to producer-dominated communities, which has important ecological and energetic consequences for the ecosystem.

[Reconstruction of urban land space based on minimum cumulative resistance model: a case study of Xintang Town, Guangzhou City].

PubMed

Zhong, Shi-Yu; Wu, Qing; Li, Yu; Cheng, Jin-Ping

2012-11-01

Based on the source-sink landscape theory and the principles of ecosystem services, the minimum cumulative resistance (MCR) model was modified, where the urban center construction land was taken as the expansion source, and the contribution rate of ecological land ecosystem services value was considered as the resistance coefficient. With the modified MCR, the urban spatial expansion process of Xintang Town, Guangzhou City was successfully simulated, and, based on the protection of ecological security pattern, the optimum path for reconstructing urban land space was put forward. The simulated urban spatial expansion short path in 1988-2008 was in accordance with the real situation. By the modified MCR, the urban space was divided into four zones of high, higher, medium, and low resistance, with the area of 80.84, 78.90, 24.26, and 61.88 km2, respectively. The expansion path of the urban space was along the route from low to medium and then to high resistance zones successively. The land suitable for eco-protection and construction had an area of 159.74 km2 and 86.14 km2, while the ecological conflict area (17.37 km2) was mainly located in higher and high resistance zones, being 10.38 and 6.99 km2, respectively. The modified MCR could not only effectively reflect the distribution area of urban land use and the conflict relationship between urban construction and ecological protection, but also reasonably judge the best developmental short path for urban spatial expansion.

Responses of seagrass to anthropogenic and natural disturbances do not equally translate to its consumers.

PubMed

Tomas, Fiona; Martínez-Crego, Begoña; Hernán, Gema; Santos, Rui

2015-11-01

Coastal communities are under threat from many and often co-occurring local (e.g., pollution, eutrophication) and global stressors (e.g., climate change), yet understanding the interactive and cumulative impacts of multiple stressors in ecosystem function is far from being accomplished. Ecological redundancy may be key for ecosystem resilience, but there are still many gaps in our understanding of interspecific differences within a functional group, particularly regarding response diversity, that is, whether members of a functional group respond equally or differently to anthropogenic stressors. Herbivores are critical in determining plant community structure and the transfer of energy up the food web. Human disturbances may alter the ecological role of herbivory by modifying the defense strategies of plants and thus the feeding patterns and performance of herbivores. We conducted a suite of experiments to examine the independent and interactive effects of anthropogenic (nutrient and CO2 additions) and natural (simulated herbivory) disturbances on a seagrass and its interaction with two common generalist consumers to understand how multiple disturbances can impact both a foundation species and a key ecological function (herbivory) and to assess the potential existence of response diversity to anthropogenic and natural changes in these systems. While all three disturbances modified seagrass defense traits, there were contrasting responses of herbivores to such plant changes. Both CO2 and nutrient additions influenced herbivore feeding behavior, yet while sea urchins preferred nutrient-enriched seagrass tissue (regardless of other experimental treatments), isopods were deterred by these same plant tissues. In contrast, carbon enrichment deterred sea urchins and attracted isopods, while simulated herbivory only influenced isopod feeding choice. These contrasting responses of herbivores to disturbance-induced changes in seagrass help to better understand the ecological functioning of seagrass ecosystems in the face of human disturbances and may have important implications regarding the resilience and conservation of these threatened ecosystems. © 2015 John Wiley & Sons Ltd.

The ecology, evolution, impacts and management of host-parasite interactions of marine molluscs.

PubMed

Coen, Loren D; Bishop, Melanie J

2015-10-01

Molluscs are economically and ecologically important components of aquatic ecosystems. In addition to supporting valuable aquaculture and wild-harvest industries, their populations determine the structure of benthic communities, cycling of nutrients, serve as prey resources for higher trophic levels and, in some instances, stabilize shorelines and maintain water quality. This paper reviews existing knowledge of the ecology of host-parasite interactions involving marine molluscs, with a focus on gastropods and bivalves. It considers the ecological and evolutionary impacts of molluscan parasites on their hosts and vice versa, and on the communities and ecosystems in which they are a part, as well as disease management and its ecological impacts. An increasing number of case studies show that disease can have important effects on marine molluscs, their ecological interactions and ecosystem services, at spatial scales from centimeters to thousands of kilometers and timescales ranging from hours to years. In some instances the cascading indirect effects arising from parasitic infection of molluscs extend well beyond the temporal and spatial scales at which molluscs are affected by disease. In addition to the direct effects of molluscan disease, there can be large indirect impacts on marine environments resulting from strategies, such as introduction of non-native species and selective breeding for disease resistance, put in place to manage disease. Much of our understanding of impacts of molluscan diseases on the marine environment has been derived from just a handful of intensively studied marine parasite-host systems, namely gastropod-trematode, cockle-trematode, and oyster-protistan interactions. Understanding molluscan host-parasite dynamics is of growing importance because: (1) expanding aquaculture; (2) current and future climate change; (3) movement of non-native species; and (4) coastal development are modifying molluscan disease dynamics, ultimately leading to complex relationships between diseases and cultivated and natural molluscan populations. Further, in some instances the enhancement or restoration of valued ecosystem services may be contingent on management of molluscan disease. The application of newly emerging molecular tools and remote sensing techniques to the study of molluscan disease will be important in identifying how changes at varying spatial and temporal scales with global change are modifying host-parasite systems. Copyright © 2015 Elsevier Inc. All rights reserved.

Bi-dimensional null model analysis of presence-absence binary matrices.

PubMed

Strona, Giovanni; Ulrich, Werner; Gotelli, Nicholas J

2018-01-01

Comparing the structure of presence/absence (i.e., binary) matrices with those of randomized counterparts is a common practice in ecology. However, differences in the randomization procedures (null models) can affect the results of the comparisons, leading matrix structural patterns to appear either "random" or not. Subjectivity in the choice of one particular null model over another makes it often advisable to compare the results obtained using several different approaches. Yet, available algorithms to randomize binary matrices differ substantially in respect to the constraints they impose on the discrepancy between observed and randomized row and column marginal totals, which complicates the interpretation of contrasting patterns. This calls for new strategies both to explore intermediate scenarios of restrictiveness in-between extreme constraint assumptions, and to properly synthesize the resulting information. Here we introduce a new modeling framework based on a flexible matrix randomization algorithm (named the "Tuning Peg" algorithm) that addresses both issues. The algorithm consists of a modified swap procedure in which the discrepancy between the row and column marginal totals of the target matrix and those of its randomized counterpart can be "tuned" in a continuous way by two parameters (controlling, respectively, row and column discrepancy). We show how combining the Tuning Peg with a wise random walk procedure makes it possible to explore the complete null space embraced by existing algorithms. This exploration allows researchers to visualize matrix structural patterns in an innovative bi-dimensional landscape of significance/effect size. We demonstrate the rational and potential of our approach with a set of simulated and real matrices, showing how the simultaneous investigation of a comprehensive and continuous portion of the null space can be extremely informative, and possibly key to resolving longstanding debates in the analysis of ecological matrices. © 2017 The Authors. Ecology, published by Wiley Periodicals, Inc., on behalf of the Ecological Society of America.

Emulating natural disturbance regimes: an emerging approach for sustainable forest management

Treesearch

M. North; W Keeton

2008-01-01

Sustainable forest management integrates ecological, social, and economic objectives. To achieve the former, researchers and practitioners are modifying silvicultural practices based on concepts from successional and landscape ecology to provide a broader array of ecosystem functions than is associated with conventional approaches. One...

Exploring the Realized Niche: Simulated Ecological Mapping with a Microcomputer.

ERIC Educational Resources Information Center

Kent, J. W.

1983-01-01

Describes a computer program based upon field observations of littoral zonation modified by a small stream. The program employs user-defined color graphic characters to display simulated ecological maps representing the patterning of organisms in response to local values of niche limiting factors. (Author/JN)

Embodied niche construction in the hominin lineage: semiotic structure and sustained attention in human embodied cognition

PubMed Central

Stutz, Aaron J.

2014-01-01

Human evolution unfolded through a rather distinctive, dynamically constructed ecological niche. The human niche is not only generally terrestrial in habitat, while being flexibly and extensively heterotrophic in food-web connections. It is also defined by semiotically structured and structuring embodied cognitive interfaces, connecting the individual organism with the wider environment. The embodied dimensions of niche-population co-evolution have long involved semiotic system construction, which I hypothesize to be an evolutionarily primitive aspect of learning and higher-level cognitive integration and attention in the great apes and humans alike. A clearly pre-linguistic form of semiotic cognitive structuration is suggested to involve recursively learned and constructed object icons. Higher-level cognitive iconic representation of visually, auditorily, or haptically perceived extrasomatic objects would be learned and evoked through indexical connections to proprioceptive and affective somatic states. Thus, private cognitive signs would be defined, not only by their learned and perceived extrasomatic referents, but also by their associations to iconically represented somatic states. This evolutionary modification of animal associative learning is suggested to be adaptive in ecological niches occupied by long-lived, large-bodied ape species, facilitating memory construction and recall in highly varied foraging and social contexts, while sustaining selective attention during goal-directed behavioral sequences. The embodied niche construction (ENC) hypothesis of human evolution posits that in the early hominin lineage, natural selection further modified the ancestral ape semiotic adaptations, favoring the recursive structuration of concise iconic narratives of embodied interaction with the environment. PMID:25136323

Embodied niche construction in the hominin lineage: semiotic structure and sustained attention in human embodied cognition.

PubMed

Stutz, Aaron J

2014-01-01

Human evolution unfolded through a rather distinctive, dynamically constructed ecological niche. The human niche is not only generally terrestrial in habitat, while being flexibly and extensively heterotrophic in food-web connections. It is also defined by semiotically structured and structuring embodied cognitive interfaces, connecting the individual organism with the wider environment. The embodied dimensions of niche-population co-evolution have long involved semiotic system construction, which I hypothesize to be an evolutionarily primitive aspect of learning and higher-level cognitive integration and attention in the great apes and humans alike. A clearly pre-linguistic form of semiotic cognitive structuration is suggested to involve recursively learned and constructed object icons. Higher-level cognitive iconic representation of visually, auditorily, or haptically perceived extrasomatic objects would be learned and evoked through indexical connections to proprioceptive and affective somatic states. Thus, private cognitive signs would be defined, not only by their learned and perceived extrasomatic referents, but also by their associations to iconically represented somatic states. This evolutionary modification of animal associative learning is suggested to be adaptive in ecological niches occupied by long-lived, large-bodied ape species, facilitating memory construction and recall in highly varied foraging and social contexts, while sustaining selective attention during goal-directed behavioral sequences. The embodied niche construction (ENC) hypothesis of human evolution posits that in the early hominin lineage, natural selection further modified the ancestral ape semiotic adaptations, favoring the recursive structuration of concise iconic narratives of embodied interaction with the environment.

A typology of time-scale mismatches and behavioral interventions to diagnose and solve conservation problems

USGS Publications Warehouse

Wilson, Robyn S.; Hardisty, David J.; Epanchin-Niell, Rebecca S.; Runge, Michael C.; Cottingham, Kathryn L.; Urban, Dean L.; Maguire, Lynn A.; Hastings, Alan; Mumby, Peter J.; Peters, Debra P.C.

2016-01-01

Ecological systems often operate on time scales significantly longer or shorter than the time scales typical of human decision making, which causes substantial difficulty for conservation and management in socioecological systems. For example, invasive species may move faster than humans can diagnose problems and initiate solutions, and climate systems may exhibit long-term inertia and short-term fluctuations that obscure learning about the efficacy of management efforts in many ecological systems. We adopted a management-decision framework that distinguishes decision makers within public institutions from individual actors within the social system, calls attention to the ways socioecological systems respond to decision makers’ actions, and notes institutional learning that accrues from observing these responses. We used this framework, along with insights from bedeviling conservation problems, to create a typology that identifies problematic time-scale mismatches occurring between individual decision makers in public institutions and between individual actors in the social or ecological system. We also considered solutions that involve modifying human perception and behavior at the individual level as a means of resolving these problematic mismatches. The potential solutions are derived from the behavioral economics and psychology literature on temporal challenges in decision making, such as the human tendency to discount future outcomes at irrationally high rates. These solutions range from framing environmental decisions to enhance the salience of long-term consequences, to using structured decision processes that make time scales of actions and consequences more explicit, to structural solutions aimed at altering the consequences of short-sighted behavior to make it less appealing. Additional application of these tools and long-term evaluation measures that assess not just behavioral changes but also associated changes in ecological systems are needed.

A typology of time-scale mismatches and behavioral interventions to diagnose and solve conservation problems.

PubMed

Wilson, Robyn S; Hardisty, David J; Epanchin-Niell, Rebecca S; Runge, Michael C; Cottingham, Kathryn L; Urban, Dean L; Maguire, Lynn A; Hastings, Alan; Mumby, Peter J; Peters, Debra P C

2016-02-01

Ecological systems often operate on time scales significantly longer or shorter than the time scales typical of human decision making, which causes substantial difficulty for conservation and management in socioecological systems. For example, invasive species may move faster than humans can diagnose problems and initiate solutions, and climate systems may exhibit long-term inertia and short-term fluctuations that obscure learning about the efficacy of management efforts in many ecological systems. We adopted a management-decision framework that distinguishes decision makers within public institutions from individual actors within the social system, calls attention to the ways socioecological systems respond to decision makers' actions, and notes institutional learning that accrues from observing these responses. We used this framework, along with insights from bedeviling conservation problems, to create a typology that identifies problematic time-scale mismatches occurring between individual decision makers in public institutions and between individual actors in the social or ecological system. We also considered solutions that involve modifying human perception and behavior at the individual level as a means of resolving these problematic mismatches. The potential solutions are derived from the behavioral economics and psychology literature on temporal challenges in decision making, such as the human tendency to discount future outcomes at irrationally high rates. These solutions range from framing environmental decisions to enhance the salience of long-term consequences, to using structured decision processes that make time scales of actions and consequences more explicit, to structural solutions aimed at altering the consequences of short-sighted behavior to make it less appealing. Additional application of these tools and long-term evaluation measures that assess not just behavioral changes but also associated changes in ecological systems are needed. © 2015 Society for Conservation Biology.

Defining Disturbance for Microbial Ecology.

PubMed

Plante, Craig J

2017-08-01

Disturbance can profoundly modify the structure of natural communities. However, microbial ecologists' concept of "disturbance" has often deviated from conventional practice. Definitions (or implicit usage) have frequently included climate change and other forms of chronic environmental stress, which contradict the macrobiologist's notion of disturbance as a discrete event that removes biomass. Physical constraints and disparate biological characteristics were compared to ask whether disturbances fundamentally differ in microbial and macroorganismal communities. A definition of "disturbance" for microbial ecologists is proposed that distinguishes from "stress" and other competing terms, and that is in accord with definitions accepted by plant and animal ecologists.

Southwestern Grassland Ecology

Treesearch

Paulette L. Ford; Deborah U. Potter; Rosemary Pendleton; Burton Pendleton; Wayne A. Robbie; Gerald J. Gottfried

2004-01-01

This chapter provides a brief overview, and selected in-depth coverage, of the factors and processes that have formed, and continue to shape, our Southwestern grasslands. In general, this chapter looks at how distributions of grasslands are regulated by soils and climate, and modified by disturbance (natural and/or anthropogenic). The attendant ecological components of...

Resilience amongst Older Colombians Living in Poverty: an Ecological Approach.

PubMed

Bennett, Kate M; Reyes-Rodriguez, Maria F; Altamar, Paula; Soulsby, Laura K

2016-12-01

Older Colombians face significant adversities: poverty, violence and displacement. However, there is evidence that Latinos are often resilient. We examine resilience in older Colombians living in poverty using an ecological framework that identifies three levels: individual; community; and societal. In this paper we examine data from 16 semi-structured interviews with older Colombians that explore resilience within the context of poverty. We analyze our data using three stages: (1) modified grounded theory; (2) assignment of resilience status; (3) identification of components of the ecological framework which contribute to resilience in these participants. The most striking feature is that some participants are able to adapt to their situation, demonstrating resilience, whilst others are not. Individual characteristics such as psychological and material resources contribute to resilience. At the community level, family, social support, participation and cohesion promote resilience. Finally, at the societal level, social and welfare services, finance, religion and social policy, are important factors. These different levels of resilience are co-dependent, and we illustrate how this is so. We suggest that older Colombians living in poverty often demonstrate resilience, but that more can be done to enhance their lives. This includes interventions at the individual and community levels alongside changes in social policy.

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.

Trapping Efficiency of Agricultural Runoff in a Modified Riverine Backwater Wetland

USDA-ARS?s Scientific Manuscript database

Riverine backwater wetlands within river floodplains have important economic and ecological functions such as acting as filters for suspended sediment, nutrients and pesticides entering from adjacent agricultural fields. These wetlands hydrology can be modified to increase the efficiency of their n...

A conceptual framework for the design of environmental post-market monitoring of genetically modified plants.

PubMed

Sanvido, Olivier; Widmer, Franco; Winzeler, Michael; Bigler, Franz

2005-01-01

Genetically modified plants (GMPs) may soon be cultivated commercially in several member countries of the European Union (EU). According to EU Directive 2001/18/EC, post-market monitoring (PMM) for commercial GMP cultivation must be implemented, in order to detect and prevent adverse effects on human health and the environment. However, no general PMM strategies for GMP cultivation have been established so far. We present a conceptual framework for the design of environmental PMM for GMP cultivation based on current EU legislation and common risk analysis procedures. We have established a comprehensive structure of the GMP approval process, consisting of pre-market risk assessment (PMRA) as well as PMM. Both programs can be distinguished conceptually due to principles inherent to risk analysis procedures. The design of PMM programs should take into account the knowledge gained during approval for commercialization of a specific GMP and the decisions made in the environmental risk assessments (ERAs). PMM is composed of case-specific monitoring (CSM) and general surveillance. CSM focuses on anticipated effects of a specific GMP. Selection of case-specific indicators for detection of ecological exposure and effects, as well as definition of effect sizes, are important for CSM. General surveillance is designed to detect unanticipated effects on general safeguard subjects, such as natural resources, which must not be adversely affected by human activities like GMP cultivation. We have identified clear conceptual differences between CSM and general surveillance, and propose to adopt separate frameworks when developing either of the two programs. Common to both programs is the need to put a value on possible ecological effects of GMP cultivation. The structure of PMM presented here will be of assistance to industry, researchers, and regulators, when assessing GMPs during commercialization.

Modeling invasion of metastasizing cancer cells to bone marrow utilizing ecological principles.

PubMed

Chen, Kun-Wan; Pienta, Kenneth J

2011-10-03

The invasion of a new species into an established ecosystem can be directly compared to the steps involved in cancer metastasis. Cancer must grow in a primary site, extravasate and survive in the circulation to then intravasate into target organ (invasive species survival in transport). Cancer cells often lay dormant at their metastatic site for a long period of time (lag period for invasive species) before proliferating (invasive spread). Proliferation in the new site has an impact on the target organ microenvironment (ecological impact) and eventually the human host (biosphere impact). Tilman has described mathematical equations for the competition between invasive species in a structured habitat. These equations were adapted to study the invasion of cancer cells into the bone marrow microenvironment as a structured habitat. A large proportion of solid tumor metastases are bone metastases, known to usurp hematopoietic stem cells (HSC) homing pathways to establish footholds in the bone marrow. This required accounting for the fact that this is the natural home of hematopoietic stem cells and that they already occupy this structured space. The adapted Tilman model of invasion dynamics is especially valuable for modeling the lag period or dormancy of cancer cells. The Tilman equations for modeling the invasion of two species into a defined space have been modified to study the invasion of cancer cells into the bone marrow microenvironment. These modified equations allow a more flexible way to model the space competition between the two cell species. The ability to model initial density, metastatic seeding into the bone marrow and growth once the cells are present, and movement of cells out of the bone marrow niche and apoptosis of cells are all aspects of the adapted equations. These equations are currently being applied to clinical data sets for verification and further refinement of the models.

Modified social ecological model: a tool to guide the assessment of the risks and risk contexts of HIV epidemics.

PubMed

Baral, Stefan; Logie, Carmen H; Grosso, Ashley; Wirtz, Andrea L; Beyrer, Chris

2013-05-17

Social and structural factors are now well accepted as determinants of HIV vulnerabilities. These factors are representative of social, economic, organizational and political inequities. Associated with an improved understanding of multiple levels of HIV risk has been the recognition of the need to implement multi-level HIV prevention strategies. Prevention sciences research and programming aiming to decrease HIV incidence requires epidemiologic studies to collect data on multiple levels of risk to inform combination HIV prevention packages. Proximal individual-level risks, such as sharing injection devices and unprotected penile-vaginal or penile-anal sex, are necessary in mediating HIV acquisition and transmission. However, higher order social and structural-level risks can facilitate or reduce HIV transmission on population levels. Data characterizing these risks is often far more actionable than characterizing individual-level risks. We propose a modified social ecological model (MSEM) to help visualize multi-level domains of HIV infection risks and guide the development of epidemiologic HIV studies. Such a model may inform research in epidemiology and prevention sciences, particularly for key populations including men who have sex with men (MSM), people who inject drugs (PID), and sex workers. The MSEM builds on existing frameworks by examining multi-level risk contexts for HIV infection and situating individual HIV infection risks within wider network, community, and public policy contexts as well as epidemic stage. The utility of the MSEM is demonstrated with case studies of HIV risk among PID and MSM. The MSEM is a flexible model for guiding epidemiologic studies among key populations at risk for HIV in diverse sociocultural contexts. Successful HIV prevention strategies for key populations require effective integration of evidence-based biomedical, behavioral, and structural interventions. While the focus of epidemiologic studies has traditionally been on describing individual-level risk factors, the future necessitates comprehensive epidemiologic data characterizing multiple levels of HIV risk.

A simple stochastic weather generator for ecological modeling

Treesearch

A.G. Birt; M.R. Valdez-Vivas; R.M. Feldman; C.W. Lafon; D. Cairns; R.N. Coulson; M. Tchakerian; W. Xi; Jim Guldin

2010-01-01

Stochastic weather generators are useful tools for exploring the relationship between organisms and their environment. This paper describes a simple weather generator that can be used in ecological modeling projects. We provide a detailed description of methodology, and links to full C++ source code (http://weathergen.sourceforge.net) required to implement or modify...

Acorn Caching in Tree Squirrels: Teaching Hypothesis Testing in the Park

ERIC Educational Resources Information Center

McEuen, Amy B.; Steele, Michael A.

2012-01-01

We developed an exercise for a university-level ecology class that teaches hypothesis testing by examining acorn preferences and caching behavior of tree squirrels (Sciurus spp.). This exercise is easily modified to teach concepts of behavioral ecology for earlier grades, particularly high school, and provides students with a theoretical basis for…

Sustainability analysis and life-cycle ecological impacts of rainwater harvesting systems using holistic analysis and a modified eco-efficiency framework

EPA Science Inventory

Background/Question/Methods A sustainability paradigm is being recognized globally as a path forward for human prosperity and ecological health in the face of climate change and meeting challenges of the water-energy-food nexus. Rainfall shortages for drinking water and crop pro...

Modeling the Effects of Drought, Fire, Beetles, and Management on Future Carbon Cycling in the Western US

NASA Astrophysics Data System (ADS)

Buotte, P.; Law, B. E.; Hicke, J. A.; Hudiburg, T. W.; Levis, S.; Kent, J.

2017-12-01

Fire and beetle outbreaks can have substantial impacts on forest structure, composition, and function and these types of disturbances are expected to increase in the future. Therefore understanding the ecological impacts of these disturbances into the future is important. We used ecosystem process modeling to estimate the future occurrence of fire and beetle outbreaks and their impacts on forest resilience and carbon sequestration. We modified the Community Land Model (CLM4.5) to better represent forest growth and mortality in the western US through multiple avenues: 1) we increased the ecological resolution to recognize 14 forest types common to the region; 2) we improved CLM4.5's ability to handle drought stress by adding forest type-specific controls on stomatal conductance and increased rates of leaf shed during periods of low soil moisture; 3) we developed and implemented a mechanistic model of beetle population growth and subsequent tree mortality; 4) we modified the current fire module to account for more refined forest types; and 5) we developed multiple scenarios of harvest based on past harvest rates and proposed changes in land management policies. We ran CLM4.5 in offline mode with climate forcing data. We compare future forest growth rates and carbon sequestration with historical metrics to estimate the combined influence of future disturbances on forest composition and carbon sequestration in the western US.

Tidal Energy: The benthic effects of an operational tidal stream turbine.

PubMed

O'Carroll, J P J; Kennedy, R M; Creech, A; Savidge, G

2017-08-01

The effect of modified flow on epifaunal boulder reef communities adjacent to the SeaGen, the world's first grid-compliant tidal stream turbine, were assessed. The wake of the SeaGen was modelled and the outputs were used in conjunction with positional and substrate descriptor variables, to relate variation in epifaunal community structure to the modified physical environment. An Artificial Neural Network (ANN) and Generalised Linear Model (GLM) were used to make predictions on the distribution of Ecological Status (ES) of epifaunal communities in relation to the turbulent wake of the SeaGen. ES was assigned using the High Energy Hard Substrate (HEHS) index. ES was largely High throughout the survey area and it was not possible to make predictions on the spatial distribution of ES using an ANN or GLM. Spatial pattern in epifaunal community structure was detected when the study area was partitioned into three treatment areas: area D1; within one rotor diameter (16 m) of the centre of SeaGen, area D2; between one and three rotor diameters, and area D3; outside of three rotor diameters. Area D1 was found to be significantly more variable than D2 and D3 in terms of epifaunal community structure, bare rock distributions and ES. Copyright © 2017 Elsevier Ltd. All rights reserved.

The food and environmental safety of Bt crops.

PubMed

Koch, Michael S; Ward, Jason M; Levine, Steven L; Baum, James A; Vicini, John L; Hammond, Bruce G

2015-01-01

Bacillus thuringiensis (Bt) microbial pesticides have a 50-year history of safety in agriculture. Cry proteins are among the active insecticidal ingredients in these pesticides, and genes coding for Cry proteins have been introduced into agricultural crops using modern biotechnology. The Cry gene sequences are often modified to enable effective expression in planta and several Cry proteins have been modified to increase biological activity against the target pest(s). Additionally, the domains of different but structurally conserved Cry proteins can be combined to produce chimeric proteins with enhanced insecticidal properties. Environmental studies are performed and include invertebrates, mammals, and avian species. Mammalian studies used to support the food and feed safety assessment are also used to support the wild mammal assessment. In addition to the NTO assessment, the environmental assessment includes a comparative assessment between the Bt crop and the appropriate conventional control that is genetically similar but lacks the introduced trait to address unintended effects. Specific phenotypic, agronomic, and ecological characteristics are measured in the Bt crop and the conventional control to evaluate whether the introduction of the insect resistance has resulted in any changes that might cause ecological harm in terms of altered weed characteristics, susceptibility to pests, or adverse environmental impact. Additionally, environmental interaction data are collected in field experiments for Bt crop to evaluate potential adverse effects. Further to the agronomic and phenotypic evaluation, potential movement of transgenes from a genetically modified crop plants into wild relatives is assessed for a new pest resistance gene in a new crop. This review summarizes the evidence for safety of crops containing Cry proteins for humans, livestock, and other non-target organisms.

The food and environmental safety of Bt crops

PubMed Central

Koch, Michael S.; Ward, Jason M.; Levine, Steven L.; Baum, James A.; Vicini, John L.; Hammond, Bruce G.

2015-01-01

Bacillus thuringiensis (Bt) microbial pesticides have a 50-year history of safety in agriculture. Cry proteins are among the active insecticidal ingredients in these pesticides, and genes coding for Cry proteins have been introduced into agricultural crops using modern biotechnology. The Cry gene sequences are often modified to enable effective expression in planta and several Cry proteins have been modified to increase biological activity against the target pest(s). Additionally, the domains of different but structurally conserved Cry proteins can be combined to produce chimeric proteins with enhanced insecticidal properties. Environmental studies are performed and include invertebrates, mammals, and avian species. Mammalian studies used to support the food and feed safety assessment are also used to support the wild mammal assessment. In addition to the NTO assessment, the environmental assessment includes a comparative assessment between the Bt crop and the appropriate conventional control that is genetically similar but lacks the introduced trait to address unintended effects. Specific phenotypic, agronomic, and ecological characteristics are measured in the Bt crop and the conventional control to evaluate whether the introduction of the insect resistance has resulted in any changes that might cause ecological harm in terms of altered weed characteristics, susceptibility to pests, or adverse environmental impact. Additionally, environmental interaction data are collected in field experiments for Bt crop to evaluate potential adverse effects. Further to the agronomic and phenotypic evaluation, potential movement of transgenes from a genetically modified crop plants into wild relatives is assessed for a new pest resistance gene in a new crop. This review summarizes the evidence for safety of crops containing Cry proteins for humans, livestock, and other non-target organisms. PMID:25972882

Micro-evolution due to pollution: possible consequences for ecosystem responses to toxic stress.

PubMed

Medina, Matías H; Correa, Juan A; Barata, Carlos

2007-05-01

Polluting events can change community structure and ecosystem functioning. Selection of genetically inherited tolerance on exposed populations, here referred as micro-evolution due to pollution, has been recognized as one of the causes of these changes. However, there is a gap between studies addressing this process and those assessing effects at higher levels of biological organization. In this review we attempt to address these evolutionary considerations into the ecological risk assessment (ERA) of polluting events and to trigger the discussion about the consequences of this process for the ecosystem response to toxic stress. We provide clear evidence that pollution drives micro-evolutionary processes in several species. When this process occurs, populations inhabiting environments that become polluted may persist. However, due to the existence of ecological costs derived from the loss of genetic variability, negative pleiotropy with fitness traits and/or from physiological alterations, micro-evolution due to pollution may alter different properties of the affected populations. Despite the existence of empirical evidence showing that safety margins currently applied in the ERA process may account for pollution-induced genetic changes in tolerance, information regarding long-term ecological consequences at higher levels of biological organization due to ecological costs is not explicitly considered in these procedures. In relation to this, we present four testable hypotheses considering that micro-evolution due to pollution acts upon the variability of functional response traits of the exposed populations and generates changes on their functional effect traits, therefore, modifying the way species exploit their ecological niches and participate in the overall ecosystem functioning.

Prioritizing Urban Habitats for Connectivity Conservation: Integrating Centrality and Ecological Metrics.

PubMed

Poodat, Fatemeh; Arrowsmith, Colin; Fraser, David; Gordon, Ascelin

2015-09-01

Connectivity among fragmented areas of habitat has long been acknowledged as important for the viability of biological conservation, especially within highly modified landscapes. Identifying important habitat patches in ecological connectivity is a priority for many conservation strategies, and the application of 'graph theory' has been shown to provide useful information on connectivity. Despite the large number of metrics for connectivity derived from graph theory, only a small number have been compared in terms of the importance they assign to nodes in a network. This paper presents a study that aims to define a new set of metrics and compares these with traditional graph-based metrics, used in the prioritization of habitat patches for ecological connectivity. The metrics measured consist of "topological" metrics, "ecological metrics," and "integrated metrics," Integrated metrics are a combination of topological and ecological metrics. Eight metrics were applied to the habitat network for the fat-tailed dunnart within Greater Melbourne, Australia. A non-directional network was developed in which nodes were linked to adjacent nodes. These links were then weighted by the effective distance between patches. By applying each of the eight metrics for the study network, nodes were ranked according to their contribution to the overall network connectivity. The structured comparison revealed the similarity and differences in the way the habitat for the fat-tailed dunnart was ranked based on different classes of metrics. Due to the differences in the way the metrics operate, a suitable metric should be chosen that best meets the objectives established by the decision maker.

A zone-specific fish-based biotic index as a management tool for the Zeeschelde estuary (Belgium).

PubMed

Breine, Jan; Quataert, Paul; Stevens, Maarten; Ollevier, Frans; Volckaert, Filip A M; Van den Bergh, Ericia; Maes, Joachim

2010-07-01

Fish-based indices monitor changes in surface waters and are a valuable aid in communication by summarising complex information about the environment (Harrison and Whitfield, 2004). A zone-specific fish-based multimetric estuarine index of biotic integrity (Z-EBI) was developed based on a 13 year time series of fish surveys from the Zeeschelde estuary (Belgium). Sites were pre-classified using indicators of anthropogenic impact. Metrics showing a monotone response with pressure classes were selected for further analysis. Thresholds for the good ecological potential (GEP) were defined from references. A modified trisection was applied for the other thresholds. The Z-EBI is defined by the average of the metric scores calculated over a one year period and translated into an ecological quality ratio (EQR). The indices integrate structural and functional qualities of the estuarine fish communities. The Z-EBI performances were successfully validated for habitat degradation in the various habitat zones. Copyright 2010 Elsevier Ltd. All rights reserved.

Intraspecific chemical diversity among neighbouring plants correlates positively with plant size and herbivore load but negatively with herbivore damage.

PubMed

Bustos-Segura, Carlos; Poelman, Erik H; Reichelt, Michael; Gershenzon, Jonathan; Gols, Rieta

2017-01-01

Intraspecific plant diversity can modify the properties of associated arthropod communities and plant fitness. However, it is not well understood which plant traits determine these ecological effects. We explored the effect of intraspecific chemical diversity among neighbouring plants on the associated invertebrate community and plant traits. In a common garden experiment, intraspecific diversity among neighbouring plants was manipulated using three plant populations of wild cabbage that differ in foliar glucosinolates. Plants were larger, harboured more herbivores, but were less damaged when plant diversity was increased. Glucosinolate concentration differentially correlated with generalist and specialist herbivore abundance. Glucosinolate composition correlated with plant damage, while in polycultures, variation in glucosinolate concentrations among neighbouring plants correlated positively with herbivore diversity and negatively with plant damage levels. The results suggest that intraspecific variation in secondary chemistry among neighbouring plants is important in determining the structure of the associated insect community and positively affects plant performance. © 2016 The Authors. Ecology Letters published by CNRS and John Wiley & Sons Ltd.

Ecological Structure Activity Relationships

EPA Science Inventory

Ecological Structure Activity Relationships, v1.00a, February 2009
ECOSAR (Ecological Structure Activity Relationships) is a personal computer software program that is used to estimate the toxicity of chemicals used in industry and discharged into water. The program predicts...

Differences in Intertidal Microbial Assemblages on Urban Structures and Natural Rocky Reef

PubMed Central

Tan, Elisa L.-Y.; Mayer-Pinto, Mariana; Johnston, Emma L.; Dafforn, Katherine A.

2015-01-01

Global seascapes are increasingly modified to support high levels of human activity in the coastal zone. Modifications include the addition of defense structures and boating infrastructure, such as seawalls and marinas that replace natural habitats. Artificial structures support different macrofaunal communities to those found on natural rocky shores; however, little is known about differences in microbial community structure or function in urban seascapes. Understanding how artificial constructions in marine environments influence microbial communities is important as these assemblages contribute to many basic ecological processes. In this study, the bacterial communities of intertidal biofilms were compared between artificial structures (seawalls) and natural habitats (rocky shores) within Sydney Harbour. Plots were cleared on each type of habitat at eight locations. After 3 weeks the newly formed biofilm was sampled and the 16S rRNA gene sequenced using the Illumina Miseq platform. To account for differences in orientation and substrate material between seawalls and rocky shores that might have influenced our survey, we also deployed recruitment blocks next to the habitats at all locations for 3 weeks and then sampled and sequenced their microbial communities. Intertidal bacterial community structure sampled from plots differed between seawalls and rocky shores, but when substrate material, age and orientation were kept constant (with recruitment blocks) then bacterial communities were similar in composition and structure among habitats. This suggests that changes in bacterial communities on seawalls are not related to environmental differences between locations, but may be related to other intrinsic factors that differ between the habitats such as orientation, complexity, or predation. This is one of the first comparisons of intertidal microbial communities on natural and artificial surfaces and illustrates substantial ecological differences with potential consequences for biofilm function and the recruitment of macrofauna. PMID:26635747

Toward Gleasonian landscape ecology: From communities to species, from patches to pixels

Treesearch

Samuel A. Cushman; Jeffrey S. Evans; Kevin McGarigal; Joseph M. Kiesecker

2010-01-01

The fusion of individualistic community ecology with the Hutchinsonian niche concept enabled a broad integration of ecological theory, spanning all the way from the niche characteristics of individual species, to the composition, structure, and dynamics of ecological communities. Landscape ecology has been variously described as the study of the structure, function,...

Global and local disturbances interact to modify seagrass palatability.

PubMed

Jiménez-Ramos, Rocío; Egea, Luis G; Ortega, María J; Hernández, Ignacio; Vergara, Juan J; Brun, Fernando G

2017-01-01

Global change, such as warming and ocean acidification, and local anthropogenic disturbances, such as eutrophication, can have profound impacts on marine organisms. However, we are far from being able to predict the outcome of multiple interacting disturbances on seagrass communities. Herbivores are key in determining plant community structure and the transfer of energy up the food web. Global and local disturbances may alter the ecological role of herbivory by modifying leaf palatability (i.e. leaf traits) and consequently, the feeding patterns of herbivores. This study evaluates the main and interactive effects of factors related to global change (i.e. elevated temperature, lower pH levels and associated ocean acidification) and local disturbance (i.e. eutrophication through ammonium enrichment) on a broad spectrum of leaf traits using the temperate seagrass Cymodocea nodosa, including structural, nutritional, biomechanical and chemical traits. The effect of these traits on the consumption rates of the generalist herbivore Paracentrotus lividus (purple sea urchin) is evaluated. The three disturbances of warming, low pH level and eutrophication, alone and in combination, increased the consumption rate of seagrass by modifying all leaf traits. Leaf nutritional quality, measured as nitrogen content, was positively correlated to consumption rate. In contrast, a negative correlation was found between feeding decisions by sea urchins and structural, biomechanical and chemical leaf traits. In addition, a notable accomplishment of this work is the identification of phenolic compounds not previously reported for C. nodosa. Our results suggest that global and local disturbances may trigger a major shift in the herbivory of seagrass communities, with important implications for the resilience of seagrass ecosystems.

A technological approach to studying motor planning ability in children at high risk for ASD.

PubMed

Taffoni, F; Focaroli, V; Keller, F; Iverson, J M

2014-01-01

In this work we propose a new method to study the development of motor planning abilities in children and, in particular, in children at high risk for ASD. Although several modified motor signs have been found in children with ASD, no specific markers enabling the early assessment of risk have been found yet. In this work, we discuss the problem posed by objective and quantitative behavioral analysis in non-structured environment. After an initial description of the main constraints imposed by the ecological approach, a technological and methodological solution to these issues is presented. Preliminary results on 12 children are reported and briefly discussed.

Translating the Socio-Ecological Perspective into Multilevel Interventions: Gaps between Theory and Practice

ERIC Educational Resources Information Center

Schölmerich, Vera L. N.; Kawachi, Ichiro

2016-01-01

Multilevel interventions are inspired by socio-ecological models, and seek to create change on various levels--for example by increasing the health literacy of individuals as well as modifying the social norms within a community. Despite becoming a buzzword in public health, actual multilevel interventions remain scarce. In this commentary, we…

Socio-ecological implications of modifying rotation lengths in forestry.

PubMed

Roberge, Jean-Michel; Laudon, Hjalmar; Björkman, Christer; Ranius, Thomas; Sandström, Camilla; Felton, Adam; Sténs, Anna; Nordin, Annika; Granström, Anders; Widemo, Fredrik; Bergh, Johan; Sonesson, Johan; Stenlid, Jan; Lundmark, Tomas

2016-02-01

The rotation length is a key component of even-aged forest management systems. Using Fennoscandian forestry as a case, we review the socio-ecological implications of modifying rotation lengths relative to current practice by evaluating effects on a range of ecosystem services and on biodiversity conservation. The effects of shortening rotations on provisioning services are expected to be mostly negative to neutral (e.g. production of wood, bilberries, reindeer forage), while those of extending rotations would be more varied. Shortening rotations may help limit damage by some of today's major damaging agents (e.g. root rot, cambium-feeding insects), but may also increase other damage types (e.g. regeneration pests) and impede climate mitigation. Supporting (water, soil nutrients) and cultural (aesthetics, cultural heritage) ecosystem services would generally be affected negatively by shortened rotations and positively by extended rotations, as would most biodiversity indicators. Several effect modifiers, such as changes to thinning regimes, could alter these patterns.

Coastal defence through low crested breakwater structures: jumping out of the frying pan into the fire?

PubMed

Munari, Cristina; Corbau, Corinne; Simeoni, Umberto; Mistri, Michele

2011-08-01

The Adriatic coast of Punta Marina (Ravenna) is protected by 3-km long low crested breakwater structures (LCSs). Through a 3-years long multidisciplinar study, we assessed the impact of such defensive structures on environmental and biological condition. LCSs create pools where conditions are very different from the surrounding nearshore system. Mechanical disturbance by currents and waves varied greatly in intensity and frequency between seaward and landward sides of the structures. Sedimentary budget was positive at the landward side, but it was due to a gain on the seafloor and not on the emerged beach. The budget at seaward was negative. LCSs determine differences in benthic assemblages, alter the seasonal pattern of communities, and modify seasonal fluctuations of animal assemblages. Landward sheltered areas can be seen as "lagoonal island" surrounded by a "sea of marine habitat". Differences in ecological quality status, obtained through M-AMBI, are due to the sum of these factors. Copyright © 2011 Elsevier Ltd. All rights reserved.

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.

The Modified-Classroom Observation Schedule to Measure Intentional Communication (M-COSMIC): Evaluation of Reliability and Validity

ERIC Educational Resources Information Center

Clifford, Sally; Hudry, Kristelle; Brown, Laura; Pasco, Greg; Charman, Tony

2010-01-01

The Modified-Classroom Observation Schedule to Measure Intentional Communication (M-COSMIC) was developed as an ecologically valid measure of social-communication behaviour, delineating forms, functions, and intended partners of children's spontaneous communication acts. Forty-one children with autism spectrum disorder (ASD) aged 48-73 months were…

ASSESSING POSSIBLE ECOLOGICAL RISKS OF GENETICALLY MODIFIED CROPS: GENE EXPRESSION ASSAYS AND GENETIC MONITORING OF NON-TARGET ORGANISMS

EPA Science Inventory

Widespread planting of genetically modified crops with the Bt transgene pesticide has led to concern over non-target effects of Bt compounds in agroecosystems. While some research suggests that non-target organisms exposed to Bt toxin exhibit reduced fecundity and increased morta...

HeLM: a macrophyte-based method for monitoring and assessment of Greek lakes.

PubMed

Zervas, Dimitrios; Tsiaoussi, Vasiliki; Tsiripidis, Ioannis

2018-05-05

The Water Framework Directive (WFD) requires Member States to develop appropriate assessment methods for the classification of the ecological status of their surface waters. Mediterranean region has lagged behind in this task, so we propose here the first developed method for Greek lakes, Hellenic Lake Macrophyte (HeLM) assessment method. This method is based on two metrics, a modified trophic index and maximum colonization depth C max that quantify the degree of changes in lake macrophytic vegetation, as a response to eutrophication and general degradation pressures. The method was developed on the basis of a data set sampled from 272 monitoring transects in 16 Greek lakes. Sites from three lakes were selected as potential reference sites by using a screening process. Ecological quality ratios were calculated for each metric and for each lake, and ecological status class boundaries were defined. For the evaluation of effectiveness of the method, the correlations between individual metrics and final HeLM values and common pressure indicators, such as total phosphorus, chlorophyll a and Secchi depth, were tested and found highly significant and relatively strong. In addition, the ability of HeLM values and its individual metrics to distinguish between different macrophytic communities' structure was checked using aquatic plant life-forms and found satisfactory. The HeLM method gave a reliable assessment of the macrophytic vegetation's condition in Greek lakes and may constitute a useful tool for the classification of ecological status of other Mediterranean lakes.

The Ecology of Collaborative Work. Workscape 21: The Ecology of New Ways of Working.

ERIC Educational Resources Information Center

Becker, Franklin; Quinn, Kristen L.; Tennessen, Carolyn M.

A study examined Chiat/Day inc. Advertising's team-based virtual office in which work could occur at any location inside or outside the office at any time. Three sites used three workplace strategies: full virtual (FV), modified virtual (MV), and conventional (C). Interviews, observations, and archival data were used to assess project teams doing…

Aboveground and belowground arthropods experience different relative influences of stochastic versus deterministic community assembly processes following disturbance

PubMed Central

Martinez, Alexander S.; Faist, Akasha M.

2016-01-01

Background Understanding patterns of biodiversity is a longstanding challenge in ecology. Similar to other biotic groups, arthropod community structure can be shaped by deterministic and stochastic processes, with limited understanding of what moderates the relative influence of these processes. Disturbances have been noted to alter the relative influence of deterministic and stochastic processes on community assembly in various study systems, implicating ecological disturbances as a potential moderator of these forces. Methods Using a disturbance gradient along a 5-year chronosequence of insect-induced tree mortality in a subalpine forest of the southern Rocky Mountains, Colorado, USA, we examined changes in community structure and relative influences of deterministic and stochastic processes in the assembly of aboveground (surface and litter-active species) and belowground (species active in organic and mineral soil layers) arthropod communities. Arthropods were sampled for all years of the chronosequence via pitfall traps (aboveground community) and modified Winkler funnels (belowground community) and sorted to morphospecies. Community structure of both communities were assessed via comparisons of morphospecies abundance, diversity, and composition. Assembly processes were inferred from a mixture of linear models and matrix correlations testing for community associations with environmental properties, and from null-deviation models comparing observed vs. expected levels of species turnover (Beta diversity) among samples. Results Tree mortality altered community structure in both aboveground and belowground arthropod communities, but null models suggested that aboveground communities experienced greater relative influences of deterministic processes, while the relative influence of stochastic processes increased for belowground communities. Additionally, Mantel tests and linear regression models revealed significant associations between the aboveground arthropod communities and vegetation and soil properties, but no significant association among belowground arthropod communities and environmental factors. Discussion Our results suggest context-dependent influences of stochastic and deterministic community assembly processes across different fractions of a spatially co-occurring ground-dwelling arthropod community following disturbance. This variation in assembly may be linked to contrasting ecological strategies and dispersal rates within above- and below-ground communities. Our findings add to a growing body of evidence indicating concurrent influences of stochastic and deterministic processes in community assembly, and highlight the need to consider potential variation across different fractions of biotic communities when testing community ecology theory and considering conservation strategies. PMID:27761333

Ecological periodic tables: Killer apps for translational ecology

EPA Science Inventory

The chemical periodic table, the Linnaean system of classification and the Hertzsprung-Russell diagram are information organizing structures that have transformed chemistry, biology and astronomy, respectively. Ecological periodic tables are information organizing structures wit...

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.

[Effects of land use structure change on regional ecological health--taking Shapingba County as an example].

PubMed

Wang, Cheng; Wei, Chaofu; Gao, Ming; Luo, Guanglian; Jiang, Wei

2005-12-01

Land resource is the carrier for the exchange of matter, energy and information flows, while the change velocity and the intensity of land use has strong effects on the ecological processes such as matter circulation, energy flow, and biologic diversity. Land use structure change will alter the type, area, and spatial distribution of ecosystem, and in the meantime, result in the changes of regional ecological health. Employing the principles and methods of landscape ecology, and through endowing relative ecological value to land use type, this paper analyzed the charaeteristics of recent 10 years land use change in Shapingba County of Chongqing, and discussed the effects of land use change on regional ecological health, aimed to provide scientific references for land use planning and sustainable land resource utilization. The results indicated that transformation often occurred among different land use types, and the land use structure in each transformation phase differed quite obviously. Under different land use structure, there was a great disparity in relative ecological value of sub-ecosystems, which played various roles in regional ecological health. In general, the regional relative ecological value embodied both increase and decrease. In the future, the relative ecological value of sub-ecosystem would represent three tendencies, i.e., increase first and decrease then, continuous decrease, and continuous increase. The situation of regional ecological health would gradually become better.

A rapid method to score stream reaches based on the overall performance of their main ecological functions.

PubMed

Rowe, David K; Parkyn, Stephanie; Quinn, John; Collier, Kevin; Hatton, Chris; Joy, Michael K; Maxted, John; Moore, Stephen

2009-06-01

A method was developed to score the ecological condition of first- to third-order stream reaches in the Auckland region of New Zealand based on the performance of their key ecological functions. Such a method is required by consultants and resource managers to quantify the reduction in ecological condition of a modified stream reach relative to its unmodified state. This is a fundamental precursor for the determination of fair environmental compensation for achieving no-net-loss in overall stream ecological value. Field testing and subsequent use of the method indicated that it provides a useful measure of ecological condition related to the performance of stream ecological functions. It is relatively simple to apply compared to a full ecological study, is quick to use, and allows identification of the degree of impairment of each of the key ecological functions. The scoring system was designed so that future improvements in the measurement of stream functions can be incorporated into it. Although the methodology was specifically designed for Auckland streams, the principles can be readily adapted to other regions and stream types.

Ecology and Task Structures in Adventure Education

ERIC Educational Resources Information Center

Zmudy, Mark H.; Curtner-Smith, Matthew D.; Steffen, Jeff

2009-01-01

Many of the characteristics of effective physical education lessons have been discovered by sport pedagogy researchers by employing what has become known as the ecological or task structures perspective. The purpose of this study was to describe the task structures and ecology that existed in two consecutive 7-day summer adventure camps run by an…

Ecological periodic tables: in principle and practice - January 2013

EPA Science Inventory

The chemical periodic table, the Linnaean system of classification and the Hertzsprung-Russell diagram are iconic information organizing structures in chemistry, biology and astronomy, respectively. Ecological periodic tables are information organizing structures for ecology. T...

Heating up relations between cold fish: competition modifies responses to climate change.

PubMed

Urban, Mark C; Holt, Robert D; Gilman, Sarah E; Tewksbury, Joshua

2011-05-01

Most predictions about species responses to climate change ignore species interactions. Helland and colleagues (2011) test whether this assumption is valid by evaluating whether ice cover affects competition between brown trout [Salmo trutta (L.)] and Arctic charr [Salvelinus alpines (L.)]. They show that increasing ice cover correlates with lower trout biomass when Arctic charr co-occur, but not in charr's absence. In experiments, charr grew better in the cold, dark environments that typify ice-covered lakes. Decreasing ice cover with warmer winters could mean more trout and fewer charr. More generally, their results provide an excellent example, suggesting that species interactions can strongly modify responses to climate change. © 2011 The Authors. Journal of Animal Ecology © 2011 British Ecological Society.

Microbiome engineering: Current applications and its future.

PubMed

Foo, Jee Loon; Ling, Hua; Lee, Yung Seng; Chang, Matthew Wook

2017-03-01

Microbiomes exist in all ecosystems and are composed of diverse microbial communities. Perturbation to microbiomes brings about undesirable phenotypes in the hosts, resulting in diseases and disorders, and disturbs the balance of the associated ecosystems. Engineering of microbiomes can be used to modify structures of the microbiota and restore ecological balance. Consequently, microbiome engineering has been employed for improving human health and agricultural productivity. The importance and current applications of microbiome engineering, particularly in humans, animals, plants and soil is reviewed. Furthermore, we explore the challenges in engineering microbiome and the future of this field, thus providing perspectives and outlook of microbiome engineering. Copyright © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ecological and Evolutionary Effects of Stickleback on Community Structure

PubMed Central

Des Roches, Simone; Shurin, Jonathan B.; Schluter, Dolph; Harmon, Luke J.

2013-01-01

Species’ ecology and evolution can have strong effects on communities. Both may change concurrently when species colonize a new ecosystem. We know little, however, about the combined effects of ecological and evolutionary change on community structure. We simultaneously examined the effects of top-predator ecology and evolution on freshwater community parameters using recently evolved generalist and specialist ecotypes of three-spine stickleback (Gasterosteus aculeatus). We used a mesocosm experiment to directly examine the effects of ecological (fish presence and density) and evolutionary (phenotypic diversity and specialization) factors on community structure at lower trophic levels. We evaluated zooplankton biomass and composition, periphyton and phytoplankton chlorophyll-a concentration, and net primary production among treatments containing different densities and diversities of stickleback. Our results showed that both ecological and evolutionary differences in the top-predator affect different aspects of community structure and composition. Community structure, specifically the abundance of organisms at each trophic level, was affected by stickleback presence and density, whereas composition of zooplankton was influenced by stickleback diversity and specialization. Primary productivity, in terms of chlorophyll-a concentration and net primary production was affected by ecological but not evolutionary factors. Our results stress the importance of concurrently evaluating both changes in density and phenotypic diversity on the structure and composition of communities. PMID:23573203

Pronounced differences in genetic structure despite overall ecological similarity for two Ambystoma salamanders in the same landscape

Treesearch

Andrew R. Whiteley; Kevin McGarigal; Michael K. Schwartz

2014-01-01

Studies linking genetic structure in amphibian species with ecological characteristics have focused on large differences in dispersal capabilities. Here, we test whether two species with similar dispersal potential but subtle differences in other ecological characteristics also exhibit strong differences in genetic structure in the same landscape. We examined eight...

The Role of Model Complexity in Determining Patterns of Chlorophyll Variability in the Coastal Northwest North Atlantic

NASA Astrophysics Data System (ADS)

Kuhn, A. M.; Fennel, K.; Bianucci, L.

2016-02-01

A key feature of the North Atlantic Ocean's biological dynamics is the annual phytoplankton spring bloom. In the region comprising the continental shelf and adjacent deep ocean of the northwest North Atlantic, we identified two patterns of bloom development: 1) locations with cold temperatures and deep winter mixed layers, where the spring bloom peaks around April and the annual chlorophyll cycle has a large amplitude, and 2) locations with warmer temperatures and shallow winter mixed layers, where the spring bloom peaks earlier in the year, sometimes indiscernible from the fall bloom. These patterns result from a combination of limiting environmental factors and interactions among planktonic groups with different optimal requirements. Simple models that represent the ecosystem with a single phytoplankton (P) and a single zooplankton (Z) group are challenged to reproduce these ecological interactions. Here we investigate the effect that added complexity has on determining spatio-temporal chlorophyll. We compare two ecosystem models, one that contains one P and one Z group, and one with two P and three Z groups. We consider three types of changes in complexity: 1) added dependencies among variables (e.g., temperature dependent rates), 2) modified structural pathways, and 3) added pathways. Subsets of the most sensitive parameters are optimized in each model to replicate observations in the region. For computational efficiency, the parameter optimization is performed using 1D surrogates of a 3D model. We evaluate how model complexity affects model skill, and whether the optimized parameter sets found for each model modify the interpretation of ecosystem functioning. Spatial differences in the parameter sets that best represent different areas hint at the existence of different ecological communities or at physical-biological interactions that are not represented in the simplest model. Our methodology emphasizes the combined use of observations, 1D models to help identifying patterns, and 3D models able to simulate the environment modre realistically, as a means to acquire predictive understanding of the ocean's ecology.

Niche construction, sources of selection and trait coevolution.

PubMed

Laland, Kevin; Odling-Smee, John; Endler, John

2017-10-06

Organisms modify and choose components of their local environments. This 'niche construction' can alter ecological processes, modify natural selection and contribute to inheritance through ecological legacies. Here, we propose that niche construction initiates and modifies the selection directly affecting the constructor, and on other species, in an orderly, directed and sustained manner. By dependably generating specific environmental states, niche construction co-directs adaptive evolution by imposing a consistent statistical bias on selection. We illustrate how niche construction can generate this evolutionary bias by comparing it with artificial selection. We suggest that it occupies the middle ground between artificial and natural selection. We show how the perspective leads to testable predictions related to: (i) reduced variance in measures of responses to natural selection in the wild; (ii) multiple trait coevolution, including the evolution of sequences of traits and patterns of parallel evolution; and (iii) a positive association between niche construction and biodiversity. More generally, we submit that evolutionary biology would benefit from greater attention to the diverse properties of all sources of selection.

Facilitating political decisions using species distribution models to assess restoration measures in heavily modified estuaries.

PubMed

Heuner, Maike; Weber, Arnd; Schröder, Uwe; Kleinschmit, Birgit; Schröder, Boris

2016-09-15

The European Water Framework Directive requires a good ecological potential for heavily modified water bodies. This standard has not been reached for most large estuaries by 2015. Management plans for estuaries fall short in linking implementations between restoration measures and underlying spatial analyses. The distribution of emergent macrophytes - as an indicator of habitat quality - is here used to assess the ecological potential. Emergent macrophytes are capable of settling on gentle tidal flats where hydrodynamic stress is comparatively low. Analyzing their habitats based on spatial data, we set up species distribution models with 'elevation relative to mean high water', 'mean bank slope', and 'length of bottom friction' from shallow water up to the vegetation belt as key predictors representing hydrodynamic stress. Effects of restoration scenarios on habitats were assessed applying these models. Our findings endorse species distribution models as crucial spatial planning tools for implementing restoration measures in modified estuaries. Copyright © 2016 Elsevier Ltd. All rights reserved.

Horizontal gene transfer between bacteria.

PubMed

Heuer, Holger; Smalla, Kornelia

2007-01-01

Horizontal gene transfer (HGT) refers to the acquisition of foreign genes by organisms. The occurrence of HGT among bacteria in the environment is assumed to have implications in the risk assessment of genetically modified bacteria which are released into the environment. First, introduced genetic sequences from a genetically modified bacterium could be transferred to indigenous micro-organisms and alter their genome and subsequently their ecological niche. Second, the genetically modified bacterium released into the environment might capture mobile genetic elements (MGE) from indigenous micro-organisms which could extend its ecological potential. Thus, for a risk assessment it is important to understand the extent of HGT and genome plasticity of bacteria in the environment. This review summarizes the present state of knowledge on HGT between bacteria as a crucial mechanism contributing to bacterial adaptability and diversity. In view of the use of GM crops and microbes in agricultural settings, in this mini-review we focus particularly on the presence and role of MGE in soil and plant-associated bacteria and the factors affecting gene transfer.

Spatially Explicit Landscape-Level Ecological Risks Induced by Land Use and Land Cover Change in a National Ecologically Representative Region in China.

PubMed

Gong, Jian; Yang, Jianxin; Tang, Wenwu

2015-11-09

Land use and land cover change is driven by multiple influential factors from environmental and social dimensions in a land system. Land use practices of human decision-makers modify the landscape of the land system, possibly leading to landscape fragmentation, biodiversity loss, or environmental pollution-severe environmental or ecological impacts. While landscape-level ecological risk assessment supports the evaluation of these impacts, investigations on how these ecological risks induced by land use practices change over space and time in response to alternative policy intervention remain inadequate. In this article, we conducted spatially explicit landscape ecological risk analysis in Ezhou City, China. Our study area is a national ecologically representative region experiencing drastic land use and land cover change, and is regulated by multiple policies represented by farmland protection, ecological conservation, and urban development. We employed landscape metrics to consider the influence of potential landscape-level disturbance for the evaluation of landscape ecological risks. Using spatiotemporal simulation, we designed scenarios to examine spatiotemporal patterns in landscape ecological risks in response to policy intervention. Our study demonstrated that spatially explicit landscape ecological risk analysis combined with simulation-driven scenario analysis is of particular importance for guiding the sustainable development of ecologically vulnerable land systems.

