Does proximity to a mature forest contribute to the seed rain and recovery of an abandoned agriculture area in a semiarid climate?

PubMed

Souza, J T; Ferraz, E M N; Albuquerque, U P; Araújo, E L

2014-07-01

Proximity to forests contributes to the recolonisation of anthropogenic-disturbed areas through seed input. We evaluated the role of proximity to a mature forest in the recolonisation of an agricultural area that has been abandoned for 18 years and is currently a young forest. Seed rain was monitored at fixed distances from the mature forest. The type of surface recolonisation (germination versus resprouting) and the reproductive season were measured in both forests. The majority of plants recolonising the young forest originated from seed germination. Proximity to the mature forest contributed to the seed rain in the young forest; however, 18 years has not provided sufficient time for the recolonisation of 80 species present in the mature forest. Some species shared between forests differed in their fruiting season and seed dispersal. The seed rain had a total species richness of 56, a total density of 2270 seeds·m(-2)·year(−1) and predominance of self- and wind dispersal. A significant reduction in seed rain with increasing distance from the mature forest was observed. The young forest contained 35 species not observed in the mature forest, and the floristic similarity between the two forests was 0.5, indicating that the two forests are floristically distinct. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

Life on the edge: carbon fluxes from wetland to ocean along Alaska's coastal temperate rain forest

Treesearch

Rhonda Mazza; Richard Edwards; David D' Amore

2010-01-01

Acre for acre, streams of the coastal temperate rain forest along the Gulf of Alaska export 36 times as much dissolved organic carbon as the world average. Rain and snow are the great connectors, tightly linking aquatic and terrestrial systems of this region. The freshwater that flushes over and through the forest floor leaches carbon...

Rain Fade Compensation for Ka-Band Communications Satellites

NASA Technical Reports Server (NTRS)

Mitchell, W. Carl; Nguyen, Lan; Dissanayake, Asoka; Markey, Brian; Le, Anh

1997-01-01

This report provides a review and evaluation of rain fade measurement and compensation techniques for Ka-band satellite systems. This report includes a description of and cost estimates for performing three rain fade measurement and compensation experiments. The first experiment deals with rain fade measurement techniques while the second one covers the rain fade compensation techniques. The third experiment addresses a feedback flow control technique for the ABR service (for ATM-based traffic). The following conclusions were observed in this report; a sufficient system signal margin should be allocated for all carriers in a network, that is a fixed clear-sky margin should be typically in the range of 4-5 dB and should be more like 15 dB in the up link for moderate and heavy rain zones; to obtain a higher system margin it is desirable to combine the uplink power control technique with the technique that implements the source information rate and FEC code rate changes resulting in a 4-5 dB increase in the dynamic part of the system margin. The experiments would assess the feasibility of the fade measurements and compensation techniques, and ABR feedback control technique.

Effect of simulated acid rain on the litter decomposition of Quercus acutissima and Pinus massoniana in forest soil microcosms and the relationship with soil enzyme activities.

PubMed

Wang, Congyan; Guo, Peng; Han, Guomin; Feng, Xiaoguang; Zhang, Peng; Tian, Xingjun

2010-06-01

With the continuing increase in human activities, ecologists are increasingly interested in understanding the effects of acid rain on litter decomposition. Two dominant litters were chosen from Zijin Mountain in China: Quercus acutissima from a broad-leaved forest and Pinus massoniana from a coniferous forest. The litters were incubated in microcosms and treated with simulated acid rain (gradient pH levels). During a six-month incubation, changes in chemical composition (i.e., lignin, total carbohydrate, and nitrogen), litter mass losses, soil pH values, and activities of degradative enzymes were determined. Results showed that litter mass losses were depressed after exposure to acid rain and the effects of acid rain on the litter decomposition rates of needles were higher than on those of leaves. Results also revealed that simulated acid rain restrained the activities of cellulase, invertase, nitrate reductase, acid phosphatase, alkaline phosphatase, polyphenol oxidase, and urease, while it enhanced the activities of catalase in most cases during the six-month decomposition process. Catalase and polyphenol oxidase were primarily responsible for litter decomposition in the broad-leaved forest, while invertase, nitrate reductase, and urease were primarily responsible for litter decomposition in the coniferous forest. The results suggest acid rain-restrained litter decomposition may be due to the depressed enzymatic activities. According to the results of this study, soil carbon in subtropical forests would accumulate as a long-term consequence of continued acid rain. This may presumably alter the balance of ecosystem carbon flux, nutrient cycling, and humus formation, which may, in turn, have multiple effects on forest ecosystems. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Natural and near natural tropical forest values

Treesearch

Daniel H. Henning

2011-01-01

This paper identifies and describes some of the values associated with tropical rain forests in their natural and near-natural conditions. Tropical rain forests are moist forests in the humid tropics where temperature and rainfall are high and the dry season is short. These closed (non-logged) and broad-leaved forests are a global resource. Located almost entirely in...

Arbuscular-mycorrhizal networks inhibit Eucalyptus tetrodonta seedlings in rain forest soil microcosms.

PubMed

Janos, David P; Scott, John; Aristizábal, Catalina; Bowman, David M J S

2013-01-01

Eucalyptus tetrodonta, a co-dominant tree species of tropical, northern Australian savannas, does not invade adjacent monsoon rain forest unless the forest is burnt intensely. Such facilitation by fire of seedling establishment is known as the "ashbed effect." Because the ashbed effect might involve disruption of common mycorrhizal networks, we hypothesized that in the absence of fire, intact rain forest arbuscular mycorrhizal (AM) networks inhibit E. tetrodonta seedlings. Although arbuscular mycorrhizas predominate in the rain forest, common tree species of the northern Australian savannas (including adult E. tetrodonta) host ectomycorrhizas. To test our hypothesis, we grew E. tetrodonta and Ceiba pentandra (an AM-responsive species used to confirm treatments) separately in microcosms of ambient or methyl-bromide fumigated rain forest soil with or without severing potential mycorrhizal fungus connections to an AM nurse plant, Litsea glutinosa. As expected, C. pentandra formed mycorrhizas in all treatments but had the most root colonization and grew fastest in ambient soil. E. tetrodonta seedlings also formed AM in all treatments, but severing hyphae in fumigated soil produced the least colonization and the best growth. Three of ten E. tetrodonta seedlings in ambient soil with intact network hyphae died. Because foliar chlorosis was symptomatic of iron deficiency, after 130 days we began to fertilize half the E. tetrodonta seedlings in ambient soil with an iron solution. Iron fertilization completely remedied chlorosis and stimulated leaf growth. Our microcosm results suggest that in intact rain forest, common AM networks mediate belowground competition and AM fungi may exacerbate iron deficiency, thereby enhancing resistance to E. tetrodonta invasion. Common AM networks-previously unrecognized as contributors to the ashbed effect-probably help to maintain the rain forest-savanna boundary.

[Dynamics of Quercus variabilis seed rain and soil seed bank in different habitats on the north slope of Qinling Mountains].

PubMed

Wu, Min; Zhang, Wen-Hui; Zhou, Jian-Yun; Ma, Chuang; Ma, Li-Wei

2011-11-01

In order to explore the dynamics of Quercus variabilis seed rain and soil seed bank in different habitats on the north slope of Qinling Mountains, three kinds of micro-habitats (understory, forest gap, and forest edge) were selected, with the seed rain quantity and quality of Q. variabilis, seed amount and viability in soil seed bank, as well as the seedling development of Q. variabilis studied. The seed rain of Q. variabilis started from mid August, reached the peak in mid September-early October, and ended at the beginning of November, and there existed differences in the dissemination process, occurrence time, and composition of the seed rain among the three micro-habitats. The seed rain had the maximum intensity (39.55 +/- 5.56 seeds x m(-2)) in understory, the seeds had the earliest landing time, the longest lasting duration, and the highest viability in forest gap, and the mature seeds had the largest proportion in forest edge, accounting for 58.7% of the total. From the ending time of seed rain to next August, the total reserve of soil seed bank was the largest in understory and the smallest in forest edge. In the three habitats, the amount of mature and immature seeds, that of seeds eaten by animals, and the seed viability in soil seed bank all decreased with time. In contrast, the number of moldy seeds increased. The seeds were mainly concentrated in litter layer, a few of them were in 0-2 cm soil layer, and few were in 2-5 cm soil layer. The density of the seedlings varied with habitats, being the largest in forest gap, followed by in forest edge, and the least in understory, which suggested that forest gap was more suitable for the seed germination and seedling growth of Q. variabilis, and thus, appropriate thinning should be taken to increase forest gap to provide favorable conditions for the natural regeneration of Q. variabilis forest.

Forest structure and composition in the lower montane rain forest of the Luquillo Mountains, Puerto Rico

Treesearch

Peter L. Weaver

2010-01-01

Six groups of three plots stratified by aspect and topography and varying in elevation were used to sample forest structure and tree species composition within the lower montane rain forest (tabonuco forest) of the Luquillo Experimental Forest (LEF) in Puerto Rico. Stem density, tree height, and total above ground biomass varied by site. Significant differences in...

People & Tropical Rain Forests.

ERIC Educational Resources Information Center

NatureScope, 1989

1989-01-01

Discusses ways people who live in rain forests make a living and some of the products that enrich our lives. Provides activities covering forest people, tropical treats, jungle in the pantry, treetop explorers, and three copyable pages to accompany activities. (Author/RT)

Rain Forest Murals

ERIC Educational Resources Information Center

Kleiner, Cheryl

2010-01-01

The rain forest murals in the author's school began as a request from her principal to have students decorate the cafeteria with their own paintings. She decided to brainstorm ideas with her eighth-grade students. Taking into consideration the architectural space and the environmental concerns they wanted to convey, students chose the rain forest…

Arbuscular-Mycorrhizal Networks Inhibit Eucalyptus tetrodonta Seedlings in Rain Forest Soil Microcosms

PubMed Central

Janos, David P.; Scott, John; Aristizábal, Catalina; Bowman, David M. J. S.

2013-01-01

Eucalyptus tetrodonta, a co-dominant tree species of tropical, northern Australian savannas, does not invade adjacent monsoon rain forest unless the forest is burnt intensely. Such facilitation by fire of seedling establishment is known as the "ashbed effect." Because the ashbed effect might involve disruption of common mycorrhizal networks, we hypothesized that in the absence of fire, intact rain forest arbuscular mycorrhizal (AM) networks inhibit E. tetrodonta seedlings. Although arbuscular mycorrhizas predominate in the rain forest, common tree species of the northern Australian savannas (including adult E. tetrodonta) host ectomycorrhizas. To test our hypothesis, we grew E. tetrodonta and Ceiba pentandra (an AM-responsive species used to confirm treatments) separately in microcosms of ambient or methyl-bromide fumigated rain forest soil with or without severing potential mycorrhizal fungus connections to an AM nurse plant, Litsea glutinosa. As expected, C. pentandra formed mycorrhizas in all treatments but had the most root colonization and grew fastest in ambient soil. E. tetrodonta seedlings also formed AM in all treatments, but severing hyphae in fumigated soil produced the least colonization and the best growth. Three of ten E. tetrodonta seedlings in ambient soil with intact network hyphae died. Because foliar chlorosis was symptomatic of iron deficiency, after 130 days we began to fertilize half the E. tetrodonta seedlings in ambient soil with an iron solution. Iron fertilization completely remedied chlorosis and stimulated leaf growth. Our microcosm results suggest that in intact rain forest, common AM networks mediate belowground competition and AM fungi may exacerbate iron deficiency, thereby enhancing resistance to E. tetrodonta invasion. Common AM networks–previously unrecognized as contributors to the ashbed effect–probably help to maintain the rain forest–savanna boundary. PMID:23460899

Reliability of the Forest Service type rain gage

Treesearch

G. L. Hayes

1942-01-01

The Forest Service type rain-gage was originated by W. B. Osborne of the Portland, Oreg., office of the U. S. Forest Service to meet a need for reliable rainfall measurements at low cost. Many hundreds of them, over 700 on the national forests of northern Idaho and western Montana alone, are now being used during the summer months as aids to forest-fire control...

77 FR 47814 - Florida National Forests Resource Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-10

... CONTACT: Denise Rains, Public Affairs Officer, National Forests in Florida, 850-523-8568, email [email protected] agenda. Written comments and requests for time for oral comments must be sent to Denise Rains, U.S... , or via facsimile to 850-523-8505, Attention: Denise Rains. A summary of the meeting will be posted at...

Variability within the 10-Year Pollen Rain of a Seasonal Neotropical Forest and Its Implications for Paleoenvironmental and Phenological Research

PubMed Central

Haselhorst, Derek S.; Moreno, J. Enrique; Punyasena, Surangi W.

2013-01-01

Tropical paleoecologists use a combination of mud-water interface and modern pollen rain samples (local samples of airborne pollen) to interpret compositional changes within fossil pollen records. Taxonomic similarities between the composition of modern assemblages and fossil samples are the basis of reconstructing paleoclimates and paleoenvironments. Surface sediment samples reflect a time-averaged accumulation of pollen spanning several years or more. Due to experimental constraints, modern pollen rain samples are generally collected over shorter timeframes (1–3 years) and are therefore less likely to capture the full range of natural variability in pollen rain composition and abundance. This potentially biases paleoenvironmental interpretations based on modern pollen rain transfer functions. To determine the degree to which short-term environmental change affects the composition of the aerial pollen flux of Neotropical forests, we sampled ten years of the seasonal pollen rain from Barro Colorado Island, Panama and compared it to climatic and environmental data over the same ten-year span. We establish that the pollen rain effectively captured the strong seasonality and stratification of pollen flow within the forest canopy and that individual taxa had variable sensitivity to seasonal and annual changes in environmental conditions, manifested as changes in pollen productivity. We conclude that modern pollen rain samples capture the reproductive response of moist tropical plants to short-term environmental change, but that consequently, pollen rain-based calibrations need to include longer sampling periods (≥7 years) to reflect the full range of natural variability in the pollen output of a forest and simulate the time-averaging present in sediment samples. Our results also demonstrate that over the long-term, pollen traps placed in the forest understory are representative samples of the pollen output of both canopy and understory vegetation. Aerial pollen traps, therefore, also represent an underutilized means of monitoring the pollen productivity and reproductive behavior of moist tropical forests. PMID:23320089

Variability within the 10-year pollen rain of a seasonal neotropical forest and its implications for paleoenvironmental and phenological research.

PubMed

Haselhorst, Derek S; Moreno, J Enrique; Punyasena, Surangi W

2013-01-01

Tropical paleoecologists use a combination of mud-water interface and modern pollen rain samples (local samples of airborne pollen) to interpret compositional changes within fossil pollen records. Taxonomic similarities between the composition of modern assemblages and fossil samples are the basis of reconstructing paleoclimates and paleoenvironments. Surface sediment samples reflect a time-averaged accumulation of pollen spanning several years or more. Due to experimental constraints, modern pollen rain samples are generally collected over shorter timeframes (1-3 years) and are therefore less likely to capture the full range of natural variability in pollen rain composition and abundance. This potentially biases paleoenvironmental interpretations based on modern pollen rain transfer functions. To determine the degree to which short-term environmental change affects the composition of the aerial pollen flux of Neotropical forests, we sampled ten years of the seasonal pollen rain from Barro Colorado Island, Panama and compared it to climatic and environmental data over the same ten-year span. We establish that the pollen rain effectively captured the strong seasonality and stratification of pollen flow within the forest canopy and that individual taxa had variable sensitivity to seasonal and annual changes in environmental conditions, manifested as changes in pollen productivity. We conclude that modern pollen rain samples capture the reproductive response of moist tropical plants to short-term environmental change, but that consequently, pollen rain-based calibrations need to include longer sampling periods (≥7 years) to reflect the full range of natural variability in the pollen output of a forest and simulate the time-averaging present in sediment samples. Our results also demonstrate that over the long-term, pollen traps placed in the forest understory are representative samples of the pollen output of both canopy and understory vegetation. Aerial pollen traps, therefore, also represent an underutilized means of monitoring the pollen productivity and reproductive behavior of moist tropical forests.

Soil-calcium depletion linked to acid rain and forest growth in the eastern United States

USGS Publications Warehouse

Lawrence, Gregory B.; Huntington, T.G.

1999-01-01

Since the discovery of acid rain in the 1970's, scientists have been concerned that deposition of acids could cause depletion of calcium in forest soils. Research in the 1980's showed that the amount of calcium in forest soils is controlled by several factors that are difficult to measure. Further research in the 1990's, including several studies by the U.S. Geological Survey, has shown that (1) calcium in forest soils has decreased at locations in the northeastern and southeastern U.S., and (2) acid rain and forest growth (uptake of calcium from the soil by roots) are both factors contributing to calcium depletion.

Pollen-based biome reconstructions for Latin America at 0, 6000 and 18 000 radiocarbon years

USGS Publications Warehouse

Marchant, R.; Harrison, S.P.; Hooghiemstra, H.; Markgraf, Vera; Van Boxel, J. H.; Ager, T.; Almeida, L.; Anderson, R.; Baied, C.; Behling, H.; Berrio, J.C.; Burbridge, R.; Bjorck, S.; Byrne, R.; Bush, M.B.; Cleef, A.M.; Duivenvoorden, J.F.; Flenley, J.R.; De Oliveira, P.; Van Geel, B.; Graf, K.J.; Gosling, W.D.; Harbele, S.; Van Der Hammen, T.; Hansen, B.C.S.; Horn, S.P.; Islebe, G.A.; Kuhry, P.; Ledru, M.

2009-01-01

The biomisation method is used to reconstruct Latin American vegetation at 6000±500 and 18 000±1000 radiocarbon years before present (14C yr BP) from pollen data. Tests using modern pollen data from 381 samples derived from 287 locations broadly reproduce potential natural vegetation. The strong temperature gradient associated with the Andes is recorded by a transition from high altitude cool grass/shrubland and cool mixed forest to mid-altitude cool temperate rain forest, to tropical dry, seasonal and rain forest at low altitudes. Reconstructed biomes from a number of sites do not match the potential vegetation due to local factors such as human impact, methodological artefacts and mechanisms of pollen representivity of the parent vegetation. At 6000±500 14C yr BP 255 samples are analysed from 127 sites. Differences between the modern and the 6000±500 14C yr BP reconstruction are comparatively small. Patterns of change relative to the modern reconstruction are mainly to biomes characteristic of drier climate in the north of the region with a slight more mesic shift in the south. Cool temperate rain forest remains dominant in western South America. In northwestern South America a number of sites record transitions from tropical seasonal forest to tropical dry forest and tropical rain forest to tropical seasonal forest. Sites in Central America also show a change in biome assignment to more mesic vegetation, indicative of greater plant available moisture, e.g. on the Yucat??n peninsula sites record warm evergreen forest, replacing tropical dry forest and warm mixed forest presently recorded. At 18 000±1000 14C yr BP 61 samples from 34 sites record vegetation that reflects a generally cool and dry environment. Cool grass/shrubland prevalent in southeast Brazil, Amazonian sites record tropical dry forest, warm temperate rain forest and tropical seasonal forest. Southernmost South America is dominated by cool grass/shrubland, a single site retains cool temperate rain forest indicating that forest was present at some locations at the LGM. Some sites in Central M??xico and lowland Colombia remain unchanged in their biome assignments, although the affinities that these sites have to different biomes do change between 18 000±1000 14C yr BP and present. The " unresponsive" nature of these sites results from their location and the impact of local edaphic influence.

Seed dispersal limitations shift over time in tropical forest restoration.

PubMed

Reid, J Leighton; Holl, Karen D; Zahawi, Rakan A

2015-06-01

Past studies have shown that tropical forest regeneration on degraded farmlands is initially limited by lack of seed dispersal, but few studies have tracked changes in abundance and composition of seed rain past the first few years after land abandonment. We measured seed rain for 12 months in 10 6-9-year-old restoration sites and five mature, reference forests in southern Costa Rica in order to learn (1) if seed rain limitation persists past the first few years of regeneration; (2) how restoration treatments influence seed community structure and composition; and (3) whether seed rain limitation is contingent on landscape context. Each restoration site contained three 0.25-ha treatment plots: (1) a naturally regenerating control, (2) tree islands, and (3) a mixed-species tree plantation. Sites spanned a deforestation gradient with 9-89% forest area within 500 m around the treatment plots. Contrary to previous studies, we found that tree seeds were abundant and ubiquitous across all treatment plots (585.1 ± 142.0 seeds · m(-2) · yr(-1) [mean ± SE]), indicating that lack of seed rain ceased to limit forest regeneration within the first decade of recovery. Pioneer trees and shrubs comprised the vast majority of seeds, but compositional differences between restoration sites and reference forests were driven by rarer, large-seeded species. Large, animal-dispersed tree seeds were more abundant in tree islands (4.6 ± 2.9 seeds · m(-2) · yr(-1)) and plantations (5.8 ± 3.0 seeds · m(-2) · yr(-1)) than control plots (0.2 ± 0.1 seeds · m(-2) · yr(-1)), contributing to greater tree species richness in actively restored plots. Planted tree species accounted for < 1% of seeds. We found little evidence for landscape forest cover effects on seed rain, consistent with previous studies. We conclude that seed rain limitation shifted from an initial, complete lack of tree seeds to a specific limitation on large-seeded, mature forest species over the first decade. Although total seed abundance was equal among restoration treatments, tree plantations and tree islands continued to diversify seed rain communities compared to naturally regenerating controls. Compositional differences between regenerating plots and mature forests suggest that large-seeded tree species are appropriate candidates for enrichment planting.

Changes in habitat use at rainforest edges through succession: A case study of understory birds in the Brazilian Amazon

Treesearch

Luke L. Powell; Gustavo Zurita; Jared D.  Wolfe; Erik I.  Johnson; Philip C  Stouffer

2015-01-01

Primary tropical rain forests are being rapidly perforated with new edges via roads, logging, and pastures, and vast areas of secondary forest accumulate following abandonment of agricultural lands. To determine how insectivorous Amazonian understory birds respond to edges between primary rain forest and three age classes of secondary forest, we radio-tracked two...

Model gives a 3-month warning of Amazonian forest fires

NASA Astrophysics Data System (ADS)

Schultz, Colin

2011-08-01

The widespread drought suffered by the Amazon rain forest in the summer of 2005 was heralded at the time as the drought of the century. Because of the dehydrated conditions, supplemented by slash and burn agricultural practices, the drought led to widespread forest fires throughout the western Amazon, a portion of the rain forest usually too lush to support spreading wildfires. Only 5 years later, the 2005 season was outdone by even more widespread drought, with fires decimating more than 3000 square kilometers of western Amazonian rain forest. Blame for the wildfires has been consistently laid on deforestation and agricultural practices, but a convincing climatological explanation exists as well. (Geophysical Research Letters, doi:10.1029/2011GL047392, 2011)

Analysis of normalized radar cross section (sigma-O) signature of Amazon rain forest using SEASAT scatterometer data

NASA Technical Reports Server (NTRS)

Bracalente, E. M.; Sweet, J. L.

1984-01-01

The normalized radar cross section (NRCS) signature of the Amazon rain forest was SEASAT scatterometer data. Statistics of the measured (NRCS) values were determined from multiple orbit passes for three local time periods. Plots of mean normalized radar cross section, dB against incidence angle as a function of beam and polarization show that less than 0.3 dB relative bias exists between all beams over a range of incidence angle from 30 deg to 53 deg. The backscattered measurements analyzed show the Amazon rain forest to be relatively homogeneous, azimuthally isotropic and insensitive to polarization. The return from the rain forest target appears relatively consistent and stable, except for the small diurnal variation (0.75 dB) that occurs at sunrise. Because of the relative stability of the rain forest target and the scatterometer instrument, the response of versus incidence angle was able to detect errors in the estimated yaw altitude angle. Also, small instrument gain biases in some of the processing channels were detected. This led to the development of an improved NRCS algorithm, which uses a more accurate method for estimating the system noise power.

Seed rain, soil seed bank, seed loss and regeneration of Castanopsis fargesii (Fagaceae) in a subtropical evergreen broad-leaved forest

Treesearch

Xiaojun Du; Qinfeng Guo; Xianming Gao; Keping Na

2007-01-01

Understanding the seed rain and seed loss dynamics in the natural condition has important significance for revealing the natural regeneration mechanisms.We conducted a 3-year field observation on seed rain, seed loss and natural regeneration of Castanopsis fargesii Franch., a dominant tree species in evergreen broad-leaved forests in Dujiangyan,...

Seed invasion filters and forest fire severity

Treesearch

Tom R. Cottrell; Paul F. Hessburg; Jonathan A. Betz

2008-01-01

Forest seed dispersal is altered after fire. Using seed traps, we studied impacts of fire severity on timing of seed dispersal, total seed rain, and seed rain richness in patches of high and low severity fire and unburned Douglas-fir (Pseudotsuga menziesii) forests in the Fischer and Tyee fire complexes in the eastern Washington Cascades. Unburned...

Response of soil respiration to acid rain in forests of different maturity in southern China.

PubMed

Liang, Guohua; Liu, Xingzhao; Chen, Xiaomei; Qiu, Qingyan; Zhang, Deqiang; Chu, Guowei; Liu, Juxiu; Liu, Shizhong; Zhou, Guoyi

2013-01-01

The response of soil respiration to acid rain in forests, especially in forests of different maturity, is poorly understood in southern China despite the fact that acid rain has become a serious environmental threat in this region in recent years. Here, we investigated this issue in three subtropical forests of different maturity [i.e. a young pine forest (PF), a transitional mixed conifer and broadleaf forest (MF) and an old-growth broadleaved forest (BF)] in southern China. Soil respiration was measured over two years under four simulated acid rain (SAR) treatments (CK, the local lake water, pH 4.5; T1, water pH 4.0; T2, water pH 3.5; and T3, water pH 3.0). Results indicated that SAR did not significantly affect soil respiration in the PF, whereas it significantly reduced soil respiration in the MF and the BF. The depressed effects on both forests occurred mostly in the warm-wet seasons and were correlated with a decrease in soil microbial activity and in fine root biomass caused by soil acidification under SAR. The sensitivity of the response of soil respiration to SAR showed an increasing trend with the progressive maturity of the three forests, which may result from their differences in acid buffering ability in soil and in litter layer. These results indicated that the depressed effect of acid rain on soil respiration in southern China may be more pronounced in the future in light of the projected change in forest maturity. However, due to the nature of this field study with chronosequence design and the related pseudoreplication for forest types, this inference should be read with caution. Further studies are needed to draw rigorous conclusions regarding the response differences among forests of different maturity using replicated forest types.

Response of Soil Respiration to Acid Rain in Forests of Different Maturity in Southern China

PubMed Central

Chen, Xiaomei; Qiu, Qingyan; Zhang, Deqiang; Chu, Guowei; Liu, Juxiu; Liu, Shizhong; Zhou, Guoyi

2013-01-01

The response of soil respiration to acid rain in forests, especially in forests of different maturity, is poorly understood in southern China despite the fact that acid rain has become a serious environmental threat in this region in recent years. Here, we investigated this issue in three subtropical forests of different maturity [i.e. a young pine forest (PF), a transitional mixed conifer and broadleaf forest (MF) and an old-growth broadleaved forest (BF)] in southern China. Soil respiration was measured over two years under four simulated acid rain (SAR) treatments (CK, the local lake water, pH 4.5; T1, water pH 4.0; T2, water pH 3.5; and T3, water pH 3.0). Results indicated that SAR did not significantly affect soil respiration in the PF, whereas it significantly reduced soil respiration in the MF and the BF. The depressed effects on both forests occurred mostly in the warm-wet seasons and were correlated with a decrease in soil microbial activity and in fine root biomass caused by soil acidification under SAR. The sensitivity of the response of soil respiration to SAR showed an increasing trend with the progressive maturity of the three forests, which may result from their differences in acid buffering ability in soil and in litter layer. These results indicated that the depressed effect of acid rain on soil respiration in southern China may be more pronounced in the future in light of the projected change in forest maturity. However, due to the nature of this field study with chronosequence design and the related pseudoreplication for forest types, this inference should be read with caution. Further studies are needed to draw rigorous conclusions regarding the response differences among forests of different maturity using replicated forest types. PMID:23626790

The Role of Fog in Ecosystem Hydrology: Initial Results from Investigations Using Stable Isotopes of Water in Hawaiian Cloud Forests

NASA Astrophysics Data System (ADS)

Scholl, M. A.; Gingerich, S. B.; Giambelluca, T. W.; Nullet, M. A.; Loope, L. L.

2002-05-01

The role of fog drip in cloud forest ecosystems is being investigated at two sites, one each on the windward and leeward sides of East Maui, Hawaii. The study involves using the different isotopic signatures of fog (cloud water) and rain to trace fog through the forest water cycle, as well as comparing relative amounts of fog, rain, and throughfall. At each site, volume of rain, fog plus rain, and throughfall is recorded hourly. Stable isotope samples of rain, fog, soil water, stream water, and tree sap are collected monthly, and each site has a visibility sensor and weather station. The windward site, at 1950 m altitude, is enveloped by orographic clouds under trade wind conditions almost every day. This site is near the upper boundary of extensive forested mountain slopes that are a major watershed for the island. Volume data suggest that fog drip (compared to rain as measured by a standard gage) contributes substantially to the forest water budget on the windward side. Tree sap deuterium composition was consistently similar to fog composition for samples analyzed thus far, while soil water was isotopically lighter, possibly reflecting a mixture of fog with rain or shallow groundwater. The leeward site, at 1220 m, is often in a cloud bank under trade wind conditions. During the summer the major source of precipitation is cloud water; rainfall generally occurs during winter storms. Scattered cloud forest remnants persist at this site despite degradation of extensive native forest by ungulate browsing, plant invasion, and fire. Here, fog drip was a smaller proportion of the total precipitation than at the windward site, but exceeded rainfall for some precipitation events. Unlike the windward site, tree sap and soil water had similar isotopic composition. The information gained from this study underscores the importance of trees and shrubs in extracting cloud water that contributes to soil moisture, groundwater recharge, and stream flow in watersheds.

Pollen-based biome reconstructions for Latin America at 0, 6000 and 18 000 radiocarbon years ago

USGS Publications Warehouse

Marchant, R.; Cleef, A.; Harrison, S.P.; Hooghiemstra, H.; Markgraf, Vera; Van Boxel, J.; Ager, T.; Almeida, L.; Anderson, R.; Baied, C.; Behling, H.; Berrio, J.C.; Burbridge, R.; Bjorck, S.; Byrne, R.; Bush, M.; Duivenvoorden, J.; Flenley, J.; De Oliveira, P.; Van Gee, B.; Graf, K.; Gosling, W.D.; Harbele, S.; Van Der Hammen, T.; Hansen, B.; Horn, S.; Kuhry, P.; Ledru, M.-P.; Mayle, F.; Leyden, B.; Lozano-Garcia, S.; Melief, A.M.; Moreno, P.; Moar, N.T.; Prieto, A.; Van Reenen, G.; Salgado-Labouriau, M.; Schabitz, F.; Schreve-Brinkman, E. J.; Wille, M.

2009-01-01

The biomisation method is used to reconstruct Latin American vegetation at 6000??500 and 18 000??1000 radiocarbon years before present ( 14C yr BP) from pollen data. Tests using modern pollen data from 381 samples derived from 287 locations broadly reproduce potential natural vegetation. The strong temperature gradient associated with the Andes is recorded by a transition from high altitude cool grass/shrubland and cool mixed forest to mid-altitude cool temperate rain forest, to tropical dry, seasonal and rain forest at low altitudes. Reconstructed biomes from a number of sites do not match the potential vegetation due to local factors such as human impact, methodological artefacts and mechanisms of pollen representivity of the parent vegetation. At 6000??500 14C yr BP 255 samples are analysed from 127 sites. Differences between the modern and the 6000??500 14C yr BP reconstruction are comparatively small; change relative to the modern reconstruction are mainly to biomes characteristic of drier climate in the north of the region with a slight more mesic shift in the south. Cool temperate rain forest remains dominant in western South America. In northwestern South America a number of sites record transitions from tropical seasonal forest to tropical dry forest and tropical rain forest to tropical seasonal forest. Sites in Central America show a change in biome assignment, but to more mesic vegetation, indicative of greater plant available moisture, e.g. on the Yucat??n peninsula sites record warm evergreen forest, replacing tropical dry forest and warm mixed forest presently recorded. At 18 000??1000 14C yr BP 61 samples from 34 sites record vegetation reflecting a generally cool and dry environment. Cool grass/shrubland is prevalent in southeast Brazil whereas Amazonian sites record tropical dry forest, warm temperate rain forest and tropical seasonal forest. Southernmost South America is dominated by cool grass/shrubland, a single site retains cool temperate rain forest indicating that forest was present at some locations at the LGM. Some sites in Central Mexico and lowland Colombia remain unchanged in the biome assignments of warm mixed forest and tropical dry forest respectively, although the affinities that these sites have to different biomes do change between 18000??1000 14C yr BP and present. The "unresponsive" nature of these sites results from their location and the impact of local edaphic influence. ?? Author(s) 2009.

Acid rain impacts on calcium nutrition and forest health

Treesearch

Donald H. DeHayes; Paul G. Schaberg; Gary J. Hawley; G. Richard Strimbeck

1999-01-01

Forest ecosystems throughout the world are exposed to acid rain, a complex solution consisting largely of H+, SO42-, NH4+, and NO3- pollutant ions derived from sulfur and nitrogen oxides. Although the public in...

EFFECT OF SIMULATED SULFURIC ACID RAIN ON THE CHEMISTRY OF A SULFATE-ADSORBING FOREST SOIL

EPA Science Inventory

Simulated H2SO4 rain (pH 3.0, 3.5, 4.0) or control rain (pH 5.6) was applied for 3.5 yr to large lysimeter boxes containing a sulfate-adsorbing forest soil and either red alder (Alnus rubra) or sugar maple (Acer saccharum) seedlings. After removal of the plants and the litter lay...

Understanding the role of fog in forest hydrology: Stable isotopes as tools for determining input and partitioning of cloud water in montane forests

USGS Publications Warehouse

Scholl, M.; Eugster, W.; Burkard, R.

2011-01-01

Understanding the hydrology of tropical montane cloud forests (TMCF) has become essential as deforestation of mountain areas proceeds at an increased rate worldwide. Passive and active cloud-water collectors, throughfall and stemflow collectors, visibility or droplet size measurements, and micrometeorological sensors are typically used to measure the fog water inputs to ecosystems. In addition, stable isotopes may be used as a natural tracer for fog and rain. Previous studies have shown that the isotopic signature of fog tends to be more enriched in the heavier isotopes 2H and 18O than that of rain, due to differences in condensation temperature and history. Differences between fog and rain isotopes are largest when rain is from synoptic-scale storms, and fog or orographic cloud water is generated locally. Smaller isotopic differences have been observed between rain and fog on mountains with orographic clouds, but only a few studies have been conducted. Quantifying fog deposition using isotope methods is more difficult in forests receiving mixed precipitation, because of limitations in the ability of sampling equipment to separate fog from rain, and because fog and rain may, under some conditions, have similar isotopic composition. This article describes the various types of fog most relevant to montane cloud forests and the importance of fog water deposition in the hydrologic budget. A brief overview of isotope hydrology provides the background needed to understand isotope applications in cloud forests. A summary of previous work explains isotopic differences between rain and fog in different environments, and how monitoring the isotopic signature of surface water, soil water and tree xylem water can yield estimates of the contribution of fog water to streamflow, groundwater recharge and transpiration. Next, instrumentation to measure fog and rain, and methods to determine isotopic concentrations in plant and soil water are discussed. The article concludes with the identification of some of the more pressing research questions in this field and offers various suggestions for future research. ?? 2010 This article is a US Government work and is in the public domain in the USA.

Tangled trends for temperate rain forests as temperatures tick up

Treesearch

Noreen Parks; Tara Barrett

2013-01-01

Climate change is altering growing conditions in the temperate rain forest region that extends from northern California to the Gulf of Alaska. Longer, warmer growing seasons are generally increasing the overall potential for forest growth in the region. However, species differ in their ability to adapt to changing conditions. For example, researchers with Pacific...

How effective are DNA barcodes in the identification of African rainforest trees?

PubMed

Parmentier, Ingrid; Duminil, Jérôme; Kuzmina, Maria; Philippe, Morgane; Thomas, Duncan W; Kenfack, David; Chuyong, George B; Cruaud, Corinne; Hardy, Olivier J

2013-01-01

DNA barcoding of rain forest trees could potentially help biologists identify species and discover new ones. However, DNA barcodes cannot always distinguish between closely related species, and the size and completeness of barcode databases are key parameters for their successful application. We test the ability of rbcL, matK and trnH-psbA plastid DNA markers to identify rain forest trees at two sites in Atlantic central Africa under the assumption that a database is exhaustive in terms of species content, but not necessarily in terms of haplotype diversity within species. We assess the accuracy of identification to species or genus using a genetic distance matrix between samples either based on a global multiple sequence alignment (GD) or on a basic local alignment search tool (BLAST). Where a local database is available (within a 50 ha plot), barcoding was generally reliable for genus identification (95-100% success), but less for species identification (71-88%). Using a single marker, best results for species identification were obtained with trnH-psbA. There was a significant decrease of barcoding success in species-rich clades. When the local database was used to identify the genus of trees from another region and did include all genera from the query individuals but not all species, genus identification success decreased to 84-90%. The GD method performed best but a global multiple sequence alignment is not applicable on trnH-psbA. Barcoding is a useful tool to assign unidentified African rain forest trees to a genus, but identification to a species is less reliable, especially in species-rich clades, even using an exhaustive local database. Combining two markers improves the accuracy of species identification but it would only marginally improve genus identification. Finally, we highlight some limitations of the BLAST algorithm as currently implemented and suggest possible improvements for barcoding applications.

How Effective Are DNA Barcodes in the Identification of African Rainforest Trees?

PubMed Central

Parmentier, Ingrid; Duminil, Jérôme; Kuzmina, Maria; Philippe, Morgane; Thomas, Duncan W.; Kenfack, David; Chuyong, George B.; Cruaud, Corinne; Hardy, Olivier J.

2013-01-01

Background DNA barcoding of rain forest trees could potentially help biologists identify species and discover new ones. However, DNA barcodes cannot always distinguish between closely related species, and the size and completeness of barcode databases are key parameters for their successful application. We test the ability of rbcL, matK and trnH-psbA plastid DNA markers to identify rain forest trees at two sites in Atlantic central Africa under the assumption that a database is exhaustive in terms of species content, but not necessarily in terms of haplotype diversity within species. Methodology/Principal Findings We assess the accuracy of identification to species or genus using a genetic distance matrix between samples either based on a global multiple sequence alignment (GD) or on a basic local alignment search tool (BLAST). Where a local database is available (within a 50 ha plot), barcoding was generally reliable for genus identification (95–100% success), but less for species identification (71–88%). Using a single marker, best results for species identification were obtained with trnH-psbA. There was a significant decrease of barcoding success in species-rich clades. When the local database was used to identify the genus of trees from another region and did include all genera from the query individuals but not all species, genus identification success decreased to 84–90%. The GD method performed best but a global multiple sequence alignment is not applicable on trnH-psbA. Conclusions/Significance Barcoding is a useful tool to assign unidentified African rain forest trees to a genus, but identification to a species is less reliable, especially in species-rich clades, even using an exhaustive local database. Combining two markers improves the accuracy of species identification but it would only marginally improve genus identification. Finally, we highlight some limitations of the BLAST algorithm as currently implemented and suggest possible improvements for barcoding applications. PMID:23565134

Differences in seed rain composition in small and large fragments in the northeast Brazilian Atlantic Forest.

PubMed

Knörr, U C; Gottsberger, G

2012-09-01

Tropical forests are seriously threatened by fragmentation and habitat loss. The impact of fragment size and forest configuration on the composition of seed rain is insufficiently studied. For the present study, seed rain composition of small and large forest fragments (8-388 ha) was assessed in order to identify variations in seed abundance, species richness, seed size and dispersal mode. Seed rain was documented during a 1-year period in three large and four small Atlantic Forest fragments that are isolated by a sugarcane matrix. Total seed rain included 20,518 seeds of 149 species of trees, shrubs, palms, lianas and herbs. Most species and seeds were animal-dispersed. A significant difference in the proportion of seeds and species within different categories of seed size was found between small and large fragments. Small fragments received significantly more very small-sized seeds (<0.3 cm) and less large-seeded species (>1.5 cm) that were generally very rare, with only one species in small and eight in large fragments. We found a negative correlation between the inflow of small-sized seeds and the percentage of forest cover. Species richness was lower in small than in large fragments, but the difference was not very pronounced. Given our results, we propose changing plant species pools through logging, tree mortality and a high inflow of pioneer species and lianas, especially in small forest fragments and areas with low forest cover. Connecting forest fragments through corridors and reforestation with local large-seeded tree species may facilitate the maintenance of species diversity. © 2012 German Botanical Society and The Royal Botanical Society of the Netherlands.