Spatially Explicit Landscape-Level Ecological Risks Induced by Land Use and Land Cover Change in a National Ecologically Representative Region in China

PubMed Central

Gong, Jian; Yang, Jianxin; Tang, Wenwu

2015-01-01

Land use and land cover change is driven by multiple influential factors from environmental and social dimensions in a land system. Land use practices of human decision-makers modify the landscape of the land system, possibly leading to landscape fragmentation, biodiversity loss, or environmental pollution—severe environmental or ecological impacts. While landscape-level ecological risk assessment supports the evaluation of these impacts, investigations on how these ecological risks induced by land use practices change over space and time in response to alternative policy intervention remain inadequate. In this article, we conducted spatially explicit landscape ecological risk analysis in Ezhou City, China. Our study area is a national ecologically representative region experiencing drastic land use and land cover change, and is regulated by multiple policies represented by farmland protection, ecological conservation, and urban development. We employed landscape metrics to consider the influence of potential landscape-level disturbance for the evaluation of landscape ecological risks. Using spatiotemporal simulation, we designed scenarios to examine spatiotemporal patterns in landscape ecological risks in response to policy intervention. Our study demonstrated that spatially explicit landscape ecological risk analysis combined with simulation-driven scenario analysis is of particular importance for guiding the sustainable development of ecologically vulnerable land systems. PMID:26569270

How Green Water Flows structure be a decision indicator for ecological water allocation in arid Ejina Delta, China.

NASA Astrophysics Data System (ADS)

Yu, J.; Du, C.; Zhang, Y.; Liu, X.

2014-12-01

Green water flows, a key ecohydrological process, dominates the hydrological cycle in arid region. The structure of green water flows reflects the landscape water consumption characteristics and can be easily obtained by means of remote sensing approach. In arid region, limited fresh water and fragile environment resulted in sharp contradictions between economy and natural ecosystem concerning water demands. To rationally allocate economic and ecological water use, to maximize the regional freshwater use efficiency, is the route one must take for sustainable development in arid area. The pursuit of the most necessary ecological protection function and the maximum ecological water use efficiency is the key to ecological water allocation. However, we are short of simple and quick detectable variables or indexes to assess ecological water allocation decision. This paper introduced the green water flows structure as a decision variable, chose Heihe river flow allocation to downstream Ejina Delta for ecological protection as an example, put forward why and how green water flows structure could be used for ecological water allocation decision. The authors expect to provide reference for integrated fresh water resources management practice in arid region.

The 2-MEV Scale in the United States: A Measure of Children's Environmental Attitudes Based on the Theory of Ecological Attitude

ERIC Educational Resources Information Center

Johnson, Bruce; Manoli, Constantinos C.

2011-01-01

The Environmental (2-MEV) Scale questionnaire was developed in Europe to measure adolescents' attitudes and gauge the effectiveness of educational programs. It also formed the basis for the Theory of Ecological Attitudes. In the present four-year study, the 2-MEV Scale was modified for use with 9-12-year-old children in the United States. Initial…

Do genetically modified plants impact arbuscular mycorrhizal fungi?

PubMed

Liu, Wenke

2010-02-01

The development and use of genetically modified plants (GMPs), as well as their ecological risks have been a topic of considerable public debate since they were first released in 1996. To date, no consistent conclusions have been drawn dealing with ecological risks on soil microorganisms of GMPs for the present incompatible empirical data. Arbuscular mycorrhizal fungi (AMF), important in regulating aboveground and underground processes in ecosystems, are the most crucial soil microbial community worthy of being monitored in ecological risks assessment of GMPs for their sensitivity to environmental alterations (plant, soil, climatic factor etc.). Based on current data, we suggest that there is a temporal-spatial relevance between expression and rhizosphere secretion of anti-disease and insecticidal proteins (e.g., Bt-Bacillus thuringiensis toxins) in and outer roots, and AMF intraradical and extraradical growth and development. Therefore, taking Bt transgenic plants (BTPs) for example, Bt insecticidal proteins constitutive expression and rhizosphere release during cultivation of BTPs may damage some critical steps of the AMF symbiotic development. More important, these processes of BTPs coincide with the entire life cycle of AMF annually, which may impact the diversity of AMF after long-term cultivation period. It is proposed that interactions between GMPs and AMF should be preferentially studied as an indicator for ecological impacts of GMPs on soil microbial communities. In this review, advances in impacts of GMPs on AMF and the effect mechanisms were summarized, highlighting the possible ecological implications of interactions between GMPs and AMF in soil ecosystems.

77 FR 13097 - Endangered Species; File Nos. 15661, 10027, and 15685

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-05

... population structure, size class composition, foraging ecology, and migration patterns for green and... of green and hawksbill sea turtles focusing on distribution and abundance, ecology, health, and... and population structure, foraging ecology, habitat use, and movements. Researchers may capture...

Taxonomic and ecological relevance of the chlorophyll a fluorescence signature of tree species in mixed European forests.

PubMed

Pollastrini, Martina; Holland, Vera; Brüggemann, Wolfgang; Bruelheide, Helge; Dănilă, Iulian; Jaroszewicz, Bogdan; Valladares, Fernando; Bussotti, Filippo

2016-10-01

The variability of chlorophyll a fluorescence (ChlF) parameters of forest tree species was investigated in 209 stands belonging to six European forests, from Mediterranean to boreal regions. The modifying role of environmental factors, forest structure and tree diversity (species richness and composition) on ChlF signature was analysed. At the European level, conifers showed higher potential performance than broadleaf species. Forests in central Europe performed better than those in Mediterranean and boreal regions. At the site level, homogeneous clusters of tree species were identified by means of a principal component analysis (PCA) of ChlF parameters. The discrimination of the clusters of species was influenced by their taxonomic position and ecological characteristics. The species richness influenced the tree ChlF properties in different ways depending on tree species and site. Tree species and site also affected the relationships between ChlF parameters and other plant functional traits (specific leaf area, leaf nitrogen content, light-saturated photosynthesis, wood density, leaf carbon isotope composition). The assessment of the photosynthetic properties of tree species, by means of ChlF parameters, in relation to their functional traits, is a relevant issue for studies in forest ecology. The connections of data from field surveys with remotely assessed parameters must be carefully explored. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

Socially acquired predator avoidance: is it just classical conditioning?

PubMed

Griffin, Andrea S

2008-06-15

Associative learning theories presume the existence of a general purpose learning process, the structure of which does not mirror the demands of any particular learning problem. In contrast, learning scientists working within an Evolutionary Biology tradition believe that learning processes have been shaped by ecological demands. One potential means of exploring how ecology may have modified properties of acquisition is to use associative learning theory as a framework within which to analyse a particular learning phenomenon. Recent work has used this approach to examine whether socially transmitted predator avoidance can be conceptualised as a classical conditioning process in which a novel predator stimulus acts as a conditioned stimulus (CS) and acquires control over an avoidance response after it has become associated with alarm signals of social companions, the unconditioned stimulus (US). I review here a series of studies examining the effect of CS/US presentation timing on the likelihood of acquisition. Results suggest that socially acquired predator avoidance may be less sensitive to forward relationships than traditional classical conditioning paradigms. I make the case that socially acquired predator avoidance is an exciting novel one-trial learning paradigm that could be studied along side fear conditioning. Comparisons between social and non-social learning of danger at both the behavioural and neural level may yield a better understanding of how ecology might shape properties and mechanisms of learning.

Predator attack rate evolution in space: the role of ecology mediated by complex emergent spatial structure and self-shading.

PubMed

Messinger, Susanna M; Ostling, Annette

2013-11-01

Predation interactions are an important element of ecological communities. Population spatial structure has been shown to influence predator evolution, resulting in the evolution of a reduced predator attack rate; however, the evolutionary role of traits governing predator and prey ecology is unknown. The evolutionary effect of spatial structure on a predator's attack rate has primarily been explored assuming a fixed metapopulation spatial structure, and understood in terms of group selection. But endogenously generated, emergent spatial structure is common in nature. Furthermore, the evolutionary influence of ecological traits may be mediated through the spatial self-structuring process. Drawing from theory on pathogens, the evolutionary effect of emergent spatial structure can be understood in terms of self-shading, where a voracious predator limits its long-term invasion potential by reducing local prey availability. Here we formalize the effects of self-shading for predators using spatial moment equations. Then, through simulations, we show that in a spatial context self-shading leads to relationships between predator-prey ecology and the predator's attack rate that are not expected in a non-spatial context. Some relationships are analogous to relationships already shown for host-pathogen interactions, but others represent new trait dimensions. Finally, since understanding the effects of ecology using existing self-shading theory requires simplifications of the emergent spatial structure that do not apply well here, we also develop metrics describing the complex spatial structure of the predator and prey populations to help us explain the evolutionary effect of predator and prey ecology in the context of self-shading. The identification of these metrics may provide a step towards expansion of the predictive domain of self-shading theory to more complex spatial dynamics. Copyright © 2013 Elsevier Inc. All rights reserved.

Salvage logging, ecosystem processes, and biodiversity conservation.

PubMed

Lindenmayer, D B; Noss, R F

2006-08-01

We summarize the documented and potential impacts of salvage logging--a form of logging that removes trees and other biological material from sites after natural disturbance. Such operations may reduce or eliminate biological legacies, modify rare postdisturbance habitats, influence populations, alter community composition, impair natural vegetation recovery, facilitate the colonization of invasive species, alter soil properties and nutrient levels, increase erosion, modify hydrological regimes and aquatic ecosystems, and alter patterns of landscape heterogeneity These impacts can be assigned to three broad and interrelated effects: (1) altered stand structural complexity; (2) altered ecosystem processes and functions; and (3) altered populations of species and community composition. Some impacts may be different from or additional to the effects of traditional logging that is not preceded by a large natural disturbance because the conditions before, during, and after salvage logging may differ from those that characterize traditional timber harvesting. The potential impacts of salvage logging often have been overlooked, partly because the processes of ecosystem recovery after natural disturbance are still poorly understood and partly because potential cumulative effects of natural and human disturbance have not been well documented. Ecologically informed policies regarding salvage logging are needed prior to major natural disturbances so that when they occur ad hoc and crisis-mode decision making can be avoided. These policies should lead to salvage-exemption zones and limits on the amounts of disturbance-derived biological legacies (e.g., burned trees, logs) that are removed where salvage logging takes place. Finally, we believe new terminology is needed. The word salvage implies that something is being saved or recovered, whereas from an ecological perspective this is rarely the case.

Spatial transferring of ecosystem services and property rights allocation of ecological compensation

NASA Astrophysics Data System (ADS)

Wen, Wujun; Xu, Geng; Wang, Xingjie

2011-09-01

Ecological compensation is an important means to maintain the sustainability and stability of ecosystem services. The property rights analysis of ecosystem services is indispensable when we implement ecological compensation. In this paper, ecosystem services are evaluated via spatial transferring and property rights analysis. Take the Millennium Ecosystem Assessment (MA) as an example, we attempt to classify the spatial structure of 31 categories of ecosystem services into four dimensions, i.e., local, regional, national and global ones, and divide the property rights structure into three types, i.e., private property rights, common property rights and state-owned property rights. Through the case study of forestry, farming industry, drainage area, development of mineral resources, nature reserves, functional areas, agricultural land expropriation, and international cooperation on ecological compensation, the feasible ecological compensation mechanism is illustrated under the spatial structure and property rights structure of the concerned ecosystem services. For private property rights, the ecological compensation mode mainly depends on the market mechanism. If the initial common property rights are "hidden," the implementation of ecological compensation mainly relies on the quota market transactions and the state investment under the state-owned property rights, and the fairness of property rights is thereby guaranteed through central administration.

It is all about location: how to pinpoint microorganisms and their functions in multispecies biofilms.

PubMed

Costa, Angela M; Mergulhão, Filipe J; Briandet, Romain; Azevedo, Nuno F

2017-09-01

Multispecies biofilms represent the dominant mode of life for the vast majority of microorganisms. Bacterial spatial localization in such biostructures governs ecological interactions between different populations and triggers the overall community functions. Here, we discuss the pros and cons of fluorescence-based techniques used to decipher bacterial species patterns in biofilms at single cell level, including fluorescence in situ hybridization and the use of genetically modified bacteria that express fluorescent proteins, reporting the significant improvements of those techniques. The development of tools for spatial and temporal study of multispecies biofilms will allow live imaging and spatial localization of cells in naturally occurring biofilms coupled with metabolic information, increasing insight of microbial community and the relation between its structure and functions.

Conceptualizing and communicating ecological river restoration: Chapter 2

USGS Publications Warehouse

Jacobson, Robert B.; Berkley, Jim

2011-01-01

We present a general conceptual model for communicating aspects of river restoration and management. The model is generic and adaptable to most riverine settings, independent of size. The model has separate categories of natural and social-economic drivers, and management actions are envisioned as modifiers of naturally dynamic systems. The model includes a decision-making structure in which managers, stakeholders, and scientists interact to define management objectives and performance evaluation. The model depicts a stress to the riverine ecosystem as either (1) deviation in the regimes (flow, sediment, temperature, light, biogeochemical, and genetic) by altering the frequency, magnitude, duration, timing, or rate of change of the fluxes or (2) imposition of a hard structural constraint on channel form. Restoration is depicted as naturalization of those regimes or removal of the constraint. The model recognizes the importance of river history in conditioning future responses. Three hierarchical tiers of essential ecosystem characteristics (EECs) illustrate how management actions typically propagate through physical/chemical processes to habitat to biotic responses. Uncertainty and expense in modeling or measuring responses increase in moving from tiers 1 to 3. Social-economic characteristics are shown in a parallel structure that emphasizes the need to quantify trade-offs between ecological and social-economic systems. Performance measures for EECs are also hierarchical, showing that selection of measures depend on participants’ willingness to accept uncertainty. The general form is of an adaptive management loop in which the performance measures are compared to reference conditions or success criteria and the information is fed back into the decision-making process.

Indirect effects of ecosystem engineering combine with consumer behaviour to determine the spatial distribution of herbivory.

PubMed

Griffen, Blaine D; Riley, Megan E; Cannizzo, Zachary J; Feller, Ilka C

2017-10-01

Ecosystem engineers alter environments by creating, modifying or destroying habitats. The indirect impacts of ecosystem engineering on trophic interactions should depend on the combination of the spatial distribution of engineered structures and the foraging behaviour of consumers that use these structures as refuges. In this study, we assessed the indirect effects of ecosystem engineering by a wood-boring beetle in a neotropical mangrove forest system. We identified herbivory patterns in a dwarf mangrove forest on the archipelago of Twin Cays, Belize. Past wood-boring activity impacted more than one-third of trees through the creation of tree holes that are now used, presumably as predation or thermal refuge, by the herbivorous mangrove tree crab Aratus pisonii. The presence of these refuges had a significant impact on plant-animal interactions; herbivory was more than fivefold higher on trees influenced by tree holes relative to those that were completely isolated from these refuges. Additionally, herbivory decreased exponentially with increasing distance from tree holes. We use individual-based simulation modelling to demonstrate that the creation of these herbivory patterns depends on a combination of the use of engineered tree holes for refuge by tree crabs, and the use of two behaviour patterns in this species-site fidelity to a "home tree," and more frequent foraging near their home tree. We demonstrate that understanding the spatial distribution of herbivory in this system depends on combining both the use of ecosystem engineering structures with individual behavioural patterns of herbivores. © 2017 The Authors. Journal of Animal Ecology © 2017 British Ecological Society.

Integrated structural biology and molecular ecology of N-cycling enzymes from ammonia-oxidizing archaea

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

Tolar, Bradley B.; Herrmann, Jonathan; Bargar, John R.

In this paper, knowledge of the molecular ecology and environmental determinants of ammonia-oxidizing organisms is critical to understanding and predicting the global nitrogen (N) and carbon cycles, but an incomplete biochemical picture hinders in vitro studies of N-cycling enzymes. Although an integrative structural and dynamic characterization at the atomic scale would advance our understanding of function tremendously, structural knowlede of key N-cycling enzymes from ecologically-relevant ammonia oxidizers is unfortunately extremely limited. Here, we discuss the challenges and opportunities for examining the ecology of ammonia-oxidizing organisms, particularly uncultivated Thaumarchaeota, though (meta)genome-driven structural biology of the enzymes ammonia monooxygenase (AMO) andmore » nitrite reductase (NirK).« less

Integrated structural biology and molecular ecology of N-cycling enzymes from ammonia-oxidizing archaea

DOE PAGES

Tolar, Bradley B.; Herrmann, Jonathan; Bargar, John R.; ...

2017-07-05

In this paper, knowledge of the molecular ecology and environmental determinants of ammonia-oxidizing organisms is critical to understanding and predicting the global nitrogen (N) and carbon cycles, but an incomplete biochemical picture hinders in vitro studies of N-cycling enzymes. Although an integrative structural and dynamic characterization at the atomic scale would advance our understanding of function tremendously, structural knowlede of key N-cycling enzymes from ecologically-relevant ammonia oxidizers is unfortunately extremely limited. Here, we discuss the challenges and opportunities for examining the ecology of ammonia-oxidizing organisms, particularly uncultivated Thaumarchaeota, though (meta)genome-driven structural biology of the enzymes ammonia monooxygenase (AMO) andmore » nitrite reductase (NirK).« less

Integrated structural biology and molecular ecology of N-cycling enzymes from ammonia-oxidizing archaea.

PubMed

Tolar, Bradley B; Herrmann, Jonathan; Bargar, John R; van den Bedem, Henry; Wakatsuki, Soichi; Francis, Christopher A

2017-10-01

Knowledge of the molecular ecology and environmental determinants of ammonia-oxidizing organisms is critical to understanding and predicting the global nitrogen (N) and carbon cycles, but an incomplete biochemical picture hinders in vitro studies of N-cycling enzymes. Although an integrative structural and dynamic characterization at the atomic scale would advance our understanding of function tremendously, structural knowledge of key N-cycling enzymes from ecologically relevant ammonia oxidizers is unfortunately extremely limited. Here, we discuss the challenges and opportunities for examining the ecology of ammonia-oxidizing organisms, particularly uncultivated Thaumarchaeota, through (meta)genome-driven structural biology of the enzymes ammonia monooxygenase (AMO) and nitrite reductase (NirK). © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

Rivers are social–ecological systems: Time to integrate human dimensions into riverscape ecology and management

USGS Publications Warehouse

Dunham, Jason B.; Angermeier, Paul L.; Crausbay, Shelley D.; Cravens, Amanda; Gosnell, Hannah; McEvoy, Jamie; Moritz, Max A.; Raheem, Nejem; Sanford, Todd

2018-01-01

Incorporation of concepts from landscape ecology into understanding and managing riverine ecosystems has become widely known as riverscape ecology. Riverscape ecology emphasizes interactions among processes at different scales and their consequences for valued ecosystem components, such as riverine fishes. Past studies have focused strongly on understanding the ecological processes in riverscapes and how human actions modify those processes. It is increasingly clear, however, that an understanding of the drivers behind actions that lead to human modification also merit consideration, especially regarding how those drivers influence management efficacy. These indirect drivers of riverscape outcomes can be understood in the context of a diverse array of social processes, which we collectively refer to as human dimensions. Like ecological phenomena, social processes also exhibit complex interactions across spatiotemporal scales. Greater emphasis on feedbacks between social and ecological processes will lead scientists and managers to more completely understand riverscapes as complex, dynamic, interacting social–ecological systems. Emerging applications in riverscapes, as well as studies of other ecosystems, provide examples that can lead to stronger integration of social and ecological science. We argue that conservation successes within riverscapes may not come from better ecological science, improved ecosystem service analyses, or even economic incentives if the fundamental drivers of human behaviors are not understood and addressed in conservation planning and implementation.

40 CFR 230.75 - Actions affecting plant and animal populations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... restoration to produce a new or modified environmental state of higher ecological value by displacement of...; (c) Avoiding sites having unique habitat or other value, including habitat of threatened or...

Human niche construction in interdisciplinary focus

PubMed Central

Kendal, Jeremy; Tehrani, Jamshid J.; Odling-Smee, John

2011-01-01

Niche construction is an endogenous causal process in evolution, reciprocal to the causal process of natural selection. It works by adding ecological inheritance, comprising the inheritance of natural selection pressures previously modified by niche construction, to genetic inheritance in evolution. Human niche construction modifies selection pressures in environments in ways that affect both human evolution, and the evolution of other species. Human ecological inheritance is exceptionally potent because it includes the social transmission and inheritance of cultural knowledge, and material culture. Human genetic inheritance in combination with human cultural inheritance thus provides a basis for gene–culture coevolution, and multivariate dynamics in cultural evolution. Niche construction theory potentially integrates the biological and social aspects of the human sciences. We elaborate on these processes, and provide brief introductions to each of the papers published in this theme issue. PMID:21320894

On the Half Shell: An Introduction to Oysters and Their Unique Structures and Function

ERIC Educational Resources Information Center

Frederick, J. Adam; Haines, Sarah; Romano, Christina; Takacs, Jacqueline

2017-01-01

The eastern oyster, "Crassostrea virginica," is an ecologically and economically important species in Chesapeake Bay. Oysters are ecologically unique in the Chesapeake Bay because they build a structure known as a bar or reef by attaching to one another over a 45 long period of time. They have been coined the "Ecological Engineers…

Determination of Secondary School Students' Cognitive Structure, and Misconception in Ecological Concepts through Word Association Test

ERIC Educational Resources Information Center

Yücel, Elif Özata; Özkan, Mulis

2015-01-01

In this study, we determined cognitive structures and misconceptions about basic ecological concepts by using "word association" tests on secondary school students, age between 12-14 years. Eighty-nine students participated in this study. Before WAT was generated, basic ecological concepts that take place in the secondary science…

Linking extinction-colonization dynamics to genetic structure in a salamander metapopulation.

PubMed

Cosentino, Bradley J; Phillips, Christopher A; Schooley, Robert L; Lowe, Winsor H; Douglas, Marlis R

2012-04-22

Theory predicts that founder effects have a primary role in determining metapopulation genetic structure. However, ecological factors that affect extinction-colonization dynamics may also create spatial variation in the strength of genetic drift and migration. We tested the hypothesis that ecological factors underlying extinction-colonization dynamics influenced the genetic structure of a tiger salamander (Ambystoma tigrinum) metapopulation. We used empirical data on metapopulation dynamics to make a priori predictions about the effects of population age and ecological factors on genetic diversity and divergence among 41 populations. Metapopulation dynamics of A. tigrinum depended on wetland area, connectivity and presence of predatory fish. We found that newly colonized populations were more genetically differentiated than established populations, suggesting that founder effects influenced genetic structure. However, ecological drivers of metapopulation dynamics were more important than age in predicting genetic structure. Consistent with demographic predictions from metapopulation theory, genetic diversity and divergence depended on wetland area and connectivity. Divergence was greatest in small, isolated wetlands where genetic diversity was low. Our results show that ecological factors underlying metapopulation dynamics can be key determinants of spatial genetic structure, and that habitat area and isolation may mediate the contributions of drift and migration to divergence and evolution in local populations.

Fragmentation and Isolation

EPA Science Inventory

Landscapes are being modified by humans at ever-increasing rates worldwide. This landscape level modification has resulted in changes in ecological patterns and processes, including species distributions. The rate at which humans are altering both terrestrial and aquatic habitats...

Using ecological thresholds to evaluate the costs and benefits of set-asides in a biodiversity hotspot.

PubMed

Banks-Leite, Cristina; Pardini, Renata; Tambosi, Leandro R; Pearse, William D; Bueno, Adriana A; Bruscagin, Roberta T; Condez, Thais H; Dixo, Marianna; Igari, Alexandre T; Martensen, Alexandre C; Metzger, Jean Paul

2014-08-29

Ecological set-asides are a promising strategy for conserving biodiversity in human-modified landscapes; however, landowner participation is often precluded by financial constraints. We assessed the ecological benefits and economic costs of paying landowners to set aside private land for restoration. Benefits were calculated from data on nearly 25,000 captures of Brazilian Atlantic Forest vertebrates, and economic costs were estimated for several restoration scenarios and values of payment for ecosystem services. We show that an annual investment equivalent to 6.5% of what Brazil spends on agricultural subsidies would revert species composition and ecological functions across farmlands to levels found inside protected areas, thereby benefiting local people. Hence, efforts to secure the future of this and other biodiversity hotspots may be cost-effective. Copyright © 2014, American Association for the Advancement of Science.

The effect of social alliances on wolf population on their survival under hunting

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

Cebrat, S.; Kakol, J.

1997-04-01

We have introduced the modified Verhulst factor to simulate the dynamics of wolves` population. The new factor enlarges the capacity of environment for organisms living in organized groups. Under this factor, social behavior allows the population to reach the larger size in the same ecological niche. The other effect of the introduced factor is that additional non-selective killing factors limit the population size not only directly but also by shrinking the effective ecological niche capacity.

The Effect of Social Alliances on Wolf Population on Their Survival Under Hunting

NASA Astrophysics Data System (ADS)

Cebrat, Stanisław; Kakol, Jerzy

We have introduced the modified Verhulst factor to simulate the dynamics of wolves' population. The new factor enlarges the capacity of environment for organisms living in organized groups. Under this factor, social behavior allows the population to reach the larger size in the same ecological niche. The other effect of the introduced factor is that additional non-selective killing factors limit the population size not only directly but also by shrinking the effective ecological niche capacity.

Applications of fractals in ecology.

PubMed

Sugihara, G; M May, R

1990-03-01

Fractal models describe the geometry of a wide variety of natural objects such as coastlines, island chains, coral reefs, satellite ocean-color images and patches of vegetation. Cast in the form of modified diffusion models, they can mimic natural and artificial landscapes having different types of complexity of shape. This article provides a brief introduction to fractals and reports on how they can be used by ecologists to answer a variety of basic questions, about scale, measurement and hierarchy in, ecological systems. Copyright © 1990. Published by Elsevier Ltd.

Neutral Community Dynamics and the Evolution of Species Interactions.

PubMed

Coelho, Marco Túlio P; Rangel, Thiago F

2018-04-01

A contemporary goal in ecology is to determine the ecological and evolutionary processes that generate recurring structural patterns in mutualistic networks. One of the great challenges is testing the capacity of neutral processes to replicate observed patterns in ecological networks, since the original formulation of the neutral theory lacks trophic interactions. Here, we develop a stochastic-simulation neutral model adding trophic interactions to the neutral theory of biodiversity. Without invoking ecological differences among individuals of different species, and assuming that ecological interactions emerge randomly, we demonstrate that a spatially explicit multitrophic neutral model is able to capture the recurrent structural patterns of mutualistic networks (i.e., degree distribution, connectance, nestedness, and phylogenetic signal of species interactions). Nonrandom species distribution, caused by probabilistic events of migration and speciation, create nonrandom network patterns. These findings have broad implications for the interpretation of niche-based processes as drivers of ecological networks, as well as for the integration of network structures with demographic stochasticity.

[Construction and evaluation of ecological network in Poyang Lake Eco-economic Zone, China.

PubMed

Chen, Xiao Ping; Chen, Wen Bo

2016-05-01

Large-scale ecological patches play an important role in regional biodiversity conservation. However, with the rapid progress of China's urbanization, human disturbance on the environment is becoming stronger. Large-scale ecological patches will degrade not only in quantity, but also in quality, threatening the connections among them due to isolation and seriously affecting the biodiversity protection. Taking Poyang Lake Eco-economic Zone as a case, this paper established the potential ecological corridors by minimum cost model and GIS technique taking the impacts of landscape types, slope and human disturbance into consideration. Then, based on gravity quantitative model, we analyzed the intensity of ecological interactions between patches, and the potential ecological corridors were divided into two classes for sake of protection. Finally, the important ecological nodes and breaking points were identified, and the structure of the potential ecological network was analyzed. The results showed that forest and cropland were the main landscape types of ecological corridor composition, interaction between ecological patches differed obviously and the structure of the composed regional ecological network was complex with high connectivity and closure. It might provide a scientific basis for the protection of biodiversity and ecological network optimization in Poyang Lake Eco-economic Zone.

[Delineation of ecological security pattern based on ecological network].

PubMed

Fu, Qiang; Gu, Chao Lin

2017-03-18

Ecological network can be used to describe and assess the relationship between spatial organization of landscapes and species survival under the condition of the habitat fragmentation. Taking Qingdao City as the research area, woodland and wetland ecological networks in 2005 were simulated based on least cost path method, and the ecological networks were classified by their corridors' cumulative cost value. We made importance distinction of ecological network structure elements such as patches and corridors using betweenness centrality index and correlation length-percentage of importance of omitted patches index, and then created the structure system of ecological network. Considering the effects brought by the newly-added construction land from 2005 to 2013, we proposed the ecological security pattern for construction land change of Qingdao City. The results showed that based on ecological network framework, graph theory based methods could be used to quantify both attributes of specific ecological land (e.g., the area of an ecological network patch) and functional connection between ecological lands. Between 2005 and 2013, large area of wetlands had been destroyed by newly-added construction land, while the role of specific woodland and wetland played in the connection of the whole network had not been considered. The delineation of ecological security pattern based on ecological network could optimize regional ecological basis, provide accurate spatial explicit decision for ecological conservation and restoration, and meanwhile provide scientific and reasonable space guidance for urban spatial expansion.

Ecological forestry in an uneven-aged, late-successional forest: Simulated effects of contrasting treatments on structure and yield

Treesearch

Jacob J. Hanson; Craig G. Lorimer; Corey R. Halpin; Brian J. Palik

2012-01-01

Ecological forestry practices are designed to retain species and structural features important for maintaining ecosystem function but which may be deficient in conventionally managed stands. We used the spatially-explicit, individual tree model CANOPY to assess tradeoffs in enhanced ecological attributes vs. reductions in timber yield for a wide variety of treatments...

Taking a systems approach to ecological systems

USGS Publications Warehouse

Grace, James B.

2015-01-01

Increasingly, there is interest in a systems-level understanding of ecological problems, which requires the evaluation of more complex, causal hypotheses. In this issue of the Journal of Vegetation Science, Soliveres et al. use structural equation modeling to test a causal network hypothesis about how tree canopies affect understorey communities. Historical analysis suggests structural equation modeling has been under-utilized in ecology.

Fire modifies the phylogenetic structure of soil bacterial co-occurrence networks.

PubMed

Pérez-Valera, Eduardo; Goberna, Marta; Faust, Karoline; Raes, Jeroen; García, Carlos; Verdú, Miguel

2017-01-01

Fire alters ecosystems by changing the composition and community structure of soil microbes. The phylogenetic structure of a community provides clues about its main assembling mechanisms. While environmental filtering tends to reduce the community phylogenetic diversity by selecting for functionally (and hence phylogenetically) similar species, processes like competitive exclusion by limiting similarity tend to increase it by preventing the coexistence of functionally (and phylogenetically) similar species. We used co-occurrence networks to detect co-presence (bacteria that co-occur) or exclusion (bacteria that do not co-occur) links indicative of the ecological interactions structuring the community. We propose that inspecting the phylogenetic structure of co-presence or exclusion links allows to detect the main processes simultaneously assembling the community. We monitored a soil bacterial community after an experimental fire and found that fire altered its composition, richness and phylogenetic diversity. Both co-presence and exclusion links were more phylogenetically related than expected by chance. We interpret such a phylogenetic clustering in co-presence links as a result of environmental filtering, while that in exclusion links reflects competitive exclusion by limiting similarity. This suggests that environmental filtering and limiting similarity operate simultaneously to assemble soil bacterial communities, widening the traditional view that only environmental filtering structures bacterial communities. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

Evaluation of DGVMs in tropical areas: linking patterns of vegetation cover, climate and fire to ecological processes

NASA Astrophysics Data System (ADS)

D'Onofrio, Donatella; von Hardenberg, Jost; Baudena, Mara

2017-04-01

Many current Dynamic Global Vegetation Models (DGVMs), including those incorporated into Earth System Models (ESMs), are able to realistically reproduce the distribution of the most worldwide biomes. However, they display high uncertainty in predicting the forest, savanna and grassland distributions and the transitions between them in tropical areas. These biomes are the most productive terrestrial ecosystems, and owing to their different biogeophysical and biogeochemical characteristics, future changes in their distributions could have also impacts on climate states. In particular, expected increasing temperature and CO2, modified precipitation regimes, as well as increasing land-use intensity could have large impacts on global biogeochemical cycles and precipitation, affecting the land-climate interactions. The difficulty of the DGVMs in simulating tropical vegetation, especially savanna structure and occurrence, has been associated with the way they represent the ecological processes and feedbacks between biotic and abiotic conditions. The inclusion of appropriate ecological mechanisms under present climatic conditions is essential for obtaining reliable future projections of vegetation and climate states. In this work we analyse observed relationships of tree and grass cover with climate and fire, and the current ecological understanding of the mechanisms driving the forest-savanna-grassland transition in Africa to evaluate the outcomes of a current state-of-the-art DGVM and to assess which ecological processes need to be included or improved within the model. Specifically, we analyse patterns of woody and herbaceous cover and fire return times from MODIS satellite observations, rainfall annual average and seasonality from TRMM satellite measurements and tree phenology information from the ESA global land cover map, comparing them with the outcomes of the LPJ-GUESS DGVM, also used by the EC-Earth global climate model. The comparison analysis with the LPJ-GUESS simulations suggests possible improvements in the model representations of tree-grass competition for water and in the vegetation-fire interaction. The proposed method could be useful for evaluating DGVMs in tropical areas, especially in the phase of model setting-up, before the coupling with Earth System Models. This could help in improving the simulations of ecological processes and consequently of land-climate interactions.

[Constructing ecological security patterns in mountain areas based on geological disaster sensitivity: A case study in Yuxi City, Yunnan Province, China.

PubMed

Peng, Jian; Guo, Xiao Nan; Hu, Yi Na; Liu, Yan Xu

2017-02-01

As one of the key topics in the research of landscape ecology, regional ecological security patterns can effectively promote regional sustainable development and terrestrial ecological barriers construction. It is extremely important for middle Yunnan, with frequent disasters and fragile ecolo-gical environment, to construct ecological security patterns so as to effectively avoid the geological disasters, maintain ecosystem health, and promote the coordinated development of regional ecological system and social economic system. Taking Yuxi City as a case study area, this study firstly estimated the ecosystem services importance of water conservation, carbon fixation and oxygen release, soil conservation, and biodiversity according to the basal characteristics of regional ecological environment, and then identified ecological sources in consideration of the quality of integrated ecosystem services and single types. Secondly, the resistance surface based on land use types was modified by the sensitivity of regional geological disasters. Lastly, the ecological corridors were identified using minimum cumulative resistance model, and as a result, the ecological security pattern of Yuxi City was constructed. The results showed that there were 81 patches for ecological sources in Yuxi City, accounting for 38.4% of the total area, and overlaying 75.2% of nature protection areas. The ecological sources were mainly distributed in the western mountainous areas as well as eastern water areas of the city. The length of ecological corridors was 1642.04 km, presenting a spatial pattern of one vertical and three horizontals, and extending along river valleys and fault basins with high vegetation coverage. This paper constructed ecological security patterns in mountainous areas aiming at the characteristics of geological disasters, providing spatial guidance for development and conservation decision-making in mountain areas.

Environmental release of living modified organisms: current approaches and case studies.

PubMed

Thomas, E; Nickson, Ph D

2005-01-01

Agricultural biotechnology is being rapidly adopted as evidenced by the acreage of genetically modified (GM) crops planted and tonnes of product (grain and fiber) harvested. Concurrent with this technological progress, is a growing concern that the worlds biological diversity is coming under increasing threat from human activities. As such, ecological risk assessment approaches are being developed for GM crop plants as international agreements regulating the transboundary movements of these products are being implemented. This paper reviews the ecological risk assessment approach that has been used to date to approve GM crops to date. The process has been case-by-case, using a comparative, science-based approach balancing the potential risks and benefits of the new technology versus those present with the currently accepted practices. The approach used to evaluate and approve these products is consistent with the conditions and requirements outlined in the Cartagena Protocol.

The effect of climatic forcing on population synchrony and genetic structuring of the Canadian lynx

PubMed Central

Stenseth, Nils Chr.; Ehrich, Dorothee; Rueness, Eli Knispel; Lingjærde, Ole Chr.; Chan, Kung-Sik; Boutin, Stan; O'Donoghue, Mark; Robinson, David A.; Viljugrein, Hildegunn; Jakobsen, Kjetill S.

2004-01-01

The abundance of Canadian lynx follows 10-year density fluctuations across the Canadian subcontinent. These cyclic fluctuations have earlier been shown to be geographically structured into three climatic regions: the Atlantic, Continental, and Pacific zones. Recent genetic evidence revealed an essentially similar spatial structuring. Introducing a new population model, the “climate forcing of ecological and evolutionary patterns” model, we link the observed ecological and evolutionary patterns. Specifically, we demonstrate that there is greater phase synchrony within climatic zones than between them and show that external climatic forcing may act as a synchronizer. We simulated genetic drift by using data on population dynamics generated by the climate forcing of ecological and evolutionary patterns model, and we demonstrate that the observed genetic structuring can be seen as an emerging property of the spatiotemporal ecological dynamics. PMID:15067131

Ecology and evolution of plant–pollinator interactions

PubMed Central

Mitchell, Randall J.; Irwin, Rebecca E.; Flanagan, Rebecca J.; Karron, Jeffrey D.

2009-01-01

Background Some of the most exciting advances in pollination biology have resulted from interdisciplinary research combining ecological and evolutionary perspectives. For example, these two approaches have been essential for understanding the functional ecology of floral traits, the dynamics of pollen transport, competition for pollinator services, and patterns of specialization and generalization in plant–pollinator interactions. However, as research in these and other areas has progressed, many pollination biologists have become more specialized in their research interests, focusing their attention on either evolutionary or ecological questions. We believe that the continuing vigour of a synthetic and interdisciplinary field like pollination biology depends on renewed connections between ecological and evolutionary approaches. Scope In this Viewpoint paper we highlight the application of ecological and evolutionary approaches to two themes in pollination biology: (1) links between pollinator behaviour and plant mating systems, and (2) generalization and specialization in pollination systems. We also describe how mathematical models and synthetic analyses have broadened our understanding of pollination biology, especially in human-modified landscapes. We conclude with several suggestions that we hope will stimulate future research. This Viewpoint also serves as the introduction to this Special Issue on the Ecology and Evolution of Plant–Pollinator Interactions. These papers provide inspiring examples of the synergy between evolutionary and ecological approaches, and offer glimpses of great accomplishments yet to come. PMID:19482881

Ecology and evolution of plant-pollinator interactions.

PubMed

Mitchell, Randall J; Irwin, Rebecca E; Flanagan, Rebecca J; Karron, Jeffrey D

2009-06-01

Some of the most exciting advances in pollination biology have resulted from interdisciplinary research combining ecological and evolutionary perspectives. For example, these two approaches have been essential for understanding the functional ecology of floral traits, the dynamics of pollen transport, competition for pollinator services, and patterns of specialization and generalization in plant-pollinator interactions. However, as research in these and other areas has progressed, many pollination biologists have become more specialized in their research interests, focusing their attention on either evolutionary or ecological questions. We believe that the continuing vigour of a synthetic and interdisciplinary field like pollination biology depends on renewed connections between ecological and evolutionary approaches. In this Viewpoint paper we highlight the application of ecological and evolutionary approaches to two themes in pollination biology: (1) links between pollinator behaviour and plant mating systems, and (2) generalization and specialization in pollination systems. We also describe how mathematical models and synthetic analyses have broadened our understanding of pollination biology, especially in human-modified landscapes. We conclude with several suggestions that we hope will stimulate future research. This Viewpoint also serves as the introduction to this Special Issue on the Ecology and Evolution of Plant-Pollinator Interactions. These papers provide inspiring examples of the synergy between evolutionary and ecological approaches, and offer glimpses of great accomplishments yet to come.

Sex-specific triacylglycerides are widely conserved in Drosophila and mediate mating behavior

PubMed Central

Chin, Jacqueline SR; Ellis, Shane R; Pham, Huong T; Blanksby, Stephen J; Mori, Kenji; Koh, Qi Ling; Etges, William J; Yew, Joanne Y

2014-01-01

Pheromones play an important role in the behavior, ecology, and evolution of many organisms. The structure of many insect pheromones typically consists of a hydrocarbon backbone, occasionally modified with various functional oxygen groups. Here we show that sex-specific triacylclyerides (TAGs) are broadly conserved across the subgenus Drosophila in 11 species and represent a novel class of pheromones that has been largely overlooked. In desert-adapted drosophilids, 13 different TAGs are secreted exclusively by males from the ejaculatory bulb, transferred to females during mating, and function synergistically to inhibit courtship from other males. Sex-specific TAGs are comprised of at least one short branched tiglic acid and a long linear fatty acyl component, an unusual structural motif that has not been reported before in other natural products. The diversification of chemical cues used by desert-adapted Drosophila as pheromones may be related to their specialized diet of fermenting cacti. DOI: http://dx.doi.org/10.7554/eLife.01751.001 PMID:24618898

Designing agricultural landscapes for biodiversity-based ecosystem services

DOE PAGES

Landis, Douglas A.

2016-07-28

Sustainable and resilient agricultural systems are needed to feed and fuel a growing human population. However, the current model of agricultural intensification which produces high yields has also resulted in a loss of biodiversity, ecological function, and critical ecosystem services in agricultural landscapes. A key consequence of agricultural intensification is landscape simplification, where once heterogeneous landscapes contain increasingly fewer crop and non-crop habitats. Landscape simplification exacerbates biodiversity losses which leads to reductions in ecosystem services on which agriculture depends. In recent decades, considerable research has focused on mitigating these negative impacts, primarily via management of habitats to promote biodiversity andmore » enhance services at the local scale. While it is well known that local and landscape factors interact, modifying overall landscape structure is seldom considered due to logistical constraints. Here, I propose that the loss of ecosystem services due to landscape simplification can only be addressed by a concerted effort to fundamentally redesign agricultural landscapes. Designing agricultural landscapes will require that scientists work with stakeholders to determine the mix of desired ecosystem services, evaluate current landscape structure in light of those goals, and implement targeted modifications to achieve them. I evaluate the current status of landscape design, ranging from fundamental ecological principles to resulting guidelines and socioeconomic tools. Finally, while research gaps remain, the time is right for ecologists to engage with other disciplines, stakeholders, and policymakers in education and advocacy to foster agricultural landscape design for sustainable and resilient biodiversity services.« less

Designing agricultural landscapes for biodiversity-based ecosystem services

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

Landis, Douglas A.

Sustainable and resilient agricultural systems are needed to feed and fuel a growing human population. However, the current model of agricultural intensification which produces high yields has also resulted in a loss of biodiversity, ecological function, and critical ecosystem services in agricultural landscapes. A key consequence of agricultural intensification is landscape simplification, where once heterogeneous landscapes contain increasingly fewer crop and non-crop habitats. Landscape simplification exacerbates biodiversity losses which leads to reductions in ecosystem services on which agriculture depends. In recent decades, considerable research has focused on mitigating these negative impacts, primarily via management of habitats to promote biodiversity andmore » enhance services at the local scale. While it is well known that local and landscape factors interact, modifying overall landscape structure is seldom considered due to logistical constraints. Here, I propose that the loss of ecosystem services due to landscape simplification can only be addressed by a concerted effort to fundamentally redesign agricultural landscapes. Designing agricultural landscapes will require that scientists work with stakeholders to determine the mix of desired ecosystem services, evaluate current landscape structure in light of those goals, and implement targeted modifications to achieve them. I evaluate the current status of landscape design, ranging from fundamental ecological principles to resulting guidelines and socioeconomic tools. Finally, while research gaps remain, the time is right for ecologists to engage with other disciplines, stakeholders, and policymakers in education and advocacy to foster agricultural landscape design for sustainable and resilient biodiversity services.« less

Hedge your bets on Flood Risk: How do Hedgerows modify hillslope and catchment scale hydrological response?

NASA Astrophysics Data System (ADS)

Coates, Victoria; Pattison, Ian

2017-04-01

A dominant feature in the agricultural landscape in the UK are field boundaries. Two thirds of England has been continuously hedged for over a thousand years although most modern hedges were planted during the Enclosures Acts 1720-1840. However, the use of larger agricultural machinery has resulted in the removal of some field boundaries and the subsequent increase in field sizes over the 20th Century. The multiple benefits of hedgerows in ecology have been extensively studied, but the impact of these widespread features on hydrology and flood risk has seen very little attention. Nature-based solutions are increasingly being seen as a complementary approach to hard engineered flood defences. It is hypothesised that hedgerows play a part in this through modifying hillslope hydrological processes, including (a) changing the spatial distribution of precipitation due to sheltering effects; (b) biological loss of water through transpiration; (c) infiltration increased through improved soil structure at the boundaries; and (d) throughflow effected by modified hydraulic gradients. An extensive monitoring programme of a 20m transect through a hedgerow in the Skell Catchment, Northern England occurred from April 2014 to October 2015. The holistic hydrological cycle was monitored, including precipitation and soil moisture at different distances from the hedgerow, leaf wetness interception, stemflow collars, and throughfall gauges, and transpiration losses from the hedgerow. Results indicate that hedgerows modify precipitation volumes at different distances along the transect, but that relationships are complex, probably related to event specific weather conditions such as wind direction and speed and rainfall intensity. Soil moisture levels are significantly (p<0.001) lower along the hedgerow compared to 1, 3 and 10m away from it in all seasons. It has also been shown that hedgerows modify hydrological connectivity at the catchment scale.

Broad-Scale Patterns of Late Jurassic Dinosaur Paleoecology

PubMed Central

Noto, Christopher R.; Grossman, Ari

2010-01-01

Background There have been numerous studies on dinosaur biogeographic distribution patterns. However, these distribution data have not yet been applied to ecological questions. Ecological studies of dinosaurs have tended to focus on reconstructing individual taxa, usually through comparisons to modern analogs. Fewer studies have sought to determine if the ecological structure of fossil assemblages is preserved and, if so, how dinosaur communities varied. Climate is a major component driving differences between communities. If the ecological structure of a fossil locality is preserved, we expect that dinosaur assemblages from similar environments will share a similar ecological structure. Methodology/Principal Findings This study applies Ecological Structure Analysis (ESA) to a dataset of 100+ dinosaur taxa arranged into twelve composite fossil assemblages from around the world. Each assemblage was assigned a climate zone (biome) based on its location. Dinosaur taxa were placed into ecomorphological categories. The proportion of each category creates an ecological profile for the assemblage, which were compared using cluster and principal components analyses. Assemblages grouped according to biome, with most coming from arid or semi-arid/seasonal climates. Differences between assemblages are tied to the proportion of large high-browsing vs. small ground-foraging herbivores, which separates arid from semi-arid and moister environments, respectively. However, the effects of historical, taphonomic, and other environmental factors are still evident. Conclusions/Significance This study is the first to show that the general ecological structure of Late Jurassic dinosaur assemblages is preserved at large scales and can be assessed quantitatively. Despite a broad similarity of climatic conditions, a degree of ecological variation is observed between assemblages, from arid to moist. Taxonomic differences between Asia and the other regions demonstrate at least one case of ecosystem convergence. The proportion of different ecomorphs, which reflects the prevailing climatic and environmental conditions present during fossil deposition, may therefore be used to differentiate Late Jurassic dinosaur fossil assemblages. This method is broadly applicable to different taxa and times, allowing one to address questions of evolutionary, biogeographic, and climatic importance. PMID:20838442

Broad-scale patterns of late jurassic dinosaur paleoecology.

PubMed

Noto, Christopher R; Grossman, Ari

2010-09-03

There have been numerous studies on dinosaur biogeographic distribution patterns. However, these distribution data have not yet been applied to ecological questions. Ecological studies of dinosaurs have tended to focus on reconstructing individual taxa, usually through comparisons to modern analogs. Fewer studies have sought to determine if the ecological structure of fossil assemblages is preserved and, if so, how dinosaur communities varied. Climate is a major component driving differences between communities. If the ecological structure of a fossil locality is preserved, we expect that dinosaur assemblages from similar environments will share a similar ecological structure. This study applies Ecological Structure Analysis (ESA) to a dataset of 100+ dinosaur taxa arranged into twelve composite fossil assemblages from around the world. Each assemblage was assigned a climate zone (biome) based on its location. Dinosaur taxa were placed into ecomorphological categories. The proportion of each category creates an ecological profile for the assemblage, which were compared using cluster and principal components analyses. Assemblages grouped according to biome, with most coming from arid or semi-arid/seasonal climates. Differences between assemblages are tied to the proportion of large high-browsing vs. small ground-foraging herbivores, which separates arid from semi-arid and moister environments, respectively. However, the effects of historical, taphonomic, and other environmental factors are still evident. This study is the first to show that the general ecological structure of Late Jurassic dinosaur assemblages is preserved at large scales and can be assessed quantitatively. Despite a broad similarity of climatic conditions, a degree of ecological variation is observed between assemblages, from arid to moist. Taxonomic differences between Asia and the other regions demonstrate at least one case of ecosystem convergence. The proportion of different ecomorphs, which reflects the prevailing climatic and environmental conditions present during fossil deposition, may therefore be used to differentiate Late Jurassic dinosaur fossil assemblages. This method is broadly applicable to different taxa and times, allowing one to address questions of evolutionary, biogeographic, and climatic importance.

Cyanobactins from Cyanobacteria: Current Genetic and Chemical State of Knowledge.

PubMed

Martins, Joana; Vasconcelos, Vitor

2015-11-13

Cyanobacteria are considered to be one of the most promising sources of new, natural products. Apart from non-ribosomal peptides and polyketides, ribosomally synthesized and post-translationally modified peptides (RiPPs) are one of the leading groups of bioactive compounds produced by cyanobacteria. Among these, cyanobactins have sparked attention due to their interesting bioactivities and for their potential to be prospective candidates in the development of drugs. It is assumed that the primary source of cyanobactins is cyanobacteria, although these compounds have also been isolated from marine animals such as ascidians, sponges and mollusks. The aim of this review is to update the current knowledge of cyanobactins, recognized as being produced by cyanobacteria, and to emphasize their genetic clusters and chemical structures as well as their bioactivities, ecological roles and biotechnological potential.

Values: the dynamic nexus between biology, ecology and culture.

PubMed

Fischer, Ronald; Boer, Diana

2016-04-01

Values are motivational goals that influence attitudes, behaviors and evaluations. Cross-cultural evidence suggests that values show a systematic structure. Personal and cultural variations in the value structure, value priorities and value links to attitudes, behavior and well-being reflect contextual constraints and affordances in the environment, suggesting that values function as broadly adaptive psychological structures. The internal structure of values (the descriptive value system) becomes more clearly differentiated in more economically developed contexts. Value priorities shift toward more autonomous, self-expressive and individualistic orientations with greater economic resources and less ecological stress. In addition to systematic changes in internal structure, value links to attitudes, behaviors and well-being are influenced by economic, ecological and institutional contexts. Values are more likely to be expressed in attitudes and behavior if individuals have greater access to economic resources, experience less institutional and ecological stress or when the values reinforce culturally normative behavior. Frontiers for further value research include a greater examination of the neural underpinnings of values in specific ecological contexts and across the lifespan; and an examination of how values are behaviorally instantiated in different environments. Copyright © 2015 Elsevier Ltd. All rights reserved.

Level, source identification, and risk analysis of heavy metal in surface sediments from river-lake ecosystems in the Poyang Lake, China.

PubMed

Zhang, Hua; Jiang, Yinghui; Ding, Mingjun; Xie, Zhenglei

2017-09-01

The concentrations, sources, and risks of heavy metals (Fe, Al, Mn, Cr, Co, Ni, Cu, Zn, As, Cd, W, Pb, and Tl) in sediments in five river-lake ecosystems in the Poyang Lake region were studied. The concentrations of the heavy metals varied spatially, with most of the highest concentrations in the Raohe river-lake ecosystem (RH). All heavy metals except As, Cd, W, and Tl were enriched in sediments possessing high total organic carbon contents or in finer sediments. Based on enrichment factors and statistical methods, it was found that Cd in sediments in the Xiushui (XS), Ganjiang (GJ), Xinjiang (XJ) river-lake ecosystems, and RH; Mn in the XS, GJ, and RH; and W in the XS and GJ were greatly affected by anthropogenic inputs. Moreover, the origins of Cu, Zn, and As require more attention due to the high concentrations found. The high enrichment factor of Cd in the sediments indicated that this metal might cause significant pollution in the environment. The results of the modified potential ecological risk index revealed that the XS, GJ, RH, and XJ were at considerable ecological risk, while the sediments in the Fuhe river-lake ecosystem (FH) were at moderate ecological risk, with Cd contributing the highest proportion of risk. The hazard score fundamentally validated the modified potential ecological risk analysis and revealed a mean toxicity of 57.80% to the benthic organisms in the RH.

Landscape moderation of biodiversity patterns and processes - eight hypotheses.

PubMed

Tscharntke, Teja; Tylianakis, Jason M; Rand, Tatyana A; Didham, Raphael K; Fahrig, Lenore; Batáry, Péter; Bengtsson, Janne; Clough, Yann; Crist, Thomas O; Dormann, Carsten F; Ewers, Robert M; Fründ, Jochen; Holt, Robert D; Holzschuh, Andrea; Klein, Alexandra M; Kleijn, David; Kremen, Claire; Landis, Doug A; Laurance, William; Lindenmayer, David; Scherber, Christoph; Sodhi, Navjot; Steffan-Dewenter, Ingolf; Thies, Carsten; van der Putten, Wim H; Westphal, Catrin

2012-08-01

Understanding how landscape characteristics affect biodiversity patterns and ecological processes at local and landscape scales is critical for mitigating effects of global environmental change. In this review, we use knowledge gained from human-modified landscapes to suggest eight hypotheses, which we hope will encourage more systematic research on the role of landscape composition and configuration in determining the structure of ecological communities, ecosystem functioning and services. We organize the eight hypotheses under four overarching themes. Section A: 'landscape moderation of biodiversity patterns' includes (1) the landscape species pool hypothesis-the size of the landscape-wide species pool moderates local (alpha) biodiversity, and (2) the dominance of beta diversity hypothesis-landscape-moderated dissimilarity of local communities determines landscape-wide biodiversity and overrides negative local effects of habitat fragmentation on biodiversity. Section B: 'landscape moderation of population dynamics' includes (3) the cross-habitat spillover hypothesis-landscape-moderated spillover of energy, resources and organisms across habitats, including between managed and natural ecosystems, influences landscape-wide community structure and associated processes and (4) the landscape-moderated concentration and dilution hypothesis-spatial and temporal changes in landscape composition can cause transient concentration or dilution of populations with functional consequences. Section C: 'landscape moderation of functional trait selection' includes (5) the landscape-moderated functional trait selection hypothesis-landscape moderation of species trait selection shapes the functional role and trajectory of community assembly, and (6) the landscape-moderated insurance hypothesis-landscape complexity provides spatial and temporal insurance, i.e. high resilience and stability of ecological processes in changing environments. Section D: 'landscape constraints on conservation management' includes (7) the intermediate landscape-complexity hypothesis-landscape-moderated effectiveness of local conservation management is highest in structurally simple, rather than in cleared (i.e. extremely simplified) or in complex landscapes, and (8) the landscape-moderated biodiversity versus ecosystem service management hypothesis-landscape-moderated biodiversity conservation to optimize functional diversity and related ecosystem services will not protect endangered species. Shifting our research focus from local to landscape-moderated effects on biodiversity will be critical to developing solutions for future biodiversity and ecosystem service management. © 2012 The Authors. Biological Reviews © 2012 Cambridge Philosophical Society.

Information and the Ecology of Scholars

ERIC Educational Resources Information Center

Blackburn, Thomas R.

1973-01-01

Suggests a logical basis for the use of ecological concepts in modeling a special subculture; that of scholars (and in particular scientists), who produce, barter, and structure information as an ecosystem produces, exchanges, and structures biomass. (JR)

Decoupling of body-plan diversification and ecological structuring during the Ediacaran–Cambrian transition: evolutionary and geobiological feedbacks

PubMed Central

Mángano, M. Gabriela; Buatois, Luis A.

2014-01-01

The rapid appearance of bilaterian clades at the beginning of the Phanerozoic is one of the most intriguing topics in macroevolution. However, the complex feedbacks between diversification and ecological interactions are still poorly understood. Here, we show that a systematic and comprehensive analysis of the trace-fossil record of the Ediacaran–Cambrian transition indicates that body-plan diversification and ecological structuring were decoupled. The appearance of a wide repertoire of behavioural strategies and body plans occurred by the Fortunian. However, a major shift in benthic ecological structure, recording the establishment of a suspension-feeder infauna, increased complexity of the trophic web, and coupling of benthos and plankton took place during Cambrian Stage 2. Both phases were accompanied by different styles of ecosystem engineering, but only the second one resulted in the establishment of the Phanerozoic-style ecology. In turn, the suspension-feeding infauna may have been the ecological drivers of a further diversification of deposit-feeding strategies by Cambrian Stage 3, favouring an ecological spillover scenario. Trace-fossil information strongly supports the Cambrian explosion, but allows for a short time of phylogenetic fuse during the terminal Ediacaran–Fortunian. PMID:24523279

Decoupling of body-plan diversification and ecological structuring during the Ediacaran-Cambrian transition: evolutionary and geobiological feedbacks.

PubMed

Mángano, M Gabriela; Buatois, Luis A

2014-04-07

The rapid appearance of bilaterian clades at the beginning of the Phanerozoic is one of the most intriguing topics in macroevolution. However, the complex feedbacks between diversification and ecological interactions are still poorly understood. Here, we show that a systematic and comprehensive analysis of the trace-fossil record of the Ediacaran-Cambrian transition indicates that body-plan diversification and ecological structuring were decoupled. The appearance of a wide repertoire of behavioural strategies and body plans occurred by the Fortunian. However, a major shift in benthic ecological structure, recording the establishment of a suspension-feeder infauna, increased complexity of the trophic web, and coupling of benthos and plankton took place during Cambrian Stage 2. Both phases were accompanied by different styles of ecosystem engineering, but only the second one resulted in the establishment of the Phanerozoic-style ecology. In turn, the suspension-feeding infauna may have been the ecological drivers of a further diversification of deposit-feeding strategies by Cambrian Stage 3, favouring an ecological spillover scenario. Trace-fossil information strongly supports the Cambrian explosion, but allows for a short time of phylogenetic fuse during the terminal Ediacaran-Fortunian.

A socio-ecological adaptive approach to contaminated mega-site management: from 'control and correct' to 'coping with change'.

PubMed

Schirmer, Mario; Lyon, Ken; Armstrong, James E; Farrell, Katharine N

2012-01-01

Mega-sites have a notable impact on surrounding ecological systems. At such sites there are substantial risks associated with complex socio-ecological interactions that are hard to characterize, let alone model and predict. While the urge to control and clean-up mega-sites (control and correct) is understandable, rather than setting a goal of cleaning up such sites, we suggest a more realistic response strategy is to address these massive and persistent sources of contamination by acknowledging their position as new features of the socio-ecological landscapes within which they are located. As it seems nearly impossible to clean up such sites, we argue for consideration of a 'coping with change' rather than a 'control and correct' approach. This strategy recognizes that the current management option for a mega-site, in light of its physical complexities and due to changing societal preferences, geochemical transformations, hydrogeology knowledge and remedial technology options may not remain optimal in future, and therefore needs to be continuously adapted, as community, ecology, technology and understanding change over time. This approach creates an opportunity to consider the relationship between a mega-site and its human and ecological environments in a different and more dynamic way. Our proposed approach relies on iterative adaptive management to incorporate mega-site management into the overall socio-ecological systems of the site's context. This approach effectively embeds mega-site management planning in a triple bottom line and environmental sustainability structure, rather than simply using single measures of success, such as contaminant-based guidelines. Recognizing that there is probably no best solution for managing a mega-site, we present a starting point for engaging constructively with this seemingly intractable issue. Therefore, we aim to initiate discussion about a new approach to mega-site management, in which the complexity of the problems posed by mega-sites is reflected upon in its entirety. These complexities are associated with uncertainties and unknowns that have to be addressed, as they have an impact on the strategies being developed and applied. We contend that the best that can be hoped for in mega-site management is an acceptable solution for the current state of affairs, with good flexibility to modify strategies as new site conditions, remediation possibilities, community preferences and management objectives develop over time. Copyright © 2011 Elsevier B.V. All rights reserved.

How Neighborhoods Influence Health: Lessons to be learned from the application of political ecology

PubMed Central

Chitewere, Tendai; Shim, Janet K.; Barker, Judith C.; Yen, Irene H.

2017-01-01

AIM This paper articulates how political ecology can be a useful tool for asking fundamental questions and applying relevant methods to investigate structures that impact relationship between neighborhood and health. Through a narrative analysis, we identify how political ecology can develop our future agendas for neighborhood-health research as it relates to social, political, environmental, and economic structures. Political ecology makes clear the connection between political economy and neighborhood by highlighting the historical and structural processes that produce and maintain social inequality, which affect health and well-being. These concepts encourage researchers to examine how people construct neighborhood and health in different ways that, in turn, can influence different health outcomes and, thus, efforts to address solutions. PMID:28342425

How Neighborhoods Influence Health: Lessons to be learned from the application of political ecology.

PubMed

Chitewere, Tendai; Shim, Janet K; Barker, Judith C; Yen, Irene H

2017-05-01

This paper articulates how political ecology can be a useful tool for asking fundamental questions and applying relevant methods to investigate structures that impact relationship between neighborhood and health. Through a narrative analysis, we identify how political ecology can develop our future agendas for neighborhood-health research as it relates to social, political, environmental, and economic structures. Political ecology makes clear the connection between political economy and neighborhood by highlighting the historical and structural processes that produce and maintain social inequality, which affect health and well-being. These concepts encourage researchers to examine how people construct neighborhood and health in different ways that, in turn, can influence different health outcomes and, thus, efforts to address solutions. Published by Elsevier Ltd.

The importance of biodiversity and dominance for multiple ecosystem functions in a human-modified tropical landscape.

PubMed

Lohbeck, Madelon; Bongers, Frans; Martinez-Ramos, Miguel; Poorter, Lourens

2016-10-01

Many studies suggest that biodiversity may be particularly important for ecosystem multifunctionality, because different species with different traits can contribute to different functions. Support, however, comes mostly from experimental studies conducted at small spatial scales in low-diversity systems. Here, we test whether different species contribute to different ecosystem functions that are important for carbon cycling in a high-diversity human-modified tropical forest landscape in Southern Mexico. We quantified aboveground standing biomass, primary productivity, litter production, and wood decomposition at the landscape level, and evaluated the extent to which tree species contribute to these ecosystem functions. We used simulations to tease apart the effects of species richness, species dominance and species functional traits on ecosystem functions. We found that dominance was more important than species traits in determining a species' contribution to ecosystem functions. As a consequence of the high dominance in human-modified landscapes, the same small subset of species mattered across different functions. In human-modified landscapes in the tropics, biodiversity may play a limited role for ecosystem multifunctionality due to the potentially large effect of species dominance on biogeochemical functions. However, given the spatial and temporal turnover in species dominance, biodiversity may be critically important for the maintenance and resilience of ecosystem functions. © 2016 The Authors. Ecology, published by Wiley Periodicals, Inc., on behalf of the Ecological Society of America.

75 FR 35829 - Bear Lake National Wildlife Refuge, Oxford Slough Waterfowl Production Area, ID

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-23

... substantially modified the natural hydrology of the former Dingle Swamp by diverting the Bear River to flow into... hydrology and ecological processes of the Bear Lake Watershed. Oxford Slough Waterfowl Production Area...

Silvicultural treatments

Treesearch

Carl E. Fiedler

2000-01-01

Sustainable, ecologically-based management of pine/ fir forests requires silviculturists to integrate several treatments that emulate historic disturbance processes. Restoration prescriptions typically include cleaning or heavy understory thinning, improvement cutting to reduce the proportion of firs, and modified selection cutting to reduce overall stand density,...

ESTABLISHMENT OF TRANSGENIC CREEPING BENTGRASS (AGROSTIS STOLONIFERA L.) IN NON-AGRONOMIC HABITATS

EPA Science Inventory

Concerns about genetically modified crops include transgene flow to compatible wild species and potential unintended ecological consequences associated with transgene introgression. To date, there has been little empirical documentation of the relative frequency of establishment...

Derivation and interpretation of hazard quotients to assess ecological risks from the cultivation of insect-resistant transgenic crops.

PubMed

Raybould, Alan; Caron-Lormier, Geoffrey; Bohan, David A

2011-06-08

Cost-effective and rigorous risk assessments for chemicals may be based on hazard quotients (HQs): the ratio of a measure of exposure to a substance and a measure of the effect of that substance. HQs have been used for many years in ecological risk assessments for the use of synthetic pesticides in agriculture, and methods for calculating pesticide HQs have been adapted for use with transgenic crops. This paper describes how laboratory methods for assessing the ecotoxicological effects of synthetic pesticides have been modified for the measurement of effects of insecticidal proteins, and how these effect measures are combined with exposure estimates to derive HQs for assessing the ecological risks from the cultivation of insect-resistant transgenic crops. The potential for ecological modeling to inform the design of laboratory effects tests for insecticidal proteins is also discussed.

Evolutionary Connectionism: Algorithmic Principles Underlying the Evolution of Biological Organisation in Evo-Devo, Evo-Eco and Evolutionary Transitions.

PubMed

Watson, Richard A; Mills, Rob; Buckley, C L; Kouvaris, Kostas; Jackson, Adam; Powers, Simon T; Cox, Chris; Tudge, Simon; Davies, Adam; Kounios, Loizos; Power, Daniel

2016-01-01

The mechanisms of variation, selection and inheritance, on which evolution by natural selection depends, are not fixed over evolutionary time. Current evolutionary biology is increasingly focussed on understanding how the evolution of developmental organisations modifies the distribution of phenotypic variation, the evolution of ecological relationships modifies the selective environment, and the evolution of reproductive relationships modifies the heritability of the evolutionary unit. The major transitions in evolution, in particular, involve radical changes in developmental, ecological and reproductive organisations that instantiate variation, selection and inheritance at a higher level of biological organisation. However, current evolutionary theory is poorly equipped to describe how these organisations change over evolutionary time and especially how that results in adaptive complexes at successive scales of organisation (the key problem is that evolution is self-referential, i.e. the products of evolution change the parameters of the evolutionary process). Here we first reinterpret the central open questions in these domains from a perspective that emphasises the common underlying themes. We then synthesise the findings from a developing body of work that is building a new theoretical approach to these questions by converting well-understood theory and results from models of cognitive learning. Specifically, connectionist models of memory and learning demonstrate how simple incremental mechanisms, adjusting the relationships between individually-simple components, can produce organisations that exhibit complex system-level behaviours and improve the adaptive capabilities of the system. We use the term "evolutionary connectionism" to recognise that, by functionally equivalent processes, natural selection acting on the relationships within and between evolutionary entities can result in organisations that produce complex system-level behaviours in evolutionary systems and modify the adaptive capabilities of natural selection over time. We review the evidence supporting the functional equivalences between the domains of learning and of evolution, and discuss the potential for this to resolve conceptual problems in our understanding of the evolution of developmental, ecological and reproductive organisations and, in particular, the major evolutionary transitions.

[Applications of habitat equivalency analysis in ecological damage assessment of oil spill incident].

PubMed

Yang, Yin; Han, Da-xiong; Wang, Hai-yan

2011-08-01

Habitat equivalency analysis (HEA) is one of the methods commonly used by U.S. National Oceanic and Atmospheric Administration in natural resources damage assessment, but rarely applied in China. Based on the theory of HEA and the assessment practices of domestic oil spill incidents, a modification on the HEA was made in this paper, and applied to calculate the habitat value in oil spill incidents. According to the data collected from an oil spill incident in China, the modified HEA was applied in a case study to scale the compensatory-restoration. By introducing the ecological service equivalent factor to transfer various habitats, it was achieved to value of the injured habitats in ecological damage assessment of oil spill incident.

The use of typed lambda calculus for comprehension and construction of simulation models in the domain of ecology

NASA Technical Reports Server (NTRS)

Uschold, Michael

1992-01-01

We are concerned with two important issues in simulation modelling: model comprehension and model construction. Model comprehension is limited because many important choices taken during the modelling process are not documented. This makes it difficult for models to be modified or used by others. A key factor hindering model construction is the vast modelling search space which must be navigated. This is exacerbated by the fact that many modellers are unfamiliar with the terms and concepts catered to by current tools. The root of both problems is the lack of facilities for representing or reasoning about domain concepts in current simulation technology. The basis for our achievements in both of these areas is the development of a language with two distinct levels; one for representing domain information, and the other for representing the simulation model. Of equal importance, is the fact that we make formal connections between these two levels. The domain we are concerned with is ecological modelling. This language, called Elklogic, is based on the typed lambda calculus. Important features include a rich type structure, the use of various higher order functions, and semantics. This enables complex expressions to be constructed from relatively few primitives. The meaning of each expression can be determined in terms of the domain, the simulation model, or the relationship between the two. We describe a novel representation for sets and substructure, and a variety of other general concepts that are especially useful in the ecological domain. We use the type structure in a novel way: for controlling the modelling search space, rather than a proof search space. We facilitate model comprehension by representing modelling decisions that are embodied in the simulation model. We represent the simulation model separately from, but in terms of a domain mode. The explicit links between the two models constitute the modelling decisions. The semantics of Elklogic enables English text to be generated to explain the simulation model in domain terms.

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.

Accommodating environmental variation in population models: metaphysiological biomass loss accounting.

PubMed

Owen-Smith, Norman

2011-07-01

1. There is a pressing need for population models that can reliably predict responses to changing environmental conditions and diagnose the causes of variation in abundance in space as well as through time. In this 'how to' article, it is outlined how standard population models can be modified to accommodate environmental variation in a heuristically conducive way. This approach is based on metaphysiological modelling concepts linking populations within food web contexts and underlying behaviour governing resource selection. Using population biomass as the currency, population changes can be considered at fine temporal scales taking into account seasonal variation. Density feedbacks are generated through the seasonal depression of resources even in the absence of interference competition. 2. Examples described include (i) metaphysiological modifications of Lotka-Volterra equations for coupled consumer-resource dynamics, accommodating seasonal variation in resource quality as well as availability, resource-dependent mortality and additive predation, (ii) spatial variation in habitat suitability evident from the population abundance attained, taking into account resource heterogeneity and consumer choice using empirical data, (iii) accommodating population structure through the variable sensitivity of life-history stages to resource deficiencies, affecting susceptibility to oscillatory dynamics and (iv) expansion of density-dependent equations to accommodate various biomass losses reducing population growth rate below its potential, including reductions in reproductive outputs. Supporting computational code and parameter values are provided. 3. The essential features of metaphysiological population models include (i) the biomass currency enabling within-year dynamics to be represented appropriately, (ii) distinguishing various processes reducing population growth below its potential, (iii) structural consistency in the representation of interacting populations and (iv) capacity to accommodate environmental variation in space as well as through time. Biomass dynamics provide a common currency linking behavioural, population and food web ecology. 4. Metaphysiological biomass loss accounting provides a conceptual framework more conducive for projecting and interpreting the population consequences of climatic shifts and human transformations of habitats than standard modelling approaches. © 2011 The Author. Journal of Animal Ecology © 2011 British Ecological Society.

NEON: the first continental-scale ecological observatory with airborne remote sensing of vegetation canopy biochemistry and structure

Treesearch

Thomas U. Kampe; Brian R. Johnson; Michele Kuester; Michael Keller

2010-01-01

The National Ecological Observatory Network (NEON) is an ecological observation platform for discovering, understanding and forecasting the impacts of climate change, land use change, and invasive species on continental-scale ecology. NEON will operate for 30 years and gather long-term data on ecological response changes and on feedbacks with the geosphere, hydrosphere...

Ecological Understanding 2: Transformation--A Key to Ecological Understanding.

ERIC Educational Resources Information Center

Carlsson, Britta

2002-01-01

Describes the structure and general features of the phenomenon of ecological understanding. Presents qualitatively different ways of experiencing cycling of matter and the flow of energy in the context of ecosystems. The idea of transformation is key to the development of ecological understanding. (Contains 17 references.) (Author/YDS)

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.

Watershed-scale effects of isolated wetlands on downstream hydrology: modeling approaches

EPA Science Inventory

Geographically isolated wetlands (GIWs) are depressional features on an eroding landscape that are entirely surrounded by uplands. These wetlands are purported to provide an array of ecological and watershed values and functions, including increasing biodiversity, modifying water...

RESPONSE OF PLANT COMMUNITIES TO MULTIPLE STRESSES

EPA Science Inventory

Single species tests lack the ecological realism necessary to predict the effects of toxicants in natural environments. Field tests are expensive and the results can be difficult to interpret. To address these conflicting problems, open top chambers were modified to contain pla...

ESTABLISHMENT OF TRANSGENETIC HERBICIDE-RESISTANT CREEPING BENTGRASS (AGROSTIS STOLONIFERA L.) IN NONAGRONOMIC HABITATS

EPA Science Inventory

Concerns about genetically modified (GM) crops include transgene flow to compatible wild species and unintended ecological consequences of potential transgene introgression. However, there has been little empirical documentation of establishment and distribution of transgenic pla...

Towards the use of Structural Loop Analysis to Study System Behaviour of Socio-Ecological Systems.

NASA Astrophysics Data System (ADS)

Abram, Joseph; Dyke, James

2016-04-01

Maintaining socio-ecological systems in desirable states is key to developing a growing economy, alleviating poverty and achieving a sustainable future. While the driving forces of an environmental system are often well known, the dynamics impacting these drivers can be hidden within a tangled structure of causal chains and feedback loops. A lack of understanding of a system's dynamic structure and its influence on a system's behaviour can cause unforeseen side-effects during model scenario testing and policy implementation. Structural Loop analysis of socio-ecological system models identifies dominant feedback structures during times of behavioural shift, allowing the user to monitor key influential drivers during model simulation. This work carries out Loop Eigenvalue Elasticity Analysis (LEEA) on three system dynamic models, exploring tipping points in lake systems undergoing eutrophication. The purpose is to explore the potential benefits and limitations of the technique in the field of socio-ecology. The LEEA technique shows promise for socio-ecological systems which undergo regime shifts or express oscillatory trends, but shows limited usefulness with large models. The results of this work highlight changes in feedback loop dominance, years prior to eutrophic tipping events in lake systems. LEEA could be used as an early warning signal to impending system changes, complementary to other known early warning signals. This approach could improve our understanding during critical times of a system's behaviour, changing how we approach model analysis and the way scenario testing and policy implementation are addressed in socio-ecological system models.

Global Patterns in Ecological Indicators of Marine Food Webs: A Modelling Approach

PubMed Central

Heymans, Johanna Jacomina; Coll, Marta; Libralato, Simone; Morissette, Lyne; Christensen, Villy

2014-01-01

Background Ecological attributes estimated from food web models have the potential to be indicators of good environmental status given their capabilities to describe redundancy, food web changes, and sensitivity to fishing. They can be used as a baseline to show how they might be modified in the future with human impacts such as climate change, acidification, eutrophication, or overfishing. Methodology In this study ecological network analysis indicators of 105 marine food web models were tested for variation with traits such as ecosystem type, latitude, ocean basin, depth, size, time period, and exploitation state, whilst also considering structural properties of the models such as number of linkages, number of living functional groups or total number of functional groups as covariate factors. Principal findings Eight indicators were robust to model construction: relative ascendency; relative overhead; redundancy; total systems throughput (TST); primary production/TST; consumption/TST; export/TST; and total biomass of the community. Large-scale differences were seen in the ecosystems of the Atlantic and Pacific Oceans, with the Western Atlantic being more complex with an increased ability to mitigate impacts, while the Eastern Atlantic showed lower internal complexity. In addition, the Eastern Pacific was less organised than the Eastern Atlantic although both of these systems had increased primary production as eastern boundary current systems. Differences by ecosystem type highlighted coral reefs as having the largest energy flow and total biomass per unit of surface, while lagoons, estuaries, and bays had lower transfer efficiencies and higher recycling. These differences prevailed over time, although some traits changed with fishing intensity. Keystone groups were mainly higher trophic level species with mostly top-down effects, while structural/dominant groups were mainly lower trophic level groups (benthic primary producers such as seagrass and macroalgae, and invertebrates). Keystone groups were prevalent in estuarine or small/shallow systems, and in systems with reduced fishing pressure. Changes to the abundance of key functional groups might have significant implications for the functioning of ecosystems and should be avoided through management. Conclusion/significance Our results provide additional understanding of patterns of structural and functional indicators in different ecosystems. Ecosystem traits such as type, size, depth, and location need to be accounted for when setting reference levels as these affect absolute values of ecological indicators. Therefore, establishing absolute reference values for ecosystem indicators may not be suitable to the ecosystem-based, precautionary approach. Reference levels for ecosystem indicators should be developed for individual ecosystems or ecosystems with the same typologies (similar location, ecosystem type, etc.) and not benchmarked against all other ecosystems. PMID:24763610

Global patterns in ecological indicators of marine food webs: a modelling approach.

PubMed

Heymans, Johanna Jacomina; Coll, Marta; Libralato, Simone; Morissette, Lyne; Christensen, Villy

2014-01-01

Ecological attributes estimated from food web models have the potential to be indicators of good environmental status given their capabilities to describe redundancy, food web changes, and sensitivity to fishing. They can be used as a baseline to show how they might be modified in the future with human impacts such as climate change, acidification, eutrophication, or overfishing. In this study ecological network analysis indicators of 105 marine food web models were tested for variation with traits such as ecosystem type, latitude, ocean basin, depth, size, time period, and exploitation state, whilst also considering structural properties of the models such as number of linkages, number of living functional groups or total number of functional groups as covariate factors. Eight indicators were robust to model construction: relative ascendency; relative overhead; redundancy; total systems throughput (TST); primary production/TST; consumption/TST; export/TST; and total biomass of the community. Large-scale differences were seen in the ecosystems of the Atlantic and Pacific Oceans, with the Western Atlantic being more complex with an increased ability to mitigate impacts, while the Eastern Atlantic showed lower internal complexity. In addition, the Eastern Pacific was less organised than the Eastern Atlantic although both of these systems had increased primary production as eastern boundary current systems. Differences by ecosystem type highlighted coral reefs as having the largest energy flow and total biomass per unit of surface, while lagoons, estuaries, and bays had lower transfer efficiencies and higher recycling. These differences prevailed over time, although some traits changed with fishing intensity. Keystone groups were mainly higher trophic level species with mostly top-down effects, while structural/dominant groups were mainly lower trophic level groups (benthic primary producers such as seagrass and macroalgae, and invertebrates). Keystone groups were prevalent in estuarine or small/shallow systems, and in systems with reduced fishing pressure. Changes to the abundance of key functional groups might have significant implications for the functioning of ecosystems and should be avoided through management. Our results provide additional understanding of patterns of structural and functional indicators in different ecosystems. Ecosystem traits such as type, size, depth, and location need to be accounted for when setting reference levels as these affect absolute values of ecological indicators. Therefore, establishing absolute reference values for ecosystem indicators may not be suitable to the ecosystem-based, precautionary approach. Reference levels for ecosystem indicators should be developed for individual ecosystems or ecosystems with the same typologies (similar location, ecosystem type, etc.) and not benchmarked against all other ecosystems.

Framework for Ecological Risk Assessment

EPA Pesticide Factsheets

This is the first step in a long-term effort to develop risk assessment guidelines for ecological effects. Its primary purpose is to offer a simple, flexible structure for conducting and evaluating ecological risk assessment within EPA.

Trophic interaction modifications: an empirical and theoretical framework.

PubMed

Terry, J Christopher D; Morris, Rebecca J; Bonsall, Michael B

2017-10-01

Consumer-resource interactions are often influenced by other species in the community. At present these 'trophic interaction modifications' are rarely included in ecological models despite demonstrations that they can drive system dynamics. Here, we advocate and extend an approach that has the potential to unite and represent this key group of non-trophic interactions by emphasising the change to trophic interactions induced by modifying species. We highlight the opportunities this approach brings in comparison to frameworks that coerce trophic interaction modifications into pairwise relationships. To establish common frames of reference and explore the value of the approach, we set out a range of metrics for the 'strength' of an interaction modification which incorporate increasing levels of contextual information about the system. Through demonstrations in three-species model systems, we establish that these metrics capture complimentary aspects of interaction modifications. We show how the approach can be used in a range of empirical contexts; we identify as specific gaps in current understanding experiments with multiple levels of modifier species and the distributions of modifications in networks. The trophic interaction modification approach we propose can motivate and unite empirical and theoretical studies of system dynamics, providing a route to confront ecological complexity. © 2017 The Authors. Ecology Letters published by CNRS and John Wiley & Sons Ltd.

Ecological connectivity networks in rapidly expanding cities.

PubMed

Nor, Amal Najihah M; Corstanje, Ron; Harris, Jim A; Grafius, Darren R; Siriwardena, Gavin M

2017-06-01

Urban expansion increases fragmentation of the landscape. In effect, fragmentation decreases connectivity, causes green space loss and impacts upon the ecology and function of green space. Restoration of the functionality of green space often requires restoring the ecological connectivity of this green space within the city matrix. However, identifying ecological corridors that integrate different structural and functional connectivity of green space remains vague. Assessing connectivity for developing an ecological network by using efficient models is essential to improve these networks under rapid urban expansion. This paper presents a novel methodological approach to assess and model connectivity for the Eurasian tree sparrow ( Passer montanus ) and Yellow-vented bulbul ( Pycnonotus goiavier ) in three cities (Kuala Lumpur, Malaysia; Jakarta, Indonesia and Metro Manila, Philippines). The approach identifies potential priority corridors for ecological connectivity networks. The study combined circuit models, connectivity analysis and least-cost models to identify potential corridors by integrating structure and function of green space patches to provide reliable ecological connectivity network models in the cities. Relevant parameters such as landscape resistance and green space structure (vegetation density, patch size and patch distance) were derived from an expert and literature-based approach based on the preference of bird behaviour. The integrated models allowed the assessment of connectivity for both species using different measures of green space structure revealing the potential corridors and least-cost pathways for both bird species at the patch sites. The implementation of improvements to the identified corridors could increase the connectivity of green space. This study provides examples of how combining models can contribute to the improvement of ecological networks in rapidly expanding cities and demonstrates the usefulness of such models for biodiversity conservation and urban planning.

Multiple regimes of robust patterns between network structure and biodiversity

NASA Astrophysics Data System (ADS)

Jover, Luis F.; Flores, Cesar O.; Cortez, Michael H.; Weitz, Joshua S.

2015-12-01

Ecological networks such as plant-pollinator and host-parasite networks have structured interactions that define who interacts with whom. The structure of interactions also shapes ecological and evolutionary dynamics. Yet, there is significant ongoing debate as to whether certain structures, e.g., nestedness, contribute positively, negatively or not at all to biodiversity. We contend that examining variation in life history traits is key to disentangling the potential relationship between network structure and biodiversity. Here, we do so by analyzing a dynamic model of virus-bacteria interactions across a spectrum of network structures. Consistent with prior studies, we find plausible parameter domains exhibiting strong, positive relationships between nestedness and biodiversity. Yet, the same model can exhibit negative relationships between nestedness and biodiversity when examined in a distinct, plausible region of parameter space. We discuss steps towards identifying when network structure could, on its own, drive the resilience, sustainability, and even conservation of ecological communities.

Multiple regimes of robust patterns between network structure and biodiversity

PubMed Central

Jover, Luis F.; Flores, Cesar O.; Cortez, Michael H.; Weitz, Joshua S.

2015-01-01

Ecological networks such as plant-pollinator and host-parasite networks have structured interactions that define who interacts with whom. The structure of interactions also shapes ecological and evolutionary dynamics. Yet, there is significant ongoing debate as to whether certain structures, e.g., nestedness, contribute positively, negatively or not at all to biodiversity. We contend that examining variation in life history traits is key to disentangling the potential relationship between network structure and biodiversity. Here, we do so by analyzing a dynamic model of virus-bacteria interactions across a spectrum of network structures. Consistent with prior studies, we find plausible parameter domains exhibiting strong, positive relationships between nestedness and biodiversity. Yet, the same model can exhibit negative relationships between nestedness and biodiversity when examined in a distinct, plausible region of parameter space. We discuss steps towards identifying when network structure could, on its own, drive the resilience, sustainability, and even conservation of ecological communities. PMID:26632996

Stochastic Community Assembly: Does It Matter in Microbial Ecology?

PubMed

Zhou, Jizhong; Ning, Daliang

2017-12-01

Understanding the mechanisms controlling community diversity, functions, succession, and biogeography is a central, but poorly understood, topic in ecology, particularly in microbial ecology. Although stochastic processes are believed to play nonnegligible roles in shaping community structure, their importance relative to deterministic processes is hotly debated. The importance of ecological stochasticity in shaping microbial community structure is far less appreciated. Some of the main reasons for such heavy debates are the difficulty in defining stochasticity and the diverse methods used for delineating stochasticity. Here, we provide a critical review and synthesis of data from the most recent studies on stochastic community assembly in microbial ecology. We then describe both stochastic and deterministic components embedded in various ecological processes, including selection, dispersal, diversification, and drift. We also describe different approaches for inferring stochasticity from observational diversity patterns and highlight experimental approaches for delineating ecological stochasticity in microbial communities. In addition, we highlight research challenges, gaps, and future directions for microbial community assembly research. Copyright © 2017 American Society for Microbiology.

Invasive aquarium fish transform ecosystem nutrient dynamics

PubMed Central

Capps, Krista A.; Flecker, Alexander S.

2013-01-01

Trade of ornamental aquatic species is a multi-billion dollar industry responsible for the introduction of myriad fishes into novel ecosystems. Although aquarium invaders have the potential to alter ecosystem function, regulation of the trade is minimal and little is known about the ecosystem-level consequences of invasion for all but a small number of aquarium species. Here, we demonstrate how ecological stoichiometry can be used as a framework to identify aquarium invaders with the potential to modify ecosystem processes. We show that explosive growth of an introduced population of stoichiometrically unique, phosphorus (P)-rich catfish in a river in southern Mexico significantly transformed stream nutrient dynamics by altering nutrient storage and remineralization rates. Notably, changes varied between elements; the P-rich fish acted as net sinks of P and net remineralizers of nitrogen. Results from this study suggest species-specific stoichiometry may be insightful for understanding how invasive species modify nutrient dynamics when their population densities and elemental composition differ substantially from native organisms. Risk analysis for potential aquarium imports should consider species traits such as body stoichiometry, which may increase the likelihood that an invasion will alter the structure and function of ecosystems. PMID:23966642

Integrating a rangeland health assessment with successional management: A synergistic approach to EBIPM

USDA-ARS?s Scientific Manuscript database

Qualitative Rangeland Health Assessments are extremely useful because they provide a relative indication of resource problems on rangelands. Additionally, theSuccessional Management framework identifies three primary causes of plantcommunity change, ecological processes, and factors that modify thes...

Landscape moderation of biodiversity patterns and processes - eight hypotheses

USDA-ARS?s Scientific Manuscript database

Understanding how landscape characteristics affect local biodiversity patterns and ecological processes is critical for mitigating effects of global environmental change. In this review, we use knowledge gained from human-modified landscapes to suggest the following seven hypotheses, which we hope w...

Strong influence of regional species pools on continent-wide structuring of local communities.

PubMed

Lessard, Jean-Philippe; Borregaard, Michael K; Fordyce, James A; Rahbek, Carsten; Weiser, Michael D; Dunn, Robert R; Sanders, Nathan J

2012-01-22

There is a long tradition in ecology of evaluating the relative contribution of the regional species pool and local interactions on the structure of local communities. Similarly, a growing number of studies assess the phylogenetic structure of communities, relative to that in the regional species pool, to examine the interplay between broad-scale evolutionary and fine-scale ecological processes. Finally, a renewed interest in the influence of species source pools on communities has shown that the definition of the source pool influences interpretations of patterns of community structure. We use a continent-wide dataset of local ant communities and implement ecologically explicit source pool definitions to examine the relative importance of regional species pools and local interactions for shaping community structure. Then we assess which factors underlie systematic variation in the structure of communities along climatic gradients. We find that the average phylogenetic relatedness of species in ant communities decreases from tropical to temperate regions, but the strength of this relationship depends on the level of ecological realism in the definition of source pools. We conclude that the evolution of climatic niches influences the phylogenetic structure of regional source pools and that the influence of regional source pools on local community structure is strong.

[Ecological risk assessment of typical karst basin based on land use change: A case study of Lijiang River basin, Southern China].

PubMed

Hu, Jin Long; Zhou, Zhi Xiang; Teng, Ming Jun; Luo, Nan

2017-06-18

Taking Lijiang River basin as study area, and based on the remote sensing images of 1973, 1986, 2000 and 2013, the land-use data were extracted, the ecological risk index was constructed, and the characteristics of spatiotemporal variation of ecological risk were analyzed by "3S" technique. The results showed that land use structure of Lijiang River basin was under relatively reasonable state and it was constantly optimizing during 1973-2013. Overall, the ecological risk of Lijiang River basin was maintained at a low level. Lowest and lower ecological risk region was dominant in Lijiang River basin, but the area of highest ecological risk expanded quickly. The spatial distribution of ecological risk was basically stable and showed an obvious ring structure, which gra-dually decreased from the axis of Xingan County Town-Lingchuan County Town-Guilin City-Yangshuo County Town to other regions. Region with lowest ecological risk mainly distributed in natural mountain forest area of the north and mid-eastern parts of Lijiang River basin, and region with highe-st ecological risk concentrated in Guilin City. The ecological risk distribution of Lijiang River basin presented significant slope and altitude differences, and it decreased with increasing slope and altitude. During the study period, the area of low ecological risk converted to high ecological risk gra-dually decreased and vice versa. On the whole, the ecological risk tended to decline rapidly in the Lijiang River basin.

Theory of stability, and regulation and control of ecological system in oasis

NASA Astrophysics Data System (ADS)

Pan, Xiaoling; Chao, Jiping

2003-06-01

Starting with analysis on the evolving course of oasis and the characteristics and evolution of transitional zone between oasis and desert, in consideration of ecological elements including plant stomata resistance, area covered by vegetation, and physical elements including albedo of vegetation and bare soil, atmosphere temperature, and humidity, under the condition of the balance among net radiation flux, latent heat flux, and sensible heat flux, the following are calculated: temperatures of vegetation and bare soil in different conditions, as well as the evapotranspiration rate of ecosystem. Analysis on evapotranspiration rate indicates that it depends on both the climate of environment and the physiological and ecological conditions of plants. On certain conditions, the evapotranspiration rate of transitional zone between oasis and desert (i.e. area covered by vegetation less than 20%), in some parameter domains, appears in bifurcation or multiequilibrium state. Meanwhile, in such area, ecosystem is extremely unstable. Any minor change to the balance will cause either increase or reduction of area covered by vegetation in ecosystem, on the basis of discussion on the emergency of these phenomena. This paper is attempting to propose an effective way of destruction and rebuilt ecosystem in transitional zone. The way is to control the evaporation of plant through selecting anti-drought country plant with big stomata resistance, and modify the roughness of the underlying surface in ecosystem by establishing rational interspace structure of plant community, so as to put the degenerative ecosystem into the natural succession track. This primary theory is being verified through observation and analysis on historical data.

A Multicountry Ecological Study of Cancer Incidence Rates in 2008 with Respect to Various Risk-Modifying Factors

PubMed Central

Grant, William B.

2013-01-01

Observational and ecological studies are generally used to determine the presence of effect of cancer risk-modifying factors. Researchers generally agree that environmental factors such as smoking, alcohol consumption, poor diet, lack of physical activity, and low serum 25-hdyroxyvitamin D levels are important cancer risk factors. This ecological study used age-adjusted incidence rates for 21 cancers for 157 countries (87 with high-quality data) in 2008 with respect to dietary supply and other factors, including per capita gross domestic product, life expectancy, lung cancer incidence rate (an index for smoking), and latitude (an index for solar ultraviolet-B doses). The factors found to correlate strongly with multiple types of cancer were lung cancer (direct correlation with 12 types of cancer), energy derived from animal products (direct correlation with 12 types of cancer, inverse with two), latitude (direct correlation with six types, inverse correlation with three), and per capita gross national product (five types). Life expectancy and sweeteners directly correlated with three cancers, animal fat with two, and alcohol with one. Consumption of animal products correlated with cancer incidence with a lag time of 15–25 years. Types of cancer which correlated strongly with animal product consumption, tended to correlate weakly with latitude; this occurred for 11 cancers for the entire set of countries. Regression results were somewhat different for the 87 high-quality country data set and the 157-country set. Single-country ecological studies have inversely correlated nearly all of these cancers with solar ultraviolet-B doses. These results can provide guidance for prevention of cancer. PMID:24379012

Nest Predation Deviates from Nest Predator Abundance in an Ecologically Trapped Bird.

PubMed

Hollander, Franck A; Van Dyck, Hans; San Martin, Gilles; Titeux, Nicolas

2015-01-01

In human-modified environments, ecological traps may result from a preference for low-quality habitat where survival or reproductive success is lower than in high-quality habitat. It has often been shown that low reproductive success for birds in preferred habitat types was due to higher nest predator abundance. However, between-habitat differences in nest predation may only weakly correlate with differences in nest predator abundance. An ecological trap is at work in a farmland bird (Lanius collurio) that recently expanded its breeding habitat into open areas in plantation forests. This passerine bird shows a strong preference for forest habitat, but it has a higher nest success in farmland. We tested whether higher abundance of nest predators in the preferred habitat or, alternatively, a decoupling of nest predator abundance and nest predation explained this observed pattern of maladaptive habitat selection. More than 90% of brood failures were attributed to nest predation. Nest predator abundance was more than 50% higher in farmland, but nest predation was 17% higher in forest. Differences between nest predation on actual shrike nests and on artificial nests suggested that parent shrikes may facilitate nest disclosure for predators in forest more than they do in farmland. The level of caution by parent shrikes when visiting their nest during a simulated nest predator intrusion was the same in the two habitats, but nest concealment was considerably lower in forest, which contributes to explaining the higher nest predation in this habitat. We conclude that a decoupling of nest predator abundance and nest predation may create ecological traps in human-modified environments.

Nest Predation Deviates from Nest Predator Abundance in an Ecologically Trapped Bird

PubMed Central

Hollander, Franck A.; Van Dyck, Hans; San Martin, Gilles; Titeux, Nicolas

2015-01-01

In human-modified environments, ecological traps may result from a preference for low-quality habitat where survival or reproductive success is lower than in high-quality habitat. It has often been shown that low reproductive success for birds in preferred habitat types was due to higher nest predator abundance. However, between-habitat differences in nest predation may only weakly correlate with differences in nest predator abundance. An ecological trap is at work in a farmland bird (Lanius collurio) that recently expanded its breeding habitat into open areas in plantation forests. This passerine bird shows a strong preference for forest habitat, but it has a higher nest success in farmland. We tested whether higher abundance of nest predators in the preferred habitat or, alternatively, a decoupling of nest predator abundance and nest predation explained this observed pattern of maladaptive habitat selection. More than 90% of brood failures were attributed to nest predation. Nest predator abundance was more than 50% higher in farmland, but nest predation was 17% higher in forest. Differences between nest predation on actual shrike nests and on artificial nests suggested that parent shrikes may facilitate nest disclosure for predators in forest more than they do in farmland. The level of caution by parent shrikes when visiting their nest during a simulated nest predator intrusion was the same in the two habitats, but nest concealment was considerably lower in forest, which contributes to explaining the higher nest predation in this habitat. We conclude that a decoupling of nest predator abundance and nest predation may create ecological traps in human-modified environments. PMID:26624619

A multicountry ecological study of cancer incidence rates in 2008 with respect to various risk-modifying factors.

PubMed

Grant, William B

2013-12-27

Observational and ecological studies are generally used to determine the presence of effect of cancer risk-modifying factors. Researchers generally agree that environmental factors such as smoking, alcohol consumption, poor diet, lack of physical activity, and low serum 25-hdyroxyvitamin D levels are important cancer risk factors. This ecological study used age-adjusted incidence rates for 21 cancers for 157 countries (87 with high-quality data) in 2008 with respect to dietary supply and other factors, including per capita gross domestic product, life expectancy, lung cancer incidence rate (an index for smoking), and latitude (an index for solar ultraviolet-B doses). The factors found to correlate strongly with multiple types of cancer were lung cancer (direct correlation with 12 types of cancer), energy derived from animal products (direct correlation with 12 types of cancer, inverse with two), latitude (direct correlation with six types, inverse correlation with three), and per capita gross national product (five types). Life expectancy and sweeteners directly correlated with three cancers, animal fat with two, and alcohol with one. Consumption of animal products correlated with cancer incidence with a lag time of 15-25 years. Types of cancer which correlated strongly with animal product consumption, tended to correlate weakly with latitude; this occurred for 11 cancers for the entire set of countries. Regression results were somewhat different for the 87 high-quality country data set and the 157-country set. Single-country ecological studies have inversely correlated nearly all of these cancers with solar ultraviolet-B doses. These results can provide guidance for prevention of cancer.

Cyanobactins from Cyanobacteria: Current Genetic and Chemical State of Knowledge

PubMed Central

Martins, Joana; Vasconcelos, Vitor

2015-01-01

Cyanobacteria are considered to be one of the most promising sources of new, natural products. Apart from non-ribosomal peptides and polyketides, ribosomally synthesized and post-translationally modified peptides (RiPPs) are one of the leading groups of bioactive compounds produced by cyanobacteria. Among these, cyanobactins have sparked attention due to their interesting bioactivities and for their potential to be prospective candidates in the development of drugs. It is assumed that the primary source of cyanobactins is cyanobacteria, although these compounds have also been isolated from marine animals such as ascidians, sponges and mollusks. The aim of this review is to update the current knowledge of cyanobactins, recognized as being produced by cyanobacteria, and to emphasize their genetic clusters and chemical structures as well as their bioactivities, ecological roles and biotechnological potential. PMID:26580631

Temperate Snake Community in South America: Is Diet Determined by Phylogeny or Ecology?

PubMed Central

Etchepare, Eduardo G.

2015-01-01

Communities are complex and dynamic systems that change with time. The first attempts to explain how they were structured involve contemporary phenomena like ecological interactions between species (e.g., competition and predation) and led to the competition-predation hypothesis. Recently, the deep history hypothesis has emerged, which suggests that profound differences in the evolutionary history of organisms resulted in a number of ecological features that remain largely on species that are part of existing communities. Nevertheless, both phylogenetic structure and ecological interactions can act together to determine the structure of a community. Because diet is one of the main niche axes, in this study we evaluated, for the first time, the impact of ecological and phylogenetic factors on the diet of Neotropical snakes from the subtropical-temperate region of South America. Additionally, we studied their relationship with morphological and environmental aspects to understand the natural history and ecology of this community. A canonical phylogenetical ordination analysis showed that phylogeny explained most of the variation in diet, whereas ecological characters explained very little of this variation. Furthermore, some snakes that shared the habitat showed some degree of diet convergence, in accordance with the competition-predation hypothesis, although phylogeny remained the major determinant in structuring this community. The clade with the greatest variability was the subfamily Dipsadinae, whose members had a very different type of diet, based on soft-bodied invertebrates. Our results are consistent with the deep history hypothesis, and we suggest that the community under study has a deep phylogenetic effect that explains most of the variation in the diet. PMID:25945501

Increasing connectivity between metapopulation ecology and landscape ecology.

PubMed

Howell, Paige E; Muths, Erin; Hossack, Blake R; Sigafus, Brent H; Chandler, Richard B

2018-05-01

Metapopulation ecology and landscape ecology aim to understand how spatial structure influences ecological processes, yet these disciplines address the problem using fundamentally different modeling approaches. Metapopulation models describe how the spatial distribution of patches affects colonization and extinction, but often do not account for the heterogeneity in the landscape between patches. Models in landscape ecology use detailed descriptions of landscape structure, but often without considering colonization and extinction dynamics. We present a novel spatially explicit modeling framework for narrowing the divide between these disciplines to advance understanding of the effects of landscape structure on metapopulation dynamics. Unlike previous efforts, this framework allows for statistical inference on landscape resistance to colonization using empirical data. We demonstrate the approach using 11 yr of data on a threatened amphibian in a desert ecosystem. Occupancy data for Lithobates chiricahuensis (Chiricahua leopard frog) were collected on the Buenos Aires National Wildlife Refuge (BANWR), Arizona, USA from 2007 to 2017 following a reintroduction in 2003. Results indicated that colonization dynamics were influenced by both patch characteristics and landscape structure. Landscape resistance increased with increasing elevation and distance to the nearest streambed. Colonization rate was also influenced by patch quality, with semi-permanent and permanent ponds contributing substantially more to the colonization of neighboring ponds relative to intermittent ponds. Ponds that only hold water intermittently also had the highest extinction rate. Our modeling framework can be widely applied to understand metapopulation dynamics in complex landscapes, particularly in systems in which the environment between habitat patches influences the colonization process. © 2018 by the Ecological Society of America.

Factorial Structure of the New Ecological Paradigm Scale in Two French Samples

ERIC Educational Resources Information Center

Fleury-Bahi, Ghozlane; Marcouyeux, Aurore; Renard, Elise; Roussiau, Nicolas

2015-01-01

The principal objective of this research is to test the factorial structure of the New Ecological Paradigm scale on a population of men and women residing in France. The tested model is a second-order factorial model. This factorial structure is evaluated on two separate samples to test the stability of the solution (a first sample of 253…

Social-ecological research in urban natural areas: an emergent process for integration

Treesearch

Michelle L. Johnson; D. S. Novem Auyeung; Nancy F. Sonti; Clara C. Pregitzer; Heather L. McMillen; Richard Hallett; Lindsay K. Campbell; Helen M. Forgione; Mina Kim; Sarah Charlop-Powers; Erika S. Svendsen

2018-01-01

Understanding the structure and function of urban landscapes requires integrating social and ecological research. Here, we integrate parallel social and ecological assessments of natural areas within New York City. We examined social data (from a rapid assessment of park use and meaning, collected at a park zone level) alongside ecological data (froma plot-based...

Conserving intertidal habitats: What is the potential of ecological engineering to mitigate impacts of coastal structures?

NASA Astrophysics Data System (ADS)

Perkins, Matthew J.; Ng, Terence P. T.; Dudgeon, David; Bonebrake, Timothy C.; Leung, Kenneth M. Y.

2015-12-01

Globally, coastlines are under pressure as coastal human population growth and urbanization continues, while climatic change leads to stormier seas and rising tides. These trends create a strong and sustained demand for land reclamation and infrastructure protection in coastal areas, requiring engineered coastal defence structures such as sea walls. Here, we review the nature of ecological impacts of coastal structures on intertidal ecosystems, seek to understand the extent to which ecological engineering can mitigate these impacts, and evaluate the effectiveness of mitigation as a tool to contribute to conservation of intertidal habitats. By so doing, we identify critical knowledge gaps to inform future research. Coastal structures alter important physical, chemical and biological processes of intertidal habitats, and strongly impact community structure, inter-habitat linkages and ecosystem services while also driving habitat loss. Such impacts occur diffusely across localised sites but scale to significant regional and global levels. Recent advances in ecological engineering have focused on developing habitat complexity on coastal structures to increase biodiversity. 'Soft' engineering options maximise habitat complexity through inclusion of natural materials, species and processes, while simultaneously delivering engineering objectives such as coastal protection. Soft options additionally sustain multiple services, providing greater economic benefits for society, and resilience to climatic change. Currently however, a lack of inclusion and economic undervaluation of intertidal ecosystem services may undermine best practice in coastline management. Importantly, reviewed evidence shows mitigation and even restoration do not support intertidal communities or processes equivalent to pre-disturbance conditions. Crucially, an absence of comprehensive empirical baseline biodiversity data, or data comprising additional ecological parameters such as ecosystem functions and services, prohibits quantification of absolute and relative magnitudes of ecological impacts due to coastal structures or effectiveness of mitigation interventions. This knowledge deficit restricts evaluation of the potential of ecological engineering to contribute to conservation policies for intertidal habitats. To improve mitigation design and effectiveness, a greater focus on in-situ research is needed, requiring stronger and timely collaboration between government agencies, construction partners and research scientists.

ENVIRONMENTAL MONITORING AND ASSESSMENT OF A GREAT RIVER ECOSYSTEM: THE UPPER MISSOURI RIVER PILOT

EPA Science Inventory

The Great River Ecosystems (GREs) are extensively modified physically, hydrologically, and chemically and are not receiving adequate protection to prevent further habitat degradation and loss of biotic integrity. In the United States, ecological monitoring and assessment of the G...

Exemplary Programs in Secondary School Biology.

ERIC Educational Resources Information Center

McComas, William F.; Penick, John E.

1989-01-01

Summarizes 10 exemplary programs which address topics on individualized biology, a modified team approach, limnology, physical anthropology, the relevance of biology to society, ecology, and health. Provides names and addresses of contact persons for further information. Units cover a broad range of abilities and activities. (RT)

Fine scale mapping of the structure and composition of the Elkhorn Slough (California, USA) tidal plume

NASA Astrophysics Data System (ADS)

Fischer, Andrew M.; Ryan, John P.; Rienecker, Erich V.

2017-01-01

Fine scale mapping of the structure and composition of a tidal ebb plume from a highly modified coastal lagoon (Elkhorn Slough, California, USA) was conducted by combining in situ, observational data sets from surface underway mapping, autonomous underwater vehicle (AUV) profiles, drifter tracking and the analysis of plume structure indices. The results reveal a 6-m-deep, jet-like, sediment laden plume extending one km offshore at low tide, which becomes entrained in the prevailing nearshore circulation. The plume that exits the slough is significantly different from the water that enters the slough. The rapidly evolving discharge plume is associated with elevated and highly correlated (r = 0.93) concentrations of dissolved organic matter and nitrate. While dissolved constituents remain in the shallow plume and are transported northward with the prevailing current, sediment may settle quickly through the water column and can be transported southwestward with the littoral currents. This study illustrates the applications of AUVs, when coupled with additional datasets, for generating higher resolution observational snapshots of dynamic and ephemeral tidal plumes. The results provide unique perspective on small-scale dynamics of an estuarine plume and its influence on coastal ecology.

Macroclimatic change expected to transform coastal wetland ecosystems this century

USGS Publications Warehouse

Gabler, Christopher A.; Osland, Michael J.; Grace, James B.; Stagg, Camille L.; Day, Richard H.; Hartley, Stephen B.; Enwright, Nicholas M.; From, Andrew; McCoy, Meagan L.; McLeod, Jennie L.

2017-01-01

Coastal wetlands, existing at the interface between land and sea, are highly vulnerable to climate change. Macroclimate (for example, temperature and precipitation regimes) greatly influences coastal wetland ecosystem structure and function. However, research on climate change impacts in coastal wetlands has concentrated primarily on sea-level rise and largely ignored macroclimatic drivers, despite their power to transform plant community structure and modify ecosystem goods and services. Here, we model wetland plant community structure based on macroclimate using field data collected across broad temperature and precipitation gradients along the northern Gulf of Mexico coast. Our analyses quantify strongly nonlinear temperature thresholds regulating the potential for marsh-to-mangrove conversion. We also identify precipitation thresholds for dominance by various functional groups, including succulent plants and unvegetated mudflats. Macroclimate-driven shifts in foundation plant species abundance will have large effects on certain ecosystem goods and services. Based on current and projected climatic conditions, we project that transformative ecological changes are probable throughout the region this century, even under conservative climate scenarios. Coastal wetland ecosystems are functionally similar worldwide, so changes in this region are indicative of potential future changes in climatically similar regions globally.

Significance of treated agrowaste residue and autochthonous inoculates (Arbuscular mycorrhizal fungi and Bacillus cereus) on bacterial community structure and phytoextraction to remediate soils contaminated with heavy metals.

PubMed

Azcón, Rosario; Medina, Almudena; Roldán, Antonio; Biró, Borbála; Vivas, Astrid

2009-04-01

In this study, we analyzed the impact of treatments such as Aspergillus niger-treated sugar beet waste (SB), PO4(3-) fertilization and autochthonous inoculants [arbuscular mycorrhizal (AM) fungi and Bacillus cereus], on the bacterial community structure in a soils contaminated with heavy metals as well as, the effectiveness on plant growth (Trifolium repens). The inoculation with AM fungi in SB amended soil, increased plant growth similarly to PO4(3-) addition, and both treatments matched in P acquisition but bacterial biodiversity estimated by denaturing gradient gel electrophoresis of amplified 16S rDNA sequences, was more stimulated by the presence of the AM fungus than by PO4(3-) fertilization. The SB amendment plus AM inoculation increased the microbial diversity by 233% and also changed (by 215%) the structure of the bacterial community. The microbial inoculants and amendment used favoured plant growth and the phytoextraction process and concomitantly modified bacterial community in the rhizosphere; thus they can be used for remediation. Therefore, the understanding of such microbial ecological aspects is important for phytoremediation and the recovery of contaminated soils.

Mixed infections and the competitive fitness of faster-acting genetically modified viruses

PubMed Central

Zwart, Mark P; Van Der Werf, Wopke; Van Oers, Monique M; Hemerik, Lia; Van Lent, Jan M V; De Visser, J Arjan G M; Vlak, Just M; Cory, Jenny S

2009-01-01

Faster-acting recombinant baculoviruses have shown potential for improved suppression of insect pests, but their ecological impact on target and nontarget hosts and naturally occurring pathogens needs to be assessed. Previous studies have focused on the fitness of recombinants at the between-hosts level. However, the population structure of the transmission stages will also be decided by within-host selection. Here we have experimentally quantified the within-host competitive fitness of a fast-acting recombinant Autographa californica multicapsid nucleopolyhedrovirus missing the endogenous egt gene (vEGTDEL), by means of direct competition in single- and serial-passage experiments with its parental virus. Quantitative real-time PCR was employed to determine the ratio of these two viruses in passaged mixtures. We found that vEGTDEL had reduced within-host fitness: per passage the ratio of wild type to vEGTDEL was on average enhanced by a factor of 1.53 (single passage) and 1.68 (serial passage). There is also frequency-dependence: the higher the frequency of vEGTDEL, the stronger the selection against it is. Additionally, the virus ratio is a predictor of time to host death and virus yield. Our results show that egt is important to within-host fitness and allow for a more complete assessment of the ecological impact of recombinant baculovirus release. PMID:25567862

The shapes of bird beaks are highly controlled by nondietary factors

PubMed Central

Bright, Jen A.; Marugán-Lobón, Jesús; Cobb, Samuel N.

2016-01-01

Bird beaks are textbook examples of ecological adaptation to diet, but their shapes are also controlled by genetic and developmental histories. To test the effects of these factors on the avian craniofacial skeleton, we conducted morphometric analyses on raptors, a polyphyletic group at the base of the landbird radiation. Despite common perception, we find that the beak is not an independently targeted module for selection. Instead, the beak and skull are highly integrated structures strongly regulated by size, with axes of shape change linked to the actions of recently identified regulatory genes. Together, size and integration account for almost 80% of the shape variation seen between different species to the exclusion of morphological dietary adaptation. Instead, birds of prey use size as a mechanism to modify their feeding ecology. The extent to which shape variation is confined to a few major axes may provide an advantage in that it facilitates rapid morphological evolution via changes in body size, but may also make raptors especially vulnerable when selection pressures act against these axes. The phylogenetic position of raptors suggests that this constraint is prevalent in all landbirds and that breaking the developmental correspondence between beak and braincase may be the key novelty in classic passerine adaptive radiations. PMID:27125856

The shapes of bird beaks are highly controlled by nondietary factors.

PubMed

Bright, Jen A; Marugán-Lobón, Jesús; Cobb, Samuel N; Rayfield, Emily J

2016-05-10

Bird beaks are textbook examples of ecological adaptation to diet, but their shapes are also controlled by genetic and developmental histories. To test the effects of these factors on the avian craniofacial skeleton, we conducted morphometric analyses on raptors, a polyphyletic group at the base of the landbird radiation. Despite common perception, we find that the beak is not an independently targeted module for selection. Instead, the beak and skull are highly integrated structures strongly regulated by size, with axes of shape change linked to the actions of recently identified regulatory genes. Together, size and integration account for almost 80% of the shape variation seen between different species to the exclusion of morphological dietary adaptation. Instead, birds of prey use size as a mechanism to modify their feeding ecology. The extent to which shape variation is confined to a few major axes may provide an advantage in that it facilitates rapid morphological evolution via changes in body size, but may also make raptors especially vulnerable when selection pressures act against these axes. The phylogenetic position of raptors suggests that this constraint is prevalent in all landbirds and that breaking the developmental correspondence between beak and braincase may be the key novelty in classic passerine adaptive radiations.

African migrant patients' trust in Chinese physicians: a social ecological approach to understanding patient-physician trust.

PubMed

McLaughlin, Megan M; Simonson, Louis; Zou, Xia; Ling, Li; Tucker, Joseph D

2015-01-01

Patient trust in physicians is a critical determinant of health seeking behaviors, medication adherence, and health outcomes. A crisis of interpersonal trust exists in China, extending throughout multiple social spheres, including the healthcare system. At the same time, with increased migration from Africa to China in the last two decades, Chinese physicians must establish mutual trust with an increasingly diverse patient population. We undertook a qualitative study to identify factors affecting African migrants' trust in Chinese physicians and to identify potential mechanisms for promoting trust. We conducted semi-structured, in-depth interviews with 40 African migrants in Guangzhou, China. A modified version of the social ecological model was used as a theoretical framework. At the patient-physician level, interpersonal treatment, technical competence, perceived commitment and motive, and language concordance were associated with enhanced trust. At the health system level, two primary factors influenced African migrants' trust in their physicians: the fee-for-service payment system and lack of continuity with any one physician. Patients' social networks and the broader socio-cultural context of interactions between African migrants and Chinese locals also influenced patients' trust of their physicians. These findings demonstrate the importance of factors beyond the immediate patient-physician interaction and suggest opportunities to promote trust through health system interventions.

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

Simulating topographic controls on the abundance of larch forest in eastern Siberia, and its consequences under changing climate

NASA Astrophysics Data System (ADS)

Sato, H.; Kobayashi, H.

2017-12-01

In eastern Siberia, larches (Larix spp.) often exist in pure stands, constructing the world's largest coniferous forest, of which changes can significantly affect the earth's albedo and the global carbon balance. Our previous studies tried to reconstruct this vegetation, aiming to forecast its structures and functions under changing climate (1, 2). In previous studies of simulating vegetation at large geographical scales, the examining area is divided into coarse grid cells such as 0.5 × 0.5 degree resolution, and topographical heterogeneities within each grid cell are just ignored. However, in Siberian larch area, which is located on the environmental edge of existence of forest ecosystem, abundance of larch trees largely depends on topographic condition at the scale of tens to hundreds meters. In our preliminary analysis, we found a quantitative pattern that topographic properties controls the abundance of larch forest via both drought and flooding stresses in eastern Siberia. We, therefore, refined the hydrological sub-model of our dynamic vegetation model SEIB-DGVM, and validated whether the modified model can reconstruct the pattern, examined its impact on the estimation of biomass and vegetation productivity under the current and forecasted future climatic conditions. -- References --1. Sato, H., et al. (2010). "Simulation study of the vegetation structure and function in eastern Siberian larch forests using the individual-based vegetation model SEIB-DGVM." Forest Ecology and Management 259(3): 301-311. 2. Sato, H., et al. (2016). "Endurance of larch forest ecosystems in eastern Siberia under warming trends." Ecology and Evolution

Pre-Columbian agricultural landscapes, ecosystem engineers, and self-organized patchiness in Amazonia.

PubMed

McKey, Doyle; Rostain, Stéphen; Iriarte, José; Glaser, Bruno; Birk, Jago Jonathan; Holst, Irene; Renard, Delphine

2010-04-27

The scale and nature of pre-Columbian human impacts in Amazonia are currently hotly debated. Whereas pre-Columbian people dramatically changed the distribution and abundance of species and habitats in some parts of Amazonia, their impact in other parts is less clear. Pioneer research asked whether their effects reached even further, changing how ecosystems function, but few in-depth studies have examined mechanisms underpinning the resilience of these modifications. Combining archeology, archeobotany, paleoecology, soil science, ecology, and aerial imagery, we show that pre-Columbian farmers of the Guianas coast constructed large raised-field complexes, growing on them crops including maize, manioc, and squash. Farmers created physical and biogeochemical heterogeneity in flat, marshy environments by constructing raised fields. When these fields were later abandoned, the mosaic of well-drained islands in the flooded matrix set in motion self-organizing processes driven by ecosystem engineers (ants, termites, earthworms, and woody plants) that occur preferentially on abandoned raised fields. Today, feedbacks generated by these ecosystem engineers maintain the human-initiated concentration of resources in these structures. Engineer organisms transport materials to abandoned raised fields and modify the structure and composition of their soils, reducing erodibility. The profound alteration of ecosystem functioning in these landscapes coconstructed by humans and nature has important implications for understanding Amazonian history and biodiversity. Furthermore, these landscapes show how sustainability of food-production systems can be enhanced by engineering into them follows that maintain ecosystem services and biodiversity. Like anthropogenic dark earths in forested Amazonia, these self-organizing ecosystems illustrate the ecological complexity of the legacy of pre-Columbian land use.

Pre-Columbian agricultural landscapes, ecosystem engineers, and self-organized patchiness in Amazonia

PubMed Central

McKey, Doyle; Rostain, Stéphen; Iriarte, José; Glaser, Bruno; Birk, Jago Jonathan; Holst, Irene; Renard, Delphine

2010-01-01

The scale and nature of pre-Columbian human impacts in Amazonia are currently hotly debated. Whereas pre-Columbian people dramatically changed the distribution and abundance of species and habitats in some parts of Amazonia, their impact in other parts is less clear. Pioneer research asked whether their effects reached even further, changing how ecosystems function, but few in-depth studies have examined mechanisms underpinning the resilience of these modifications. Combining archeology, archeobotany, paleoecology, soil science, ecology, and aerial imagery, we show that pre-Columbian farmers of the Guianas coast constructed large raised-field complexes, growing on them crops including maize, manioc, and squash. Farmers created physical and biogeochemical heterogeneity in flat, marshy environments by constructing raised fields. When these fields were later abandoned, the mosaic of well-drained islands in the flooded matrix set in motion self-organizing processes driven by ecosystem engineers (ants, termites, earthworms, and woody plants) that occur preferentially on abandoned raised fields. Today, feedbacks generated by these ecosystem engineers maintain the human-initiated concentration of resources in these structures. Engineer organisms transport materials to abandoned raised fields and modify the structure and composition of their soils, reducing erodibility. The profound alteration of ecosystem functioning in these landscapes coconstructed by humans and nature has important implications for understanding Amazonian history and biodiversity. Furthermore, these landscapes show how sustainability of food-production systems can be enhanced by engineering into them fallows that maintain ecosystem services and biodiversity. Like anthropogenic dark earths in forested Amazonia, these self-organizing ecosystems illustrate the ecological complexity of the legacy of pre-Columbian land use. PMID:20385814

Testing Natureserve's ecological integrity assessment model in Michigan and Indiana

EPA Science Inventory

NatureServe, in partnership with member programs from the Natural Heritage Network and federal agencies, has developed an assessment of ecosystems condition, structured around the concept of ecological integrity. Our multi-metric approach for our Ecological Integrity Assessment m...