Pollen-based biome reconstructions for Latin America at 0, 6000 and 18 000 radiocarbon years

USGS Publications Warehouse

Marchant, R.; Harrison, S.P.; Hooghiemstra, H.; Markgraf, Vera; Van Boxel, J. H.; Ager, T.; Almeida, L.; Anderson, R.; Baied, C.; Behling, H.; Berrio, J.C.; Burbridge, R.; Bjorck, S.; Byrne, R.; Bush, M.B.; Cleef, A.M.; Duivenvoorden, J.F.; Flenley, J.R.; De Oliveira, P.; Van Geel, B.; Graf, K.J.; Gosling, W.D.; Harbele, S.; Van Der Hammen, T.; Hansen, B.C.S.; Horn, S.P.; Islebe, G.A.; Kuhry, P.; Ledru, M.-P.; Mayle, F.E.; Leyden, B.W.; Lozano-Garcia, S.; Melief, A.B.M.; Moreno, P.; Moar, N.T.; Prieto, A.; Van Reenen, G. B.; Salgado-Labouriau, M. L.; Schasignbitz, F.; Schreve-Brinkman, E. J.; Wille, M.

2009-01-01

The biomisation method is used to reconstruct Latin American vegetation at 6000±500 and 18 000±1000 radiocarbon years before present (14C yr BP) from pollen data. Tests using modern pollen data from 381 samples derived from 287 locations broadly reproduce potential natural vegetation. The strong temperature gradient associated with the Andes is recorded by a transition from high altitude cool grass/shrubland and cool mixed forest to mid-altitude cool temperate rain forest, to tropical dry, seasonal and rain forest at low altitudes. Reconstructed biomes from a number of sites do not match the potential vegetation due to local factors such as human impact, methodological artefacts and mechanisms of pollen representivity of the parent vegetation.

At 6000±500 14C yr BP 255 samples are analysed from 127 sites. Differences between the modern and the 6000±500 14C yr BP reconstruction are comparatively small. Patterns of change relative to the modern reconstruction are mainly to biomes characteristic of drier climate in the north of the region with a slight more mesic shift in the south. Cool temperate rain forest remains dominant in western South America. In northwestern South America a number of sites record transitions from tropical seasonal forest to tropical dry forest and tropical rain forest to tropical seasonal forest. Sites in Central America also show a change in biome assignment to more mesic vegetation, indicative of greater plant available moisture, e.g. on the Yucat??n peninsula sites record warm evergreen forest, replacing tropical dry forest and warm mixed forest presently recorded.

At 18 000±1000 14C yr BP 61 samples from 34 sites record vegetation that reflects a generally cool and dry environment. Cool grass/shrubland prevalent in southeast Brazil, Amazonian sites record tropical dry forest, warm temperate rain forest and tropical seasonal forest. Southernmost South America is dominated by cool grass/shrubland, a single site retains cool temperate rain forest indicating that forest was present at some locations at the LGM. Some sites in Central M??xico and lowland Colombia remain unchanged in their biome assignments, although the affinities that these sites have to different biomes do change between 18 000±1000 14C yr BP and present. The " unresponsive" nature of these sites results from their location and the impact of local edaphic influence.

Growth and yield model application in tropical rain forest management

Treesearch

James Atta-Boateng; John W., Jr. Moser

2000-01-01

Analytical tools are needed to evaluate the impact of management policies on the sustainable use of rain forest. Optimal decisions concerning the level of management inputs require accurate predictions of output at all relevant input levels. Using growth data from 40 l-hectare permanent plots obtained from the semi-deciduous forest of Ghana, a system of 77 differential...

Foliar and ecosystem respiration in an old-growth tropical rain forest

Treesearch

Molly A. Cavaleri; Steven F. Oberbauer; Michael G. Ryan

2008-01-01

Foliar respiration is a major component of ecosystem respiration, yet extrapolations are often uncertain in tropical forests because of indirect estimates of leaf area index (LAI).A portable tower was used to directly measure LAI and night-time foliar respiration from 52 vertical transects throughout an old-growth tropical rain forest in Costa Rica. In this study, we (...

Threshold responses to soil moisture deficit by trees and soil in tropical rain forests: insights from field experiments

Treesearch

Patrick Meir; Tana Wood; David R. Galbraith; Paulo M. Brando; Antonio C.I. Da Costa; Lucy Rowland; Leandro V. Ferreira

2015-01-01

Many tropical rain forest regions are at risk of increased future drought. The net effects of drought on forest ecosystem functioning will be substantial if important ecological thresholds are passed. However, understanding and predicting these effects is challenging using observational studies alone. Field-based rainfall exclusion (canopy throughfall exclusion; TFE)...

Calculation of Individual Tree Water Use in a Bornean Tropical Rain Forest Using Individual-Based Dynamic Vegetation Model SEIB-DGVM

NASA Astrophysics Data System (ADS)

Nakai, T.; Kumagai, T.; Saito, T.; Matsumoto, K.; Kume, T.; Nakagawa, M.; Sato, H.

2015-12-01

Bornean tropical rain forests are among the moistest biomes of the world with abundant rainfall throughout the year, and considered to be vulnerable to a change in the rainfall regime; e.g., high tree mortality was reported in such forests induced by a severe drought associated with the ENSO event in 1997-1998. In order to assess the effect (risk) of future climate change on eco-hydrology in such tropical rain forests, it is important to understand the water use of trees individually, because the vulnerability or mortality of trees against climate change can depend on the size of trees. Therefore, we refined the Spatially Explicit Individual-Based Dynamic Global Vegetation Model (SEIB-DGVM) so that the transpiration and its control by stomata are calculated for each individual tree. By using this model, we simulated the transpiration of each tree and its DBH-size dependency, and successfully reproduced the measured data of sap flow of trees and eddy covariance flux data obtained in a Bornean lowland tropical rain forest in Lambir Hills National Park, Sarawak, Malaysia.

First direct landscape-scale measurement of tropical rain forest Leaf Area Index, a key driver of global primary productivity

Treesearch

David B. Clark; Paulo C. Olivas; Steven F. Oberbauer; Deborah A. Clark; Michael G. Ryan

2008-01-01

Leaf Area Index (leaf area per unit ground area, LAI) is a key driver of forest productivity but has never previously been measured directly at the landscape scale in tropical rain forest (TRF). We used a modular tower and stratified random sampling to harvest all foliage from forest floor to canopy top in 55 vertical transects (4.6 m2) across 500 ha of old growth in...

Seasonal rhythms of seed rain and seedling emergence in two tropical rain forests in southern Brazil.

PubMed

Marques, M C M; Oliveira, P E A M

2008-09-01

Seasonal tropical forests show rhythms in reproductive activities due to water stress during dry seasons. If both seed dispersal and seed germination occur in the best environmental conditions, mortality will be minimised and forest regeneration will occur. To evaluate whether non-seasonal forests also show rhythms, for 2 years we studied the seed rain and seedling emergence in two sandy coastal forests (flooded and unflooded) in southern Brazil. In each forest, one 100 x 30-m grid was marked and inside it 30 stations comprising two seed traps (0.5 x 0.5 m each) and one plot (2 x 2 m) were established for monthly monitoring of seed rain and a seedling emergence study, respectively. Despite differences in soil moisture and incident light on the understorey, flooded and unflooded forests had similar dispersal and germination patterns. Seed rain was seasonal and bimodal (peaks at the end of the wetter season and in the less wet season) and seedling emergence was seasonal and unimodal (peaking in the wetter season). Approximately 57% of the total species number had seedling emergence 4 or more months after dispersal. Therefore, both seed dormancy and the timing of seed dispersal drive the rhythm of seedling emergence in these forests. The peak in germination occurs in the wetter season, when soil fertility is higher and other phenological events also occur. The strong seasonality in these plant communities, even in this weakly seasonal climate, suggests that factors such as daylength, plant sensitivity to small changes in the environment (e.g. water and nutrient availability) or phylogenetic constraints cause seasonal rhythms in the plants.

Holocene History of the Chocó Rain Forest from Laguna Piusbi, Southern Pacific Lowlands of Colombia

NASA Astrophysics Data System (ADS)

Behling, Hermann; Hooghiemstra, Henry; Negret, Alvaro José

1998-11-01

A high-resolution pollen record from a 5-m-long sediment core from the closed-lake basin Laguna Piusbi in the southern Colombian Pacific lowlands of Chocó, dated by 11 AMS 14C dates that range from ca. 7670 to 220 14C yr B.P., represents the first Holocene record from the Chocó rain forest area. The interval between 7600 and 6100 14C yr B.P. (500-265 cm), composed of sandy clays that accumulated during the initial phase of lake formation, is almost barren of pollen. Fungal spores and the presence of herbs and disturbance taxa suggest the basin was at least temporarily inundated and the vegetation was open. The closed lake basin might have formed during an earthquake, probably about 4400 14C yr B.P. From the interval of about 6000 14C yr B.P. onwards, 200 different pollen and spore types were identified in the core, illustrating a diverse floristic composition of the local rain forest. Main taxa are Moraceae/Urticaceae, Cecropia,Melastomataceae/Combretaceae, Acalypha, Alchornea,Fabaceae, Mimosa, Piper, Protium, Sloanea, Euterpe/Geonoma, Socratea,and Wettinia.Little change took place during that time interval. Compared to the pollen records from the rain forests of the Colombian Amazon basin and adjacent savannas, the Chocó rain forest ecosystem has been very stable during the late Holocene. Paleoindians probably lived there at least since 3460 14C yr B.P. Evidence of agricultural activity, shown by cultivation of Zea maissurrounding the lake, spans the last 1710 yr. Past and present very moist climate and little human influence are important factors in maintaining the stable ecosystem and high biodiversity of the Chocó rain forest.

Threshold Responses to Soil Moisture Deficit by Trees and Soil in Tropical Rain Forests: Insights from Field Experiments

PubMed Central

Meir, Patrick; Wood, Tana E.; Galbraith, David R.; Brando, Paulo M.; Da Costa, Antonio C. L.; Rowland, Lucy; Ferreira, Leandro V.

2015-01-01

Many tropical rain forest regions are at risk of increased future drought. The net effects of drought on forest ecosystem functioning will be substantial if important ecological thresholds are passed. However, understanding and predicting these effects is challenging using observational studies alone. Field-based rainfall exclusion (canopy throughfall exclusion; TFE) experiments can offer mechanistic insight into the response to extended or severe drought and can be used to help improve model-based simulations, which are currently inadequate. Only eight TFE experiments have been reported for tropical rain forests. We examine them, synthesizing key results and focusing on two processes that have shown threshold behavior in response to drought: (1) tree mortality and (2) the efflux of carbon dioxdie from soil, soil respiration. We show that: (a) where tested using large-scale field experiments, tropical rain forest tree mortality is resistant to long-term soil moisture deficit up to a threshold of 50% of the water that is extractable by vegetation from the soil, but high mortality occurs beyond this value, with evidence from one site of increased autotrophic respiration, and (b) soil respiration reaches its peak value in response to soil moisture at significantly higher soil moisture content for clay-rich soils than for clay-poor soils. This first synthesis of tropical TFE experiments offers the hypothesis that low soil moisture–related thresholds for key stress responses in soil and vegetation may prove to be widely applicable across tropical rain forests despite the diversity of these forests. PMID:26955085

Palaeohydrological and palaeoecological studies on South Cameroonian alluvial sedimentary basins - New evidence on the palaeoenvironmental evolution of western Central Africa since the Late Pleistocene

NASA Astrophysics Data System (ADS)

Sangen, M.

2009-04-01

A new valuable and innovative contribution will be presented to ascertain the timing and extension of climatic and ecological changes in western equatorial Africa. Main focus is laid on the dynamics of climate, fluvial systems and the high sensitive tropical ecosystems (dense evergreen and semi-deciduous rain forest and savanna-rain forest margin) since the Late Pleistocene (~50 kyrs. BP). For this purpose extended fieldworks were carried out in South Cameroon (2004-2008) by the ReSaKo-Project (sub-project of DFG-Project 510) with abundant investigations on alluvial sedimentary basins of equatorial tropical fluvial systems. Suitable alluvial sediment-archives for palaeoenvironmental research were uncovered along selected braiding, meandering and anabranching/anastomosing reaches of major southwestern, into the Gulf of Guinea (Ntem, Nyong and Sanaga) and southeastern, into the Congo basin (Boumba, Dja and Ngoko) draining rivers (RUNGE et al. 2006, SANGEN 2008). Among geomorphological investigations and cross section discussions, 150 corings (Edelman, 20 cm layers) reaching maximum depths of 550 cm were carried out on river benches, levees, cut-off and periodical branches, islands and terraces as well as in seasonal inundated floodplains and backswamps. Corresponding sedimentary profiles and catenae recovered multilayered, sandy to clayey alluvia containing sedimentary form-units and palaeosurfaces which contribute to the reconstruction of palaeoenvironmental conditions in western equatorial Africa. Several (59) radiocarbon (AMS) dated samples (Erlangen and Lecce) from fossil organic layers and macro-rests embedded in these units yielded Late Pleistocene to recent ages (14C-ages around 48 to 0.2 kyrs. BP), spanning also the Last Glacial Maximum (LGM) and Holocene record. Abrupt grain-size modifications and alternating form-units (sandy and clayey layers, palaeosurfaces) in the stratigraphic records display fluctuations in the fluvial-morphological response of the fluvial systems to climatic variability and other extrinsic and intrinsic impacts. Although the sedimentary record varies among the studied river reaches, fossil organic sediment layers (palaeosurfaces) containing valuable proxy data were found in almost all alluvia basins of examined southern Cameroonian rivers. Around 56 ^13C-values corresponding to the dated samples (-31.4 to -18.0 ) evidence that despite major disturbances of the African rain forest over geological times (MALEY 2001) mainly rain forest ecosystems have prevailed during the corresponding time periods, presumably as gallery forests, which were able to persist in this fluvial habitat ("fluvial refuge"), even during arid periods (e.g. LGM). The results are consistent with earlier findings from lacustrine (SERVANT & SERVANT-VILDARY 2000), marine (WELDEAB et al. 2007) and additional sediment archives (GASSE et al. 2008) and will add additional insights and information to the unravelling of the complex respond of the African monsoon, the Central African ecosystems and fluvial systems to Late Quaternary climatic and environmental fluctuations within a globally teleconnected system. References: GASSE, F., CHALIé, F., VINCENS, A., WILLIAMS, M.A.J. & WILLIAMSON, D. (2008): Climatic patterns in equatorial and southern Africa from 30,000 to 10,000 years ago reconstructed from terrestrial and near-shore proxy data. Quaternary Science Reviews, 27 (25-26), 2316-2340. MALEY, J. (2001): The impact of arid phases on the African rain forest through geological history. In: WEBER, W., WHITE, L., VEDDER, A., NAUGHTON-TREVES, L. (Eds.): African rain forest ecology and conservation - An interdisciplinary perspective. Yale University Press, New Haven, 68-87. RUNGE, J., EISENBERG, J., SANGEN, M. (2006): Geomorphic evolution of the Ntem alluvial basin and physiogeographic evidence for Holocene environmental changes in the rain forest of SW Cameroon (Central Africa) - preliminary results. Z. Geomorph. N.F., Suppl. Bd. 145, 63-79. SERVANT, M. & SERVANT-VILDARY, S. (2000): Dynamique à long terme des écosystèmes forestiers intertropicaux. Publications issues du Symposium international « Dynamique à long terme des écosystèmes forestiers intertropicaux », Paris, 20-22 mars 1996. Paris, UNESCO, 1-434. WELDEAB, S., LEA, D.W., SCHNEIDER, R.R. & ANDERSEN, N. (2007): 155,000 years of West African monsoon ocean thermal evolution. Science, 316, 1303-1307.

Natural Experiment Demonstrates That Bird Loss Leads to Cessation of Dispersal of Native Seeds from Intact to Degraded Forests

PubMed Central

HilleRisLambers, Janneke; Tewksbury, Joshua J.; Rogers, Haldre S.

2013-01-01

In healthy forests, vertebrate frugivores move seeds from intact to degraded forests, aiding in the passive regeneration of degraded forests. Yet vertebrate frugivores are declining around the world, and little is known about the impact of this loss on regeneration of degraded areas. Here, we use a unique natural experiment to assess how complete vertebrate frugivore loss affects native seed rain in degraded forest. All native vertebrate frugivores (which were primarily avian frugivores) have been functionally extirpated from the island of Guam by the invasive brown tree snake (Boiga irregularis), whereas the nearby island of Saipan has a relatively intact vertebrate frugivore community. We captured seed rain along transects extending from intact into degraded forest and compared the species richness, density and condition of the seed rain from native bird-dispersed tree species between the two islands. Considering seeds from native bird-dispersed species, approximately 1.66 seeds landed per 26 days in each square meter of degraded forest on Saipan, whereas zero seeds landed per 26 days per square meter in degraded forest on Guam. Additionally, on Saipan, 69% of native bird-dispersed seeds in intact forest and 77% of seeds in degraded forest lacked fleshy fruit pulp, suggesting ingestion by birds, compared to 0% of all seeds on Guam. Our results show an absence of seed rain in degraded forests on Guam, correlated with the absence of birds, whereas on Saipan, frugivorous birds regularly disperse seeds into degraded forests, providing a mechanism for re-colonization by native plants. These results suggest that loss of frugivores will slow regeneration of degraded forests on Guam. PMID:23741503

Natural experiment demonstrates that bird loss leads to cessation of dispersal of native seeds from intact to degraded forests.

PubMed

Caves, Eleanor M; Jennings, Summer B; Hillerislambers, Janneke; Tewksbury, Joshua J; Rogers, Haldre S

2013-01-01

In healthy forests, vertebrate frugivores move seeds from intact to degraded forests, aiding in the passive regeneration of degraded forests. Yet vertebrate frugivores are declining around the world, and little is known about the impact of this loss on regeneration of degraded areas. Here, we use a unique natural experiment to assess how complete vertebrate frugivore loss affects native seed rain in degraded forest. All native vertebrate frugivores (which were primarily avian frugivores) have been functionally extirpated from the island of Guam by the invasive brown tree snake (Boiga irregularis), whereas the nearby island of Saipan has a relatively intact vertebrate frugivore community. We captured seed rain along transects extending from intact into degraded forest and compared the species richness, density and condition of the seed rain from native bird-dispersed tree species between the two islands. Considering seeds from native bird-dispersed species, approximately 1.66 seeds landed per 26 days in each square meter of degraded forest on Saipan, whereas zero seeds landed per 26 days per square meter in degraded forest on Guam. Additionally, on Saipan, 69% of native bird-dispersed seeds in intact forest and 77% of seeds in degraded forest lacked fleshy fruit pulp, suggesting ingestion by birds, compared to 0% of all seeds on Guam. Our results show an absence of seed rain in degraded forests on Guam, correlated with the absence of birds, whereas on Saipan, frugivorous birds regularly disperse seeds into degraded forests, providing a mechanism for re-colonization by native plants. These results suggest that loss of frugivores will slow regeneration of degraded forests on Guam.

Diurnal raptors in the fragmented rain forest of the Sierra Imataca, Venezuela

USGS Publications Warehouse

Alvarez, E.; Ellis, D.H.; Smith, D.G.; LaRue, C.T.; Bird, David M.; Varland, Daniel E.; Negro, Juan Jose

1996-01-01

The rain forest of the Sierra Imataca in eastern Venezuela has been subjected to extensive deforestation for pastures and agricultural settlements. In the last decade the opening of access roads combined with intensified logging and mining activities have fragmented a significant portion of the remaining forest. We noted local distribution and habitat use for 42 species of diurnal raptors observed in affected areas in this region. We observed some raptors considered as forest interior species and other open country species foraging and roosting in man-made openings inside the forest.

Functional and environmental determinants of bark thickness in fire-free temperate rain forest communities.

PubMed

Richardson, Sarah J; Laughlin, Daniel C; Lawes, Michael J; Holdaway, Robert J; Wilmshurst, Janet M; Wright, Monique; Curran, Timothy J; Bellingham, Peter J; McGlone, Matt S

2015-10-01

In fire-prone ecosystems, variation in bark thickness among species and communities has been explained by fire frequency; thick bark is necessary to protect cambium from lethal temperatures. Elsewhere this investment is deemed unnecessary, and thin bark is thought to prevail. However, in rain forest ecosystems where fire is rare, bark thickness varies widely among species and communities, and the causes of this variation remain enigmatic. We tested for functional explanations of bark thickness variation in temperate rain forest species and communities. We measured bark thickness in 82 tree species throughout New Zealand temperate rain forests that historically have experienced little fire and applied two complementary analyses. First, we examined correlations between bark traits and leaf habit, and leaf and stem traits. Second, we calculated community-weighted mean (CWM) bark thickness for 272 plots distributed throughout New Zealand to identify the environments in which thicker-barked communities occur. Conifers had higher size-independent bark thickness than evergreen angiosperms. Species with thicker bark or higher bark allocation coefficients were not associated with "slow economic" plant traits. Across 272 forest plots, communities with thicker bark occurred on infertile soils, and communities with thicker bark and higher bark allocation coefficients occurred in cooler, drier climates. In non-fire-prone temperate rain forest ecosystems, investment in bark is driven by soil resources, cool minimum temperatures, and seasonal moisture stress. The role of these factors in fire-prone ecosystems warrants testing. © 2015 Botanical Society of America.

Information for space radar designers: Required dynamic range vs resolution and antenna calibration using the Amazon rain forest

NASA Technical Reports Server (NTRS)

Moore, R. K.; Frost, V. S.

1985-01-01

Calibration of the vertical pattern of the antennas for the SEASAT scatterometer was accomplished using the nearly-uniform radar return from the Amazon rain forest. A similar calibration will be attempted for the SIR-B antenna. Thick calibration is important to establish the radiometric calibration across the swath of the SIR-B, and the developed methodology will provide an important tool in the evaluation of future spaceborne imaging radars. This calibration was made by the very-wide-beam SEASAT scatterometer antennas because at 14.65 GHz the scattering coefficient of the rain forest is almost independent of angle of incidence. It is expected that the variation in scattering coefficient for the rain forest across the relatively narrow vertical beam of the SIR-B will be very small; even at L band the forest should be essentially impenetrable for radar signals, the volume scatter from the treetops will predominate as at higher frequencies. The basic research elements include: (1) examination of SIR-B images over the rain forest to establish the variability of the scattering coefficient at finer resolutions than that of the SEASAT scatterometer; (2) analysis of the variability of SIR-B data detected prior to processing for either azimuth compression or; possibly, range compression so that averages over relatively large footprints can be used; (3) processing of data of the form of (2) using algorithms that can recover the vertical pattern of the antenna.

Holocene rain-forest wilderness: a neotropical perspective on humans as an exotic, invasive species

Treesearch

Robert L. Sanford; Sally P. Horn

2000-01-01

Large areas of lowland tropical rain-forests in the neotropics have been burned over the past 6,000 years, mostly by pre-Colombian agriculturists. This paper presents additional evidence of fires and other human impacts in neotropical forests, and considers the opportunities and limitations of different approaches to determining past land-use “signatures.” Knowledge of...

Long-term changes in structure and composition following hurricanes in a primary lower montane rain forest in Puerto Rico

Treesearch

P.L. Weaver

2013-01-01

Ridges within the lower montane rain forests (sensu Beard) of the Caribbean Basin are dominated by Dacryodes excelsa, a tree species known as tabonuco in Puerto Rico and gommier in the Lesser Antilles. Periodially, hurricanes traverse the islands causing changes in structure, species composition, and dynamics of forests. The chronology of post-hurricane vegetation...

Comparison of direct and indirect methods for assessing leaf area index across a tropical rain forest landscape

Treesearch

Paulo C. Olivas; Steven F. Oberbauer; David B. Clark; Deborah A. Clark; Michael G. Ryan; Joseph J. O' Brien; Harlyn Ordonez

2013-01-01

Many functional properties of forests depend on the leaf area; however, measuring leaf area is not trivial in tall evergreen vegetation. As a result, leaf area is generally estimated indirectly by light absorption methods. These indirect methods are widely used, but have never been calibrated against direct measurements in tropical rain forests, either at point or...

Precipitation nutrients in the open and under two forests in Minnesota

Treesearch

Elon S. Verry; D.R. Timmons

1977-01-01

Concentrations of N, P, K, Ca, Mg, and Na were measured in rain and snow in the open, and in throughfall and stemflow under black spruce and aspen forests in north-central Minnesota. Concentrations of total P in rain and black spruce throughfall were inversely related to storm size. Annual precipitation nutrient inputs to the forest floor were calculated for each site...

Reduced availability of large seeds constrains Atlantic forest regeneration

NASA Astrophysics Data System (ADS)

Costa, Janaina B. P.; Melo, Felipe P. L.; Santos, Bráulio A.; Tabarelli, Marcelo

2012-02-01

Secondary forests are expanding in defaunated fragmented tropical landscapes, but their resilience potential remains poorly understood. In this study we used a chronosequence of advancing (19-62-yr old) Atlantic forest regeneration following slash-and-burn agriculture to infer successional shifts in seed rain in terms of seed density, species richness, taxonomic and functional composition, and local spatial distribution. After monitoring seed rain during 12 months in 60 1-m2 seed traps, we recorded over 400,000 seeds belonging to 180 morphospecies. From early to late-successional stage, seed rain decreased in density, increased in per capita species richness, gradually changed in species composition, and became less aggregated spatially. Regardless the age of forest stand, vertebrate-dispersed seeds accounted for 67-75% of all species recorded. Large-seeded species typical of old-growth forests, on the other hand, accounted for only 5-8% of the species recorded in the seed rain, a proportion around five times smaller than that reported for the old-growth forests of the same study site (31%). Our results suggest that the secondary forests considered, which are embedded in one of the largest (3500 ha) and best preserved remnant of the severely fragmented Atlantic forest of Northeast Brazil, may fail attaining older successional stages due to the reduced availability of large-seeded late-successional species. This regeneration constraint may be even stronger in smaller, more isolated forest remnants of the region, potentially reducing their ability to provide ecosystem services.

Mammals of the Braulio Carrillo- La Selva Complex, Costa Rica

USGS Publications Warehouse

Timm, Robert M.; Wilson, Don E.; Clauson, Barbara L.; LaVal, Richard K.; Vaughan, Christopher S.

1989-01-01

Costa Rica's La Selva-Braulio Carrillo complex encompasses a 60-km protected corridor of Caribbean rain and cloud forest extending from 30 m at the La Selva Biological Station to 2,906 m at the top of Volcán Barva. The 52,000-ha complex covers four life zones and two transitional zones, including tropical wet forest, tropical wet forest cool-transition, tropical premontane wet-transition rain forest, tropical premontane rain forest, lower montane rain forest, and montane rain forest. Located in the northeastern part of the country, the area is representative of Central American Caribbean slope forests that extend from Mexico to Panama. The extensive elevational gradient of the complex provides protected habitat for a variety of altitudinal migrants. With support from the National Geographic Society and Rice Foundation, the Organization for Tropical Studies organized a biological survey of the complex in early 1986. The mammal team worked at six sites along the elevational transect established by the expedition: 300 m, 700 m, 1,000 m, 1,500 m, 2,050 m, and 2,600 m. We supplemented our collecting records with unpublished records made available by colleagues, records in the published literature, and specimens in museum collections. In addition, observations recorded by a variety of observers at the La Selva Biological Station are summarized. The mammal fauna of the complex comprises 142 species including 79 bats, 23 rodents, 15 carnivores, 7 marsupials, 6 edentates, 4 artiodactyls, 3 primates, 2 rabbits, 2 shrews, and 1 perissodactyl. At least 10 additional species are likely to occur there. The only species of mammal likely to have been extirpated from the area is the giant anteater. Recognizing the importance of the area to wildlife and to mankind in general, the government of Costa Rica added 13,500 ha to the complex on 13 April 1986. This area, previously known as the “Zona Protectora,” provided the mid-elevational link between the lowlands of the La Selva Biological Station and the montane forests of Braulio Carrillo National Park. Unfortunately, destruction of the rain forests surrounding the complex will soon render it an isolated island of protected forest. Thus, the area will become increasingly valuable as a refuge for many species with home ranges that require extensive tracts of undisturbed habitat.

Ouragans et diversité biologique dans les forêts tropicales. L'exemple de la Guadeloupe

NASA Astrophysics Data System (ADS)

Imbert, Daniel; Roustéau, Alain; Labbé, Patrick

1998-06-01

In this work, we consider the role played by hurricanes in the maintenance of high biodiversity, ,and we look at how biodiversity may influence the response of tropical forest ecosystems to hurricane disturbances. After hurricane Hugo struck Guadeloupe in 1989, we started a comparative study on the resistance and the resilience of the rain forest, the semi-deciduous forest and the mangrove forest. It appeared that the resistance of these forests was positively linked to their diversity, which was assessed both through flora richness and structure complexity (resultin from the variety of life forms). Examples of species specific resistance or vulnerability occur in the three forests; however, the higher the ecosystem diversity, the fewer and the weaker they are. Abundant species tend to be less vulnerable than others — at least in the rain forest and in the semi-deciduous forest. Forest recovery operates mainly through pre-existing individuals (surviving trees, coppicing stumps, saplings or seedlings). Pioneer species may slightly and temporarily benefit from large openings, especially in the rain forest. Strong recurrence of hurricanes may lead to the extinction of some rare, vulnerable, short-range disseminating, non pioneer species.

Molpa: A newly recorded genus (Orthoptera: Tettigoniidae: Phaneropterinae) from China.

PubMed

Wu, Chao; Yang, Zhen; Liu, Chun-Xiang; Zong, Cheng

2017-12-20

The genus Molpa Walker was previously considered to be disjunctly distributed in broad-leaf rain forests in India and Malaysia. Here we report one new species Molpa dulongensis sp. nov. from subtropic broad-leaf rain forests in southwestern Yunnan Province in China. This is a part of the Indo-Burma biodiversity hotspot area. So we can infer that Molpa is continuously distributed in broad-leaf rain forests found in Oriental Region. Redescription of the genus Molpa and description of the new species Molpa dulongensis sp. nov. are provided. The types are deposited in Insect Collection of Institute of Zoology, Chinese Academy of Sciences, Beijing, China (IZCAS).

When does seed limitation matter for scaling up reforestation from patches to landscapes?

PubMed

Caughlin, T Trevor; Elliott, Stephen; Lichstein, Jeremy W

2016-12-01

Restoring forest to hundreds of millions of hectares of degraded land has become a centerpiece of international plans to sequester carbon and conserve biodiversity. Forest landscape restoration will require scaling up ecological knowledge of secondary succession from small-scale field studies to predict forest recovery rates in heterogeneous landscapes. However, ecological field studies reveal widely divergent times to forest recovery, in part due to landscape features that are difficult to replicate in empirical studies. Seed rain can determine reforestation rate and depends on landscape features that are beyond the scale of most field studies. We develop mathematical models to quantify how landscape configuration affects seed rain and forest regrowth in degraded patches. The models show how landscape features can alter the successional trajectories of otherwise identical patches, thus providing insight into why some empirical studies reveal a strong effect of seed rain on secondary succession, while others do not. We show that seed rain will strongly limit reforestation rate when patches are near a threshold for arrested succession, when positive feedbacks between tree canopy cover and seed rain occur during early succession, and when directed dispersal leads to between-patch interactions. In contrast, seed rain has weak effects on reforestation rate over a wide range of conditions, including when landscape-scale seed availability is either very high or very low. Our modeling framework incorporates growth and survival parameters that are commonly estimated in field studies of reforestation. We demonstrate how mathematical models can inform forest landscape restoration by allowing land managers to predict where natural regeneration will be sufficient to restore tree cover. Translating quantitative forecasts into spatially targeted interventions for forest landscape restoration could support target goals of restoring millions of hectares of degraded land and help mitigate global climate change. © 2016 by the Ecological Society of America.

Rain Forests: Tropical Treasures.

ERIC Educational Resources Information Center

Braus, Judy, Ed.

1989-01-01

Ranger Rick's NatureScope is a creative education series dedicated to inspiring in children an understanding and appreciation of the natural world while developing the skills they will need to make responsible decisions about the environment. The topic of this issue is "Rain Forests: Tropical Treasures." Contents are organized into the…

Prolonged acid rain facilitates soil organic carbon accumulation in a mature forest in Southern China.

PubMed

Wu, Jianping; Liang, Guohua; Hui, Dafeng; Deng, Qi; Xiong, Xin; Qiu, Qingyan; Liu, Juxiu; Chu, Guowei; Zhou, Guoyi; Zhang, Deqiang

2016-02-15

With the continuing increase in anthropogenic activities, acid rain remains a serious environmental threat, especially in the fast developing areas such as southern China. To detect how prolonged deposition of acid rain would influence soil organic carbon accumulation in mature subtropical forests, we conducted a field experiment with simulated acid rain (SAR) treatments in a monsoon evergreen broadleaf forest at Dinghushan National Nature Reserve in southern China. Four levels of SAR treatments were set by irrigating plants with water of different pH values: CK (the control, local lake water, pH ≈ 4.5), T1 (water pH=4.0), T2 (water pH=3.5), and T3 (water pH=3.0). Results showed reduced pH measurements in the topsoil exposed to simulated acid rains due to soil acidification. Soil respiration, soil microbial biomass and litter decomposition rates were significantly decreased by the SAR treatments. As a result, T3 treatment significantly increased the total organic carbon by 24.5% in the topsoil compared to the control. Furthermore, surface soil became more stable as more recalcitrant organic matter was generated under the SAR treatments. Our results suggest that prolonged acid rain exposure may have the potential to facilitate soil organic carbon accumulation in the subtropical forest in southern China. Copyright © 2015 Elsevier B.V. All rights reserved.

Climate, rain shadow, and human-use influences on fire regimes in the eastern Sierra Nevada, California, USA

Treesearch

M.P. North; K.M. van de Water; S.L. Stephens; B.M. Collins

2009-01-01

There have been few fire history studies of eastern Sierra Nevada forests in California, USA, where a steep elevation gradient, rain shadow conditions, and forest stand isolation may produce different fire regimes than those found on the range’s western slope. We investigated historic fire regimes and potential climate influences on four forest types ranging in...

Phosphorus loading to tropical rain forest streams after clear-felling and burning in Sabah, Malaysia

NASA Astrophysics Data System (ADS)

Malmer, Anders

1996-07-01

Most estimates of P export from natural or disturbed humid tropical ecosystems by streams have been based only on export of dissolved P, even though P often is limiting and can be expected to be strongly associated to particles. Therefore loss of ignition (LOI) and particulate P (Ppart) analyses were made on organic and inorganic detritus resulting from surface erosion and on stream-suspended sediments in an undisturbed rain forest (control), as well as during and after conversion of rain forest into forest plantation. Control forest surface erosion and stream sediments consisted mainly of organics, and dissolved P (Pdiss) dominated over Ppart in stream water. The same relation was found after conversion, with a maximum mean Pdiss/Ppart ratio of up to 10 after burning, compared with 2-2.5 for control forests. This larger difference was assumed to depend on PO4 dissolved from ashes to larger concentrations than could be adsorbed during the short time (<1 hour) to reach peak flow during rainstorms.

Daytime turbulent exchange between the Amazon forest and the atmosphere

NASA Technical Reports Server (NTRS)

Fitzjarrald, David R.; Moore, Kathleen E.; Cabral, Osvaldo M. R.; Scolar, Jose; Manzi, Antonio O.; Deabreusa, Leonardo D.

1989-01-01

Detailed observations of turbulence just above and below the crown of the Amazon rain forest during the wet season are presented. The forest canopy is shown to remove high frequency turbulent fluctuations while passing lower frequencies. Filter characteristics of turbulent transfer into the Amazon rain forest canopy are quantified. Simple empirical relations that relate observed turbulent heat fluxes to horizontal wind variance are presented. Changes in the amount of turbulent coupling between the forest and the boundary layer associated with deep convective clouds are presented both as statistical averages and as a series of case studies. These convective processes during the rainy season are shown to alter the diurnal course of turbulent fluxes. In wake of giant coastal systems, no significant heat or moisture fluxes occur for up to a day after the event. Radar data is used to demonstrate that even small raining clouds are capable of evacuating the canopy of substances normally trapped by persistent static stability near the forest floor. Recovery from these events can take more than an hour, even during mid-day. In spite of the ubiquitous presence of clouds and frequent rain during this season, the average horizontal wind speed spectrum is well described by dry CBL similarity hypotheses originally found to apply in flat terrain.

Daytime turbulent exchange between the Amazon forest and the atmosphere

NASA Technical Reports Server (NTRS)

Fitzjarrald, David R.; Moore, Kathleen E.; Cabral, Osvaldo M. R.; Scolar, Jose; Manzi, Antonio

1990-01-01

Detailed observations of turbulence just above and below the crown of the Amazon rain forest during the wet season are presented. The forest canopy is shown to remove high frequency turbulent fluctuations while passing lower frequencies. Filter characteristics of turbulent transfer into the Amazon rain forest canopy are quantified. Simple empirical relations that relate observed turbulent heat fluxes to horizontal wind variance are presented. Changes in the amount of turbulent coupling between the forest and the boundary layer associated with deep convective clouds are presented both as statistical averages and as a series of case studies. These convective processes during the rainy season are shown to alter the diurnal course of turbulent fluxes. In wake of giant coastal systems, no significant heat or moisture fluxes occur for up to a day after the event. Radar data is used to demonstrate that even small raining clouds are capable of evacuating the canopy of substances normally trapped by persistent static stability near the forest floor. Recovery from these events can take more than an hour, even during mid-day. In spite of the ubiquitous presence of clouds and frequent rain during this season, the average horizontal wind speed spectrum is well described by dry CBL similarity hypotheses originally found to apply in flat terrain.

Agaricales Fungi from atlantic rain forest fragments in Minas Gerais, Brazil

PubMed Central

Rosa, Luiz Henrique; Capelari, Marina

2009-01-01

Two Atlantic Rain Forest fragments in Minas Gerais state were studied to access their Agaricales fungal richness. A total of 187 specimens were collected and 109 species, 39 genera, and eight families were identified. Thirty-three species were cited for the first time in Brazil. PMID:24031432

Why Save a Can?

ERIC Educational Resources Information Center

Gutierrez, Melida; Johnson, Cheryl

2009-01-01

This activity ties together the recycling of aluminum and the protection of rain forests. Students use critical thinking to study the effects of open pit mining of bauxite in rain forests and then draw their own conclusions about how to minimize the impact of bauxite mining and boost recycling efforts within their communities. Drawing conclusions…

The Importance of the Nothofagus Forest on Snowmelt Process linked to floods in Mountain Basins of Tierra del Fuego, Argentina as Input for Land Use Policies.

NASA Astrophysics Data System (ADS)

Iturraspe, R. J.; Urciuolo, A. B.; Lofiego, R.

2007-05-01

The conception and application of policies and best practices for the appropriate land use from the view point of extreme floods attenuation, must be based on scientist acknowledge of the basin response, reaching each one of the hydrological cycle's components. That condition is necessary as a start point for an integrated intersectoral management of water and forest resources at the basin scale, especially when forest logging or forest urbanization appear as land use alternatives with socioeconomic importance, confronting the natural roll of the forest in the basin. Within this framework, this article analyzes the forest importance on the seasonal snow-pack and snow-melting process in the mountain basin environment of Tierra del Fuego Island, Argentina, where a mixed rain-snow hydrological regimen and a canopy of native Nothofagus forest are basic features considered. Extreme floods events are related to heavy rain and snow-melting combination. In theory, the worst scenario is the exceptional rain occurrence at the moment of the maximum snow storage, air temperature higher than 0ºC in the whole basin, and previous wet conditions. On this scenario we analyze aspects that indicate forest influences on the snow pack distribution and evolution which are favorable to the attenuation of the intensity of melting process which are induced by rain and temperate air mass. Results were obtained in the context of the EPIC FORCE (EU) Project.