Adopting an ecological view of metropolitan landscape: the case of "three circles" system for ecological construction and restoration in Beijing area.

PubMed

Zhang, Feng; Zhang, Xin-shi

2004-01-01

Ecological construction and restoration for sustainable development are now a driving paradigm. It is increasingly recognized that ecological principles, especially landscape ecology theory, are not only necessary but also essential to maintain the long-term sustainability worldwide. Key landscape ecology principles-element, structure and process, dynamics, heterogeneity, hierarchies, connectivity, place and time were reviewed, and use Beijing area as a case study to illustrate how these principles might be applied to ecological construction and restoration, to eventually achieve sustainability. An example to more effectively incorporate the ecological principles in sustainable planning in China was presented.

Grazers structure the bacterial and algal diversity of aquatic metacommunities.

PubMed

Birtel, Julia; Matthews, Blake

2016-12-01

Consumers can have strong effects on the biotic and abiotic dynamics of spatially-structured ecosystems. In metacommunities, dispersing consumers can alter local assembly dynamics either directly through trophic interactions or indirectly by modifying local environmental conditions. In aquatic systems, very little is known about how key grazers, such as Daphnia, structure the microbial diversity of metacommunities and influence bacterial-mediated ecosystem functions. In an outdoor mesocosm experiment with replicate metacommunities (two 300 L mesocosms), we tested how the presence and absence of Daphnia and the initial density of the microbial community (manipulated via dilution) influenced the diversity and community structure of algae and bacteria, and several ecosystem properties (e.g., pH, dissolved substances) and functions (e.g., enzyme activity, respiration). We found that Daphnia strongly affected the local and regional diversity of both phytoplankton and bacteria, the taxonomic composition of bacterial communities, the biomass of algae, and ecosystem metabolism (i.e., respiration). Diluting the microbial inoculum (0.2-5 μm size fraction) to the metacommunities increased local phytoplankton diversity, decreased bacteria beta-diversity, and changed the relative abundance of bacterial classes. Changes in the rank abundance of different bacterial groups exhibited phylogenetic signal, implying that closely related bacteria species might share similar responses to the presence of Daphnia. © 2016 by the Ecological Society of America.

Reconstructing past ecological networks: the reconfiguration of seed-dispersal interactions after megafaunal extinction.

PubMed

Pires, Mathias M; Galetti, Mauro; Donatti, Camila I; Pizo, Marco A; Dirzo, Rodolfo; Guimarães, Paulo R

2014-08-01

The late Quaternary megafaunal extinction impacted ecological communities worldwide, and affected key ecological processes such as seed dispersal. The traits of several species of large-seeded plants are thought to have evolved in response to interactions with extinct megafauna, but how these extinctions affected the organization of interactions in seed-dispersal systems is poorly understood. Here, we combined ecological and paleontological data and network analyses to investigate how the structure of a species-rich seed-dispersal network could have changed from the Pleistocene to the present and examine the possible consequences of such changes. Our results indicate that the seed-dispersal network was organized into modules across the different time periods but has been reconfigured in different ways over time. The episode of megafaunal extinction and the arrival of humans changed how seed dispersers were distributed among network modules. However, the recent introduction of livestock into the seed-dispersal system partially restored the original network organization by strengthening the modular configuration. Moreover, after megafaunal extinctions, introduced species and some smaller native mammals became key components for the structure of the seed-dispersal network. We hypothesize that such changes in network structure affected both animal and plant assemblages, potentially contributing to the shaping of modern ecological communities. The ongoing extinction of key large vertebrates will lead to a variety of context-dependent rearranged ecological networks, most certainly affecting ecological and evolutionary processes.

Experience with environmental issues in GM crop production and the likely future scenarios.

PubMed

Gaugitsch, Helmut

2002-02-28

In the Cartagena Protocol on Biosafety, standards for risk assessment of genetically modified organisms (GMOs) have been set. The criteria and information basis for the risk assessment of GMOs have been modified by the EU Directive 2001/18/EC. Various approaches to further improve the criteria for environmental risk assessment of GMOs are described in this study. Reports on the ecological impacts of the cultivation of certain non-transgenic crop plants with novel or improved traits as analogy models to transgenic plants showed that the effects of agricultural practice can be at least equally important as the effects of gene transfer and invasiveness, although the latter currently play a major role in risk assessment of transgenic crops. Based on these results the applicability of the methodology of 'Life Cycle Analysis (LCA)' for genetically modified plants in comparison with conventionally bred and organically grown crop plants was evaluated. The methodology was regarded as applicable with some necessary future improvements. In current projects, the assessment of toxicology and allergenicity of GM crops are analysed, and suggestions for standardization are developed. Based on results and recommendations from these efforts there are still the challenges of how to operationalize the precautionary principle and how to take into account ecologically sensitive ecosystems, including centres of origin and centres of genetic diversity.

Ecological evaluation of an experimental beneficial use scheme for dredged sediment disposal in shallow tidal waters.

PubMed

van der Wal, Daphne; Forster, Rodney M; Rossi, Francesca; Hummel, Herman; Ysebaert, Tom; Roose, Frederik; Herman, Peter M J

2011-01-01

An experiment was performed to test an alternative dredging strategy for the Westerschelde estuary. Clean sand dredged from the navigation channel was disposed seawards of an eroding intertidal flat in order to modify morphology and hydrodynamics, improving the multi-channel system with ecologically productive shallow water habitat. Five years of intensive monitoring revealed that part of the disposed sediment moved slowly towards the flat, increasing the very shallow subtidal and intertidal area, as planned. The sand in the impact zone became gradually finer after disposal, possibly due to reduced current velocities. Nevertheless, no changes in macrobenthic biomass, density, species richness and composition were detected in the subtidal zone, also demonstrating rapid macrobenthic recovery. In the intertidal zone, no ecological effects could be revealed superimposed on trends associated with long-term sediment fining. Thus, despite morphological success and absence of detected negative ecological impacts of the experiment, new beneficial habitat was not created. Copyright © 2010 Elsevier Ltd. All rights reserved.

Nectar yeasts: a natural microcosm for ecology.

PubMed

Chappell, Callie R; Fukami, Tadashi

2018-06-01

The species of yeasts that colonize floral nectar can modify the mutualistic relationships between plants and pollinators by changing the chemical properties of nectar. Recent evidence supporting this possibility has led to increased interest among ecologists in studying these fungi as well as the bacteria that interact with them in nectar. Although not fully explored, nectar yeasts also constitute a promising natural microcosm that can be used to facilitate development of general ecological theory. We discuss the methodological and conceptual advantages of using nectar yeasts from this perspective, including simplicity of communities, tractability of dispersal, replicability of community assembly, and the ease with which the mechanisms of species interactions can be studied in complementary experiments conducted in the field and the laboratory. To illustrate the power of nectar yeasts as a study system, we discuss several topics in community ecology, including environmental filtering, priority effects, and metacommunity dynamics. An exciting new direction is to integrate metagenomics and comparative genomics into nectar yeast research to address these fundamental ecological topics. Copyright © 2018 John Wiley & Sons, Ltd.

Investigation and optimization of performance of nano-scale Stirling refrigerator using working fluid as Maxwell-Boltzmann gases

NASA Astrophysics Data System (ADS)

Ahmadi, Mohammad H.; Amin Nabakhteh, Mohammad; Ahmadi, Mohammad-Ali; Pourfayaz, Fathollah; Bidi, Mokhtar

2017-10-01

The motivation behind this work is to explore a nanoscale irreversible Stirling refrigerator with respect to size impacts and shows two novel thermo-ecological criteria. Two distinct strategies were suggested in the optimization process and the consequences of every strategy were examined independently. In the primary strategy, with the purpose of maximizing the energetic sustainability index and modified the ecological coefficient of performance (MECOP) and minimizing the dimensionless Ecological function, a multi-objective optimization algorithm (MOEA) was used. In the second strategy, with the purpose of maximizing the ECOP and MECOP and minimizing the dimensionless Ecological function, a MOEA was used. To conclude the final solution from each strategy, three proficient decision makers were utilized. Additionally, to quantify the deviation of the results gained from each decision makers, two different statistical error indexes were employed. Finally, based on the comparison between the results achieved from proposed scenarios reveals that by maximizing the MECOP the maximum values of ESI, ECOP, and a minimum of ecfare achieved.

What can ecosystems learn? Expanding evolutionary ecology with learning theory.

PubMed

Power, Daniel A; Watson, Richard A; Szathmáry, Eörs; Mills, Rob; Powers, Simon T; Doncaster, C Patrick; Czapp, Błażej

2015-12-08

The structure and organisation of ecological interactions within an ecosystem is modified by the evolution and coevolution of the individual species it contains. Understanding how historical conditions have shaped this architecture is vital for understanding system responses to change at scales from the microbial upwards. However, in the absence of a group selection process, the collective behaviours and ecosystem functions exhibited by the whole community cannot be organised or adapted in a Darwinian sense. A long-standing open question thus persists: Are there alternative organising principles that enable us to understand and predict how the coevolution of the component species creates and maintains complex collective behaviours exhibited by the ecosystem as a whole? Here we answer this question by incorporating principles from connectionist learning, a previously unrelated discipline already using well-developed theories on how emergent behaviours arise in simple networks. Specifically, we show conditions where natural selection on ecological interactions is functionally equivalent to a simple type of connectionist learning, 'unsupervised learning', well-known in neural-network models of cognitive systems to produce many non-trivial collective behaviours. Accordingly, we find that a community can self-organise in a well-defined and non-trivial sense without selection at the community level; its organisation can be conditioned by past experience in the same sense as connectionist learning models habituate to stimuli. This conditioning drives the community to form a distributed ecological memory of multiple past states, causing the community to: a) converge to these states from any random initial composition; b) accurately restore historical compositions from small fragments; c) recover a state composition following disturbance; and d) to correctly classify ambiguous initial compositions according to their similarity to learned compositions. We examine how the formation of alternative stable states alters the community's response to changing environmental forcing, and we identify conditions under which the ecosystem exhibits hysteresis with potential for catastrophic regime shifts. This work highlights the potential of connectionist theory to expand our understanding of evo-eco dynamics and collective ecological behaviours. Within this framework we find that, despite not being a Darwinian unit, ecological communities can behave like connectionist learning systems, creating internal conditions that habituate to past environmental conditions and actively recalling those conditions.

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.

A CONCEPTUAL MODEL FOR MULTI-SCALAR ASSESSMENTS OF ESTUARINE ECOLOGICAL INTEGRITY

EPA Science Inventory

A conceptual model was developed that relates an estuarine system's anthropogenic inputs to it's ecological integrity. Ecological integrity is operationally defined as an emergent property of an ecosystem that exists when the structural components are complete and the functional ...

Genesis, goals and achievements of Long-Term Ecological Research at the global scale: A critical review of ILTER and future directions.

PubMed

Mirtl, M; T Borer, E; Djukic, I; Forsius, M; Haubold, H; Hugo, W; Jourdan, J; Lindenmayer, D; McDowell, W H; Muraoka, H; Orenstein, D E; Pauw, J C; Peterseil, J; Shibata, H; Wohner, C; Yu, X; Haase, P

2018-06-01

Since its founding in 1993 the International Long-term Ecological Research Network (ILTER) has gone through pronounced development phases. The current network comprises 44 active member LTER networks representing 700 LTER Sites and ~80 LTSER Platforms across all continents, active in the fields of ecosystem, critical zone and socio-ecological research. The critical challenges and most important achievements of the initial phase have now become state-of-the-art in networking for excellent science. At the same time increasing integration, accelerating technology, networking of resources and a strong pull for more socially relevant scientific information have been modifying the mission and goals of ILTER. This article provides a critical review of ILTER's mission, goals, development and impacts. Major characteristics, tools, services, partnerships and selected examples of relative strengths relevant for advancing ILTER are presented. We elaborate on the tradeoffs between the needs of the scientific community and stakeholder expectations. The embedding of ILTER in an increasingly collaborative landscape of global environmental observation and ecological research networks and infrastructures is also reflected by developments of pioneering regional and national LTER networks such as SAEON in South Africa, CERN/CEOBEX in China, TERN in Australia or eLTER RI in Europe. The primary role of ILTER is currently seen as a mechanism to investigate ecosystem structure, function, and services in response to a wide range of environmental forcings using long-term, place-based research. We suggest four main fields of activities and advancements for the next decade through development/delivery of a: (1) Global multi-disciplinary community of researchers and research institutes; (2) Strategic global framework and strong partnerships in ecosystem observation and research; (3) Global Research Infrastructure (GRI); and (4) a scientific knowledge factory for societally relevant information on sustainable use of natural resources. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

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.

Prediction of biodiversity hotspots in the Anthropocene: The case of veteran oaks.

PubMed

Skarpaas, Olav; Blumentrath, Stefan; Evju, Marianne; Sverdrup-Thygeson, Anne

2017-10-01

Over the past centuries, humans have transformed large parts of the biosphere, and there is a growing need to understand and predict the distribution of biodiversity hotspots influenced by the presence of humans. Our basic hypothesis is that human influence in the Anthropocene is ubiquitous, and we predict that biodiversity hot spot modeling can be improved by addressing three challenges raised by the increasing ecological influence of humans: (i) anthropogenically modified responses to individual ecological factors, (ii) fundamentally different processes and predictors in landscape types shaped by different land use histories and (iii) a multitude and complexity of natural and anthropogenic processes that may require many predictors and even multiple models in different landscape types. We modeled the occurrence of veteran oaks in Norway, and found, in accordance with our basic hypothesis and predictions, that humans influence the distribution of veteran oaks throughout its range, but in different ways in forests and open landscapes. In forests, geographical and topographic variables related to the oak niche are still important, but the occurrence of veteran oaks is shifted toward steeper slopes, where logging is difficult. In open landscapes, land cover variables are more important, and veteran oaks are more common toward the north than expected from the fundamental oak niche. In both landscape types, multiple predictor variables representing ecological and human-influenced processes were needed to build a good model, and several models performed almost equally well. Models accounting for the different anthropogenic influences on landscape structure and processes consistently performed better than models based exclusively on natural biogeographical and ecological predictors. Thus, our results for veteran oaks clearly illustrate the challenges to distribution modeling raised by the ubiquitous influence of humans, even in a moderately populated region, but also show that predictions can be improved by explicitly addressing these anthropogenic complexities.

Hydromorphological adjustments and re-adjustments of low energy rivers in a sub-urban catchment following historical engineering and recent urbanization

NASA Astrophysics Data System (ADS)

Jugie, Marion; Gob, Frédéric; Slawson, Deborah; Le-Coeur, Charles

2014-05-01

The EU Water Framework Directive (WFD, October 2000) mandated that the Member States of the European Union achieve the general objective of protection of aquatic ecology by 2015. European rivers and streams have to attain "good ecological status" through the preservation and restoration of aquatic environments. Member will have to ensure environmental continuity through "the adequate distribution of fish species and transport of sediments". In France, more than 61,000 transverse structures - mill dams, weirs, diversion gates - have been identified on rivers as being obstacles to ecological and sedimentary continuity. Because of their historical occupation by societies, rivers flowing in the Paris area have long been anthropized and artificialized. River courses, channel shape, sediment transport and hydrological regime modifications have tremendously transformed the hydrosystems surrounding the city of Paris. The Merantaise's catchment is one of this low energy river watershed, near Paris, that have been modified by historical engineering, especially during medieval-modern times and by the building of the Versailles Castle (XVIIth century). The hydraulic infrastructures are still there and impact the hydromorphogical conditions of the river (incision, lateral erosion, …). In addition to these ancient pressures a rapid and massive urbanization of the suburban areas has applied a new type of constraint to the hydrosystems in recent decades. This undermines the balance that was established following ancient engineering and disturbs the current functioning of the valley. These new types of land occupation have significantly altered the ecological circumstances and transformed the hydrological responses of rivers. In this study, we therefore seek to understand these processes of successive adjustments (ancient and recent) of a small river from the urban margins of the Orge watershed (to the south of Paris). We use a multi-scalar spatial and temporal approach to reconstruct the hydromorphological circumstances ancient and current, by hydrological chronicles and archives documentation.

Community-level consequences of cannibalism.

PubMed

Ohlberger, Jan; Langangen, Oystein; Stenseth, Nils C; Vøllestad, L Asbjørn

2012-12-01

Ecological interactions determine the structure and dynamics of communities and their responses to the environment. Understanding the community-level effects of ecological interactions, such as intra- and interspecifc competition, predation, and cannibalism, is therefore central to ecological theory and ecosystem management. Here, we investigate the community-level consequences of cannibalism in populations with density-dependent maturation and reproduction. We model a stage-structured consumer population with an ontogenetic diet shift to analyze how cannibalism alters the conditions for the invasion and persistence of stage-specific predators and competitors. Our results demonstrate that cannibalistic interactions can facilitate coexistence with other species at both trophic levels. This effect of cannibalism critically depends on the food dependence of the demographic processes. The underlying mechanism is a cannibalism-induced shift in the biomass distribution between the consumer life stages. These findings suggest that cannibalism may alter the structure of ecological communities through its effects on species coexistence.

Simulating forest management and its effect on landscape pattern

Treesearch

Eric J. Gustafson

2017-01-01

Landscapes are characterized by their structure (the spatial arrangement of landscape elements), their ecological function (how ecological processes operate within that structure), and the dynamics of change (disturbance and recovery). Thus, understanding the dynamic nature of landscapes and predicting their future dynamics are of particular emphasis. Landscape change...

EFFECT OF SOIL PROPERTIES ON LEAD BIOAVAILABILITY AND TOXCITY TO EARTHWORMS

EPA Science Inventory

Soil properties are important factors modifying metal bioavailability to ecological receptors. Twenty-one soils with a wide range of soil properties were amended with a single concentration of Pb (2000 mg/kg) to determine the effects of soil properties on Pb bioavailability and ...

Urban Environments and Urban Children.

ERIC Educational Resources Information Center

Garbarino, James; Plantz, Margaret C.

This paper focuses on the distinctive characteristics of urban environments, the ways these environmental features affect city children, and the roles that schools can play in modifying these effects. Bronfenbrenner's multilevel framework for studying the ecology of human development is described. Recognizing the central role that families play in…

Young Children’s Developmental Ecologies and Kindergarten Readiness

PubMed Central

Mollborn, Stefanie

2016-01-01

Children enter the crucial transition to school with sociodemographic disparities firmly established. Domain-specific research (e.g., on poverty and family structure) has shed light on these disparities, but we need broader operationalizations of children’s environments to explain them. Building on existing theory, this study articulates the concept of developmental ecology—those interrelated features of a child’s proximal environment that shape development and health. Developmental ecology links structural and demographic factors with interactional, psychological, and genetic factors. Using the Early Childhood Longitudinal Study, Birth Cohort (ECLS-B), this study conducts latent class analyses to identify how 41 factors from three domains—namely, household resources, health risks, and ecological changes—cluster within children as four overarching developmental ecologies. Because it documents how numerous factors co-occur within children, this method allows an approximation of their lived environments. Findings illuminate powerful relationships between race/ethnicity, parental age, socioeconomic background, and nativity and a child’s developmental ecology, as well as associations between developmental ecology and kindergarten cognition, behavior, and health. Developmental ecology represents a major pathway through which demographic characteristics shape school readiness. Because specific factors have different implications depending on the ecologies in which they are embedded, findings support the usefulness of a broad ecological approach. PMID:27873222

Human Impacts and Climate Change Influence Nestedness and Modularity in Food-Web and Mutualistic Networks.

PubMed

Takemoto, Kazuhiro; Kajihara, Kosuke

2016-01-01

Theoretical studies have indicated that nestedness and modularity-non-random structural patterns of ecological networks-influence the stability of ecosystems against perturbations; as such, climate change and human activity, as well as other sources of environmental perturbations, affect the nestedness and modularity of ecological networks. However, the effects of climate change and human activities on ecological networks are poorly understood. Here, we used a spatial analysis approach to examine the effects of climate change and human activities on the structural patterns of food webs and mutualistic networks, and found that ecological network structure is globally affected by climate change and human impacts, in addition to current climate. In pollination networks, for instance, nestedness increased and modularity decreased in response to increased human impacts. Modularity in seed-dispersal networks decreased with temperature change (i.e., warming), whereas food web nestedness increased and modularity declined in response to global warming. Although our findings are preliminary owing to data-analysis limitations, they enhance our understanding of the effects of environmental change on ecological communities.

Urban reconciliation ecology: the potential of living roofs and walls.

PubMed

Francis, Robert A; Lorimer, Jamie

2011-06-01

Reconciling human and non-human use of urban regions to support biological conservation represents a major challenge for the 21st century. The concept of reconciliation ecology, by which the anthropogenic environment may be modified to encourage non-human use and biodiversity preservation without compromising societal utilization, potentially represents an appropriate paradigm for urban conservation given the generally poor opportunities that exist for reserve establishment and ecological restoration in urban areas. Two habitat improvement techniques with great potential for reconciliation ecology in urban areas are the installation of living roofs and walls, which have been shown to support a range of taxa at local scales. This paper evaluates the reconciliation potential of living roofs and walls, in particular highlighting both ecological and societal limitations that need to be overcome for application at the landscape scale. We further consider that successful utilization of living roofs and walls for urban reconciliation ecology will rely heavily on the participation of urban citizens, and that a 'citizen science' model is needed to facilitate public participation and support and to create an evidence base to determine their effectiveness. Living roofs and walls are just one aspect of urban reconciliation ecology, but are particularly important 'bottom-up' techniques for improving urban biodiversity that can be performed directly by the citizenry. Copyright © 2011 Elsevier Ltd. All rights reserved.

Hierarchical modeling and inference in ecology: The analysis of data from populations, metapopulations and communities

USGS Publications Warehouse

Royle, J. Andrew; Dorazio, Robert M.

2008-01-01

A guide to data collection, modeling and inference strategies for biological survey data using Bayesian and classical statistical methods. This book describes a general and flexible framework for modeling and inference in ecological systems based on hierarchical models, with a strict focus on the use of probability models and parametric inference. Hierarchical models represent a paradigm shift in the application of statistics to ecological inference problems because they combine explicit models of ecological system structure or dynamics with models of how ecological systems are observed. The principles of hierarchical modeling are developed and applied to problems in population, metapopulation, community, and metacommunity systems. The book provides the first synthetic treatment of many recent methodological advances in ecological modeling and unifies disparate methods and procedures. The authors apply principles of hierarchical modeling to ecological problems, including * occurrence or occupancy models for estimating species distribution * abundance models based on many sampling protocols, including distance sampling * capture-recapture models with individual effects * spatial capture-recapture models based on camera trapping and related methods * population and metapopulation dynamic models * models of biodiversity, community structure and dynamics.

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.

From bacteria to elephants: Effects of land-use legacies on biodiversity and ecosystem structure in the Serengeti-Mara ecosystem: Chapter 8

USGS Publications Warehouse

Verchot, Louis V.; Ward, Naomi L.; Belnap, Jayne; Bossio, Deborah; Coughenour, Michael; Gibson, John; Hanotte, Olivier; Muchiru, Andrew N.; Phillips, Susan L.; Steven, Blaire; Wall, Diana H.; Reid, Robin S.

2015-01-01

Generally, ecological research has considered the aboveground and belowground components of ecosystems separately. Consequently, frameworks for integrating the two components are not well developed. Integrating the microbial components into ecosystem ecology requires different approaches from those offered by plant ecology, partly because of the scales at which microbial processes operate and partly because of measurement constraints. Studies have begun to relate microbial community structure to ecosystem function. results suggest that excluding people and livestock from the MMNR, or preventing heavier livestock from grazing around settlements, may not change the general structure of the ecosystem (soils, plant structure), but can change the numbers and diversity of wildlife, nematodes and microbes in this ecosystem in subtle ways.

The role of geographical ecological studies in identifying diseases linked to UVB exposure and/or vitamin D

PubMed Central

Grant, William B.

2016-01-01

ABSTRACT Using a variety of approaches, researchers have studied the health effects of solar ultraviolet (UV) radiation exposure and vitamin D. This review compares the contributions from geographical ecological studies with those of observational studies and clinical trials. Health outcomes discussed were based on the author's knowledge and include anaphylaxis/food allergy, atopic dermatitis and eczema, attention deficit hyperactivity disorder, autism, back pain, cancer, dental caries, diabetes mellitus type 1, hypertension, inflammatory bowel disease, lupus, mononucleosis, multiple sclerosis, Parkinson disease, pneumonia, rheumatoid arthritis, and sepsis. Important interactions have taken place between study types; sometimes ecological studies were the first to report an inverse correlation between solar UVB doses and health outcomes such as for cancer, leading to both observational studies and clinical trials. In other cases, ecological studies added to the knowledge base. Many ecological studies include other important risk-modifying factors, thereby minimizing the chance of reporting the wrong link. Laboratory studies of mechanisms generally support the role of vitamin D in the outcomes discussed. Indications exist that for some outcomes, UVB effects may be independent of vitamin D. This paper discusses the concept of the ecological fallacy, noting that it applies to all epidemiological studies. PMID:27195055

[Ecological risk assessment of hydropower dam construction on aquatic species in middle reaches of Lancang River, Southwest China based on ESHIPPO model].

PubMed

Li, Xiao-Yan; Peng, Ming-Chun; Dong, Shi-Kui; Liu, Shi-Liang; Li, Jin-Peng; Yang, Zhi-Feng

2013-02-01

An investigation was conducted on the phytoplankton, zooplankton, and fish at 8 sampling sections in the Manwan Reservoir before and after the construction of Xiaowan Hydropower Dam. The modified ESHIPPO model was applied to study the changes of the featured aquatic species, including endangered species, endemic specie, peis resource species, and native fish, aimed to make an ecological risk assessment of the dam construction on the aquatic species. The dam construction had definite ecological risk on the aquatic species, especially the endemic fish, in Langcang River, due to the changes of hydrological conditions. The endemic species including Bangia atropurpurea, Lemanea sinica, Prasiola sp., Attheyella yunnanensis, and Neutrodiaptomus mariadvigae were at high ecological risk, and thus, besides monitoring, protection measures were needed to be taken to lower the possibility of the species extinction. The widely distributed species of phytoplankton and zooplankton were at medium ecological risk, and protection measures besides monitoring should be prepared. Twelve kinds of native fish, including Barbodes huangchuchieni, Sinilabeo laticeps, Racoma lantsangensis, Racoma lissolabiatus, Paracobitis anguillioides, Schistura latifasciata, Botia nigrolineata, Vanmanenia striata, Homaloptera yunnanensis, Platytropius longianlis, Glyptothorax zanaensis, and Pseudecheneis immaculate, were at high ecological risk, and protection measures needed to be developed to prevent the possibility of the species loss and extinction.

Ecological suicide in microbes.

PubMed

Ratzke, Christoph; Denk, Jonas; Gore, Jeff

2018-05-01

The growth and survival of organisms often depend on interactions between them. In many cases, these interactions are positive and caused by a cooperative modification of the environment. Examples are the cooperative breakdown of complex nutrients in microbes or the construction of elaborate architectures in social insects, in which the individual profits from the collective actions of her peers. However, organisms can similarly display negative interactions by changing the environment in ways that are detrimental for them, for example by resource depletion or the production of toxic byproducts. Here we find an extreme type of negative interactions, in which Paenibacillus sp. bacteria modify the environmental pH to such a degree that it leads to a rapid extinction of the whole population, a phenomenon that we call ecological suicide. Modification of the pH is more pronounced at higher population densities, and thus ecological suicide is more likely to occur with increasing bacterial density. Correspondingly, promoting bacterial growth can drive populations extinct whereas inhibiting bacterial growth by the addition of harmful substances-such as antibiotics-can rescue them. Moreover, ecological suicide can cause oscillatory dynamics, even in single-species populations. We found ecological suicide in a wide variety of microbes, suggesting that it could have an important role in microbial ecology and evolution.

Contact structure, mobility, environmental impact and behaviour: the importance of social forces to infectious disease dynamics and disease ecology

PubMed Central

Gurley, Emily S.

2017-01-01

Human factors, including contact structure, movement, impact on the environment and patterns of behaviour, can have significant influence on the emergence of novel infectious diseases and the transmission and amplification of established ones. As anthropogenic climate change alters natural systems and global economic forces drive land-use and land-cover change, it becomes increasingly important to understand both the ecological and social factors that impact infectious disease outcomes for human populations. While the field of disease ecology explicitly studies the ecological aspects of infectious disease transmission, the effects of the social context on zoonotic pathogen spillover and subsequent human-to-human transmission are comparatively neglected in the literature. The social sciences encompass a variety of disciplines and frameworks for understanding infectious diseases; however, here we focus on four primary areas of social systems that quantitatively and qualitatively contribute to infectious diseases as social–ecological systems. These areas are social mixing and structure, space and mobility, geography and environmental impact, and behaviour and behaviour change. Incorporation of these social factors requires empirical studies for parametrization, phenomena characterization and integrated theoretical modelling of social–ecological interactions. The social–ecological system that dictates infectious disease dynamics is a complex system rich in interacting variables with dynamically significant heterogeneous properties. Future discussions about infectious disease spillover and transmission in human populations need to address the social context that affects particular disease systems by identifying and measuring qualitatively important drivers. This article is part of the themed issue ‘Opening the black box: re-examining the ecology and evolution of parasite transmission’. PMID:28289265

Why are some plant-pollinator networks more nested than others?

PubMed

Song, Chuliang; Rohr, Rudolf P; Saavedra, Serguei

2017-10-01

Empirical studies have found that the mutualistic interactions forming the structure of plant-pollinator networks are typically more nested than expected by chance alone. Additionally, theoretical studies have shown a positive association between the nested structure of mutualistic networks and community persistence. Yet, it has been shown that some plant-pollinator networks may be more nested than others, raising the interesting question of which factors are responsible for such enhanced nested structure. It has been argued that ordered network structures may increase the persistence of ecological communities under less predictable environments. This suggests that nested structures of plant-pollinator networks could be more advantageous under highly seasonal environments. While several studies have investigated the link between nestedness and various environmental variables, unfortunately, there has been no unified answer to validate these predictions. Here, we move from the problem of describing network structures to the problem of comparing network structures. We develop comparative statistics, and apply them to investigate the association between the nested structure of 59 plant-pollinator networks and the temperature seasonality present in their locations. We demonstrate that higher levels of nestedness are associated with a higher temperature seasonality. We show that the previous lack of agreement came from an extended practice of using standardized measures of nestedness that cannot be compared across different networks. Importantly, our observations complement theory showing that more nested network structures can increase the range of environmental conditions compatible with species coexistence in mutualistic systems, also known as structural stability. This increase in nestedness should be more advantageous and occur more often in locations subject to random environmental perturbations, which could be driven by highly changing or seasonal environments. This synthesis of theory and observations could prove relevant for a better understanding of the ecological processes driving the assembly and persistence of ecological communities. © 2017 The Authors. Journal of Animal Ecology © 2017 British Ecological Society.

Social capital and common mental disorder: a systematic review.

PubMed

Ehsan, Annahita M; De Silva, Mary J

2015-10-01

This study aims to systematically review all published quantitative studies examining the direct association between social capital and common mental disorders (CMD). Social capital has potential value for the promotion and prevention of CMD. The association between different types of social capital (individual cognitive and structural, and ecological cognitive and structural) and CMD must be explored to obtain conclusive evidence regarding the association, and to ascertain a direction of causality. 10 electronic databases were searched to find studies examining the association between social capital and CMD published before July 2014. The effect estimates and sample sizes for each type of social capital were separately analysed for cross-sectional and cohort studies. From 1857 studies retrieved, 39 were selected for inclusion: 31 cross-sectional and 8 cohort studies. 39 effect estimates were found for individual level cognitive, 31 for individual level structural, 9 for ecological level cognitive and 11 for ecological level structural social capital. This review provides evidence that individual cognitive social capital is protective against developing CMD. Ecological cognitive social capital is also associated with reduced risk of CMD, though the included studies were cross-sectional. For structural social capital there was overall no association at either the individual or ecological levels. Two cross-sectional studies found that in low-income settings, a mother's participation in civic activities is associated with an increased risk of CMD. There is now sufficient evidence to design and evaluate individual and ecological cognitive social capital interventions to promote mental well-being and prevent CMD. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Structural landscape of base pairs containing post-transcriptional modifications in RNA

PubMed Central

Seelam, Preethi P.; Sharma, Purshotam

2017-01-01

Base pairs involving post-transcriptionally modified nucleobases are believed to play important roles in a wide variety of functional RNAs. Here we present our attempts toward understanding the structural and functional role of naturally occurring modified base pairs using a combination of X-ray crystal structure database analysis, sequence analysis, and advanced quantum chemical methods. Our bioinformatics analysis reveals that despite their presence in all major secondary structural elements, modified base pairs are most prevalent in tRNA crystal structures and most commonly involve guanine or uridine modifications. Further, analysis of tRNA sequences reveals additional examples of modified base pairs at structurally conserved tRNA regions and highlights the conservation patterns of these base pairs in three domains of life. Comparison of structures and binding energies of modified base pairs with their unmodified counterparts, using quantum chemical methods, allowed us to classify the base modifications in terms of the nature of their electronic structure effects on base-pairing. Analysis of specific structural contexts of modified base pairs in RNA crystal structures revealed several interesting scenarios, including those at the tRNA:rRNA interface, antibiotic-binding sites on the ribosome, and the three-way junctions within tRNA. These scenarios, when analyzed in the context of available experimental data, allowed us to correlate the occurrence and strength of modified base pairs with their specific functional roles. Overall, our study highlights the structural importance of modified base pairs in RNA and points toward the need for greater appreciation of the role of modified bases and their interactions, in the context of many biological processes involving RNA. PMID:28341704

River network architecture, genetic effective size and distributional patterns predict differences in genetic structure across species in a dryland stream fish community.

PubMed

Pilger, Tyler J; Gido, Keith B; Propst, David L; Whitney, James E; Turner, Thomas F

2017-05-01

Dendritic ecological network (DEN) architecture can be a strong predictor of spatial genetic patterns in theoretical and simulation studies. Yet, interspecific differences in dispersal capabilities and distribution within the network may equally affect species' genetic structuring. We characterized patterns of genetic variation from up to ten microsatellite loci for nine numerically dominant members of the upper Gila River fish community, New Mexico, USA. Using comparative landscape genetics, we evaluated the role of network architecture for structuring populations within species (pairwise F ST ) while explicitly accounting for intraspecific demographic influences on effective population size (N e ). Five species exhibited patterns of connectivity and/or genetic diversity gradients that were predicted by network structure. These species were generally considered to be small-bodied or habitat specialists. Spatial variation of N e was a strong predictor of pairwise F ST for two species, suggesting patterns of connectivity may also be influenced by genetic drift independent of network properties. Finally, two study species exhibited genetic patterns that were unexplained by network properties and appeared to be related to nonequilibrium processes. Properties of DENs shape community-wide genetic structure but effects are modified by intrinsic traits and nonequilibrium processes. Further theoretical development of the DEN framework should account for such cases. © 2017 John Wiley & Sons Ltd.

Changing perspectives on pearly mussels, North America's most imperiled animals

USGS Publications Warehouse

Strayer, David L.; Downing, John A.; Haag, Wendell R.; King, Timothy L.; Layzer, James B.; Newton, Teresa J.; Nichols, S. Jerrine

2004-01-01

Pearly mussels (Unionacea) are widespread, abundant, and important in freshwater ecosystems around the world. Catastrophic declines in pearly mussel populations in North America and other parts of the world have led to a flurry of research on mussel biology, ecology, and conservation. Recent research on mussel feeding, life history, spatial patterning, and declines has augmented, modified, or overturned long-held ideas about the ecology of these animals. Pearly mussel research has begun to benefit from and contribute to current ideas about suspension feeding, life-history theory, metapopulations, flow refuges, spatial patterning and its effects, and management of endangered species. At the same time, significant gaps in understanding and apparent paradoxes in pearly mussel ecology have been exposed. To conserve remaining mussel populations, scientists and managers must simultaneously and aggressively pursue both rigorous research and conservation actions.

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

Optimization of landscape pattern [Chapter 8

Treesearch

John Hof; Curtis Flather

2007-01-01

A fundamental assumption in landscape ecology is that spatial patterns have significant influences on the flows of materials, energy, and information while processes create, modify, and maintain spatial patterns. Thus, it is of paramount importance in both theory and practice to address the questions of landscape pattern optimization ... For example, can landscape...

Midlife and Midcareer Transitional Factors: Precursors of Successful Aging.

ERIC Educational Resources Information Center

Boylan, Richard J.; Hawkes, Glenn R.

Past research has examined middle adulthood as a developmental process with outcomes predictive of development into old age. A study was undertaken to explore adult psychological and career development from an ecological perspective taking into account factors that influence and modify self-perception, values, identity, and social interaction. A…

Edge Effects in Line Intersect Sampling With

Treesearch

David L. R. Affleck; Timothy G. Gregoire; Harry T. Valentine

2005-01-01

Transects consisting of multiple, connected segments with a prescribed configuration are commonly used in ecological applications of line intersect sampling. The transect configuration has implications for the probability with which population elements are selected and for how the selection probabilities can be modified by the boundary of the tract being sampled. As...

The Role of Ecology in Public Health: Research and Educational Opportunities Using EnviroAtlas

EPA Science Inventory

A growing area of public-health research and practice concerns the relationships between physical and visual access to urban green space, and stress, physical fitness, cognitive function and other aspects of health and wellness. Natural features can modify adverse effects of nois...

Climate change and Epichloë coenophiala association modify belowground fungal symbioses of tall fescue host

USDA-ARS?s Scientific Manuscript database

Human alteration of symbiont genetics among aboveground endophytic Epichloë coenophiala strains within tall fescue (Schedonorus arundinaceus) has led to widespread deployment of novel grass-endophyte combinations, yet little is known about their ecological consequences. In this study, clone pairs (e...

76 FR 34967 - Endangered Species; File No. 10027

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-15

...-226). The permit currently authorizes the permit holder to study the population biology and... distribution and abundance, ecology, health, and threats to sea turtles at the Palmyra Atoll in the Pacific... the population of sea turtles at Palmyra. The modified permit would expire July 31, 2013. Dated: June...

Landsliding and its multiscale influence on mountainscapes

Treesearch

Carla Restrepo; Lawrence R. Walker; Aaron B. Shiels; Rainer Bussmann; Lieven Claessens; Simey Fisch; Pablo Lozano; Girish Negi; Leonardo Paolini; Germán Poveda; Carlos Ramos-Sharrón; Michael Ritcher; Eduardo Velázquez

2009-01-01

Landsliding is a complex process that modifies mountainscapes worldwide. Its severe and sometimes long-lasting negative effects contrast with the less-documented positive effects on ecosystems, raising numerous questions about the dual role of landsliding, the feedbacks between biotic and geomorphic processes, and, ultimately, the ecological and evolutionary responses...

Glyphosate drift promotes changes in fitness and transgene flow in canola (Brassica napus) and hybrids

EPA Science Inventory

1. With the advent of transgenic crops, genetically modified, herbicide resistant B. napus has become a model system for examining the risks of escape of transgenes from cultivation and for evaluating potential ecological consequences of novel genes in wild species. 2. We exam...

Handbook for Ecology Action.

ERIC Educational Resources Information Center

Eber, Ronald

This handbook has been compiled to aid concerned individuals and ecology groups more adequately define their goals, initiate good programs, and take effective action. It examines the ways a group of working individuals can become involved in action programs for ecological change. Part 1 deals with organization, preliminary organizing, structuring,…

Glycomics: revealing the dynamic ecology and evolution of sugar molecules.

PubMed

Springer, Stevan A; Gagneux, Pascal

2016-03-01

Sugars are the most functionally and structurally diverse molecules in the biological world. Glycan structures range from tiny single monosaccharide units to giant chains thousands of units long. Some glycans are branched, their monosaccharides linked together in many different combinations and orientations. Some exist as solitary molecules; others are conjugated to proteins and lipids and alter their collective functional properties. In addition to structural and storage roles, glycan molecules participate in and actively regulate physiological and developmental processes. Glycans also mediate cellular interactions within and between individuals. Their roles in ecology and evolution are pivotal, but not well studied because glycan biochemistry requires different methods than standard molecular biology practice. The properties of glycans are in some ways convenient, and in others challenging. Glycans vary on organismal timescales, and in direct response to physiological and ecological conditions. Their mature structures are physical records of both genetic and environmental influences during maturation. We describe the scope of natural glycan variation and discuss how studying glycans will allow researchers to further integrate the fields of ecology and evolution. Copyright © 2015 Elsevier B.V. All rights reserved.

Comparative use of side and main channels by small-bodied fish in a large, unimpounded river

USGS Publications Warehouse

Reinhold, Ann Marie; Bramblett, Robert G.; Zale, Alexander V.; Roberts, David W.; Poole, Geoffrey C.

2016-01-01

Ecological theory and field studies suggest that lateral floodplain connectivity and habitat heterogeneity provided by side channels impart favourable habitat conditions for lotic fishes, especially fluvial fishes dependent on large patches of shallow, slow velocity habitats for some portion of their life cycle. However, anthropogenic modification of large, temperate floodplain rivers has led to extensive channel simplification and side-channel loss. Highly modified rivers consist of simplified channels in contracted, less dynamic floodplains.Most research examining the seasonal importance of side channels for fish assemblages in large rivers has been carried out in heavily modified rivers, where side-channel extents are substantially reduced from pre-settlement times, and has often overlooked small-bodied fishes. Inferences about the ecological importance of side channels for small-bodied fishes in large rivers can be ascertained only from investigations of large rivers with largely intact floodplains. The Yellowstone River, our study area, is a rare example of one such river.We targeted small-bodied fishes and compared their habitat use in side and main channels in two geomorphically distinct types of river bends during early and late snowmelt runoff, and autumn base flow. Species compositions of side and main channels differed throughout hydroperiods concurrent with the seasonal redistribution of the availability of shallow, slow current-velocity habitats. More species of fish used side channels than main channels during runoff. Additionally, catch rates of small fishes were generally greater in side channels than in main channels and quantitative assemblage compositions differed between channel types during runoff, but not during base flow. Presence of and access to diverse habitats facilitated the development and persistence of diverse fish assemblages in our study area.Physical dissimilarities between side and main channels may have differentially structured the side- and main-channel fish assemblages during runoff. Patches of shallow, slow current-velocity (SSCV) habitats in side channels were larger and had slightly slower water velocities than SSCV habitat patches in main channels during runoff, but not during base flow.Our findings establish a baseline importance of side channels to riverine fishes in a large, temperate river without heavy anthropogenic modification. Establishing this baseline contributes to basic fluvial ecology and provides empirical justification for restoration efforts that reconnect large rivers with their floodplains.

Swashed away? Storm impacts on sandy beach macrofaunal communities

NASA Astrophysics Data System (ADS)

Harris, Linda; Nel, Ronel; Smale, Malcolm; Schoeman, David

2011-09-01

Storms can have a large impact on sandy shores, with powerful waves eroding large volumes of sand off the beach. Resulting damage to the physical environment has been well-studied but the ecological implications of these natural phenomena are less known. Since climate change predictions suggest an increase in storminess in the near future, understanding these ecological implications is vital if sandy shores are to be proactively managed for resilience. Here, we report on an opportunistic experiment that tests the a priori expectation that storms impact beach macrofaunal communities by modifying natural patterns of beach morphodynamics. Two sites at Sardinia Bay, South Africa, were sampled for macrofauna and physical descriptors following standard sampling methods. This sampling took place five times at three- to four-month intervals between April 2008 and August 2009. The second and last sampling events were undertaken after unusually large storms, the first of which was sufficiently large to transform one site from a sandy beach into a mixed shore for the first time in living memory. A range of univariate (linear mixed-effects models) and multivariate (e.g. non-metric multidimensional scaling, PERMANOVA) methods were employed to describe trends in the time series, and to explore the likelihood of possible explanatory mechanisms. Macrofaunal communities at the dune-backed beach (Site 2) withstood the effects of the first storm but were altered significantly by the second storm. In contrast, macrofauna communities at Site 1, where the supralittoral had been anthropogenically modified so that exchange of sediments with the beach was limited, were strongly affected by the first storm and showed little recovery over the study period. In line with predictions from ecological theory, beach morphodynamics was found to be a strong driver of temporal patterns in the macrofaunal community structure, with the storm events also identified as a significant factor, likely because of their direct effects on beach morphodynamics. Our results also support those of other studies suggesting that developed shores are more impacted by storms than are undeveloped shores. Whilst recognising we cannot generalise too far beyond our limited study, our results contribute to the growing body of evidence that interactions between sea-level rise, increasing storminess and the expansion of anthropogenic modifications to the shoreline will place functional beach ecosystems under severe pressure over the forthcoming decades and we therefore encourage further, formal testing of these concepts.

Interactions between Genetic and Ecological Effects on the Evolution of Life Cycles.

PubMed

Rescan, Marie; Lenormand, Thomas; Roze, Denis

2016-01-01

Sexual reproduction leads to an alternation between haploid and diploid phases, whose relative length varies widely across taxa. Previous genetical models showed that diploid or haploid life cycles may be favored, depending on dominance interactions and on effective recombination rates. By contrast, niche differentiation between haploids and diploids may favor biphasic life cycles, in which development occurs in both phases. In this article, we explore the interplay between genetical and ecological factors, assuming that deleterious mutations affect the competitivity of individuals within their ecological niche and allowing different effects of mutations in haploids and diploids (including antagonistic selection). We show that selection on a modifier gene affecting the relative length of both phases can be decomposed into a direct selection term favoring the phase with the highest mean fitness (due to either ecological differences or differential effects of mutations) and an indirect selection term favoring the phase in which selection is more efficient. When deleterious alleles occur at many loci and in the presence of ecological differentiation between haploids and diploids, evolutionary branching often occurs and leads to the stable coexistence of alleles coding for haploid and diploid cycles, while temporal variations in niche sizes may stabilize biphasic cycles.

Individuals and populations: the role of long-term, individual-based studies of animals in ecology and evolutionary biology.

PubMed

Clutton-Brock, Tim; Sheldon, Ben C

2010-10-01

Many important questions in ecology and evolutionary biology can only be answered with data that extend over several decades and answering a substantial proportion of questions requires records of the life histories of recognisable individuals. We identify six advantages that long-term, individual based studies afford in ecology and evolution: (i) analysis of age structure; (ii) linkage between life history stages; (iii) quantification of social structure; (iv) derivation of lifetime fitness measures; (v) replication of estimates of selection; (vi) linkage between generations, and we review their impact on studies in six key areas of evolution and ecology. Our review emphasises the unusual opportunities and productivity of long-term, individual-based studies and documents the important role that they play in research on ecology and evolutionary biology as well as the difficulties they face. Copyright © 2010 Elsevier Ltd. All rights reserved.

Adaptation and validation of the Tower of London test of planning and problem solving in people with intellectual disabilities.

PubMed

Masson, J D; Dagnan, D; Evans, J

2010-05-01

There is a need for validated, standardised tools for the assessment of executive functions in adults with intellectual disabilities (ID). This study examines the validity of a test of planning and problem solving (Tower of London) with adults with ID. Participants completed an adapted version of the Tower of London (ToL) while day-centre staff completed adaptive function (Adaptive Behaviour Scale - Residential and Community: Second Edition, modified version) and dysexecutive function (DEX-Independent Rater) questionnaires for each participant. Correlation analyses of test and questionnaire variables were undertaken. The adapted ToL has a robust structure and shows significant associations with independent living skills, challenging behaviour and behaviours related to dysexecutive function. The adapted ToL is a valid test for use with people with ID. However, there is also a need to develop other ecologically valid tools based on everyday planning tasks undertaken by people with ID.

Sporulation in the Budding Yeast Saccharomyces cerevisiae

PubMed Central

Neiman, Aaron M.

2011-01-01

In response to nitrogen starvation in the presence of a poor carbon source, diploid cells of the yeast Saccharomyces cerevisiae undergo meiosis and package the haploid nuclei produced in meiosis into spores. The formation of spores requires an unusual cell division event in which daughter cells are formed within the cytoplasm of the mother cell. This process involves the de novo generation of two different cellular structures: novel membrane compartments within the cell cytoplasm that give rise to the spore plasma membrane and an extensive spore wall that protects the spore from environmental insults. This article summarizes what is known about the molecular mechanisms controlling spore assembly with particular attention to how constitutive cellular functions are modified to create novel behaviors during this developmental process. Key regulatory points on the sporulation pathway are also discussed as well as the possible role of sporulation in the natural ecology of S. cerevisiae. PMID:22084423

Coupling movement and landscape ecology for animal conservation in production landscapes.

PubMed

Doherty, Tim S; Driscoll, Don A

2018-01-10

Habitat conversion in production landscapes is among the greatest threats to biodiversity, not least because it can disrupt animal movement. Using the movement ecology framework, we review animal movement in production landscapes, including areas managed for agriculture and forestry. We consider internal and external drivers of altered animal movement and how this affects navigation and motion capacities and population dynamics. Conventional management approaches in fragmented landscapes focus on promoting connectivity using structural changes in the landscape. However, a movement ecology perspective emphasizes that manipulating the internal motivations or navigation capacity of animals represents untapped opportunities to improve movement and the effectiveness of structural connectivity investments. Integrating movement and landscape ecology opens new opportunities for conservation management in production landscapes. © 2018 The Authors.

[Ecological memory and its potential applications in ecology: a review].

PubMed

Sun, Zhong-yu; Ren, Hai

2011-03-01

Ecological memory (EM) is defined as the capability of the past states or experiences of a community to influence the present or future ecological responses of the community. As a relatively new concept, EM has received considerable attention in the study of ecosystem structure and function, such as community succession, ecological restoration, biological invasion, and natural resource management. This review summarized the definition, components, and categories of EM, and discussed the possible mechanisms and affecting factors of EM. Also, the potential applications of EM were proposed, in order to further understand the mechanisms of community succession and to guide ecological restoration.

[A process of aquatic ecological function regionalization: The dual tree framework and conceptual model].

PubMed

Guo, Shu Hai; Wu, Bo

2017-12-01

Aquatic ecological regionalization and aquatic ecological function regionalization are the basis of water environmental management of a river basin and rational utilization of an aquatic ecosystem, and have been studied in China for more than ten years. Regarding the common problems in this field, the relationship between aquatic ecological regionalization and aquatic ecological function regionalization was discussed in this study by systematic analysis of the aquatic ecological zoning and the types of aquatic ecological function. Based on the dual tree structure, we put forward the RFCH process and the diamond conceptual model. Taking Liaohe River basin as an example and referring to the results of existing regionalization studies, we classified the aquatic ecological function regions based on three-class aquatic ecological regionalization. This study provided a process framework for aquatic ecological function regionalization of a river basin.

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*}]).

Modelling non-Euclidean movement and landscape connectivity in highly structured ecological networks

USGS Publications Warehouse

Sutherland, Christopher; Fuller, Angela K.; Royle, J. Andrew

2015-01-01

The ecological distance SCR model uses spatially indexed capture-recapture data to estimate how activity patterns are influenced by landscape structure. As well as reducing bias in estimates of abundance, this approach provides biologically realistic representations of home range geometry, and direct information about species-landscape interactions. The incorporation of both structural (landscape) and functional (movement) components of connectivity provides a direct measure of species-specific landscape connectivity.

Workshop on Closed System Ecology

NASA Technical Reports Server (NTRS)

1982-01-01

Self maintaining laboratory scale ecological systems completely isolated from exchanges of matter with external systems were demonstrated. These research tools are discussed in terms of their anticipated value in understanding (1) global ecological material and energy balances, (2) the dynamics of stability and instability in ecosystems, (3) the effects of man-made substances and structures on ecosystems, and (4) the precise requirements for dynamic control of controlled ecology life support systems (CELSS).

Identifying socio-ecological networks in rural-urban gradients: Diagnosis of a changing cultural landscape.

PubMed

Arnaiz-Schmitz, C; Schmitz, M F; Herrero-Jáuregui, C; Gutiérrez-Angonese, J; Pineda, F D; Montes, C

2018-01-15

Socio-ecological systems maintain reciprocal interactions between biophysical and socioeconomic structures. As a result of these interactions key essential services for society emerge. Urban expansion is a direct driver of land change and cause serious shifts in socio-ecological relationships and the associated lifestyles. The framework of rural-urban gradients has proved to be a powerful tool for ecological research about urban influences on ecosystems and on sociological issues related to social welfare. However, to date there has not been an attempt to achieve a classification of municipalities in rural-urban gradients based on socio-ecological interactions. In this paper, we developed a methodological approach that allows identifying and classifying a set of socio-ecological network configurations in the Region of Madrid, a highly dynamic cultural landscape considered one of the European hotspots in urban development. According to their socio-ecological links, the integrated model detects four groups of municipalities, ordered along a rural-urban gradient, characterized by their degree of biophysical and socioeconomic coupling and different indicators of landscape structure and social welfare. We propose the developed model as a useful tool to improve environmental management schemes and land planning from a socio-ecological perspective, especially in territories subject to intense urban transformations and loss of rurality. Copyright © 2017 Elsevier B.V. All rights reserved.

Justice Is the Missing Link in One Health: Results of a Mixed Methods Study in an Urban City State

PubMed Central

Capps, Benjamin; Bailey, Michele; Bickford, David; Coker, Richard; Lederman, Zohar; Watson, Sangeetha; Tambyah, Paul Anantharajah

2017-01-01

Background One Health (OH) is an interdisciplinary collaborative approach to human and animal health that aims to break down conventional research and policy ‘silos’. OH has been used to develop strategies for zoonotic Emerging Infectious Diseases (EID). However, the ethical case for OH as an alternative to more traditional public health approaches is largely absent from the discourse. To study the ethics of OH, we examined perceptions of the human health and ecological priorities for the management of zoonotic EID in the Southeast Asia country of Singapore. Methods We conducted a mixed methods study using a modified Delphi technique with a panel of 32 opinion leaders and 11 semi-structured interviews with a sub-set of those experts in Singapore. Panellists rated concepts of OH and priorities for zoonotic EID preparedness planning using a series of scenarios developed through the study. Interview data were examined qualitatively using thematic analysis. Findings We found that panellists agreed that OH is a cross-disciplinary collaboration among the veterinary, medical, and ecological sciences, as well as relevant government agencies encompassing animal, human, and environmental health. Although human health was often framed as the most important priority in zoonotic EID planning, our qualitative analysis suggested that consideration of non-human animal health and welfare was also important for an effective and ethical response. The panellists also suggested that effective pandemic planning demands regional leadership and investment from wealthier countries to better enable international cooperation. Conclusion We argue that EID planning under an OH approach would benefit greatly from an ethical ecological framework that accounts for justice in human, animal, and environmental health. PMID:28129409

Keystone predators (eastern newts, Notophthalmus viridescens) reduce the impacts of an aquatic invasive species

USGS Publications Warehouse

Smith, Kimberly G.

2006-01-01

Predation, competition, and their interaction are known to be important factors that influence the structure of ecological communities. In particular, in those cases where a competitive hierarchy exists among prey species, the presence of certain keystone predators can result in enhanced diversity in the prey community. However, little is known regarding the influence of keystone predator presence on invaded prey communities. Given the widespread occurrence of invasive species and substantial concern regarding their ecological impacts, studies on this topic are needed. In this study I used naturalistic replications of an experimental tadpole assemblage to assess the influence of predatory eastern newts, Notophthalmus viridescens, on the outcome of interspecific competition among native and nonindigenous tadpoles. When newts were absent, the presence of the tadpoles of one invasive species, the Cuban treefrog, Osteopilus septentrionalis, resulted in decreased survival and growth rate of the dominant native species, Bufo terrestris, and dominance of the tadpole assemblage by O. septentrionalis. However, the presence of one adult newt generally reduced or eliminated the negative impacts of O. septentrionalis tadpoles, resulting in comparable survival and performance of native species in invaded and noninvaded treatments. Differential mortality among the tadpole species suggests that newts preyed selectively on O. septentrionalis tadpoles, supporting the hypothesis that newts acted as keystone predators in the invaded assemblage. The presence of nonindigenous larval cane toads, Bufo marinus, did not significantly affect native species, and this species was not negatively affected by the presence of newts. Collectively, these results suggest that eastern newts significantly modified the competitive hierarchy of the invaded tadpole assemblage and reduced the impacts of a competitively superior invasive species. If general, these results suggest that the presence of certain species may be an essential factor regulating the ecological impacts of biological invasions.

Burrow characteristics of the mud shrimp Austinogebia edulis, an ecological engineer causing sediment modification of a tidal flat.

PubMed

Das, Shagnika; Tseng, Li-Chun; Wang, Lan; Hwang, Jiang-Shiou

2017-01-01

The mud shrimp Austinogebia edulis, being abundant in the intertidal zone of western Taiwan, constructs deep burrows (>1 m). This study highlights the potential of mud shrimps to modify sediment characteristics of the tidal flat by its burrowing behavior. We studied the structure of the burrow wall, compared the difference in the sediment composition of the burrow and the background sediment, and compared the organic content inside the burrow wall. This study was carried out from September 2015 to November 2016 in three areas of the western coast of Taiwan, namely Shengang, Hanbow, and Wangong. The present study found significant differences between burrow wall and the burrow lumen. The diameter of the burrow wall was double as wide as the inner burrow lumen at the opening and gradually increased to 10 times of the burrow lumen at 30 cm depth. The burrow wall of A. edulis showed low permeability and increased the sheer strength. Statistically, a significant difference was noticed in the comparison between the sediment composition of the burrow wall and the background (p < 0.05, Student's t-test). An accumulation of 3.63 for fine sand (t = -5.22, p < 0.001, fine sand) and 9 for clay (t = -25.01, p < 0.001, clay) was found in the upper burrow wall of A. edulis. This indicated that they somehow chose finer particles to build burrows. This will gradually change the sediment distribution-vertically and horizontally. The burrow wall consisted of a 24 times higher organic matter content than one individual of mud shrimp. The burrow may provide organic material as a potential food source. The mud shrimp thus transforms the sediment characteristics as an ecological engineer, which is expected to have a significant ecological impact on the ecosystem.

Justice Is the Missing Link in One Health: Results of a Mixed Methods Study in an Urban City State.

PubMed

Lysaght, Tamra; Capps, Benjamin; Bailey, Michele; Bickford, David; Coker, Richard; Lederman, Zohar; Watson, Sangeetha; Tambyah, Paul Anantharajah

2017-01-01

One Health (OH) is an interdisciplinary collaborative approach to human and animal health that aims to break down conventional research and policy 'silos'. OH has been used to develop strategies for zoonotic Emerging Infectious Diseases (EID). However, the ethical case for OH as an alternative to more traditional public health approaches is largely absent from the discourse. To study the ethics of OH, we examined perceptions of the human health and ecological priorities for the management of zoonotic EID in the Southeast Asia country of Singapore. We conducted a mixed methods study using a modified Delphi technique with a panel of 32 opinion leaders and 11 semi-structured interviews with a sub-set of those experts in Singapore. Panellists rated concepts of OH and priorities for zoonotic EID preparedness planning using a series of scenarios developed through the study. Interview data were examined qualitatively using thematic analysis. We found that panellists agreed that OH is a cross-disciplinary collaboration among the veterinary, medical, and ecological sciences, as well as relevant government agencies encompassing animal, human, and environmental health. Although human health was often framed as the most important priority in zoonotic EID planning, our qualitative analysis suggested that consideration of non-human animal health and welfare was also important for an effective and ethical response. The panellists also suggested that effective pandemic planning demands regional leadership and investment from wealthier countries to better enable international cooperation. We argue that EID planning under an OH approach would benefit greatly from an ethical ecological framework that accounts for justice in human, animal, and environmental health.

The ecological impacts of nighttime light pollution: a mechanistic appraisal.

PubMed

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

2013-11-01

The ecological impacts of nighttime light pollution have been a longstanding source of concern, accentuated by realized and projected growth in electrical lighting. As human communities and lighting technologies develop, artificial light increasingly modifies natural light regimes by encroaching on dark refuges in space, in time, and across wavelengths. A wide variety of ecological implications of artificial light have been identified. However, the primary research to date is largely focused on the disruptive influence of nighttime light on higher vertebrates, and while comprehensive reviews have been compiled along taxonomic lines and within specific research domains, the subject is in need of synthesis within a common mechanistic framework. Here we propose such a framework that focuses on the cross-factoring of the ways in which artificial lighting alters natural light regimes (spatially, temporally, and spectrally), and the ways in which light influences biological systems, particularly the distinction between light as a resource and light as an information source. We review the evidence for each of the combinations of this cross-factoring. As artificial lighting alters natural patterns of light in space, time and across wavelengths, natural patterns of resource use and information flows may be disrupted, with downstream effects to the structure and function of ecosystems. This review highlights: (i) the potential influence of nighttime lighting at all levels of biological organisation (from cell to ecosystem); (ii) the significant impact that even low levels of nighttime light pollution can have; and (iii) the existence of major research gaps, particularly in terms of the impacts of light at population and ecosystem levels, identification of intensity thresholds, and the spatial extent of impacts in the vicinity of artificial lights. © 2013 The Authors. Biological Reviews © 2013 Cambridge Philosophical Society.

Objective classification of ecological status in marine water bodies using ecotoxicological information and multivariate analysis.

PubMed

Beiras, Ricardo; Durán, Iria

2014-12-01

Some relevant shortcomings have been identified in the current approach for the classification of ecological status in marine water bodies, leading to delays in the fulfillment of the Water Framework Directive objectives. Natural variability makes difficult to settle fixed reference values and boundary values for the Ecological Quality Ratios (EQR) for the biological quality elements. Biological responses to environmental degradation are frequently of nonmonotonic nature, hampering the EQR approach. Community structure traits respond only once ecological damage has already been done and do not provide early warning signals. An alternative methodology for the classification of ecological status integrating chemical measurements, ecotoxicological bioassays and community structure traits (species richness and diversity), and using multivariate analyses (multidimensional scaling and cluster analysis), is proposed. This approach does not depend on the arbitrary definition of fixed reference values and EQR boundary values, and it is suitable to integrate nonlinear, sensitive signals of ecological degradation. As a disadvantage, this approach demands the inclusion of sampling sites representing the full range of ecological status in each monitoring campaign. National or international agencies in charge of coastal pollution monitoring have comprehensive data sets available to overcome this limitation.

Contact structure, mobility, environmental impact and behaviour: the importance of social forces to infectious disease dynamics and disease ecology.

PubMed

Arthur, Ronan F; Gurley, Emily S; Salje, Henrik; Bloomfield, Laura S P; Jones, James H

2017-05-05

Human factors, including contact structure, movement, impact on the environment and patterns of behaviour, can have significant influence on the emergence of novel infectious diseases and the transmission and amplification of established ones. As anthropogenic climate change alters natural systems and global economic forces drive land-use and land-cover change, it becomes increasingly important to understand both the ecological and social factors that impact infectious disease outcomes for human populations. While the field of disease ecology explicitly studies the ecological aspects of infectious disease transmission, the effects of the social context on zoonotic pathogen spillover and subsequent human-to-human transmission are comparatively neglected in the literature. The social sciences encompass a variety of disciplines and frameworks for understanding infectious diseases; however, here we focus on four primary areas of social systems that quantitatively and qualitatively contribute to infectious diseases as social-ecological systems. These areas are social mixing and structure, space and mobility, geography and environmental impact, and behaviour and behaviour change. Incorporation of these social factors requires empirical studies for parametrization, phenomena characterization and integrated theoretical modelling of social-ecological interactions. The social-ecological system that dictates infectious disease dynamics is a complex system rich in interacting variables with dynamically significant heterogeneous properties. Future discussions about infectious disease spillover and transmission in human populations need to address the social context that affects particular disease systems by identifying and measuring qualitatively important drivers.This article is part of the themed issue 'Opening the black box: re-examining the ecology and evolution of parasite transmission'. © 2017 The Author(s).

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.

Ecological Network Analysis for a Low-Carbon and High-Tech Industrial Park

PubMed Central

Lu, Yi; Su, Meirong; Liu, Gengyuan; Chen, Bin; Zhou, Shiyi; Jiang, Meiming

2012-01-01

Industrial sector is one of the indispensable contributors in global warming. Even if the occurrence of ecoindustrial parks (EIPs) seems to be a good improvement in saving ecological crises, there is still a lack of definitional clarity and in-depth researches on low-carbon industrial parks. In order to reveal the processes of carbon metabolism in a low-carbon high-tech industrial park, we selected Beijing Development Area (BDA) International Business Park in Beijing, China as case study, establishing a seven-compartment- model low-carbon metabolic network based on the methodology of Ecological Network Analysis (ENA). Integrating the Network Utility Analysis (NUA), Network Control Analysis (NCA), and system-wide indicators, we compartmentalized system sectors into ecological structure and analyzed dependence and control degree based on carbon metabolism. The results suggest that indirect flows reveal more mutuality and exploitation relation between system compartments and they are prone to positive sides for the stability of the whole system. The ecological structure develops well as an approximate pyramidal structure, and the carbon metabolism of BDA proves self-mutualistic and sustainable. Construction and waste management were found to be two active sectors impacting carbon metabolism, which was mainly regulated by internal and external environment. PMID:23365516

Landscape genetic connectivity in a riparian foundation tree is jointly driven by climatic gradients and river networks

Treesearch

Samuel A. Cushman; Tamara Max; Nashelly Meneses; Luke M. Evans; Sharon Ferrier; Barbara Honchak; Thomas G. Whitham; Gerard J. Allan

2014-01-01

Fremont cottonwood (Populus fremonti) is a foundation riparian tree species that drives community structure and ecosystem processes in southwestern U.S. ecosystems. Despite its ecological importance, little is known about the ecological and environmental processes that shape its genetic diversity, structure, and landscape connectivity. Here, we combined...

Influence of forest structure and experimental green-tree retention on northern flying squirrel (Glaucomys sabrinus) abundance

Treesearch

Gillian L. Holloway; Winston P. Smith; Charles B. Halpern; Robert A. Gitzen; Christine C. Maguire; Stephen D. West

2012-01-01

In many regions of the world, forest management has shifted from practices emphasizing timber production to more sustainable harvesting that integrates ecological values, including maintenance of biodiversity, wildlife habitat, and ecological goods and services. To this end, management strategies emphasize retention of stand structures that meet the needs of forest-...

Insights on Forest Structure and Composition from Long-Term Research in the Luquillo Mountains

Treesearch

Tamara Heartsill Scalley

2017-01-01

The science of ecology fundamentally aims to understand species and their relation to the environment. At sites where hurricane disturbance is part of the environmental context, permanent forest plots are critical to understand ecological vegetation dynamics through time. An overview of forest structure and species composition from two of the longest continuously...

Ecological resource management: A call to arms

USGS Publications Warehouse

Emlen, J.M.; Kapustka, Lawrence; Barnthouse, L.; Beyer, N.; Biddinger, G.; Kedwards, T.; Landis, W.; Menzie, C.; Munns, W.; Sorenson, M.; Wentsel, R.

2002-01-01

As the human population enlarges, it becomes increasingly difficult to sustain valued ecological resources. Human use of resources, whether it is the harvest of ocean fisheries, logging of forests, or farming of arable lands, has resulted in significant population declines in many wildlife species. The growth of urban areas and the expansion of impermeable surfaces alter landscape diversity and modify hydrologic patterns in ways that decrease habitat quality for many desired plant, fish, and wildlife species. Impaired water, air, and soil quality related to industrial, municipal, and agricultural activities have altered the composition of aquatic and terrestrial communities.

The Relationship between Cranial Structure, Biomechanical Performance and Ecological Diversity in Varanoid Lizards

PubMed Central

McCurry, Matthew R.; Mahony, Michael; Clausen, Phillip D.; Quayle, Michelle R.; Walmsley, Christopher W.; Jessop, Tim S.; Wroe, Stephen; Richards, Heather; McHenry, Colin R.

2015-01-01

Skull structure is intimately associated with feeding ability in vertebrates, both in terms of specific performance measures and general ecological characteristics. This study quantitatively assessed variation in the shape of the cranium and mandible in varanoid lizards, and its relationship to structural performance (von Mises strain) and interspecific differences in feeding ecology. Geometric morphometric and linear morphometric analyses were used to evaluate morphological differences, and finite element analysis was used to quantify variation in structural performance (strain during simulated biting, shaking and pulling). This data was then integrated with ecological classes compiled from relevant scientific literature on each species in order to establish structure-function relationships. Finite element modelling results showed that variation in cranial morphology resulted in large differences in the magnitudes and locations of strain in biting, shaking and pulling load cases. Gracile species such as Varanus salvadorii displayed high strain levels during shaking, especially in the areas between the orbits. All models exhibit less strain during pull back loading compared to shake loading, even though a larger force was applied (pull =30N, shake = 20N). Relationships were identified between the morphology, performance, and ecology. Species that did not feed on hard prey clustered in the gracile region of cranial morphospace and exhibited significantly higher levels of strain during biting (P = 0.0106). Species that fed on large prey clustered in the elongate area of mandible morphospace. This relationship differs from those that have been identified in other taxonomic groups such as crocodiles and mammals. This difference may be due to a combination of the open ‘space-frame’ structure of the varanoid lizard skull, and the ‘pull back’ behaviour that some species use for processing large prey. PMID:26106889

Incorporating ecogeomorphic feedbacks to better understand resiliency in streams: A review and directions forward

NASA Astrophysics Data System (ADS)

Atkinson, Carla L.; Allen, Daniel C.; Davis, Lisa; Nickerson, Zachary L.

2018-03-01

Decades of interdisciplinary research show river form and function depends on interactions between the living and nonliving world, but a dominant paradigm underlying ecogeomorphic work consists of a top-down, unidirectional approach with abiotic forces driving biotic systems. Stream form and location within the stream network does dictate the habitat and resources available for organisms and overall community structure. Yet this traditional hierarchal framework on its own is inadequate in communicating information regarding the influence of biological systems on fluvial geomorphology that lead to changes in channel morphology, sediment cycling, and system-scale functions (e.g., sediment yield, biogeochemical nutrient cycling). Substantial evidence that organisms influence fluvial geomorphology exists, specifically the ability of aquatic vegetation and lotic animals to modify flow velocities and sediment deposition and transport - thus challenging the traditional hierarchal framework. Researchers recognize the need for ecogeomorphic frameworks that conceptualize feedbacks between organisms, sediment transport, and geomorphic structure. Furthermore, vital ecosystem processes, such as biogeochemical nutrient cycling represent the conversations that are occurring between geomorphological and biological systems. Here we review and synthesize selected case studies highlighting the role organisms play in moderating geomorphic processes and likely interact with these processes to have an impact on an essential ecosystem process, biogeochemical nutrient recycling. We explore whether biophysical interactions can provide information essential to improving predictions of system-scale river functions, specifically sediment transport and biogeochemical cycling, and discuss tools used to study these interactions. We suggest that current conceptual frameworks should acknowledge that hydrologic, geomorphologic, and ecologic processes operate on different temporal scales, generating bidirectional feedback loops over space and time. Hydro- and geomorphologic processes, operating episodically during bankfull conditions, influence ecological processes (e.g., biogeochemical cycling) occurring over longer time periods during base-flow conditions. This ecological activity generates the antecedent conditions that influence the hydro- and geomorphologic processes occurring during the next high flow event, creating a bidirectional feedback. This feedback should enhance the resiliency of fluvial landforms and ecosystem processes, allowing physical and biological processes to pull and push against each other over time.

Ecological and geochemical impacts of exotic earthworm dispersal in forest ecosystems of Eastern Canada

NASA Astrophysics Data System (ADS)

Drouin, Melanie; Fugere, Martine; Lapointe, Line; Vellend, Mark; Bradley, Robert L.

2016-04-01

In Eastern Canada, native earthworm species did not survive the Wisconsin glaciation, which ended over 11,000 years ago. Accordingly, the 17 known Lumbricidae species in the province of Québec were introduced in recent centuries by European settlers. Given that natural migration rates are no more than 5-10 m yr-1, exotic earthworm dispersal across the landscape is presumed to be mediated by human activities, although this assertion needs further validation. In agroecosystems, earthworms have traditionally been considered beneficial soil organisms that facilitate litter decomposition, increase nutrient availability and improve soil structure. However, earthworm activities could also increase soil nutrient leaching and CO2 emissions. Furthermore, in natural forest ecosystems, exotic earthworms may reduce organic forest floors provoking changes in watershed hydrology and loss of habitat for some faunal species. Over the past decade, studies have also suggested a negative effect of exotic earthworms on understory plant diversity, but the underlying mechanisms remain elusive. Finally, there are no studies to our knowledge that have tested the effects of Lumbricidae species on the production of N2O (an important greenhouse gas) in forest ecosystems. We report on a series of field, greenhouse and laboratory studies on the human activities responsible for the dispersal of exotic earthworms, and on their ecological / geochemical impacts in natural forest ecosystems. Our results show: (1) Car tire treads and bait discarded by fishermen are important human vectors driving the dispersal of earthworms into northern temperate forests; (2) Exotic earthworms significantly modify soil physicochemical properties, nutrient cycling, microbial community structure and biomass; (3) Earthworm abundances in the field correlate with a decrease in understory plant diversity; (4) Lumbricus terrestris, an anecic earthworm species and favorite bait of fishermen, reduces seed germination and seedling survival of some temperate and boreal trees species; (5) The abundance of L. terrestris correlates with higher potential rates of N2O production. Taken collectively, our data provide scientific evidence that earthworm dispersal mitigation strategies are required to conserve the ecological integrity of forest ecosystems in Eastern Canada.

Reverse Ecology: from systems to environments and back.

PubMed

Levy, Roie; Borenstein, Elhanan

2012-01-01

The structure of complex biological systems reflects not only their function but also the environments in which they evolved and are adapted to. Reverse Ecology-an emerging new frontier in Evolutionary Systems Biology-aims to extract this information and to obtain novel insights into an organism's ecology. The Reverse Ecology framework facilitates the translation of high-throughput genomic data into large-scale ecological data, and has the potential to transform ecology into a high-throughput field. In this chapter, we describe some of the pioneering work in Reverse Ecology, demonstrating how system-level analysis of complex biological networks can be used to predict the natural habitats of poorly characterized microbial species, their interactions with other species, and universal patterns governing the adaptation of organisms to their environments. We further present several studies that applied Reverse Ecology to elucidate various aspects of microbial ecology, and lay out exciting future directions and potential future applications in biotechnology, biomedicine, and ecological engineering.

Study on ecological conservation planning of Xianyue Park in Xiamen City, China

NASA Astrophysics Data System (ADS)

Xu, Naizhong; Xi, Rong; Ren, Tingyan; Zhao, Peng; Chuai, Zeyao

2017-08-01

The paper discusses the current situation and existing problems of ecological restoration and tourist infrastructure development of Xiamen Xianyue Park located in Xiamen Island, China. Issues of ecosystem restoration and landscape improvement, restoring habitats, and ecosystem management system are analyzed. Options of further optimization of the tourist-targeted infrastructure are proposed, which take into account the ecological system and landscape pattern optimization, promotion of ecotourism, and implementation of the ecological management system. The particular solution envisages the park zoning with three primary zones (ecological protection, ecological buffer, and general activity zones) and five secondary ones (scenic landscape, ecotourism, religious activity, buildings and structures, and entertainment zones). By integrating the ecological principles into other land use objectives, taking full advantage of the park ecological and cultural heritage, and improving its ecological management, it is expected to provide the ecological restoration of the park under study and optimize its contribution to the regional economic and social development.

Innovative Additive for Bitumen Based on Processed Fats

NASA Astrophysics Data System (ADS)

Babiak, Michał; Kosno, Jacek; Ratajczak, Maria; Zieliński, Krzysztof

2017-10-01

Various additives, admixtures and modifiers are used to improve technical properties and strength characteristics of building materials. Manufacturers of waterproofing materials, concrete, ceramics and bitumen have to use innovative, increasingly complex and costly additives, admixtures or modifiers. As a result, simple and inexpensive substances have been replaced by complex, long chain polymers, multi component resins or plastics. For economic and ecological reasons waste materials are more frequently used as additives, admixtures and modifiers. Nowadays the most commonly used physical modifiers of bitumen belong to the group of polymers - large molecular organic compounds of natural origin or being the result of planned chemical synthesis. Polymers are substances that do not chemically react with bitumen, they act as fillers or create a spatial network within bitumen (the so called physical cross-linking). The development of organic chemistry has allowed the synthesis of a number of substances chemically modifying bitumen. The most promising are heterocyclic organic compounds belonging to the group of imidazolines. The aim of the study presented in this paper was to demonstrate the suitability of processed natural and post-refining fat waste (diamidoamine dehydrate) as bitumen modifier. This paper discusses the impact of adding technical imidazoline on selected bitumen characteristics. Samples of bitumen 160/220, which is most commonly used for the production of waterproofing products, were analysed. For base bitumen and bitumen modified with technical imidazoline the following measurements were taken: measurement of the softening point by Ball and Ring method, determination of the breaking point by Fraass method and needle penetration measurement at 25°C. Later the samples were aged using TFOT laboratory method and the basic characteristics were determined again. The results showed that a small amount of imidazoline improved bitumen thermoplastic parameters at low temperatures and had a significant impact on weakening bitumen oxidation and ageing. The addition of technical imidazoline prevents bitumen from hardening, thus increasing its flexibility and its resistance to mechanical damage. Due to many difficulties in the production of polymer bitumens and in order to find cheaper, more environment friendly solutions, the authors proposed an ecological bituminous modifier which, due to chemical reaction with binders, creates a stable and firm in time product. Imidazolines have a negative impact on bitumen softening point, which makes them impossible to use as an independent modifier. Therefore, at a later stage of the research, the authors will attempt to create a hybrid bitumen modifier which will combine the beneficial effect of polymers and imidazoline on the characteristics of bituminous binders.

Genetic Engineering and Human Mental Ecology: Interlocking Effects and Educational Considerations.

PubMed

Affifi, Ramsey

2017-01-01

This paper describes some likely semiotic consequences of genetic engineering on what Gregory Bateson has called "the mental ecology" (1979) of future humans, consequences that are less often raised in discussions surrounding the safety of GMOs (genetically modified organisms). The effects are as follows: an increased 1) habituation to the presence of GMOs in the environment, 2) normalization of empirically false assumptions grounding genetic reductionism, 3) acceptance that humans are capable and entitled to decide what constitutes an evolutionary improvement for a species, 4) perception that the main source of creativity and problem solving in the biosphere is anthropogenic. Though there are some tensions between them, these effects tend to produce self-validating webs of ideas, actions, and environments, which may reinforce destructive habits of thought. Humans are unlikely to safely develop genetic technologies without confronting these escalating processes directly. Intervening in this mental ecology presents distinct challenges for educators, as will be discussed.

How Students Manage the Didactic Contract? Contribution of the Didactic Perspective to Research in Physical Education Classroom.

ERIC Educational Resources Information Center

Amade-Escot, Chantal

This study investigated how and why students modified instructional tasks, explaining modifications using the concept of didactic contract. The study focused on two theoretical perspectives in physical education (PE) research: didactic and ecological. The didactic paradigm examines relationships among teachers, students, and the content embedded…

Creative Connecting: Early Childhood Nature Journaling Sparks Wonder and Develops Ecological Literacy

ERIC Educational Resources Information Center

Johnson, Kelly

2014-01-01

While nature journaling with elementary age children has recently increased in popularity, journaling with children of ages 2-6 is often overlooked. This article focuses specifically on why journaling is a valid practice in early childhood and the practitioner application of journaling techniques modified for the young child. Young children have…

The potential impacts of development on wildlands in El Dorado County, California

Treesearch

Shawn C. Saving; Gregory B. Greenwood

2002-01-01

We modeled future development in rapidly urbanizing El Dorado County, California, to assess ecological impacts of expanding urbanization and effectiveness of standard policy mitigation efforts. Using raster land cover data and county parcel data, we constructed a footprint of current development and simulated future development using a modified stochastic flood-fill...

Fire and logging history at Huckleberry Hallow, Shannon County, Missouri

Treesearch

Richard P. Guyette; Daniel C. Dey

1997-01-01

Disturbances such as windthrow, fire and timber harvest significantly effect how forest ecosystems develop. We have and continue to modify the nature of our forests through anthropogenic fire, fire suppression, and resource exploitation and management. Past disturbance histories, as well as current cultural practices and ecological processes, must be considered in...

Climate change and North American rangelands: Assessment of mitigation and adaptation strategies

Treesearch

Linda A. Joyce; David D. Briske; Joel R. Brown; H. Wayne Polley; Bruce A. McCarl; Derek W. Bailey

2013-01-01

Recent climatic trends and climate model projections indicate that climate change will modify rangeland ecosystem functions and the services and livelihoods that they provision. Recent history has demonstrated that climatic variability has a strong influence on both ecological and social components of rangeland systems and that these systems possess substantial...

An Ecological Regional Analysis of South Carolina

ERIC Educational Resources Information Center

Young, Frank W.; Robinson, Kenneth

2011-01-01

This study of the counties of South Carolina introduces a limited purpose, modifiable technology that is designed to reproduce the rapid discovery strategy of the natural sciences. It uses factor analysis to identify types of communities and the threats they face, and evaluates their success in dealing with these by comparisons based on…

Case Study: Transgenic Crop Controversy in Costa Rica

ERIC Educational Resources Information Center

Hague, Steve S.

2009-01-01

Costa Rica has rich ecological resources and has been a steady political force in turbulent Central America. Most recently, it has become a battleground between pro- and anti-genetically modified organism (GMO) political forces. This case study examines the roles of U.S.-based cotton ("Gossypium hirsutum" L.) seed companies, anti-GMO…

The myth of natural barriers. Is transgene introgression by genetically modified crops an environmental risk?

PubMed

Guarnieri, Vincenzo; Benessia, Alice; Camino, Elena; Barbiero, Giuseppe

2008-01-01

Genetically modified (GM) crops under open field conditions are a complex and controversial issue. Ecologists are discussing about the possibility that a transgene belonging to GM plants could spread to native populations through a process known as introgression the stable incorporation of a gene in the host genome able to generate a differentiated population. The ecological consequences of a transgene introgression in plants or bacteria are not yet well understood, but could be significant. In this critical review we consider vertical and horizontal introgression. We analyse the biochemical and genetic constraints, and environmental factors that limit the possibility of transgene spread; meanwhile we show cases in which the natural barriers are overcome. Then we discuss the overall management of GM crops, noting the shortcomings and approximations of risk assessment based on linear thinking typical of the biomolecular approach. Finally we suggest to explicitly weight facts together with values and we encourage the undertaking of an ecological perspective, encompassing the complexity of (non-linear) relations between organisms and the environment.

The bioavailability of chemicals in soil for earthworms

USGS Publications Warehouse

Lanno, R.; Wells, J.; Conder, Jason M.; Bradham, K.; Basta, N.

2004-01-01

The bioavailability of chemicals to earthworms can be modified dramatically by soil physical/chemical characteristics, yet expressing exposure as total chemical concentrations does not address this problem. In order to understand the effects of modifying factors on bioavailability, one must measure and express chemical bioavailability to earthworms in a consistent, logical manner. This can be accomplished by direct biological measures of bioavailability (e.g., bioaccumulation, critical body residues), indirect biological measures of bioavailability (e.g., biomarkers, reproduction), or indirect chemical measures of bioavailability (e.g., chemical or solid-phase extracts of soil). If indirect chemical measures of bioavailability are to be used, they must be correlated with some biological response. Bioavailability can be incorporated into ecological risk assessment during risk analysis, primarily in the estimation of exposure. However, in order to be used in the site-specific ecological risk assessment of chemicals, effects concentrations must be developed from laboratory toxicity tests based on exposure estimates utilizing techniques that measure the bioavailable fraction of chemicals in soil, not total chemical concentrations. ?? 2003 Elsevier Inc. All rights reserved.

Influence of topographic heterogeneity on the abandance of larch forest in eastern Siberia

NASA Astrophysics Data System (ADS)

Sato, H.; Kobayashi, H.

2016-12-01

In eastern Siberia, larches (Larix spp.) often exist in pure stands, constructing the world's largest coniferous forest, of which changes can significantly affect the earth's albedo and the global carbon balance. We have conducted simulation studies for this vegetation, aiming to forecast its structures and functions under changing climate (1, 2). In previous studies of simulating vegetation at large geographical scales, the examining area is divided into coarse grid cells such as 0.5 * 0.5 degree resolution, and topographical heterogeneities within each grid cell are just ignored. However, in Siberian larch area, which is located on the environmental edge of existence of forest ecosystem, abundance of larch trees largely depends on topographic condition at the scale of tens to hundreds meters. We, therefore, analyzed patterns of within-grid-scale heterogeneity of larch LAI as a function of topographic condition, and examined its underlying reason. For this analysis, larch LAI was estimated for each 1/112 degree from the SPOT-VEGETATION data, and topographic properties such as angularity and aspect direction were estimated form the ASTER-GDEM data. Through this analysis, we found that, for example, sign of correlation between angularity and larch LAI depends on hydrological condition on the grid cell. We then refined the hydrological sub-model of our vegetation model SEIB-DGVM, and validated whether the modified model can reconstruct these patterns, and examined its impact on the estimation of biomass and vegetation productivity of entire larch region. -- References --1. Sato, H., et al. (2010). "Simulation study of the vegetation structure and function in eastern Siberian larch forests using the individual-based vegetation model SEIB-DGVM." Forest Ecology and Management 259(3): 301-311.2. Sato, H., et al. (2016). "Endurance of larch forest ecosystems in eastern Siberia under warming trends." Ecology and Evolution

From patterns to causal understanding: Structural equation modeling (SEM) in soil ecology

USGS Publications Warehouse

Eisenhauer, Nico; Powell, Jeff R; Grace, James B.; Bowker, Matthew A.

2015-01-01

In this perspectives paper we highlight a heretofore underused statistical method in soil ecological research, structural equation modeling (SEM). SEM is commonly used in the general ecological literature to develop causal understanding from observational data, but has been more slowly adopted by soil ecologists. We provide some basic information on the many advantages and possibilities associated with using SEM and provide some examples of how SEM can be used by soil ecologists to shift focus from describing patterns to developing causal understanding and inspiring new types of experimental tests. SEM is a promising tool to aid the growth of soil ecology as a discipline, particularly by supporting research that is increasingly hypothesis-driven and interdisciplinary, thus shining light into the black box of interactions belowground.

A taxonomic wish-list for community ecology.

PubMed Central

Gotelli, Nicholas J

2004-01-01

Community ecology seeks to explain the number and relative abundance of coexisting species. Four research frontiers in community ecology are closely tied to research in systematics and taxonomy: the statistics of species richness estimators, global patterns of biodiversity, the influence of global climate change on community structure, and phylogenetic influences on community structure. The most pressing needs for taxonomic information in community ecology research are usable taxonomic keys, current nomenclature, species occurrence records and resolved phylogenies. These products can best be obtained from Internet-based phylogenetic and taxonomic resources, but the lack of trained professional systematists and taxonomists threatens this effort. Community ecologists will benefit most directly from research in systematics and taxonomy by making better use of resources in museums and herbaria, and by actively seeking training, information and collaborations with taxonomic specialists. PMID:15253346

The role of ecological theory in microbial ecology.

PubMed

Prosser, James I; Bohannan, Brendan J M; Curtis, Tom P; Ellis, Richard J; Firestone, Mary K; Freckleton, Rob P; Green, Jessica L; Green, Laura E; Killham, Ken; Lennon, Jack J; Osborn, A Mark; Solan, Martin; van der Gast, Christopher J; Young, J Peter W

2007-05-01

Microbial ecology is currently undergoing a revolution, with repercussions spreading throughout microbiology, ecology and ecosystem science. The rapid accumulation of molecular data is uncovering vast diversity, abundant uncultivated microbial groups and novel microbial functions. This accumulation of data requires the application of theory to provide organization, structure, mechanistic insight and, ultimately, predictive power that is of practical value, but the application of theory in microbial ecology is currently very limited. Here we argue that the full potential of the ongoing revolution will not be realized if research is not directed and driven by theory, and that the generality of established ecological theory must be tested using microbial systems.

Ecological Assets and Academic Procrastination among Adolescents: The Mediating Role of Commitment to Learning.

PubMed

Chen, Bin-Bin; Han, Wen

2017-01-01

Academic procrastination is defined as a purposive delay of academic tasks that must be completed. Within the framework of the ecological model of resiliency, this study examined how ecological assets were related to academic procrastination among adolescents. Participants in the study were 577 adolescents (53.5% boys) from Shanghai, China. They completed measures of ecological assets, commitment to learning, and academic procrastination. Structural equation modeling revealed that, as predicted, ecological assets were negatively associated with academic procrastination. In addition, commitment to learning fully mediated the association between ecological assets and academic procrastination. Implications of the present findings are discussed.

Ecological Assets and Academic Procrastination among Adolescents: The Mediating Role of Commitment to Learning

PubMed Central

Chen, Bin-Bin; Han, Wen

2017-01-01

Academic procrastination is defined as a purposive delay of academic tasks that must be completed. Within the framework of the ecological model of resiliency, this study examined how ecological assets were related to academic procrastination among adolescents. Participants in the study were 577 adolescents (53.5% boys) from Shanghai, China. They completed measures of ecological assets, commitment to learning, and academic procrastination. Structural equation modeling revealed that, as predicted, ecological assets were negatively associated with academic procrastination. In addition, commitment to learning fully mediated the association between ecological assets and academic procrastination. Implications of the present findings are discussed. PMID:29379451

The movement ecology and dynamics of plant communities in fragmented landscapes.

PubMed

Damschen, Ellen I; Brudvig, Lars A; Haddad, Nick M; Levey, Douglas J; Orrock, John L; Tewksbury, Joshua J

2008-12-09

A conceptual model of movement ecology has recently been advanced to explain all movement by considering the interaction of four elements: internal state, motion capacity, navigation capacities, and external factors. We modified this framework to generate predictions for species richness dynamics of fragmented plant communities and tested them in experimental landscapes across a 7-year time series. We found that two external factors, dispersal vectors and habitat features, affected species colonization and recolonization in habitat fragments and their effects varied and depended on motion capacity. Bird-dispersed species richness showed connectivity effects that reached an asymptote over time, but no edge effects, whereas wind-dispersed species richness showed steadily accumulating edge and connectivity effects, with no indication of an asymptote. Unassisted species also showed increasing differences caused by connectivity over time, whereas edges had no effect. Our limited use of proxies for movement ecology (e.g., dispersal mode as a proxy for motion capacity) resulted in moderate predictive power for communities and, in some cases, highlighted the importance of a more complete understanding of movement ecology for predicting how landscape conservation actions affect plant community dynamics.

Plant Insecticidal Toxins in Ecological Networks

PubMed Central

Ibanez, Sébastien; Gallet, Christiane; Després, Laurence

2012-01-01

Plant secondary metabolites play a key role in plant-insect interactions, whether constitutive or induced, C- or N-based. Anti-herbivore defences against insects can act as repellents, deterrents, growth inhibitors or cause direct mortality. In turn, insects have evolved a variety of strategies to act against plant toxins, e.g., avoidance, excretion, sequestration and degradation of the toxin, eventually leading to a co-evolutionary arms race between insects and plants and to co-diversification. Anti-herbivore defences also negatively impact mutualistic partners, possibly leading to an ecological cost of toxin production. However, in other cases toxins can also be used by plants involved in mutualistic interactions to exclude inadequate partners and to modify the cost/benefit ratio of mutualism to their advantage. When considering the whole community, toxins have an effect at many trophic levels. Aposematic insects sequester toxins to defend themselves against predators. Depending on the ecological context, toxins can either increase insects’ vulnerability to parasitoids and entomopathogens or protect them, eventually leading to self-medication. We conclude that studying the community-level impacts of plant toxins can provide new insights into the synthesis between community and evolutionary ecology. PMID:22606374

The evolutionary and ecological consequences of animal social networks: emerging issues.

PubMed

Kurvers, Ralf H J M; Krause, Jens; Croft, Darren P; Wilson, Alexander D M; Wolf, Max

2014-06-01

The first generation of research on animal social networks was primarily aimed at introducing the concept of social networks to the fields of animal behaviour and behavioural ecology. More recently, a diverse body of evidence has shown that social fine structure matters on a broader scale than initially expected, affecting many key ecological and evolutionary processes. Here, we review this development. We discuss the effects of social network structure on evolutionary dynamics (genetic drift, fixation probabilities, and frequency-dependent selection) and social evolution (cooperation and between-individual behavioural differences). We discuss how social network structure can affect important coevolutionary processes (host-pathogen interactions and mutualisms) and population stability. We also discuss the potentially important, but poorly studied, role of social network structure on dispersal and invasion. Throughout, we highlight important areas for future research. Copyright © 2014 Elsevier Ltd. All rights reserved.

Implicit Statistical Learning in Real-World Environments Leads to Ecologically Rational Decision Making.

PubMed

Perkovic, Sonja; Orquin, Jacob Lund

2018-01-01

Ecological rationality results from matching decision strategies to appropriate environmental structures, but how does the matching happen? We propose that people learn the statistical structure of the environment through observation and use this learned structure to guide ecologically rational behavior. We tested this hypothesis in the context of organic foods. In Study 1, we found that products from healthful food categories are more likely to be organic than products from nonhealthful food categories. In Study 2, we found that consumers' perceptions of the healthfulness and prevalence of organic products in many food categories are accurate. Finally, in Study 3, we found that people perceive organic products as more healthful than nonorganic products when the statistical structure justifies this inference. Our findings suggest that people believe organic foods are more healthful than nonorganic foods and use an organic-food cue to guide their behavior because organic foods are, on average, 30% more healthful.

Density dependence in group dynamics of a highly social mongoose, Suricata suricatta.

PubMed

Bateman, Andrew W; Ozgul, Arpat; Coulson, Tim; Clutton-Brock, Tim H

2012-05-01

1. For social species, the link between individual behaviour and population dynamics is mediated by group-level demography. 2. Populations of obligate cooperative breeders are structured into social groups, which may be subject to inverse density dependence (Allee effects) that result from a dependence on conspecific helpers, but evidence for population-wide Allee effects is rare. 3. We use field data from a long-term study of cooperative meerkats (Suricata suricatta; Schreber, 1776) - a species for which local Allee effects are not reflected in population-level dynamics - to empirically model interannual group dynamics. 4. Using phenomenological population models, modified to incorporate environmental conditions and potential Allee effects, we first investigate overall patterns of group dynamics and find support only for conventional density dependence that increases after years of low rainfall. 5. To explain the observed patterns, we examine specific demographic rates and assess their contributions to overall group dynamics. Although per-capita meerkat mortality is subject to a component Allee effect, it contributes relatively little to observed variation in group dynamics, and other (conventionally density dependent) demographic rates - especially emigration - govern group dynamics. 6. Our findings highlight the need to consider demographic processes and density dependence in subpopulations before drawing conclusions about how behaviour affects population processes in socially complex systems. © 2011 The Authors. Journal of Animal Ecology © 2011 British Ecological Society.

African Migrant Patients’ Trust in Chinese Physicians: A Social Ecological Approach to Understanding Patient-Physician Trust

PubMed Central

McLaughlin, Megan M.; Simonson, Louis; Zou, Xia; Ling, Li; Tucker, Joseph D.

2015-01-01

Background Patient trust in physicians is a critical determinant of health seeking behaviors, medication adherence, and health outcomes. A crisis of interpersonal trust exists in China, extending throughout multiple social spheres, including the healthcare system. At the same time, with increased migration from Africa to China in the last two decades, Chinese physicians must establish mutual trust with an increasingly diverse patient population. We undertook a qualitative study to identify factors affecting African migrants’ trust in Chinese physicians and to identify potential mechanisms for promoting trust. Methods / Principal Findings We conducted semi-structured, in-depth interviews with 40 African migrants in Guangzhou, China. A modified version of the social ecological model was used as a theoretical framework. At the patient-physician level, interpersonal treatment, technical competence, perceived commitment and motive, and language concordance were associated with enhanced trust. At the health system level, two primary factors influenced African migrants’ trust in their physicians: the fee-for-service payment system and lack of continuity with any one physician. Patients’ social networks and the broader socio-cultural context of interactions between African migrants and Chinese locals also influenced patients’ trust of their physicians. Conclusions These findings demonstrate the importance of factors beyond the immediate patient-physician interaction and suggest opportunities to promote trust through health system interventions. PMID:25965064

Effects of dams on downstream molluscan predator-prey interactions in the Colorado River estuary.

PubMed

Smith, Jansen A; Handley, John C; Dietl, Gregory P

2018-05-30

River systems worldwide have been modified for human use and the downstream ecological consequences are often poorly understood. In the Colorado River estuary, where upstream water diversions have limited freshwater input during the last century, mollusc remains from the last several hundred years suggest widespread ecological change. The once abundant clam Mulinia modesta has undergone population declines of approximately 94% and populations of predators relying on this species as a food source have probably declined, switched to alternative prey species or both. We distinguish between the first two hypotheses using a null model of predation preference to test whether M. modesta was preyed upon selectively by the naticid snail, Neverita reclusiana , along the estuary's past salinity gradient. To evaluate the third hypothesis, we estimate available prey biomass today and in the past, assuming prey were a limiting resource. Data on the frequency of drill holes-identifiable traces of naticid predation on prey shells-showed several species, including M. modesta , were preferred prey. Neverita reclusiana was probably able to switch prey. Available prey biomass also declined, suggesting the N. reclusiana population probably also declined. These results indicate a substantial change to the structure of the benthic food web. Given the global scale of water management, such changes have probably also occurred in many of the world's estuaries. © 2018 The Author(s).

Physical disturbance to ecological niches created by soil structure alters community composition of methanotrophs.

PubMed

Kumaresan, Deepak; Stralis-Pavese, Nancy; Abell, Guy C J; Bodrossy, Levente; Murrell, J Colin

2011-10-01

Aggregates of different sizes and stability in soil create a composite of ecological niches differing in terms of physico-chemical and structural characteristics. The aim of this study was to identify, using DNA-SIP and mRNA-based microarray analysis, whether shifts in activity and community composition of methanotrophs occur when ecological niches created by soil structure are physically perturbed. Landfill cover soil was subject to three treatments termed: 'control' (minimal structural disruption), 'sieved' (sieved soil using 2 mm mesh) and 'ground' (grinding using mortar and pestle). 'Sieved' and 'ground' soil treatments exhibited higher methane oxidation potentials compared with the 'control' soil treatment. Analysis of the active community composition revealed an effect of physical disruption on active methanotrophs. Type I methanotrophs were the most active methanotrophs in 'sieved' and 'ground' soil treatments, whereas both Type I and Type II methanotrophs were active in the 'control' soil treatment. The result emphasize that changes to a particular ecological niche may not result in an immediate change to the active bacterial composition and change in composition will depend on the ability of the bacterial communities to respond to the perturbation. © 2011 Society for Applied Microbiology and Blackwell Publishing Ltd.

Ecological-network models link diversity, structure and function in the plankton food-web

NASA Astrophysics Data System (ADS)

D'Alelio, Domenico; Libralato, Simone; Wyatt, Timothy; Ribera D'Alcalà, Maurizio

2016-02-01

A planktonic food-web model including sixty-three functional nodes (representing auto- mixo- and heterotrophs) was developed to integrate most trophic diversity present in the plankton. The model was implemented in two variants - which we named ‘green’ and ‘blue’ - characterized by opposite amounts of phytoplankton biomass and representing, respectively, bloom and non-bloom states of the system. Taxonomically disaggregated food-webs described herein allowed to shed light on how components of the plankton community changed their trophic behavior in the two different conditions, and modified the overall functioning of the plankton food web. The green and blue food-webs showed distinct organizations in terms of trophic roles of the nodes and carbon fluxes between them. Such re-organization stemmed from switches in selective grazing by both metazoan and protozoan consumers. Switches in food-web structure resulted in relatively small differences in the efficiency of material transfer towards higher trophic levels. For instance, from green to blue states, a seven-fold decrease in phytoplankton biomass translated into only a two-fold decrease in potential planktivorous fish biomass. By linking diversity, structure and function in the plankton food-web, we discuss the role of internal mechanisms, relying on species-specific functionalities, in driving the ‘adaptive’ responses of plankton communities to perturbations.

Conservation success as a function of good alignment of social and ecological structures and processes.

PubMed

Bodin, Orjan; Crona, Beatrice; Thyresson, Matilda; Golz, Anna-Lea; Tengö, Maria

2014-10-01

How to create and adjust governing institutions so that they align (fit) with complex ecosystem processes and structures across scales is an issue of increasing concern in conservation. It is argued that lack of such social-ecological fit makes governance and conservation difficult, yet progress in explicitly defining and rigorously testing what constitutes a good fit has been limited. We used a novel modeling approach and data from case studies of fishery and forest conservation to empirically test presumed relationships between conservation outcomes and certain patterns of alignment of social-ecological interdependences. Our approach made it possible to analyze conservation outcome on a systems level while also providing information on how individual actors are positioned in the complex web of social-ecological interdependencies. We found that when actors who shared resources were also socially linked, conservation at the level of the whole social-ecological system was positively affected. When the scales at which individual actors used resources and the scale at which ecological resources were interconnected to other ecological resources were aligned through tightened feedback loops, conservation outcome was better than when they were not aligned. The analysis of individual actors' positions in the web of social-ecological interdependencies was helpful in understanding why a system has a certain level of social-ecological fit. Results of analysis of positions showed that different actors contributed in very different ways to achieve a certain fit and revealed some underlying difference between the actors, for example in terms of actors' varying rights to access and use different ecological resources. © 2014 Society for Conservation Biology.

Dry rotary swaging with structured and coated tools

NASA Astrophysics Data System (ADS)

Herrmann, Marius; Schenck, Christian; Kuhfuss, Bernd

2018-05-01

Rotary swaging is a cold bulk forming process for manufacturing of complex bar and tube profiles like axles and gear shafts in the automotive industry. Conventional rotary swaging is carried out under intense use of lubricant usually based on mineral oil. Besides lubrication the lubricant fulfills necessary functions like lubrication, flushing and cooling, but generates costs for recycling, replacement and cleaning of the workpieces. Hence, the development of a dry process design is highly desirable, both under economic and ecological points of view. Therefore, it is necessary to substitute the functions of the lubricant. This was realized by the combination of newly developed a-C:H:W coating systems on the tools to minimize the friction and to avoid adhesion effects. With the application of a deterministic structure in the forging zone of the tools the friction conditions are modified to control the axial process forces. In this study infeed rotary swaging with functionalized tools was experimentally investigated. Therefore, steel and aluminum tubes were formed with and without lubricant. Different structures which were coated and uncoated were implemented in the reduction zone of the tools. The antagonistic effects of coating and structuring were characterized by measuring the axial process force and the produced workpiece quality in terms of roundness and surface roughness. Thus, the presented results allow for further developments towards a dry rotary swaging process.

Community ecology in a changing environment: Perspectives from the Quaternary

NASA Astrophysics Data System (ADS)

Jackson, Stephen T.; Blois, Jessica L.

2015-04-01

Community ecology and paleoecology are both concerned with the composition and structure of biotic assemblages but are largely disconnected. Community ecology focuses on existing species assemblages and recently has begun to integrate history (phylogeny and continental or intercontinental dispersal) to constrain community processes. This division has left a "missing middle": Ecological and environmental processes occurring on timescales from decades to millennia are not yet fully incorporated into community ecology. Quaternary paleoecology has a wealth of data documenting ecological dynamics at these timescales, and both fields can benefit from greater interaction and articulation. We discuss ecological insights revealed by Quaternary terrestrial records, suggest foundations for bridging between the disciplines, and identify topics where the disciplines can engage to mutual benefit.

Community ecology in a changing environment: Perspectives from the Quaternary

PubMed Central

Jackson, Stephen T.; Blois, Jessica L.

2015-01-01

Community ecology and paleoecology are both concerned with the composition and structure of biotic assemblages but are largely disconnected. Community ecology focuses on existing species assemblages and recently has begun to integrate history (phylogeny and continental or intercontinental dispersal) to constrain community processes. This division has left a “missing middle”: Ecological and environmental processes occurring on timescales from decades to millennia are not yet fully incorporated into community ecology. Quaternary paleoecology has a wealth of data documenting ecological dynamics at these timescales, and both fields can benefit from greater interaction and articulation. We discuss ecological insights revealed by Quaternary terrestrial records, suggest foundations for bridging between the disciplines, and identify topics where the disciplines can engage to mutual benefit. PMID:25901314

Community ecology in a changing environment: Perspectives from the Quaternary

USGS Publications Warehouse

Jackson, Stephen T.; Blois, Jessica L.

2015-01-01

Community ecology and paleoecology are both concerned with the composition and structure of biotic assemblages but are largely disconnected. Community ecology focuses on existing species assemblages and recently has begun to integrate history (phylogeny and continental or intercontinental dispersal) to constrain community processes. This division has left a “missing middle”: Ecological and environmental processes occurring on timescales from decades to millennia are not yet fully incorporated into community ecology. Quaternary paleoecology has a wealth of data documenting ecological dynamics at these timescales, and both fields can benefit from greater interaction and articulation. We discuss ecological insights revealed by Quaternary terrestrial records, suggest foundations for bridging between the disciplines, and identify topics where the disciplines can engage to mutual benefit.

Community ecology in a changing environment: Perspectives from the Quaternary.

PubMed

Jackson, Stephen T; Blois, Jessica L

2015-04-21

Community ecology and paleoecology are both concerned with the composition and structure of biotic assemblages but are largely disconnected. Community ecology focuses on existing species assemblages and recently has begun to integrate history (phylogeny and continental or intercontinental dispersal) to constrain community processes. This division has left a "missing middle": Ecological and environmental processes occurring on timescales from decades to millennia are not yet fully incorporated into community ecology. Quaternary paleoecology has a wealth of data documenting ecological dynamics at these timescales, and both fields can benefit from greater interaction and articulation. We discuss ecological insights revealed by Quaternary terrestrial records, suggest foundations for bridging between the disciplines, and identify topics where the disciplines can engage to mutual benefit.

Seasonal change of topology and resilience of ecological networks in wetlandscapes

NASA Astrophysics Data System (ADS)

Bin, Kim; Park, Jeryang

2017-04-01

Wetlands distributed in a landscape provide various ecosystem services including habitat for flora and fauna, hydrologic controls, and biogeochemical processes. Hydrologic regime of each wetland at a given landscape varies by hydro-climatic and geological conditions as well as the bathymetry, forming a certain pattern in the wetland area distribution and spatial organization. However, its large-scale pattern also changes over time as this wetland complex is subject to stochastic hydro-climatic forcing in various temporal scales. Consequently, temporal variation in the spatial structure of wetlands inevitably affects the dispersal ability of species depending on those wetlands as habitat. Here, we numerically show (1) the spatiotemporal variation of wetlandscapes by forcing seasonally changing stochastic rainfall and (2) the corresponding ecological networks which either deterministically or stochastically forming the dispersal ranges. We selected four vernal pool regions with distinct climate conditions in California. The results indicate that the spatial structure of wetlands in a landscape by measuring the wetland area frequency distribution changes by seasonal hydro-climatic condition but eventually recovers to the initial state. However, the corresponding ecological networks, which the structure and function change by the change of distances between wetlands, and measured by degree distribution and network efficiency, may not recover to the initial state especially in the regions with high seasonal dryness index. Moreover, we observed that the changes in both the spatial structure of wetlands in a landscape and the corresponding ecological networks exhibit hysteresis over seasons. Our analysis indicates that the hydrologic and ecological resilience of a wetlandcape may be low in a dry region with seasonal hydro-climatic forcing. Implications of these results for modelling ecological networks depending on hydrologic systems especially for conservation purposes are discussed.

Radiating despite a Lack of Character: Ecological Divergence among Closely Related, Morphologically Similar Honeyeaters (Aves: Meliphagidae) Co-occurring in Arid Australian Environments.

PubMed

Miller, Eliot T; Wagner, Sarah K; Harmon, Luke J; Ricklefs, Robert E

2017-02-01

Quantifying the relationship between form and function can inform use of morphology as a surrogate for ecology. How the strength of this relationship varies continentally can inform understanding of evolutionary radiations; for example, does the relationship break down when certain lineages invade and diversify in novel habitats? The 75 species of Australian honeyeaters (Meliphagidae) are morphologically and ecologically diverse, with species feeding on nectar, insects, fruit, and other resources. We investigated Meliphagidae ecomorphology and community structure by (1) quantifying the concordance between morphology and ecology (foraging behavior), (2) estimating rates of trait evolution in relation to the packing of ecological space, and (3) comparing phylogenetic and trait community structure across the broad environmental gradients of the continent. We found that morphology explained 37% of the variance in ecology (and 62% vice versa), and we uncovered well-known bivariate relationships among the multivariate ecomorphological data. Ecological trait diversity declined less rapidly than phylogenetic diversity along a gradient of decreasing precipitation. We employ a new method (trait fields) and extend another (phylogenetic fields) to show that while species in phylogenetically clustered, arid-environment assemblages are similar morphologically, they are as varied in foraging behavior as those from more diverse assemblages. Thus, although closely related and similar morphologically, these arid-adapted species have diverged in ecological space to a similar degree as their mesic counterparts.

Multiple successional pathways in human-modified tropical landscapes: new insights from forest succession, forest fragmentation and landscape ecology research.

PubMed

Arroyo-Rodríguez, Víctor; Melo, Felipe P L; Martínez-Ramos, Miguel; Bongers, Frans; Chazdon, Robin L; Meave, Jorge A; Norden, Natalia; Santos, Bráulio A; Leal, Inara R; Tabarelli, Marcelo

2017-02-01

Old-growth tropical forests are being extensively deforested and fragmented worldwide. Yet forest recovery through succession has led to an expansion of secondary forests in human-modified tropical landscapes (HMTLs). Secondary forests thus emerge as a potential repository for tropical biodiversity, and also as a source of essential ecosystem functions and services in HMTLs. Such critical roles are controversial, however, as they depend on successional, landscape and socio-economic dynamics, which can vary widely within and across landscapes and regions. Understanding the main drivers of successional pathways of disturbed tropical forests is critically needed for improving management, conservation, and restoration strategies. Here, we combine emerging knowledge from tropical forest succession, forest fragmentation and landscape ecology research to identify the main driving forces shaping successional pathways at different spatial scales. We also explore causal connections between land-use dynamics and the level of predictability of successional pathways, and examine potential implications of such connections to determine the importance of secondary forests for biodiversity conservation in HMTLs. We show that secondary succession (SS) in tropical landscapes is a multifactorial phenomenon affected by a myriad of forces operating at multiple spatio-temporal scales. SS is relatively fast and more predictable in recently modified landscapes and where well-preserved biodiversity-rich native forests are still present in the landscape. Yet the increasing variation in landscape spatial configuration and matrix heterogeneity in landscapes with intermediate levels of disturbance increases the uncertainty of successional pathways. In landscapes that have suffered extensive and intensive human disturbances, however, succession can be slow or arrested, with impoverished assemblages and reduced potential to deliver ecosystem functions and services. We conclude that: (i) succession must be examined using more comprehensive explanatory models, providing information about the forces affecting not only the presence but also the persistence of species and ecological groups, particularly of those taxa expected to be extirpated from HMTLs; (ii) SS research should integrate new aspects from forest fragmentation and landscape ecology research to address accurately the potential of secondary forests to serve as biodiversity repositories; and (iii) secondary forest stands, as a dynamic component of HMTLs, must be incorporated as key elements of conservation planning; i.e. secondary forest stands must be actively managed (e.g. using assisted forest restoration) according to conservation goals at broad spatial scales. © 2015 Cambridge Philosophical Society.

An integrated multi-criteria scenario evaluation web tool for participatory land-use planning in urbanized areas: The Ecosystem Portfolio Model

USGS Publications Warehouse

Labiosa, Bill; Forney, William M.; Hearn,, Paul P.; Hogan, Dianna M.; Strong, David R.; Swain, Eric D.; Esnard, Ann-Margaret; Mitsova-Boneva, D.; Bernknopf, R.; Pearlstine, Leonard; Gladwin, Hugh

2013-01-01

Land-use land-cover change is one of the most important and direct drivers of changes in ecosystem functions and services. Given the complexity of the decision-making, there is a need for Internet-based decision support systems with scenario evaluation capabilities to help planners, resource managers and communities visualize, compare and consider trade-offs among the many values at stake in land use planning. This article presents details on an Ecosystem Portfolio Model (EPM) prototype that integrates ecological, socio-economic information and associated values of relevance to decision-makers and stakeholders. The EPM uses a multi-criteria scenario evaluation framework, Geographic Information Systems (GIS) analysis and spatially-explicit land-use/land-cover change-sensitive models to characterize changes in important land-cover related ecosystem values related to ecosystem services and functions, land parcel prices, and community quality-of-life (QoL) metrics. Parameters in the underlying models can be modified through the interface, allowing users in a facilitated group setting to explore simultaneously issues of scientific uncertainty and divergence in the preferences of stakeholders. One application of the South Florida EPM prototype reported in this article shows the modeled changes (which are significant) in aggregate ecological value, landscape patterns and fragmentation, biodiversity potential and ecological restoration potential for current land uses compared to the 2050 land-use scenario. Ongoing refinements to EPM, and future work especially in regard to modifiable sea level rise scenarios are also discussed.

Procedure to select test organisms for environmental risk assessment of genetically modified crops in aquatic systems.

PubMed

Hilbeck, Angelika; Bundschuh, Rebecca; Bundschuh, Mirco; Hofmann, Frieder; Oehen, Bernadette; Otto, Mathias; Schulz, Ralf; Trtikova, Miluse

2017-11-01

For a long time, the environmental risk assessment (ERA) of genetically modified (GM) crops focused mainly on terrestrial ecosystems. This changed when it was scientifically established that aquatic ecosystems are exposed to GM crop residues that may negatively affect aquatic species. To assist the risk assessment process, we present a tool to identify ecologically relevant species usable in tiered testing prior to authorization or for biological monitoring in the field. The tool is derived from a selection procedure for terrestrial ecosystems with substantial but necessary changes to adequately consider the differences in the type of ecosystems. By using available information from the Water Framework Directive (2000/60/EC), the procedure can draw upon existing biological data on aquatic systems. The proposed procedure for aquatic ecosystems was tested for the first time during an expert workshop in 2013, using the cultivation of Bacillus thuringiensis (Bt) maize as the GM crop and 1 stream type as the receiving environment in the model system. During this workshop, species executing important ecological functions in aquatic environments were identified in a stepwise procedure according to predefined ecological criteria. By doing so, we demonstrated that the procedure is practicable with regard to its goal: From the initial long list of 141 potentially exposed aquatic species, 7 species and 1 genus were identified as the most suitable candidates for nontarget testing programs. Integr Environ Assess Manag 2017;13:974-979. © 2017 SETAC. © 2017 SETAC.

[Urban ecological risk assessment: a review].

PubMed

Wang, Mei-E; Chen, Wei-Ping; Peng, Chi

2014-03-01

With the development of urbanization and the degradation of urban living environment, urban ecological risks caused by urbanization have attracted more and more attentions. Based on urban ecology principles and ecological risk assessment frameworks, contents of urban ecological risk assessment were reviewed in terms of driven forces, risk resources, risk receptors, endpoints and integrated approaches for risk assessment. It was suggested that types and degrees of urban economical and social activities were the driven forces for urban ecological risks. Ecological functional components at different levels in urban ecosystems as well as the urban system as a whole were the risk receptors. Assessment endpoints involved in changes of urban ecological structures, processes, functional components and the integrity of characteristic and function. Social-ecological models should be the major approaches for urban ecological risk assessment. Trends for urban ecological risk assessment study should focus on setting a definite protection target and criteria corresponding to assessment endpoints, establishing a multiple-parameter assessment system and integrative assessment approaches.

The problem of ecological scaling in spatially complex, nonequilibrium ecological systems [chapter 3

Treesearch

Samuel A. Cushman; Jeremy Littell; Kevin McGarigal

2010-01-01

In the previous chapter we reviewed the challenges posed by spatial complexity and temporal disequilibrium to efforts to understand and predict the structure and dynamics of ecological systems. The central theme was that spatial variability in the environment and population processes fundamentally alters the interactions between species and their environments, largely...

Guide to the ecological systems of Puerto Rico

Treesearch

G. Miller; A.E. Lugo

2009-01-01

This guide is an introduction to the ecological systems of Puerto Rico. It covers the diversity of ecological systems in the island, their most common plant and animal species, and salient aspects of their structure and functioning. Terrestrial, wetland, coastal, and marine ecosystems are included, as well as agroforest and urban systems. The discussion of the...

Facing the Heat: Does Desiccation and Thermal Stress Explain Patterns of Orientation in an Intertidal Invertebrate?

PubMed

Fraser, Clarissa M L; Seebacher, Frank; Lathlean, Justin; Coleman, Ross A

2016-01-01

A key challenge for ecologists is to quantify, explain and predict the ecology and behaviour of animals from knowledge of their basic physiology. Compared to our knowledge of many other types of distribution and behaviour, and how these are linked to individual function, we have a poor level of understanding of the causal basis for orientation behaviours. Most explanations for patterns of animal orientation assume that animals will modify their exposure to environmental factors by altering their orientation. We used a keystone grazer on rocky shores, the limpet Cellana tramoserica, to test this idea. Manipulative experiments were done to evaluate whether orientation during emersion affected limpet desiccation or body temperature. Body temperature was determined from infrared thermography, a technique that minimises disturbance to the test organism. No causal relationships were found between orientation and (i) level of desiccation and (ii) their body temperature. These results add to the growing knowledge that responses to desiccation and thermal stress may be less important in modifying the behaviour of intertidal organisms than previously supposed and that thermoregulation does not always reflect patterns of animal orientation. Much of what we understand about orientation comes from studies of animals able to modify orientation over very short time scales. Our data suggests that for animals whose location is less flexible, orientation decisions may have less to do with responses to environmental factors and more to do with structural habitat properties or intrinsic individual attributes. Therefore we suggest future studies into processes affecting orientation must include organisms with differing levels of behavioural plasticity.

Facing the Heat: Does Desiccation and Thermal Stress Explain Patterns of Orientation in an Intertidal Invertebrate?