Reconstructed high-resolution scatterometer data: a comparison with AVHRR vegetation index images for regional-scale monitoring of tropical rain forests

NASA Astrophysics Data System (ADS)

Hardin, Perry J.; Long, David G.

1993-08-01

There is considerable interest in utilizing microwave and visible spectrum imagery for the assessment of tropical rain forests. Because rain forest spans large sub-continental areas, medium resolution (1 - 16 km) imagery will play an important role in providing a global perspective of any forest removal or change. Since 1978, AVHRR imagery from NOAA polar orbiters has provided coverage of tropical regions at this desirable resolution, but much of the imagery is plagued with heavy cloud cover typical of equatorial regions. In contrast, no historical source of active microwave imagery at native 1 - 16 km resolution exists for all the global rain forest regions. In this paper, the authors compare the utility of Seasat scatterometer (SASS) ku-band microwave data to early-date AVHRR vegetation index products for discrimination of tropical vegetation formations. When considered separately, both the AVHRR imagery and the SASS imagery could be used to distinguish between broad categories of equatorial land cover, but the AVHRR imagery was slightly superior. When combined, the two data sets provided discrimination capability superior than could be obtained by using either set alone.

Biomass and carbon dynamics of a tropical mountain rain forest in China.

PubMed

Chen, DeXiang; Li, YiDe; Liu, HePing; Xu, Han; Xiao, WenFa; Luo, TuShou; Zhou, Zhang; Lin, MingXian

2010-07-01

Biometric inventories for 25 years, from 1983 to 2005, indicated that the Jianfengling tropical mountain rain forest in Hainan, China, was either a source or a modest sink of carbon. Overall, this forest was a small carbon sink with an accumulation rate of (0.56+/-0.22) Mg C ha(-1)yr(-1), integrated from the long-term measurement data of two plots (P9201 and P8302). These findings were similar to those for African and American rain forests ((0.62+/-0.23) Mg C ha(-1)yr(-1)). The carbon density varied between (201.43+/-29.38) Mg C ha(-1) and (229.16+/-39.2) Mg C ha(-1), and averaged (214.17+/-32.42) Mg C ha(-1) for plot P9201. Plot P8302, however, varied between (223.95+/-45.92) Mg C ha(-1) and (254.85+/-48.86) Mg C ha(-1), and averaged (243.35+/-47.64) Mg C ha(-1). Quadratic relationships were found between the strength of carbon sequestration and heavy rainstorms and dry months. Precipitation and evapotranspiration are two major factors controlling carbon sequestration in the tropical mountain rain forest.

Forest and community structure of tropical sub-montane rain forests on the island of Dominica, Lesser Antilles

Treesearch

S.J. DeWalt; K. Ickes; A. James

2016-01-01

To examine short- and long-term changes in hurricane-prone sub-montane rain forests on Dominica in the Lesser Antilles of the eastern Caribbean, we established 17 permanent, 0.25-ha vegetation plots clustered in 3 regions of the island—northeast, northwest, and southwest. We counted all trees ≥10 cm diameter almost 30 years after Hurricane David caused substantial tree...

Links to Literature--Huge Trees, Small Drawings: Ideas of Relative Sizes.

ERIC Educational Resources Information Center

Burton, Gail

1996-01-01

Discusses a unit integrating science, mathematics, and environmental education centered around "The Great Kapok Tree," by Lynne Cherry (1990). Ratios are used to make scale drawings of trees in a rain forest. Other activities include a terrarium and problem-solving activities based on eating habits of rain forest animals. (KMC)

Tropical secondary forest management influences frugivorous bat composition, abundance and fruit consumption in Chiapas, Mexico.

PubMed

Vleut, Ivar; Levy-Tacher, Samuel Israel; de Boer, Willem Frederik; Galindo-González, Jorge; Vazquez, Luis-Bernardo

2013-01-01

Most studies on frugivorous bat assemblages in secondary forests have concentrated on differences among successional stages, and have disregarded the effect of forest management. Secondary forest management practices alter the vegetation structure and fruit availability, important factors associated with differences in frugivorous bat assemblage structure, and fruit consumption and can therefore modify forest succession. Our objective was to elucidate factors (forest structural variables and fruit availability) determining bat diversity, abundance, composition and species-specific abundance of bats in (i) secondary forests managed by Lacandon farmers dominated by Ochroma pyramidale, in (ii) secondary forests without management, and in (iii) mature rain forests in Chiapas, Southern Mexico. Frugivorous bat species diversity (Shannon H') was similar between forest types. However, bat abundance was highest in rain forest and O. pyramidale forests. Bat species composition was different among forest types with more Carollia sowelli and Sturnira lilium captures in O. pyramidale forests. Overall, bat fruit consumption was dominated by early-successional shrubs, highest late-successional fruit consumption was found in rain forests and more bats consumed early-successional shrub fruits in O. pyramidale forests. Ochroma pyramidale forests presented a higher canopy openness, tree height, lower tree density and diversity of fruit than secondary forests. Tree density and canopy openness were negatively correlated with bat species diversity and bat abundance, but bat abundance increased with fruit abundance and tree height. Hence, secondary forest management alters forests' structural characteristics and resource availability, and shapes the frugivorous bat community structure, and thereby the fruit consumption by bats.

A long pollen record from lowland Amazonia: Forest and cooling in glacial times

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

Colinvaux, P.A.; Moreno, J.E.; Bush, M.B.

A continuous pollen history of more than 40,000 years was obtained from a lake in the lowland Amazon rain forest. Pollen spectra demonstrate that tropical rain forest occupied the region continuously and that savannas or grasslands were not present during the last glacial maximum. The data suggest that the western Amazon forest was not fragmented into refugia in glacial times and that the lowlands were not a source of dust. Glacial age forests were comparable to modern forests but also included species now restricted to higher evaluations by temperature, suggesting a cooling of the order of 5{degrees} to 6{degrees}C. 23more » refs., 22 tabs.« less

Tropical Secondary Forest Management Influences Frugivorous Bat Composition, Abundance and Fruit Consumption in Chiapas, Mexico

PubMed Central

Vleut, Ivar; Levy-Tacher, Samuel Israel; de Boer, Willem Frederik; Galindo-González, Jorge; Vazquez, Luis-Bernardo

2013-01-01

Most studies on frugivorous bat assemblages in secondary forests have concentrated on differences among successional stages, and have disregarded the effect of forest management. Secondary forest management practices alter the vegetation structure and fruit availability, important factors associated with differences in frugivorous bat assemblage structure, and fruit consumption and can therefore modify forest succession. Our objective was to elucidate factors (forest structural variables and fruit availability) determining bat diversity, abundance, composition and species-specific abundance of bats in (i) secondary forests managed by Lacandon farmers dominated by Ochroma pyramidale, in (ii) secondary forests without management, and in (iii) mature rain forests in Chiapas, Southern Mexico. Frugivorous bat species diversity (Shannon H’) was similar between forest types. However, bat abundance was highest in rain forest and O. pyramidale forests. Bat species composition was different among forest types with more Carollia sowelli and Sturnira lilium captures in O. pyramidale forests. Overall, bat fruit consumption was dominated by early-successional shrubs, highest late-successional fruit consumption was found in rain forests and more bats consumed early-successional shrub fruits in O. pyramidale forests. Ochroma pyramidale forests presented a higher canopy openness, tree height, lower tree density and diversity of fruit than secondary forests. Tree density and canopy openness were negatively correlated with bat species diversity and bat abundance, but bat abundance increased with fruit abundance and tree height. Hence, secondary forest management alters forests’ structural characteristics and resource availability, and shapes the frugivorous bat community structure, and thereby the fruit consumption by bats. PMID:24147029

How does tree age influence damage and recovery in forests impacted by freezing rain and snow?

PubMed

Zhu, LiRong; Zhou, Ting; Chen, BaoMing; Peng, ShaoLin

2015-05-01

The response and recovery mechanisms of forests to damage from freezing rain and snow events are a key topic in forest research and management. However, the relationship between the degree of damage and tree age, i.e., whether seedlings, young trees, or adult trees are most vulnerable, remains unclear and is rarely reported. We investigated the effect of tree age on the degrees of vegetation damage and subsequent recovery in three subtropical forest types-coniferous, mixed, and broad-leaved-in the Tianjing Mountains, South China, after a series of rare icy rain and freezing snow events in 2008. The results showed that damage and recovery rates were both dependent on tree age, with the proportion of damaged vegetation increasing with age (estimated by diameter at breast height, DBH) in all three forest types and gradually plateauing. Significant variation occurred among forest types. Young trees in the coniferous forest were more vulnerable than those in the broad-leaved forest. The type of damage also varied with tree age in different ways in the three forest types. The proportion of young seedlings that were uprooted (the most severe type of damage) was highest in the coniferous forest. In the mixed forest, young trees were significantly more likely to be uprooted than seedlings and adult trees, while in the broad-leaved forest, the proportion of uprooted adult trees was significantly higher than that of seedlings and young trees. There were also differences among forest types in how tree age affected damage recovery. In the coniferous forest, the recovery rate of trees with broken trunks or crowns (DBH > 2.5 cm) increased with tree age. However, in the mixed and broad-leaved forests, no obvious correlation between the recovery rate of trees with broken trunks or crowns and tree age was observed. Trees with severe root damage did not recover; they were uprooted and died. In these forests, vegetation damage and recovery showed tree age dependencies, which varied with tree shape, forest type, and damage type. Understanding this dependency will guide restoration after freezing rain and snow disturbances.

Amazon Rain Forest Classification Using J-ERS-1 SAR Data

NASA Technical Reports Server (NTRS)

Freeman, A.; Kramer, C.; Alves, M.; Chapman, B.

1994-01-01

The Amazon rain forest is a region of the earth that is undergoing rapid change. Man-made disturbance, such as clear cutting for agriculture or mining, is altering the rain forest ecosystem. For many parts of the rain forest, seasonal changes from the wet to the dry season are also significant. Changes in the seasonal cycle of flooding and draining can cause significant alterations in the forest ecosystem.Because much of the Amazon basin is regularly covered by thick clouds, optical and infrared coverage from the LANDSAT and SPOT satellites is sporadic. Imaging radar offers a much better potential for regular monitoring of changes in this region. In particular, the J-ERS-1 satellite carries an L-band HH SAR system, which via an on-board tape recorder, can collect data from almost anywhere on the globe at any time of year.In this paper, we show how J-ERS-1 radar images can be used to accurately classify different forest types (i.e., forest, hill forest, flooded forest), disturbed areas such as clear cuts and urban areas, and river courses in the Amazon basin. J-ERS-1 data has also shown significant differences between the dry and wet season, indicating a strong potential for monitoring seasonal change. The algorithm used to classify J-ERS-1 data is a standard maximum-likelihood classifier, using the radar image local mean and standard deviation of texture as input. Rivers and clear cuts are detected using edge detection and region-growing algorithms. Since this classifier is intended to operate successfully on data taken over the entire Amazon, several options are available to enable the user to modify the algorithm to suit a particular image.

Comparative effects of simulated acid rain of different ratios of SO42- to NO3- on fine root in subtropical plantation of China.

PubMed

Liu, Xin; Zhao, Wenrui; Meng, Miaojing; Fu, Zhiyuan; Xu, Linhao; Zha, Yan; Yue, Jianmin; Zhang, Shuifeng; Zhang, Jinchi

2018-03-15

The influence of acid rain on forest trees includes direct effects on foliage as well as indirect soil-mediated effects that cause a reduction in fine-root growth. In addition, the concentration of NO 3 - in acid rain increases with the rapidly growing of nitrogen deposition. In this study, we investigated the impact of simulated acid rain with different SO 4 2- /NO 3 - (S/N) ratios, which were 5:1 (S), 1:1 (SN) and 1:5 (N), on fine-root growth from March 2015 to February 2016. Results showed that fine roots were more sensitive to the effects of acid rain than soils in the short-term. Both soil pH and fine root biomass (FRB) significantly decreased as acid rain pH decreased, and also decreased with the percentage of NO 3 - increased in acid rain. Acid rain pH significantly influenced soil total carbon and available potassium in summer. Higher acidity level (pH=2.5), especially of the N treatments, had the strongest inhibitory impact on soil microbial activity after summer. The structural equation modelling results showed that acid rain S/N ratio and pH had stronger direct effects on FRB than indirect effects via changed soil and fine root properties. Fine-root element contents and antioxidant enzymes activities were significantly affected by acid rain S/N ratio and pH during most seasons. Fine-root Al ion content, Ca/Al, Mg/Al ratios and catalase activity were used as better indicators than soil parameters for evaluating the effects of different acid rain S/N ratios and pH on forests. Our results suggest that the ratio of SO 4 2- to NO 3 - in acid rain is an important factor which could affect fine-root growth in subtropical forests of China. Copyright © 2017. Published by Elsevier B.V.

Land-use systems and resilience of tropical rain forests in the Tehuantepec Isthmus, Mexico.

PubMed

García-Romero, Arturo; Oropeza-Orozco, Oralia; Galicia-Sarmiento, Leopoldo

2004-12-01

Land-cover types were analyzed for 1970, 1990 and 2000 as the bases for determining land-use systems and their influence on the resilience of tropical rain forests in the Tehuantepec Isthmus, Mexico. Deforestation (DR) and mean annual transformation rates were calculated from land-cover change data; thus, the classification of land-use change processes was determined according to their impact on resilience: a) Modification, including land-cover conservation and intensification, and b) Conversion, including disturbance and regeneration processes. Regeneration processes, from secondary vegetation under extensive use, cultivated vegetation under intensive use, and cultivated or induced vegetation under extensive use to mature or secondary vegetation, have high resilience capacity. In contrast, cattle-raising is characterized by rapid expansion, long-lasting change, and intense damages; thus, recent disturbance processes, which include the conversion to cattle-raising, provoke the downfall of the traditional agricultural system, and nullify the capacity of resilience of tropical rain forest. The land-use cover change processes reveal a) the existence of four land-use systems (forestry, extensive agriculture, extensive cattle-raising, and intensive uses) and b) a trend towards the replacement of agricultural and forestry systems by extensive cattle-raising, which was consolidated during 1990-2000 (DR of evergreen tropical rain forest = 4.6%). Only the forestry system, which is not subject to deforestation, but is affected by factors such as selective timber, extraction, firewood collection, grazing, or human-induced fire, is considered to have high resilience (2 years), compared to agriculture (2-10 years) or cattle-raising (nonresilient). It is concluded that the analysis of land-use systems is essential for understanding the implications of land-use cover dynamics on forest recovery and land degradation in tropical rain forests.

Pennsylvanian tropical rain forests responded to glacial-interglacial rhythms

NASA Astrophysics Data System (ADS)

Falcon-Lang, Howard J.

2004-08-01

Pennsylvanian tropical rain forests flourished during an icehouse climate mode. Although it is well established that Milankovitch-band glacial-interglacial rhythms caused marked synchronous changes in Pennsylvanian tropical climate and sea level, little is known of vegetation response to orbital forcing. This knowledge gap has now been addressed through sequence- stratigraphic analysis of megafloral and palynofloral assemblages within the Westphalian D Cantabrian Sydney Mines Formation of eastern Canada. This succession was deposited in a low- accommodation setting where sequences can be attributed confidently to glacio-eustasy. Results show that long-lived, low-diversity peat mires dominated by lycopsids were initiated during deglaciation events, but were mostly drowned by rising sea level at maximum interglacial conditions. Only upland coniferopsid forests survived flooding without significant disturbance. Mid- to late interglacial phases witnessed delta-plain progradation and establishment of high-diversity, mineral-substrate rain forests containing lycopsids, sphenopsids, pteridosperms, cordaites, and tree ferns. Renewed glaciation resulted in sea-level fall, paleovalley incision, and the onset of climatic aridity. Glacial vegetation was dominated by cordaites, pteridosperms, and tree ferns; hydrophilic lycopsids and sphenopsids survived in paleovalley refugia. Findings clearly demonstrate the dynamic nature of Pennsylvanian tropical ecosystems and are timely given current debates about the impact of Quaternary glacial-interglacial rhythms on the biogeography of tropical rain forest.

Correlates of microhabitat use and density of Clethrionomys gapperi and Peromyscus keeni in temperate rain forests of Southeast Alaska.

Treesearch

Winston P. Smith; Scott M. Gende; Jeffrey V. Nichols

2005-01-01

We studied red-backed vole Clethrionomys gapperi and Keen' s mouse Peromyscus keeni populations in the Alexander Archipelago to test predictions regarding habitat relations in temperate rain forest of southeastern Alaska during August - September 1998 and 2000 and April - May 1999 and 2000. We measured 26 vegetative and...

Herbicides for site preparation...broadcast spray by mist blower tested against understory in Hawaii rain forest

Treesearch

Stanley B. Carpenter

1966-01-01

Two studies started in 1964 tested control of dense understory vegetation in Hawaii rain forests with herbicides applied by a large turbine blower spraying from widely spaced bulldozer lines. Brushkiller and Tordon 101 were effective on shrubs. Results on treefern were poor, but encouraging enough to merit additional study.

Environmental and biotic controls over aboveground biomass throughout a tropical rainforest

Treesearch

G.P. Asner; R.F. Hughes; T.A. Varga; D.E. Knapp; T. Kennedy-Bowdoin

2009-01-01

The environmental and biotic factors affecting spatial variation in canopy three-dimensional (3-D) structure and aboveground tree biomass (AGB) are poorly understood in tropical rain forests. We combined field measurements and airborne light detection and ranging (lidar) to quantify 3-D structure and AGB across a 5,016 ha rain forest reserve on the...

Searching for signatures across microbial communities: Metagenomic analysis of soil samples from mangrove and other ecosystems.

PubMed

Imchen, Madangchanok; Kumavath, Ranjith; Barh, Debmalya; Azevedo, Vasco; Ghosh, Preetam; Viana, Marcus; Wattam, Alice R

2017-08-18

In this study, we categorize the microbial community in mangrove sediment samples from four different locations within a vast mangrove system in Kerala, India. We compared this data to other samples taken from the other known mangrove data, a tropical rainforest, and ocean sediment. An examination of the microbial communities from a large mangrove forest that stretches across southwestern India showed strong similarities across the higher taxonomic levels. When ocean sediment and a single isolate from a tropical rain forest were included in the analysis, a strong pattern emerged with Bacteria from the phylum Proteobacteria being the prominent taxon among the forest samples. The ocean samples were predominantly Archaea, with Euryarchaeota as the dominant phylum. Principal component and functional analyses grouped the samples isolated from forests, including those from disparate mangrove forests and the tropical rain forest, from the ocean. Our findings show similar patterns in samples were isolated from forests, and these were distinct from the ocean sediment isolates. The taxonomic structure was maintained to the level of class, and functional analysis of the genes present also displayed these similarities. Our report for the first time shows the richness of microbial diversity in the Kerala coast and its differences with tropical rain forest and ocean microbiome.

On the potential of long wavelength imaging radars for mapping vegetation types and woody biomass in tropical rain forests

NASA Technical Reports Server (NTRS)

Rignot, Eric J.; Zimmermann, Reiner; Oren, Ram

1995-01-01

In the tropical rain forests of Manu, in Peru, where forest biomass ranges from 4 kg/sq m in young forest succession up to 100 kg/sq m in old, undisturbed floodplain stands, the P-band polarimetric radar data gathered in June of 1993 by the AIRSAR (Airborne Synthetic Aperture Radar) instrument separate most major vegetation formations and also perform better than expected in estimating woody biomass. The worldwide need for large scale, updated biomass estimates, achieved with a uniformly applied method, as well as reliable maps of land cover, justifies a more in-depth exploration of long wavelength imaging radar applications for tropical forests inventories.

The northern flying squirrel as an indicator species of temperate rain forest: test of an hypothesis.

Treesearch

Winston P. Smith; Scott M. Gende; Jeffrey V. Nichols

2005-01-01

Management indicator species (MIS) often are selected because their life history and demographics are thought to reflect a suite of ecosystem conditions that are too difficult or costly to measure directly. The northern flying squirrel (Glaucomys sabrinus) has been proposed as an MIS of temperate rain forest of southeastern Alaska based on previous...

The effects of acid rain on nitrogen fixation in Western Washington coniferous forests

Treesearch

Robert Denison; Bruce Caldwell; Bernard Bormann; Lindell Eldred; Cynthia Swanberg; Steven Anderson

1976-01-01

We investigated both the current status of nitrogen fixation in Western Washington forests, and the potential effects of acid rain on this vital process. Even the low concentrations of sulfur dioxide presently found in the Northwest are thought to have an adverse effect on nitrogen fixation by limiting the distribution of the epiphytic nitrogen-fixing lichen, ...

Physical hydrology and the effects of forest harvesting in the Pacific Northwest: a review.

Treesearch

R. Dan Moore; S.M. Wondzell

2005-01-01

The Pacific Northwest encompasses a range of hydrologic regimes that can be broadly characterized as either coastal (where rain and rain on snow are dominant) or interior (where snowmelt is dominant). Forest harvesting generally increases the fraction of precipitation that is available to become streamflow, increases rates of snowmelt, and modifies the runoff pathways...

Rain Forest Tourism - Estimating the Benefits of Tourism Development in a New National Park in Madagascar

Treesearch

D. Evan Mercer; R. Kramer; N. Sharma

1995-01-01

Travel cost and contingent valuation methods are applied to the problem of estimating the potential consumer surplus available to international nature tourists from a rain forest conservation project in Madagascar. Data are derived from surveys of nature tourists in Madagascar and international, nature tourism professionals in the U.S. and Europe. Typical trip travel...

Los Arboles Hablan: A Spanish Language Curriculum Unit Based on the Study of Latin American Rain Forests.

ERIC Educational Resources Information Center

Zuman, John P.

"Los Arboles Hablan," a video-based curriculum that promotes the learning of Spanish as a second language through study of the Latin American rain forests is described. The 12-session unit was designed for use at the middle school level and integrates science, social science, and environmental education with content focusing on the…

Water, water everywhere: subtle shifts in soil saturation drive ecological function in coastal rain forests

Treesearch

Marie Oliver; David D' Amore

2015-01-01

New research reveals how topography, soil temperature, and subtle shifts in soil drainage are key drivers in ecosystem function in the coastal temperate rain forests of southeast Alaska and British Columbia. These studies, by Dave D'Amore and his colleagues, provide a better understanding of the influence of soil hydrology on dissolved organic carbon export and...

Postfire seed rain of black spruce, a semiserotinous conifer, in forests of interior Alaska

Treesearch

Jill Johnstone; Leslie Boby; Emily Tissier; Michelle Mack; Dave Verbyla; Xanthe. Walker

2009-01-01

The availability of viable seed can act as an important constraint on plant regeneration following disturbance. This study presents data on seed quantity and quality for black spruce (Picea mariana (Mill.) B.S.P.), a semiserotinous conifer that dominates large areas of North American boreal forest. We sampled seed rain and viability for 2 years...

Rain forest promotes trophic interactions and diversity of trap-nesting Hymenoptera in adjacent agroforestry.

PubMed

Klein, Alexandra-Maria; Steffan-Dewenter, Ingolf; Tscharntke, Teja

2006-03-01

1. Human alteration of natural ecosystems to agroecosystems continues to accelerate in tropical countries. The resulting world-wide decline of rain forest causes a mosaic landscape, comprising simple and complex agroecosystems and patchily distributed rain forest fragments of different quality. Landscape context and agricultural management can be expected to affect both species diversity and ecosystem services by trophic interactions. 2. In Central Sulawesi, Indonesia, 24 agroforestry systems, differing in the distance to the nearest natural forest (0-1415 m), light intensity (37.5-899.6 W/m(-2)) and number of vascular plant species (7-40 species) were studied. Ten standardized trap nests for bees and wasps, made from reed and knotweed internodes, were exposed in each study site. Occupied nests were collected every month, over a period totalling 15 months. 3. A total of 13,617 brood cells were reared to produce adults of 14 trap-nesting species and 25 natural enemy species, which were mostly parasitoids. The total number of species was affected negatively by increasing distance from forest and increased with light intensity of agroforestry systems. The parasitoids in particular appeared to benefit from nearby forests. Over a 500-m distance, the number of parasitoid species decreased from eight to five, and parasitism rates from 12% to 4%. 4. The results show that diversity and parasitism, as a higher trophic interaction and ecosystem service, are enhanced by (i) improved connectivity of agroecosystems with natural habitats such as agroforestry adjacent to rain forest and (ii) management practices to increase light availability in agroforestry, which also enhances richness of flowering plants in the understorey.

Degradation of Root Community Traits as Indicator for Transformation of Tropical Lowland Rain Forests into Oil Palm and Rubber Plantations

PubMed Central

Edy, Nur; Meyer, Marike; Corre, Marife D.; Polle, Andrea

2015-01-01

Conversion of tropical forests into intensely managed plantations is a threat to ecosystem functions. On Sumatra, Indonesia, oil palm (Elaeis guineensis) plantations are rapidly expanding, displacing rain forests and extensively used rubber (Hevea brasiliensis) agro-forests. Here, we tested the influence of land use systems on root traits including chemical traits (carbon, nitrogen, mineral nutrients, potentially toxic elements [aluminium, iron] and performance traits (root mass, vitality, mycorrhizal colonization). Traits were measured as root community-weighed traits (RCWTs) in lowland rain forests, in rubber agro-forests mixed with rain forest trees, in rubber and oil palm plantations in two landscapes (Bukit Duabelas and Harapan, Sumatra). We hypothesized that RCWTs vary with land use system indicating increasing transformation intensity and loss of ecosystem functions. The main factors found to be related to increasing transformation intensity were declining root vitality and root sulfur, nitrogen, carbon, manganese concentrations and increasing root aluminium and iron concentrations as well as increasing spore densities of arbuscular mycorrhizas. Mycorrhizal abundance was high for arbuscular and low for ectomycorrhizas and unrelated to changes in RCWTs. The decline in RCWTs showed significant correlations with soil nitrogen, soil pH and litter carbon. Thus, our study uncovered a relationship between deteriorating root community traits and loss of ecosystem functionality and showed that increasing transformation intensity resulted in decreasing root nutrition and health. Based on these results we suggest that land management that improves root vitality may enhance the ecological functions of intense tropical production systems. PMID:26366576

Degradation of Root Community Traits as Indicator for Transformation of Tropical Lowland Rain Forests into Oil Palm and Rubber Plantations.

PubMed

Sahner, Josephine; Budi, Sri Wilarso; Barus, Henry; Edy, Nur; Meyer, Marike; Corre, Marife D; Polle, Andrea

2015-01-01

Conversion of tropical forests into intensely managed plantations is a threat to ecosystem functions. On Sumatra, Indonesia, oil palm (Elaeis guineensis) plantations are rapidly expanding, displacing rain forests and extensively used rubber (Hevea brasiliensis) agro-forests. Here, we tested the influence of land use systems on root traits including chemical traits (carbon, nitrogen, mineral nutrients, potentially toxic elements [aluminium, iron] and performance traits (root mass, vitality, mycorrhizal colonization). Traits were measured as root community-weighed traits (RCWTs) in lowland rain forests, in rubber agro-forests mixed with rain forest trees, in rubber and oil palm plantations in two landscapes (Bukit Duabelas and Harapan, Sumatra). We hypothesized that RCWTs vary with land use system indicating increasing transformation intensity and loss of ecosystem functions. The main factors found to be related to increasing transformation intensity were declining root vitality and root sulfur, nitrogen, carbon, manganese concentrations and increasing root aluminium and iron concentrations as well as increasing spore densities of arbuscular mycorrhizas. Mycorrhizal abundance was high for arbuscular and low for ectomycorrhizas and unrelated to changes in RCWTs. The decline in RCWTs showed significant correlations with soil nitrogen, soil pH and litter carbon. Thus, our study uncovered a relationship between deteriorating root community traits and loss of ecosystem functionality and showed that increasing transformation intensity resulted in decreasing root nutrition and health. Based on these results we suggest that land management that improves root vitality may enhance the ecological functions of intense tropical production systems.

[Relationships between soil moisture and needle-fall in Masson pine forests in acid rain region of Chongqing, Southwest China].

PubMed

Wang, Yi-Hao; Wang, Yan-Hui; Li, Zhen-Hua; Yu, Peng-Tao; Xiong, Wei; Hao, Jia; Duan, Jian

2012-10-01

From March 2009 to November 2011, an investigation was conducted on the spatiotemporal variation of soil moisture and its effects on the needle-fall in Masson pine (Pinus massoniana) forests in acid rain region of Chongqing, Southeast China, with the corresponding soil moisture thresholds determined. No matter the annual precipitation was abundant, normal or less than average, the seasonal variation of soil moisture in the forests could be obviously divided into four periods, i.e., sufficient (before May), descending (from June to July), drought (from August to September), and recovering (from October to November). With increasing soil depth, the soil moisture content increased after an initial decrease, but the difference of the soil moisture content among different soil layers decreased with decreasing annual precipitation. The amount of monthly needle-fall in the forests in growth season was significantly correlated with the water storage in root zone (0-60 cm soil layer), especially in the main root zone (20-50 cm soil layer). Soil field capacity (or capillary porosity) and 82% of field capacity (or 80% of capillary porosity) were the main soil moisture thresholds affecting the litter-fall. It was suggested that in acid rain region, Masson pine forest was easily to suffer from water deficit stress, especially in dry-summer period. The water deficit stress, together with already existed acid rain stress, would further threaten the health of the Masson forest.

Methods for measuring bird-mediated seed rain: Insights from a Hawaiian mesic forest

USGS Publications Warehouse

Rose, Eli; Stewart, Meredith; Brinkman, Andrew; Paxton, Eben H.; Yelenik, Stephanie G.

2017-01-01

Amount and diversity of bird-dispersed seed rain play important roles in determining forest composition, yet neither is easy to quantify. The complex ecological processes that influence seed movement make the best approach highly context specific. Although recent advances in seed rain theory emphasize quantifying source-specific seed shadows, many ecological questions can be addressed u sing a less mechanistic approach that requires fewer assumptions. Using seed rain rates from 0.38 m2 hoop traps sampled twice monthly over the course of a year, we show that number of traps required to identify changes in seed rain varies across seed species and forest type. Detecting a 50% increase in amount of seed rain required from 65 to >300 traps, while detecting a 200% increase generally required ≤⃒50 traps. Trap size and ecological context dictate the number of seeds found in each trap, but the coefficient of variation (CV) across traps in a given ecological context can help inform future studies about number of traps needed to detect change. To better understand factors influencing variation around estimates of seed rain, we simulated both clustered and evenly distributed patterns of fecal deposition using three different levels of seed aggregation (number of seeds in each fecal deposit). When patterns of fecal deposition were clustered, rather than evenly dispersed across the study area, they required >1.5 times the number of traps to identify a 100% increase in seed rain. Similarly, we found that low seed aggregation required >1.5 times the number of traps to detect a 100% change than when aggregation was medium or high. At low aggregations, fewer seed rain traps contained seeds (low, 33 ± 5%; medium, 23 ± 4%; high, 24 ± 5%), resulting in more variation across traps than medium and high aggregations. We also illustrate the importance of training observers to discern between morphologically similar seeds from different species and provide resources to help identify bird-dispersed seeds commonly found within midelevation mesic Hawaiian forests.

Deforestation, fire susceptibility, and potential tree responses to fire in the eastern Amazon

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

Uhl, C.; Kauffman, J.B.

1990-04-01

In the state of Para, Brazil, in the eastern Amazon, the authors studied the potential for sustained fire events within four dominant vegetation cover types (undisturbed rain forest, selectively logged forest, second-growth forest, and open pasture), by measuring fuel availability, microclimate, and rates of fuel moisture loss. They also estimated the potential tree mortality that might result from a wide-scale Amazon forest fire by measuring the thermal properties of bark for all trees in a 5-ha stand of mature forest, followed by measurements of heat flux through bark during simulated fires. In pastures the average midday temperature was almost 10{degree}Cmore » greater and the average midday relative humidity was 30% lower than in primary forest. The most five-prone ecosystem was the open pasture followed by selectively logged forest, second growth forest, and undisturbed rain forest in which sustained combustion was not possible even after prolonged rainless periods. Even though the autogenic factors in primary forest of the eastern Amazon create a microclimate that virtually eliminates the probability of fire, they are currently a common event in disturbed areas of Amazonia. As many as 8 {times} 10{sup 6} ha burned in the Amazon Basin of Brazil in 1987 alone. In terms of current land-use patterns, altered microclimates, and fuel mass, there are also striking similarities between the eastern Amazon and East Kalimantan, Indonesia (the site of recent rain forest wildfires that burned 3.5 {times} 10{sup 6} ha).« less

Invasive plants transform the three-dimensional structure of rain forests

PubMed Central

Asner, Gregory P.; Hughes, R. Flint; Vitousek, Peter M.; Knapp, David E.; Kennedy-Bowdoin, Ty; Boardman, Joseph; Martin, Roberta E.; Eastwood, Michael; Green, Robert O.

2008-01-01

Biological invasions contribute to global environmental change, but the dynamics and consequences of most invasions are difficult to assess at regional scales. We deployed an airborne remote sensing system that mapped the location and impacts of five highly invasive plant species across 221,875 ha of Hawaiian ecosystems, identifying four distinct ways that these species transform the three-dimensional (3D) structure of native rain forests. In lowland to montane forests, three invasive tree species replace native midcanopy and understory plants, whereas one understory invader excludes native species at the ground level. A fifth invasive nitrogen-fixing tree, in combination with a midcanopy alien tree, replaces native plants at all canopy levels in lowland forests. We conclude that this diverse array of alien plant species, each representing a different growth form or functional type, is changing the fundamental 3D structure of native Hawaiian rain forests. Our work also demonstrates how an airborne mapping strategy can identify and track the spread of certain invasive plant species, determine ecological consequences of their proliferation, and provide detailed geographic information to conservation and management efforts. PMID:18316720

Arbuscular mycorrhizal fungi in the tree seedlings of two Australian rain forests: occurrence, colonization, and relationships with plant performance.

PubMed

Gehring, Catherine A; Connell, Joseph H

2006-03-01

The roots of rain forest plants are frequently colonized by arbuscular mycorrhizal fungi (AMF) that can promote plant growth in the nutrient poor soils characteristic of these forests. However, recent studies suggest that both the occurrence of AMF on rain forest plants and the dependence of rain forest plants on AMF can be highly variable. We examined the occurrence and levels of AMF colonization of some common seedling species in a tropical and a subtropical rain forest site in Queensland, Australia. We also used a long-term database to compare the growth and mortality rates of seedling species that rarely formed AMF with those that regularly formed AMF. In both forests, more than one-third of the seedling species rarely formed AMF associations, while 40% of species consistently formed AMF in the tropical site compared to 27% in the subtropical site. Consistent patterns of AMF occurrence were observed among plant families at the two sites. Variation among seedling species in AMF occurrence or colonization was not associated with differences in seed mass among species, variation in seedling size and putative age within a species, or lack of AMF inoculum in the soil. Comparisons of four seedling species growing both in the shaded understory and in small canopy gaps revealed an increase in AMF colonization in two of the four species in gaps, suggesting that light limitation partially explains the low occurrence of AMF. Seedling survival was significantly positively associated with seed biomass but not with AMF colonization. Furthermore, seedling species that regularly formed AMF and those that did not had similar rates of growth and survival, suggesting that mycorrhizal and nonmycorrhizal strategies were equivalent in these forests. Furthermore, the high numbers of seedlings that lacked AMF and the overall low rate of seedling growth (the average seedling required 6 years to double its height) suggest that most seedlings did not receive significant indirect benefits from AMF through connection to canopy trees via a common mycorrhizal network.

Spatial and temporal variation in soil CO2 efflux in an old-growth neotropical rain forest, LA Selva, Costa Rica

Treesearch

Luitgard Schwendenmann; Edzo Veldkamp; Tania Brenes; Joseph J. O' Brien; Jens Mackensen

2003-01-01

Our objectives were to quantify and compare soil CO2, efflux of two doininant soil types in an old-growth neotropical rain forest in the Atlantic zone of Costa Rica, and to evaluate the control of environmental Factors on CO2, release. We measured soil CO2 efflux from eight permanent soil chamhers on...

Bananas and Balsa, Quetzals and Quinine: A Rainforest Unit for Science and Language Arts.

ERIC Educational Resources Information Center

Pottle, Jean L.

The destruction of rain forests and the impact this has on the earth is an important environmental issue. This book was written to help students learn why it is important to protect those areas of the world. In this activity book, students are introduced to a number of inhabitants of the rain forest. They learn about the diversity of plants and…

Throughfall in a Puerto Rican lower montane rain forest: A comparison of sampling strategies

Treesearch

F. Holwerda; F.N. Scatena; L.A. Bruijnzeel

2006-01-01

During a one-year period, the variability of throughfall and the standard errors of the means associated with different gauge arrangements were studied in a lower montane rain forest in Puerto Rico. The following gauge arrangements were used: (1) 60 fixed gauges, (2) 30 fixed gauges, and (3) 30 roving gauges. Stemflow was measured on 22 trees of four different species...

Can salvage logging affect seed dispersal by birds into burned forests?

NASA Astrophysics Data System (ADS)

Rost, J.; Pons, P.; Bas, J. M.

2009-09-01

The recovery of vegetation in Mediterranean ecosystems after wildfire is mostly a result of direct regeneration, since the same species existing before the fire regenerate on-site by seeding or resprouting. However, the possibility of plant colonization by dispersal of seeds from unburned areas remains poorly studied. We addressed the role of the frugivorous, bird-dependent seed dispersal (seed rain) of fleshy-fruited plants in a burned and managed forest in the second winter after a fire, before on-site fruit production had begun. We also assessed the effect on seed rain of different microhabitats resulting from salvage logging (erosion barriers, standing snags, open areas), as well as the microhabitats of unlogged patches and an unburned control forest, taking account of the importance of perches as seed rain sites. We found considerable seed rain by birds in the burned area. Seeds, mostly from Olive trees Olea europaea and Evergreen pistaches Pistacia lentiscus, belonged to plants fruiting only in surrounding unburned areas. Seed rain was heterogeneous, and depended on microhabitat, with the highest seed density in the unburned control forest but closely followed by the wood piles of erosion barriers. In contrast, very low densities were found under perches of standing snags. Furthermore, frugivorous bird richness seemed to be higher in the erosion barriers than elsewhere. Our results highlight the importance of this specific post-fire management in bird-dependent seed rain and also may suggest a consequent heterogeneous distribution of fleshy-fruited plants in burned and managed areas. However, there needs to be more study of the establishment success of dispersed seeds before an accurate assessment can be made of the role of bird-mediated seed dispersal in post-fire regeneration.

Biomass burning in the Amazon-fertilizer for the mountaineous rain forest in Ecuador.

PubMed

Fabian, Peter; Kohlpaintner, Michael; Rollenbeck, Ruetger

2005-09-01

Biomass burning is a source of carbon, sulfur and nitrogen compounds which, along with their photochemically generated reaction products, can be transported over very long distances, even traversing oceans. Chemical analyses of rain and fogwater samples collected in the mountaineous rain forest of south Ecuador show frequent episodes of high sulfate and nitrate concentration, from which annual deposition rates are derived comparable to those found in polluted central Europe. As significant anthropogenic sources are lacking at the research site it is suspected that biomass burning upwind in the Amazon basin is the major source of the enhanced sulfate and nitrate imput. Regular rain and fogwater sampling along an altitude profile between 1800 and 3185 m has been carried out in the Podocarpus National Park close to the Rio SanFrancisco (3 degrees 58'S, 79 degrees 5'W) in southern Ecuador. pH values, electrical conductivity and chemical ion composition were measured at the TUM-WZW using standard methods. Results reported cover over one year from March 2002 until May 2003. Annual deposition rates of sulfate were calculated ranging between 4 and 13 kg S/ha year, almost as high as in polluted central Europe. Nitrogen deposition via ammonia (1.5-4.4 kg N/ha year) and nitrate (0.5-0.8 kg N/ha year) was found to be lower but still much higher than to be expected in such pristine natural forest environment. By means of back trajectory analyses it can be shown that most of the enhanced sulfur and nitrogen deposition is most likely due to forest fires far upwind of the ecuadorian sampling site, showing a seasonal variation, with sources predominantly found in the East/North East during January-March (Colombia, Venezuala, Northern Brazil) and East/SouthEast during July-September (Peru, Brazil). Our results show that biomass burning in the Amazon basin is the predominant source of sulfur and nitrogen compounds that fertilize the mountaineous rain forest in south Ecuador. The mountaineous rain forest in south Ecuador has developed on poor and acid soils, with low nutrient availability. The additional ferilization resulting from anthropogenic biomass burning constitutes a significant disturbance of this ecosystem, its functioning and biodiversity. Thus it is planned to employ isotope analyses for quantifying the pathways. of nitrate and sulfate deposition in these natural forests.