PubMed Central

Fraser, Clarissa M. L.; Seebacher, Frank; Lathlean, Justin; Coleman, Ross A.

2016-01-01

A key challenge for ecologists is to quantify, explain and predict the ecology and behaviour of animals from knowledge of their basic physiology. Compared to our knowledge of many other types of distribution and behaviour, and how these are linked to individual function, we have a poor level of understanding of the causal basis for orientation behaviours. Most explanations for patterns of animal orientation assume that animals will modify their exposure to environmental factors by altering their orientation. We used a keystone grazer on rocky shores, the limpet Cellana tramoserica, to test this idea. Manipulative experiments were done to evaluate whether orientation during emersion affected limpet desiccation or body temperature. Body temperature was determined from infrared thermography, a technique that minimises disturbance to the test organism. No causal relationships were found between orientation and (i) level of desiccation and (ii) their body temperature. These results add to the growing knowledge that responses to desiccation and thermal stress may be less important in modifying the behaviour of intertidal organisms than previously supposed and that thermoregulation does not always reflect patterns of animal orientation. Much of what we understand about orientation comes from studies of animals able to modify orientation over very short time scales. Our data suggests that for animals whose location is less flexible, orientation decisions may have less to do with responses to environmental factors and more to do with structural habitat properties or intrinsic individual attributes. Therefore we suggest future studies into processes affecting orientation must include organisms with differing levels of behavioural plasticity. PMID:26959815

Does similarity in call structure or foraging ecology explain interspecific information transfer in wild Myotis bats?

PubMed

Hügel, Theresa; van Meir, Vincent; Muñoz-Meneses, Amanda; Clarin, B-Markus; Siemers, Björn M; Goerlitz, Holger R

2017-01-01

Animals can gain important information by attending to the signals and cues of other animals in their environment, with acoustic information playing a major role in many taxa. Echolocation call sequences of bats contain information about the identity and behaviour of the sender which is perceptible to close-by receivers. Increasing evidence supports the communicative function of echolocation within species, yet data about its role for interspecific information transfer is scarce. Here, we asked which information bats extract from heterospecific echolocation calls during foraging. In three linked playback experiments, we tested in the flight room and field if foraging Myotis bats approached the foraging call sequences of conspecifics and four heterospecifics that were similar in acoustic call structure only (acoustic similarity hypothesis), in foraging ecology only (foraging similarity hypothesis), both, or none. Compared to the natural prey capture rate of 1.3 buzzes per minute of bat activity, our playbacks of foraging sequences with 23-40 buzzes/min simulated foraging patches with significantly higher profitability. In the flight room, M. capaccinii only approached call sequences of conspecifics and of the heterospecific M. daubentonii with similar acoustics and foraging ecology. In the field, M. capaccinii and M. daubentonii only showed a weak positive response to those two species. Our results confirm information transfer across species boundaries and highlight the importance of context on the studied behaviour, but cannot resolve whether information transfer in trawling Myotis is based on acoustic similarity only or on a combination of similarity in acoustics and foraging ecology. Animals transfer information, both voluntarily and inadvertently, and within and across species boundaries. In echolocating bats, acoustic call structure and foraging ecology are linked, making echolocation calls a rich source of information about species identity, ecology and activity of the sender, which receivers might exploit to find profitable foraging grounds. We tested in three lab and field experiments if information transfer occurs between bat species and if bats obtain information about ecology from echolocation calls. Myotis capaccinii/daubentonii bats approached call playbacks, but only those from con- and heterospecifics with similar call structure and foraging ecology, confirming interspecific information transfer. Reactions differed between lab and field, emphasising situation-dependent differences in animal behaviour, the importance of field research, and the need for further studies on the underlying mechanism of information transfer and the relative contributions of acoustic and ecological similarity.

The community ecology of pathogens: coinfection, coexistence and community composition.

PubMed

Seabloom, Eric W; Borer, Elizabeth T; Gross, Kevin; Kendig, Amy E; Lacroix, Christelle; Mitchell, Charles E; Mordecai, Erin A; Power, Alison G

2015-04-01

Disease and community ecology share conceptual and theoretical lineages, and there has been a resurgence of interest in strengthening links between these fields. Building on recent syntheses focused on the effects of host community composition on single pathogen systems, we examine pathogen (microparasite) communities using a stochastic metacommunity model as a starting point to bridge community and disease ecology perspectives. Such models incorporate the effects of core community processes, such as ecological drift, selection and dispersal, but have not been extended to incorporate host-pathogen interactions, such as immunosuppression or synergistic mortality, that are central to disease ecology. We use a two-pathogen susceptible-infected (SI) model to fill these gaps in the metacommunity approach; however, SI models can be intractable for examining species-diverse, spatially structured systems. By placing disease into a framework developed for community ecology, our synthesis highlights areas ripe for progress, including a theoretical framework that incorporates host dynamics, spatial structuring and evolutionary processes, as well as the data needed to test the predictions of such a model. Our synthesis points the way for this framework and demonstrates that a deeper understanding of pathogen community dynamics will emerge from approaches working at the interface of disease and community ecology. © 2015 John Wiley & Sons Ltd/CNRS.

Evaluating Sustainability of Cropland Use in Yuanzhou County of the Loess Plateau, China Using an Emergy-Based Ecological Footprint

PubMed Central

Bai, Xiaomei; Wen, Zhongming; An, Shaoshan; Li, Bicheng

2015-01-01

Evaluating the sustainability of cropland use is essential for guaranteeing a secure food supply and accomplishing agriculture sustainable development. This study was conducted in the ecologically vulnerable Loess Plateau region of China to evaluate the sustainability of cropland use based on an ecological footprint model that integrates emergy analysis. One modified method proposed in 2005 is known as the emergetic ecological footprint (EEF). We enhanced the method by accounting for both the surface soil energy in the carrying capacity calculation and the net topsoil loss for human consumption in the EF calculation. This paper evaluates whether the cropland of the study area was overloaded or sustainably managed during the period from 1981 to 2009. Toward this end, the final results obtained from EEF were compared to conventional EF and previous methods. The results showed that the cropland of Yuanzhou County has not been used sustainably since 1983, and the conventional EF analysis provided similar results. In contrast, a deficit did not appear during this time period when previous calculation methods of others were used. Additionally, the ecological sustainable index (ESI) from three models indicated that the recently used cropland system is unlikely to be unsustainable. PMID:25738289

Ecological Interventionist Causal Models in Psychosis: Targeting Psychological Mechanisms in Daily Life

PubMed Central

Reininghaus, Ulrich; Depp, Colin A.; Myin-Germeys, Inez

2016-01-01

Integrated models of psychotic disorders have posited a number of putative psychological mechanisms that may contribute to the development of psychotic symptoms, but it is only recently that a modest amount of experience sampling research has provided evidence on their role in daily life, outside the research laboratory. A number of methodological challenges remain in evaluating specificity of potential causal links between a given psychological mechanism and psychosis outcomes in a systematic fashion, capitalizing on longitudinal data to investigate temporal ordering. In this article, we argue for testing ecological interventionist causal models that draw on real world and real-time delivered, ecological momentary interventions for generating evidence on several causal criteria (association, time order, and direction/sole plausibility) under real-world conditions, while maximizing generalizability to social contexts and experiences in heterogeneous populations. Specifically, this approach tests whether ecological momentary interventions can (1) modify a putative mechanism and (2) produce changes in the mechanism that lead to sustainable changes in intended psychosis outcomes in individuals’ daily lives. Future research using this approach will provide translational evidence on the active ingredients of mobile health and in-person interventions that promote sustained effectiveness of ecological momentary interventions and, thereby, contribute to ongoing efforts that seek to enhance effectiveness of psychological interventions under real-world conditions. PMID:26707864

Community-level demographic consequences of urbanization: an ecological network approach.

PubMed

Rodewald, Amanda D; Rohr, Rudolf P; Fortuna, Miguel A; Bascompte, Jordi

2014-11-01

Ecological networks are known to influence ecosystem attributes, but we poorly understand how interspecific network structure affect population demography of multiple species, particularly for vertebrates. Establishing the link between network structure and demography is at the crux of being able to use networks to understand population dynamics and to inform conservation. We addressed the critical but unanswered question, does network structure explain demographic consequences of urbanization? We studied 141 ecological networks representing interactions between plants and nesting birds in forests across an urbanization gradient in Ohio, USA, from 2001 to 2011. Nest predators were identified by video-recording nests and surveyed from 2004 to 2011. As landscapes urbanized, bird-plant networks were more nested, less compartmentalized and dominated by strong interactions between a few species (i.e. low evenness). Evenness of interaction strengths promoted avian nest survival, and evenness explained demography better than urbanization, level of invasion, numbers of predators or other qualitative network metrics. Highly uneven networks had approximately half the nesting success as the most even networks. Thus, nest survival reflected how urbanization altered species interactions, particularly with respect to how nest placement affected search efficiency of predators. The demographic effects of urbanization were not direct, but were filtered through bird-plant networks. This study illustrates how network structure can influence demography at the community level and further, that knowledge of species interactions and a network approach may be requisite to understanding demographic responses to environmental change. © 2014 The Authors. Journal of Animal Ecology © 2014 British Ecological Society.

Spatial and ecological population genetic structures within two island-endemic Aeonium species of different niche width.

PubMed

Harter, David E V; Thiv, Mike; Weig, Alfons; Jentsch, Anke; Beierkuhnlein, Carl

2015-10-01

The Crassulacean genus Aeonium is a well-known example for plant species radiation on oceanic archipelagos. However, while allopatric speciation among islands is documented for this genus, the role of intra-island speciation due to population divergence by topographical isolation or ecological heterogeneity has not yet been addressed. The aim of this study was to investigate intraspecific genetic structures and to identify spatial and ecological drivers of genetic population differentiation on the island scale. We analyzed inter simple sequence repeat variation within two island-endemic Aeonium species of La Palma: one widespread generalist that covers a large variety of different habitat types (Ae. davidbramwellii) and one narrow ecological specialist (Ae. nobile), in order to assess evolutionary potentials on this island. Gene pool differentiation and genetic diversity patterns were associated with major landscape structures in both species, with phylogeographic implications. However, overall levels of genetic differentiation were low. For the generalist species, outlier loci detection and loci-environment correlation approaches indicated moderate signatures of divergent selection pressures linked to temperature and precipitation variables, while the specialist species missed such patterns. Our data point to incipient differentiation among populations, emphasizing that ecological heterogeneity and topographical structuring within the small scales of an island can foster evolutionary processes. Very likely, such processes have contributed to the radiation of Aeonium on the Canary Islands. There is also support for different evolutionary mechanisms between generalist and specialist species.

Linking hydro-morphology with invertebrate ecology in diverse morphological units of a large river-floodplain system

NASA Astrophysics Data System (ADS)

Blettler, Martín. C. M.; Amsler, Mario L.; Eberle, Eliana G.; Szupiany, Ricardo; Latosinski, Francisco G.; Abrial, Elie; Oberholster, Paul J.; Espinola, Luis A.; Paira, Aldo; Poza, Ailen; Rodrigues Capítulo, Alberto

2016-12-01

Interdisciplinary research in the fields of ecohydrology and ecogeomorphology is becoming increasingly important as a way to understand how biological and physical processes interact with each other in river systems. The objectives of the current study were 1) to determine changes in invertebrate community due to hydrological stages, 2) to link local physical features [flow configuration, sediment composition and morphological feature) with the ecological structure between and within dissimilar morphological units (meander and confluence), and 3) to determine the existence and the origin of bed hydro-geomorphic patches, determining their ecological structure. Results were discussed in the frame of prevailing ecological models and concepts. The study site extends over a floodplain area of the large Paraná River (Argentina), including minor and major secondary channels as well as the main channel. Overall results suggested that hydrodynamics was the driving force determining distribution patterns of benthic assemblages in the floodplain. However, while the invertebrates living in minor secondary channels seem to benefit from flooding, this hydrological phase had the opposite effect on organisms from the main and major secondary channels. We also found a clear linkage between physical features and invertebrate ecology, which caused a dissimilar fauna structure between and within the meander and the confluence. Furthermore, several sandy-patches were recorded in the confluence. These patches were colonized by the particular benthic assemblage recorded in the main channel, supported the view of rivers as patchy discontinua, under uncertain ecological equilibrium.

Ecological and meteorological drought monitoring in East Asia

NASA Astrophysics Data System (ADS)

Kim, J. B.; Um, M. J.; Kim, Y.; Chae, Y.

2016-12-01

This study aims to how well the ecological drought index can capture the drought status in the East Asia. We estimated the drought severe index (DSI), which uses the evapotranspiration, potential evapotranspiration and the normalized difference vegetation index (NDVI), suggested by Mu et al. (2013) to define the ecological drought. In addition, the meteorological drought index, which is standardized precipitation and evapotranspiration index (SPEI), are estimated and compared to the DSI. The satellite data by moderate resolution imaging spectroradiometer (MODIS) and advanced very-high-resolution radiometer (AVHRR) are used to analyze the DSI and the monthly precipitation and temperature data in the climate research unit (CRU) are applied to estimate the SPEI for 2000-2013 in the East Asia. We conducted the statistical analyses to investigate the drought characteristics of the ecological and meteorological drought indices (i.e. the DSI and SPEI, respectively) and then compared those characteristics drought indices depending on the drought status. We found the DSI did not well captured the drought status when the categories originally suggested by Mu et al. (2013) are applied to divide the drought status in the study area. Consequently, the modified categories for the DSI in this study is suggested and then applied to define the drought status. The modified categories in this study show the great improvement to capture the drought status in the East Asia even though the results cannot be acquired around Taklamakan desert due to the lack of the satellite data. These results illustrate the ecological drought index, such as the DSI, can be applied for the monitoring of the drought in the East Asia and then can give the detailed information of drought status because the satellite data have the relatively high spatial resolutions compared to the observations such as the CRU data. Reference Mu Q, Zhao M, Kimball JS, McDowell NG, Running SW (2013) A remotely sensed global terrestrial drought severity index. Bulletin of the American Meteorological Society 94(1): 83-98. Acknowledgement This study was supported by the Korea Meteorological Administration R&D Program under Grant KMIPA 2015-6180. Corresponding Author: yeonjoo.kim@yonsei.ac.kr

Southern Great Plains Rapid Ecoregional Assessment: pre-assessment report

USGS Publications Warehouse

Assal, Timothy J.; Melcher, Cynthia P.; Carr, Natasha B.

2015-01-01

An overview on the ecology and management issues for each Conservation Element is provided, including distribution and ecology, landscape structure and dynamics, and associated species of management concern affiliated with each Conservation Element. For each Conservation Element, effects of the Change Agents are described. An overview of potential key ecological attributes and potential Change Agents are summarized by conceptual models and tables. The tables provide an organizational framework and background information for evaluating the key ecological attributes and Change Agents in Phase II.

Relation between Family Literacy Practices and Children's Literacy Development: Exploring the Link between Home and School

ERIC Educational Resources Information Center

McMurray, Jaclyn Roverud

2012-01-01

The purpose of this study was to examine the relation between family literacy practices and children's early literacy development. Drawing from a developmental-ecological framework, this study modified existing surveys (e.g., Family Involvement Questionnaire, a.k.a. FIQ, by Fantuzzo, Tighe, & Childs, 2000) to develop the "Family…

The Unique Challenges of Conserving Large Old Trees.

PubMed

Lindenmayer, David B; Laurance, William F

2016-06-01

Large old trees play numerous critical ecological roles. They are susceptible to a plethora of interacting threats, in part because the attributes that confer a competitive advantage in intact ecosystems make them maladapted to rapidly changing, human-modified environments. Conserving large old trees will require surmounting a number of unresolved challenges. Copyright © 2016 Elsevier Ltd. All rights reserved.

Development and Validation of a Modified Multiple Errands Test for Adults with Intellectual Disabilities

ERIC Educational Resources Information Center

Steverson, Tom; Adlam, Anna-Lynne R.; Langdon, Peter E.

2017-01-01

Background: The aims of the current study were to adapt a version of the MET for people with intellectual disabilities and assess its ecological and construct validity. Material and Methods: Using a correlational design, 40 participants with intellectual disabilities were invited to complete a battery of neuropsychological assessments and the…

Social infrastructure to integrate science and practice: the experience of the Long Tom Watershed Council

Treesearch

Rebecca L. Flitcroft; Dana C. Dedrick; Courtland L. Smith; Cynthia A. Thieman; John P. Bolte

2009-01-01

Ecological problem solving requires a flexible social infrastructure that can incorporate scientific insights and adapt to changing conditions. As applied to watershed management, social infrastructure includes mechanisms to design, carry out, evaluate, and modify plans for resource protection or restoration. Efforts to apply the best science will not bring anticipated...

Targeting physiological activities to modify the ecology and functionality of rumen and gastrointestinal ecosystems, prototypical anaerobic digester

USDA-ARS?s Scientific Manuscript database

The rumen microbial ecosystem is highly regarded for its ability to digest and transform low quality plant material into chemical forms of use by the host. However, less than 35% of the dietary energy consumed by the ruminant is conserved by the host. Methane production within the rumen contribute...

On Nature, Christianity and Deep Ecology--A Response to W. S. Helton and N. D. Helton

ERIC Educational Resources Information Center

Marangudakis, Manussos

2008-01-01

Establishing factually-based public support for the intrinsic value of nature, vis-a-vis a "domineering" or "stewardship" relation with the natural environment, necessitates the prior theoretical and methodological establishment of the above normative distinction. In this reply I argue that the Modified New Environmental Paradigm used by Helton…

Modeling the ecological trap hypothesis: a habitat and demographic analysis for migrant songbirds

Treesearch

Therese M. Donovan; Frank R, III Thompson

2001-01-01

Most species occupy both high- and low-quality habitats throughout their ranges. As habitats become modified through anthropogenic change, low-quality habitat may become a more dominant component of the landscape for some species. To conserve species, information on how to assess habitat quality and guidelines for maintaining or eliminating low-quality habitats are...

Ecological risk assessment to support fuels treatment project decisions

Treesearch

Jay O' Laughlin

2010-01-01

Risk is a combined statement of the probability that something of value will be damaged and some measure of the damage’s adverse effect. Wildfires burning in the uncharacteristic fuel conditions now typical throughout the Western United States can damage ecosystems and adversely affect environmental conditions. Wildfire behavior can be modified by prefire fuel...

Quantifying the multi-scale response of avifauna to prescribed fire experiments in the southwest United States

Treesearch

Brett G. Dickson; Barry R. Noon; Curtis H. Flather; Stephanie Jentsch; William M. Block

2009-01-01

Landscape-scale disturbance events, including ecological restoration and fuel reduction activities, can modify habitat and affect relationships between species and their environment. To reduce the risk of uncharacteristic stand-replacing fires in the southwestern United States, land managers are implementing restoration and fuels treatments (e.g., mechanical thinning,...

Alaskan Salmon and Gen R: Hunting, Fishing to Cultivate Ecological Mindfulness

ERIC Educational Resources Information Center

Mueller, Michael P.

2015-01-01

Can mining and fisheries co-exist in Bristol Bay, Alaska? To delve into this interesting tension, I expand on Clay Pierce's (this special issue) thoughtful analysis of genetically modified salmon and AquaBounty Technologies, where he explores actor-network theory in relation to scientific literacy and schooling. Further, my essay explores the idea…

The Water Framework Directive: total environment or political compromise?

PubMed

Moss, Brian

2008-08-01

The European Water Framework Directive (2000/60/EC) is potentially ground-breaking legislation. It seeks to bring about improvement of aquatic habitats in Europe to 'good ecological status', defined as slightly different from 'high ecological status', with no or minimal human impact. The characteristics of pristine ecological status include nutrient parsimony, a defined characteristic structure of the system (including geomorphological structure and hydrology, biological and food web structure) and the connectivity and extent of the system that are essential for resilience to change. This modern ecological understanding is being ignored by government agencies charged with enacting the Directive. Schemes are being devised that measure secondary characteristics of habitats using approaches drawn from traditional water quality management. Typologies, indicated by the Directive to give a geographical basis within which to determine ecological status, are also being corrupted with different typologies used for different determinands. The ecological reality of reasonably distinctive, integrated systems (an erosive upland river versus a floodplain system, for example) is being avoided. Emphasis is being placed on precision of measurement of specific determinands rather than accuracy in what is being measured and proposed schemes are complex and expensive when accurate assessment could be carried out much more cheaply. Many are also likely to become redundant as effects of climate change take hold. The current approach will lead to some improvement in water quality but not to the fundamental change in ecological quality intended by the Directive and has partly been encouraged by lack of definition and contradictions within the Directive itself. Documented details currently available from the UK agencies are used to illustrate how the intentions of the Directive are being undermined for ostensibly political convenience through processes of redefinition and limitation of characteristics measured. There appears to be a parallel concern among official and non-governmental European bodies.

Feminist ecology: Doing, undoing, and redoing gender in science

PubMed Central

Teller, Amy S.; Porcelli, Apollonya M.

2017-01-01

Women continue to be underrepresented in STEM fields and also are more likely to leave academic careers than men. While much existing sociological research on gender in science focuses on structures, institutions, and policies, we take a cultural and phenomenological approach to the question. We focus on the interaction between structural and micro-sociological forces that uphold existing gender inequalities and drive new forms of inequality within the discipline of ecology by tracing the experience of female graduate students. Ecology in the United States and elsewhere is currently undergoing three shifts, well documented by previous studies—more female scientists, interdisciplinary work, and research in human-altered landscapes—that comprise a transition to what we call “feminist ecology.” We ask whether these disciplinary-level shifts in ecology are accompanied by renegotiations in the way ecologists “do gender” as they work. In this paper we argue that despite structural changes toward a feminist ecology, gender inequalities are not eliminated. Our data collected using ethnographic and autoethnographic methods during ecological fieldwork in the Northeastern United States, show that gender inequality persists through daily interactions, shaping the way that fieldwork is conducted and bodies are policed. We provide additional evidence of the way that ecologists and non-ecologists interact during fieldwork, highlighting the embeddedness of scientific disciplines within larger societal forces. Thus, the question of women in science cannot be understood strictly from within the bounds of science but extends to gender relations in society at large. We hope that this study can serve as a teaching tool for university efforts to increase the success, not just the prevalence, of women in science, and facilitate productive interdisciplinary research across disciplines. PMID:28989594

Carbon mass balance and microbial ecology in a laboratory scale reactor achieving simultaneous sludge reduction and nutrient removal.

PubMed

Huang, Pei; Li, Liang; Kotay, Shireen Meher; Goel, Ramesh

2014-04-15

Solids reduction in activated sludge processes (ASP) at source using process manipulation has been researched widely over the last two-decades. However, the absence of nutrient removal component, lack of understanding on the organic carbon, and limited information on key microbial community in solids minimizing ASP preclude the widespread acceptance of sludge minimizing processes. In this manuscript, we report simultaneous solids reduction through anaerobiosis along with nitrogen and phosphorus removals. The manuscript also reports carbon mass balance using stable isotope of carbon, microbial ecology of nitrifiers and polyphosphate accumulating organisms (PAOs). Two laboratory scale reactors were operated in anaerobic-aerobic-anoxic (A(2)O) mode. One reactor was run in the standard mode (hereafter called the control-SBR) simulating conventional A(2)O type of activated sludge process and the second reactor was run in the sludge minimizing mode (called the modified-SBR). Unlike other research efforts where the sludge minimizing reactor was maintained at nearly infinite solids retention time (SRT). To sustain the efficient nutrient removal, the modified-SBR in this research was operated at a very small solids yield rather than at infinite SRT. Both reactors showed consistent NH3-N, phosphorus and COD removals over a period of 263 days. Both reactors also showed active denitrification during the anoxic phase even if there was no organic carbon source available during this phase, suggesting the presence of denitrifying PAOs (DNPAOs). The observed solids yield in the modified-SBR was 60% less than the observed solids yield in the control-SBR. Specific oxygen uptake rate (SOUR) for the modified-SBR was almost 44% more than the control-SBR under identical feeding conditions, but was nearly the same for both reactors under fasting conditions. The modified-SBR showed greater diversity of ammonia oxidizing bacteria and PAOs compared to the control-SBR. The diversity of PAOs in the modified-SBR was even more interesting in which case novel clades of Candidatus Accumulibacter phosphatis (CAP), an uncultured but widely found PAOs, were found. Copyright © 2014 Elsevier Ltd. All rights reserved.

Policy-Making Structures and Their Biases Towards Political Economy and Ecology.

ERIC Educational Resources Information Center

Lauber, Volkmar

The author suggests that the ecology movement in Western Europe has reached the limits of reactive politics and cannot achieve more unless it adopts a different strategy. Surveys and referenda show that the public has an overwhelmingly good opinion of the ecology movement but that few will vote on it in elections. Thus, the movement has had little…

Isolation by environmental distance in mobile marine species: molecular ecology of franciscana dolphins at their southern range.

PubMed

Mendez, Martin; Rosenbaum, Howard C; Subramaniam, Ajit; Yackulic, Charles; Bordino, Pablo

2010-06-01

The assessment of population structure is a valuable tool for studying the ecology of endangered species and drafting conservation strategies. As we enhance our understanding about the structuring of natural populations, it becomes important that we also understand the processes behind these patterns. However, there are few rigorous assessments of the influence of environmental factors on genetic patterns in mobile marine species. Given their dispersal capabilities and localized habitat preferences, coastal cetaceans are adequate study species for evaluating environmental effects on marine population structure. The franciscana dolphin, a rare coastal cetacean endemic to the Western South Atlantic, was studied to examine these issues. We analysed genetic data from the mitochondrial DNA and 12 microsatellite markers for 275 franciscana samples utilizing frequency-based, maximum-likelihood and Bayesian algorithms to assess population structure and migration patterns. This information was combined with 10 years of remote sensing environmental data (chlorophyll concentration, water turbidity and surface temperature). Our analyses show the occurrence of genetically isolated populations within Argentina, in areas that are environmentally distinct. Combined evidence of genetic and environmental structure suggests that isolation by distance and a process here termed isolation by environmental distance can explain the observed correlations. Our approach elucidated important ecological and conservation aspects of franciscana dolphins, and has the potential to increase our understanding of ecological processes influencing genetic patterns in other marine species.

An experimental test of a fundamental food web motif.

PubMed

Rip, Jason M K; McCann, Kevin S; Lynn, Denis H; Fawcett, Sonia

2010-06-07

Large-scale changes to the world's ecosystem are resulting in the deterioration of biostructure-the complex web of species interactions that make up ecological communities. A difficult, yet crucial task is to identify food web structures, or food web motifs, that are the building blocks of this baroque network of interactions. Once identified, these food web motifs can then be examined through experiments and theory to provide mechanistic explanations for how structure governs ecosystem stability. Here, we synthesize recent ecological research to show that generalist consumers coupling resources with different interaction strengths, is one such motif. This motif amazingly occurs across an enormous range of spatial scales, and so acts to distribute coupled weak and strong interactions throughout food webs. We then perform an experiment that illustrates the importance of this motif to ecological stability. We find that weak interactions coupled to strong interactions by generalist consumers dampen strong interaction strengths and increase community stability. This study takes a critical step by isolating a common food web motif and through clear, experimental manipulation, identifies the fundamental stabilizing consequences of this structure for ecological communities.

[Impacts of genetically modified soybean leaf residues on Folsomia candida.

PubMed

Zhou, Lin; Wang, Bai Feng; Liu, Xin Ying; Jiang, Ying; Wang, Da Ming; Feng, Shu Dan; Song, Xin Yuan

2016-09-01

When the genetically modified soybean is planted in the field, the expression product of exogenous gene could be exposed in the soil ecosystem and bring potential risk to the soil fauna, with the form of leaves and other debris. A few of genetically modified soybeans developed by China independently were used in our study as materials. They were Phytophthora-resistant soybean harboring hrpZm gene (B4J8049), leaf-feeding insect-resistant soybean harboring Cry1C gene (A2A8001) and Leguminivora glycinivorella-resistant soybean harboring Cry1Iem gene (C802). By feeding Folsomia candida with the three genetically modified soybeans for continuous 60 days, the surviving rate, reproductive rate and changes on the body length of F. candida were studied. The results showed that all the three genetically modified soybeans of B4J8049, A2A8001 and C802 had no significant adverse effects on the growth of F. candida, as an environmental indicator organism. It was initially inferred that they were environmentally safe under short-term exposure, which provided basic data of ecological safety for their wide cultivation.

Molecular ecological network analyses.

PubMed

Deng, Ye; Jiang, Yi-Huei; Yang, Yunfeng; He, Zhili; Luo, Feng; Zhou, Jizhong

2012-05-30

Understanding the interaction among different species within a community and their responses to environmental changes is a central goal in ecology. However, defining the network structure in a microbial community is very challenging due to their extremely high diversity and as-yet uncultivated status. Although recent advance of metagenomic technologies, such as high throughout sequencing and functional gene arrays, provide revolutionary tools for analyzing microbial community structure, it is still difficult to examine network interactions in a microbial community based on high-throughput metagenomics data. Here, we describe a novel mathematical and bioinformatics framework to construct ecological association networks named molecular ecological networks (MENs) through Random Matrix Theory (RMT)-based methods. Compared to other network construction methods, this approach is remarkable in that the network is automatically defined and robust to noise, thus providing excellent solutions to several common issues associated with high-throughput metagenomics data. We applied it to determine the network structure of microbial communities subjected to long-term experimental warming based on pyrosequencing data of 16 S rRNA genes. We showed that the constructed MENs under both warming and unwarming conditions exhibited topological features of scale free, small world and modularity, which were consistent with previously described molecular ecological networks. Eigengene analysis indicated that the eigengenes represented the module profiles relatively well. In consistency with many other studies, several major environmental traits including temperature and soil pH were found to be important in determining network interactions in the microbial communities examined. To facilitate its application by the scientific community, all these methods and statistical tools have been integrated into a comprehensive Molecular Ecological Network Analysis Pipeline (MENAP), which is open-accessible now (http://ieg2.ou.edu/MENA). The RMT-based molecular ecological network analysis provides powerful tools to elucidate network interactions in microbial communities and their responses to environmental changes, which are fundamentally important for research in microbial ecology and environmental microbiology.

Gene-Culture Coevolution in a Social Cetacean: Integrating Acoustic and Genetic Data to Understand Population Structure in the Short-Finned Pilot Whale (Globicephala macrorhynchus)

NASA Astrophysics Data System (ADS)

Van Cise, Amy

The evolutionary ecology of a species is driven by a combination of random events, ecological and environmental mechanisms, and social behavior. Gene-culture coevolutionary theory attempts to understand the evolutionary trajectory of a species by examining the interactions between these potential drivers. Further, our choice of data type will affect the patterns we observe, therefore by integrating several types of data we achieve a holistic understanding of the various aspects of evolutionary ecology within a species. In order to understand population structure in short-finned pilot whales, I use a combination of genetic and acoustic data to examine structure on evolutionary (genetic) and cultural (acoustic) timescales. I first examine structure among geographic populations in the Pacific Ocean. Using genetic sequences from the mitochondrial control region, I show that two genetically and morphologically distinct types of short-finned pilot whale, described off the coast of Japan, have non-overlapping distributions throughout their range in the Pacific Ocean. Analysis of the acoustic features of their social calls indicates that they are acoustically differentiated, possibly due to limited communication between the two types. This evidence supports the hypothesis that the two types may be separate species or subspecies. Next, I examine structure among island communities and social groups within the Hawaiian Island population of short-finned pilot whales. Using a combination of mitochondrial and nuclear DNA, I showed that the hierarchical social structure in Hawaiian pilot whales is driven by genetic relatedness; individuals remain in groups with their immediate family members, and preferentially associate with relatives. Similarly, social structure affects genetic differentiation, likely by restricting access to mates. Acoustic differentiation among social groups indicates that social structure may also restrict the flow of cultural information, such as vocal repertoire or dialect. The qualitative correlation between social structure, cultural information transfer, and genetic structure suggest that gene-culture coevolution may be an important mechanism to the evolutionary ecology of short-finned pilot whales. Further research may reveal a similar structure in the transmission of ecological behaviors, such as diet preference, habitat use, or movements. The results of this research underscore the applicability of gene-culture coevolutionary theory to non-human taxa.

Streamflow characteristics and benthic invertebrate assemblages in streams across the western United States

USGS Publications Warehouse

Brasher, Anne M.D.; Konrad, Chris P.; May, Jason T.; Edmiston, C. Scott; Close, Rebecca N.

2010-01-01

Hydrographic characteristics of streamflow, such as high-flow pulses, base flow (background discharge between floods), extreme low flows, and floods, significantly influence aquatic organisms. Streamflow can be described in terms of magnitude, timing, duration, frequency, and variation (hydrologic regime). These characteristics have broad effects on ecosystem productivity, habitat structure, and ultimately on resident fish, invertebrate, and algae communities. Increasing human use of limited water resources has modified hydrologic regimes worldwide. Identifying the most ecologically significant hydrographic characteristics would facilitate the development of water-management strategies.Benthic invertebrates include insects, mollusks (snails and clams), worms, and crustaceans (shrimp) that live on the streambed. Invertebrates play an important role in the food web, consuming other invertebrates and algae and being consumed by fish and birds. Hydrologic alteration associated with land and water use can change the natural hydrologic regime and may affect benthic invertebrate assemblage composition and structure through changes in density of invertebrates or taxa richness (number of different species).This study examined associations between the hydrologic regime and characteristics of benthic invertebrate assemblages across the western United States and developed tools to identify streamflow characteristics that are likely to affect benthic invertebrate assemblages.

Ontogeny of plants under various gravity condition

NASA Astrophysics Data System (ADS)

Laurinavičius, R.; Švegždienṡ, D.; Raklevičienė, D.; Kenstavičienė, P.

2001-01-01

The results of experiments performed under conditions of microgravity (MG) or under its simulation on the horizontal clinostat (HC) with the callus, seedlings of various species and embryogenic structures have revealed a definite role of gravity as an ecological factor in the processes of cytomorphogenesis, growth, and development. The transformation of differentiated somatic cells of arabidopsis seed into undifferentiated callus was not inhibited under MG, though modifications of the whole callus morphology and of mean cell and nucleus size were observed. The morphogenesis of polar structures such as root-hair bearing cells of Lactuca primary root has been shown to be modified in the course of differentiation under mass acceleration diminished below 0.1 g. Seed germination and seedling morphogenesis under MG follow their normal course, but a significant stimulation of shoot growth with no effect on primary root growth has been determined. A successful in vitro regeneration of Nicotiana tabacum plantlets from leaf cells and subsequent formation of shoots and roots on a continuously rotating HC as well as the formation of viable seeds during seed-to-seed growth of Arabidopsis plants under MG have indicated that gravity plays but a limited role in the processes of embryogenesis and organogenesis.

Resilience of Alaska's Boreal Forest to Climatic Change

NASA Technical Reports Server (NTRS)

Chapin, F. S., III; McGuire, A. D.; Ruess, R. W.; Hollingsworth, T. N.; Mack, M. C.; Johnstone, J. F.; Kasischke, E. S.; Euskirchen, E. S.; Jones, J. B.; Jorgenson, M. T.;

Resilience of Alaska’s boreal forest to climatic change

USGS Publications Warehouse

Chapin, F.S.; McGuire, A. David; Ruess, Roger W.; Hollingsworth, Teresa N.; Mack, M.C.; Johnstone, J.F.; Kasischke, E.S.; Euskirchen, E.S.; Jones, J.B.; Jorgenson, M.T.; Kielland, K.; Kofinas, G.; Turetsky, M.R.; Yarie, J.; Lloyd, A.H.; Taylor, D.L.

2010-01-01

This paper assesses the resilience of Alaska’s boreal forest system to rapid climatic change. Recent warming is associated with reduced growth of dominant tree species, plant disease and insect outbreaks, warming and thawing of permafrost, drying of lakes, increased wildfire extent, increased postfire recruitment of deciduous trees, and reduced safety of hunters traveling on river ice. These changes have modified key structural features, feedbacks, and interactions in the boreal forest, including reduced effects of upland permafrost on regional hydrology, expansion of boreal forest into tundra, and amplification of climate warming because of reduced albedo (shorter winter season) and carbon release from wildfires. Other temperature-sensitive processes for which no trends have been detected include composition of plant and microbial communities, long-term landscape-scale change in carbon stocks, stream discharge, mammalian population dynamics, and river access and subsistence opportunities for rural indigenous communities. Projections of continued warming suggest that Alaska’s boreal forest will undergo significant functional and structural changes within the next few decades that are unprecedented in the last 6000 years. The impact of these social–ecological changes will depend in part on the extent of landscape reorganization between uplands and lowlands and on policies regulating subsistence opportunities for rural communities.

A long-term soil structure observatory for post-compaction soil structure evolution: design and initial soil structure recovery observations

NASA Astrophysics Data System (ADS)

Keller, Thomas; Colombi, Tino; Ruiz, Siul; Grahm, Lina; Reiser, René; Rek, Jan; Oberholzer, Hans-Rudolf; Schymanski, Stanislaus; Walter, Achim; Or, Dani

2016-04-01

Soil compaction due to agricultural vehicular traffic alters the geometrical arrangement of soil constituents, thereby modifying mechanical properties and pore spaces that affect a range of soil hydro-ecological functions. The ecological and economic costs of soil compaction are dependent on the immediate impact on soil functions during the compaction event, and a function of the recovery time. In contrast to a wealth of soil compaction information, mechanisms and rates of soil structure recovery remain largely unknown. A long-term (>10-yr) soil structure observatory (SSO) was established in 2014 on a loamy soil in Zurich, Switzerland, to quantify rates and mechanisms of structure recovery of compacted arable soil under different post-compaction management treatments. We implemented three initial compaction treatments (using a two-axle agricultural vehicle with 8 Mg wheel load): compaction of the entire plot area (i.e. track-by-track), compaction in wheel tracks, and no compaction. After compaction, we implemented four post-compaction soil management systems: bare soil (BS), permanent grass (PG), crop rotation without mechanical loosening (NT), and crop rotation under conventional tillage (CT). BS and PG provide insights into uninterrupted natural processes of soil structure regeneration under reduced (BS) and normal biological activity (PG). The two cropping systems (NT and CT) enable insights into soil structure recovery under common agricultural practices with minimal (NT) and conventional mechanical soil disturbance (CT). Observations include periodic sampling and measurements of soil physical properties, earthworm abundance, crop measures, electrical resistivity and ground penetrating radar imaging, and continuous monitoring of state variables - soil moisture, temperature, CO2 and O2 concentrations, redox potential and oxygen diffusion rates - for which a network of sensors was installed at various depths (0-1 m). Initial compaction increased soil bulk density to about half a metre, decreased gas and water transport functions (air permeability, gas diffusivity, saturated hydraulic conductivity), and increased mechanical impedance. Water infiltration at the soil surface was initially reduced by three orders of magnitude, but significantly recovered within a year. However, within the soil profile, recovery of transport properties is much smaller. Air permeability tended to recover more than gas diffusivity, suggesting that initial post-compaction recovery is initiated by new macropores (e.g. biopores). Tillage recovered topsoil bulk density but not topsoil transport functions. Compaction changed grass species composition in PG, and significantly reduced grass biomass in PG and crop yields in NT and CT.

Managing ecological drought and flood within a nature-based approach. Reality or illusion?

NASA Astrophysics Data System (ADS)

Halbac-Cotoara-Zamfir, Rares; Finger, David; Stolte, Jannes

2017-04-01

Water hazards events, emphasized by an improperly implemented water management, may lead to ecological degradation of ecosystems. Traditional water management has generally sought to dampen the natural variability of water flows in different types of ecosystems to attain steady and dependable water supplies for domestic and industrial uses, irrigation, navigation, and hydropower, and to moderate extreme water conditions such as floods and droughts. Ecological drought can be defined as a prolonged and widespread deficit in available water supplies — including changes in natural and managed hydrology — that create multiple stresses across ecosystems, becomes a critical concern among researchers being a phenomenon much more complex than the other types of drought and requesting a specific approach. The impact of drought on ecosystem services lead to the necessity of identifying and implementing eco-reclamation measures which can generate better ecological answers to droughts. Ecological flood is the type of flood analyzed in full consideration with ecological issues, in the analyze process being approached 4 key aspects: connectivity of water system, landscapes of river and lakes, mobility of water bodies, and safety of flood control. As a consequence, both ecological drought and ecological flood represents high challenges for ecological sustainable water management in the process of identifying structural and non-structural measures for covering human demands without causing affected ecosystems to degrade or simplify. An ecological flood and drought control system will combine both the needs of the ecosystems as well as and flood and drought control measures. The components ecosystems' natural flow regime defined by magnitude, frequency, duration and peak timing (high or low flows) interact to maintain the ecosystem productivity. This productivity can be impaired by altered flow regimes generally due to structural measures designed to control flooding. However, from an ecological perspective, floods are not disasters in the sense that human society typically views them. Considering all previous aspects, it is clear that events like floods and droughts can't be avoided, but the hydrological extremes related to these events can be sustainable managed using a series of actions based on two inter-connected approaches: prevention approach and post-event management approach. The main objective remains the necessity of limiting the consequences of water hazards on socio-economic sectors but also the need of quickly and sustainable recovering after an event like this. However, the question still remains valid: Ecological flood and ecological drought can be managed through a nature-based approach? This paper will focus on a theoretical analysis of these "ecological" hydro-meteorological events and will debate a possible nature-based approach for their sustainable management.

Ecological Challenges for Closed Systems

NASA Astrophysics Data System (ADS)

Nelson, Mark; Dempster, William; Allen, John P.

2012-07-01

Closed ecological systems are desirable for a number of purposes. In space life support systems, material closure allows precious life-supporting resources to be kept inside and recycled. Closure in small biospheric systems facilitates detailed measurement of global ecological processes and biogeochemical cycles. Closed testbeds facilitate research topics which require isolation from the outside (e.g. genetically modified organisms; radioisotopes) so their ecological interactions and fluxes can be studied separate from interactions with the outside environment. But to achieve and maintain closure entails solving complex ecological challenges. These challenges include being able to handle faster cycling rates and accentuated daily and seasonal fluxes of critical life elements such as carbon dioxide, oxygen, water, macro- and mico-nutrients. The problems of achieving sustainability in closed systems for life support include how to handle atmospheric dynamics including trace gases, producing a complete human diet and recycling nutrients and maintaining soil fertility, the sustaining of healthy air and water and preventing the loss of crucial elements from active circulation. In biospheric facilities the challenge is also to produce analogues to natural biomes and ecosystems, studying processes of self-organization and adaptation in systems that allow specification or determination of state variables and cycles which may be followed through all interactions from atmosphere to soils. Other challenges include the dynamics and genetics of small populations, the psychological challenges for small isolated human groups and measures and options which may be necessary to ensure long-term operation of closed ecological systems.

Key ecological challenges for closed systems facilities

NASA Astrophysics Data System (ADS)

Nelson, Mark; Dempster, William F.; Allen, John P.

2013-07-01

Closed ecological systems are desirable for a number of purposes. In space life support systems, material closure allows precious life-supporting resources to be kept inside and recycled. Closure in small biospheric systems facilitates detailed measurement of global ecological processes and biogeochemical cycles. Closed testbeds facilitate research topics which require isolation from the outside (e.g. genetically modified organisms; radioisotopes) so their ecological interactions and fluxes can be studied separate from interactions with the outside environment. But to achieve and maintain closure entails solving complex ecological challenges. These challenges include being able to handle faster cycling rates and accentuated daily and seasonal fluxes of critical life elements such as carbon dioxide, oxygen, water, macro- and mico-nutrients. The problems of achieving sustainability in closed systems for life support include how to handle atmospheric dynamics including trace gases, producing a complete human diet, recycling nutrients and maintaining soil fertility, the maintenance of healthy air and water and preventing the loss of critical elements from active circulation. In biospheric facilities, the challenge is also to produce analogues to natural biomes and ecosystems, studying processes of self-organization and adaptation in systems that allow specification or determination of state variables and cycles which may be followed through all interactions from atmosphere to soils. Other challenges include the dynamics and genetics of small populations, the psychological challenges for small isolated human groups and backup technologies and strategic options which may be necessary to ensure long-term operation of closed ecological systems.

Ecological Structure of Recent and Last Glacial Mammalian Faunas in Northern Eurasia: The Case of Altai-Sayan Refugium

PubMed Central

Pavelková Řičánková, Věra; Robovský, Jan; Riegert, Jan

2014-01-01

Pleistocene mammalian communities display unique features which differ from present-day faunas. The paleocommunities were characterized by the extraordinarily large body size of herbivores and predators and by their unique structure consisting of species now inhabiting geographically and ecologically distinct natural zones. These features were probably the result of the unique environmental conditions of ice age ecosystems. To analyze the ecological structure of Last Glacial and Recent mammal communities we classified the species into biome and trophic-size categories, using Principal Component analysis. We found a marked similarity in ecological structure between Recent eastern Altai-Sayan mammalian assemblages and comparable Pleistocene faunas. The composition of Last Glacial and Recent eastern Altai-Sayan assemblages were characterized by the occurrence of large herbivore and predator species associated with steppe, desert and alpine biomes. These three modern biomes harbor most of the surviving Pleistocene mammals. None of the analyzed Palearctic Last Glacial faunas showed affinity to the temperate forest, taiga, or tundra biome. The Eastern part of the Altai-Sayan region could be considered a refugium of the Last Glacial-like mammalian assemblages. Glacial fauna seems to persist up to present in those areas where the forest belt does not separate alpine vegetation from the steppes and deserts. PMID:24454791

Designing Industrial Networks Using Ecological Food Web Metrics.

PubMed

Layton, Astrid; Bras, Bert; Weissburg, Marc

2016-10-18

Biologically Inspired Design (biomimicry) and Industrial Ecology both look to natural systems to enhance the sustainability and performance of engineered products, systems and industries. Bioinspired design (BID) traditionally has focused on a unit operation and single product level. In contrast, this paper describes how principles of network organization derived from analysis of ecosystem properties can be applied to industrial system networks. Specifically, this paper examines the applicability of particular food web matrix properties as design rules for economically and biologically sustainable industrial networks, using an optimization model developed for a carpet recycling network. Carpet recycling network designs based on traditional cost and emissions based optimization are compared to designs obtained using optimizations based solely on ecological food web metrics. The analysis suggests that networks optimized using food web metrics also were superior from a traditional cost and emissions perspective; correlations between optimization using ecological metrics and traditional optimization ranged generally from 0.70 to 0.96, with flow-based metrics being superior to structural parameters. Four structural food parameters provided correlations nearly the same as that obtained using all structural parameters, but individual structural parameters provided much less satisfactory correlations. The analysis indicates that bioinspired design principles from ecosystems can lead to both environmentally and economically sustainable industrial resource networks, and represent guidelines for designing sustainable industry networks.

Into the black and back: the ecology of brain investment in Neotropical army ants (Formicidae: Dorylinae)

NASA Astrophysics Data System (ADS)

Bulova, S.; Purce, K.; Khodak, P.; Sulger, E.; O'Donnell, S.

2016-04-01

Shifts to new ecological settings can drive evolutionary changes in animal sensory systems and in the brain structures that process sensory information. We took advantage of the diverse habitat ecology of Neotropical army ants to test whether evolutionary transitions from below- to above-ground activity were associated with changes in brain structure. Our estimates of genus-typical frequencies of above-ground activity suggested a high degree of evolutionary plasticity in habitat use among Neotropical army ants. Brain structure consistently corresponded to degree of above-ground activity among genera and among species within genera. The most above-ground genera (and species) invested relatively more in visual processing brain tissues; the most subterranean species invested relatively less in central processing higher-brain centers (mushroom body calyces). These patterns suggest a strong role of sensory ecology (e.g., light levels) in selecting for army ant brain investment evolution and further suggest that the subterranean environment poses reduced cognitive challenges to workers. The highly above-ground active genus Eciton was exceptional in having relatively large brains and particularly large and structurally complex optic lobes. These patterns suggest that the transition to above-ground activity from ancestors that were largely subterranean for approximately 60 million years was followed by re-emergence of enhanced visual function in workers.

Asymmetric effects of native and exotic invasive shrubs on ecology of the West Nile virus vector Culex pipiens (Diptera: Culicidae).

PubMed

Gardner, Allison M; Allan, Brian F; Frisbie, Lauren A; Muturi, Ephantus J

2015-06-16

Exotic invasive plants alter the structure and function of native ecosystems and may influence the distribution and abundance of arthropod disease vectors by modifying habitat quality. This study investigated how invasive plants alter the ecology of Culex pipiens, an important vector of West Nile virus (WNV) in northeastern and midwestern regions of the United States. Field and laboratory experiments were conducted to test the hypothesis that three native leaf species (Rubus allegheniensis, blackberry; Sambucus canadensis, elderberry; and Amelanchier laevis, serviceberry), and three exotic invasive leaf species (Lonicera maackii, Amur honeysuckle; Elaeagnus umbellata, autumn olive; and Rosa multiflora, multiflora rose) alter Cx. pipiens oviposition site selection, emergence rates, development time, and adult body size. The relative abundance of seven bacterial phyla in infusions of the six leaf species also was determined using quantitative real-time polymerase chain reaction to test the hypothesis that variation in emergence, development, and oviposition site selection is correlated to differences in the diversity and abundance of bacteria associated with different leaf species, important determinants of nutrient quality and availability for mosquito larvae. Leaf detritus from invasive honeysuckle and autumn olive yielded significantly higher adult emergence rates compared to detritus from the remaining leaf species and honeysuckle alleviated the negative effects of intraspecific competition on adult emergence. Conversely, leaves of native blackberry acted as an ecological trap, generating high oviposition but low emergence rates. Variation in bacterial flora associated with different leaf species may explain this asymmetrical production of mosquitoes: emergence rates and oviposition rates were positively correlated to bacterial abundance and diversity, respectively. We conclude that the displacement of native understory plant species by certain invasive shrubs may increase production of Cx. pipiens with potential negative repercussions for human and wildlife health. These findings may be relevant to mosquito control and invasive plant management practices in the geographic range of Cx. pipiens. Further, our discovery of a previously unknown ecological trap for an important vector of WNV has the potential to lead to novel alternatives to conventional insecticides in mosquito control by exploiting the apparent "attract-kill" properties of this native plant species.

Development of the Hydrological-Ecological Integrated watershed Flow Model (HEIFLOW): an application to the Heihe River Basin

NASA Astrophysics Data System (ADS)

Tian, Y.; Zheng, Y.; Zheng, C.; Han, F., Sr.

2017-12-01

Physically based and fully-distributed integrated hydrological models (IHMs) can quantitatively depict hydrological processes, both surface and subsurface, with sufficient spatial and temporal details. However, the complexity involved in pre-processing data and setting up models seriously hindered the wider application of IHMs in scientific research and management practice. This study introduces our design and development of Visual HEIFLOW, hereafter referred to as VHF, a comprehensive graphical data processing and modeling system for integrated hydrological simulation. The current version of VHF has been structured to accommodate an IHM named HEIFLOW (Hydrological-Ecological Integrated watershed-scale FLOW model). HEIFLOW is a model being developed by the authors, which has all typical elements of physically based and fully-distributed IHMs. It is based on GSFLOW, a representative integrated surface water-groundwater model developed by USGS. HEIFLOW provides several ecological modules that enable to simulate growth cycle of general vegetation and special plants (maize and populus euphratica). VHF incorporates and streamlines all key steps of the integrated modeling, and accommodates all types of GIS data necessary to hydrological simulation. It provides a GIS-based data processing framework to prepare an IHM for simulations, and has functionalities to flexibly display and modify model features (e.g., model grids, streams, boundary conditions, observational sites, etc.) and their associated data. It enables visualization and various spatio-temporal analyses of all model inputs and outputs at different scales (i.e., computing unit, sub-basin, basin, or user-defined spatial extent). The above system features, as well as many others, can significantly reduce the difficulty and time cost of building and using a complex IHM. The case study in the Heihe River Basin demonstrated the applicability of VHF for large scale integrated SW-GW modeling. Visualization and spatial-temporal analysis of the modeling results by HEIFLOW greatly facilitates our understanding on the complicated hydrologic cycle and relationship among the hydrological and ecological variables in the study area, and provides insights into the regional water resources management.

Ecological assessment of a southeastern Brazil reservoir

EPA Science Inventory

Abstract: Reservoirs are artificial ecosystems with multiple functions having direct and indirect benefits to humans; however, they also cause ecological changes and influence the composition and structure of aquatic biota. Our objectives were to: (1) assess the environmen...

An ecological assessment of a bridge demolition.

DOT National Transportation Integrated Search

1975-01-01

Bridge demolition has long been known to mobilize large amounts of stream sediment in the immediate area of the structure. An ecological assessment in terms of stream macroinvertebrate samples and suspended solids measurements was made shortly before...

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.

The role of social and ecological processes in structuring animal populations: a case study from automated tracking of wild birds

PubMed Central

Farine, Damien R.; Firth, Josh A.; Aplin, Lucy M.; Crates, Ross A.; Culina, Antica; Garroway, Colin J.; Hinde, Camilla A.; Kidd, Lindall R.; Milligan, Nicole D.; Psorakis, Ioannis; Radersma, Reinder; Verhelst, Brecht; Voelkl, Bernhard; Sheldon, Ben C.

2015-01-01

Both social and ecological factors influence population process and structure, with resultant consequences for phenotypic selection on individuals. Understanding the scale and relative contribution of these two factors is thus a central aim in evolutionary ecology. In this study, we develop a framework using null models to identify the social and spatial patterns that contribute to phenotypic structure in a wild population of songbirds. We used automated technologies to track 1053 individuals that formed 73 737 groups from which we inferred a social network. Our framework identified that both social and spatial drivers contributed to assortment in the network. In particular, groups had a more even sex ratio than expected and exhibited a consistent age structure that suggested local association preferences, such as preferential attachment or avoidance. By contrast, recent immigrants were spatially partitioned from locally born individuals, suggesting differential dispersal strategies by phenotype. Our results highlight how different scales of social decision-making, ranging from post-natal dispersal settlement to fission–fusion dynamics, can interact to drive phenotypic structure in animal populations. PMID:26064644

The Correlation of Geo-Ecological Environment and Mountain Urban planning

NASA Astrophysics Data System (ADS)

Yang, Chun; Zeng, Wei

2018-01-01

As a special area with the complex geological structure, mountain city is more prone to geological disasters. Due to air pollution, ground subsidence, serious water pollution, earthquakes and floods geo-ecological environment problems have become increasingly serious, mountain urban planning is facing more severe challenges. Therefore, this article bases on the correlation research of geo-ecological environment and mountain urban planning, and re-examins mountain urban planning from the perspective of geo-ecological, coordinates the relationship between the human and nature by geo-ecological thinking, raises the questions which urban planning need to pay attention. And advocates creating an integrated system of geo-ecological and mountain urban planning, analysis the status and dynamics of present mountain urban planning.

Electron beam technology for modifying the functional properties of maize starch

NASA Astrophysics Data System (ADS)

Nemţanu, M. R.; Minea, R.; Kahraman, K.; Koksel, H.; Ng, P. K. W.; Popescu, M. I.; Mitru, E.

2007-09-01

Maize starch is a versatile biopolymer with a wide field of applications (e.g. foods, pharmaceutical products, adhesives, etc.). Nowadays there is a continuous and intensive search for new methods and techniques to modify its functional properties due to the fact that native form of starch may exhibit some disadvantages in certain applications. Radiation technology is frequently used to change the properties of different polymeric materials. Thus, the goal of the work is to discuss the application of accelerated electron beams on maize starch in the view of changing some of its functional properties. Maize starch has been irradiated with doses up to 52.15 kGy by using electron beam technology and the modifications of differential scanning calorimetry (DSC) and pasting characteristics, paste clarity, freezing and thawing stability as well as colorimetric characteristics have been investigated. The results of the study revealed that the measured properties can be modified by electron beam treatment and, therefore, this method can be an efficient and ecological alternative to obtain modified maize starch.

Floating Ocean Platform

DTIC Science & Technology

2003-08-15

floating structures create novel habitats for subtidal epibiota?, MARINE ECOLOGY -PROGRESS SERIES, 43-52 Mar. Ecol.- Prog. Ser., 2002 Vegueria, SFJ Godoy... ECOLOGICAL APPLICATIONS, 350-366 Ecol. Appl., 2000 Niedzwecki, JM van de Lindt, JW Gage, JH Teigen, PS, Design estimates of surface wave interaction with...The ecological effects beyond the offshore platform, Coastal Zone: Proceedings of the Symposium on Coastal and Ocean Management, v 2, n pt2, 1989, p

Operation and Maintence, Vermilion Harbor, Erie County, Ohio.

DTIC Science & Technology

1976-03-01

channel and structural maintenance activities at Vermilion Harbor. Although 6 ...- this alternative would eliminate temporary adverse ecological effects of...of dredging on water quality, aquatic ecology , and harbor recreation and related 4 businesses wbuld be reduced to a level commensurate with reduced...effects on aquatic ecology but would have long- term, beneficial effects on shoreline erosion and beach areas. There have been no specific requests from

Analysing ecological networks of species interactions.

PubMed

Delmas, Eva; Besson, Mathilde; Brice, Marie-Hélène; Burkle, Laura A; Dalla Riva, Giulio V; Fortin, Marie-Josée; Gravel, Dominique; Guimarães, Paulo R; Hembry, David H; Newman, Erica A; Olesen, Jens M; Pires, Mathias M; Yeakel, Justin D; Poisot, Timothée

2018-06-20

Network approaches to ecological questions have been increasingly used, particularly in recent decades. The abstraction of ecological systems - such as communities - through networks of interactions between their components indeed provides a way to summarize this information with single objects. The methodological framework derived from graph theory also provides numerous approaches and measures to analyze these objects and can offer new perspectives on established ecological theories as well as tools to address new challenges. However, prior to using these methods to test ecological hypotheses, it is necessary that we understand, adapt, and use them in ways that both allow us to deliver their full potential and account for their limitations. Here, we attempt to increase the accessibility of network approaches by providing a review of the tools that have been developed so far, with - what we believe to be - their appropriate uses and potential limitations. This is not an exhaustive review of all methods and metrics, but rather, an overview of tools that are robust, informative, and ecologically sound. After providing a brief presentation of species interaction networks and how to build them in order to summarize ecological information of different types, we then classify methods and metrics by the types of ecological questions that they can be used to answer from global to local scales, including methods for hypothesis testing and future perspectives. Specifically, we show how the organization of species interactions in a community yields different network structures (e.g., more or less dense, modular or nested), how different measures can be used to describe and quantify these emerging structures, and how to compare communities based on these differences in structures. Within networks, we illustrate metrics that can be used to describe and compare the functional and dynamic roles of species based on their position in the network and the organization of their interactions as well as associated new methods to test the significance of these results. Lastly, we describe potential fruitful avenues for new methodological developments to address novel ecological questions. © 2018 Cambridge Philosophical Society.

Methods for modifying monofilaments, bundles of monofilaments, and fibrous structural material

DOEpatents

Allen, Charles A.; Argyle, Mark D.; Fox, Robert V.; Ginosar, Daniel M.; Janikowski, Stuart K.; Miller, David L.; Propp, W. Alan; Toth, William J.

2002-12-17

The present invention is related to the modifying of substrates such as monofilaments, bundles of monofilaments, and fibrous structural material with a modifying agent. The modifying agent is suspended or dissolved in a supercritical fluid, near-critical fluid, superheated fluid, superheated liquid, or a liquified gas and is deposited by rapidly altering the pressure in a chamber to deposit the modifying material onto the substrate.

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

Systematic planning of disconnection to enhance conservation success in a modified world.

PubMed

Hermoso, Virgilio; Januchowski-Hartley, Stephanie R; Linke, Simon

2015-12-01

Maintaining spatial-temporal connectivity for conservation is necessary to allow the persistence of ecological processes and the biodiversity they sustain. However, conservation practice in human-modified environments can also benefit from prescribed disconnection through the implementation of barriers. Barriers, such as fences or dams, and buffer zones can be a cost-effective way of addressing threats caused by a globally connected world, such as the propagation of invasive species and diseases, creating refuge areas for native biodiversity and helping reduce economic losses caused by native wildlife or invasive species. Despite the global attention that disconnection has received, no clear framework exists to guide the allocation of barriers for conservation management. Here we propose that the implementation of barriers for conservation should be systematically planned, considering ecological trade-offs for multiple species (easing threats vs. interruption of ecosystem processes) and socio-economic cost-benefits (implementation cost vs. reduced human-wildlife conflicts), rather than using ad-hoc opportunistic criteria or accommodating conservation needs for individual species. Such a systematic approach is necessary to ensure both socially acceptable and ecologically effective use of disconnections as a conservation tool and ideally planned across different realms so co-benefits or trade-offs can be accounted for. However, any implementation of disconnection for conservation should be cautiously considered if uncertainty in effectiveness of the barrier and ecological impacts to other species are high. We also suggest the need for improved approaches to monitoring to learn from previous successes and failures. Our recommendations should guide the systematic evaluation and allocation of barriers to help enhance the value of this conservation tool in the face of increasing propagation of threats worldwide. However, new tools and collaborative frameworks across different realms are needed to help stakeholders make better informed decision. Copyright © 2015 Elsevier B.V. All rights reserved.

Evidence for environmental and ecological selection in a microbe with no geographic limits to gene flow.

PubMed

Whittaker, Kerry A; Rynearson, Tatiana A

2017-03-07

The ability for organisms to disperse throughout their environment is thought to strongly influence population structure and thus evolution of diversity within species. A decades-long debate surrounds processes that generate and support high microbial diversity, particularly in the ocean. The debate concerns whether diversification occurs primarily through geographic partitioning (where distance limits gene flow) or through environmental selection, and remains unresolved due to lack of empirical data. Here we show that gene flow in a diatom, an ecologically important eukaryotic microbe, is not limited by global-scale geographic distance. Instead, environmental and ecological selection likely play a more significant role than dispersal in generating and maintaining diversity. We detected significantly diverged populations ( F ST > 0.130) and discovered temporal genetic variability at a single site that was on par with spatial genetic variability observed over distances of 15,000 km. Relatedness among populations was decoupled from geographic distance across the global ocean and instead, correlated significantly with water temperature and whole-community chlorophyll a Correlations with temperature point to the importance of environmental selection in structuring populations. Correlations with whole-community chlorophyll a , a proxy for autotrophic biomass, suggest that ecological selection via interactions with other plankton may generate and maintain population genetic structure in marine microbes despite global-scale dispersal. Here, we provide empirical evidence for global gene flow in a marine eukaryotic microbe, suggesting that everything holds the potential to be everywhere, with environmental and ecological selection rather than geography or dispersal dictating the structure and evolution of diversity over space and time.

Genomic diversity is similar between Atlantic Forest restorations and natural remnants for the native tree Casearia sylvestris Sw.

PubMed

Gomes Viana, João Paulo; Bohrer Monteiro Siqueira, Marcos Vinícius; Araujo, Fabiano Lucas; Grando, Carolina; Sanae Sujii, Patricia; Silvestre, Ellida de Aguiar; Novello, Mariana; Pinheiro, José Baldin; Cavallari, Marcelo Mattos; Brancalion, Pedro H S; Rodrigues, Ricardo Ribeiro; Pereira de Souza, Anete; Catchen, Julian; Zucchi, Maria I

2018-01-01

The primary focus of tropical forest restoration has been the recovery of forest structure and tree taxonomic diversity, with limited attention given to genetic conservation. Populations reintroduced through restoration plantings may have low genetic diversity and be genetically structured due to founder effects and genetic drift, which limit the potential of restoration to recover ecologically resilient plant communities. Here, we studied the genetic diversity, genetic structure and differentiation using single nucleotide polymorphisms (SNP) markers between restored and natural populations of the native tree Casearia sylvestris in the Atlantic Forest of Brazil. We sampled leaves from approximately 24 adult individuals in each of the study sites: two restoration plantations (27 and 62 years old) and two forest remnants. We prepared and sequenced a genotyping-by-sequencing library, SNP markers were identified de novo using Stacks pipeline, and genetic parameters and structure analyses were then estimated for populations. The sequencing step was successful for 80 sampled individuals. Neutral genetic diversity was similar among restored and natural populations (AR = 1.72 ± 0.005; HO = 0.135 ± 0.005; HE = 0.167 ± 0.005; FIS = 0.16 ± 0.022), which were not genetically structured by population subdivision. In spite of this absence of genetic structure by population we found genetic structure within populations but even so there is not spatial genetic structure in any population studied. Less than 1% of the neutral alleles were exclusive to a population. In general, contrary to our expectations, restoration plantations were then effective for conserving tree genetic diversity in human-modified tropical landscapes. Furthermore, we demonstrate that genotyping-by-sequencing can be a useful tool in restoration genetics.

The ecological forecast horizon, and examples of its uses and determinants

PubMed Central

Petchey, Owen L; Pontarp, Mikael; Massie, Thomas M; Kéfi, Sonia; Ozgul, Arpat; Weilenmann, Maja; Palamara, Gian Marco; Altermatt, Florian; Matthews, Blake; Levine, Jonathan M; Childs, Dylan Z; McGill, Brian J; Schaepman, Michael E; Schmid, Bernhard; Spaak, Piet; Beckerman, Andrew P; Pennekamp, Frank; Pearse, Ian S; Vasseur, David

2015-01-01

Forecasts of ecological dynamics in changing environments are increasingly important, and are available for a plethora of variables, such as species abundance and distribution, community structure and ecosystem processes. There is, however, a general absence of knowledge about how far into the future, or other dimensions (space, temperature, phylogenetic distance), useful ecological forecasts can be made, and about how features of ecological systems relate to these distances. The ecological forecast horizon is the dimensional distance for which useful forecasts can be made. Five case studies illustrate the influence of various sources of uncertainty (e.g. parameter uncertainty, environmental variation, demographic stochasticity and evolution), level of ecological organisation (e.g. population or community), and organismal properties (e.g. body size or number of trophic links) on temporal, spatial and phylogenetic forecast horizons. Insights from these case studies demonstrate that the ecological forecast horizon is a flexible and powerful tool for researching and communicating ecological predictability. It also has potential for motivating and guiding agenda setting for ecological forecasting research and development. PMID:25960188

Mathematical Ecology Analysis of Geographical Distribution of Soybean-Nodulating Bradyrhizobia in Japan

PubMed Central

Saeki, Yuichi; Shiro, Sokichi; Tajima, Toshiyuki; Yamamoto, Akihiro; Sameshima-Saito, Reiko; Sato, Takashi; Yamakawa, Takeo

2013-01-01

We characterized the relationship between the genetic diversity of indigenous soybean-nodulating bradyrhizobia from weakly acidic soils in Japan and their geographical distribution in an ecological study of indigenous soybean rhizobia. We isolated bradyrhizobia from three kinds of Rj-genotype soybeans. Their genetic diversity and community structure were analyzed by PCR-RFLP analysis of the 16S–23S rRNA gene internal transcribed spacer (ITS) region with 11 Bradyrhizobium USDA strains as references. We used data from the present study and previous studies to carry out mathematical ecological analyses, multidimensional scaling analysis with the Bray-Curtis index, polar ordination analysis, and multiple regression analyses to characterize the relationship between soybean-nodulating bradyrhizobial community structures and their geographical distribution. The mathematical ecological approaches used in this study demonstrated the presence of ecological niches and suggested the geographical distribution of soybean-nodulating bradyrhizobia to be a function of latitude and the related climate, with clusters in the order Bj123, Bj110, Bj6, and Be76 from north to south in Japan. PMID:24240318

Mapping of Soil-Ecological Conditions of a Medium-Size Industrial City (Birobidzhan City, Jewish Autonomous Oblast, FarEast of Russia as an Example)

NASA Astrophysics Data System (ADS)

Kalmanova, V. B.; Matiushkina, L. A.

2018-01-01

The authors analyze soil relations with other elements of the city ecosystem (the position in the landscape, soil-forming rocks and lithology, vegetation and its state) to develop the legend and map of soils in the City of Birobidzhan (scale 1:25 000). The focus of study is the morphological structure of urban soils with different degree of disturbance of these relations under the impact of technical effects, economic and recreational activities of the city population. The soil cover structure is composed of four large ecological groups of soils: natural untransformed, natural with a disturbed surface, anthropogenic soils and technogenic surface formations. Using cartometry of the mapped soil contours the authors created the scheme of soil-ecological city zoning, which in a general way depicts the state of soil ecological functions in the city as well as identified zones of soils with preserved, partially and fully distured ecological functions and zones of local geochemical anomalies at the initial formation stage (environmental risk zones).

Phylogenetic overdispersion of plant species in southern Brazilian savannas.

PubMed

Silva, I A; Batalha, M A

2009-08-01

Ecological communities are the result of not only present ecological processes, such as competition among species and environmental filtering, but also past and continuing evolutionary processes. Based on these assumptions, we may infer mechanisms of contemporary coexistence from the phylogenetic relationships of the species in a community. We studied the phylogenetic structure of plant communities in four cerrado sites, in southeastern Brazil. We calculated two raw phylogenetic distances among the species sampled. We estimated the phylogenetic structure by comparing the observed phylogenetic distances to the distribution of phylogenetic distances in null communities. We obtained null communities by randomizing the phylogenetic relationships of the regional pool of species. We found a phylogenetic overdispersion of the cerrado species. Phylogenetic overdispersion has several explanations, depending on the phylogenetic history of traits and contemporary ecological interactions. However, based on coexistence models between grasses and trees, density-dependent ecological forces, and the evolutionary history of the cerrado flora, we argue that the phylogenetic overdispersion of cerrado species is predominantly due to competitive interactions, herbivores and pathogen attacks, and ecological speciation. Future studies will need to include information on the phylogenetic history of plant traits.

Constraints imposed by pollinator behaviour on the ecology and evolution of plant mating systems.

PubMed

Devaux, C; Lepers, C; Porcher, E

2014-07-01

Most flowering plants rely on pollinators for their reproduction. Plant-pollinator interactions, although mutualistic, involve an inherent conflict of interest between both partners and may constrain plant mating systems at multiple levels: the immediate ecological plant selfing rates, their distribution in and contribution to pollination networks, and their evolution. Here, we review experimental evidence that pollinator behaviour influences plant selfing rates in pairs of interacting species, and that plants can modify pollinator behaviour through plastic and evolutionary changes in floral traits. We also examine how theoretical studies include pollinators, implicitly or explicitly, to investigate the role of their foraging behaviour in plant mating system evolution. In doing so, we call for more evolutionary models combining ecological and genetic factors, and additional experimental data, particularly to describe pollinator foraging behaviour. Finally, we show that recent developments in ecological network theory help clarify the impact of community-level interactions on plant selfing rates and their evolution and suggest new research avenues to expand the study of mating systems of animal-pollinated plant species to the level of the plant-pollinator networks. © 2014 The Authors. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

Chemical footprint method for improved communication of freshwater ecotoxicity impacts in the context of ecological limits.

PubMed

Bjørn, Anders; Diamond, Miriam; Birkved, Morten; Hauschild, Michael Zwicky

2014-11-18

The ecological footprint method has been successful in communicating environmental impacts of anthropogenic activities in the context of ecological limits. We introduce a chemical footprint method that expresses ecotoxicity impacts from anthropogenic chemical emissions as the dilution needed to avoid freshwater ecosystem damage. The indicator is based on USEtox characterization factors with a modified toxicity reference point. Chemical footprint results can be compared to the actual dilution capacity within the geographic vicinity receiving the emissions to estimate whether its ecological limit has been exceeded and hence whether emissions can be expected to be environmentally sustainable. The footprint method was illustrated using two case studies. The first was all inventoried emissions from European countries and selected metropolitan areas in 2004, which indicated that the dilution capacity was likely exceeded for most European countries and all landlocked metropolitan areas. The second case study indicated that peak application of pesticides alone was likely to exceed Denmark's freshwater dilution capacity in 1999-2011. The uncertainty assessment showed that better spatially differentiated fate factors would be useful and pointed out other major sources of uncertainty and some opportunities to reduce these.

Dynamic assessment of microbial ecology (DAME): a web app for interactive analysis and visualization of microbial sequencing data.

PubMed

Piccolo, Brian D; Wankhade, Umesh D; Chintapalli, Sree V; Bhattacharyya, Sudeepa; Chunqiao, Luo; Shankar, Kartik

2018-03-15

Dynamic assessment of microbial ecology (DAME) is a Shiny-based web application for interactive analysis and visualization of microbial sequencing data. DAME provides researchers not familiar with R programming the ability to access the most current R functions utilized for ecology and gene sequencing data analyses. Currently, DAME supports group comparisons of several ecological estimates of α-diversity and β-diversity, along with differential abundance analysis of individual taxa. Using the Shiny framework, the user has complete control of all aspects of the data analysis, including sample/experimental group selection and filtering, estimate selection, statistical methods and visualization parameters. Furthermore, graphical and tabular outputs are supported by R packages using D3.js and are fully interactive. DAME was implemented in R but can be modified by Hypertext Markup Language (HTML), Cascading Style Sheets (CSS), and JavaScript. It is freely available on the web at https://acnc-shinyapps.shinyapps.io/DAME/. Local installation and source code are available through Github (https://github.com/bdpiccolo/ACNC-DAME). Any system with R can launch DAME locally provided the shiny package is installed. bdpiccolo@uams.edu.

The movement ecology and dynamics of plant communities in fragmented landscapes

DOE PAGES

Damschen, Ellen I.; Brudvig, Lars A.; Haddad, Nick M.; ...

2008-12-05

A conceptual model of movement ecology has recently been advanced to explain all movement by considering the interaction of four elements: internal state, motion capacity, navigation capacities,and external factors. We modified this framework togenerate predictions for species richness dynamics of fragmented plant communities and tested them in experimental landscapes across a 7-year time series. We found that two external factors, dispersal vectors and habitat features, affected species colonization and recolonization in habitat fragments and their effects varied and depended on motion capacity. Bird-dispersed species richness showed connectivity effects that reached an asymptote over time, but no edge effects, whereas wind-dispersedmore » species richness showed steadily accumulating edge and connectivity effects, with no indication of an asymptote. Unassisted species also showed increasing differences caused by connectivity over time,whereas edges had no effect. Our limited use of proxies for movement ecology (e.g., dispersal mode as a proxy for motion capacity) resulted in moderate predictive power for communities and, in some cases, highlighted the importance of a more complete understanding of movement ecology for predicting how landscape conservation actions affect plant community dynamics.« less

The ecological and construct validity of a newly developed measure of executive function: the Virtual Library Task.

PubMed

Renison, Belinda; Ponsford, Jennie; Testa, Renee; Richardson, Barry; Brownfield, Kylie

2012-05-01

Virtual reality (VR) assessment paradigms have the potential to address the limited ecological validity of pen and paper measures of executive function (EF) and the pragmatic and reliability issues associated with functional measures. To investigate the ecological validity and construct validity of a newly developed VR measure of EF, the Virtual Library Task (VLT); a real life analogous task--the Real Library Task (RLT); and five neuropsychological measures of EF were administered to 30 patients with traumatic brain injury (TBI) and 30 healthy Controls. Significant others for each participant also completed the Dysexecutive Questionnaire (DEX), which is a behavioral rating scale of everyday EF. Performances on the VLT and the RLT were significantly positively correlated indicating that VR performance is similar to real world performance. The TBI group performed significantly worse than the Control group on the VLT and the Modified Six Elements Test (MSET) but the other four neuropsychological measures of EF failed to differentiate the groups. Both the MSET and the VLT significantly predicted everyday EF suggesting that they are both ecologically valid tools for the assessment of EF. The VLT has the advantage over the MSET of providing objective measurement of individual components of EF.

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

Multiplex social ecological network analysis reveals how social changes affect community robustness more than resource depletion.

PubMed

Baggio, Jacopo A; BurnSilver, Shauna B; Arenas, Alex; Magdanz, James S; Kofinas, Gary P; De Domenico, Manlio

2016-11-29

Network analysis provides a powerful tool to analyze complex influences of social and ecological structures on community and household dynamics. Most network studies of social-ecological systems use simple, undirected, unweighted networks. We analyze multiplex, directed, and weighted networks of subsistence food flows collected in three small indigenous communities in Arctic Alaska potentially facing substantial economic and ecological changes. Our analysis of plausible future scenarios suggests that changes to social relations and key households have greater effects on community robustness than changes to specific wild food resources.

Ecological Responses to Trout Habitat Rehabilitation in a Northern Michigan Stream

NASA Astrophysics Data System (ADS)

Rosi-Marshall, Emma J.; Moerke, Ashley H.; Lamberti, Gary A.

2006-07-01

Monitoring of stream restoration projects is often limited and success often focuses on a single taxon (e.g., salmonids), even though other aspects of stream structure and function may also respond to restoration activities. The Ottawa National Forest (ONF), Michigan, conducted a site-specific trout habitat improvement to enhance the trout fishery in Cook’s Run, a 3rd-order stream that the ONF determined was negatively affected by past logging. Our objectives were to determine if the habitat improvement increased trout abundances and enhanced other ecological variables (overall habitat quality, organic matter retention, seston concentration, periphyton abundance, sediment organic matter content, and macroinvertebrate abundance and diversity) following rehabilitation. The addition of skybooms (underbank cover structures) and k-dams (pool-creating structures) increased the relative abundance of harvestable trout (>25 cm in total length) as intended but not overall trout abundances. Both rehabilitation techniques also increased maximum channel depth and organic matter retention, but only k-dams increased overall habitat quality. Neither approach significantly affected other ecological variables. The modest ecological response to this habitat improvement likely occurred because the system was not severely degraded beforehand, and thus small, local changes in habitat did not measurably affect most physical and ecological variables measured. However, increases in habitat volume and in organic matter retention may enhance stream biota in the long term.

Ethnic variation in environmental belief and behavior: An examination of the new ecological paradigm in a social psychological context

Treesearch

Cassandra Y. Johnson; J. Michael Bowker; H. Ken Cordell

2004-01-01

We use national-level data to test a modified version of Stern, Dietz, & Guagnano's causal model of environmental belief and behavior. We focus on ethnic variation for four environmental behaviors: environmental reading, household recycling, environmental group joining, and participation in nature-based outdoor recreation. Blacks and foreign-born Latinos were...

75 FR 72807 - Taking of Marine Mammals Incidental to Specified Activities; U.S. Marine Corps Training Exercises...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-26

... biology and ecology within Pamlico Sound can be found in the proposed IHA Federal Register notice prepared... microPa\\2\\ = sec). Rupture. Injurious Physiological...... Onset Slight Goertner modified indexed to 13...-injurious Physiological.. TTS Greatest energy flux 182 dB re 1 Level B. density level in any microPa\\2...

Adaptation of the QBR index for use in riparian forests of central Ohio

Treesearch

Stephanie R. Colwell; David M. Hix

2008-01-01

Although high quality riparian forests are an endangered ecosystem type throughout the world, there has been no ecological index to measure the habitat quality of riparian forests in Ohio. The QBR (qualitat del bosc de ribera, or riparian forest quality) index was developed to assess the quality of habitat in Mediterranean forested riparian areas, and we have modified...

Simulating the dynamics of linear forests in great plains agroecosystems under changing climates

Treesearch

Qinfeng Guo; J. Brandle; Michele Schoeneberger; D. Buettner

2004-01-01

Most forest growth models are not suitable for the highly fragmented, linear (or linearly shaped) forests in the Great Plains agroecosystems (e.g., windbreaks, riparian forest buffers), where such forests are a minor but ecologically important component of the land mosaics. This study used SEEI)SCAPE, a recently modified gap model designed for cultivated land mosaics...

Climate differentiates forest structure across a residential macrosystem

EPA Science Inventory

The extent of urban ecological homogenization depends on how humans build, inhabit, and manage cities. Morphological and socio-economic facets of neighborhoods can drive the homogenization of forest cover, thus affecting urban ecological and hydrological processes, and ecosystem...

Ecological homogenization of residential macrosystems

Treesearch

Peter M. Groffman; Meghan Avolio; Jeannine Cavender-Bares; Neil D. Bettez; J. Morgan Grove; Sharon J. Hall; Sarah E. Hobbie; Kelli L. Larson; Susannah B. Lerman; Dexter H. Locke; James B. Heffernan; Jennifer L. Morse; Christopher Neill; Kristen C. Nelson; Jarlath O' Neil-Dunne; Diane E. Pataki; Colin Polsky; Rinku Roy Chowdhury; Tara L. E. Trammell

2017-01-01

Similarities in planning, development and culture within urban areas may lead to the convergence of ecological processes on continental scales. Transdisciplinary, multi-scale research is now needed to understand and predict the impact of human-dominated landscapes on ecosystem structure and function.

Nutritional physiology and ecology of wildlife in a changing world

PubMed Central

Peiman, Kathryn S.; Raubenheimer, David; Cooke, Steven J.

2017-01-01

Abstract Over the last century, humans have modified landscapes, generated pollution and provided opportunities for exotic species to invade areas where they did not evolve. In addition, humans now interact with animals in a growing number of ways (e.g. ecotourism). As a result, the quality (i.e. nutrient composition) and quantity (i.e. food abundance) of dietary items consumed by wildlife have, in many cases, changed. We present representative examples of the extent to which vertebrate foraging behaviour, food availability (quantity and quality) and digestive physiology have been modified due to human-induced environmental changes and human activities. We find that these effects can be quite extensive, especially as a result of pollution and human-provisioned food sources (despite good intentions). We also discuss the role of nutrition in conservation practices, from the perspective of both in situ and ex situ conservation. Though we find that the changes in the nutritional ecology and physiology of wildlife due to human alterations are typically negative and largely involve impacts on foraging behaviour and food availability, the extent to which these will affect the fitness of organisms and result in evolutionary changes is not clearly understood, and requires further investigation. PMID:28740638

'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.

A modified method for determining tannin-protein precipitation capacity using accelerated solvent extraction (ASE) and microplate gel filtration.

PubMed

McArt, Scott H; Spalinger, Donald E; Kennish, John M; Collins, William B

2006-06-01

The protein precipitation assay used by Robbins et al., (1987) Ecology 68:98-107 has been shown to predict successfully the reduction in protein availability to some ruminants due to tannins. The procedure, however, is expensive and laborious, which limits its utility, especially for quantitative ecological or nutritional applications where large numbers of assays may be required. We have modified the method to decrease its cost and increase laboratory efficiency by: (1) automating the extraction by using Accelerated Solvent Extraction (ASE); and (2) by scaling and automating the precipitation reaction, chromatography, and spectrometry with microplate gel filtration and an automated UV-VIS microplate spectrometer. ASE extraction is shown to be as effective at extracting tannins as the hot methanol technique. Additionally, the microplate assay is sensitive and precise. We show that the results from the new technique correspond in a nearly 1:1 relationship to the results of the previous technique. Hence, this method could reliably replace the older method with no loss in relevance to herbivore protein digestion. Moreover, the ASE extraction technique should be applicable to other tannin-protein precipitation assays and possibly other phenolic assays.

Nutritional physiology and ecology of wildlife in a changing world.

PubMed

Birnie-Gauvin, Kim; Peiman, Kathryn S; Raubenheimer, David; Cooke, Steven J

2017-01-01

Over the last century, humans have modified landscapes, generated pollution and provided opportunities for exotic species to invade areas where they did not evolve. In addition, humans now interact with animals in a growing number of ways (e.g. ecotourism). As a result, the quality (i.e. nutrient composition) and quantity (i.e. food abundance) of dietary items consumed by wildlife have, in many cases, changed. We present representative examples of the extent to which vertebrate foraging behaviour, food availability (quantity and quality) and digestive physiology have been modified due to human-induced environmental changes and human activities. We find that these effects can be quite extensive, especially as a result of pollution and human-provisioned food sources (despite good intentions). We also discuss the role of nutrition in conservation practices, from the perspective of both in situ and ex situ conservation. Though we find that the changes in the nutritional ecology and physiology of wildlife due to human alterations are typically negative and largely involve impacts on foraging behaviour and food availability, the extent to which these will affect the fitness of organisms and result in evolutionary changes is not clearly understood, and requires further investigation.

Geomorphometric correlations of vegetation cover properties and topographic karst features based on high-resolution LiDAR DTM of Aggtelek Karst, NE Hungary

NASA Astrophysics Data System (ADS)

Székely, Balázs; Telbisz, Tamás; Koma, Zsófia; Kelemen, Kristóf; Szmorad, Ferenc; Deák, Márton; Látos, Tamás; Standovár, Tibor

2015-04-01

Topography and lithology are two major factors influencing the vegetation cover, its mosaic pattern and lateral transitions. In karstic areas the topography has a high diversity, microtopographic landforms influence the local ecological setting, vegetation structure. Presence of sinkholes of various sizes and geometric arrangements causes rapid lateral variation of the slope, aspect patterns as well as highly modify the soil water balance in time and space. These diversity of factors defines a mosaicked habitat pattern for vegetation assemblages. The World Heritage Site Aggtelek Karst/Slovakian Karst Caves has characteristic natural and environmental properties concerning the geomorphological as well as the ecological values. In order to be able to study the topographic influence on the ecological setting, a high-resolution digital terrain model (DTM) and digital surface model (DSM) have been derived from airborne laser scanning data depicting the karstic micro- and macrotopographic Landscape elements and the envelope surface of the canopy. Additional vegetation parameters like closure and average height have been derived from a normalized digital surface model (nDSM). Extensive mapping of vegetation properties has been carried out: centered on points of a grid array several vegetation-specific data - including composition and structure of tree and shrub layers, herbacesous vegetation and tree regeneration - have been acquired. Various classification patterns - based on trees pecies composition, vertical vegetation structure - have been derived from this data set. The comparison of the vegetation classification data and the geomorphometric DTM derivatives yielded interesting results. Certain vegetation characteristics often correlate with the geomorphometric properties. We interpret this similarity as sensitivity of vegetion to fine-scale variations in geomorphic properties like aspect, illumination conditions and soil properties. However, in many cases the vegetation pattern shows no correlation with natural settings. It may be the result of human impact, which actively formed the local land use in these hilly-low mountain karst area since the Middle Ages. These studies have been financed partly by the following projects: data acquisition: "Hungarian-Slovakian Transnational Cooperation Programme 2007-2013", "Management of World Heritage Aggtelek Karst/Slovakian Karst Caves" (HUSK/1101/221/0180, Aggtelek NP), data evaluation: 'Multipurpose assessment serving forest biodiversity conservation in the Carpathian region of Hungary', Swiss-Hungarian Cooperation Programme (SH/4/13 Project), and Hungarian National Research Fund OTKA NK83400 and OTKA 104811. BS contributed as an Alexander von Humboldt Research Fellow, TT was supported by the János Bolyai Scolarship of the Hungarian Academy of Sciences.

Quantifying patterns of change in marine ecosystem response to multiple pressures.

PubMed

Large, Scott I; Fay, Gavin; Friedland, Kevin D; Link, Jason S

2015-01-01

The ability to understand and ultimately predict ecosystem response to multiple pressures is paramount to successfully implement ecosystem-based management. Thresholds shifts and nonlinear patterns in ecosystem responses can be used to determine reference points that identify levels of a pressure that may drastically alter ecosystem status, which can inform management action. However, quantifying ecosystem reference points has proven elusive due in large part to the multi-dimensional nature of both ecosystem pressures and ecosystem responses. We used ecological indicators, synthetic measures of ecosystem status and functioning, to enumerate important ecosystem attributes and to reduce the complexity of the Northeast Shelf Large Marine Ecosystem (NES LME). Random forests were used to quantify the importance of four environmental and four anthropogenic pressure variables to the value of ecological indicators, and to quantify shifts in aggregate ecological indicator response along pressure gradients. Anthropogenic pressure variables were critical defining features and were able to predict an average of 8-13% (up to 25-66% for individual ecological indicators) of the variation in ecological indicator values, whereas environmental pressures were able to predict an average of 1-5 % (up to 9-26% for individual ecological indicators) of ecological indicator variation. Each pressure variable predicted a different suite of ecological indicator's variation and the shapes of ecological indicator responses along pressure gradients were generally nonlinear. Threshold shifts in ecosystem response to exploitation, the most important pressure variable, occurred when commercial landings were 20 and 60% of total surveyed biomass. Although present, threshold shifts in ecosystem response to environmental pressures were much less important, which suggests that anthropogenic pressures have significantly altered the ecosystem structure and functioning of the NES LME. Gradient response curves provide ecologically informed transformations of pressure variables to explain patterns of ecosystem structure and functioning. By concurrently identifying thresholds for a suite of ecological indicator responses to multiple pressures, we demonstrate that ecosystem reference points can be evaluated and used to support ecosystem-based management.

Classification of wetlands and deepwater habitats of the United States

USGS Publications Warehouse

Cowardin, L.M.; Carter, V.; Golet, F.C.; LaRoe, E.T.

1985-01-01

This classification, to be used in a new inventory of wetlands and deepwater habitats of the United States, is intended to describe ecological taxa, arrange them in a system useful to resource managers, furnish units for mapping, and provide uniformity of concepts and terms. Wetlands are defined by plants (hydrophytes), soils (hydric soils), and frequency of flooding. Ecologically related areas of deep water, traditionally not considered wetlands, are included in the classification as deepwater habitats.Systems form the highest level of the classification hierarchy; five are defined-Marine, Estuarine, Riverine, Lacustrine, and Palustrine. Marine and Estuarine Systems each have two Subsystems, Subtidal and Intertidal; the Riverine System has four Subsystems, Tidal, Lower Perennial, Upper Perennial, and Intermittent; the Lacustrine has two, Littoral and Limnetic; and the Palustrine has no Subsystems.Within the Subsystems, Classes are based on substrate material and flooding regime, or on vegetative life form. The same Classes may appear under one or more of the Systems or Subsystems. Six Classes are based on substrate and flooding regime: (1) Rock Bottom with a substrate of bedrock, boulders, or stones; (2) Unconsolidated Bottom with a substrate of cobbles, gravel, sand, mud, or organic material; (3) Rocky Shore with the same substrates as Rock Bottom; (4) Unconsolidated Shore with the same substrates as Unconsolidated Bottom; (5) Streambed with any of the substrates; and (6) Reef with a substrate composed of the living and dead remains of invertebrates (corals, mollusks, or worms). The bottom Classes, (1) and (2) above, are flooded all or most of the time and the shore Classes, (3) and (4), are exposed most of the time. The Class Streambed is restricted to channels of intermittent streams and tidal channels that are dewatered at low tide. The life form of the dominant vegetation defines the five Classes based on vegetative form: (1) Aquatic Bed, dominated by plants that grow principally on or below the surface of the water; (2) Moss-Lichen Wetland, dominated by mosses or lichens; (3) Emergent Wetland, dominated by emergent herbaceous angiosperms; (4) Scrub-Shrub Wetland, dominated by shrubs or small trees; and (5) Forested Wetland, dominated by large trees.The Dominance Type, which is named for the dominant plant or animal forms, is the lowest level of the classification hierarchy. Only examples are provided for this level; Dominance Types must be developed by individual users of the classification.Modifying terms applied to the Classes or Subclasses are essential for use of the system. In tidal areas, the type and duration of flooding are described by four Water Regime Modifiers: subtidal, irregularly exposed, regularly flooded, and irregularly flooded. In nontidal areas, eight Regimes are used: permanently flooded, intermittently exposed, semipermanently flooded, seasonally flooded, saturated, temporarily flooded, intermittently flooded, and artificially flooded. A hierarchical system of Water Chemistry Modifiers, adapted from the Venice System, is used to describe the salinity of the water. Fresh waters are further divided on the basis of pH. Use of a hierarchical system of soil modifiers taken directly from U.S. soil taxonomy is also required. Special modifiers are used where appropriate: excavated, impounded, diked, partly drained, farmed, and artificial.Regional differences important to wetland ecology are described through a regionalization that combines a system developed for inland areas by R. G. Bailey in 1976 with our Marine and Estuarine provinces.The structure of the classification allows it to be used at any of several hierarchical levels. Special data required for detailed application of the system are frequently unavailable, and thus data gathering may be prerequisite to classification. Development of rules by the user will be required for specific map scales. Dominance Types and relationships of plant and anima

Classification of wetlands and deepwater habitats of the United States

USGS Publications Warehouse

Cowardin, L.M.; Carter, V.; Golet, F.C.; LaRoe, E.T.

1979-01-01

This classification, to be used in a new inventory of wetlands and deepwater habitats of the United States, is intended to describe ecological taxa, arrange them in a system useful to resource managers, furnish units for mapping, and provide uniformity of concepts and terms. Wetlands are defined by plants (hydrophytes), soils (hydric soils), and frequency of flooding. Ecologically related areas of deep water, traditionally not considered wetlands, are included in the classification as deepwater habitats.Systems form the highest level of the classification hierarchy; five are defined--Marine, Estuarine, Riverine, Lacustrine, and Palustrine. Marine and Estuarine systems each have two subsystems, Subtidal and Intertidal; the Riverine system has four subsystems, Tidal, Lower Perennial, Upper Perennial, and Intermittent; the Lacustrine has two, Littoral and Limnetic; and the Palustrine has no subsystem.Within the subsystems, classes are based on substrate material and flooding regime, or on vegetative life form. The same classes may appear under one or more of the systems or subsystems. Six classes are based on substrate and flooding regime: (1) Rock Bottom with a substrate of bedrock, boulders, or stones; (2) Unconsolidated Bottom with a substrate of cobbles, gravel, sand, mud, or organic material; (3) Rocky Shore with the same substrate as Rock Bottom; (4) Unconsolidated Shore with the same substrate as Unconsolidated Bottom; (5) Streambed with any of the substrates; and (6) Reef with a substrate composed of the living and dead remains of invertebrates (corals, mollusks, or worms). The bottom classes, (1) and (2) above, are flooded all or most of the time and the shore classes, (3) and (4), are exposed most of the time. The class Streambed is restricted to channels of intermittent streams and tidal channels that are dewatered at low tide. The life form of the dominant vegetation defines the five classes based on vegetative form: (1) Aquatic Bed, dominated by plants that grow principally on or below the surface of the water; (2) Moss-Lichen Wetland, dominated by mosses or lichens; (3) Emergent Wetland, dominated by emergent herbaceous angiosperms; (4) Scrub-Shrub Wetland, dominated by shrubs or small trees; and (5) Forested Wetland, dominated by large trees.The dominance type, which is named for the dominant plant or animal forms, is the lowest level of the classification hierarchy. Only examples are provided for this level; dominance types must be developed by individual users of the classification.Modifying terms applied to the classes or subclasses are essential for use of the system. In tidal areas, the type and duration of flooding are described by four water regime modifiers: subtidal, irregularly exposed, regularly flooded, and irregularly flooded. In nontidal areas, six regimes are used: permanently flooded, intermittently exposed, semipermanently flooded, seasonally flooded, saturated, temporarily flooded, intermittently flooded, and artificially flooded. A hierarchical system of water chemistry modifiers, adapted from the Venice System, is used to describe the salinity of the water. Fresh waters are further divided on the basis of pH. Use of a hierarchical system of soil modifiers taken directly from U.S. soil taxonomy is also required. Special modifiers are used where appropriate: excavated, impounded, diked, partly drained, farmed, and artificial.Regional differences important to wetland ecology are described through a regionalization that combines a system developed for inland areas by R. G. Bailey in 1976 with our Marine and Estuarine provinces.The structure of the classification allows it to be used at any of several hierarchical levels. Special data required for detailed application of the system are frequently unavailable, and thus data gathering may be prerequisite to classification. Development of rules by the user will be required for specific map scales. Dominance types and relationships of plant and animal co

Forest restoration: a global dataset for biodiversity and vegetation structure.

PubMed

Crouzeilles, Renato; Ferreira, Mariana S; Curran, Michael

2016-08-01

Restoration initiatives are becoming increasingly applied around the world. Billions of dollars have been spent on ecological restoration research and initiatives, but restoration outcomes differ widely among these initiatives in part due to variable socioeconomic and ecological contexts. Here, we present the most comprehensive dataset gathered to date on forest restoration. It encompasses 269 primary studies across 221 study landscapes in 53 countries and contains 4,645 quantitative comparisons between reference ecosystems (e.g., old-growth forest) and degraded or restored ecosystems for five taxonomic groups (mammals, birds, invertebrates, herpetofauna, and plants) and five measures of vegetation structure reflecting different ecological processes (cover, density, height, biomass, and litter). We selected studies that (1) were conducted in forest ecosystems; (2) had multiple replicate sampling sites to measure indicators of biodiversity and/or vegetation structure in reference and restored and/or degraded ecosystems; and (3) used less-disturbed forests as a reference to the ecosystem under study. We recorded (1) latitude and longitude; (2) study year; (3) country; (4) biogeographic realm; (5) past disturbance type; (6) current disturbance type; (7) forest conversion class; (8) restoration activity; (9) time that a system has been disturbed; (10) time elapsed since restoration started; (11) ecological metric used to assess biodiversity; and (12) quantitative value of the ecological metric of biodiversity and/or vegetation structure for reference and restored and/or degraded ecosystems. These were the most common data available in the selected studies. We also estimated forest cover and configuration in each study landscape using a recently developed 1 km consensus land cover dataset. We measured forest configuration as the (1) mean size of all forest patches; (2) size of the largest forest patch; and (3) edge:area ratio of forest patches. Global analyses of the factors influencing ecological restoration success at both the local and landscape scale are urgently needed to guide restoration initiatives and to further develop restoration knowledge in a topic area of much contemporary interest. © 2016 by the Ecological Society of America.

The role of Dynamic Energy Budget theory in predictive modeling of stressor impacts on ecological systems. Comment on: ;Physics of metabolic organization; by Marko Jusup et al.

NASA Astrophysics Data System (ADS)

Galic, Nika; Forbes, Valery E.

2017-03-01

Human activities have been modifying ecosystems for centuries, from pressures on wild populations we harvest to modifying habitats through urbanization and agricultural activities. Changes in global climate patterns are adding another layer of, often unpredictable, perturbations to ecosystems on which we rely for life support [1,2]. To ensure the sustainability of ecosystem services, especially at this point in time when the human population is estimated to grow by another 2 billion by 2050 [3], we need to predict possible consequences of our actions and suggest relevant solutions [4,5]. We face several challenges when estimating adverse impacts of our actions on ecosystems. We describe these in the context of ecological risk assessment of chemicals. Firstly, when attempting to assess risk from exposure to chemicals, we base our decisions on a very limited number of species that are easily cultured and kept in the lab. We assume that preventing risk to these species will also protect all of the untested species present in natural ecosystems [6]. Secondly, although we know that chemicals interact with other stressors in the field, the number of stressors that we can test is limited due to logistical and ethical reasons. Similarly, empirical approaches are limited in both spatial and temporal scale due to logistical, financial and ethical reasons [7,8]. To bypass these challenges, we can develop ecological models that integrate relevant life history and other information and make testable predictions across relevant spatial and temporal scales [8-10].

Rapid evolution of introduced tree pathogens via episodic selection and horizontal gene transfer

Treesearch

Clive Brasier

2012-01-01

Routine selection is simply defined as “the ecological constraints experienced by an endemic organism that favor a relatively stable but fluctuating population structure over time.” Its antithesis is episodic selection, defined as “any sudden ecological disturbance likely to lead to a significant alteration in a species’ population structure” (Brasier 1986, 1995). In...

Decay of interspecific avian flock networks along a disturbance gradient in Amazonia.

PubMed

Mokross, Karl; Ryder, Thomas B; Côrtes, Marina Corrêa; Wolfe, Jared D; Stouffer, Philip C

2014-02-07

Our understanding of how anthropogenic habitat change shapes species interactions is in its infancy. This is in large part because analytical approaches such as network theory have only recently been applied to characterize complex community dynamics. Network models are a powerful tool for quantifying how ecological interactions are affected by habitat modification because they provide metrics that quantify community structure and function. Here, we examine how large-scale habitat alteration has affected ecological interactions among mixed-species flocking birds in Amazonian rainforest. These flocks provide a model system for investigating how habitat heterogeneity influences non-trophic interactions and the subsequent social structure of forest-dependent mixed-species bird flocks. We analyse 21 flock interaction networks throughout a mosaic of primary forest, fragments of varying sizes and secondary forest (SF) at the Biological Dynamics of Forest Fragments Project in central Amazonian Brazil. Habitat type had a strong effect on network structure at the levels of both species and flock. Frequency of associations among species, as summarized by weighted degree, declined with increasing levels of forest fragmentation and SF. At the flock level, clustering coefficients and overall attendance positively correlated with mean vegetation height, indicating a strong effect of habitat structure on flock cohesion and stability. Prior research has shown that trophic interactions are often resilient to large-scale changes in habitat structure because species are ecologically redundant. By contrast, our results suggest that behavioural interactions and the structure of non-trophic networks are highly sensitive to environmental change. Thus, a more nuanced, system-by-system approach may be needed when thinking about the resiliency of ecological networks.

Investigation of ecological parameters of four-stroke SI engine, with pneumatic fuel injection system

NASA Astrophysics Data System (ADS)

Marek, W.; Śliwiński, K.

2016-09-01

The publication presents the results of tests to determine the impact of using waste fuels, alcohol, to power the engine, on the ecological parameters of the combustion engine. Alternatively fuelled with a mixture of iso- and n-butanol, indicated with "X" and "END, and gasoline and a mixture of fuel and alcohol. The object of the study was a four-stroke engine with spark ignition designed to work with a generator. Motor power was held by the modified system of pneumatic injection using hot exhaust gases developed by Prof. Stanislaw Jarnuszkiewicz, controlled by modern mechatronic systems. Tests were conducted at a constant speed for the intended use of the engine. The subject of the research was to determine the control parameters such as ignition timing, mixture composition and the degree of exhaust gas recirculation on the ecological parameters of the engine. Tests were carried out using partially quality power control. In summary we present the findings of this phase of the study.

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.

Climate change has indirect effects on resource use and overlap among coexisting bird species with negative consequences for their reproductive success

USGS Publications Warehouse

Martin, Thomas E.; Auer, Sonya K.

2013-01-01

Climate change can modify ecological interactions, but whether it can have cascading effects throughout ecological networks of multiple interacting species remains poorly studied. Climate-driven alterations in the intensity of plant–herbivore interactions may have particularly profound effects on the larger community because plants provide habitat for a wide diversity of organisms. Here we show that changes in vegetation over the last 21 years, due to climate effects on plant–herbivore interactions, have consequences for songbird nest site overlap and breeding success. Browsing-induced reductions in the availability of preferred nesting sites for two of three ground nesting songbirds led to increasing overlap in nest site characteristics among all three bird species with increasingly negative consequences for reproductive success over the long term. These results demonstrate that changes in the vegetation community from effects of climate change on plant–herbivore interactions can cause subtle shifts in ecological interactions that have critical demographic ramifications for other species in the larger community.

Global Salmonidae introductions reveal stronger ecological effects of changing intraspecific compared to interspecific diversity.

PubMed

Buoro, Mathieu; Olden, Julian D; Cucherousset, Julien

2016-11-01

The introduction of organisms within the native range of wild conspecifics is a widespread phenomenon and locally modifies patterns in intraspecific diversity. However, our knowledge of the resulting ecological effects, as opposed to those caused by invasion-induced changes in interspecific diversity, is still limited. Here, we investigated the ecological effects of native and non-native invaders across levels of biological organisations and recipient organisms using the global and long history introductions of salmonids. Our meta-analysis demonstrated that the global effects of native species introductions exceeded those induced by non-native invaders. The impacts of native invaders were primarily manifested at the individual level on wild conspecifics, but remained largely unexplored on other native organisms and at the community and ecosystem levels. Overlooked and poorly appreciated, quantifying the impacts of native invaders has important implications because human-assisted introductions of domesticated organisms are ubiquitous and likely to proliferate in the future. © 2016 John Wiley & Sons Ltd/CNRS.

Transforming Social Regularities in a Multicomponent Community-Based Intervention: A Case Study of Professionals' Adaptability to Better Support Parents to Meet Their Children's Needs.

PubMed

Quiroz Saavedra, Rodrigo; Brunson, Liesette; Bigras, Nathalie

2017-06-01

This paper presents an in-depth case study of the dynamic processes of mutual adjustment that occurred between two professional teams participating in a multicomponent community-based intervention (CBI). Drawing on the concept of social regularities, we focus on patterns of social interaction within and across the two microsystems involved in delivering the intervention. Two research strategies, narrative analysis and structural network analysis, were used to reveal the social regularities linking the two microsystems. Results document strategies and actions undertaken by the professionals responsible for the intervention to modify intersetting social regularities to deal with a problem situation that arose during the course of one intervention cycle. The results illustrate how key social regularities were modified in order to resolve the problem situation and allow the intervention to continue to function smoothly. We propose that these changes represent a transition to a new state of the ecological intervention system. This transformation appeared to be the result of certain key intervening mechanisms: changing key role relationships, boundary spanning, and synergy. The transformation also appeared to be linked to positive setting-level and individual-level outcomes: confidence of key team members, joint planning, decision-making and intervention activities, and the achievement of desired intervention objectives. © Society for Community Research and Action 2017.

Arctic systems in the Quaternary: ecological collision, faunal mosaics and the consequences of a wobbling climate.

PubMed

Hoberg, E P; Cook, J A; Agosta, S J; Boeger, W; Galbreath, K E; Laaksonen, S; Kutz, S J; Brooks, D R

2017-07-01

Climate oscillations and episodic processes interact with evolution, ecology and biogeography to determine the structure and complex mosaic that is the biosphere. Parasites and parasite-host assemblages are key components in a general explanatory paradigm for global biodiversity. We explore faunal assembly in the context of Quaternary time frames of the past 2.6 million years, a period dominated by episodic shifts in climate. Climate drivers cross a continuum from geological to contemporary timescales and serve to determine the structure and distribution of complex biotas. Cycles within cycles are apparent, with drivers that are layered, multifactorial and complex. These cycles influence the dynamics and duration of shifts in environmental structure on varying temporal and spatial scales. An understanding of the dynamics of high-latitude systems, the history of the Beringian nexus (the intermittent land connection linking Eurasia and North America) and downstream patterns of diversity depend on teasing apart the complexity of biotic assembly and persistence. Although climate oscillations have dominated the Quaternary, contemporary dynamics are driven by tipping points and shifting balances emerging from anthropogenic forces that are disrupting ecological structure. Climate change driven by anthropogenic forcing has supplanted a history of episodic variation and is eliminating ecological barriers and constraints on development and distribution for pathogen transmission. A framework to explore interactions of episodic processes on faunal structure and assembly is the Stockholm Paradigm, which appropriately shifts the focus from cospeciation to complexity and contingency in explanations of diversity.

Ecological research and management of intermittent rivers: an ...

EPA Pesticide Factsheets

Rivers and streams that do not flow permanently (herein intermittent rivers; IRs) make up a large proportion of the world's inland waters and are gaining widespread attention. We review the research on IRs from its early focus on natural history through to current application in management and policy.The few early studies of the ecology of IRs were largely descriptive. Nevertheless, in the 1970s, synthesis of this sparse research complemented work on temporary standing waters to found a powerful framework for much of the subsequent research on IRs.Research on the ecology and biogeochemistry of IRs continues to fuel our understanding of resistance and resilience to drying and flooding as disturbances. Syntheses of the growing literature, including cross-continental and cross-climate comparisons, are revealing the generality and individuality of ecological and ecosystem responses to flow cessation and surface water loss. Meanwhile, increasing numbers of experiments test the causality of these responses.Much of the increased consideration of IRs in research, management and policy is driven by the observed and projected shifts in flow regimes from perennial to intermittent associated with changes in land and water use and climate, superimposed on the high incidence of natural intermittency. The need to protect and better manage IRs is prompting researchers to develop new or modified methods to monitor flow status and assess the ecological condition of these systems.

Integrating structure-from-motion photogrammetry with geospatial software as a novel technique for quantifying 3D ecological characteristics of coral reefs

PubMed Central

Delparte, D; Gates, RD; Takabayashi, M

2015-01-01

The structural complexity of coral reefs plays a major role in the biodiversity, productivity, and overall functionality of reef ecosystems. Conventional metrics with 2-dimensional properties are inadequate for characterization of reef structural complexity. A 3-dimensional (3D) approach can better quantify topography, rugosity and other structural characteristics that play an important role in the ecology of coral reef communities. Structure-from-Motion (SfM) is an emerging low-cost photogrammetric method for high-resolution 3D topographic reconstruction. This study utilized SfM 3D reconstruction software tools to create textured mesh models of a reef at French Frigate Shoals, an atoll in the Northwestern Hawaiian Islands. The reconstructed orthophoto and digital elevation model were then integrated with geospatial software in order to quantify metrics pertaining to 3D complexity. The resulting data provided high-resolution physical properties of coral colonies that were then combined with live cover to accurately characterize the reef as a living structure. The 3D reconstruction of reef structure and complexity can be integrated with other physiological and ecological parameters in future research to develop reliable ecosystem models and improve capacity to monitor changes in the health and function of coral reef ecosystems. PMID:26207190

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.

Scrambled eggs: mechanical forces as ecological factors in early development.

PubMed

Moore, Steven W

2003-01-01

Many ecological interactions involve, at some level, mechanical forces and the movements or structural deformations they produce. Although the most familiar examples involve the functional morphology of adult structures, all life history stages (not just the adults) are subject to the laws of physics. Moreover, the success of every lineage depends on the success of every life history stage (again, not just the adults). Therefore, insights gained by using mechanical engineering principles and techniques to study ecological interactions between gametes, embryos, larvae, and their environment are essential to a well-rounded understanding of development, ecology, and evolution. Here I draw on examples from the literature and my own research to illustrate ways in which mechanical forces in the environment shape development. These include mechanical forces acting as selective factors (e.g., when coral gamete size and shape interact with turbulent water flow to determine fertilization success) and as developmental cues (e.g., when plant growth responds to gravity or bone growth responds to mechanical loading). I also examine the opposite cause-and-effect relationship by considering examples in which the development of organisms impacts ecologically relevant mechanical forces. Finally, I discuss the potential for ecological pattern formation as a result of feedback loops created by such bidirectional interactions between developmental processes and mechanical forces in the environment.

Widespread correlations between climatic niche evolution and species diversification in birds.

PubMed

Cooney, Christopher R; Seddon, Nathalie; Tobias, Joseph A

2016-07-01

The adaptability of species' climatic niches can influence the dynamics of colonization and gene flow across climatic gradients, potentially increasing the likelihood of speciation or reducing extinction in the face of environmental change. However, previous comparative studies have tested these ideas using geographically, taxonomically and ecologically restricted samples, yielding mixed results, and thus the processes linking climatic niche evolution with diversification remain poorly understood. Focusing on birds, the largest and most widespread class of terrestrial vertebrates, we test whether variation in species diversification among clades is correlated with rates of climatic niche evolution and the extent to which these patterns are modified by underlying gradients in biogeography and species' ecology. We quantified climatic niches, latitudinal distribution and ecological traits for 7657 (˜75%) bird species based on geographical range polygons and then used Bayesian phylogenetic analyses to test whether niche evolution was related to species richness and rates of diversification across genus- and family-level clades. We found that the rate of climatic niche evolution has a positive linear relationship with both species richness and diversification rate at two different taxonomic levels (genus and family). Furthermore, this positive association between labile climatic niches and diversification was detected regardless of variation in clade latitude or key ecological traits. Our findings suggest either that rapid adaptation to unoccupied areas of climatic niche space promotes avian diversification, or that diversification promotes adaptation. Either way, we propose that climatic niche evolution is a fundamental process regulating the link between climate and biodiversity at global scales, irrespective of the geographical and ecological context of speciation and extinction. © 2016 The Authors. Journal of Animal Ecology © 2016 British Ecological Society.

EPA ’s ECOLOGICAL MODELS FOR INTEGRATED WATERSHED MANAGEMENT

EPA Science Inventory

Aquatic ecological populations and communities are affected by the nature and quality of the water in which they live. Specific factors that affect instream biota include chemical variables, biotic interactions, energy source, flow regime, and habitat structure. As watershed mana...

40 CFR 82.172 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., clinical, and ecological, or other studies of a substitute and its components, and any other pertinent test... include: (1) Long- and short-term tests of mutagenicity, carcinogenicity, or teratogenicity; data on...; and structure/activity analyses; (2) Tests for ecological or other environmental effects on...

40 CFR 82.172 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., clinical, and ecological, or other studies of a substitute and its components, and any other pertinent test... include: (1) Long- and short-term tests of mutagenicity, carcinogenicity, or teratogenicity; data on...; and structure/activity analyses; (2) Tests for ecological or other environmental effects on...

40 CFR 82.172 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., clinical, and ecological, or other studies of a substitute and its components, and any other pertinent test... include: (1) Long- and short-term tests of mutagenicity, carcinogenicity, or teratogenicity; data on...; and structure/activity analyses; (2) Tests for ecological or other environmental effects on...

40 CFR 82.172 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., clinical, and ecological, or other studies of a substitute and its components, and any other pertinent test... include: (1) Long- and short-term tests of mutagenicity, carcinogenicity, or teratogenicity; data on...; and structure/activity analyses; (2) Tests for ecological or other environmental effects on...

40 CFR 82.172 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., clinical, and ecological, or other studies of a substitute and its components, and any other pertinent test... include: (1) Long- and short-term tests of mutagenicity, carcinogenicity, or teratogenicity; data on...; and structure/activity analyses; (2) Tests for ecological or other environmental effects on...

DISTURBANCE PATTERNS IN A SOCIO-ECOLOGICAL SYSTEM AT MULTIPLE SCALES

EPA Science Inventory

Ecological systems with hierarchical organization and non-equilibrium dynamics require multiple-scale analyses to comprehend how a system is structured and to formulate hypotheses about regulatory mechanisms. Characteristic scales in real landscapes are determined by, or at least...

Functions of parental involvement and effects of school climate on bullying behaviors among South Korean middle school students.

PubMed

Lee, Chang-Hun; Song, Juyoung

2012-08-01

This study uses an ecological systems theory to understand bullying behavior. Emphasis is given to overcome limitations found in the literature, such as very little empirical research on functions of parental involvement and the impacts of school climate on bullying as an outcome variable. Two functions of parental involvement investigated are (a) bridging the negative experiences within the family with bullying behaviors at schools, and (b) influencing school climate. Bullying behaviors were measured by a modified Korean version of Olweus' bully/victim questionnaire (reliability range: .78-.84) from 1,238 randomly selected Korean middle school students in 2007. Findings from structural equation modeling (SEM) analyses showed that (a) individual traits are one of the most important influence on bullying, (b) negative experiences in the family do not have direct influence on bullying behaviors at school, (c) parental involvement influences school climate, and (d) positive school climate was negatively related to bullying behaviors.

Challenging the paradigms of deep-sea ecology.

PubMed

Danovaro, Roberto; Snelgrove, Paul V R; Tyler, Paul

2014-08-01

Deep-sea ecosystems represent Earth's major ecological research frontier. Focusing on seafloor ecosystems, we demonstrate how new technologies underpin discoveries that challenge major ecological hypotheses and paradigms, illuminating new deep-sea geosphere-biosphere interactions. We now recognize greater habitat complexity, new ecological interactions and the importance of 'dark energy', and chemosynthetic production in fuelling biodiversity. We also acknowledge functional hotspots that contradict a food-poor, metabolically inactive, and minor component of global carbon cycles. Symbioses appear widespread, revealing novel adaptations. Populations show complex spatial structure and evolutionary histories. These new findings redefine deep-sea ecology and the role of Earth's largest biome in global biosphere functioning. Indeed, deep-sea exploration can open new perspectives in ecological research to help mitigate exploitation impacts. Copyright © 2014 Elsevier Ltd. All rights reserved.

Evolution of egg coats: linking molecular biology and ecology.

PubMed

Shu, Longfei; Suter, Marc J-F; Räsänen, Katja

2015-08-01

One central goal of evolutionary biology is to explain how biological diversity emerges and is maintained in nature. Given the complexity of the phenotype and the multifaceted nature of inheritance, modern evolutionary ecological studies rely heavily on the use of molecular tools. Here, we show how molecular tools help to gain insight into the role of egg coats (i.e. the extracellular structures surrounding eggs and embryos) in evolutionary diversification. Egg coats are maternally derived structures that have many biological functions from mediating fertilization to protecting the embryo from environmental hazards. They show great molecular, structural and functional diversity across species, but intraspecific variability and the role of ecology in egg coat evolution have largely been overlooked. Given that much of the variation that influences egg coat function is ultimately determined by their molecular phenotype, cutting-edge molecular tools (e.g. proteomics, glycomics and transcriptomics), combined with functional assays, are needed for rigorous inferences on their evolutionary ecology. Here, we identify key research areas and highlight emerging molecular techniques that can increase our understanding of the role of egg coats in the evolution of biological diversity, from adaptation to speciation. © 2015 John Wiley & Sons Ltd.

Ecological consequences of colony structure in dynamic ant nest networks.

PubMed

Ellis, Samuel; Franks, Daniel W; Robinson, Elva J H

2017-02-01

Access to resources depends on an individual's position within the environment. This is particularly important to animals that invest heavily in nest construction, such as social insects. Many ant species have a polydomous nesting strategy: a single colony inhabits several spatially separated nests, often exchanging resources between the nests. Different nests in a polydomous colony potentially have differential access to resources, but the ecological consequences of this are unclear. In this study, we investigate how nest survival and budding in polydomous wood ant ( Formica lugubris ) colonies are affected by being part of a multi-nest system. Using field data and novel analytical approaches combining survival models with dynamic network analysis, we show that the survival and budding of nests within a polydomous colony are affected by their position in the nest network structure. Specifically, we find that the flow of resources through a nest, which is based on its position within the wider nest network, determines a nest's likelihood of surviving and of founding new nests. Our results highlight how apparently disparate entities in a biological system can be integrated into a functional ecological unit. We also demonstrate how position within a dynamic network structure can have important ecological consequences.

Fine-scale population dynamics in a marine fish species inferred from dynamic state-space models.