Scientific approach as an understanding and applications of hydrological concepts of tropical rainforest

NASA Astrophysics Data System (ADS)

Haryanto, Z.; Setyasih, I.

2018-04-01

East Kalimantan has a variety of biomes, one of which is tropical rain forests. Tropical rain forests have enormous hydrological potential, so it is necessary to provide understanding to prospective teachers. Hydrology material cannot be separated from the concept of science, for it is needed the right way of learning so students easily understand the material. This research uses descriptive method with research subject is geography education students taking hydrology course at Faculty of Teacher Training and Education, Mulawarman University. The results showed that the students were able to observe, ask question, collect data, give reason, and communicate the hydrological conditions of tropical rain forest biomes, especially related to surface ground water and groundwater conditions. Tropical rainforests are very influenced by the hydrological conditions of the region and the availability of water is affected by the forest area as a catchment area. Therefore, the tropical rainforest must be maintained in condition and its duration, so that there is no water crisis and hydrological related disasters.

Contributions of acid rain research to the forest science-policy interface: learning from the national acid precipitation assessment program.

Treesearch

Charles E. Peterson; David S. Shriner

2004-01-01

During the 1970s, there was growing concern by scientists, policy officials and the general public in the USA over the possible effects of acid rain on human health and the environment (crops, forests, water, etc.). The lack of science-based information needed for policy and regulatory decisions led Congress to create an interagency task force in 1980 called the...

Valuing a Global Environmental Good: U.S. Residents' Willingness to Pay to Protect Tropical Rain Forests

Treesearch

Randall A. Kramer; D. Evan Mercer

1997-01-01

(CV) is the most common technique for valuing nonmarket environmental resources, rarely has it been applied to global environmental goods. This study uses CV in a national survey to assess the value U.S. residents place on tropical rain forest protection. On average, respondents were willing to make a one-time payment of approximately $21-31 per household to protect an...

Vulnerability to xylem embolism as a major correlate of the environmental distribution of rain forest species on a tropical island.

PubMed

Trueba, Santiago; Pouteau, Robin; Lens, Frederic; Feild, Taylor S; Isnard, Sandrine; Olson, Mark E; Delzon, Sylvain

2017-02-01

Increases in drought-induced tree mortality are being observed in tropical rain forests worldwide and are also likely to affect the geographical distribution of tropical vegetation. However, the mechanisms underlying the drought vulnerability and environmental distribution of tropical species have been little studied. We measured vulnerability to xylem embolism (P 50 ) of 13 woody species endemic to New Caledonia and with different xylem conduit morphologies. We examined the relation between P 50 , along with other leaf and xylem functional traits, and a range of habitat variables. Selected species had P 50 values ranging between -4.03 and -2.00 MPa with most species falling in a narrow range of resistance to embolism above -2.7 MPa. Embolism vulnerability was significantly correlated with elevation, mean annual temperature and percentage of species occurrences located in rain forest habitats. Xylem conduit type did not explain variation in P 50 . Commonly used functional traits such as wood density and leaf traits were not related to embolism vulnerability. Xylem embolism vulnerability stands out among other commonly used functional traits as a major driver of species environmental distribution. Drought-induced xylem embolism vulnerability behaves as a physiological trait closely associated with the habitat occupation of rain forest woody species. © 2016 John Wiley & Sons Ltd.

Modern pollen-rain characteristics of tall terra firme moist evergreen forest, southern Amazonia

NASA Astrophysics Data System (ADS)

Gosling, William D.; Mayle, Francis E.; Tate, Nicholas J.; Killeen, Timothy J.

2005-11-01

The paucity of modern pollen-rain data from Amazonia constitutes a significant barrier to understanding the Late Quaternary vegetation history of this globally important tropical forest region. Here, we present the first modern pollen-rain data for tall terra firme moist evergreen Amazon forest, collected between 1999 and 2001 from artificial pollen traps within a 500 × 20 m permanent study plot (14°34'50″S, 60°49'48″W) in Noel Kempff Mercado National Park (NE Bolivia). Spearman's rank correlations were performed to assess the extent of spatial and inter-annual variability in the pollen rain, whilst statistically distinctive taxa were identified using Principal Components Analysis (PCA). Comparisons with the floristic and basal area data of the plot (stems ≥10 cm d.b.h.) enabled the degree to which taxa are over/under-represented in the pollen rain to be assessed (using R-rel values). Moraceae/Urticaceae dominates the pollen rain (64% median abundance) and is also an important constituent of the vegetation, accounting for 16% of stems ≥10 cm d.b.h. and ca. 11% of the total basal area. Other important pollen taxa are Arecaceae (cf. Euterpe), Melastomataceae/Combretaceae, Cecropia, Didymopanax, Celtis, and Alchornea. However, 75% of stems and 67% of the total basal area of the plot ≥10 cm d.b.h. belong to species which are unidentified in the pollen rain, the most important of which are Phenakospermum guianensis (a banana-like herb) and the key canopy-emergent trees, Erisma uncinatum and Qualea paraensis.

ACID RAIN AND SOIL MICROBIAL ACTIVITY: EFFECTS AND THEIR MECHANISMS

EPA Science Inventory

In the investigation, our aim was to determine if acid rain affects soil microbial activity and to identify possible mechanisms of observed effects. A Sierran forest soil (pH 6.4) planted with Ponderosa pine seedlings was exposed to simulated rain (pH 2.0, 3.0, 4.0 and 5.6) with ...

A Student Guide to Tropical Forest Conservation

Treesearch

J. Louise Mastrantonio; John K. Francis

1997-01-01

Tropical forests, which circle the globe, are surprisingly diverse, ranging from rain forests to savannas. Tropical forests are disappearing at an alarming rate as they are converted to farmland and other uses. Modern forest management practices can help stem the tide by providing income and valuable products while maintaining forest cover. Puerto Rico has already gone...

Tropical savannas and dry forests.

PubMed

Pennington, R Toby; Lehmann, Caroline E R; Rowland, Lucy M

2018-05-07

In the tropics, research, conservation and public attention focus on rain forests, but this neglects that half of the global tropics have a seasonally dry climate. These regions are home to dry forests and savannas (Figures 1 and 2), and are the focus of this Primer. The attention given to rain forests is understandable. Their high species diversity, sheer stature and luxuriance thrill biologists today as much as they did the first explorers in the Age of Discovery. Although dry forest and savanna may make less of a first impression, they support a fascinating diversity of plant strategies to cope with stress and disturbance including fire, drought and herbivory. Savannas played a fundamental role in human evolution, and across Africa and India they support iconic megafauna. Copyright © 2018 Elsevier Ltd. All rights reserved.

77 FR 48494 - Hiawatha East Resource Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-14

...: Janel Crooks, RAC Coordinator, USDA, Hiawatha National Forest, 820 Rains Drive, Gladstone, Michigan...; attn RAC; 820 Rains Drive, Gladstone, MI 49837, or by email to [email protected] or via facsimile to...

[Species composition and diversity of soil mesofauna in the 'Holy Hills' fragmentary tropical rain forest of Xishuangbanna, China].

PubMed

Yang, X; Sha, L

2001-04-01

The species composition and diversity of soil mesofauna were examined in fragmented dry tropical seasonal rainforest of tow 'Holy Hills' of Dai nationality, compared with the continuous moist tropical seasonal rain forest of Nature Reserve in Xishuangbanna area. 5 sample quadrats were selected along the diagonal of 20 m x 20 m sampling plot, and the samples of litterfall and 0-3 cm soil were collected from each 50 cm x 10 cm sample quadrat. Animals in soil sample were collected by using dry-funnel(Tullgren's), were identified to their groups according to the order. The H' index, D.G index and the pattern of relative abundance of species were used to compare the diversity of soil mesofauna. The results showed that the disturbance of vegetation and soil resulted by tropical rainforest fragmentation was the major factor affecting the diversity of soil mesofauna. Because the fragmented forest was intruded by some pioneer tree species and the "dry and warm" effect operated, this forest had more litterfall on the floor and more humus in the soil than the continuous moist rain forest. The soil condition with more soil organic matter, total N and P, higher pH value and lower soil bulk density became more favorable to the soil mesofauna. Therefore, the species richness, abundance and diversity of soil mesofauna in fragmented forests were higher than those in continuous forest, but the similarity of species composition in fragmented forest to the continuous forest was minimal. Soil mesofauna diversity in fragmented forests did not change with decreasing fragmented area, indicating that there was no species-area effect operation in this forest. The pattern of relative abundance of species in these forest soils was logarithmic series distribution.

Trace gas and aerosol transports into and out of the Amazon Basin

NASA Technical Reports Server (NTRS)

Garstang, Michael; Greco, Steven

1991-01-01

Overviews of the wet season Amazon Boundary Layer Experiment (ABLE IIB) are presented which give the context of the wet season experiment and some of the results. Copies of all reprints and manuscripts published or accepted for publication are attached. A complete list of all papers published in the reviewed literature, papers presented as well as published as part of conference preceedings, and articles published in the news media are listed in the appendices. Two scales of interaction of the rain forest were pursued in this work: (1) global interactions; and (2) local and regional interactions. Under the first scale, the role of the rain forest in the global system was the central thrust of the work. Under the second scale, the role of the rain forest on the basin and smaller scales was emphasized. The appendices also provide a summary of future work and a listing of degrees awarded during this report period.

Convergent structural responses of tropical forests to diverse disturbance regimes.

PubMed

Kellner, James R; Asner, Gregory P

2009-09-01

Size frequency distributions of canopy gaps are a hallmark of forest dynamics. But it remains unknown whether legacies of forest disturbance are influencing vertical size structure of landscapes, or space-filling in the canopy volume. We used data from LiDAR remote sensing to quantify distributions of canopy height and sizes of 434,501 canopy gaps in five tropical rain forest landscapes in Costa Rica and Hawaii. The sites represented a wide range of variation in structure and natural disturbance history, from canopy gap dynamics in lowland Costa Rica and Hawaii, to stages and types of stand-level dieback on upland Mauna Kea and Kohala volcanoes. Large differences in vertical canopy structure characterized these five tropical rain forest landscapes, some of which were related to known disturbance events. Although there were quantitative differences in the values of scaling exponents within and among sites, size frequency distributions of canopy gaps followed power laws at all sites and in all canopy height classes. Scaling relationships in gap size at different heights in the canopy were qualitatively similar at all sites, revealing a remarkable similarity despite clearly defined differences in species composition and modes of prevailing disturbance. These findings indicate that power-law gap-size frequency distributions are ubiquitous features of these five tropical rain forest landscapes, and suggest that mechanisms of forest disturbance may be secondary to other processes in determining vertical and horizontal size structure in canopies.

Long-term measurement of terpenoid flux above a Larix kaempferi forest using a relaxed eddy accumulation method

NASA Astrophysics Data System (ADS)

Mochizuki, Tomoki; Tani, Akira; Takahashi, Yoshiyuki; Saigusa, Nobuko; Ueyama, Masahito

2014-02-01

Terpenoids emitted from forests contribute to the formation of secondary organic aerosols and affect the carbon budgets of forest ecosystems. To investigate seasonal variation in terpenoid flux involved in the aerosol formation and carbon budget, we measured the terpenoid flux of a Larix kaempferi forest between May 2011 and May 2012 by using a relaxed eddy accumulation method. Isoprene was emitted from a fern plant species Dryopteris crassirhizoma on the forest floor and monoterpenes from the L. kaempferi. α-Pinene was the dominant compound, but seasonal variation of the monoterpene composition was observed. High isoprene and monoterpene fluxes were observed in July and August. The total monoterpene flux was dependent on temperature, but several unusual high positive fluxes were observed after rain fall events. We found a good correlation between total monoterpene flux and volumetric soil water content (r = 0.88), and used this correlation to estimate monoterpene flux after rain events and calculate annual terpenoid emissions. Annual carbon emission in the form of total monoterpenes plus isoprene was determined to be 0.93% of the net ecosystem exchange. If we do not consider the effect of rain fall, carbon emissions may be underestimated by about 50%. Our results suggest that moisture conditions in the forest soil is a key factor controlling the monoterpene emissions from the forest ecosystem.

Spatial contagiousness of canopy disturbance in tropical rain forest: an individual-tree-based test.

PubMed

Jansen, Patrick A; van der Meer, Peter J; Bongers, Frans

2008-12-01

Spatial contagiousness of canopy dynamics-the tendency of canopy disturbances to occur nearby existing canopy openings due to an elevated risk of tree fall around gaps-has been demonstrated in many temperate-zone forests, but only inferentially for tropical forests. Hypothesized mechanisms increasing the risk of tree fall around tropical forest gaps are (1) increased tree exposure to wind around gaps, (2) reduced stability of trees alongside gaps due to crown asymmetry, or (3) reduced tree health around gaps due to damage from prior disturbances. One hypothesized consequence of elevated disturbance levels around gaps would be that gap-edge zones offer relatively favorable prospects for seedling recruitment, growth, and survival. We tested whether disturbance levels are indeed elevated around natural canopy gaps in a neotropical rain forest in French Guiana, and more so as gaps are larger. We followed the fate of 5660 trees >10 cm stem diameter over five years across 12 ha of old-growth forest and analyzed the risk and magnitude of canopy disturbance events in relation to tree diameter and the proximity and size of natural canopy gaps. We found that the cumulative incidence of disturbance over the five-year survey was not significantly elevated around preexisting gaps, and only weakly related to gap size. Also, neither the risk nor the magnitude of canopy disturbances increased significantly with the proximity of gaps. Moreover, canopy disturbance risk around gaps was independent of gap size, while the magnitude of disturbance events around gaps was weakly related to gap size. Tree size was the major driver of disturbance risk as well as magnitude. We did find an elevated incidence of disturbance inside preexisting gaps, but this "repeat disturbance" was due to an elevated disturbance risk inside gaps, not around gaps. Overall, we found no strong evidence for canopy dynamics in this rain forest being spatially contagious. Our findings are consistent with the traditional view of tropical rain forests as mosaics of patches with predictable regeneration cycles.

Colossal carbon! Disturbance and biomass dynamics in Alaska's national forests

Treesearch

John Kirkland; Tara Barrett

2016-01-01

The Chugach and Tongass National Forests are changing, possibly in response to global warming. Forested areas within Alaska's temperate rain forests are creeping into areas that were previously too cold or too wet. These forests are also becoming denser. As biomass increases, the amount of carbon stored in the forest also increases. Tara Barrett, a...

An Overview.

ERIC Educational Resources Information Center

NatureScope, 1989

1989-01-01

Focuses on the characteristics of tropical rain forests, where they grow, and some of the misconceptions about them. Includes six activities on: figuring out forests, jungle journey, tropical trivia trek, forest comparisons, and lost in the jungle. Five copyable sheets are provided. (RT)

Guatemalan forest synthesis after Pleistocene aridity

PubMed Central

Leyden, Barbara W.

1984-01-01

Sediments from two lakes in the Peten Department, Guatemala, provide palynological evidence from Central America of late Pleistocene aridity and subsequent synthesis of mesic forests. Late Glacial vegetation consisted of marsh, savanna, and juniper scrub. An early Holocene temperate forest preceded a mesic tropical forest with Brosimum (ramon). Thus “primeval” rain forests of Guatemala are no older than 10,000 to 11,000 years and are considerably younger in the Peten due to Mayan disturbances. Among dated Neotropical sites, the Peten has the most mesic vegetation yet shown to have supplanted xeric vegetation present during the Pleistocene. The arid late Glacial-humid early Holocene transition appears to have been pantropical in the lowlands. The Peten was not a Pleistocene refugium for mesophytic taxa, as has been suggested. Thus genesis of extant rain forests in northern Central America and southern Mexico remains unexplained. Images PMID:16593498

[Soil seed bank research in China: present status, progress and challenges].

PubMed

Shen, You-Xin; Zhao, Chun-Yan

2009-02-01

By searching soil seed bank (SSB) papers from http://www.cqvip.com (1989-2006) and Web of Science (1985-2006), the information on SSB density, species richness, and research methods were summarized according to the 29 classified vegetation types in Vegetation of China. In total, the data of 238 sites with 14 vegetation types were collected. The results showed that the research methods adopted by different researchers and the obtained data of SSB density and species richness varied greatly. In related researches, sampling work was mostly conducted in April and October, sampling plot number ranged from 2 to 480, plot area ranged from 78 cm2 to 10,000 cm2, with 10 cm x 10 cm and 20 cm x 20 cm as most common, and total sampling area ranged from 600 cm2 to 500,000 cm2, with the most being 1,000-10,000 cm2. SSB density varied from 8 ind x m(-2) (desert) to 65,355 ind x m(-2) (tropical rain forest), and species richness varied from 1 (secondary bare alkali-saline patch in temperate) to 74 (tropical seasonal rain forest) per site. SSB density and species richness were higher in tropical rain forest and seasonal rain forest than in temperate coniferous forest, and in manmade forest than in agricultural land or barren land. Grassland, desert, and meadow had smaller species richness. In future, the SSB research should be extended both in scope and in deepness, with the focus on the long term research and strategy research of some important ecosystems, and the research should be incorporated into vegetation regeneration and restoration studies. The related methodological research should be also emphasized in the future.

Maybeso Experimental Forest.

Treesearch

Valerie Rapp

2004-01-01

The Maybeso Experimental Forest is in southeast Alaska within the Tongass National Forest, the largest national forest in the United States and home to the Northern Hemi-sphere's largest temperate rain forest. Located about 42 miles west of Ketchikan, Alaska, it is on Prince of Wales Island, the largest island of the Alexander Archipelago and the third largest...

Caribbean dry forest networking: an opportunity for conservation

Treesearch

K. Banda-Rodriguez; J. Weintritt; R.T. Pennington

2016-01-01

Seasonally dry tropical forest is the most threatened tropical forest in the world. Though its overall plant species diversity is lower than in neighboring biomes such as rain forest, species endemism can be high, and its conservation has often been neglected. Caribbean dry forests face diverse threats including tourism, agriculture, and climate change. The Latin...

From the Guiana Highlands to the Brazilian Atlantic Rain Forest: four new species of Selaginella (Selaginellaceae – Lycopodiophyta: S. agioneuma, S. magnafornensis, S. ventricosa, and S. zartmanii)

PubMed Central

López, Christian A.; Sierra, Adriel M.; Ceballos, Jorge

2018-01-01

We describe four new species in the genus Selaginella (i.e., S. agioneuma, S. magnafornensis, S. ventricosa, and S. zartmanii) from Brazil, all presently classified in subg. Stachygynandrum. For each of the new taxa we discuss taxonomic affinities and provide information on habitat, distribution, and conservation status. In addition, line drawings and scanning electron microscope (SEM) images of stems sections, leaves, and spores (when present) are included. Selaginella agioneuma and S. magnafornensis are from the State of Espíritu Santo where they inhabit premontane to montane Atlantic rain forests in the Reserva Biológica Augusto Ruschi and Parque Estadual Forno Grande, respectively. Selaginella ventricosa was collected in upper montane forests at Parque Nacional Serra da Mocidade, State of Roraima and S. zartmanii in premontane Amazon rain forests on upper Rio Negro at Mpio. São Gabriel da Cachoeira, Amazonas State in both Serra Curicuriari and the Morro dos Seis Lagos Biological Reserve. PMID:29770272

Amazon plant diversity revealed by a taxonomically verified species list.

PubMed

Cardoso, Domingos; Särkinen, Tiina; Alexander, Sara; Amorim, André M; Bittrich, Volker; Celis, Marcela; Daly, Douglas C; Fiaschi, Pedro; Funk, Vicki A; Giacomin, Leandro L; Goldenberg, Renato; Heiden, Gustavo; Iganci, João; Kelloff, Carol L; Knapp, Sandra; Cavalcante de Lima, Haroldo; Machado, Anderson F P; Dos Santos, Rubens Manoel; Mello-Silva, Renato; Michelangeli, Fabián A; Mitchell, John; Moonlight, Peter; de Moraes, Pedro Luís Rodrigues; Mori, Scott A; Nunes, Teonildes Sacramento; Pennington, Terry D; Pirani, José Rubens; Prance, Ghillean T; de Queiroz, Luciano Paganucci; Rapini, Alessandro; Riina, Ricarda; Rincon, Carlos Alberto Vargas; Roque, Nádia; Shimizu, Gustavo; Sobral, Marcos; Stehmann, João Renato; Stevens, Warren D; Taylor, Charlotte M; Trovó, Marcelo; van den Berg, Cássio; van der Werff, Henk; Viana, Pedro Lage; Zartman, Charles E; Forzza, Rafaela Campostrini

2017-10-03

Recent debates on the number of plant species in the vast lowland rain forests of the Amazon have been based largely on model estimates, neglecting published checklists based on verified voucher data. Here we collate taxonomically verified checklists to present a list of seed plant species from lowland Amazon rain forests. Our list comprises 14,003 species, of which 6,727 are trees. These figures are similar to estimates derived from nonparametric ecological models, but they contrast strongly with predictions of much higher tree diversity derived from parametric models. Based on the known proportion of tree species in neotropical lowland rain forest communities as measured in complete plot censuses, and on overall estimates of seed plant diversity in Brazil and in the neotropics in general, it is more likely that tree diversity in the Amazon is closer to the lower estimates derived from nonparametric models. Much remains unknown about Amazonian plant diversity, but this taxonomically verified dataset provides a valid starting point for macroecological and evolutionary studies aimed at understanding the origin, evolution, and ecology of the exceptional biodiversity of Amazonian forests.

Atlantic tropical forest mapping in the northern coastal zone of Sao Paulo State, Brazil

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

Simi, R. Jr.; Almeida, S.A.S.; Manso, A.P.

1997-06-01

The northern coastal zone of Sao Paulo State includes the cities of Ubatuba, Caraguatatuba, Sao Sebastiao and Ilha Bela. Large development projects, such as road and highway constructions and joint real estate exploration of susceptible coastal ecosystems have threatened the harmony and ecological stability of these ecosystems. Recently, the Atlantic tropical rain forest has been the most destructed ecosystem in the coastal zone in response to real estate investments in urban areas along the main roads. In the northern coastal zone of Sao Paulo State, 80% of the counties are included in the State Park of Serra do Mar. Asmore » tourism is a strong growing economical activity, as well as coastal production, it should be of interest to create a plan for sustainable development. The objective of this study is to map and characterize land use cover changes with emphasis on the Atlantic tropical rain forest degradation using Landsat TM images. Preliminary results for land use cover changes indicate that the Atlantic tropical rain forest was reduced by 6.1 % during the period of July 1992 and October 1995.« less

Amazon plant diversity revealed by a taxonomically verified species list

PubMed Central

Cardoso, Domingos; Särkinen, Tiina; Alexander, Sara; Amorim, André M.; Bittrich, Volker; Celis, Marcela; Daly, Douglas C.; Fiaschi, Pedro; Funk, Vicki A.; Giacomin, Leandro L.; Heiden, Gustavo; Iganci, João; Kelloff, Carol L.; Knapp, Sandra; Cavalcante de Lima, Haroldo; Machado, Anderson F. P.; dos Santos, Rubens Manoel; Mello-Silva, Renato; Michelangeli, Fabián A.; Mitchell, John; Moonlight, Peter; de Moraes, Pedro Luís Rodrigues; Mori, Scott A.; Nunes, Teonildes Sacramento; Pennington, Terry D.; Pirani, José Rubens; Prance, Ghillean T.; de Queiroz, Luciano Paganucci; Rapini, Alessandro; Rincon, Carlos Alberto Vargas; Roque, Nádia; Shimizu, Gustavo; Sobral, Marcos; Stehmann, João Renato; Stevens, Warren D.; Taylor, Charlotte M.; Trovó, Marcelo; van den Berg, Cássio; van der Werff, Henk; Viana, Pedro Lage; Zartman, Charles E.; Forzza, Rafaela Campostrini

2017-01-01

Recent debates on the number of plant species in the vast lowland rain forests of the Amazon have been based largely on model estimates, neglecting published checklists based on verified voucher data. Here we collate taxonomically verified checklists to present a list of seed plant species from lowland Amazon rain forests. Our list comprises 14,003 species, of which 6,727 are trees. These figures are similar to estimates derived from nonparametric ecological models, but they contrast strongly with predictions of much higher tree diversity derived from parametric models. Based on the known proportion of tree species in neotropical lowland rain forest communities as measured in complete plot censuses, and on overall estimates of seed plant diversity in Brazil and in the neotropics in general, it is more likely that tree diversity in the Amazon is closer to the lower estimates derived from nonparametric models. Much remains unknown about Amazonian plant diversity, but this taxonomically verified dataset provides a valid starting point for macroecological and evolutionary studies aimed at understanding the origin, evolution, and ecology of the exceptional biodiversity of Amazonian forests. PMID:28923966

Analysis of Chromobacterium sp. natural isolates from different Brazilian ecosystems

PubMed Central

Lima-Bittencourt, Cláudia I; Astolfi-Filho, Spartaco; Chartone-Souza, Edmar; Santos, Fabrício R; Nascimento, Andréa MA

2007-01-01

Background Chromobacterium violaceum is a free-living bacterium able to survive under diverse environmental conditions. In this study we evaluate the genetic and physiological diversity of Chromobacterium sp. isolates from three Brazilian ecosystems: Brazilian Savannah (Cerrado), Atlantic Rain Forest and Amazon Rain Forest. We have analyzed the diversity with molecular approaches (16S rRNA gene sequences and amplified ribosomal DNA restriction analysis) and phenotypic surveys of antibiotic resistance and biochemistry profiles. Results In general, the clusters based on physiological profiles included isolates from two or more geographical locations indicating that they are not restricted to a single ecosystem. The isolates from Brazilian Savannah presented greater physiologic diversity and their biochemical profile was the most variable of all groupings. The isolates recovered from Amazon and Atlantic Rain Forests presented the most similar biochemical characteristics to the Chromobacterium violaceum ATCC 12472 strain. Clusters based on biochemical profiles were congruent with clusters obtained by the 16S rRNA gene tree. According to the phylogenetic analyses, isolates from the Amazon Rain Forest and Savannah displayed a closer relationship to the Chromobacterium violaceum ATCC 12472. Furthermore, 16S rRNA gene tree revealed a good correlation between phylogenetic clustering and geographic origin. Conclusion The physiological analyses clearly demonstrate the high biochemical versatility found in the C. violaceum genome and molecular methods allowed to detect the intra and inter-population diversity of isolates from three Brazilian ecosystems. PMID:17584942

Building a Global Network of Hydro-climatology Sites in Cloud-affected Tropical Montane Forests

NASA Astrophysics Data System (ADS)

Moore, G. W.; Asbjornsen, H.; Bruijnzeel, S., Sr.; Berry, Z. C.; Giambelluca, T. W.; Martin, P.; Mulligan, M.

2015-12-01

Tropical montane forests are characteristically wet environments with low evapotranspiration and sometimes significant contributions from fog interception. They are often located at headwater catchments critical for water supplies, but ecohydroclimate data in these regions are sparse. Such evidence may be crucial for assessing climate alterations in these sensitive ecosystems. As part of a global effort led by the Tropical Montane Cloud Forest Research Coordination Network (Cloudnet - http://cloudnet.agsci.colostate.edu), we aim to extend the network of tropical montane forest sites and establish robust protocols for measuring key ecohydroclimatic parameters, including fog interception, windblown rain, throughfall, leaf wetness, and micrometeorological conditions. Specific recommendations for standardized protocols include (1) rain and fog collectors uniquely designed to separately quantify fog interception from direct rain inputs, even in windy conditions, (2) trough-style throughfall gages that collect 40 times the area of a typical tipping bucket gage with added features to reduce splash-out, (3) clusters of leaf wetness sensors to differentiate frequency and duration of wetness caused by rain and fog on windward and leeward exposures, and (4) basic micrometeorological sensors for solar radiation, temperature, humidity, and wind. At sites where resources allow for additional measurements, we developed protocols for quantifying soil moisture, soil saturation, and plant water uptake from both roots and leaves (i.e. foliar absorption), since these are also important drivers in these systems. Participating sites will be invited to contribute to a global meta-analysis that will provide new insights into the ecohydrology of cloud-affected tropical montane forests.

Effects of coffee management on deforestation rates and forest integrity.

PubMed

Hylander, Kristoffer; Nemomissa, Sileshi; Delrue, Josefien; Enkosa, Woldeyohannes

2013-10-01

Knowledge about how forest margins are utilized can be crucial for a general understanding of changes in forest cover, forest structure, and biodiversity across landscapes. We studied forest-agriculture transitions in southwestern Ethiopia and hypothesized that the presence of coffee (Coffea arabica)decreases deforestation rates because of coffee's importance to local economies and its widespread occurrence in forests and forest margins. Using satellite images and elevation data, we compared changes in forest cover over 37 years (1973-2010) across elevations in 2 forest-agriculture mosaic landscapes (1100 km(2) around Bonga and 3000 km(2) in Goma-Gera). In the field in the Bonga area, we determined coffee cover and forest structure in 40 forest margins that differed in time since deforestation. Both the absolute and relative deforestation rates were lower at coffee-growing elevations compared with at higher elevations (-10/20% vs. -40/50% comparing relative rates at 1800 m asl and 2300-2500 m asl, respectively). Within the coffee-growing elevation, the proportion of sites with high coffee cover (>20%) was significantly higher in stable margins (42% of sites that had been in the same location for the entire period) than in recently changed margins (0% of sites where expansion of annual crops had changed the margin). Disturbance level and forest structure did not differ between sites with 30% or 3% coffee. However, a growing body of literature on gradients of coffee management in Ethiopia reports coffee's negative effects on abundances of forest-specialist species. Even if the presence of coffee slows down the conversion of forest to annual-crop agriculture, there is a risk that an intensification of coffee management will still threaten forest biodiversity, including the genetic diversity of wild coffee. Conservation policy for Ethiopian forests thus needs to develop strategies that acknowledge that forests without coffee production may have higher deforestation risks than forests with coffee production and that forests with coffee production often have lower biodiversity value. © 2013 Society for Conservation Biology.

Estimation of the rain signal in the presence of large surface clutter

NASA Technical Reports Server (NTRS)

Ahamad, Atiq; Moore, Richard K.

1994-01-01

The principal limitation for the use of a spaceborne imaging SAR as a rain radar is the surface-clutter problem. Signals may be estimated in the presence of noise by averaging large numbers of independent samples. This method was applied to obtain an estimate of the rain echo by averaging a set of N(sub c) samples of the clutter in a separate measurement and subtracting the clutter estimate from the combined estimate. The number of samples required for successful estimation (within 10-20%) for off-vertical angles of incidence appears to be prohibitively large. However, by appropriately degrading the resolution in both range and azimuth, the required number of samples can be obtained. For vertical incidence, the number of samples required for successful estimation is reasonable. In estimating the clutter it was assumed that the surface echo is the same outside the rain volume as it is within the rain volume. This may be true for the forest echo, but for convective storms over the ocean the surface echo outside the rain volume is very different from that within. It is suggested that the experiment be performed with vertical incidence over forest to overcome this limitation.

The role of urban forest to reduce rain acid in urban industrial areas

NASA Astrophysics Data System (ADS)

Slamet, B.; Agustiarni, Y.; Hidayati; Basyuni, M.

2018-03-01

Urban forest has many functions mainly on improving the quality of the urban environment. One of the functions is to increase pH and reduce dangerous chemical content. The aim of the research is to find out the role of vegetation density of urban forest around the industrial area in reducing the acid rain. The condition of land cover was classified into four classes which are dense, medium, sparse and open area. The water of the throughfall and stemflow was taken from each type of land cover except in the open area. Parameters measured in this study are water acidity (pH), anion content (SO4 2- and NO3 -), cation content (Ca2+, Mg2+, and NH4 +) and electrical conductivity (EC). The results indicated that urban forest vegetation was able to increase the pH of rain water from 5.42 which is in an open area without vegetation to be 7.13 and 7.32 in dense and moderate vegetation cover by throughfall mechanism, respectively. Rain water acidity also decreased through stemflow mechanism with a pH ranged from 5.92 - 6.43. Urban forest vegetation decreased sulfate content (SO42-) from 528.67 mg/l in open area to 44 - 118 mg/l by throughfall mechanism and ranged from 90 to 366.67 mg/l through stemflow mechanism. Urban forest vegetation significantly decreased the rainwater nitrate content from 27 mg/l to 0.03 - 0.70 mg/l through the mechanism of throughfall and between 1.53 - 8.82 mg/l through the stemflow mechanism. Urban forest vegetation also increased the concentration of cations (NH4+, Ca2+, Mg2+, Na+) compared with open areas. Urban forest vegetation showed increased the electrical conductivity (EC) from 208.12 μmhos/cm to 344.67 - 902.17 μmhos/cm through the through fall mechanism and 937.67 - 1058.70 μmhos/cm through the stemflow mechanism. The study suggested that urban forests play a significant role in reducing rainwater acidity and improving the quality of rainwater that reached the soil surface.

The impacts of selective logging and clear-cutting on woody plant diversity after 40years of natural recovery in a tropical montane rain forest, south China.

PubMed

Ding, Yi; Zang, Runguo; Lu, Xinghui; Huang, Jihong

2017-02-01

Historically, clear-cutting and selective logging have been the commercial logging practices. However, the effect of these pervasive timber extraction methods on biodiversity in tropical forests is still poorly understood. In this study, we compared abiotic factors, species diversity, community composition, and structure between ca. 40-year-old clear-cut (MCC); ca. 40-year-old selectively logged (MSL); and tropical old growth montane rain forests (MOG) on Hainan Island, China. Results showed that there were a large number of trees with a diameter at breast height (DBH) <30cm in the two logged forests. Additionally, the two logged forests only had 40% of the basal area of the large trees (DBH≥30cm) found in the old growth forest. The species richness and Shannon-Wiener diversity indices generally showed no difference among the three forest types. MCC had 70% of the species richness of the large trees in the MOG, whereas MSL and MOG had similar species richness. High value timber species had similar species richness among the three forest types, but a lower abundance and basal area of large trees in MCC. The species composition was distinct between the three forests. Large trees belonging to the family Fagaceae dominated in the logged forests and played a more important role in the old growth forest. Huge trees (DBH≥70cm) were rare in MCC, but were frequently found in MSL. Most abiotic factors varied inconsistently among the three forest types and few variables related to species diversity, community structure and composition. Our study indicated that MSL had a relatively faster recovery rate than MCC in a tropical montane rain forest after 40years, but both logged forests had a high recovery potential over a long-term. Copyright © 2016 Elsevier B.V. All rights reserved.

Peak discharges in steep mountain catchments in relation to rainfall variability, vegetation cover and geomorphology of the Rift Valley Escarpment of Northern Ethiopia

NASA Astrophysics Data System (ADS)

Gebreyohannes, Tesfaalem; Frankl, Amaury; Haile, Mitiku; Abraha, Amanuel; Monsieurs, Elise; Nyssen, Jan

2015-04-01

The hydrological characteristics of steep mountain streams are often considered to be mainly influenced by rainfall distribution and topography. In this study, with the objective of analyzing the runoff response of mountain catchments, a total of 340 peak stage discharges were recorded in three rainy seasons (2012-2014) in 11 sloping (27-65%) mountain catchments (0.4 - 25 km²) of the marginal western Rift Valley escarpment of Northern Ethiopia. Daily rainfall data were collected using 7 rain gauges installed at different altitudes (1623 - 2851 m a.s.l) in and nearby the catchments, and used to calculate weighted average daily rain depths over the catchments. Event peak discharges were calculated from daily measurements by 11 crest stage gauges using the Manning's equation. Percentages of land use and cover classes were detected from high resolution (0.6 m) Google Earth imagery (February 1, 2014). Morphometric characteristics of the catchments were computed from ASTER digital elevation model and topographic maps. Correlation analysis between daily rainfall and peak discharge showed direct relationship (R² = 0.5-0.94, P<0.01) in all the catchments. The average specific peak discharge was negatively related to percentage of forest and grass cover (R² = 0.64, P<0.01), time of concentration (R² = 0.31, P<0.01), drainage texture (R² = 0.42, P<0.01), and catchment perimeter (R² = 0.36, P<0.01). The specific peak discharge was positively correlated with average slope gradient of the catchments (R² = 0.34, P<0.01) and with an index representing the spatial distribution of forest and grass cover (R² = 0.43, P<0.01). A stepwise multiple regression analyses showed that 84% (P<0.01) of the variability of the runoff response in the catchments can be predicted by the percentage of forest and grass cover and the relief ratio of the catchments. All in all, this study demonstrates that the magnitude of flash floods in mountain catchments is not only influenced by the morphometric characteristics of the catchments and by rainfall, but more importantly even by vegetation cover (forest and grasses).

Short-Term Exposure to Warm Microhabitats Could Explain Amphibian Persistence with Batrachochytrium dendrobatidis

PubMed Central

Daskin, Joshua H.; Alford, Ross A.; Puschendorf, Robert

2011-01-01

Environmental conditions can alter the outcomes of symbiotic interactions. Many amphibian species have declined due to chytridiomycosis, caused by the pathogenic fungus Batrachochytrium dendrobatidis (Bd), but many others persist despite high Bd infection prevalence. This indicates that Bd's virulence is lower, or it may even be a commensal, in some hosts. In the Australian Wet Tropics, chytridiomycosis extirpated Litoria nannotis from high-elevation rain forests in the early 1990 s. Although the species is recolonizing many sites, no population has fully recovered. Litoria lorica disappeared from all known sites in the early 1990 s and was thought globally extinct, but a new population was discovered in 2008, in an upland dry forest habitat it shares with L. nannotis. All frogs of both species observed during three population censuses were apparently healthy, but most carried Bd. Frogs perch on sun-warmed rocks in dry forest streams, possibly keeping Bd infections below the lethal threshold attained in cooler rain forests. We tested whether short-term elevated temperatures can hamper Bd growth in vitro over one generation (four days). Simulating the temperatures available to frogs on strongly and moderately warmed rocks in dry forests, by incubating cultures at 33°C for one hour daily, reduced Bd growth below that of Bd held at 15°C constantly (representing rain forest habitats). Even small decreases in the exponential growth rate of Bd on hosts may contribute to the survival of frogs in dry forests. PMID:22028834

Short-term exposure to warm microhabitats could explain amphibian persistence with Batrachochytrium dendrobatidis.

PubMed

Daskin, Joshua H; Alford, Ross A; Puschendorf, Robert

2011-01-01

Environmental conditions can alter the outcomes of symbiotic interactions. Many amphibian species have declined due to chytridiomycosis, caused by the pathogenic fungus Batrachochytrium dendrobatidis (Bd), but many others persist despite high Bd infection prevalence. This indicates that Bd's virulence is lower, or it may even be a commensal, in some hosts. In the Australian Wet Tropics, chytridiomycosis extirpated Litoria nannotis from high-elevation rain forests in the early 1990 s. Although the species is recolonizing many sites, no population has fully recovered. Litoria lorica disappeared from all known sites in the early 1990 s and was thought globally extinct, but a new population was discovered in 2008, in an upland dry forest habitat it shares with L. nannotis. All frogs of both species observed during three population censuses were apparently healthy, but most carried Bd. Frogs perch on sun-warmed rocks in dry forest streams, possibly keeping Bd infections below the lethal threshold attained in cooler rain forests. We tested whether short-term elevated temperatures can hamper Bd growth in vitro over one generation (four days). Simulating the temperatures available to frogs on strongly and moderately warmed rocks in dry forests, by incubating cultures at 33°C for one hour daily, reduced Bd growth below that of Bd held at 15°C constantly (representing rain forest habitats). Even small decreases in the exponential growth rate of Bd on hosts may contribute to the survival of frogs in dry forests.

Applications of a hand-held GPS receiver in South American rain forests

NASA Technical Reports Server (NTRS)

Baksh, Michael

1991-01-01

A hand-held Global Positioning System receiver was used to determine the precise locations of villages, houses, gardens, and other cultural and environmental features in poorly mapped South American rain forests. The Magellan NAV 1000 unit profides extremely accurate latitude and longitude information, but determination of altitude is problematical. Overall, the receiver effectively allows anthropologists to obtain essential locational data useful for categorizing land uses, mapping tribal boundaries, and other applications in regions where environmental conditions are harsh and/or accessibility is difficult.

The biogeographic origin of a radiation of trees in Madagascar: implications for the assembly of a tropical forest biome.

PubMed

Federman, Sarah; Dornburg, Alex; Downie, Alexander; Richard, Alison F; Daly, Douglas C; Donoghue, Michael J

2015-10-05

Madagascar's rain forests are characterized by extreme and uneven patterns of species richness and endemicity, the biogeographic and evolutionary origins of which are poorly understood. Here we use a time-calibrated phylogeny of a dominant group of trees in Madagascar's eastern rain forests, Canarium, and related Burseraceae (Canarieae), to test biogeographic hypotheses regarding the origin and radiation of the flora of this unique biome. Our findings strongly support the monophyly of Malagasy Canarium, suggesting that this clade represents a previously undocumented in situ radiation. Contrary to expectations of dispersal from Africa during the Oligocene, concurrent with the formation of Madagascar's rain forest biome, our analyses support a late Miocene origin for Malagasy Canarium, probably by long distance dispersal from Southeast Asia. Our study illustrates the importance of considering long distance dispersal as a viable explanation for clades with pantropical distributions diversifying subsequent to the Oligocene, and it highlights the formation of the Indo-Australian Archipelago and associated fast-moving equatorial surface currents, suggesting an under-appreciated evolutionary link among tropical centers of endemism. We postulate that the relatively recent establishment and radiation of Canarium in Madagascar may have been facilitated by the highly stochastic climates associated with these forest ecosystems.

The contrasting nature of woody plant species in different neotropical forest biomes reflects differences in ecological stability.

PubMed

Pennington, R Toby; Lavin, Matt

2016-04-01

A fundamental premise of this review is that distinctive phylogenetic and biogeographic patterns in clades endemic to different major biomes illuminate the evolutionary process. In seasonally dry tropical forests (SDTFs), phylogenies are geographically structured and multiple individuals representing single species coalesce. This pattern of monophyletic species, coupled with their old species stem ages, is indicative of maintenance of small effective population sizes over evolutionary timescales, which suggests that SDTF is difficult to immigrate into because of persistent resident lineages adapted to a stable, seasonally dry ecology. By contrast, lack of coalescence in conspecific accessions of abundant and often widespread species is more frequent in rain forests and is likely to reflect large effective population sizes maintained over huge areas by effective seed and pollen flow. Species nonmonophyly, young species stem ages and lack of geographical structure in rain forest phylogenies may reflect more widespread disturbance by drought and landscape evolution causing resident mortality that opens up greater opportunities for immigration and speciation. We recommend full species sampling and inclusion of multiple accessions representing individual species in phylogenies to highlight nonmonophyletic species, which we predict will be frequent in rain forest and savanna, and which represent excellent case studies of incipient speciation. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

Diversity and aboveground biomass of lianas in the tropical seasonal rain forests of Xishuangbanna, SW China.

PubMed

Lü, Xiao-Tao; Tang, Jian-Wei; Feng, Zhi-Li; Li, Mai-He

2009-01-01

Lianas are important components of tropical forests and have significant impacts on the diversity, structure and dynamics of tropical forests. The present study documented the liana flora in a Chinese tropical region. Species richness, abundance, size-class distribution and spatial patterns of lianas were investigated in three 1-ha plots in tropical seasonal rain forests in Xishuangbanna, SW China. All lianas with > or = 2 cm diameter at breast height (dbh) were measured, tagged and identified. A total of 458 liana stems belonging to 95 species (ranging from 38 to 50 species/ha), 59 genera and 32 families were recorded in the three plots. The most well-represented families were Loganiaceae, Annonceae, Papilionaceae, Apocynaceae and Rhamnaceae. Papilionaceae (14 species recorded) was the most important family in the study forests. The population density, basal area and importance value index (IVI) varied greatly across the three plots. Strychnos cathayensis, Byttneria grandifolia and Bousigonia mekongensis were the dominant species in terms of IVI across the three plots. The mean aboveground biomass of lianas (3 396 kg/ha) accounted for 1.4% of the total community above-ground biomass. The abundance, diversity and biomass of lianas in Xishuangbanna tropical seasonal rain forests are lower than those in tropical moist and wet forests, but higher than those in tropical dry forests. This study provides new data on lianas from a geographical region that has been little-studied. Our findings emphasize that other factors beyond the amount and seasonality of precipitation should be included when considering the liana abundance patterns across scales.

The characteristics of soil and water loss in Pinus Massoniana forest in Quaternary red soil area of south China

NASA Astrophysics Data System (ADS)

Song, Yuejun; Huang, Yanhe; Jie, Yang

2017-08-01

The soil and water loss in Pinus massoniana forests is an urgent environmental problem in the red soil region of southern China.Using the method of field monitoring, by analogy and statistical analysis, The characteristics of soil and water loss of Pinus massoniana forests in Quaternary red soil region under 30 rainfall were analyzed,the results show that the relationship models of rainfall,runoff and sediment of pure Pinus massoniana plot were slightly different from the naked control plot,were all the univariate quadratic linear regression models.the contribution of runoff and sediment in different rain types were different, and the water and soil loss in Pinus massoniana forest was most prominent under moderate rain.The merging effect of sparse Pinus massoniana forest on raindrop, aggravated the degree of soil and water loss to some extent.

Evaluation of the use of scientific information in developing the 1997 Forest plan for the Tongass National Forest.

Treesearch

Fred H. Everest; Douglas N. Swanston; Charles G. Shaw; Winston P. Smith; Kent R. Julin; Stewart D. Allen

1997-01-01

The Tongass National Forest is the largest remaining relatively unaltered coastal temperate rain forest in the world. The Forest consists of 16.9 million acres of land distributed across more that 22,000 islands and a narrow strip of mainland in southeast Alaska. The Forest contains abundant timber, wildlife, fisheries, mineral, and scenic resources. The authors...

Forest biological diversity interactions with resource utilization

Treesearch

S.T. Mok

1992-01-01

The most important forest resources of the Asia-Pacific region are the highly diverse rain forests. Utilization of the resource is a natural and inevitable consequence of the region's socio-economic development. The sustainable management and development of forest resources in the region can be achieved by implementing conservational forestry, which is based on...

Restoration of Native Hawaiian Dryland Forest at Auwahi, Maui

USGS Publications Warehouse

Medieros, Arthur C.; vonAllmen, Erica

2006-01-01

BACKGROUND The powerful volcanoes that formed the high islands of the Hawaiian archipelago block northeasterly tradewinds, creating wet, windward rain forests and much drier, leeward forests. Dryland forests in Hawai'i receive only about 20 inches of rain a year. However, the trees in these forests intercept fog and increase ground moisture levels, thereby enabling these seemingly inhospitable habitats to support a diverse assemblage of plants and animals. Dryland forests of the Hawaiian Islands, like those worldwide, have been heavily impacted by humans both directly and indirectly. Less than 10% of Hawai'i's original dryland forest habitat remains. These forests have been severely impacted by urban development, ranching and agriculture, and invasive species. In particular, browsing animals and alien grasses have caused significant damage. Feral ungulates, including goats, sheep, cattle, and pigs, consume sensitive plants. Alien grasses have become dominant in the understory in many dryland habitats. In addition, these introduced grasses are fire-adapted and have increased the incidence of wildfire in these ecosystems. Native Hawaiian plants did not evolve with frequent fires or mammalian herbivores and typically do not survive well under these pressures.

Off-nadir antenna bias correction using Amazon rain forest sigma deg data. [Brazil

NASA Technical Reports Server (NTRS)

Birrer, I. J.; Bracalente, E. M.; Dome, G. J.; Sweet, J.; Berthold, G.; Moore, R. K. (Principal Investigator)

1981-01-01

The radar response from the Amazon rain forest was studied to determine the suitability of this region for use as a standard target to calibrate a scatterometer like that proposed for the National Ocean Satellite System (NOSS). Backscattering observations made by the SEASAT-1 scatterometer system show the Amazon rain forest to be a homogeneous, azimuthally-isotropic, radar target which is insensitive to polarization. The variation with angle of incidence may be adequately modeled as sigma deg (dB) = alpha theta + beta with typical values for the incidence-angle coefficient from 0.07 dB deg to 0.15 dB/deg. A small diurnal effect occurs, with measurements at sunrise being 0.5 dB to 1 dB higher than the rest of the day. Maximum likelihood estimation algorithms are presented which permit determination of relative bias and true pointing angle for each beam. Specific implementation of these algorithms for the proposed NOSS scatterometer system is also discussed.

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

Cranbrook, The Earl of.

After a century of scientific investigation, it is now possible to understand Malaysia's complex ecosystem as an essential prerequisite to the successful management for conservation and long term productivity in the area. Contents: The physical setting: Forest types and forest zonation; The dipterocarps; Forest palms; Forest bamboos; Herbaceous flowering plants; Ferns; Higher fungi; Forest tree biology; Forest management; Mammals; Genetic diversity and evolution; Mammals; Distribution and ecology, Earl of Cranbook, Birds; Termites in rain forests; Forest lepidoptera; Freshwaters; Animal conservation strategies; People of the forest.

Basal area growth for 15 tropical trees species in Puerto Rico. Forest

Treesearch

B. R. Parresol

1995-01-01

The tabonuco forest of Puerto Rico support a diverse population of tree species valued for timber, fuel, food, wildlife food and cover, and erosion control among other use. tree basal area growth data spanning 39 years are avaible on 15 species from eigth permanent plots in Luquillo Experimental Forest. The complexity of the rain forest challeges current forest...

Global-scale patterns of forest fragmentation

USGS Publications Warehouse

Riitters, K.; Wickham, J.; O'Neill, R.; Jones, B.; Smith, E.

2000-01-01

We report an analysis of forest fragmentation based on 1-km resolution land-cover maps for the globe. Measurements in analysis windows from 81 km 2 (9 ?? 9 pixels, "small" scale) to 59,049 km 2 (243 ?? 243 pixels, "large" scale) were used to characterize the fragmentation around each forested pixel. We identified six categories of fragmentation (interior, perforated, edge, transitional, patch, and undetermined) from the amount of forest and its occurrence as adjacent forest pixels. Interior forest exists only at relatively small scales; at larger scales, forests are dominated by edge and patch conditions. At the smallest scale, there were significant differences in fragmentation among continents; within continents, there were significant differences among individual forest types. Tropical rain forest fragmentation was most severe in North America and least severe in Europe - Asia. Forest types with a high percentage of perforated conditions were mainly in North America (five types) and Europe - Asia (four types), in both temperate and subtropical regions. Transitional and patch conditions were most common in 11 forest types, of which only a few would be considered as "naturally patchy" (e.g., dry woodland). The five forest types with the highest percentage of interior conditions were in North America; in decreasing order, they were cool rain forest, coniferous, conifer boreal, cool mixed, and cool broadleaf. Copyright ?? 2000 by The Resilience Alliance.

The 2008 South China Freeze and its Impact on the Forests

NASA Astrophysics Data System (ADS)

Zhou, B.; Ai, C.; Wang, Y.; Li, Z.; Cao, Y.; Wang, X.

2008-12-01

An unprecedented calamity caused by snow and freezing rain occurred in South China in 2008. This freeze was closely related to the La Nina phenomenon according to a report from the World Meteorological Organization. The freeze stroke 19 provinces in China, and damaged forests of 19.33 million ha with a standing volume loss of 371 million m3. It is estimated that the direct economic loss in the form of destroyed forests is over $8 billion. The indirect loss in the form of impaired ecological functions, such as water and soil conservation, water resources conservancy, biodiversity and forest carbon pool etc is enormous. The calamity of snow and freezing rain affected the structure and function of forest ecosystems. The snow load and freezing rain caused mechanical damage to the trees, with the species of Pinus massoniana, Cunninghamia lanceolata, Pinus elliottii and Phyllostachys pubescens etc. being the most seriously affected. The cold weather could also cause the physiological hurt to the trees. The change of the biotic components leads to the change of abiotic components in the ecosystems. The sunlight under the canopy was intensified due to the opening up of the canopy. The air temperature in the forest, the nutrient and microorganism in soil, the litterfall dynamic were also affected. The alteration of the forest ecosystem structure brought in the alteration of its functions. The damage of the ecosystem structure weakened the capacity of the water and soil conservation, water resources conservancy and reduced the biodiversity in forest ecosystems. Forest gaps allow more sunlight into the freeze-damaged ecosystem, inducing the invasion of more masculine species. The direction and progress of the community succession was therefore altered. At the same time, the freeze made a great impact on the stability and health of the forest ecosystem, increasing the potential risk of outbreak of forest fire and plant diseases/insect pests. Some suggestions on the rebuilding and recovery of damaged forest were given in this paper.

Climate and the weight/height relationship in sub-Saharan Africa.

PubMed

Hiernaux, J; Rudan, P; Brambati, A

1975-01-01

25 populations of the rain forest and 44 of the open country, all descended from the West-Central African stock which lived in the latter biome, are compared for body weight and height. On a log weight/height diagram, the 69 populations cluster along a straight line which intersects the lines of equal body weight/surface ratio: the shorter the body size, the lower the ratio tends to be. The rain forest populations are concentrated in the lower part of the bivariate distribution. The shortest one, the Mbuti Pygmies, has a very low ratio despite a relatively heavy weight. The shorter stature of the rain forest populations seems to be largely genetic in origin; it probably results from selective pressure exerted by the thermal stres in this hot and wet biome where sweating is of low thermolytic efficiency. The amount of reduction of adult stature depends for a large part on the number of generations spent in the forest by the population. Line A (in figure 1) is similar to a growth trend. The 69 populations differ genetically by the target that growth has to reach on a common log weight/height trend line. They achieve this differentiation through different speeds of growth.

Impact of biomass burning on rainwater acidity and composition in Singapore

NASA Astrophysics Data System (ADS)

Balasubramanian, R.; Victor, T.; Begum, R.

1999-11-01

The Indonesian forest fires that took place from August through October 1997 released large amounts of gaseous and particulate pollutants into the atmosphere. The particulate emissions produced a plume that was easily visible by satellite and significantly affected regional air quality in Southeast Asia. This prolonged haze episode provided an unprecedented opportunity to examine the effects of biomass burning on regional atmospheric chemistry. We undertook a comprehensive field study to assess the influence of biomass burning impacted air masses on precipitation chemistry in Singapore. Major inorganic and organic ions were determined in 104 rain samples collected using an automated wet-only sampler from July through December 1997. Mean pH values ranged from 3.79 to 6.20 with a volume-weighted mean of 4.35. There was a substantially large number of rain events with elevated concentrations of these ions during the biomass burning period. The relatively high concentrations of SO2-4, NO-3, and NH+4 observed during the burning period are attributed to a long residence time of air masses, leading to progressive gas to particle conversion of biomass burning emission components. The decrease in pH of precipitation in response to the increased concentrations of acids is only marginal, which is ascribed to neutralization of acidity by NH3 and CaCO3.

Humus depths under cut and uncut northern hardwood forests

Treesearch

George Hart

1960-01-01

Harvesting timber on lands devoted primarily to watershed management may alter, for better or worse, many features of a forested watershed. One such feature is forest humus. The beneficial role of forest humus in watershed management is widely recognized. A protective mantle of humus serves to cushion the impact of rain, to impede surface runoff, to restrict soil...

The forest ecosystems observatory in Guadeloupe (FWI)

Treesearch

G. Van Laere; Y. Gall; A. Rousteau

2016-01-01

Between 2010 and 2012, Parc National de la Guadeloupe, Office National des Forêts, and Université des Antilles et de la Guyane established 9 permanent 1-ha plots in tropical rain forest of Basse-Terre Island (Guadeloupe). These plots comprise the Guadeloupian Forest Observatory, and are specifically designed for long-term tree growth measurements and forest-dynamics...

Fifty-thousand-year vegetation and climate history of Noel Kempff Mercado National Park, Bolivian Amazon

NASA Astrophysics Data System (ADS)

Burbridge, Rachel E.; Mayle, Francis E.; Killeen, Timothy J.

2004-03-01

Pollen and charcoal records from two large, shallow lakes reveal that throughout most of the past 50,000 yr Noel Kempff Mercado National Park, in northeastern lowland Bolivia (southwestern Amazon Basin), was predominantly covered by savannas and seasonally dry semideciduous forests. Lowered atmospheric CO 2 concentrations, in combination with a longer dry season, caused expansion of dry forests and savannas during the last glacial period, especially at the last glacial maximum. These ecosystems persisted until the mid-Holocene, although they underwent significant species reassortment. Forest communities containing a mixture of evergreen and semideciduous species began to expand between 6000 and 3000 14C yr B.P. Humid evergreen rain forests expanded to cover most of the area within the past 2000 14C yr B.P., coincident with a reduction in fire frequencies. Comparisons between modern pollen spectra and vegetation reveal that the Moraceae-dominated rain forest pollen spectra likely have a regional source area at least 2-3 km beyond the lake shore, whereas the grass- and sedge-dominated savanna pollen spectra likely have a predominantly local source area. The Holocene vegetation changes are consistent with independent paleoprecipitation records from the Bolivian Altiplano and paleovegetation records from other parts of southwestern Amazonia. The progressive expansion in rain forests through the Holocene can be largely attributed to enhanced convective activity over Amazonia, due to greater seasonality of insolation in the Southern Hemisphere tropics driven by the precession cycle according to the Milankovitch Astronomical Theory.

Ecology: Accumulating Threats to Life.

ERIC Educational Resources Information Center

Peterson, Russell W.

1980-01-01

This article identifies the cumulative effects of some environmental problems facing mankind and presents possible alternative futures. The author discusses the pervasive infiltration and detrimental effects in the biosphere of polychlorinated biphenyls, the recent increase in acid rain, the loss of tropical rain forest lands, and future energy…

Trypanocidal activity of extracts from Brazilian Atlantic Rain Forest plant species.

PubMed

Pizzolatti, M G; Koga, A H; Grisard, E C; Steindel, M

2003-01-01

The trypanocidal activity of crude hydro alcoholic extracts and several fractions of 13 plants from Brazilian Atlantic Rain Forest were tested in vitro against epimastigote and trypomastigote forms of Trypanosoma cruzi, the etiological agent of Chagas disease. Crude ethanol extracts with promising in vitro activity (DL50 between 5-10 microg/ml) against epimastigotes were fractionated by solvent partition and further tested against bloodstream form of the parasite. Activity against bloodstream parasites was observed in both dichloromethane and hexane fractions of Polygala sabulosa and P. paniculata.

The ecological variations in thermal infrared emissivity of vegetation. [in Texas, Arizona, New Mexico, and Mexico

NASA Technical Reports Server (NTRS)

Arp, G. K.; Phinney, D. E. (Principal Investigator)

1979-01-01

The author has identified the following significant results. Through a series of contrasts, the statistical significance of differences in emissivity was determined for vegegation in dry and humid deserts, montane and deciduous rain forests, and the temperate region. No significant differences were found between the two types of desert vegetation or among the types of nondesert vegetation. However, the rain forest vegetation was significantly different from that of the temperate region. On a community-wide level, there is some physiological adaptation in plants to their radiational environment.

Spatial and Temporal Patterns of Throughfall Amounts and Solutes in a Tropical Montane Forest - Comparisons with Findings From Lowland Rain Forests

NASA Astrophysics Data System (ADS)

Zimmermann, A.

2007-05-01

The diverse tree species composition, irregular shaped tree crowns and a multi-layered forest structure affect the redistribution of rainfall in lower montane rain forests. In addition, abundant epiphyte biomass and associated canopy humus influence spatial patterns of throughfall. The spatial variability of throughfall amounts controls spatial patterns of solute concentrations and deposition. Moreover, the living and dead biomass interacts with the rainwater during the passage through the canopy and creates a chemical variability of its own. Since spatial and temporal patterns are intimately linked, the analysis of temporal solute concentration dynamics is an important step to understand the emerging spatial patterns. I hypothesized that: (1) the spatial variability of volumes and chemical composition of throughfall is particularly high compared with other forests because of the high biodiversity and epiphytism, (2) the temporal stability of the spatial pattern is high because of stable structures in the canopy (e.g. large epiphytes) that show only minor changes during the short term observation period, and (3) the element concentrations decrease with increasing rainfall because of exhausting element pools in the canopy. The study area at 1950 m above sea level is located in the south Ecuadorian Andes far away from anthropogenic emission sources and marine influences. Rain and throughfall were collected from August to October 2005 on an event and within-event basis for five precipitation periods and analyzed for pH, K, Na, Ca, Mg, NH4+, Cl-, NO3-, PO43-, TN, TP and TOC. Throughfall amounts and most of the solutes showed a high spatial variability, thereby the variability of H+, K, Ca, Mg, Cl- and NO3- exceeded those from a Brazilian tropical rain forest. The temporal persistence of the spatial patterns was high for throughfall amounts and varied depending on the solute. Highly persistent time stability patterns were detected for K, Mg and TOC concentrations. Time stability patterns of solute deposition were somewhat weaker than for concentrations for most of the solutes. Epiphytes strongly affected time stability patterns in that collectors situated below thick moss mats or arboreal bromeliads were in large part responsible for the extreme persistence with low throughfall amounts and high ion concentrations (H+ showed low concentrations). Rainfall solute concentrations were low compared with a variety of other tropical lowland and montane forest sites and showed a small temporal variability during the study period for both between and within-event dynamics, respectively. Throughfall solute concentrations were more within the range when compared with other sites and showed highly variable within-event dynamics. For most of the solutes, within-event concentrations did not reach low, constant concentrations in later event stages, rather concentrations fluctuated (e.g. Cl-) or increased (e.g. K and TOC). The within-event throughfall solute concentration dynamics in this lower montane rain forest contrast to recent observations from lowland tropical rain forests in Panama and Brazil. The observed within-event patterns are attributed (1) to the influence of epiphytes and associated canopy humus, and (2) to low rainfall intensities.

Evaporation from a tropical rain forest, Luquillo Experimental Forest, eastern Puerto Rico

NASA Astrophysics Data System (ADS)

Schellekens, J.; Bruijnzeel, L. A.; Scatena, F. N.; Bink, N. J.; Holwerda, F.

2000-08-01

Evaporation losses from a watertight 6.34 ha rain forest catchment under wet maritime tropical conditions in the Luquillo Experimental Forest, Puerto Rico, were determined using complementary hydrological and micrometeorological techniques during 1996 and 1997. At 6.6 mm d-1 for 1996 and 6.0 mm d-1 for 1997, the average evapotranspiration (ET) of the forest is exceptionally high. Rainfall interception (Ei), as evaluated from weekly throughfall measurements and an average stemflow fraction of 2.3%, accounted for much (62-74%) of the ET at 4.9 mm d-1 in 1996 and 3.7 mm d-1 in 1997. Average transpiration rates (Et) according to a combination of the temperature fluctuation method and the Penman-Monteith equation were modest at 2.2 mm d-1 and 2.4 mm d-1 in 1996 and 1997, respectively. Both estimates compared reasonably well with the water-budget-based estimates (ET - Ei) of 1.7 mm d-1 and 2.2 mm d-1. Inferred rates of wet canopy evaporation were roughly 4 to 5 times those predicted by the Penman-Monteith equation, with nighttime rates very similar to daytime rates, suggesting radiant energy is not the dominant controlling factor. A combination of advected energy from the nearby Atlantic Ocean, low aerodynamic resistance, plus frequent low-intensity rain is thought to be the most likely explanation of the observed discrepancy between measured and estimated Ei.

Simulation of water available for runoff in clearcut forest openings during rain-on-snow events in the western Cascade Range of Oregon and Washington

USGS Publications Warehouse

van Heeswijk, Marijke; Kimball, J.S.; Marks, Danny

1996-01-01

Rain-on-snow events are common on mountain slopes within the transient-snow zone of the Pacific Northwest. These events make more water available for runoff than does precipitation alone by melting the snowpack and by adding a small amount of condensate to the snowpack. In forest openings (such as those resulting from clearcut logging), the amount of snow that accumulates and the turbulent- energy input to the snowpack are greater than below forest stands. Both factors are believed to contribute to a greater amount of water available for runoff during rain-on-snow events in forest openings than forest stands. Because increased water available for runoff may lead to increased downstream flooding and erosion, knowledge of the amount of snowmelt that can occur during rain on snow and the processes that control snowmelt in forest openings is useful when making land-use decisions. Snow accumulation and melt were simulated for clearcut conditions only, using an enery- balance approach that accounts for the most important energy and mass exchanges between a snowpack and its environment. Meteorological measurements provided the input for the simulations. Snow accumulation and melt were not simulated in forest stands because interception of precipitation processes are too complex to simulate with a numerical model without making simplifying assumptions. Such a model, however, would need to be extensively tested against representative observations, which were not available for this study. Snowmelt simulated during three rain-on-snow events (measured in a previous study in a clearcut in the transient-snow zone of the H.J. Andrews Experimental Forest in Oregon) demonstrated that melt generation is most sensitive to turbulent- energy exchanges between the air and the snowpack surface. As a result, the most important climate variable that controls snowmelt is wind speed. Air temperature, however, is a significant variable also. The wind speeds were light, with a maximum of 3.3 meters per second during one event and average wind speeds for all three events ranging from 1.7 to 2.1 meters per second. For observed and estimated conditions, the average simulated snowmelt ranged from 0.2 to 0.8 millimeter liquid water per hour, and turbulent-energy exchange provided 51 percent of the energy that led to snowmelt during the largest of the three rain-on-snow events. When wind speeds were multiplied by a factor of 4, the simulated snowmelt ranged from 1.0 to 2.5 millimeters per hour. Similarly, when wind speeds were multiplied by a factor of 6, the simulated snowmelt ranged from 1.6 to 3.7 millimeters per hour. Turbulent-energy exchange provided a dominant 88 and 92 percent of the energy input to the snowpack during the largest rain-on-snow event when average wind speeds were multiplied by factors of 4 and 6, respectively. During the same event, the contribution to melt by the sum of net solar and net thermal radiation (net all-wave radiation) was roughly equal to the contribution of sensible energy carried by the precipitation itself (advective heat). Estimates of snowmelt resulting from rain on snow for climate conditions other than those observed and estimated in the simulated plot-scale data were expanded by simulating snowmelt for 24-hour presumed rain-on-snow events extracted from the reconstructed, long-term historical climate records for Cedar Lake and Snoqualmie Pass National Weather Service stations in Washington State. The selected events exceeded 75 millimeters of precipitation in 24 hours. When clearcut conditions were assumed to be identical to those at the H.J. Andrews Experimental Forest site and a ripe snowpack that never completely melted was assumed to be available, simulated 24-hour snowmelt ranged from 4.2 to 47.0 millimeters (0.2 to 2.0 millimeters per hour) for low wind speeds (1.5 meters per second) and from 10.3 to 178.8 millimeters (0.4 to 7.5 millimeters per hour) for high wind speeds (8.2 meters per second). The ranges in

Growth of ponderosa pine seedlings as affected by air pollution

NASA Astrophysics Data System (ADS)

Momen, B.; Anderson, P. D.; Houpis, J. L. J.; Helms, J. A.

The effect of air pollution on seedling survival and competitive ability is important to natural and artificial regeneration of forest trees. Although biochemical and physiological processes are sensitive indicators of pollution stress, the cumulative effects of air pollutants on seedling vigor and competitive ability may be assessed directly from whole-plant growth characteristics such as diameter, height, and photosynthetic area. A few studies that have examined intraspecific variation in seedling response to air pollution indicate that genotypic differences are important in assessing potential effects of air pollution on forest regeneration. Here, we studied the effects of acid rain (no-rain, pH 5.1 rain, pH 3.0 rain) and ozone (filtered, ambient, twice-ambient) in the field on height, diameter, volume, the height:diameter ratio, maximum needle length, and time to reach maximum needle length in seedlings of three families of ponderosa pine ( Pinus ponderosa Dougl. ex Laws). Seedling diameter, height, volume, and height:diameter ratio related significantly to their pre-treatment values. Twice-ambient ozone decreased seedling diameter compared with ozone-filtered air. A significant family-by-ozone interaction was detected for seedling height, as the height of only one of the three families was decreased by twice-ambient ozone compared with the ambient level. Seedling diameter was larger and the height:diameter ratio was smaller under pH 3.0 rain compared to either the no-rain or the pH 5.1-rain treatment. This suggests greater seedling vigor, perhaps due to a foliar fertilization effect of the pH 3.0 rain.

Cascading Effects of Canopy Opening and Debris Deposition from a Large-Scale Hurricane Experiment in a Tropical Rain Forest

Treesearch

Aaron B. Shiels; Grizelle Gonzalez; D. Jean Lodge; Michael R Willig; Jess K. Zimmerman

2015-01-01

Intense hurricanes disturb many tropical forests, but the key mechanisms driving post-hurricane forest changes are not fully understood. In Puerto Rico, we used a replicated factorial experiment to determine the mechanisms of forest change associated with canopy openness and organic matter (debris) addition. Cascading effects from canopy openness accounted for...

Spread of an invasive grass in closed-canopy deciduous forests across local and regional environmental gradients

Treesearch

Cynthia D. Huebner

2010-01-01

Spread of Microstegium vimineum, an invasive exotic grass, in closed-canopy forests of West Virginia, U.S. was evaluated across a local (roadside to forest interior) and regional (across two geographic provinces) environmental gradient. Seed dispersal distances from roadside populations into forest interiors based on seed rain and soil seed bank data...

[Soil seed bank formation during early revegetation of areas affected by mining in a tropical rain forest of Chocó, Colombia].

PubMed

Valois-Cuesta, Hamleth; Martínez-Ruiz, Carolina; Urrutia-Rivas, Yorley

2017-03-01

Mining is one of the main economic activities in many tropical regions and is the cause of devastation of large areas of natural tropical forests. The knowledge of the regenerative potential of mining disturbed areas provides valuable information for their ecological restoration. The aim of this study was to evaluate the effect of age of abandonment of mines and their distance from the adjacent forest, on the formation of soil seed bank in abandoned mines in the San Juan, Chocó, Colombia. To do this, we determined the abundance and species composition of the soil seed bank, and the dynamics of seed rain in mines of different cessation period of mining activity (6 and 15 years), and at different distances from the adjacent forest matrix (50 and 100 m). Seed rain was composed by five species of plants with anemocorous dispersion, and was more abundant in the mine of 6 years than in the mine of 15 years. There were no significant differences in the number of seeds collected at 50 m and 100 m from the adjacent forest. The soil seed bank was represented by eight species: two with anemocorous dispersion (common among the seed rain species) and the rest with zoochorous dispersion. The abundance of seeds in the soil did not vary with the age of the mine, but was higher at close distances to the forest edge than far away. During the early revegetation, the formation of the soil seed bank in the mines seems to be related to their proximity to other disturbed areas, rather than their proximity to the adjacent forest or the cessation activity period of mines. Therefore, the establishment of artificial perches or the maintenance of isolated trees in the abandoned mines could favour the arrival of bird-dispersed seeds at mines. However, since the soil seed bank can be significantly affected by the high rainfall in the study area, more studies are needed to evaluate management actions to encourage soil seed bank formation in mines of high-rainfall environments in the Chocó region.

Prevalence of pterygium and cataract in indigenous populations of the Brazilian Amazon rain forest.

PubMed

Paula, J S; Thorn, F; Cruz, A A V

2006-05-01

To compare the prevalence of pterygium and cataract in four indigenous populations of the Brazilian Amazonian rain forest (Arawak, Tukano, Maku, and Yanomami) with different ethnic and social behaviour backgrounds. A cross-sectional pterygium and cataract survey was performed in 624 adult Indians of the Brazilian rain forest belonging to four different ethnic groups. The Indians were classified according to their social behaviour in two groups: Arawak and Tukano (group 1) and Maku and Yanomami (group 2). Slit-lamp biomicroscopy was employed to examine the entire sample. All subjects were classified as 1 or 0 according to the presence or absence pterygium and cataract. Sex and age were also recorded. chi(2)-tests revealed that the prevalence of pterygium and cataract differed significantly between groups 1 and 2. For pterygia: 36.6% (97/265) and 5.0% (18/359), respectively (chi(2)=101.2, P<0.0001), and for cataracts: 24.5% (65/265) and 13.7% (49/359) respectively (chi(2)=12.09, P=0.0005). Gender was not associated with pterygium (P=0.1326) and cataract (P=0.2263) in both groups. Elderly subjects showed a significantly higher prevalence of cataract (P<0.0001). The prevalence of pterygia did not increase with age (P=0.8079) in both groups. Indians of group 1 have higher prevalence of pterygia and cataract than Indians of group 2. Social behaviour, especially the rate of sun exposure, appears to be the main factor for the different rates of pterygium and cataract displayed by these indigenous people of the Brazilian rain forest.

Native plant propagation and habitat restoration at Hakalau Forest National Wildlie Refuge, Hawaii

Treesearch

Baron Horiuchi; Jack Jeffrey

2002-01-01

Hakalau Forest NWR was established in 1985 under the authority of the Endangered Species Act to preserve and protect five species of endangered forest birds and their rain forest habitat. While most of the 32,730 acre refuge is closed canopy forest, over one hundred years of cattle grazing, logging and burning have convened about 5,000 acres (2,023 ha) of upper...

Management and utilization of forest resources in Papua New Guinea

Treesearch

P.B.L. Srivastava

1992-01-01

Papua New Guinea, with an area of about 46.7 million ha and population of 3.7 million, is blessed with a large natural forest resource. Over 80 percent of the land is covered with forests of various types, ranging from swamp and lowland rain forests in coastal plains to alpine vegetation and moss forests in the highlands, most of which are owned by the people. About 15...

Canada issues booklet describing acid rain

NASA Astrophysics Data System (ADS)

A booklet recently released by Environment Canada describes acid rain in terms easily understood by the general public. Although Acid Rain — The Facts tends somewhat to give the Canadian side of this intercountry controversial subject, it nevertheless presents some very interesting, simple statistics of interest to people in either the U.S. or Canada. Copies of the booklet can be obtained from Inquiry Environment Canada, Ottawa, Ontario K1A OH3, Canada, tel. 613-997-2800.The booklet points out that acid rain is caused by emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx). Once released into the atmosphere, these substances can be carried long distances by prevailing winds and return to Earth as acidic rain, snow, fog, or dust. The main sources of SO2 emissions in North America are coal-fired power generating stations and nonferrous ore smelters. The main sources of NOx emissions are vehicles and fuel combustion. From economical and environmental viewpoints, Canada believes acid rain is one of the most serious problems presently facing the country: increasing the acidity of more than 20% of Canada's 300,000 lakes to the point that aquatic life is depleted and acidity of soil water and shallow groundwater is increasing, causing decline in forest growth and water fowl populations, and eating away at buildings and monuments. Acid rain is endangering fisheries, tourism, agriculture, and forest resources in an area of 2.6 million km2 (one million square miles) of eastern Canada, about 8% of Canada's gross national product.

Tropical Rainforest Education. ERIC Digest.

ERIC Educational Resources Information Center

Rillero, Peter

This digest provides four guideposts for tropical rainforest education: (1) structure; (2) location and climate; (3) importance; and (4) conservation of resources. Research is cited and background information provided about the layers of life and the adaptations of life within the tropical rain forest. Aspects of life within and near rain forests…

Cloud water in windward and leeward mountain forests: The stable isotope signature of orographic cloud water

USGS Publications Warehouse

Scholl, M.A.; Giambelluca, T.W.; Gingerich, S.B.; Nullet, M.A.; Loope, L.L.

2007-01-01

Cloud water can be a significant hydrologic input to mountain forests. Because it is a precipitation source that is vulnerable to climate change, it is important to quantify amounts of cloud water input at watershed and regional scales. During this study, cloud water and rain samples were collected monthly for 2 years at sites on windward and leeward East Maui. The difference in isotopic composition between volume‐weighted average cloud water and rain samples was 1.4‰ δ18O and 12‰ δ2H for the windward site and 2.8‰ δ18O and 25‰ δ2H for the leeward site, with the cloud water samples enriched in 18O and 2H relative to the rain samples. A summary of previous literature shows that fog and/or cloud water is enriched in 18O and 2H compared to rain at many locations around the world; this study documents cloud water and rain isotopic composition resulting from weather patterns common to montane environments in the trade wind latitudes. An end‐member isotopic composition for cloud water was identified for each site and was used in an isotopic mixing model to estimate the proportion of precipitation input from orographic clouds. Orographic cloud water input was 37% of the total precipitation at the windward site and 46% at the leeward site. This represents an estimate of water input to the forest that could be altered by changes in cloud base altitude resulting from global climate change or deforestation.

Changes in photosynthesis and leaf characteristics with tree height in five dipterocarp species in a tropical rain forest.

PubMed

Kenzo, Tanaka; Ichie, Tomoaki; Watanabe, Yoko; Yoneda, Reiji; Ninomiya, Ikuo; Koike, Takayoshi

2006-07-01

Variations in leaf photosynthetic, morphological and biochemical properties with increasing plant height from seedlings to emergent trees were investigated in five dipterocarp species in a Malaysian tropical rain forest. Canopy openness increased significantly with tree height. Photosynthetic properties, such as photosynthetic capacity at light saturation, light compensation point, maximum rate of carboxylation and maximum rate of photosynthetic electron transport, all increased significantly with tree height. Leaf morphological and biochemical traits, such as leaf mass per area, palisade layer thickness, nitrogen concentration per unit area, chlorophyll concentration per unit dry mass and chlorophyll to nitrogen ratio, also changed significantly with tree height. Leaf properties had simple and significant relationships with tree height, with few intra- and interspecies differences. Our results therefore suggest that the photosynthetic capacity of dipterocarp trees depends on tree height, and that the trees adapt to the light environment by adjusting their leaf morphological and biochemical properties. These results should aid in developing models that can accurately estimate carbon dioxide flux and biomass production in tropical rain forests.

Analysis on the vegetation phenology of tropical seasonal rain forest in South America

NASA Astrophysics Data System (ADS)

Liang, B.; Chen, X.

2016-12-01

Using Global Land Surface Satellite (GLASS) LAI data during 1982 to 2003, we analyzed spatial and temporal variations of vegetation phenology in the tropical seasonal rain forest of South America. Several methods were used to fit seasonal LAI curves and extract start (SOS) and end (EOS) of the growing season. The results show that Fourier function can most effectively fit LAI curves, and yearly RMSEs for differences between observed and fitted LAI values are less than 0.01. The SOS ranged from 250 to 350 days of year, and occurred earlier in west than in east. Contrarily, the EOS were between 120 and 180 days of year, and appeared earlier in east than in west. Thus, the growing season was longer in west than in east. With regard to linear trends, SOS shows a significant advancement at 7% of pixels and a significant delay at 13% of pixels, whereas EOS advanced significantly at 16% of pixels and was delayed significantly at 18% of pixels. Preseason precipitation is the main influence factor of SOS and EOS in the tropical seasonal rain forest of South America.

Protecting rain forests and forager's rights using LANDSAT imagery

NASA Technical Reports Server (NTRS)

Wilkie, David S.

1991-01-01

Creating rain forest reserves is vital given the global decline in biodiversity. Yet, the plants and animals that will be protected from untrammeled commercial exploitation within such reserves constitute essential resources for indigenous foragers and farmers. Balancing the needs of local subsistence level populations with the goals of national and international conservation agencies requires a thorough understanding of the mutual impacts that arise from the interaction of park and people. In the Ituri forest of Zaire, LANDSAT TM image analysis and GPS ground truth data were used to locate human settlements so that boundaries of the proposed Okapi Reserve could be chosen to minimize its impact on the subsistence practices of the local foragers and farmers. Using satellite imagery in conjunction with cultural information should help to ensure traditional resource exploitation rights of indigenous peoples whilst simultaneously protecting the largest contiguous area of undisturbed forest.

Can extractive reserves save the rain forest: A ecological and socioeconomic comparison of non-timber forest product extraction systems in Peten, Guatemala, and West Kalimantan, Indonesia

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

Salafsky, N.; Dugelby, B.L.; Terborgh, J.W.