PubMed

Rogers, Lauren A; Storvik, Geir O; Knutsen, Halvor; Olsen, Esben M; Stenseth, Nils C

2017-07-01

Identifying the spatial scale of population structuring is critical for the conservation of natural populations and for drawing accurate ecological inferences. However, population studies often use spatially aggregated data to draw inferences about population trends and drivers, potentially masking ecologically relevant population sub-structure and dynamics. The goals of this study were to investigate how population dynamics models with and without spatial structure affect inferences on population trends and the identification of intrinsic drivers of population dynamics (e.g. density dependence). Specifically, we developed dynamic, age-structured, state-space models to test different hypotheses regarding the spatial structure of a population complex of coastal Atlantic cod (Gadus morhua). Data were from a 93-year survey of juvenile (age 0 and 1) cod sampled along >200 km of the Norwegian Skagerrak coast. We compared two models: one which assumes all sampled cod belong to one larger population, and a second which assumes that each fjord contains a unique population with locally determined dynamics. Using the best supported model, we then reconstructed the historical spatial and temporal dynamics of Skagerrak coastal cod. Cross-validation showed that the spatially structured model with local dynamics had better predictive ability. Furthermore, posterior predictive checks showed that a model which assumes one homogeneous population failed to capture the spatial correlation pattern present in the survey data. The spatially structured model indicated that population trends differed markedly among fjords, as did estimates of population parameters including density-dependent survival. Recent biomass was estimated to be at a near-record low all along the coast, but the finer scale model indicated that the decline occurred at different times in different regions. Warm temperatures were associated with poor recruitment, but local changes in habitat and fishing pressure may have played a role in driving local dynamics. More generally, we demonstrated how state-space models can be used to test evidence for population spatial structure based on survey time-series data. Our study shows the importance of considering spatially structured dynamics, as the inferences from such an approach can lead to a different ecological understanding of the drivers of population declines, and fundamentally different management actions to restore populations. © 2017 The Authors. Journal of Animal Ecology published by John Wiley & Sons Ltd on behalf of British Ecological Society.

Pavement-Transportation Computer Assisted Structural Engineering (PCASE) Implementation of the Modified Berggren (ModBerg) Equation for Computing the Frost Penetration Depth within Pavement Structures

DTIC Science & Technology

2012-04-01

ER D C/ G SL T R -1 2 -1 5 Pavement -Transportation Computer Assisted Structural Engineering (PCASE) Implementation of the Modified...Berggren (ModBerg) Equation for Computing the Frost Penetration Depth within Pavement Structures G eo te ch n ic al a n d S tr u ct u re s La b or at...April 2012 Pavement -Transportation Computer Assisted Structural Engineering (PCASE) Implementation of the Modified Berggren (ModBerg) Equation for

Evolutionary impact assessment: accounting for evolutionary consequences of fishing in an ecosystem approach to fisheries management.

PubMed

Laugen, Ane T; Engelhard, Georg H; Whitlock, Rebecca; Arlinghaus, Robert; Dankel, Dorothy J; Dunlop, Erin S; Eikeset, Anne M; Enberg, Katja; Jørgensen, Christian; Matsumura, Shuichi; Nusslé, Sébastien; Urbach, Davnah; Baulier, Loїc; Boukal, David S; Ernande, Bruno; Johnston, Fiona D; Mollet, Fabian; Pardoe, Heidi; Therkildsen, Nina O; Uusi-Heikkilä, Silva; Vainikka, Anssi; Heino, Mikko; Rijnsdorp, Adriaan D; Dieckmann, Ulf

2014-03-01

Managing fisheries resources to maintain healthy ecosystems is one of the main goals of the ecosystem approach to fisheries (EAF). While a number of international treaties call for the implementation of EAF, there are still gaps in the underlying methodology. One aspect that has received substantial scientific attention recently is fisheries-induced evolution (FIE). Increasing evidence indicates that intensive fishing has the potential to exert strong directional selection on life-history traits, behaviour, physiology, and morphology of exploited fish. Of particular concern is that reversing evolutionary responses to fishing can be much more difficult than reversing demographic or phenotypically plastic responses. Furthermore, like climate change, multiple agents cause FIE, with effects accumulating over time. Consequently, FIE may alter the utility derived from fish stocks, which in turn can modify the monetary value living aquatic resources provide to society. Quantifying and predicting the evolutionary effects of fishing is therefore important for both ecological and economic reasons. An important reason this is not happening is the lack of an appropriate assessment framework. We therefore describe the evolutionary impact assessment (EvoIA) as a structured approach for assessing the evolutionary consequences of fishing and evaluating the predicted evolutionary outcomes of alternative management options. EvoIA can contribute to EAF by clarifying how evolution may alter stock properties and ecological relations, support the precautionary approach to fisheries management by addressing a previously overlooked source of uncertainty and risk, and thus contribute to sustainable fisheries.

Evolutionary impact assessment: accounting for evolutionary consequences of fishing in an ecosystem approach to fisheries management

PubMed Central

Laugen, Ane T; Engelhard, Georg H; Whitlock, Rebecca; Arlinghaus, Robert; Dankel, Dorothy J; Dunlop, Erin S; Eikeset, Anne M; Enberg, Katja; Jørgensen, Christian; Matsumura, Shuichi; Nusslé, Sébastien; Urbach, Davnah; Baulier, Loїc; Boukal, David S; Ernande, Bruno; Johnston, Fiona D; Mollet, Fabian; Pardoe, Heidi; Therkildsen, Nina O; Uusi-Heikkilä, Silva; Vainikka, Anssi; Heino, Mikko; Rijnsdorp, Adriaan D; Dieckmann, Ulf

2014-01-01

Managing fisheries resources to maintain healthy ecosystems is one of the main goals of the ecosystem approach to fisheries (EAF). While a number of international treaties call for the implementation of EAF, there are still gaps in the underlying methodology. One aspect that has received substantial scientific attention recently is fisheries-induced evolution (FIE). Increasing evidence indicates that intensive fishing has the potential to exert strong directional selection on life-history traits, behaviour, physiology, and morphology of exploited fish. Of particular concern is that reversing evolutionary responses to fishing can be much more difficult than reversing demographic or phenotypically plastic responses. Furthermore, like climate change, multiple agents cause FIE, with effects accumulating over time. Consequently, FIE may alter the utility derived from fish stocks, which in turn can modify the monetary value living aquatic resources provide to society. Quantifying and predicting the evolutionary effects of fishing is therefore important for both ecological and economic reasons. An important reason this is not happening is the lack of an appropriate assessment framework. We therefore describe the evolutionary impact assessment (EvoIA) as a structured approach for assessing the evolutionary consequences of fishing and evaluating the predicted evolutionary outcomes of alternative management options. EvoIA can contribute to EAF by clarifying how evolution may alter stock properties and ecological relations, support the precautionary approach to fisheries management by addressing a previously overlooked source of uncertainty and risk, and thus contribute to sustainable fisheries. PMID:26430388

Unravelling ecosystem functions at the Amazonia-Cerrado transition: II. Carbon stocks and CO2 soil efflux in cerradão forest undergoing ecological succession

NASA Astrophysics Data System (ADS)

Peixoto, Karine S.; Marimon-Junior, Ben Hur; Marimon, Beatriz S.; Elias, Fernando; de Farias, Josenilton; Freitag, Renata; Mews, Henrique A.; das Neves, Eder C.; Prestes, Nayane Cristina C. S.; Malhi, Yadvinder

2017-07-01

The transition region between two major South American biomes, the Amazon forest and the Cerrado (Brazilian savanna), has been substantially converted into human-modified ecosystems. Nevertheless, the recovery dynamics of ecosystem functions in this important zone of (ecological) tension (ZOT) remain poorly understood. In this study, we compared two areas of cerradão (a forest-woodland of the Brazilian savanna; Portuguese augmentative of cerrado), one in secondary succession (SC) and one adjacent and well preserved (PC), to test whether the ecosystem functions lost after conversion to pasture were restored after 22 years of regeneration. We tested the hypothesis that the increase in annual aboveground biomass in the SC would be greater than that in the PC because of anticipated successional gains. We also investigated soil CO2 efflux, litter layer content, and fine root biomass in both the SC and PC. In terms of biomass recovery our hypothesis was not supported: the biomass did not increase in the successional area over the study period, which suggested limited capacity for recovery in this key ecosystem compartment. By contrast, the structure and function of the litter layer and root mat were largely reconstituted in the secondary vegetation. Overall, we provide evidence that 22 years of secondary succession were not sufficient for these short and open forests (e.g., cerradão) in the ZOT to recover ecosystem functions to the levels observed in preserved vegetation of identical physiognomy.

An overview of ecological monitoring based on geographic information system (GIS) and remote sensing (RS) technology in China

NASA Astrophysics Data System (ADS)

Zhang, Jing; Zhang, Jia; Du, Xiangyang; Kang, Hou; Qiao, Minjuan

2017-11-01

Due to the rapid development of human economy and society, the resulting ecological problems are becoming more and more prominent, and the dynamic monitoring of the various elements in the ecosystem has become the focus of the current research. For the complex structure and function of the ecological environment monitoring, advanced technical means should be adopted. With the development of spatial information technology, the ecological monitoring technology based on GIS and RS is becoming more and more perfect, and spatial analysis will play an important role in the field of environmental protection. Based on the GIS and RS technology, this paper analyzes the general centralized ecological monitoring model, and makes an objective analysis of the current ecological monitoring trend of China. These are important for the protection and management of ecological environment in China.

Structured copolymers and their use as absorbents, gels and carriers of metal ions

DOEpatents

Hedstrand, David M.; Helmer, Bradley J.; Tomalia, Donald A.

1996-01-01

Dense star polymers or dendrimers having a highly branched interior structure capable of associating or chelating with metal ions are modified by capping with a hydrophobic group capable of providing a hydrophobic outer shell. The modified dendrimers are useful for dispersing metal ions in a non-aqueous polymer matrix. Also dense star polymers or dendrimers having a highly branched hydrophilic interior structure are modified by capping with a hydrophobic group capable of providing a hydrophobic outer shell, which modified polymers are useful as gels and surfactants.

Structured copolymers and their use as absorbents, gels and carriers of metal ions

DOEpatents

Hedstrand, D.M.; Helmer, B.J.; Tomalia, D.A.

1996-10-01

Dense star polymers or dendrimers having a highly branched interior structure capable of associating or chelating with metal ions are modified by capping with a hydrophobic group capable of providing a hydrophobic outer shell. The modified dendrimers are useful for dispersing metal ions in a non-aqueous polymer matrix. Also dense star polymers or dendrimers having a highly branched hydrophilic interior structure are modified by capping with a hydrophobic group capable of providing a hydrophobic outer shell, which modified polymers are useful as gels and surfactants.

Beech cupules as keystone structures for soil fauna.

PubMed

Melguizo-Ruiz, Nereida; Jiménez-Navarro, Gerardo; Moya-Laraño, Jordi

2016-01-01

Facilitative or positive interactions are ubiquitous in nature and play a fundamental role in the configuration of ecological communities. In particular, habitat modification and niche construction, in which one organism locally modifies abiotic conditions and favours other organisms by buffering the effects of adverse environmental factors, are among the most relevant facilitative interactions. In line with this, 'keystone structures', which provide resources, refuge, or advantageous services decisive for other species, may allow the coexistence of various species and thus considerably contribute to diversity maintenance. Beech cupules are woody husks harbouring beech fruits that remain in the forest soil for relatively long periods of time. In this study, we explored the potential role of these cupules in the distribution and maintenance of the soil fauna inhabiting the leaf litter layer. We experimentally manipulated cupule availability and soil moisture in the field to determine if such structures are limiting and can provide moist shelter to soil animals during drought periods, contributing to minimize desiccation risks. We measured invertebrate abundances inside relative to outside the cupules, total abundances in the leaf litter and animal body sizes, in both dry and wet experimental plots. We found that these structures are preferentially used by the most abundant groups of smaller soil animals-springtails, mites and enchytraeids-during droughts. Moreover, beech cupules can be limiting, as an increase in use was found with higher cupule densities, and are important resources for many small soil invertebrates, driving the spatial structure of the soil community and promoting higher densities in the leaf litter, probably through an increase in habitat heterogeneity. We propose that fruit woody structures should be considered 'keystone structures' that contribute to soil community maintenance. Therefore, beech trees may indirectly facilitate soil fauna activities through their decaying fruit husks, hence acting as ecosystem engineers.

Ecological guild and enzyme activities of rhizosphere soil microbial communities associated with Bt-maize cultivation under field conditions in North West Province of South Africa.

PubMed

van Wyk, Deidré A B; Adeleke, Rasheed; Rhode, Owen H J; Bezuidenhout, Carlos C; Mienie, Charlotte

2017-09-01

Insecticidal proteins expressed by genetically modified Bt maize may alter the enzymatic and microbial communities associated with rhizosphere soil. This study investigated the structure and enzymatic activity of rhizosphere soil microbial communities associated with field grown Bt and non-Bt maize. Rhizosphere soil samples were collected from Bt and non-Bt fields under dryland and irrigated conditions. Samples were subjected to chemical tests, enzyme analyses, and next generation sequencing. Results showed that nitrate and phosphorus concentrations were significantly higher in non-Bt maize dryland soils, while organic carbon was significantly higher in non-Bt maize irrigated field soil. Acid phosphatase and β-glucosidase activities were significantly reduced in soils under Bt maize cultivation. The species diversity differed between fields and Bt and non-Bt maize soils. Results revealed that Actinobacteria, Proteobacteria, and Acidobacteria were the dominant phyla present in these soils. Redundancy analyses indicated that some chemical properties and enzyme activities could explain differences in bacterial community structures. Variances existed in microbial community structures between Bt and non-Bt maize fields. There were also differences between the chemical and biochemical properties of rhizosphere soils under Bt and non-Bt maize cultivation. These differences could be related to agricultural practices and cultivar type. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Ecology of Seamounts: Structure, Function, and Human Impacts

NASA Astrophysics Data System (ADS)

Clark, Malcolm R.; Rowden, Ashley A.; Schlacher, Thomas; Williams, Alan; Consalvey, Mireille; Stocks, Karen I.; Rogers, Alex D.; O'Hara, Timothy D.; White, Martin; Shank, Timothy M.; Hall-Spencer, Jason M.

2010-01-01

In this review of seamount ecology, we address a number of key scientific issues concerning the structure and function of benthic communities, human impacts, and seamount management and conservation. We consider whether community composition and diversity differ between seamounts and continental slopes, how important dispersal capabilities are in seamount connectivity, what environmental factors drive species composition and diversity, whether seamounts are centers of enhanced biological productivity, and whether they have unique trophic architecture. We discuss how vulnerable seamount communities are to fishing and mining, and how we can balance exploitation of resources and conservation of habitat. Despite considerable advances in recent years, there remain many questions about seamount ecosystems that need closer integration of molecular, oceanographic, and ecological research.

Regulatory science requirements of labeling of genetically modified food.

PubMed

Moghissi, A Alan; Jaeger, Lisa M; Shafei, Dania; Bloom, Lindsey L

2018-05-01

This paper provides an overview of the evolution of food labeling in the USA. It briefly describes the three phases of agricultural development consisting of naturally occurring, cross-bred, and genetically engineered, edited or modified crops, otherwise known as Genetically Modified Organisms (GMO). It uses the Best Available Regulatory Science (BARS) and Metrics for Evaluation of Regulatory Science Claims (MERSC) to evaluate the scientific validity of claims applicable to GMO and the Best Available Public Information (BAPI) to evaluate the pronouncements by public media and others. Subsequently claims on health risk, ecological risk, consumer choice, and corporate greed are evaluated based on BARS/MERSC and BAPI. The paper concludes by suggesting that labeling of food containing GMO should consider the consumer's choice, such as the food used by those who desire kosher and halal food. Furthermore, the consumer choice is already met by the exclusion of GMO in organic food.

Pathogen survival trajectories: an eco-environmental approach to the modeling of human campylobacteriosis ecology.

PubMed Central

Skelly, Chris; Weinstein, Phil

2003-01-01

Campylobacteriosis, like many human diseases, has its own ecology in which the propagation of human infection and disease depends on pathogen survival and finding new hosts in order to replicate and sustain the pathogen population. The complexity of this process, a process common to other enteric pathogens, has hampered control efforts. Many unknowns remain, resulting in a poorly understood disease ecology. To provide structure to these unknowns and help direct further research and intervention, we propose an eco-environmental modeling approach for campylobacteriosis. This modeling approach follows the pathogen population as it moves through the environments that define the physical structure of its ecology. In this paper, we term the ecologic processes and environments through which these populations move "pathogen survival trajectories." Although such a modeling approach could have veterinary applications, our emphasis is on human campylobacteriosis and focuses on human exposures to Campylobacter through feces, food, and aquatic environments. The pathogen survival trajectories that lead to human exposure include ecologic filters that limit population size, e.g., cooking food to kill Campylobacter. Environmental factors that influence the size of the pathogen reservoirs include temperature, nutrient availability, and moisture availability during the period of time the pathogen population is moving through the environment between infected and susceptible hosts. We anticipate that the modeling approach proposed here will work symbiotically with traditional epidemiologic and microbiologic research to help guide and evaluate the acquisition of new knowledge about the ecology, eventual intervention, and control of campylobacteriosis. PMID:12515674

Disturbed island ecology.

PubMed

Whittaker, R J

1995-10-01

The natural occurrence of significant disturbances to the operation of insular ecosystems has tended to be downplayed in the development of island ecological theory. Despite the importance of events such as Hurricane Hugo, which in 1989 affected islands in the Caribbean, islands that are disturbed tend to be viewed as deviants from the `true path' described by equilibrium models. However, particularly with organisms of long generation times, it is questionable whether such models are applicable. This may be as important for wildlife managers to take account of as for theorists. Disturbance regime should be incorporated into island ecological models alongside other ecological factors structuring colonization patterns and turnover.

Promoting biodiversity values of small forest patches in agricultural landscapes: Ecological drivers and social demand.

PubMed

Varela, Elsa; Verheyen, Kris; Valdés, Alicia; Soliño, Mario; Jacobsen, Jette B; De Smedt, Pallieter; Ehrmann, Steffen; Gärtner, Stefanie; Górriz, Elena; Decocq, Guillaume

2018-04-01

Small forest patches embedded in agricultural (and peri-urban) landscapes in Western Europe play a key role for biodiversity conservation with a recognized capacity of delivering a wide suite of ecosystem services. Measures aimed to preserve these patches should be both socially desirable and ecologically effective. This study presents a joint ecologic and economic assessment conducted on small forest patches in Flanders (Belgium) and Picardie (N France). In each study region, two contrasted types of agricultural landscapes were selected. Open field (OF) and Bocage (B) landscapes are distinguished by the intensity of their usage and higher connectivity in the B landscapes. The social demand for enhancing biodiversity and forest structure diversity as well as for increasing the forest area at the expenses of agricultural land is estimated through an economic valuation survey. These results are compared with the outcomes of an ecological survey where the influence of structural features of the forest patches on the associated herbaceous diversity is assessed. The ecological and economic surveys show contrasting results; increasing tree species richness is ecologically more important for herbaceous diversity in the patch, but both tree species richness and herbaceous diversity obtain insignificant willingness to pay estimates. Furthermore, although respondents prefer the proposed changes to take place in the region where they live, we find out that social preferences and ecological effectiveness do differ between landscapes that represent different intensities of land use. Dwellers where the landscape is perceived as more "degraded" attach more value to diversity enhancement, suggesting a prioritization of initiatives in these area. In contrast, the ecological analyses show that prioritizing the protection and enhancement of the relatively better-off areas is more ecologically effective. Our study calls for a balance between ecological effectiveness and welfare benefits, suggesting that cost effectiveness studies should consider these approaches jointly. Copyright © 2017 Elsevier B.V. All rights reserved.

Meta-ecosystem dynamics and functioning on finite spatial networks

PubMed Central

Marleau, Justin N.; Guichard, Frédéric; Loreau, Michel

2014-01-01

The addition of spatial structure to ecological concepts and theories has spurred integration between sub-disciplines within ecology, including community and ecosystem ecology. However, the complexity of spatial models limits their implementation to idealized, regular landscapes. We present a model meta-ecosystem with finite and irregular spatial structure consisting of local nutrient–autotrophs–herbivores ecosystems connected through spatial flows of materials and organisms. We study the effect of spatial flows on stability and ecosystem functions, and provide simple metrics of connectivity that can predict these effects. Our results show that high rates of nutrient and herbivore movement can destabilize local ecosystem dynamics, leading to spatially heterogeneous equilibria or oscillations across the meta-ecosystem, with generally increased meta-ecosystem primary and secondary production. However, the onset and the spatial scale of these emergent dynamics depend heavily on the spatial structure of the meta-ecosystem and on the relative movement rate of the autotrophs. We show how this strong dependence on finite spatial structure eludes commonly used metrics of connectivity, but can be predicted by the eigenvalues and eigenvectors of the connectivity matrix that describe the spatial structure and scale. Our study indicates the need to consider finite-size ecosystems in meta-ecosystem theory. PMID:24403323

Air Quality Cumulative Effects Assessment for U.S. Air Force Bases.

DTIC Science & Technology

1998-01-29

forecasted activities. Consideration of multimedia effects and transmedia impacts is important, however, in CEA. Any quantification method developed...substantive areas, such as water quality, ecology, planing, archeology , and landscape architecture? 9. Are there public concerns due to the impact risks of...methods developed for CEA should consider multimedia effects and transmedia impacts. Portions of this research can be used, or modified, to address other

Physical and biological responses to an alternative removal strategy of a moderate-sized dam in Washington, USA.

Treesearch

Shannon Claeson; B. Coffin

2015-01-01

Dam removal is an increasingly practised river restoration technique, and ecological responses vary with watershed, dam and reservoir properties, and removal strategies. Moderate-sized dams, like Hemlock Dam (7.9m tall and 56m wide), are large enough that removal effects could be significant, but small enough that mitigation may be possible through a modified dam...

Trombiculiasis: not only a matter of animals!

PubMed

Guarneri, Claudio; Chokoeva, Anastasiya Atanasova; Wollina, Uwe; Lotti, Torello; Tchernev, Georgi

2017-03-01

Trombiculiasis represents a striking emerging infestation in humans. In fact, modified lifestyles and easy and quick traveling around the globe, together with the altered ecology and habits of the parasite Neotrombicula autumnalis, make this original epizoonosis an extraordinary example of synanthropic dermatosis. We present an additional clinical image of this unusual parasite transmission from animals to humans occurring in a trekker in Calabria, Italy.

Ecological risk caused by land use change in the coastal zone: a case study in the Yellow River Delta High-Efficiency Ecological Economic Zone

NASA Astrophysics Data System (ADS)

Di, X. H.; Wang, Y. D.; Hou, X. Y.

2014-03-01

China's coastal zone plays an important role in ecological services production and social-economic development; however, extensive and intensive land resource utilization and land use change have lead to high ecological risk in this area during last decade. Regional ecological risk assessment can provide fundamental knowledge and scientific basis for better understanding of the relationship between regional landscape ecosystem and human activities or climate changes, facilitating the optimization strategy of land use structure and improving the ecological risk prevention capability. In this paper, the Yellow River Delta High-Efficiency Ecological Economic Zone is selected as the study site, which is undergoing a new round of coastal zone exploitation and has endured substantial land use change in the past decade. Land use maps of 2000, 2005 and 2010 were generated based on Landsat images by visual interpretation method, and the ecological risk index was then calculated. The index was 0.3314, 0.3461 and 0.3176 in 2000, 2005 and 2010 respectively, which showed a positive transition of regional ecological risk in 2005.

Changes in composition, ecology and structure of high-mountain vegetation: a re-visitation study over 42 years.

PubMed

Evangelista, Alberto; Frate, Ludovico; Carranza, Maria Laura; Attorre, Fabio; Pelino, Giovanni; Stanisci, Angela

2016-01-27

High-mountain ecosystems are increasingly threatened by climate change, causing biodiversity loss, habitat degradation and landscape modifications. However, very few detailed studies have focussed on plant biodiversity in the high mountains of the Mediterranean. In this study, we investigated the long-term changes that have occurred in the composition, structure and ecology of high-mountain vegetation in the central Apennines (Majella) over the last 42 years. We performed a re-visitation study, using historical and newly collected vegetation data to explore which ecological and structural features have been the most successful in coping with climatic changes. Vegetation changes were analysed by comparing geo-referenced phytosociological relevés collected in high-mountain habitats (dolines, gentle slopes and ridges) on the Majella massif in 1972 and in 2014. Composition analysis was performed by detrended correspondence analysis, followed by an analysis of similarities for statistical significance assessment and by similarity percentage procedure (SIMPER) for identifying which species indicate temporal changes. Changes in ecological and structural indicators were analysed by a permutational multivariate analysis of variance, followed by a post hoc comparison. Over the last 42 years, clear floristic changes and significant ecological and structural variations occurred. We observed a significant increase in the thermophilic and mesonitrophilic plant species and an increment in the frequencies of hemicryptophytes. This re-visitation study in the Apennines agrees with observations in other alpine ecosystems, providing new insights for a better understanding of the effects of global change on Mediterranean high-mountain biodiversity. The observed changes in floristic composition, the thermophilization process and the shift towards a more nutrient-demanding vegetation are likely attributable to the combined effect of higher temperatures and the increase in soil nutrients triggered by global change. The re-visitation approach adopted herein represents a powerful tool for studying climate-related changes in sensitive high-mountain habitats. Published by Oxford University Press on behalf of the Annals of Botany Company.

Population Genetic Analysis of Streptomyces albidoflavus Reveals Habitat Barriers to Homologous Recombination in the Diversification of Streptomycetes

PubMed Central

Cheng, Kun; Rong, Xiaoying; Pinto-Tomás, Adrián A.; Fernández-Villalobos, Marcela; Murillo-Cruz, Catalina

2014-01-01

Examining the population structure and the influence of recombination and ecology on microbial populations makes great sense for understanding microbial evolution and speciation. Streptomycetes are a diverse group of bacteria that are widely distributed in nature and a rich source of useful bioactive compounds; however, they are rarely subjected to population genetic investigations. In this study, we applied a five-gene-based multilocus sequence analysis (MLSA) scheme to 41 strains of Streptomyces albidoflavus derived from diverse sources, mainly insects, sea, and soil. Frequent recombination was detected in S. albidoflavus, supported by multiple lines of evidence from the pairwise homoplasy index (Φw) test, phylogenetic discordance, the Shimodaira-Hasegawa (SH) test, and network analysis, underpinning the predominance of homologous recombination within Streptomyces species. A strong habitat signal was also observed in both phylogenetic and Structure 2.3.3 analyses, indicating the importance of ecological difference in shaping the population structure. Moreover, all three habitat-associated groups, particularly the entomic group, demonstrated significantly reduced levels of gene flow with one another, generally revealing habitat barriers to recombination. Therefore, a combined effect of homologous recombination and ecology is inferred for S. albidoflavus, where dynamic evolution is at least partly balanced by the extent that differential distributions of strains among habitats limit genetic exchange. Our study stresses the significance of ecology in microbial speciation and reveals the coexistence of homologous recombination and ecological divergence in the evolution of streptomycetes. PMID:25416769

Structural and functional changes of soft-bottom ecosystems in northern fjords invaded by the red king crab (Paralithodes camtschaticus)

NASA Astrophysics Data System (ADS)

Oug, Eivind; Sundet, Jan H.; Cochrane, Sabine K. J.

2018-04-01

The red king crab invaded Norwegian coastal waters in the early 1990s after having been introduced from the northern Pacific to the Russian Barents Sea coast. The crab stock increased rapidly in NE northern Norway in the latter half of the 1990s, and since 2002 there has been a commercial fishery in the eastern invaded areas. The crab is an active predator on benthic fauna especially feeding in deep soft-bottom environments. The present study is a follow-up of previous studies (2007-09) to assess the effects of the king crab predation on soft bottom species composition, ecological functioning and sediment quality. Macroinfauna (> 1 mm) was investigated in three fjord areas in the Varanger region with low, moderate and very high crab abundances, respectively. Compared with data from 1994, most benthic species were markedly reduced in abundance, in particular non-moving burrowing and tube-dwelling polychaetes, bivalves and echinoderms. However, a few species appeared to recover from 2007-09 to 2012. Changes in ecological functioning were assessed using 'biological traits analysis (BTA)'. Following the crab invasion there was a relative reduction of suspension and surface deposit feeding species, an increase in mobile and predatory organisms and an increase in those with planktotrophic larval development. From low to high crab abundances functioning changed from tube-building, deep deposit feeding and fairly large size to free-living, shallow burrowing and rather small size. With regard to sediment reworking, downward and upward conveyors were reduced whereas surficial modifiers increased. The changes imply that sediment biomixing and bioirrigation were reduced leading to a degraded sedimentary environment. It is suggested that establishing relationships between ecosystem functioning and crab abundances may form the basis for estimating ecological costs of the crab invasion. Such knowledge is important for managing the crab in the Barents Sea area being both a non-indigenous species affecting native ecosystems as well as a valuable resource for commercial fishery.

Burrow characteristics of the mud shrimp Austinogebia edulis, an ecological engineer causing sediment modification of a tidal flat

PubMed Central

Das, Shagnika; Tseng, Li-Chun; Wang, Lan

2017-01-01

The mud shrimp Austinogebia edulis, being abundant in the intertidal zone of western Taiwan, constructs deep burrows (>1 m). This study highlights the potential of mud shrimps to modify sediment characteristics of the tidal flat by its burrowing behavior. We studied the structure of the burrow wall, compared the difference in the sediment composition of the burrow and the background sediment, and compared the organic content inside the burrow wall. This study was carried out from September 2015 to November 2016 in three areas of the western coast of Taiwan, namely Shengang, Hanbow, and Wangong. The present study found significant differences between burrow wall and the burrow lumen. The diameter of the burrow wall was double as wide as the inner burrow lumen at the opening and gradually increased to 10 times of the burrow lumen at 30 cm depth. The burrow wall of A. edulis showed low permeability and increased the sheer strength. Statistically, a significant difference was noticed in the comparison between the sediment composition of the burrow wall and the background (p < 0.05, Student’s t-test). An accumulation of 3.63 for fine sand (t = -5.22, p < 0.001, fine sand) and 9 for clay (t = -25.01, p < 0.001, clay) was found in the upper burrow wall of A. edulis. This indicated that they somehow chose finer particles to build burrows. This will gradually change the sediment distribution—vertically and horizontally. The burrow wall consisted of a 24 times higher organic matter content than one individual of mud shrimp. The burrow may provide organic material as a potential food source. The mud shrimp thus transforms the sediment characteristics as an ecological engineer, which is expected to have a significant ecological impact on the ecosystem. PMID:29236717

Invasive ants compete with and modify the trophic ecology of hermit crabs on tropical islands.

PubMed

McNatty, Alice; Abbott, Kirsti L; Lester, Philip J

2009-05-01

Invasive species can dramatically alter trophic interactions. Predation is the predominant trophic interaction generally considered to be responsible for ecological change after invasion. In contrast, how frequently competition from invasive species contributes to the decline of native species remains controversial. Here, we demonstrate how the trophic ecology of the remote atoll nation of Tokelau is changing due to competition between invasive ants (Anoplolepis gracilipes) and native terrestrial hermit crabs (Coenobita spp.) for carrion. A significant negative correlation was observed between A. gracilipes and hermit crab abundance. On islands with A. gracilipes, crabs were generally restricted to the periphery of invaded islands. Very few hermit crabs were found in central areas of these islands where A. gracilipes abundances were highest. Ant exclusion experiments demonstrated that changes in the abundance and distribution of hermit crabs on Tokelau are a result of competition. The ants did not kill the hermit crabs. Rather, when highly abundant, A. gracilipes attacked crabs by spraying acid and drove crabs away from carrion resources. Analysis of naturally occurring N and C isotopes suggests that the ants are effectively lowering the trophic level of crabs. According to delta(15) N values, hermit crabs have a relatively high trophic level on islands where A. gracilipes have not invaded. In contrast, where these ants have invaded we observed a significant decrease in delta(15) N for all crab species. This result concurs with our experiment in suggesting long-term exclusion from carrion resources, driving co-occurring crabs towards a more herbivorous diet. Changes in hermit crab abundance or distribution may have major ramifications for the stability of plant communities. Because A. gracilipes have invaded many tropical islands where the predominant scavengers are hermit crabs, we consider that their competitive effects are likely to be more prominent in structuring communities than predation.

A Practical Probabilistic Graphical Modeling Tool for Weighing Ecological Risk-Based Evidence

EPA Science Inventory

Past weight-of-evidence frameworks for adverse ecological effects have provided soft-scoring procedures for judgments based on the quality and measured attributes of evidence. Here, we provide a flexible probabilistic structure for weighing and integrating lines of evidence for e...

A unified model explains commonness and rarity on coral reefs.

PubMed

Connolly, Sean R; Hughes, Terry P; Bellwood, David R

2017-04-01

Abundance patterns in ecological communities have important implications for biodiversity maintenance and ecosystem functioning. However, ecological theory has been largely unsuccessful at capturing multiple macroecological abundance patterns simultaneously. Here, we propose a parsimonious model that unifies widespread ecological relationships involving local aggregation, species-abundance distributions, and species associations, and we test this model against the metacommunity structure of reef-building corals and coral reef fishes across the western and central Pacific. For both corals and fishes, the unified model simultaneously captures extremely well local species-abundance distributions, interspecific variation in the strength of spatial aggregation, patterns of community similarity, species accumulation, and regional species richness, performing far better than alternative models also examined here and in previous work on coral reefs. Our approach contributes to the development of synthetic theory for large-scale patterns of community structure in nature, and to addressing ongoing challenges in biodiversity conservation at macroecological scales. © 2017 The Authors. Ecology Letters published by CNRS and John Wiley & Sons Ltd.

A global meta-analysis on the ecological drivers of forest restoration success

PubMed Central

Crouzeilles, Renato; Curran, Michael; Ferreira, Mariana S.; Lindenmayer, David B.; Grelle, Carlos E. V.; Rey Benayas, José M.

2016-01-01

Two billion ha have been identified globally for forest restoration. Our meta-analysis encompassing 221 study landscapes worldwide reveals forest restoration enhances biodiversity by 15–84% and vegetation structure by 36–77%, compared with degraded ecosystems. For the first time, we identify the main ecological drivers of forest restoration success (defined as a return to a reference condition, that is, old-growth forest) at both the local and landscape scale. These are as follows: the time elapsed since restoration began, disturbance type and landscape context. The time elapsed since restoration began strongly drives restoration success in secondary forests, but not in selectively logged forests (which are more ecologically similar to reference systems). Landscape restoration will be most successful when previous disturbance is less intensive and habitat is less fragmented in the landscape. Restoration does not result in full recovery of biodiversity and vegetation structure, but can complement old-growth forests if there is sufficient time for ecological succession. PMID:27193756

Human effects on ecological connectivity in aquatic ecosystems: Integrating scientific approaches to support management and mitigation.

PubMed

Crook, David A; Lowe, Winsor H; Allendorf, Frederick W; Erős, Tibor; Finn, Debra S; Gillanders, Bronwyn M; Hadwen, Wade L; Harrod, Chris; Hermoso, Virgilio; Jennings, Simon; Kilada, Raouf W; Nagelkerken, Ivan; Hansen, Michael M; Page, Timothy J; Riginos, Cynthia; Fry, Brian; Hughes, Jane M

2015-11-15

Understanding the drivers and implications of anthropogenic disturbance of ecological connectivity is a key concern for the conservation of biodiversity and ecosystem processes. Here, we review human activities that affect the movements and dispersal of aquatic organisms, including damming of rivers, river regulation, habitat loss and alteration, human-assisted dispersal of organisms and climate change. Using a series of case studies, we show that the insight needed to understand the nature and implications of connectivity, and to underpin conservation and management, is best achieved via data synthesis from multiple analytical approaches. We identify four key knowledge requirements for progressing our understanding of the effects of anthropogenic impacts on ecological connectivity: autecology; population structure; movement characteristics; and environmental tolerance/phenotypic plasticity. Structuring empirical research around these four broad data requirements, and using this information to parameterise appropriate models and develop management approaches, will allow for mitigation of the effects of anthropogenic disturbance on ecological connectivity in aquatic ecosystems. Copyright © 2015 Elsevier B.V. All rights reserved.

Some observations on the use of discriminant analysis in ecology

USGS Publications Warehouse

Williams, B.K.

1983-01-01

The application of discriminant analysis in ecological investigations is discussed. The appropriate statistical assumptions for discriminant analysis are illustrated, and both classification and group separation approaches are outlined. Three assumptions that are crucial in ecological studies are discussed at length, and the consequences of their violation are developed. These assumptions are: equality of dispersions, identifiability of prior probabilities, and precise and accurate estimation of means and dispersions. The use of discriminant functions for purposes of interpreting ecological relationships is also discussed. It is suggested that the common practice of imputing ecological 'meaning' to the signs and magnitudes of coefficients be replaced by an assessment of 'structure coefficients.' Finally, the potential and limitations of representation of data in canonical space are considered, and some cautionary points are made concerning ecological interpretation of patterns in canonical space.

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.

Population genetic structure of gray wolves (Canis lupus) in a marine archipelago suggests island-mainland differentiation consistent with dietary niche.

PubMed

Stronen, Astrid V; Navid, Erin L; Quinn, Michael S; Paquet, Paul C; Bryan, Heather M; Darimont, Christopher T

2014-06-10

Emerging evidence suggests that ecological heterogeneity across space can influence the genetic structure of populations, including that of long-distance dispersers such as large carnivores. On the central coast of British Columbia, Canada, wolf (Canis lupus L., 1758) dietary niche and parasite prevalence data indicate strong ecological divergence between marine-oriented wolves inhabiting islands and individuals on the coastal mainland that interact primarily with terrestrial prey. Local holders of traditional ecological knowledge, who distinguish between mainland and island wolf forms, also informed our hypothesis that genetic differentiation might occur between wolves from these adjacent environments. We used microsatellite genetic markers to examine data obtained from wolf faecal samples. Our results from 116 individuals suggest the presence of a genetic cline between mainland and island wolves. This pattern occurs despite field observations that individuals easily traverse the 30 km wide study area and swim up to 13 km among landmasses in the region. Natal habitat-biased dispersal (i.e., the preference for dispersal into familiar ecological environments) might contribute to genetic differentiation. Accordingly, this working hypothesis presents an exciting avenue for future research where marine resources or other components of ecological heterogeneity are present.

Brachiopod faunas after the end Ordovician mass extinction from South China: Testing ecological change through a major taxonomic crisis

NASA Astrophysics Data System (ADS)

Huang, Bing; Harper, David A. T.; Rong, Jiayu; Zhan, Renbin

2017-05-01

Classification of extinction events and their severity is generally based on taxonomic counts. The ecological impacts of such events have been categorized and prioritized but rarely tested with empirical data. The ecology of the end Ordovician extinction and subsequent biotic recovery is tracked through abundant and diverse brachiopod faunas in South China. The spatial and temporal ranges of some 6500 identified specimens, from 10 collections derived from six localities were investigated by network and cluster analyses, nonmetric multidimensional scaling and a species abundance model. Depth zonations and structure of brachiopod assemblages along an onshore-offshore gradient in the late Katian were similar to those in the latest Ordovician-earliest Silurian (post-extinction fauna). Within this ecological framework, deeper-water faunas are partly replaced by new taxa; siliciclastic substrates continued to be dominated by the more 'Ordovician' orthides and strophomenides, shallow-water carbonate environments hosted atrypides, athyridides and pentamerides, with the more typical Ordovician brachiopod fauna continuing to dominate until the late Rhuddanian. The end Ordovician extinctions tested the resilience of the brachiopod fauna without damage to its overall ecological structure; that commenced later at the end of the Rhuddanian.

Preliminary results on the control of Aedes spp. in a remote Guatemalan community vulnerable to dengue, chikungunya and Zika virus: community participation and use of low-cost ecological ovillantas for mosquito control

PubMed Central

Ulibarri, Gerard; Betanzos, Angel; Betanzos, Mireya; Rojas, Juan Jacobo

2017-01-01

Objective: To study the effectiveness of an integrated intervention of health worker training, a low-cost ecological mosquito ovitrap, and community engagement on Aedes spp. mosquito control over 10 months in 2015 in an urban remote community in Guatemala at risk of dengue, chikungunya and Zika virus transmission. Methods: We implemented a three-component integrated intervention consisting of: web-based training of local health personnel in vector control, cluster-randomized assignment of an ecological modified ovitrap (ovillantas: ovi=egg, llanta=tire) or standard ovitraps to capture Aedes spp. mosquito eggs (no efforts have been taken to determine the exact Aedes species at this moment), and community engagement to promote participation of community members and health personnel in the understanding and maintenance of ovitraps for mosquito control. The intervention was implemented in local collaboration with Guatemala’s  Ministry of Health’s Vector Control Programme, and in international collaboration with the National Institute of Public Health in Mexico. Findings: Eighty percent of the 25 local health personnel enrolled in the training programme received accreditation of their improved knowledge of vector control. When ovillantas were used in a cluster of ovitraps (several in proximity), significantly more eggs were trapped by  ecological ovillantas than standard ovitraps over the 10 month (42 week) study period (t=5.2577; p<0.05). Repetitive filtering and recycling of the attractant solution (or water) kept the ovillanta clean, free from algae growth. Among both community members and health workers, the levels of knowledge, interest, and participation in community mosquito control and trapping increased. Recommendations for enhancing and sustaining community mosquito control were identified. Conclusion: Our three-component integrated intervention proved beneficial to this remote community at risk of mosquito-borne diseases such as dengue, chikungunya, and Zika. The combination of training of health workers, cluster use of low-cost ecological ovillanta to destroy the second generation of mosquitoes, and community engagement ensured the project met local needs and fostered collaboration and participation of the community, which can help improve sustainability. The ovillanta intervention and methodology may be modified to target other species such as Culex, should it be established that such mosquitoes carry Zika virus in addition to Aedes. PMID:28105304

Uncoupling of microbial community structure and function in decomposing litter across beech forest ecosystems in Central Europe.

PubMed

Purahong, Witoon; Schloter, Michael; Pecyna, Marek J; Kapturska, Danuta; Däumlich, Veronika; Mital, Sanchit; Buscot, François; Hofrichter, Martin; Gutknecht, Jessica L M; Krüger, Dirk

2014-11-12

The widespread paradigm in ecology that community structure determines function has recently been challenged by the high complexity of microbial communities. Here, we investigate the patterns of and connections between microbial community structure and microbially-mediated ecological function across different forest management practices and temporal changes in leaf litter across beech forest ecosystems in Central Europe. Our results clearly indicate distinct pattern of microbial community structure in response to forest management and time. However, those patterns were not reflected when potential enzymatic activities of microbes were measured. We postulate that in our forest ecosystems, a disconnect between microbial community structure and function may be present due to differences between the drivers of microbial growth and those of microbial function.

Ecological limit functions relating fish community response to hydrologic departures of the ecological flow regime in the Tennessee River basin, United States

USGS Publications Warehouse

Knight, Rodney R.; Murphy, Jennifer C.; Wolfe, William J.; Saylor, Charles F.; Wales, Amy K.

2014-01-01

Ecological limit functions relating streamflow and aquatic ecosystems remain elusive despite decades of research. We investigated functional relationships between species richness and changes in streamflow characteristics at 662 fish sampling sites in the Tennessee River basin. Our approach included the following: (1) a brief summary of relevant literature on functional relations between fish and streamflow, (2) the development of ecological limit functions that describe the strongest discernible relationships between fish species richness and streamflow characteristics, (3) the evaluation of proposed definitions of hydrologic reference conditions, and (4) an investigation of the internal structures of wedge-shaped distributions underlying ecological limit functions.Twenty-one ecological limit functions were developed across three ecoregions that relate the species richness of 11 fish groups and departures from hydrologic reference conditions using multivariate and quantile regression methods. Each negatively sloped function is described using up to four streamflow characteristics expressed in terms of cumulative departure from hydrologic reference conditions. Negative slopes indicate increased departure results in decreased species richness.Sites with the highest measured fish species richness generally had near-reference hydrologic conditions for a given ecoregion. Hydrology did not generally differ between sites with the highest and lowest fish species richness, indicating that other environmental factors likely limit species richness at sites with reference hydrology.Use of ecological limit functions to make decisions regarding proposed hydrologic regime changes, although commonly presented as a management tool, is not as straightforward or informative as often assumed. We contend that statistical evaluation of the internal wedge structure below limit functions may provide a probabilistic understanding of how aquatic ecology is influenced by altered hydrology and may serve as the basis for evaluating the potential effect of proposed hydrologic changes.

Quorum sensing is a language of chemical signals and plays an ecological role in algal-bacterial interactions

PubMed Central

Zhou, Jin; Lyu, Yihua; Richlen, Mindy; Anderson, Donald M.; Cai, Zhonghua

2017-01-01

Algae are ubiquitous in the marine environment, and the ways in which they interact with bacteria are of particular interest in marine ecology field. The interactions between primary producers and bacteria impact the physiology of both partners, alter the chemistry of their environment, and shape microbial diversity. Although algal-bacterial interactions are well known and studied, information regarding the chemical-ecological role of this relationship remains limited, particularly with respect to quorum sensing (QS), which is a system of stimuli and response correlated to population density. In the microbial biosphere, QS is pivotal in driving community structure and regulating behavioral ecology, including biofilm formation, virulence, antibiotic resistance, swarming motility, and secondary metabolite production. Many marine habitats, such as the phycosphere, harbour diverse populations of microorganisms and various signal languages (such as QS-based autoinducers). QS-mediated interactions widely influence algal-bacterial symbiotic relationships, which in turn determine community organization, population structure, and ecosystem functioning. Understanding infochemicals-mediated ecological processes may shed light on the symbiotic interactions between algae host and associated microbes. In this review, we summarize current achievements about how QS modulates microbial behavior, affects symbiotic relationships, and regulates phytoplankton chemical ecological processes. Additionally, we present an overview of QS-modulated co-evolutionary relationships between algae and bacterioplankton, and consider the potential applications and future perspectives of QS. PMID:28966438

A tool for assessing ecological status of forest ecosystem

NASA Astrophysics Data System (ADS)

Rahman Kassim, Abd; Afizzul Misman, Muhammad; Azahari Faidi, Mohd; Omar, Hamdan

2016-06-01

Managers and policy makers are beginning to appreciate the value of ecological monitoring of artificially regenerated forest especially in urban areas. With the advent of more advance technology in precision forestry, high resolution remotely sensed data e.g. hyperspectral and LiDAR are becoming available for rapid and precise assessment of the forest condition. An assessment of ecological status of forest ecosystem was developed and tested using FRIM campus forest stand. The forest consisted of three major blocks; the old growth artificially regenerated native species forests, naturally regenerated forest and recent planted forest for commercial timber and other forest products. Our aim is to assess the ecological status and its proximity to the mature old growth artificially regenerated stand. We used airborne LiDAR, orthophoto and thirty field sampling quadrats of 20x20m for ground verification. The parameter assessments were grouped into four broad categories: a. forest community level-composition, structures, function; landscape structures-road network and forest edges. A metric of parameters and rating criteria was introduced as indicators of the forest ecological status. We applied multi-criteria assessment to categorize the ecological status of the forest stand. The paper demonstrates the application of the assessment approach using FRIM campus forest as its first case study. Its potential application to both artificially and naturally regenerated forest in the variety of Malaysian landscape is discussed

Towards the development of multifunctional molecular indicators combining soil biogeochemical and microbiological variables to predict the ecological integrity of silvicultural practices.

PubMed

Peck, Vincent; Quiza, Liliana; Buffet, Jean-Philippe; Khdhiri, Mondher; Durand, Audrey-Anne; Paquette, Alain; Thiffault, Nelson; Messier, Christian; Beaulieu, Nadyre; Guertin, Claude; Constant, Philippe

2016-05-01

The impact of mechanical site preparation (MSP) on soil biogeochemical structure in young larch plantations was investigated. Soil samples were collected in replicated plots comprising simple trenching, double trenching, mounding and inverting site preparation. Unlogged natural mixed forest areas were used as a reference. Analysis of soil nutrients, abundance of bacteria and gas exchanges unveiled no significant difference among the plots. However, inverting site preparation resulted in higher variations of gas exchanges when compared with trenching, mounding and unlogged natural forest. A combination of the biological and physicochemical variables was used to define a multifunctional classification of the soil samples into four distinct groups categorized as a function of their deviation from baseline ecological conditions. According to this classification model, simple trenching was the approach that represented the lowest ecological risk potential at the microsite level. No relationship was observed between MSP method and soil bacterial community structure as assessed by high-throughput sequencing of bacterial 16S rRNA gene; however, indicator genotypes were identified for each multifunctional soil class. This is the first identification of multifunctional molecular indicators for baseline and disturbed ecological conditions in soil, demonstrating the potential of applied microbial ecology to guide silvicultural practices and ecological risk assessment. © 2016 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

Classification and description of world formation types

Treesearch

D. Faber-Langendoen; T. Keeler-Wolf; D. Meidinger; C. Josse; A. Weakley; D. Tart; G. Navarro; B. Hoagland; S. Ponomarenko; G. Fults; Eileen Helmer

2016-01-01

An ecological vegetation classification approach has been developed in which a combination of vegetation attributes (physiognomy, structure, and floristics) and their response to ecological and biogeographic factors are used as the basis for classifying vegetation types. This approach can help support international, national, and subnational classification efforts. The...

A PROCESS FOR SELECTING INDICATORS FOR MONITORING CONDITIONS OF RANGELAND HEALTH (COPY)

EPA Science Inventory

This paper reports on a process for selecting a suite of indicators that, in combination, can be useful in assessing the ecological conditions of rangelands. Conceptual models that depict the structural and functional properties of ecological processes were used to show the linka...

Arctic systems in the Quaternary: Ecological collision, faunal mosaics and the consequences of wobbling climate

USDA-ARS?s Scientific Manuscript database

Climate oscillations and episodic or recurrent processes interact with evolution, ecology and biogeography determining the structure and complex mosaic that is the biosphere. Parasites and parasite-host assemblages, within an expansive environmental matrix determined by climate, are key components...

Spatial-structural analysis of leafless woody riparian vegetation for hydraulic considerations

NASA Astrophysics Data System (ADS)

Weissteiner, Clemens; Jalonen, Johanna; Järvelä, Juha; Rauch, Hans Peter

2013-04-01

Woody riparian vegetation is a vital element of riverine environments. On one hand woody riparian vegetation has to be taken into account from a civil engineering point of view due to boundary shear stress and vegetation drag. On the other hand it has to be considered from a river ecological point of view due to shadowing effects and as a source of organic material for aquatic habitats. In hydrodynamic and hydro-ecological studies the effects of woody riparian vegetation on flow patterns are usually investigated on a very detailed level. On the contrary vegetation elements and their spatial patterns are generally analysed and discussed on the basis of an integral approach measuring for example basal diameters, heights and projected plant areas. For a better understanding of the influence of woody riparian vegetation on turbulent flow and on river ecology, it is essential to record and analyse plant data sets on the same level of quality as for hydrodynamic or hydro-ecologic purposes. As a result of the same scale of the analysis it is possible to incorporate riparian vegetation as a sub-model in the hydraulic analysis. For plant structural components, such as branches on different topological levels it is crucial to record plant geometrical parameters describing the habitus of the plant on branch level. An exact 3D geometrical model of real plants allows for an extraction of various spatial-structural plant parameters. In addition, allometric relationships help to summarize and describe plant traits of riparian vegetation. This paper focuses on the spatial-structural composition of leafless riparia woddy vegetation. Structural and spatial analyses determine detailed geometric properties of the structural components of the plants. Geometrical and topological parameters were recorded with an electro-magnetic scanning device. In total, 23 plants (willows, alders and birches) were analysed in the study. Data were recorded on branch level, which allowed for the development of a 3D geometric plant model. The results are expected to improve knowledge on how the architectural system and allometric relationships of the plants relate to ecological and hydrodynamic properties.

Disturbance and productivity interactions mediate stability of forest composition and structure.

PubMed

O'Connor, Christopher D; Falk, Donald A; Lynch, Ann M; Swetnam, Thomas W; Wilcox, Craig P

2017-04-01

Fire is returning to many conifer-dominated forests where species composition and structure have been altered by fire exclusion. Ecological effects of these fires are influenced strongly by the degree of forest change during the fire-free period. Response of fire-adapted species assemblages to extended fire-free intervals is highly variable, even in communities with similar historical fire regimes. This variability in plant community response to fire exclusion is not well understood; however, ecological mechanisms such as individual species' adaptations to disturbance or competition and underlying site characteristics that facilitate or impede establishment and growth have been proposed as potential drivers of assemblage response. We used spatially explicit dendrochronological reconstruction of tree population dynamics and fire regimes to examine the influence of historical disturbance frequency (a proxy for adaptation to disturbance or competition), and potential site productivity (a proxy for underlying site characteristics) on the stability of forest composition and structure along a continuous ecological gradient of pine, dry mixed-conifer, mesic mixed-conifer, and spruce-fir forests following fire exclusion. While average structural density increased in all forests, species composition was relatively stable in the lowest productivity pine-dominated and highest productivity spruce-fir-dominated sites immediately following fire exclusion and for the next 100 years, suggesting site productivity as a primary control on species composition and structure in forests with very different historical fire regimes. Species composition was least stable on intermediate productivity sites dominated by mixed-conifer forests, shifting from primarily fire-adapted species to competition-adapted, fire-sensitive species within 20 years of fire exclusion. Rapid changes to species composition and stand densities have been interpreted by some as evidence of high-severity fire. We demonstrate that the very different ecological process of fire exclusion can produce similar changes by shifting selective pressures from disturbance-mediated to productivity-mediated controls. Restoring disturbance-adapted species composition and structure to intermediate productivity forests may help to buffer them against projected increasing temperatures, lengthening fire seasons, and more frequent and prolonged moisture stress. Fewer management options are available to promote adaptation in forest assemblages historically constrained by underlying site productivity. © 2016 by the Ecological Society of America.

State infant mortality: an ecologic study to determine modifiable risks and adjusted infant mortality rates.

PubMed

Paul, David A; Mackley, Amy; Locke, Robert G; Stefano, John L; Kroelinger, Charlan

2009-05-01

To determine factors contributing to state infant mortality rates (IMR) and develop an adjusted IMR in the United States for 2001 and 2002. Ecologic study of factors contributing to state IMR. State IMR for 2001 and 2002 were obtained from the United States linked death and birth certificate data from the National Center for Health Statistics. Factors investigated using multivariable linear regression included state racial demographics, ethnicity, state population, median income, education, teen birth rate, proportion of obesity, smoking during pregnancy, diabetes, hypertension, cesarean delivery, prenatal care, health insurance, self-report of mental illness, and number of in-vitro fertilization procedures. Final risk adjusted IMR's were standardized and states were compared with the United States adjusted rates. Models for IMR in individual states in 2001 (r2 = 0.66, P < 0.01) and 2002 (r2 = 0.81, P < 0.01) were tested. African-American race, teen birth rate, and smoking during pregnancy remained independently associated with state infant mortality rates for 2001 and 2002. Ninety five percent confidence intervals (CI) were calculated around the regression lines to model the expected IMR. After adjustment, some states maintained a consistent IMR; for instance, Vermont and New Hampshire remained low, while Delaware and Louisiana remained high. However, other states such as Mississippi, which have traditionally high infant mortality rates, remained within the expected 95% CI for IMR after adjustment indicating confounding affected the initial unadjusted rates. Non-modifiable demographic variables, including the percentage of non-Hispanic African-American and Hispanic populations of the state are major factors contributing to individual variation in state IMR. Race and ethnicity may confound or modify the IMR in states that shifted inside or outside the 95% CI following adjustment. Other factors including smoking during pregnancy and teen birth rate, which are potentially modifiable, significantly contributed to differences in state IMR. State risk adjusted IMR indicate that other factors impact infant mortality after adjustment by race/ethnicity and other risk factors.

The non-linear, interactive effects of population density and climate drive the geographical patterns of waterfowl survival

USGS Publications Warehouse

Zhao, Qing; Boomer, G. Scott; Kendall, William L.

2018-01-01

On-going climate change has major impacts on ecological processes and patterns. Understanding the impacts of climate on the geographical patterns of survival can provide insights to how population dynamics respond to climate change and provide important information for the development of appropriate conservation strategies at regional scales. It is challenging to understand the impacts of climate on survival, however, due to the fact that the non-linear relationship between survival and climate can be modified by density-dependent processes. In this study we extended the Brownie model to partition hunting and non-hunting mortalities and linked non-hunting survival to covariates. We applied this model to four decades (1972–2014) of waterfowl band-recovery, breeding population survey, and precipitation and temperature data covering multiple ecological regions to examine the non-linear, interactive effects of population density and climate on waterfowl non-hunting survival at a regional scale. Our results showed that the non-linear effect of temperature on waterfowl non-hunting survival was modified by breeding population density. The concave relationship between non-hunting survival and temperature suggested that the effects of warming on waterfowl survival might be multifaceted. Furthermore, the relationship between non-hunting survival and temperature was stronger when population density was higher, suggesting that high-density populations may be less buffered against warming than low-density populations. Our study revealed distinct relationships between waterfowl non-hunting survival and climate across and within ecological regions, highlighting the importance of considering different conservation strategies according to region-specific population and climate conditions. Our findings and associated novel modelling approach have wide implications in conservation practice.

Refining area of occupancy to address the modifiable areal unit problem in ecology and conservation.

PubMed

Moat, Justin; Bachman, Steven P; Field, Richard; Boyd, Doreen S

2018-05-23

The 'modifiable areal unit problem' is prevalent across many aspects of spatial analysis within ecology and conservation. The problem is particularly manifest when calculating metrics for extinction risk estimation, for example, area of occupancy (AOO). Although embedded into the International Union for the Conservation of Nature (IUCN) Red List criteria, AOO is often not used or is poorly applied. Here we evaluate new and existing methods for calculating AOO from occurrence records and present a method for determining the minimum AOO using a uniform grid. We evaluate the grid cell shape, grid origin and grid rotation with both real-world and simulated data, reviewing the effects on AOO values, and possible impacts for species already assessed on the IUCN Red List. We show that AOO can vary by up to 80% and a ratio of cells to points of 1:1.21 gives the maximum variation in the number of occupied cells. These findings potentially impact 3% of existing species on the IUCN Red List, as well as species not yet assessed. We show that a new method that combines both grid rotation and moving grid origin gives fast, robust and reproducible results and, in the majority of cases, achieves the minimum AOO. As well as reporting minimum AOO, we outline a confidence interval which should be incorporated into existing tools that support species risk assessment. We also make further recommendations for reporting AOO and other areal measurements within ecology, leading to more robust methods for future species risk assessment. This article is protected by copyright. All rights reserved. © 2018 The Authors. Conservation Biology published by Wiley Periodicals, Inc. on behalf of Society for Conservation Biology.

A review of the endemic Hawaiian Drosophilidae and their host plants

USGS Publications Warehouse

Magnacca, K.N.; Foote, D.; O'Grady, P. M.

2008-01-01

The Hawaiian Drosophilidae is one of the best examples of rapid speciation in nature. Nearly 1,000 species of endemic drosophilids have evolved in situ in Hawaii since a single colonist arrived over 25 million years ago. A number of mechanisms, including ecological adaptation, sexual selection, and geographic isolation, have been proposed to explain the evolution of this hyperdiverse group of species. Here, we examine the known ecological associations of 326 species of endemic Hawaiian Drosophilidae in light of the phylogenetic relationships of these species. Our analysis suggests that the long-accepted belief of strict ecological specialization in this group does not hold for all taxa. While many species have a primary host plant family, females will also oviposit on non-preferred host plant taxa. Host shifting is fairly common in some groups, especially the grimshawi and modified mouthparts species groups of Drosophila, and the Scaptomyza subgenus Elmomyza. Associations with types of substrates (bark, leaves, flowers) are more evolutionarily conserved than associations with host plant families. These data not only give us insight into the role ecology has played in the evolution of this large group, but can help in making decisions about the management of rare and endangered host plants and the insects that rely upon them for survival. Copyright ?? 2008 Magnolia Press.