1992-04-01

Extractive reserves in tropical rain forests, in which only non-timber products are harvested, have been heralded by some conservationists as a means of maintaining biodiversity while providing income for local people. The study of extraction systems in Peten, Guatemala, and in West Kalimantan, Indonesia, leads to a more tempered conclusion, for while the Peten program was quite successful, the Kalimantan program was not. The study finds the success of an extractive reserve to be contingent on: (1) ecological conditions, and (2) socioeconomic and political factors. Although the study focuses on market-oriented extractive reserves, many of the issues discussed apply asmore » well to other land uses such as the collection of non-timber forest products for household consumption or small-scale timber extraction.« less

Towards ground-truthing of spaceborne estimates of above-ground biomass and leaf area index in tropical rain forests

NASA Astrophysics Data System (ADS)

Köhler, P.; Huth, A.

2010-05-01

The canopy height of forests is a key variable which can be obtained using air- or spaceborne remote sensing techniques such as radar interferometry or lidar. If new allometric relationships between canopy height and the biomass stored in the vegetation can be established this would offer the possibility for a global monitoring of the above-ground carbon content on land. In the absence of adequate field data we use simulation results of a tropical rain forest growth model to propose what degree of information might be generated from canopy height and thus to enable ground-truthing of potential future satellite observations. We here analyse the correlation between canopy height in a tropical rain forest with other structural characteristics, such as above-ground biomass (AGB) (and thus carbon content of vegetation) and leaf area index (LAI). The process-based forest growth model FORMIND2.0 was applied to simulate (a) undisturbed forest growth and (b) a wide range of possible disturbance regimes typically for local tree logging conditions for a tropical rain forest site on Borneo (Sabah, Malaysia) in South-East Asia. It is found that for undisturbed forest and a variety of disturbed forests situations AGB can be expressed as a power-law function of canopy height h (AGB=a·hb) with an r2~60% for a spatial resolution of 20 m×20 m (0.04 ha, also called plot size). The regression is becoming significant better for the hectare wide analysis of the disturbed forest sites (r2=91%). There seems to exist no functional dependency between LAI and canopy height, but there is also a linear correlation (r2~60%) between AGB and the area fraction in which the canopy is highly disturbed. A reasonable agreement of our results with observations is obtained from a comparison of the simulations with permanent sampling plot data from the same region and with the large-scale forest inventory in Lambir. We conclude that the spaceborne remote sensing techniques have the potential to quantify the carbon contained in the vegetation, although this calculation contains due to the heterogeneity of the forest landscape structural uncertainties which restrict future applications to spatial averages of about one hectare in size. The uncertainties in AGB for a given canopy height are here 20-40% (95% confidence level) corresponding to a standard deviation of less than ±10%. This uncertainty on the 1 ha-scale is much smaller than in the analysis of 0.04 ha-scale data. At this small scale (0.04 ha) AGB can only be calculated out of canopy height with an uncertainty which is at least of the magnitude of the signal itself due to the natural spatial heterogeneity of these forests.

A New Infrared Desert Dust Index over French Guyana Rain forest: First results

NASA Astrophysics Data System (ADS)

Molinie, J.; Barnacin, E.; Henry, J. L.; Gobinddass, M. L.; Panechou-Pulcherie, K.; Feuillard, T.; Nagau, J.

2017-12-01

Recently a NASA researcher showed the role of desert dust contribution for the Amazonian rain forest. In another hand, desert dust impact population health when PM 10 level reached values around and upper the PM 10 threshold of the 50 µg m-3, established by the World Health Organization (WHO). Infrared Desert Dust Index (IDDI) developed by Legrand with Meteosat infrared images, allow the following of desert dust plumes over semi-arid land. In French Guiana the WHO threshold is currently overpass in measurements done by ORA air quality network, in the two main towns located close to the coast. For inland population, it is very difficult to have continuous dust measures due to the low infrastructure supplies. We need to develop a tools in order to follow the crossing of desert dust over the French Guyana rain forest, from the coast to inland villages. Following the IDDI concept and comparing with VIIRS AOT EDR result over the same area, a modified IDDI for Amazonian region (IDDI_A) has been proposed to identify the dusty pixels over the forest. Despite of high cloud presence, a good correlation between AOT EDR and IDDI_A was obtained. The IDDI_A calculation has been applied over French Guiana area for different PM 10 level at Cayenne, a town along the coast.

Modeling climate change impacts on the forest sector

Treesearch

John R. Mills; Ralph Alig; Richard W. Haynes; Darius M. Adams

2000-01-01

The forest sector has had a relatively long history of applying sectorial models to estimate the effects of atmospheric issues such as acid rain, climate change, and the forestry impacts of reduced atmospheric ozone. The models of the forest sector vary in scope and complexity but share a number of common features and databases.

Height-related changes in leaf photosynthetic traits in diverse Bornean tropical rain forest trees.

PubMed

Kenzo, Tanaka; Inoue, Yuta; Yoshimura, Mitsunori; Yamashita, Megumi; Tanaka-Oda, Ayumi; Ichie, Tomoaki

2015-01-01

Knowledge of variations in morphophysiological leaf traits with forest height is essential for quantifying carbon and water fluxes from forest ecosystems. Here, we examined changes in leaf traits with forest height in diverse tree species and their role in environmental acclimation in a tropical rain forest in Borneo that does not experience dry spells. Height-related changes in leaf physiological and morphological traits [e.g., maximum photosynthetic rate (Amax), stomatal conductance (gs), dark respiration rate (Rd), carbon isotope ratio (δ(13)C), nitrogen (N) content, and leaf mass per area (LMA)] from understory to emergent trees were investigated in 104 species in 29 families. We found that many leaf area-based physiological traits (e.g., A(max-area), Rd, gs), N, δ(13)C, and LMA increased linearly with tree height, while leaf mass-based physiological traits (e.g., A(max-mass)) only increased slightly. These patterns differed from other biomes such as temperate and tropical dry forests, where trees usually show decreased photosynthetic capacity (e.g., A(max-area), A(max-mass)) with height. Increases in photosynthetic capacity, LMA, and δ(13)C are favored under bright and dry upper canopy conditions with higher photosynthetic productivity and drought tolerance, whereas lower R d and LMA may improve shade tolerance in lower canopy trees. Rapid recovery of leaf midday water potential to theoretical gravity potential during the night supports the idea that the majority of trees do not suffer from strong drought stress. Overall, leaf area-based photosynthetic traits were associated with tree height and the degree of leaf drought stress, even in diverse tropical rain forest trees.

Multidecadal stability in tropical rain forest structure and dynamics across an old-growth landscape

PubMed Central

Clark, Deborah A.; Oberbauer, Steven F.; Kellner, James R.

2017-01-01

Have tropical rain forest landscapes changed directionally through recent decades? To answer this question requires tracking forest structure and dynamics through time and across within-forest environmental heterogeneity. While the impacts of major environmental gradients in soil nutrients, climate and topography on lowland tropical rain forest (TRF) structure and function have been extensively analyzed, the effects of the shorter environmental gradients typical of mesoscale TRF landscapes remain poorly understood. To evaluate multi-decadal performance of an old-growth TRF at the La Selva Biological Station, Costa Rica, we established 18 0.5-ha annually-censused forest inventory plots in a stratified-random design across major landscape edaphic gradients. Over the 17-year study period, there were moderate differences in stand dynamics and structure across these gradients but no detectable difference in woody productivity. We found large effects on forest structure and dynamics from the mega-Niño event at the outset of the study, with subdecadal recovery and subsequent stabilization. To extend the timeline to >40 years, we combined our findings with those from earlier studies at this site. While there were annual to multiannual variations in the structure and dynamics, particularly in relation to local disturbances and the mega-Niño event, at the longer temporal scale and broader spatial scale this landscape was remarkably stable. This stability contrasts notably with a current hypothesis of increasing biomass and dynamics of TRF, which we term the Bigger and Faster Hypothesis (B&FHo). We consider possible reasons for the contradiction and conclude that it is currently not possible to independently assess the vast majority of previously published B&FHo evidence due to restricted data access. PMID:28981502

Relationships among net primary productivity, nutrients and climate in tropical rain forest: A pan-tropical analysis

USGS Publications Warehouse

Cleveland, Cory C.; Townsend, Alan R.; Taylor, Philip; Alvarez-Clare, Silvia; Bustamante, Mercedes M.C.; Chuyong, George; Dobrowski, Solomon Z.; Grierson, Pauline; Harms, Kyle E.; Houlton, Benjamin Z.; Marklein, Alison; Parton, William; Porder, Stephen; Reed, Sasha C.; Sierra, Carlos A.; Silver, Whendee L.; Tanner, Edmund V.J.; Wieder, William R.

2011-01-01

Tropical rain forests play a dominant role in global biosphere-atmosphere CO2 exchange. Although climate and nutrient availability regulate net primary production (NPP) and decomposition in all terrestrial ecosystems, the nature and extent of such controls in tropical forests remain poorly resolved. We conducted a meta-analysis of carbon-nutrient-climate relationships in 113 sites across the tropical forest biome. Our analyses showed that mean annual temperature was the strongest predictor of aboveground NPP (ANPP) across all tropical forests, but this relationship was driven by distinct temperature differences between upland and lowland forests. Within lowland forests (< 1000 m), a regression tree analysis revealed that foliar and soil-based measurements of phosphorus (P) were the only variables that explained a significant proportion of the variation in ANPP, although the relationships were weak. However, foliar P, foliar nitrogen (N), litter decomposition rate (k), soil N and soil respiration were all directly related with total surface (0–10 cm) soil P concentrations. Our analysis provides some evidence that P availability regulates NPP and other ecosystem processes in lowland tropical forests, but more importantly, underscores the need for a series of large-scale nutrient manipulations – especially in lowland forests – to elucidate the most important nutrient interactions and controls.

Tropical rain forest biogeochemistry in a warmer world: initial results from a novel warming experiment in a Puerto Rico tropical forest

NASA Astrophysics Data System (ADS)

Reed, S.; Cavaleri, M. A.; Alonso-Rodríguez, A. M.; Kimball, B. A.; Wood, T. E.

2016-12-01

Tropical forests represent one of the planet's most active biogeochemical engines. They account for the dominant proportion of Earth's live terrestrial plant biomass, nearly one-third of all soil carbon, and exchange more CO2 with the atmosphere than any other biome. In the coming decades, the tropics will experience extraordinary changes in temperature, and our understanding of how this warming will affect biogeochemical cycling remains notably poor. Given the large amounts of carbon tropical forests store and cycle, it is no surprise that our limited ability to characterize tropical forest responses to climate change may represent the largest hurdle in accurately predicting Earth's future climate. Here we describe initial results from the world's first tropical forest field warming experiment, where forest understory plants and soils are being warmed 4 °C above ambient temperatures. This Tropical Responses to Altered Climate Experiment (TRACE) was established in a rain forest in Puerto Rico to investigate the effects of increased temperature on key biological processes that control tropical forest carbon cycling, and to establish the steps that need to be taken to resolve the uncertainties surrounding tropical forest responses to warming. In this talk we will describe the experimental design, as well as the wide range of measurements being conducted. We will also present results from the initial phase of warming, including data on how increased temperatures from infrared lamp warming affected soil moisture, soil respiration rates, a suite of carbon pools, soil microbial biomass, nutrient availability, and the exchange of elements between leaf litter and soil. These data represent a first look into tropical rain forest responses to an experimentally-warmed climate in the field, and provide exciting insight into the non-linear ways tropical biogeochemical cycles respond to change. Overall, we strive to improve Earth System Model parameterization of the pools and fluxes of water, carbon, and nutrients in tropical forested ecosystems and the data shown will highlight how these cycles are coupled and independently altered by warming.

Richness and Abundance of Ichneumonidae in a Fragmented Tropical Rain Forest.

PubMed

Ruiz-Guerra, B; Hanson, P; Guevara, R; Dirzo, R

2013-10-01

Because of the magnitude of land use currently occurring in tropical regions, the local loss of animal species due to habitat fragmentation has been widely studied, particularly in the case of vertebrates. Many invertebrate groups and the ichneumonid wasps in particular, however, have been poorly studied in this context, despite the fact that they are one of the most species-rich groups and play an important role as regulators of other insect populations. Here, we recorded the taxonomic composition of ichneumonid parasitoids and assessed their species richness, abundance, similarity, and dominance in the Los Tuxtlas tropical rain forest, Mexico. We compared two forest types: a continuous forest (640 ha) and a forest fragment (19 ha). We sampled ichneumonids using four malaise traps in both forest types during the dry (September-October) and rainy (March-April) seasons. A total of 104 individuals of Ichneumonidae belonging to 11 subfamilies, 18 genera, and 42 species were collected in the continuous forest and 11 subfamilies, 15 genera, and 24 species were collected in the forest fragment. Species richness, abundance, and diversity of ichneumonids were greater in the continuous forest than in the forest fragment. We did not detect differences between seasons. Species rank/abundance curves showed that the ichneumonid community between the forest types was different. Species similarity between forest types was low. The most dominant species in continuous forest was Neotheronia sp., whereas in the forest fragment, it was Orthocentrus sp. Changes in the ichneumonid wasp community may compromise important tropical ecosystem processes.

Nutrient allocation among plant organs across 13 tree species in three Bornean rain forests with contrasting nutrient availabilities.

PubMed

Aoyagi, Ryota; Kitayama, Kanehiro

2016-07-01

Allocation of nitrogen (N) and phosphorus (P) among plant organs is an important factor regulating growth rate, which is a key ecological process associated with plant life-history strategies. However, few studies have explored how N and P investment in photosynthetic (leaves) and non-photosynthetic (stems and roots) organs changes in relation to depletion of each element. We investigated nutrient concentrations of plant organs in relation to whole-plant nutrient concentration (total nutrient weight per total biomass) as an index of nutrient status of each individual using the saplings of the 13 species in three tropical rain forests with contrasting N and P availabilities (tropical evergreen forests and tropical heath forests). We found a steeper decrease in foliar N concentration than foliar P concentration with decreasing whole-plant nutrient concentration. Moreover, the steeper decrease in foliar N concentration was associated with relatively stable N concentration in stems, and vice versa for P. We suggest that the depletion of N is associated with a rapid dilution of foliar N because the cell walls in non-photosynthetic organs function as an N sink. On the other hand, these species can maintain foliar P concentration by decreasing stem P concentrations despites the depletion of P. Our results emphasize the significance of non-photosynthetic organs as an N sink for understanding the variation of foliar nutrient concentrations for the tree species in the three Bornean rain forests with different N and P availabilities.

A laboratory facility for research on wind-driven rain intrusion in building envelope assemblies

Treesearch

Samuel V. Glass

2010-01-01

Moisture management is critical for durable, energy-efficient buildings. To address the need for research on wind-driven rain intrusion in wall assemblies, the U.S. Forest Products Laboratory is developing a new facility. This paper describes the underlying principle of this facility and its capabilities.

Traditional knowledge and use of wild mushrooms by Mixtecs or Ñuu savi, the people of the rain, from Southeastern Mexico.

PubMed

Santiago, Faustino Hernández; Moreno, Jesús Pérez; Cázares, Beatriz Xoconostle; Suárez, Juan José Almaraz; Trejo, Enrique Ojeda; de Oca, Gerardo Mata Montes; Aguilar, Irma Díaz

2016-09-05

Mexico is an important global reservoir of biological and cultural richness and traditional knowledge of wild mushrooms. However, there is a high risk of loss of this knowledge due to the erosion of traditional human cultures which is related with the rapid acculturation linked to high migration of rural populations to cities and the U.S.A., and the loss of natural ecosystems. The Mixtec people, the third largest native group in Mexico only after the Nahua and the Maya, maintain ancient traditions in the use and knowledge of wild mushrooms. Paradoxically, there are few studies of the Mixtec ethnomycology. This study shows our ethnomycological research, mainly focused on knowledge and use of wild mushrooms in communities of the Mixteca Alta, in southeastern Mexico. We hypothesized that among the studied communities those with a combination of higher vegetation cover of natural pine and oak forests, lower soil erosion and higher economic margination had a greater richness and knowledge of wild mushrooms. Our study therefore aimed to record traditional knowledge, use, nomenclature and classification of wild mushrooms in four Mixtec communities and to analyze how these aspects vary according to environmental and cultural conditions among the studied communities. In order to analyze the cultural significance of wild mushrooms for the Mixtec people, 116 non-structured and semi-structured interviews were performed from 2009 to 2014. Information about the identified species, particularly the regional nomenclature and classification, their edibility, toxicity and ludic uses, the habitat of useful mushrooms, traditional recipes and criteria to differentiate between toxic and edible species, and mechanisms of knowledge transmission were studied. The research had the important particularity that the first author is Mixtec, native of the study area. A comparative qualitative analysis between the richness of fungal species used locally and the official information of the natural vegetation cover, soil erosion and economic marginalization in each of the studied communities was conducted. A total of 106 species of mushrooms were identified growing in pine and oak forest, deciduous tropical forest and grassland; among the identified mushrooms we recorded 26 species locally consumed, 18 considered toxic, 6 having ludic uses and the remaining 56 species not being used in the studied areas but some of them having potential as food (56 species) or medicine (28 species). We recorded that 80, 22 and 4 species are ectomycorrhizal, saprotrophic and parasites, respectively. Our study shows that a complex and accurate knowledge related with the use, nomenclature, classification, ecology, gastronomy of wild mushrooms has been developed by Mixtecs; and that there is a relation between natural vegetation cover, lower soil erosion and higher economic marginalization and richness, knowledge and use of mushrooms in the studied communites. Our study showed that conservation and adaptation of ancestral mycological knowledge survives mainly through oral transmition, maintenance of cultural identity, forest protection, preservation native language and also paradoxically through the current socieconomical marginality among the Mixtec people. We also found that those studied communities with a combination of higher vegetation cover of natural pine and oak forests, lower soil erosion and higher economic marginalization showed a greater richness and knowledge of wild mushrooms. Use and sustainable management of wild mushrooms can be an alternative for local integrated development, but local knowledge and traditional worldview should be included into the regional programs of Mixtec biocultural conservation.

Kriging Direct and Indirect Estimates of Sulfate Deposition: A Comparison

Treesearch

Gregory A. Reams; Manuela M.P. Huso; Richard J. Vong; Joseph M. McCollum

1997-01-01

Due to logistical and cost constraints, acidic deposition is rarely measured at forest research or sampling locations. A crucial first step to assessing the effects of acid rain on forests is an accurate estimate of acidic deposition at forest sample sites. We examine two methods (direct and indirect) for estimating sulfate deposition at atmospherically unmonitored...

Air Pollution, Acid Rain, and the Future of Forests. Worldwatch Paper 58.

ERIC Educational Resources Information Center

Postel, Sandra

This book traces centuries of human use and abuse of forest ecosystems by discussing past decades of intense burning, grazing, and timber cutting that added to the natural acidification of the soil. Air pollutants and acids generated by industrial activities worldwide are also considered. Many forests in Europe and North America now receive as…

Reduced-impact logging and temporal activity of understorey bats in lowland Amazonia

Treesearch

Ivan Castro Arellano; Steven J. Presley; Michael R. Willig; Joseph M. Wunderle; Luiz N. Saldanha

2009-01-01

Because global timber demands continue to threaten tropical rain forests, identification of sustainable use forest management protocols that meet human needs while preserving biodiversity is critical. Reduced-impact logging (RIL) protocols are increasingly common in the tropics and may be a viable option for sustainable forest use; however, few studies have documented...

Fagaceae tree species allocate higher fraction of nitrogen to photosynthetic apparatus than Leguminosae in Jianfengling tropical montane rain forest, China

PubMed Central

Cheng, Ruimei; Shi, Zuomin; Xu, Gexi; Liu, Shirong; Centritto, Mauro

2018-01-01

Variation in photosynthetic-nitrogen use efficiency (PNUE) is generally affected by several factors such as leaf nitrogen allocation and leaf diffusional conductances to CO2, although it is still unclear which factors significantly affect PNUE in tropical montane rain forest trees. In this study, comparison of PNUE, photosynthetic capacity, leaf nitrogen allocation, and diffusional conductances to CO2 between five Fagaceae tree species and five Leguminosae tree species were analyzed in Jianfengling tropical montane rain forest, Hainan Island, China. The result showed that PNUE of Fagaceae was significantly higher than that of Leguminosae (+35.5%), attributed to lower leaf nitrogen content per area (Narea, –29.4%). The difference in nitrogen allocation was the main biochemical factor that influenced interspecific variation in PNUE of these tree species. Fagaceae species allocated a higher fraction of leaf nitrogen to the photosynthetic apparatus (PP, +43.8%), especially to Rubisco (PR, +50.0%) and bioenergetics (PB +33.3%) in comparison with Leguminosae species. Leaf mass per area (LMA) of Leguminosae species was lower than that of Fagaceae species (-15.4%). While there was no significant difference shown for mesophyll conductance (gm), Fagaceae tree species may have greater chloroplast to total leaf surface area ratios and that offset the action of thicker cell walls on gm. Furthermore, weak negative relationship between nitrogen allocation in cell walls and in Rubisco was found for Castanopsis hystrix, Cyclobalanopsis phanera and Cy. patelliformis, which might imply that nitrogen in the leaves was insufficient for both Rubisco and cell walls. In summary, our study concluded that higher PNUE might contribute to the dominance of most Fagaceae tree species in Jianfengling tropical montane rain forest. PMID:29390007

Chemical and isotopic signature of old groundwater and magmatic solutes in a Costa Rican rain forest: Evidence from carbon, helium, and chlorine

NASA Astrophysics Data System (ADS)

Genereux, David P.; Webb, Mathew; Solomon, D. Kip

2009-08-01

C, He, and Cl concentrations and isotopes in groundwater and surface water in a lowland Costa Rican rain forest are consistent with the mixing of two distinct groundwaters: (1) high-solute bedrock groundwater representing interbasin groundwater flow (IGF) into the rain forest and (2) low-solute local groundwater recharged in the lowlands. In bedrock groundwater, high δ13C (-4.89‰), low 14C (7.98 pM), high R/RA for He (6.88), and low 36Cl/Cl (17 × 10-15) suggest that elevated tracer concentrations are derived from magmatic outgassing and/or weathering of volcanic rock beneath nearby Volcan Barva. In local groundwater, the magmatic signature is absent, and data suggest atmospheric sources for He and Cl and a biogenic soil gas CO2 source for dissolved inorganic carbon. Dating of 14C suggests that the age of bedrock groundwater is 2400-4000 years (most likely at the lower end of the range). Local groundwater has 14C > 100 pM, indicating the presence of "bomb carbon" and thus ages less than ˜55 years. Overall, data are consistent with a conceptual hydrologic model originally proposed on the basis of water budget and major ion data: (1) large variation in solute concentrations can be explained by mixing of the two distinct groundwaters, (2) bedrock groundwater is much older than local groundwater, (3) elevated solute concentrations in bedrock groundwater are derived from volcanic fluids and/or rock, and (4) local groundwater has not interacted with volcanic rock. Tracers with different capabilities converge on the same hydrologic interpretation. Also, transport of magmatic CO2 into the lowland rain forest via IGF seems to be significant relative to other large ecosystem-level carbon fluxes.

Late Holocene and modern pollen records from three sites in Shannon and Carter Counties, southeast Missouri Ozarks

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

Huber, J.K.

Palynological investigations of a small sinkhole bog (Buttonbush Bog) and two archaeological sites (Round Spring Shelter, Round Spring Site 23SH19 and Gooseneck Site 23CT54) located in Shannon and Carter counties, Missouri provide a 3,100 year record of vegetational change. Bryophytic polsters and surface samples were also collected in Shannon and Carter counties in the southeast Missouri Ozarks to determine modern pollen rain. A 302-cm core retrieved from Buttonbush Bog has a basal data of 3,130 [+-] 100 yr B.P. and a date of 1,400 [+-] 100 yr B.P. at 52--56 cm. The Buttonbush Bog pollen sequence is divided into threemore » pollen-assemblage zones. The pollen spectra from Buttonbush Bog indicate that pine did not become well established in the southeast Missouri Ozarks until after 3,100 yr B.P. Zone 1 (the oldest) represents a mixed oak forest with minor components of pine and hickory. In Zone 2, pine values increase, indicating a shift to a pine-oak forest. The pollen sequence from Round Spring Shelter is divided into two pollen-assemblage zones. The lower zone (Zone 1) suggests the presence of a pine-oak forest in the vicinity of Round Spring prior to an Ambrosia rise at the top of the sequence in Zone 2. Regional pollen rain and variation in the local pollen rain are reflected by modern pollen spectra extracted from the bryophytic polsters surface samples. In this area the average regional pollen rain is dominated by pine, oak, hickory, and Ambrosia. The data are consistent with the mosaic of pine-oak and oak-hickory-pine forests characteristic of this region.« less

Fagaceae tree species allocate higher fraction of nitrogen to photosynthetic apparatus than Leguminosae in Jianfengling tropical montane rain forest, China.

PubMed

Tang, Jingchao; Cheng, Ruimei; Shi, Zuomin; Xu, Gexi; Liu, Shirong; Centritto, Mauro

2018-01-01

Variation in photosynthetic-nitrogen use efficiency (PNUE) is generally affected by several factors such as leaf nitrogen allocation and leaf diffusional conductances to CO2, although it is still unclear which factors significantly affect PNUE in tropical montane rain forest trees. In this study, comparison of PNUE, photosynthetic capacity, leaf nitrogen allocation, and diffusional conductances to CO2 between five Fagaceae tree species and five Leguminosae tree species were analyzed in Jianfengling tropical montane rain forest, Hainan Island, China. The result showed that PNUE of Fagaceae was significantly higher than that of Leguminosae (+35.5%), attributed to lower leaf nitrogen content per area (Narea, -29.4%). The difference in nitrogen allocation was the main biochemical factor that influenced interspecific variation in PNUE of these tree species. Fagaceae species allocated a higher fraction of leaf nitrogen to the photosynthetic apparatus (PP, +43.8%), especially to Rubisco (PR, +50.0%) and bioenergetics (PB +33.3%) in comparison with Leguminosae species. Leaf mass per area (LMA) of Leguminosae species was lower than that of Fagaceae species (-15.4%). While there was no significant difference shown for mesophyll conductance (gm), Fagaceae tree species may have greater chloroplast to total leaf surface area ratios and that offset the action of thicker cell walls on gm. Furthermore, weak negative relationship between nitrogen allocation in cell walls and in Rubisco was found for Castanopsis hystrix, Cyclobalanopsis phanera and Cy. patelliformis, which might imply that nitrogen in the leaves was insufficient for both Rubisco and cell walls. In summary, our study concluded that higher PNUE might contribute to the dominance of most Fagaceae tree species in Jianfengling tropical montane rain forest.

One-year delayed effect of fog on malaria transmission: a time-series analysis in the rain forest area of Mengla County, south-west China

PubMed Central

Tian, Linwei; Bi, Yan; Ho, Suzanne C; Liu, Wenjie; Liang, Song; Goggins, William B; Chan, Emily YY; Zhou, Shuisen; Sung, Joseph JY

2008-01-01

Background Malaria is a major public health burden in the tropics with the potential to significantly increase in response to climate change. Analyses of data from the recent past can elucidate how short-term variations in weather factors affect malaria transmission. This study explored the impact of climate variability on the transmission of malaria in the tropical rain forest area of Mengla County, south-west China. Methods Ecological time-series analysis was performed on data collected between 1971 and 1999. Auto-regressive integrated moving average (ARIMA) models were used to evaluate the relationship between weather factors and malaria incidence. Results At the time scale of months, the predictors for malaria incidence included: minimum temperature, maximum temperature, and fog day frequency. The effect of minimum temperature on malaria incidence was greater in the cool months than in the hot months. The fog day frequency in October had a positive effect on malaria incidence in May of the following year. At the time scale of years, the annual fog day frequency was the only weather predictor of the annual incidence of malaria. Conclusion Fog day frequency was for the first time found to be a predictor of malaria incidence in a rain forest area. The one-year delayed effect of fog on malaria transmission may involve providing water input and maintaining aquatic breeding sites for mosquitoes in vulnerable times when there is little rainfall in the 6-month dry seasons. These findings should be considered in the prediction of future patterns of malaria for similar tropical rain forest areas worldwide. PMID:18565224

Throughfall Monitoring Of Old Growth, Second Growth, And Cleared Vegetation Plots On Prince of Wales Island, Alaska

NASA Astrophysics Data System (ADS)

Prussian, K. M.

2006-12-01

The density of forest canopy affects the amount of rain reaching the forest floor in forested environments of Southeast Alaska. Less throughfall occurs in the second growth sites than in the old growth site and greater throughfall occurs in the clear-cut sites. More specifically, preliminary data show that SG sites received between 38 and 87% of the OG throughfall and the clear-cut sites experienced between 145 and 248% of the OG throughfall. Precipitation gages were used to monitor throughfall in each of the forested vegetation sites on Prince of Wales Island, Alaska, as an indicator of the amount of water reaching the forest floor in these different forest types. Data collected during 2004 and 2005 included 23 storms ranging from 0.2 to 10.6 inches of rain in the clear-cut forest. This monitoring is an effort to determine the affect, if any, that forest management could have on throughfall, and furthermore, lend information to forest management effects on the water balance within a watershed. Site selection focused on similarities in location, elevation, aspect, and accessibility while accounting for the three varying vegetation conditions. Data collected during 2004 and 2005 sampling seasons were in the same sampling plots, while data collected in 2006 is a duplicate set of sites. Twenty-three storms were used to determine the affect, if any, that forest management could have on throughfall, and furthermore, lend information to forest management effects on the water balance within a watershed. The second growth stand was harvested in 1979 and is currently in stem re-initiation phase with thick conifer regeneration. The clear-cut site was harvested in 1999 and contains conifer vegetation, blueberry, and salmonberry vegetation less than five feet in height. Storms were defined as events that were clearly delineated by lack of rainfall for a period of time, or similar antecedent conditions, and totaled at least .2 inches of rain at the CC site. Analysis of a storm event began prior to rainfall (in the CC site) and terminated post throughfall in the SG sites.

Off-nadir antenna bias correction using Amazon rain sigma(0) data

NASA Technical Reports Server (NTRS)

Birrer, I. J.; Dome, G. J.; Sweet, J.; Berthold, G.; Moore, R. K.

1982-01-01

The radar response from the Amazon rain forest was studied to determine the suitability of this region for use as a standard target to calibrate a scatterometer like that proposed for the National Oceanic Satellite System (NOSS). Backscattering observations made by the SEASAT Scatterometer System (SASS) showed the Amazon rain forest to be a homogeneous, azimuthally-isotropic, radar target which was insensitive to polarization. The variation with angle of incidence was adequately modeled as scattering coefficient (dB) = a theta b with typical values for the incidence-angle coefficient from 0.07 to 0.15 dB/deg. A small diurnal effect occurs, with measurements at sunrise being 0.5 dB to 1 dB higher than the rest of the day. Maximum-likelihood estimation algorithms presented here permit determination of relative bias and true pointing angle for each beam. Specific implementation of these algorithms for the proposed NOSS scatterometer system is also discussed.

Understory plant development in artificial canopy gaps in an 81-year-old forest stand on Chichagof Island, southeast Alaska

Treesearch

Scott Harris; Jeffrey Barnard

2017-01-01

This study assesses the understory plant response and associated effects on forage resources available to Sitka black-tailed deer (Odocoileus hemionus sitkensis), to the creation of artificial canopy gaps in a young-growth forest stand in the coastal temperate rain forest of southeast Alaska. The forest stand was approximately 58 years old when gaps were created and...

Global Physiographic and Climatic Maps to Support Revision of Environmental Testing Guidelines

DTIC Science & Technology

2009-07-06

precipitation and boarded by High and Low Relief Mountains or Interior Plains and Plateaus, such as the Amazon River Basin in South America and the Congo...taxonomy system. These form in hot climates with continual moisture availability, typically thought to occur only beneath tropical rainforests , though...Montane Tropical Forest Tropical Degraded Forest Seasonal Tropical Forest Rain Green Tropical Forest Tropical Rainforest FIGURE 6-1 DATE: 6-02

Roosevelt elk selection of temperate rain forest seral stages in western Washington

USGS Publications Warehouse

Schroer, Greg L.; Jenkins, Kurt J.; Moorhead, Bruce B.

1993-01-01

We studied habitat selection by Roosevelt elk (Cervus elaphus roosevelti) in a temperate rain forest in the lower Queets River Valley of the western Olympic Peninsula, Washington from June 1986-July 1987. Elk annual home ranges included predominantly unlogged forests protected within Olympic National Park and logged, regenerating forests adjacent to the park. Radio-collared elk selected valley floors during all seasons except winter, when elk frequently used an adjoining plateau 60 m above the floodplain. In winder, radio-collared elk selected 6-15 year-old clearcuts, which were available on the plateau. Elk selected mature deciduous forests of the valley floor during spring, summer, and autumn, and generally they selected old-age Sitka spruce forests during autumn and winter. Young clearcuts (1-5 years old) and even-aged, regenerating stands (16-150 years old) generally were avoided during all seasons. Management practices that retain preferred habitat of elk, such as deciduous forests, 6-15 yr-old coniferous stands, and old-age coniferous bottomland forests will benefit elk, particularly on elk ranges managed for short-rotation, even-aged stands. Silvicultural alternatives to typical even-aged stand management, such as uneven-aged management and commercial thinning, should also be considered for improving and maintaining interspersion of forage and cover.

Seed rain dynamics following disturbance exclusion in a secondary tropical dry forest in Morelos, Mexico.

PubMed

Ceccon, Eliane; Hernández, Patricia

2009-01-01

In most of the legally protected areas in Mexico local inhabitants use natural resources, such as fire wood or cattle grazing. These frequent but low-intensity disturbances have consequences at various levels of the tropical ecosystems and strongly impact forest structure and its regeneration capacity. Despite their importance, the effects of these perturbations in many aspects of tropical forest ecology and in the forest's capacity to recover after disturbance exclusion remain poorly understood. Understanding the impact of these processes on tropical forests is necessary for rehabilitating these forests and enhancing their productivity. In this study, we evaluate the impact of twelve years of exclusion (E) of cattle grazing and fire wood extraction in the composition and dynamics of seed rain, and compare this assessment to a similar analysis in an area where these perturbations continued (without exclusion, WE). We found a strong seasonality in seed rain (96% of seeds fell in the dry season) in both areas. There were no significant differences between E and WE sites in relation to overall seed density, species richness and diversity. However, the distribution along the year of seed species density was significantly different among the E and WE sites. The Jaccard's similarity index between E and WE sites was relatively low (0.57). Barochory was the most common dispersal mode observed among the 23 species in terms of seed species density (48%), followed by anemochory (39%) and zoochory (13%). In relation to seed density, anemochory was the most frequent dispersal mode (88%). Most species in the zone were categorized as small seeds (92%), and there were no significant differences in the distribution of seed size between E and WE. The spatial pattern of dispersal of the four species with the highest relative importance value index, in both areas, was aggregated. Twelve years of disturbance exclusion were not enough to fully restore the seed rain of the area; some differences were already perceptible after this lapse. On the other hand, zoochorous species were almost absent from both sites. The re-introduction of climax and animal-dispersed species may be, in addition to perturbation exclusion, a viable strategy to accelerate ecological restoration in this area.

Ge/Si Ratios Record the Impact of Forest Conversion to Cropland on Soil Chemical Weathering Processes and Solutes Export to Rivers

NASA Astrophysics Data System (ADS)

Ameijeiras-Marino, Y.; Opfergelt, S.; Derry, L. A.; Robinet, J.; Delmelle, P.

2016-12-01

Soil weathering processes influence solute fluxes to rivers, playing a major role in global biogeochemical cycles. Land use change such as forest conversion to cropland enhances soil erosion, which mobilizes solutes and exposes new mineral surfaces to weathering processes, changing soil weathering degree. However, the impact of forest conversion to cropland on soil weathering degree and solute fluxes exported from soils to rivers remain poorly quantified. This study assesses the soil weathering degree and uses a geochemical tracer of weathering, Ge/Si ratio, to provide new insights on the impact of soil weathering processes under anthropogenic forcing on the transfer of solutes to rivers. A subtropical site was studied in Rio Grande do Sul (Brazil). This area is characterized by mean annual rainfall of 1800 mm, with strong rain events mobilizing high sediment load. A forested catchment is considered as the reference and compared to a catchment cultivated for the past 100 years (similar lithology and climate). Bedrock, soil, soil pore water and stream water (during base flow and rain events) samples were analysed for their chemical and mineralogical compositions and Ge/Si ratios (combined isotope dilution, HR-ICP-MS and hydride generation). Chemical and mineralogical analyses highlight that forest conversion to cropland decreases the soil weathering degree on steep slopes. Ge/Si ratios (μmol/mol) are comparable in bulk soils between the forested (2.33 ± 0.50) and the cultivated catchment (2.61 ± 0.62), but differ in soil pore waters between forest (0.47 ± 0.16) and culture (0.73 ± 0.15) indicating differences on soil weathering processes. The response of Ge/Si ratios in stream waters to a rain event differs between forest and culture, highlighting a larger contribution from soil pore waters to stream waters under culture. Altogether, our data support that land use history has an impact on the present day soil weathering processes and on the solute export to rivers.

Movement trajectories and habitat partitioning of small mammals in logged and unlogged rain forests on Borneo.

PubMed

Wells, Konstans; Pfeiffer, Martin; Lakim, Maklarin B; Kalko, Elisabeth K V

2006-09-01

1. Non-volant animals in tropical rain forests differ in their ability to exploit the habitat above the forest floor and also in their response to habitat variability. It is predicted that specific movement trajectories are determined both by intrinsic factors such as ecological specialization, morphology and body size and by structural features of the surrounding habitat such as undergrowth and availability of supportive structures. 2. We applied spool-and-line tracking in order to describe movement trajectories and habitat segregation of eight species of small mammals from an assemblage of Muridae, Tupaiidae and Sciuridae in the rain forest of Borneo where we followed a total of 13,525 m path. We also analysed specific changes in the movement patterns of the small mammals in relation to habitat stratification between logged and unlogged forests. Variables related to climbing activity of the tracked species as well as the supportive structures of the vegetation and undergrowth density were measured along their tracks. 3. Movement patterns of the small mammals differed significantly between species. Most similarities were found in congeneric species that converged strongly in body size and morphology. All species were affected in their movement patterns by the altered forest structure in logged forests with most differences found in Leopoldamys sabanus. However, the large proportions of short step lengths found in all species for both forest types and similar path tortuosity suggest that the main movement strategies of the small mammals were not influenced by logging but comprised generally a response to the heterogeneous habitat as opposed to random movement strategies predicted for homogeneous environments. 4. Overall shifts in microhabitat use showed no coherent trend among species. Multivariate (principal component) analysis revealed contrasting trends for convergent species, in particular for Maxomys rajah and M. surifer as well as for Tupaia longipes and T. tana, suggesting that each species was uniquely affected in its movement trajectories by a multiple set of environmental and intrinsic features.

Millennial-Scale ITCZ Variability in the Tropical Atlantic and Dynamics of Amazonian Rain Forest

NASA Astrophysics Data System (ADS)

Wang, X.; Auler, A. S.; Edwards, R. L.; Cheng, H.; Shen, C.; Smart, P. L.; Richards, D. A.

2003-12-01

Precipitation in the Amazon Basin is largely related to the intertropical convergence zone (ITCZ) in the tropical Atlantic which undergoes a regular seasonal migration. We chose a site south of the present day rainforest in semiarid northeastern Brazil, in order to study the timing of pluvial periods when the southern extend of the ITCZ would have been much further south than today. Shifts in the ITCZ position may have influenced the dynamics of rain forest and species diversity. We collected speleothems from northern Bahia state, located southeast of Amazonia. Age determinations with U-series dating methods show that samples grew rapidly during relatively short intervals (several hundreds of years) of glacial periods in the last 210 kyr. In addition, paleopluvial phases delineated by speleothem growth intervals show millennial-scale variations. Pluvial phases coincide with the timing of weak East Asian summer monsoon intensities (Wang et al., 2001, Science 294: 2345-2348), which have been correlated to the timing of stadials in Greenland ice core records and Heinrich events (Bond and Lotti, 1995, Science 267: 1005-1010). Furthermore, these intervals correspond to the periods of light color reflectance of Cariaco Basin sediments from ODP Hole 1002C (Peterson et al., 2000, Science, 290: 1947-1951), which was suggested to be caused by a southward shift of the northernmost position of the ITCZ and decreased rainfall in this region. Abrupt precipitation changes in northeastern Brazil may be due to the southward displacement of the southernmost position of the ITCZ associated with atmosphere-ocean circulation changes caused by (1) an increase in northern high latitude-tropical temperature gradient (Chiang et al., 2003, Paleoceanography, in press), and/or (2) the bipolar seesaw mechanism (Broecker et al., 1998, Paleoceanography 13: 119-121) during these Heinrich events. Pluvial phases are also coincident with higher insolation at 10° S during austral autumn. This association implies that insolation may contribute to the southward shift of the ITCZ and enhanced precipitation in northeastern Brazil. The mean latitudinal migration of the ITCZ in the tropical Atlantic may force Amazon rain forest dynamics. Fossils and geomorphologic evidence found nearby indicate much wetter climates and possible tropical rainforest expansion to this locality in the past (Auler and Smart, 2001, Quaternary Research 55: 159-167). Furthermore, low δ 13C (around -11‰ ) values in speleothems suggest an extensive C3 forest coverage, different from current drought-resistant caatinga vegetation. During time of high rainfall, northeastern Brazil may act as a migration corridor between two species-rich communities, the Amazon Rain Forest and the Atlantic Rain Forest.

Feeding group responses of a Neotropical termite assemblage to rain forest fragmentation.

PubMed

Davies, Richard G

2002-10-01

Biomass collapse and its associated microclimatic stresses within recently isolated rain forest fragments may negatively affect species diversity of most resident taxa. However, for some decomposer organisms, increased resource availability via accompanying tree die-off may effect positive responses, at least for a time, with implications for rates of nutrient cycling and greenhouse gas release. This study investigates the early effects of forest fragmentation on a Neotropical termite assemblage. Numbers of encounters (surrogate for relative abundance) and species richness of wood and leaf-litter feeders, soil feeders, and the whole assemblage, were studied across true forest islands and mainland sites at a hydroelectric reservoir in French Guiana. Results showed no overall effect of fragmentation on either total termite encounters or species richness. However, numbers of encounters and species richness of wood and leaf-litter feeders showed positive responses to forest fragmentation. By contrast, soil feeders showed a negative response for numbers of encounters and no significant effect for species richness. Environmental data suggest that increased tree die-off, and other edge effects associated with biomass collapse, were underway at the time of sampling. Resulting increase in resource availability may therefore explain the positive influence on wood and leaf-litter feeders. A possible decrease in predation pressure from ants with decrease in island size was not tested for, but was a likely effect of the flooded matrix habitat. Fragmentation effects on soil feeder encounters may be due to the energetic and microclimatic constraints of feeding lower down the humification gradient of termite food substrates, but were not sufficient to affect species richness. The patterns revealed suggest that rates of wood decomposition following tree die-off, and of soil nutrient cycling, under different rain forest fragmentation scenarios, merit further study.

Production of Alkaline Cellulase by Fungi Isolated from an Undisturbed Rain Forest of Peru

PubMed Central

Vega, Karin; Villena, Gretty K.; Sarmiento, Victor H.; Ludeña, Yvette; Vera, Nadia; Gutiérrez-Correa, Marcel

2012-01-01

Alkaline cellulase producing fungi were isolated from soils of an undisturbed rain forest of Peru. The soil dilution plate method was used for the enumeration and isolation of fast growing cellulolytic fungi on an enriched selective medium. Eleven out of 50 different morphological colonies were finally selected by using the plate clearing assay with CMC as substrate at different pH values. All 11 strains produced cellulases in liquid culture with activities at alkaline pH values without an apparent decrease of them indicating that they are true alkaline cellulase producers. Aspergillus sp. LM-HP32, Penicillium sp. LM-HP33, and Penicillium sp. LM-HP37 were the best producers of FP cellulase (>3 U mL−1) with higher specific productivities (>30 U g−1 h−1). Three strains have been found suitable for developing processes for alkaline cellulase production. Soils from Amazonian rain forests are good sources of industrial fungi with particular characteristics. The results of the present study are of commercial and biological interest. Alkaline cellulases may be used in the polishing and washing of denim processing of the textile industry. PMID:23213539

Foreign petroleum companies developing new paradigm for operating in rain forest region

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

Williams, B.

1997-04-21

Multinational petroleum companies working in South America are gradually sculpting a new paradigm of how to operate in a rain forest with utmost regard for its indigenous people and environmental resources. This new paradigm can serve as a litmus test for the future of oil and gas operations in the rain forest--not only for South America, but for other such jungle settings around the world. And the lessons learned here can readily be adopted as standard operating procedures for projects involving other environments and communities, from the natives of arctic deserts to the mean streets of the urban poor. Thismore » is more than a new wrinkle in public relations for an oil and gas company. What`s involved is a need for a company to recognize that it must move beyond compliance on laws and permits and regulations into the next stage: a top-to-bottom commitment to partnership with all the stakeholders in a project, not just the companies themselves and the respective government with ownership of hydrocarbon resources. The paper discusses the changing focus, industry`s traditional responses, new strategy, ARCO`s plan, self-sufficient, and what`s at stake.« less

Rain rate and modeled fade distributions at 20 GHz and 30 GHz derived from five years of network rain gauge measurements

NASA Technical Reports Server (NTRS)

Goldhirsh, Julius; Krichevsky, Vladimir; Gebo, Norman

1992-01-01

Five years of rain rate and modeled slant path attenuation distributions at 20 GHz and 30 GHz derived from a network of 10 tipping bucket rain gages was examined. The rain gage network is located within a grid 70 km north-south and 47 km east-west in the Mid-Atlantic coast of the United States in the vicinity of Wallops Island, Virginia. Distributions were derived from the variable integration time data and from one minute averages. It was demonstrated that for realistic fade margins, the variable integration time results are adequate to estimate slant path attenuations at frequencies above 20 GHz using models which require one minute averages. An accurate empirical formula was developed to convert the variable integration time rain rates to one minute averages. Fade distributions at 20 GHz and 30 GHz were derived employing Crane's Global model because it was demonstrated to exhibit excellent accuracy with measured COMSTAR fades at 28.56 GHz.

Influence of understory cover on soil water and evaporation fluxes: a trial

NASA Astrophysics Data System (ADS)

Jiménez-Rodríguez, César; Magdalena Warter, Maria; Coenders-Gerrits, Miriam

2017-04-01

Within a forest ecosystem the litter layer is an important hydrological component and contributes towards the water and energy exchange between the sub-canopy and the soil. Evaporation within a forest is made up of different fractions coming from the dry soil, vegetation and litter layers. The quantification and partitioning of each fraction remains difficult as there is hard to estimate correctly the amount of water moved by evaporation or percolation at ecosystem level. With the aim to determine the influence of forest understory on the evaporation fluxes, four ground cover types were selected from the Speulderbos forest in the Netherlands. The mosses species of "Thamariskmoss" (Thuidium thamariscinum), "Rough Stalked Feathermoss" (Brachythecium rutabulum), and "Haircapmoss" (Polytrichum commune) were compared with a litter layer made up of Douglas-Fir needles (Pseudotsuga menziesii). Four PVC basins with 40cm x 60cm were filled with forest soil and sheltered with the selected ground covers. Each box was equipped with a soil moisture sensor, and a set Temperature and Relative Humidity sensors to determine the VPD during the study period. The study period lasts 4 weeks, while the percolation rates were measured in a daily basis. The rainfall events were simulated in the lab, applying the same rain event to each box at the same time. A total amount of 43.12 mm of rain were added to the boxes during the 4 weeks of the experiment, and distributed in 11 rain events which differ in amount and timing between events. The percolation in all the boxes was more than the 50% of the rain events due to the sandy condition of the soil, while the evaporation rates were affected not only by the room atmospheric conditions, but for the cover type present in each box. Except for the Polytrichum moss, a moss known for its water conducting abilities, all cover types showed a decline before and increase after a rain event. This species showed a steady increase in soil water content over the sampling period due to keeping the water longer in the surface. The evaporation was driven partly by the temperature in the room, while the structural characteristics of the mosses allow the differences in evaporation rates showed along the study period.

Tree seed rain and seed removal, but not the seed bank, impede forest recovery in bracken (Pteridium aquilinum (L.) Kuhn)-dominated clearings in the African highlands.

PubMed

Ssali, Fredrick; Moe, Stein R; Sheil, Douglas

2018-04-01

Considerable areas dominated by bracken Pteridium aquilinum (L.) Kuhn occur worldwide and are associated with arrested forest recovery. How forest recovery is impeded in these areas remains poorly understood, especially in the African highlands. The component processes that can lead to recruitment limitation-including low seed arrival, availability and persistence-are important determinants of plant communities and offer a potential explanation for bracken persistence. We investigated key processes that can contribute to recruitment limitation in bracken-dominated clearings in the Bwindi Impenetrable National Park, Uganda. We examined if differences in seed rain (dispersal limitation), soil seed bank, or seed removal (seed viability and persistence) can, individually or in combination, explain the differences in tree regeneration found between bracken-dominated areas and the neighboring forest. These processes were assessed along ten 50-m transects crossing the forest-bracken boundary. When compared to the neighboring forest, bracken clearings had fewer seedlings (bracken 11,557 ± 5482 vs. forest 34,515 ± 6066 seedlings/ha), lower seed rain (949 ± 582 vs. 1605 ± 335 tree seeds m -2  year -1 ), comparable but sparse soil seed bank (304 ± 236 vs. 264 ± 99 viable tree seeds/m 2 ), higher seed removal (70.1% ± 2.4% vs. 40.6% ± 2.4% over a 3-day interval), and markedly higher rodent densities (25.7 ± 5.4 vs. 5.0 ± 1.6 rodents per 100 trapping sessions). Camera traps revealed that rodents were the dominant animals visiting the seeds in our seed removal study. Synthesis : Recruitment limitation contributes to both the slow recovery of forest in bracken-dominated areas, and to the composition of the tree species that occur. Low seed arrival and low persistence of unburied seeds can both explain the reduced density of seedlings found in bracken versus neighboring forest. Seed removal, likely due to rodents, in particular appears sufficient to constrain forest recovery and impacts some species more severely than others.

Soil-water relations of shallow forested soils during flash floods in West Virginia

Treesearch

James H. Patric

1981-01-01

On May 24, 1978, heavy rain caused flash flooding on densely forested land near Parsons, in Tucker County, West Virginia. Poststorm evidences of soil and water behavior were examined in detail on soils related to the Dekalb and Leetonia series. Other flash floods struck seven forested sections of the state in August. Less detailed observation after these storms...

H.T. Odum and the Luquillo Experimental Forest

Treesearch

Ariel E. Lugo

2004-01-01

How does the forest operate, develop its patterns, retain information in its memory sites, and transmit the great message to the future? (Odum, 1970a, p. x) The rain forest achieves complexity, high metabolism, and stability over geological time periods without surges and waste. Can we find in this example the clues for designing our own equally effective systems of...

1954 forest fire weather in western Oregon and Washington.

Treesearch

Owen P. Cramer

1954-01-01

For the second successive fire season forest fire weather in western Oregon and Washington was far below normal severity. The low danger is reflected in record low numbers of fires reported by forestry offices of both States and by the U. S. Forest Service for their respective protection areas. Although spring and fall fire weather was near normal, a rain-producing...

Basal area growth for 15 tropical tree species in Puerto Rico

Treesearch

Bernard R. Parresol

1995-01-01

The tabonuco forests of Puerto Rico support a diverse population of tree species valued for timber, fuel, food, wildlife food and cover, and erosion control among other uses. Tree basal area growth data spanning 39 years are available on 15 species from eight permanent plots in the Luquillo Experimental Forest. The complexity of the rain forest challenges current...

Repelling invaders: Hawaiian foresters use ecology to counter invasive species

Treesearch

Jim Kling; Julie Featured: Denslow; Tracy Johnson; Susan Cordell

2008-01-01

The Hawaiian Islands are one of the United States' most treasured natural resources. Their natural beauty attracts legions of visitors every year, and they represent a unique set of ecosystems. Despite their limited geographic size, Hawai‘i hosts a remarkable range of habitats. On some islands, dry tropical forest, wet rain forest, and alpine ecosystems are found...

Aerosol emissions by tropical forest and savanna biomass burning: Characteristic trace elements and fluxes

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

Echalar, F.; Gaudichet, A.; Cachier, H.

1995-11-15

This report characterizes and compares trace element emissions from fires of three different types of savannas and from the southwestern amazonian rain forest. This study tries to verify a fingerprint that may characterize savanna fires or tropical biomass burning.

Avian studies and research opportunities in the Luquillo Experimental Forest: a tropical rain forest in Puerto Rico

Treesearch

Joseph Wunderle, Jr; Wayne J. Arendt

2011-01-01

The Luquillo Experimental Forest (LEF) located on the Caribbean island of Puerto Rico has a rich history of ecological research, including a variety of avian studies, and is one of the most active ecological research sites in the Neotropics. The LEF spans an elevational range from 100 to 1075mover which five life zones and four forest types are found in a warm, humid...

Comparing the sustainability of different action policy possibilities: application to the issue of both household survival and forest preservation in the corridor of Fianarantsoa.

PubMed

Bernard, C; Martin, S

2013-10-01

A sustainability issue for the rain forest in the corridor of Fianarantsoa (Madagascar) is to preserve the forest while ensuring the development of the local population. The aim of this paper is to determine whether the current situation is sustainable or not according to different action policy possibilities. We propose a general procedure based on viability analysis: Translation of sustainability issues into constraints on the system state; elaboration of a mathematical model of system evolution rules in the form of controlled dynamical system; computations of the viability kernels according to different action policy possibilities. Among control variables, we focus on monetary transfer. Without monetary transfer, we show that the current situation of the rain forest corridor is not sustainable in our mathematical modeling framework. We then estimate the minimal maximal amount per year necessary to make the current situation sustainable. Copyright © 2013 Elsevier Inc. All rights reserved.

Performance analysis of rain attenuation on earth-to-satellite microwave links design in Libya

NASA Astrophysics Data System (ADS)

Rafiqul Islam, Md; Hussein Budalal, Asma Ali; Habaebi, Mohamed H.; Badron, Khairayu; Fadzil Ismail, Ahmad

2017-11-01

Performances of earth-to-satellite microwave links operating in Ku, Ka, and V-bands are degraded by the environment and strongly attenuated by rain. Rain attenuation is the most significant consideration and challenge to design a reliable earth-to-satellite microwave links for these frequency bands. Hence, it is essential for satellite link designer to take into account rain fade margin accurately before system implementation. Rain rate is the main measured parameter to predict of rain attenuation. Rainfall statistical data measured and recorded in Libya for the period of 30 years are collected from 5 locations. The prediction methods require one minute integration time rain intensity. Therefore, collected data were analyzed and processed to convert into one-minute rain rate cumulative distribution in Libya. The model proposed by ITU-R is used to predict and investigate rain fade based on converted 1-minute rain rate data. Rain fade predicted at two locations are used for performance analysis in terms of link spectral efficiency and throughput. V-band downlink shows that 99.99% availability is possible in all the Southern part stations in Libya at 0.29 bps/Hz spectral efficiency and 20.74 Mbps throughput when 72 MHz transponder band width is used which is not feasible in Northern part. Results of this paper will be a very useful resource to design highly reliable earth-to-satellite communication links in Libya.

Characterization of tropical precipitation using drop size distribution and rain rate-radar reflectivity relation

NASA Astrophysics Data System (ADS)

Das, Saurabh; Maitra, Animesh

2018-04-01

Characterization of precipitation is important for proper interpretation of rain information from remotely sensed data. Rain attenuation and radar reflectivity (Z) depend directly on the drop size distribution (DSD). The relation between radar reflectivity/rain attenuation and rain rate (R) varies widely depending upon the origin, topography, and drop evolution mechanism and needs further understanding of the precipitation characteristics. The present work utilizes 2 years of concurrent measurements of DSD using a ground-based disdrometer at five diverse climatic conditions in Indian subcontinent and explores the possibility of rain classification based on microphysical characteristics of precipitation. It is observed that both gamma and lognormal distributions are performing almost similar for Indian region with a marginally better performance by one model than other depending upon the locations. It has also been found that shape-slope relationship of gamma distribution can be a good indicator of rain type. The Z-R relation, Z = ARb, is found to vary widely for different precipitation systems, with convective rain that has higher values of A than the stratiform rain for two locations, whereas the reverse is observed for the rest of the three locations. Further, the results indicate that the majority of rainfall (>50%) in Indian region is due to the convective rain although the occurrence time of convective rain is low (<10%).

Towards ground-truthing of spaceborne estimates of above-ground life biomass and leaf area index in tropical rain forests

NASA Astrophysics Data System (ADS)

Köhler, P.; Huth, A.

2010-08-01

The canopy height h of forests is a key variable which can be obtained using air- or spaceborne remote sensing techniques such as radar interferometry or LIDAR. If new allometric relationships between canopy height and the biomass stored in the vegetation can be established this would offer the possibility for a global monitoring of the above-ground carbon content on land. In the absence of adequate field data we use simulation results of a tropical rain forest growth model to propose what degree of information might be generated from canopy height and thus to enable ground-truthing of potential future satellite observations. We here analyse the correlation between canopy height in a tropical rain forest with other structural characteristics, such as above-ground life biomass (AGB) (and thus carbon content of vegetation) and leaf area index (LAI) and identify how correlation and uncertainty vary for two different spatial scales. The process-based forest growth model FORMIND2.0 was applied to simulate (a) undisturbed forest growth and (b) a wide range of possible disturbance regimes typically for local tree logging conditions for a tropical rain forest site on Borneo (Sabah, Malaysia) in South-East Asia. In both undisturbed and disturbed forests AGB can be expressed as a power-law function of canopy height h (AGB = a · hb) with an r2 ~ 60% if data are analysed in a spatial resolution of 20 m × 20 m (0.04 ha, also called plot size). The correlation coefficient of the regression is becoming significant better in the disturbed forest sites (r2 = 91%) if data are analysed hectare wide. There seems to exist no functional dependency between LAI and canopy height, but there is also a linear correlation (r2 ~ 60%) between AGB and the area fraction of gaps in which the canopy is highly disturbed. A reasonable agreement of our results with observations is obtained from a comparison of the simulations with permanent sampling plot (PSP) data from the same region and with the large-scale forest inventory in Lambir. We conclude that the spaceborne remote sensing techniques such as LIDAR and radar interferometry have the potential to quantify the carbon contained in the vegetation, although this calculation contains due to the heterogeneity of the forest landscape structural uncertainties which restrict future applications to spatial averages of about one hectare in size. The uncertainties in AGB for a given canopy height are here 20-40% (95% confidence level) corresponding to a standard deviation of less than ± 10%. This uncertainty on the 1 ha-scale is much smaller than in the analysis of 0.04 ha-scale data. At this small scale (0.04 ha) AGB can only be calculated out of canopy height with an uncertainty which is at least of the magnitude of the signal itself due to the natural spatial heterogeneity of these forests.

Biogenic emissions and biomass burning influences on the chemistry of the fogwater and stratiform precipitations in the African equatorial forest

NASA Astrophysics Data System (ADS)

Lacaux, J. P.; Loemba-Ndembi, J.; Lefeivre, B.; Cros, B.; Delmas, R.

An automatic wet-only precipitation collector and a fogwater collector were operated in the coastal forest of equatorial Congo (Dimonika), for a complete seasonal cycle (November 1986-September 1987). Inorganic (Na +, K +, NH 4+, Ca 2+, NO 3-, Cl -, SO 42-) and organic (HCOO -, CH 3COO -) ions were determined in 33 stratiform rain events and nine fog events. With the raindrop size distributions, measured over a 1 year period (June 1988-June 1989) at the site of Enyelé in the Equatorial forest of Congo, were established the relationship between the liquid water content ( LWC in gm -3) and the rate of rainfall ( R in mm h -1) for the stratiform rains: LWC = 0.055 × R0.871 with a correlation coefficient of 0.98. Taking into account the dilution effect due to LWC, ionic concentrations of fogwater and stratiform precipitation are enriched during the dry season. In particular, K +, NO 3-, SO 42- and Ca 2+ are considerably enriched indicating the seasonal influence of the biomass burning due to savanna fires and terrigenous source from deserts of the Southern Hemisphere. Comparison of the chemical contents of fogwater—which mainly represents the local emission of the forest—and stratiform precipitation—which represent the air chemical content of the planetary boundary layer—during the dry season enabled us to show the following. Fog and rain with comparable chemical contents in mineral elements indicate a generalized contamination of the boundary layer by marine (Na +, Cl -), terrigenous (Ca 2+) and above all by biomass burning (K +, NO 3-, SO 42-) sources. The organic content (HCOO -, CH 3COO -) higher for the fogs than for rains, unexplainable by the dilution effect, has its source at a local level in the forest ecosystem. The estimation, from the organic content of fog and rain, of the gaseous concentrations of formic and acetic acids confirm the production of carboxylic acids measured in Amazonia during ABLE (for HCOOH : 510 ppt at canopy level and 170 ppt in free troposphere and for CH 3COOH : 410 ppt and 210 ppt, respectively).

Impacts of acid precipitation on coniferous forest ecosystems

Treesearch

Gunnar Abrahamsen; Richard Horntvedt; Bjorn Tveite

1976-01-01

This paper summarizes the results from current studies in Norway. One main approach is the application of artificial acid "rain" and of lime to field plots and lysimeters. Application during two growth seasons of 50 mm per month of "rain water" of pH 3 to a podzol soil increased the acidity of the humus and decreased the base saturation. The...

Multitrophic effects of calcium availability on invasive alien plants, birds, and bird prey items

Treesearch

Vince D' Amico; Greg Shriver; Jake Bowman; Meg Ballard; Whitney Wiest; Liz Tymkiw; Melissa Miller

2011-01-01

Acid rain alters forest soil calcium concentrations in two ways: (1) hydrogen ions displace exchangeable calcium adsorbed to soil surfaces, and (2) aluminum is released to soil water by acid rain and displaces adsorbed calcium. This increases the absorption of aluminum by plant roots, and decreases the absorption of calcium, causing calcium to be more readily leached...

Acid Rain Effects on Adirondack Streams - Results from the 2003-05 Western Adirondack Stream Survey (the WASS Project)

USGS Publications Warehouse

Lawrence, Gregory B.; Roy, Karen M.; Baldigo, Barry P.; Simonin, Howard A.; Passy, Sophia I.; Bode, Robert W.; Capone, Susan B.

2009-01-01

Traditionally lakes have been the focus of acid rain assessments in the Adirondack region of New York. However, there is a growing recognition of the importance of streams as environmental indicators. Streams, like lakes, also provide important aquatic habitat, but streams more closely reflect acid rain effects on soils and forests and are more prone to acidification than lakes. Therefore, a large-scale assessment of streams was undertaken in the drainage basins of the Oswegatchie and Black Rivers; an area of 4,585 km2 in the western Adirondack region where acid rain levels tend to be highest in New York State.

Temperate rain forest species partition fine-scale gradients in light availability based on their leaf mass per area (LMA)

PubMed Central

Fajardo, Alex; Siefert, Andrew

2016-01-01

Background and Aims Ecologists are increasingly using plant functional traits to predict community assembly, but few studies have linked functional traits to species’ responses to fine-scale resource gradients. In this study, it was tested whether saplings of woody species partition fine-scale gradients in light availability based on their leaf mass per area (LMA) in three temperate rain forests and one Mediterranean forest in southern Chile. Methods LMA was measured under field conditions of all woody species contained in approx. 60 plots of 2 m2 in each site, and light availability, computed as the gap light index (GLI), was determined. For each site, species’ pairwise differences in mean LMA (Δ LMA) and abundance-weighted mean GLI (Δ light response) of 2 m2 plots were calculated and it was tested whether they were positively related using Mantel tests, i.e. if species with different LMA values differed in their response to light availability. Additionally linear models were fitted to the relationship between plot-level mean LMA and GLI across plots for each site. Key Results A positive and significant relationship was found between species’ pairwise differences in mean LMA and differences in light response across species for all temperate rain forests, but not for the Mediterranean forest. The results also indicated a significant positive interspecific link between LMA and light availability for all forests. This is in contrast to what is traditionally reported and to expectations from the leaf economics spectrum. Conclusions In environments subjected to light limitation, interspecific differences in a leaf trait (LMA) can explain the fine-scale partitioning of light availability gradients by woody plant species. This niche partitioning potentially facilitates species coexistence at the within-community level. The high frequency of evergreen shade-intolerant species in these forests may explain the positive correlation between light availability and LMA. PMID:27604280

Litterfall production along successional and altitudinal gradients of subtropical monsoon evergreen broadleaved forests in Guangdong, China

USGS Publications Warehouse

Zhou, G.; Guan, L.; Wei, X.; Zhang, Dongxiao; Zhang, Q.; Yan, J.; Wen, D.; Liu, J.; Liu, S.; Huang, Z.; Kong, G.; Mo, J.; Yu, Q.

2007-01-01

Evaluation of litterfall production is important for understanding nutrient cycling, forest growth, successional pathways, and interactions with environmental variables in forest ecosystems. Litterfall was intensively studied during the period of 1982-2001 in two subtropical monsoon vegetation gradients in the Dinghushan Biosphere Reserve, Guangdong Province, China. The two gradients include: (1) a successional gradient composed of pine forest (PF), mixed pine and broadleaved forest (MF) and monsoon evergreen broadleaved forest (BF), and (2) an altitudinal gradient composed of Baiyunci ravine rain forest (BRF), Qingyunci ravine rain forest (QRF), BF and mountainous evergreen broadleaved forest (MMF). Mean annual litterfall production was 356, 861 and 849 g m-2 for PF, MF and BF of the successional gradient, and 1016, 1061, 849 and 489 g m-2 for BRF, QRF, BF and MMF of the altitudinal gradient, respectively. As expected, mean annual litterfall of the pioneer forest PF was the lowest, but rapidly increased over the observation period while those in other forests were relatively stable, confirming that forest litterfall production is closely related to successional stages and growth patterns. Leaf proportions of total litterfall in PF, MF, BF, BRF, QRF and MMF were 76.4%, 68.4%, 56.8%, 55.7%, 57.6% and 69.2%, respectively, which were consistent with the results from studies in other evergreen broadleaved forests. Our analysis on litterfall monthly distributions indicated that litterfall production was much higher during the period of April to September compared to other months for all studied forest types. Although there were significant impacts of some climate variables (maximum and effective temperatures) on litterfall production in some of the studied forests, the mechanisms of how climate factors (temperature and rainfall) interactively affect litterfall await further study. ?? 2006 Springer Science+Business Media B.V.

Ecological setting of the Wind River old-growth forest.

Treesearch

David C. Shaw; Jerry F. Franklin; Ken Bible; Jeffrey Klopatek; Elizabeth Freeman; Sarah Greene; Geoffrey G. Parker

2004-01-01

The Wind River old-growth forest, in the southern Cascade Range of Washington State, is a cool (average annual temperature, 8.7°C), moist (average annual precipitation, 2223 mm), 500-year-old Douglas-fir-western hemlock forest of moderate to low productivity at 371-m elevation on a less than 10% slope. There is a seasonal snowpack (November-March), and rain-on-snow and...

Community level analysis of opportunistically-breeding anurans in western Mexico

Treesearch

Paulette. L. Ford; J. Scott Norman

2006-01-01

Tropical dry forests are among the most seasonal habitats in the world. They are most common in hot lowlands outside the equatorial rain forest zone, where rainfall is more seasonal and the dry season is most pronounced, lasting for several weeks or months (Brown and Lomolino 1998). They are also some of the most threatened of the major tropical forest types, largely...

Come Rain or Shine: A Whole School Approach to Forest School

ERIC Educational Resources Information Center

Vandewalle, Martyn

2010-01-01

This article begins by describing a typical Forest School session that takes place in every class every week at The Wroxham School in Potters Bar. It goes on to outline a brief history of Forest School from its inception, its aims and ethos, and how it has been adapted for the ethos and needs of the children at Wroxham. The article also looks at…

Fog and soil weathering as sources of nutrients in a California redwood forest

Treesearch

Holly A. Ewing; Kathleen C. Weathers; Amanda M. Lindsey; Pamela H. Templer; Todd E. Dawson; Damon C. Bradbury; Mary K. Firestone; Vanessa K.S. Boukili

2012-01-01

Fog water deposition is thought to influence the ecological function of many coastal ecosystems, including coast redwood forests. We examined cation and anion inputs from fog and rain, as well as the fate of these inputs, within a Sonoma County, California, coast redwood forest to elucidate the availability of these ions and some of the biotic and abiotic processes...

Seedling and Sapling Dynamics of Treefall Pits in Puerto Rico1

Treesearch

Lawrence R. Walker

2000-01-01

Seedling and sapling dynamics in a Puerto Rican rain forest were compared between forest understory and soil pits created by the uprooting of 27 trees during Hurricane Hugo. Soil N and P, organic matter, and soil moisture were lower and bulk densities were higher in the disturbed mineral soils of the pits than in undisturbed forest soils ten months after the hurricane...

[Ecological regulation services of Hainan Island ecosystem and their valuation].

PubMed

Ouyang, Zhiyun; Zhao, Tongqian; Zhao, Jingzhu; Xiao, Han; Wang, Xiaoke

2004-08-01

Ecosystem services imply the natural environmental conditions on which human life relies for existence, and their effectiveness formed and sustained by ecosystem and its ecological processes. In newly research reports, they were divided into four groups, i. e., provisioning services, regulation services, cultural services, and supporting services. To assess and valuate ecosystem services is the foundation of regional environmental reserve and development. Taking Hainan Island as an example and based on the structure and processes of natural ecosystem, this paper discussed the proper methods for regulation services assessment. The ecosystems were classified into 13 types including valley rain forest, mountainous rain forest, tropical monsoon forest, mountainous coppice forest, mountainous evergreen forest, tropical coniferous forest, shrubs, plantation, timber forest, windbreak forest, mangrove, savanna, and cropland, and then, the regulation services and their economic values of Hainan Island ecosystem were assessed and evaluated by terms of water-holding, soil conservancy, nutrient cycle, C fixation, and windbreak function. The economic value of the regulation services of Hainan Island ecosystem was estimated as 2035.88 x 10(8)-2153.39 x 10(8) RMB yuan, 8 times higher to its provisioning services (wood and agricultural products) which were estimated as only 254.06 x 10(8) RMB yuan. The result implied that ecosystem regulation services played an even more important role in the sustainable development of society and economy in Hainan Island.

Multicriteria evaluation of simulated logging scenarios in a tropical rain forest.

PubMed

Huth, Andreas; Drechsler, Martin; Köhler, Peter

2004-07-01

Forest growth models are useful tools for investigating the long-term impacts of logging. In this paper, the results of the rain forest growth model FORMIND were assessed by a multicriteria decision analysis. The main processes covered by FORMIND include tree growth, mortality, regeneration and competition. Tree growth is calculated based on a carbon balance approach. Trees compete for light and space; dying large trees fall down and create gaps in the forest. Sixty-four different logging scenarios for an initially undisturbed forest stand at Deramakot (Malaysia) were simulated. The scenarios differ regarding the logging cycle, logging method, cutting limit and logging intensity. We characterise the impacts with four criteria describing the yield, canopy opening and changes in species composition. Multicriteria decision analysis was used for the first time to evaluate the scenarios and identify the efficient ones. Our results plainly show that reduced-impact logging scenarios are more 'efficient' than the others, since in these scenarios forest damage is minimised without significantly reducing yield. Nevertheless, there is a trade-off between yield and achieving a desired ecological state of logged forest; the ecological state of the logged forests can only be improved by reducing yields and enlarging the logging cycles. Our study also demonstrates that high cutting limits or low logging intensities cannot compensate for the high level of damage caused by conventional logging techniques.

Hyperparasitoid wasps (Hymenoptera: Trigonalidae) reared from dry forest and rain forest caterpillars of Area de Conservacion, Guanacaste, Costa Rica

USDA-ARS?s Scientific Manuscript database

Five species of Trigonalidae, hyperparasites of Ichneumonidae (Hymenoptera) and Tachinidae (Diptera) that parasitize caterpillars (Lepidoptera), have been reared during the ongoing caterpillar inventory of Area de Conservación Guanacaste (ACG), Guanacaste Province, northwestern Costa Rica: Lycogaste...

[Epiphytic communities of arboreal formations in Southern Vietnam: an analysis of species composition and synusias structure in dependence on the extent of anthropogenic impact].

PubMed

Es'kov, A K

2013-01-01

Species composition of epiphytic communities within different formations of Phú Quôc Island (Southern Vietnam) is studied. The dependence of species composition and structural complexity of epiphytic communities on formation quality is demonstrated. Representatives of different families differ notably in their sensitivity to disturbances. Most vulnerable are Orchidaceae which represent the dominant group in epiphytic community of rain forest and which drop out almost completely under anthropogenic impacts. In less disturbed forests, epiphyte species diversity increases mainly at the expense of "lower" synusias and directly depends on the formation layering. Diminishing of layering numbers leads to dropping out of species belonging to "lower" synusias. Among epiphytes, the indicators of disturbed communities can be detected, namely species of ruderal strategy (explerents). In primal rain forest, they are absent or barely noticeable. An index is proposed for estimation of epiphytic communitiy complexity.

Carbon monoxide and the burning earth

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

Newell, R.E.; Reichle, H.G. Jr.; Seiler, W.

1989-10-01

Carbon monoxide is one of many gases whose presence in the atmosphere is blamed largely on industrial activity in the Northern Hemisphere. Data collected by the authors show that the gas is also abundant in the Southern Hemisphere, where it comes mainly from the burning of tropical rain forests and savannas. The high levels of carbon monoxide confirm other evidence that the rain forests are being diminished rapidly, which may affect the climates of these regions as well as globally. Increases in carbon monoxide could also encourage the accumulation of pollutant gases such as ozone and methane. The first ismore » highly toxic to plants and the second would add to the greenhouse effect.« less

Spatial distribution by Canistropsis microps (E. Morren ex Mez) Leme (Bromeliaceae: Bromelioideae) in the Atlantic rain forest in Ilha Grande, Southeastern Brazil.

PubMed

Nunes-Freitas, A F; Rocha, C F D

2007-08-01

Canistropsis microps (Bromeliaceae: Bromelioideae) is an endemic species of Atlantic rain forest areas in Rio de Janeiro State, which are very abundant in not very disturbed forests in Ilha Grande, on the southern coast of the State. In this study, we analyzed the vertical and horizontal distribution patterns of the species in an area of rain forest with little evidence of disturbance at Vila Dois Rios, Ilha Grande, relating the patterns to sunlight in the microhabitat. We also identified the types of substrate used by the species and the rate of asexual reproduction. Canistropsis microps had high densities (estimated at 84,425 rosettes/ha), and has an aggregated distribution (Id = 2.86). About 80% of the rosettes were generated by clonal growth, whereas less than 20% were produced from seedlings. Most of the rosettes were found on straight tree trunks (DBH > 50 cm). There was a significant inverse correlation between the incidence of sunlight in the habitat and the abundance of individuals. Rosettes were found up to a maximum height of 9.5 m, but most occured between 1.5 and 5.5 m, where light varied from 25 to 50 micromol x s(-1) x m(-2). We conclude that vertical and horizontal distribution patterns in C. microps may be partially explained by the occurrence of appropriate substrate, an intensity of sunlight favorable to the development of the species and to a high rate of vegetative reproduction.

Organic carbon burial in a mangrove forest, margin and intertidal mud flat

NASA Astrophysics Data System (ADS)

Sanders, Christian J.; Smoak, Joseph M.; Naidu, A. Sathy; Sanders, Luciana M.; Patchineelam, Sambasiva R.

2010-12-01

The flux of total organic carbon (TOC) to depositional facies (intertidal mud flat, margin and forest) was quantified for a tropical mangrove forest in Brazil. Results indicate that these mangrove margins and intertidal mudflats are sites of large TOC accumulation, almost four times greater than the global averages for mangrove forests. The TOC burial rates were determined from organic carbon content in sediment cores which were dated using 210Pb. Burial rates were calculated to be 1129, 949, and 353 (g m -2 yr -1), for the mud flat, margin and forest, respectively. Sediment accumulation rates (SAR) were estimated to be 7.3, 5.0 and 2.8 mm yr -1. Sediment characterization (δ 13C, δ 15N, TOC/TN and mud fraction) indicated a representative mangrove system with a record of consistent organic matter flux of up to 100 years. Because of substantial burial of organic carbon in mangrove ecosystems, their role in the global carbon budget must be considered. More importantly, as climate change influences temperature and sea level, mangrove ecosystems will respond to specific climatic conditions.

Do little interactions get lost in dark random forests?

PubMed

Wright, Marvin N; Ziegler, Andreas; König, Inke R

2016-03-31

Random forests have often been claimed to uncover interaction effects. However, if and how interaction effects can be differentiated from marginal effects remains unclear. In extensive simulation studies, we investigate whether random forest variable importance measures capture or detect gene-gene interactions. With capturing interactions, we define the ability to identify a variable that acts through an interaction with another one, while detection is the ability to identify an interaction effect as such. Of the single importance measures, the Gini importance captured interaction effects in most of the simulated scenarios, however, they were masked by marginal effects in other variables. With the permutation importance, the proportion of captured interactions was lower in all cases. Pairwise importance measures performed about equal, with a slight advantage for the joint variable importance method. However, the overall fraction of detected interactions was low. In almost all scenarios the detection fraction in a model with only marginal effects was larger than in a model with an interaction effect only. Random forests are generally capable of capturing gene-gene interactions, but current variable importance measures are unable to detect them as interactions. In most of the cases, interactions are masked by marginal effects and interactions cannot be differentiated from marginal effects. Consequently, caution is warranted when claiming that random forests uncover interactions.

Effects of rainfall exclusion on leaf gas exchange traits and osmotic adjustment in mature canopy trees of Dryobalanops aromatica (Dipterocarpaceae) in a Malaysian tropical rain forest.

PubMed

Inoue, Yuta; Ichie, Tomoaki; Kenzo, Tanaka; Yoneyama, Aogu; Kumagai, Tomo'omi; Nakashizuka, Tohru

2017-10-01

Climate change exposes vegetation to unusual levels of drought, risking a decline in productivity and an increase in mortality. It still remains unclear how trees and forests respond to such unusual drought, particularly Southeast Asian tropical rain forests. To understand leaf ecophysiological responses of tropical rain forest trees to soil drying, a rainfall exclusion experiment was conducted on mature canopy trees of Dryobalanops aromatica Gaertn.f. (Dipterocarpaceae) for 4 months in an aseasonal tropical rain forest in Sarawak, Malaysia. The rainfall was intercepted by using a soft vinyl chloride sheet. We compared the three control and three treatment trees with respect to leaf water use at the top of the crown, including stomatal conductance (gsmax), photosynthesis (Amax), leaf water potential (predawn: Ψpre; midday: Ψmid), leaf water potential at turgor loss point (πtlp), osmotic potential at full turgor (π100) and a bulk modulus of elasticity (ε). Measurements were taken using tree-tower and canopy-crane systems. During the experiment, the treatment trees suffered drought stress without evidence of canopy dieback in comparison with the control trees; e.g., Ψpre and Ψmid decreased with soil drying. Minimum values of Ψmid in the treatment trees decreased during the experiment, and were lower than πtlp in the control trees. However, the treatment trees also decreased their πtlp by osmotic adjustment, and the values were lower than the minimum values of their Ψmid. In addition, the treatment trees maintained gs and Amax especially in the morning, though at midday, values decreased to half those of the control trees. Decreasing leaf water potential by osmotic adjustment to maintain gs and Amax under soil drying in treatment trees was considered to represent anisohydric behavior. These results suggest that D. aromatica may have high leaf adaptability to drought by regulating leaf water consumption and maintaining turgor pressure to improve its leaf water relations. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Lichen Persistence and Recovery in Response to Varied Volcanic Disturbances

NASA Astrophysics Data System (ADS)

Nelson, P.; Wheeler, T. B.

2015-12-01

Volcanic eruptions produce many ecological disturbances that structure vegetation. While lichens are sensitive to disturbances, little is known about their responses to volcanic disturbances, except for colonization of lava. We examined lichen community responses through time to different disturbances produced by the May 1, 2008 eruption of Volcan Chaiten in south-central Chile. Pre-eruption vegetation near the volcano was old-growth Valdivian temperate rainforest dominated by closed-canopy Nothofagus sp... In 2012, we installed thirteen 1-acre plots across volcanic disturbance zones on which a time-constrained search was done for all macrolichen species, each of which was assigned an approximate log10 categorical abundance. We also installed a 0.2 m2 quadrat on two representative trees per plot for repeat photography of lichen cover. We remeasured at least one plot per disturbance zone in 2014 and re-photographed tree quadrats in 2013 and 2014. We then analyzed species composition and abundance differences among disturbance zones. In 2012, the blast (pyroclastic density flow), scorch (standing scorched forest at the edge of the blast) and deep tephra (>10 cm) zones had the lowest lichen species richness (5-13 species), followed by reference (unimpacted) and shallow (<10 cm) tephra (17-20 species). Gravel rain (preexisting rock ejected by eruption initiation), gravel rain + pumice and flooded forests (fluvially reworked volcanic material entrained by heavy rains) were species-rich (25-42 species). In 2014, the blast and deep tephra had regained 2-3 times the number of lichen species since 2012 while the light tephra and reference were essentially unchanged. Gravel rain, gravel rain + pumice and flooded forest plots all had about the same number of species in 2014 as 2012. Lichen colonization and growth in tree quadrats varied widely, from very little colonization in the blast to prolific colonization in the gravel rain + pumice zone. Lichen's varied responses to different volcanic disturbances were attributable to varying degrees of mortality and subsequent availability of substrate, quantity of light and removal of competitors. While sensitive to disturbance, lichens are apparently resilient to and can quickly recolonize after a variety of large, violent volcanic disturbances.

A statistical rain attenuation prediction model with application to the advanced communication technology satellite project. 3: A stochastic rain fade control algorithm for satellite link power via non linear Markow filtering theory

NASA Technical Reports Server (NTRS)

Manning, Robert M.

1991-01-01

The dynamic and composite nature of propagation impairments that are incurred on Earth-space communications links at frequencies in and above 30/20 GHz Ka band, i.e., rain attenuation, cloud and/or clear air scintillation, etc., combined with the need to counter such degradations after the small link margins have been exceeded, necessitate the use of dynamic statistical identification and prediction processing of the fading signal in order to optimally estimate and predict the levels of each of the deleterious attenuation components. Such requirements are being met in NASA's Advanced Communications Technology Satellite (ACTS) Project by the implementation of optimal processing schemes derived through the use of the Rain Attenuation Prediction Model and nonlinear Markov filtering theory.

Impact of logging on aboveground biomass stocks in lowland rain forest, Papua New Guinea.

PubMed

Bryan, Jane; Shearman, Phil; Ash, Julian; Kirkpatrick, J B

2010-12-01

Greenhouse-gas emissions resulting from logging are poorly quantified across the tropics. There is a need for robust measurement of rain forest biomass and the impacts of logging from which carbon losses can be reliably estimated at regional and global scales. We used a modified Bitterlich plotless technique to measure aboveground live biomass at six unlogged and six logged rain forest areas (coupes) across two approximately 3000-ha regions at the Makapa concession in lowland Papua New Guinea. "Reduced-impact logging" is practiced at Makapa. We found the mean unlogged aboveground biomass in the two regions to be 192.96 +/- 4.44 Mg/ha and 252.92 +/- 7.00 Mg/ha (mean +/- SE), which was reduced by logging to 146.92 +/- 4.58 Mg/ha and 158.84 +/- 4.16, respectively. Killed biomass was not a fixed proportion, but varied with unlogged biomass, with 24% killed in the lower-biomass region, and 37% in the higher-biomass region. Across the two regions logging resulted in a mean aboveground carbon loss of 35 +/- 2.8 Mg/ha. The plotless technique proved efficient at estimating mean aboveground biomass and logging damage. We conclude that substantial bias is likely to occur within biomass estimates derived from single unreplicated plots.

A butterfly photographed in the La Selva region of the Costa Rican rain forest as part of NASA's AirSAR 2004 Mesoamerica campaign

NASA Image and Video Library

2004-03-04

A butterfly photographed in the La Selva region of the Costa Rican rain forest as part of NASA's AirSAR 2004 Mesoamerica campaign. AirSAR 2004 Mesoamerica is a three-week expedition by an international team of scientists that will use an all-weather imaging tool, called the Airborne Synthetic Aperture Radar (AirSAR) which is located onboard NASA's DC-8 airborne laboratory. Scientists from many parts of the world including NASA's Jet Propulsion Laboratory are combining ground research done in several areas in Central America with NASA's AirSAR technology to improve and expand on the quality of research they are able to do. NASA's AIRSAR technolgy provides two essential elements to the ground-based scientists. First, it tests and provides accurate measurements of the forest structure. Secondly, AirSAR can study a larger area of the forest versus the smaller area that can be tested and plotted by the ground scientists. It also provides a unique one-of-a-kind system of measurement that obtains important information for the scientists, such as where forests are located and what exactly is in them.

A lizard photographed in the La Selva region of the Costa Rican rain forest as part of NASA's AirSAR 2004 Mesoamerica campaign

NASA Image and Video Library

2004-03-04

A lizard photographed in the La Selva region of the Costa Rican rain forest as part of NASA's AirSAR 2004 Mesoamerica campaign. AirSAR 2004 Mesoamerica is a three-week expedition by an international team of scientists that will use an all-weather imaging tool, called the Airborne Synthetic Aperture Radar (AirSAR) which is located onboard NASA's DC-8 airborne laboratory. Scientists from many parts of the world including NASA's Jet Propulsion Laboratory are combining ground research done in several areas in Central America with NASA's AirSAR technology to improve and expand on the quality of research they are able to do. NASA's AIRSAR technolgy provides two essential elements to the ground-based scientists. First, it tests and provides accurate measurements of the forest structure. Secondly, AirSAR can study a larger area of the forest versus the smaller area that can be tested and plotted by the ground scientists. It also provides a unique one-of-a-kind system of measurement that obtains important information for the scientists, such as where forests are located and what exactly is in them.

A plant photographed in the La Selva region of the Costa Rican rain forest as part of NASA's AirSAR 2004 Mesoamerica campaign

NASA Image and Video Library

2004-03-04

A plant photographed in the La Selva region of the Costa Rican rain forest as part of NASA's AirSAR 2004 Mesoamerica campaign. AirSAR 2004 Mesoamerica is a three-week expedition by an international team of scientists that will use an all-weather imaging tool, called the Airborne Synthetic Aperture Radar (AirSAR) which is located onboard NASA's DC-8 airborne laboratory. Scientists from many parts of the world including NASA's Jet Propulsion Laboratory are combining ground research done in several areas in Central America with NASA's AirSAR technology to improve and expand on the quality of research they are able to do. NASA's AIRSAR technolgy provides two essential elements to the ground-based scientists. First, it tests and provides accurate measurements of the forest structure. Secondly, AirSAR can study a larger area of the forest versus the smaller area that can be tested and plotted by the ground scientists. It also provides a unique one-of-a-kind system of measurement that obtains important information for the scientists, such as where forests are located and what exactly is in them.

A tree trunk structure photographed in the La Selva region of the Costa Rican rain forest as part of NASA's AirSAR 2004 Mesoamerica campaign

NASA Image and Video Library

2004-03-04

A tree trunk structure photographed in the La Selva region of the Costa Rican rain forest as part of NASA's AirSAR 2004 Mesoamerica campaign. AirSAR 2004 Mesoamerica is a three-week expedition by an international team of scientists that will use an all-weather imaging tool, called the Airborne Synthetic Aperture Radar (AirSAR) which is located onboard NASA's DC-8 airborne laboratory. Scientists from many parts of the world including NASA's Jet Propulsion Laboratory are combining ground research done in several areas in Central America with NASA's AirSAR technology to improve and expand on the quality of research they are able to do. NASA's AIRSAR technolgy provides two essential elements to the ground-based scientists. First, it tests and provides accurate measurements of the forest structure. Secondly, AirSAR can study a larger area of the forest versus the smaller area that can be tested and plotted by the ground scientists. It also provides a unique one-of-a-kind system of measurement that obtains important information for the scientists, such as where forests are located and what exactly is in them.

A unique tree trunk photographed in La Selva region of the Costa Rican rain forest as part of NASA's AirSAR 2004 Mesoamerica campaign

NASA Image and Video Library

2004-03-04

A unique tree trunk photographed in La Selva region of the Costa Rican rain forest as part of NASA's AirSAR 2004 Mesoamerica campaign. AirSAR 2004 Mesoamerica is a three-week expedition by an international team of scientists that will use an all-weather imaging tool, called the Airborne Synthetic Aperture Radar (AirSAR) which is located onboard NASA's DC-8 airborne laboratory. Scientists from many parts of the world including NASA's Jet Propulsion Laboratory are combining ground research done in several areas in Central America with NASA's AirSAR technology to improve and expand on the quality of research they are able to do. NASA's AIRSAR technolgy provides two essential elements to the ground-based scientists. First, it tests and provides accurate measurements of the forest structure. Secondly, AirSAR can study a larger area of the forest versus the smaller area that can be tested and plotted by the ground scientists. It also provides a unique one-of-a-kind system of measurement that obtains important information for the scientists, such as where forests are located and what exactly is in them.

A tree frog photographed in the La Selva region of the Costa Rican rain forest as part of NASA's AirSAR 2004 Mesoamerica campaign

NASA Image and Video Library

2004-03-04

A tree frog photographed in the La Selva region of the Costa Rican rain forest as part of NASA's AirSAR 2004 Mesoamerica campaign. AirSAR 2004 Mesoamerica is a three-week expedition by an international team of scientists that will use an all-weather imaging tool, called the Airborne Synthetic Aperture Radar (AirSAR) which is located onboard NASA's DC-8 airborne laboratory. Scientists from many parts of the world including NASA's Jet Propulsion Laboratory are combining ground research done in several areas in Central America with NASA's AirSAR technology to improve and expand on the quality of research they are able to do. NASA's AIRSAR technolgy provides two essential elements to the ground-based scientists. First, it tests and provides accurate measurements of the forest structure. Secondly, AirSAR can study a larger area of the forest versus the smaller area that can be tested and plotted by the ground scientists. It also provides a unique one-of-a-kind system of measurement that obtains important information for the scientists, such as where forests are located and what exactly is in them.

This photograph shows a stream in the La Selva region of the Costa Rican rain forest, taken during NASA's AirSAR 2004 Mesoamerica campaign

NASA Image and Video Library

2004-03-04

This photograph shows a stream in the La Selva region of the Costa Rican rain forest, taken during NASA's AirSAR 2004 Mesoamerica campaign. AirSAR 2004 Mesoamerica is a three-week expedition by an international team of scientists that will use an all-weather imaging tool, called the Airborne Synthetic Aperture Radar (AirSAR) which is located onboard NASA's DC-8 airborne laboratory. Scientists from many parts of the world including NASA's Jet Propulsion Laboratory are combining ground research done in several areas in Central America with NASA's AirSAR technology to improve and expand on the quality of research they are able to do. NASA's AIRSAR technolgy provides two essential elements to the ground-based scientists. First, it tests and provides accurate measurements of the forest structure. Secondly, AirSAR can study a larger area of the forest versus the smaller area that can be tested and plotted by the ground scientists. It also provides a unique one-of-a-kind system of measurement that obtains important information for the scientists, such as where forests are located and what exactly is in them.

Modelling rainfall interception by a lowland tropical rain forest in northeastern Puerto Rico

Treesearch

J. Schellekensa; F.N. Scatenab; L.A. Bruijnzeela; A.J. \\t Wickela

1999-01-01

Recent surveys of tropical forest water use suggest that rainfall interception by the canopy is largest in wet maritime locations. To investigate the underlying processes at one such location—the Luquillo Experimental Forest in eastern Puerto Rico—66 days of detailed throughfall and above-canopy climatic data were collected in 1996 and analysed using the Rutter and...

Sensitivity of snow process simulations to precipitation-phase transition method in forested and open areas

NASA Astrophysics Data System (ADS)

Lundberg, A.; Gustafsson, D.

2009-04-01

Modeling of forest snow processes is complicated and especially problematic seems to be the separation of precipitation phase in climates where a large part of the precipitation falls at temperatures near zero degrees Celsius. When the precipitation is classified as snow, the tree crowns can carry an order of magnitude more canopy storage as compared to when the precipitation is classified as rain, and snow in the trees also alters the albedo of the forest while rain does not. Many different schemes for the precipitation phase separation are used by various snow models. Some models use just one air temperature threshold (TR/S) below which all precipitation is assumed to be snow and above which all precipitation is classified as rain. A more common approach for forest snow models is to use two temperature thresholds. The snow fraction (SF) is then set to one below the snow threshold (TS) and to zero above the rain threshold (TR) and SF is assumed to decrease linearly between these two thresholds. Also more sophisticated schemes exist, but three seems to be a lack of agreement on how the precipitation phase separations should be performed. The aim with this study is to use a hydrological model including canopy snow processes to illustrate the sensitivity for different formulations of the precipitation phase separation on a) the simulated maximum snow pack storage b) the interception evaporation loss and c) snow melt runoff. In other words, to investigate of the choice of precipitation phase separation has an impact on the simulated wintertime water balance. Simulations are made for sites in different climates and for both open fields and forest sites in different regions of Sweden from north to south. In general, precipitation phase separation methods that classified snowfall at higher temperatures resulted in a larger proportion of the precipitation lost by interception evaporation as a result of the increased interception capacity. However, the maximum snow accumulation was also increased in some cases due to the overall increased snowfall, depending on canopy density and precipitation and temperature regimes. Results show that the choice of precipitation phase separation method can have an significant impact on the simulated wintertime water balance, especially in forested regions.

Soil emissions of nitric oxide in a seasonally dry tropical forest of Mexico

NASA Technical Reports Server (NTRS)

Davidson, Eric A.; Vitousek, Peter M.; Riley, Ralph; Matson, Pamela A.; Garcia-Mendez, Georgina; Maass, J. M.

1991-01-01

Soil emissions of NO were measured at the Chamela Biological Station, Mexico, using soil covers and a field apparatus of NO detection based on CrO3 conversion of NO to NO2 and detection of NO2 by chemiluminescence with Luminol. Mean NO fluxes from forest soils ranged from 0.14 to 0.52 ng NO-N/sq cm/hr during the dry season and from 0.73 to 1.27 ng NO-N/sq cm/hr during the wet season. A fertilized floodplain pasture exhibited higher fluxes, but an unfertilized upland pasture, which represents the fastest growing land use in the region, had flux rates similar to the forest sites. Wetting experiments at the end of the dry season caused large pulses of NO flux, equaling 10 percent to 20 percent of the estimated annual NO emissions of 0.5-1.0 kg N/ha from the forest sites. Absence of a forest canopy during the dry season and the first wet season rain probably results in substantial NO(x) export from the forest system that may be important to regional atmospheric chemical processes. Wetting experiments during the wet season and a natural rain event had little or no stimulatory effect on NO flux rates.

Random Forest Application for NEXRAD Radar Data Quality Control

NASA Astrophysics Data System (ADS)

Keem, M.; Seo, B. C.; Krajewski, W. F.

2017-12-01

Identification and elimination of non-meteorological radar echoes (e.g., returns from ground, wind turbines, and biological targets) are the basic data quality control steps before radar data use in quantitative applications (e.g., precipitation estimation). Although WSR-88Ds' recent upgrade to dual-polarization has enhanced this quality control and echo classification, there are still challenges to detect some non-meteorological echoes that show precipitation-like characteristics (e.g., wind turbine or anomalous propagation clutter embedded in rain). With this in mind, a new quality control method using Random Forest is proposed in this study. This classification algorithm is known to produce reliable results with less uncertainty. The method introduces randomness into sampling and feature selections and integrates consequent multiple decision trees. The multidimensional structure of the trees can characterize the statistical interactions of involved multiple features in complex situations. The authors explore the performance of Random Forest method for NEXRAD radar data quality control. Training datasets are selected using several clear cases of precipitation and non-precipitation (but with some non-meteorological echoes). The model is structured using available candidate features (from the NEXRAD data) such as horizontal reflectivity, differential reflectivity, differential phase shift, copolar correlation coefficient, and their horizontal textures (e.g., local standard deviation). The influence of each feature on classification results are quantified by variable importance measures that are automatically estimated by the Random Forest algorithm. Therefore, the number and types of features in the final forest can be examined based on the classification accuracy. The authors demonstrate the capability of the proposed approach using several cases ranging from distinct to complex rain/no-rain events and compare the performance with the existing algorithms (e.g., MRMS). They also discuss operational feasibility based on the observed strength and weakness of the method.

Natural or anthropogenic? On the origin of atmospheric sulfate deposition in the Andes of southeastern Ecuador

NASA Astrophysics Data System (ADS)

Makowski Giannoni, S.; Rollenbeck, R.; Trachte, K.; Bendix, J.

2014-10-01

Atmospheric sulfur deposition above certain limits can represent a threat to tropical forests, causing nutrient imbalances and mobilizing toxic elements that impact biodiversity and forest productivity. Atmospheric sources of sulfur deposited by precipitation have been roughly identified in only a few lowland tropical forests. Even scarcer are studies of this type in tropical mountain forests, many of them mega-diversity hotspots and especially vulnerable to acidic deposition. In these places, the topographic complexity and related streamflow conditions affect the origin, type, and intensity of deposition. Furthermore, in regions with a variety of natural and anthropogenic sulfur sources, like active volcanoes and biomass burning, no source emission data has been used for determining the contribution of each source to the deposition. The main goal of the current study is to evaluate sulfate (SO4- deposition by rain and occult precipitation at two topographic locations in a tropical mountain forest of southern Ecuador, and to trace back the deposition to possible emission sources applying back-trajectory modeling. To link upwind natural (volcanic) and anthropogenic (urban/industrial and biomass-burning) sulfur emissions and observed sulfate deposition, we employed state-of-the-art inventory and satellite data, including volcanic passive degassing as well. We conclude that biomass-burning sources generally dominate sulfate deposition at the evaluated sites. Minor sulfate transport occurs during the shifting of the predominant winds to the north and west. Occult precipitation sulfate deposition and likely rain sulfate deposition are mainly linked to biomass-burning emissions from the Amazon lowlands. Volcanic and anthropogenic emissions from the north and west contribute to occult precipitation sulfate deposition at the mountain crest Cerro del Consuelo meteorological station and to rain-deposited sulfate at the upriver mountain pass El Tiro meteorological station.

Natural or anthropogenic? On the origin of atmospheric sulfate deposition in the Andes of southeastern Ecuador

NASA Astrophysics Data System (ADS)

Makowski Giannoni, S.; Rollenbeck, R.; Trachte, K.; Bendix, J.

2014-05-01

Atmospheric sulfur deposition above certain limits can represent a threat to tropical forests, causing nutrient imbalances and mobilizing toxic elements that impact biodiversity and forest productivity. Atmospheric sources of sulfur deposited by precipitation have being roughly identified in only a few lowland tropical forests. Even scarcer are these type of studies in tropical mountain forests, many of them megadiversity hotspots and especially vulnerable to acidic deposition. Here, the topographic complexity and related streamflow condition the origin, type, and intensity of deposition. Furthermore, in regions with a variety of natural and anthropogenic sulfur sources, like active volcanoes and biomass-burning, no source-emission data has been used for determining the contribution of each of them to the deposition. The main goal of the current study is to evaluate sulfate (SO4-) deposition by rain and occult precipitation at two topographic locations in a tropical mountain forest of southern Ecuador, and to trace back the deposition to possible emission sources applying back trajectory modeling. To link upwind natural (volcanic) and anthropogenic (urban/industrial and biomass-burning) sulfur emissions and observed sulfate deposition, we employed state of the art inventory and satellite data, including volcanic passive degassing as well. We conclude that biomass-burning sources generally dominate sulfate deposition at the evaluated sites. Minor sulfate transport occurs during the shifting of the predominant winds to the north and west. Occult precipitation sulfate deposition and likely rain sulfate deposition are mainly linked to biomass-burning emissions from the Amazon lowlands. Volcanic and anthropogenic emissions from the north and west contribute to occult precipitation sulfate deposition at the mountain crest Cerro del Consuelo meteorological station and to rain-deposited sulfate at the upriver mountain-pass El Tiro meteorological station.

Tree Circumference Dynamics in Four Forests Characterized Using Automated Dendrometer Bands

PubMed Central

McMahon, Sean M.; Detto, Matteo; Lutz, James A.; Davies, Stuart J.; Chang-Yang, Chia-Hao; Anderson-Teixeira, Kristina J.

2016-01-01

Stem diameter is one of the most commonly measured attributes of trees, forming the foundation of forest censuses and monitoring. Changes in tree stem circumference include both irreversible woody stem growth and reversible circumference changes related to water status, yet these fine-scale dynamics are rarely leveraged to understand forest ecophysiology and typically ignored in plot- or stand-scale estimates of tree growth and forest productivity. Here, we deployed automated dendrometer bands on 12–40 trees at four different forested sites—two temperate broadleaf deciduous, one temperate conifer, and one tropical broadleaf semi-deciduous—to understand how tree circumference varies on time scales of hours to months, how these dynamics relate to environmental conditions, and whether the structure of these variations might introduce substantive error into estimates of woody growth. Diurnal stem circumference dynamics measured over the bark commonly—but not consistently—exhibited daytime shrinkage attributable to transpiration-driven changes in stem water storage. The amplitude of this shrinkage was significantly correlated with climatic variables (daily temperature range, vapor pressure deficit, and radiation), sap flow and evapotranspiration. Diurnal variations were typically <0.5 mm circumference in amplitude and unlikely to be of concern to most studies of tree growth. Over time scales of multiple days, the bands captured circumference increases in response to rain events, likely driven by combinations of increased stem water storage and bark hydration. Particularly at the tropical site, these rain responses could be quite substantial, ranging up to 1.5 mm circumference expansion within 48 hours following a rain event. We conclude that over-bark measurements of stem circumference change sometimes correlate with but have limited potential for directly estimating daily transpiration, but that they can be valuable on time scales of days to weeks for characterizing changes in stem growth and hydration. PMID:28030646

The intensity of segregation of the OH-Isoprene reaction -measurements above the amazon rain forest-

NASA Astrophysics Data System (ADS)

Sörgel, Matthias; Berger, Martina; Dlugi, Ralph; Harder, Hartwig; Kesselmeier, Jürgen; Mallik, Chinmay; Marno, Daniel; Tsokankunku, Anywhere; Wolff, Stefan; Yanez-Serrano, Ana-Maria; Zelger, Michael

2017-04-01

Incomplete mixing (segregation) causes reduced reaction rates compared to laboratory values derived for well mixed conditions. The dominant contribution to atmospheric chemistry is given by the most important oxidizing agent, the OH-radical, which is regarded as the detergent of the atmosphere as it reacts with the majority of atmospheric pollutants and therefore accelerates their removal from the atmosphere. Hence, to understand atmospheric self-cleansing, we need to quantify and understand the budgets (sources and sinks) of OH. Budgets are generally derived by measuring mixing ratios of known source molecules (either primary or recycling) and the total sink for OH of which isoprene is an important part in the pristine rain forest. The production and loss terms are calculated by using the measured mixing ratios and the laboratory derived kinetic values. If reactants are not well mixed their actual reaction rates are lower in the atmosphere than in the laboratory. Therefore, segregation might play a substantial role in quantifying and understanding the derived budgets. We measured OH-radicals, isoprene and other species (O3, NOx, HO2, H2O) with high time resolution (1-10 Hz) shortly above a rain forest canopy (41 m above ground level) at the ATTO (Amazon Tall Tower Observatory) site (02°08'38.8''S, 58°59'59.5''W). The site is characterized by high isoprene (up to 20 ppb) and low NO (50 ppt - 500 ppt). Simultaneous measurements of OH and isoprene with high time resolution (necessary to directly calculate the intensity of segregation) are sparse. To our knowledge this is now the third dataset for OH-isoprene segregation but the first from a tropical rain forest. The results will be compared to modeling results from different environments and the effect of trace gas exchange driven by coherent structures on the intensity of segregation will be evaluated as well.

A statistical rain attenuation prediction model with application to the advanced communication technology satellite project. Part 2: Theoretical development of a dynamic model and application to rain fade durations and tolerable control delays for fade countermeasures

NASA Technical Reports Server (NTRS)

Manning, Robert M.

1987-01-01

A dynamic rain attenuation prediction model is developed for use in obtaining the temporal characteristics, on time scales of minutes or hours, of satellite communication link availability. Analagous to the associated static rain attenuation model, which yields yearly attenuation predictions, this dynamic model is applicable at any location in the world that is characterized by the static rain attenuation statistics peculiar to the geometry of the satellite link and the rain statistics of the location. Such statistics are calculated by employing the formalism of Part I of this report. In fact, the dynamic model presented here is an extension of the static model and reduces to the static model in the appropriate limit. By assuming that rain attenuation is dynamically described by a first-order stochastic differential equation in time and that this random attenuation process is a Markov process, an expression for the associated transition probability is obtained by solving the related forward Kolmogorov equation. This transition probability is then used to obtain such temporal rain attenuation statistics as attenuation durations and allowable attenuation margins versus control system delay.

The emergence of modern type rain forests and mangroves and their traces in the palaeobotanical record during the Late Cretaceous and early Tertiary

NASA Astrophysics Data System (ADS)

Mohr, Barbara; Coiffard, Clément

2014-05-01

The origin of modern rain forests is still very poorly known. This ecosystem could have potentially fully evolved only after the development of relatively high numbers of flowering plant families adapted to rain forest conditions. During the early phase of angiosperm evolution in the early Cretaceous the palaeo-equatorial region was located in a seasonally dry climatic belt, so that during this phase, flowering plants often show adaptations to drought, rather than to continuously wet climate conditions. Therefore it is not surprising that except for the Nymphaeales, the most basal members of extant angiosperm families have members that do not necessarily occur in the continuously wet tropics today. However, during the late Early Cretaceous several clades emerged that later would give rise to families that are typically found today mostly in (shady) moist places in warmer regions. This is especially seen among the monocotyledons, a group of the mesangiosperms, that developed in many cases large leaves often with very specific venation patterns that make these leaves very unique and well recognizable. Especially members of three groups are here of interest: the arum family (Araceae), the palms (Arecaceae) and the Ginger and allies (Zingiberales). The earliest fossil of Araceae are restricted to low latitudes during the lower Cretaceous. Arecaceae and Zingiberales do not appear in the fossil record before the early late Cretaceous and occur at mid latitudes. During the Late Cretaceous, Araceae are represented at mid latitudes by non-tropical early diverging members and at low latitudes by derived rainforest members. Palms became widespread during the Late Cretataceous and also Nypa, a typical element of tropical to subtropical mangrove environments evolved during this time period. During the Paleocene Arecaceae appear to be restricted to lower latitudes as well as Zingiberales. All three groups are again widespread during the Eocene, reaching higher latitudes and probably diversifying at mid latitudes. Later on, they slowly became restricted to lower latitudes as seen today. This fluctuation appears to be linked to climate change and are still reflected by the regional diversity of these groups, which reflect rather well rain forest evolution. When tracing the fossil record of rain forest plants we clearly see a pattern that suggests the onset of this type of environment during the late Late Cretaceous and spread during the early Tertiary with phases of retreat during the Oligocene and from the mid-Miocene onwards.

Chemical properties of forest soils

Treesearch

Charles H. Perry; Michael C. Amacher

2007-01-01

Why Is Soil Chemistry Important? The soil quality indicator was initially developed as a tool for assessing the current status of forest soil resources and predicting potential changes in soil properties. Soil chemistry data can be used to diagnose tree vigor and document the deposition of atmospheric pollutants (e.g., acid rain). This chapter focuses on two chemical...

Flood disturbance in a forested mountain landscape: interactions of land use and floods.

Treesearch

F.J. Swanson; S.L. Johnson; S.V. Gregory; S.A. Acker

1998-01-01

Recent flooding in the Pacific Northwest vividly illustrates the complexity of watershed and ecosystem responses to floods, especially in steep forest landscapes. Flooding involves a sequence of interactions that begins with climatic drivers. These drivers, generally rain and snowmelt, interact with landscape conditions, such as vegetation pattern and topography, to...

Evaluation of soil quality in areas of cocoa cabruca, forest and multicropping in southern Bahia, Brazil

USDA-ARS?s Scientific Manuscript database

The Atlantic Rain Forest is one of the most complex natural environments of the earth and, linked with this ecosystem, the cacao-cabruca system is agroforestry cultivation with an arrangement including a range of environmental, social and economical benefits and can protect many features of the biod...

Trees of Life: Saving Tropical Forests and Their Biological Wealth.

ERIC Educational Resources Information Center

Miller, Kenton; Tangley, Laura

Staggering statistics and dramatic headlines about the destruction of rain forests, the world's richest ecosystems, are only a small part of the devastating story of global deforestation. This volume provides comprehensive coverage of this complex scientific and political catastrophe-in-the-making and examines the costs and the consequences, in…

Tropical rain forest tree growth and atmospheric carbon dynamics linked to interannual temperature variation during 1984–2000

PubMed Central

Clark, D. A.; Piper, S. C.; Keeling, C. D.; Clark, D. B.

2003-01-01

During 1984–2000, canopy tree growth in old-growth tropical rain forest at La Selva, Costa Rica, varied >2-fold among years. The trees' annual diameter increments in this 16-yr period were negatively correlated with annual means of daily minimum temperatures. The tree growth variations also negatively covaried with the net carbon exchange of the terrestrial tropics as a whole, as inferred from nearly pole-to-pole measurements of atmospheric carbon dioxide (CO2) interpreted by an inverse tracer–transport model. Strong reductions in tree growth and large inferred tropical releases of CO2 to the atmosphere occurred during the record-hot 1997–1998 El Niño. These and other recent findings are consistent with decreased net primary production in tropical forests in the warmer years of the last two decades. As has been projected by recent process model studies, such a sensitivity of tropical forest productivity to on-going climate change would accelerate the rate of atmospheric CO2 accumulation. PMID:12719545

An evaluation of nitrogen and phosphorus responses to rain events in a forested watershed

NASA Astrophysics Data System (ADS)

Steadman, C.; Argerich, A.; Bladon, K. D.; Johnson, S. L.

2017-12-01

Nitrogen (N) and phosphorus (P) exhibit differential responses to storm events which reflect complex, hydrologically-driven biogeochemical activity in a watershed. However, the magnitude of the responses change throughout the year indicating that they may be strongly influenced by antecedent precipitation conditions. To evaluate N and P responses to storms, we collected storm samples from four subwatersheds in a small forested watershed over a 12-month period as well as climate and hydrologic data. We quantified dissolved nitrate (NO3-), ammonium (NH4+), total dissolved nitrogen (TDN), soluble reactive phosphorus (SRP), and total dissolved phosphorus (TDP) concentrations and exports in 300 samples and examined responses across subwatersheds and storms. To assess the influence of potential drivers, we generated a series of models with discharge, instantaneous rain, and cumulative rain as explanatory variables for analyte concentrations. We also constructed models with cumulative rain as the explanatory variable for analyte exports. There was strong evidence (p < .05) that cumulative rain or the cumulative rain-subwatershed interaction were important for all analyte exports and concentrations. In contrast, evidence was weak for the significance of instantaneous rain for any analyte concentrations while discharge or the discharge-subwatershed interaction was significant for NO3- and NH4+, respectively. Of all factors, cumulative rain was the most relevant to explain analyte concentrations (i.e., showed the highest pseudo-R2), except for NH4+, for which discharge was more relevant. There was significant spatial and temporal variability for all analyte concentrations with the exception of NH4+, which showed little variability storm-to-storm. Maximum NO3- concentration occurred at the onset of the wet season while SRP had the lowest concentration during the same time period. Differential responses of analytes evidence distinct influences of hydrologically-driven biogeochemical activity on individual analytes. However, strong correlations with cumulative rain suggest that insight may be gained through consideration of coarser factors such as antecedent precipitation conditions which may serve to integrate complexities of the hillslope, improving understanding of N and P variability.

Paying for Forest Ecosystem Services: Voluntary Versus Mandatory Payments.

PubMed

Roesch-McNally, Gabrielle E; Rabotyagov, Sergey S

2016-03-01

The emergence of new markets for forest ecosystem services can be a compelling opportunity for market diversification for private forest landowners, while increasing the provision of public goods from private lands. However, there is limited information available on the willingness-to-pay (WTP) for specific forest ecosystem services, particularly across different ecosystem market mechanisms. We utilize survey data from Oregon and Washington households to compare marginal WTP for forest ecosystem services and the total WTP for cost-effective bundles of forest ecosystem services obtained from a typical Pacific Northwest forest across two value elicitation formats representing two different ecosystem market mechanisms: an incentive-compatible choice experiment involving mandatory tax payments and a hypothetical private provision scenario modeled as eliciting contributions to the preferred forest management alternative via a provision point mechanism with a refund. A representative household's total WTP for the average forest management program was estimated at $217.59 per household/year under a mandatory tax mechanism and $160.44 per household/per year under a voluntary, crowdfunding-style, contribution mechanism; however, these estimates are not statistically different. Marginal WTP estimates were assessed for particular forest ecosystem service attributes including water quality, carbon storage, mature forest habitat, and public recreational access. This study finds that survey respondents place significant economic value on forest ecosystem services in both elicitation formats and that the distributions of the marginal WTP are not statistically significantly different.

Paying for Forest Ecosystem Services: Voluntary Versus Mandatory Payments

NASA Astrophysics Data System (ADS)

Roesch-McNally, Gabrielle E.; Rabotyagov, Sergey S.

2016-03-01

The emergence of new markets for forest ecosystem services can be a compelling opportunity for market diversification for private forest landowners, while increasing the provision of public goods from private lands. However, there is limited information available on the willingness-to-pay (WTP) for specific forest ecosystem services, particularly across different ecosystem market mechanisms. We utilize survey data from Oregon and Washington households to compare marginal WTP for forest ecosystem services and the total WTP for cost-effective bundles of forest ecosystem services obtained from a typical Pacific Northwest forest across two value elicitation formats representing two different ecosystem market mechanisms: an incentive-compatible choice experiment involving mandatory tax payments and a hypothetical private provision scenario modeled as eliciting contributions to the preferred forest management alternative via a provision point mechanism with a refund. A representative household's total WTP for the average forest management program was estimated at 217.59 per household/year under a mandatory tax mechanism and 160.44 per household/per year under a voluntary, crowdfunding-style, contribution mechanism; however, these estimates are not statistically different. Marginal WTP estimates were assessed for particular forest ecosystem service attributes including water quality, carbon storage, mature forest habitat, and public recreational access. This study finds that survey respondents place significant economic value on forest ecosystem services in both elicitation formats and that the distributions of the marginal WTP are not statistically significantly different.

Removal rates of native and exotic dung by dung beetles (Scarabaeidae: Scarabaeinae) in a fragmented tropical rain forest.

PubMed

Amézquita, Sandra; Favila, Mario E

2010-04-01

Many studies have evaluated the effect of forest fragmentation on dung beetle assemblage structure. However, few have analyzed how forest fragmentation affects the processes carried out by these insects in tropical forests where their food sources consist mainly of dung produced by native herbivore mammals. With the conversion of forests to pastures, cattle dung has become an exotic alternative and abundant food for dung beetles. This study compares dung removal rates of native (monkey) and exotic (cow) dung in different-sized fragments of tropical rain forests, during the dry and rainy seasons at the Los Tuxtlas Biosphere Reserve. Dung removal rates were affected by season, dung type, and the interaction between resource type and season. During the dry season, the removal rates of monkey dung were somewhat similar than during the rainy season, whereas the removal rates of cow dung were much higher during the rainy season. Dung beetle biomass and species richness were almost three times greater in monkey dung than in cow dung. Monkey dung attracted species belonging to the dweller, roller, and tunneler guilds; cow dung attracted mostly tunnelers. Therefore, the use of exotic dung may result in a biased misconception of the rates of dung removal in tropical forest and an underestimation of dung beetle diversity. This study highlights the importance of working with natural tropical forest resources when attempting to identify realistic tendencies concerning processes in natural habitats and those modified by fragmentation and by other human activities.

Retrieval of Vertical LAI Profiles Over Tropical Rain Forests using Waveform Lidar at La Selva, Costa Rica

NASA Technical Reports Server (NTRS)

Tang, Hao; Dubayah, Ralph; Swatantra, Anu; Hofton, Michelle; Sheldon, Sage; Clark, David B.; Blair, Bryan

2012-01-01

This study explores the potential of waveform lidar in mapping the vertical and spatial distributions of leaf area index (LAI) over the tropical rain forest of La Selva Biological Station in Costa Rica. Vertical profiles of LAI were derived at 0.3 m height intervals from the Laser Vegetation Imaging Sensor (LVIS) data using the Geometric Optical and Radiative Transfer (GORT) model. Cumulative LAI profiles obtained from LVIS were validated with data from 55 ground to canopy vertical transects using a modular field tower to destructively sample all vegetation. Our results showed moderate agreement between lidar and field derived LAI (r2=0.42, RMSE=1.91, bias=-0.32), which further improved when differences between lidar and tower footprint scales (r2=0.50, RMSE=1.79, bias=0.27) and distance of field tower from lidar footprint center (r2=0.63, RMSE=1.36, bias=0.0) were accounted for. Next, we mapped the spatial distribution of total LAI across the landscape and analyzed LAI variations over different land cover types. Mean values of total LAI were 1.74, 5.20, 5.41 and 5.62 over open pasture, secondary forests, regeneration forests after selective-logging and old-growth forests respectively. Lastly, we evaluated the sensitivities of our LAI retrieval model to variations in canopy/ground reflectance ratio and to waveform noise such as induced by topographic slopes. We found for both, that the effects were not significant for moderate LAI values (about 4). However model derivations of LAI might be inaccurate in areas of high-slope and high LAI (about 8) if ground return energies are low. This research suggests that large footprint waveform lidar can provide accurate vertical LAI profile estimates that do not saturate even at the high LAI levels in tropical rain forests and may be a useful tool for understanding the light transmittance within these canopies.

Short-term effects of a simulated acid rain upon the growth and nutrient relations of Pinus strobus, L.

Treesearch

Tim Wood; F. H. Bormann

1976-01-01

Acidified precipitation may affect the productivity of forests by altering the availability of plant nutrients of by affecting the ability of trees to absorb and assimilate those nutrients. In this study, the short-term effects of simulated acid rain (pH range 5.6 - 2.3) upon the growth and nutrient relations of Eastern White Pine seedlings (Pinus strobus...

Interception of rainfall in a young loblolly pine plantation

Treesearch

Marvin D. Hoover

1953-01-01

Those who have sought refuge during a storm have found a tree to be an effective umbrella for a light shower but leaky in a heavy rain. Even so, it is usually possible to stay slightly more dry under forest canopy than in the open. That is because a portion of the rain is stored on leaves and branches and eventually evaporated back to the air. The term interception is...

Gap formation and carbon cycling in the Brazilian Amazon: measurement using high-resolution optical remote sensing and studies in large forest plots

Treesearch

F. D. B. Espirito-Santo; M. M. Keller; E. Linder; R. C. Oliveira Junior; C. Pereira; C. G. Oliveira

2013-01-01

Background: The dynamics of gaps plays a role in the regimes of tree mortality, production of coarse woody debris (CWD) and the variability of light in the forest understory. Aims: To quantify the area affected by, and the carbon fluxes associated with, natural gap-phase disturbances in a tropical lowland evergreen rain forest by use of ground measurements and high-...

Evolution in African tropical trees displaying ploidy-habitat association: The genus Afzelia (Leguminosae).

PubMed

Donkpegan, Armel S L; Doucet, Jean-Louis; Migliore, Jérémy; Duminil, Jérôme; Dainou, Kasso; Piñeiro, Rosalía; Wieringa, Jan J; Champluvier, Dominique; Hardy, Olivier J

2017-02-01

Polyploidy has rarely been documented in rain forest trees but it has recently been found in African species of the genus Afzelia (Leguminosae), which is composed of four tetraploid rain forest species and two diploid dry forest species. The genus Afzelia thus provides an opportunity to examine how and when polyploidy and habitat shift occurred in Africa, and whether they are associated. In this study, we combined three plastid markers (psbA, trnL, ndhF), two nuclear markers (ribosomal ITS and the single-copy PEPC E7 gene), plastomes (obtained by High Throughput Sequencing) and morphological traits, with an extensive taxonomic and geographic sampling to explore the evolutionary history of Afzelia. Both nuclear DNA and morphological vegetative characters separated diploid from tetraploid lineages. Although the two African diploid species were well differentiated genetically and morphologically, the relationships among the tetraploid species were not resolved. In contrast to the nuclear markers, plastid markers revealed that one of the diploid species forms a well-supported clade with the tetraploids, suggesting historical hybridisation, possibly in relation with genome duplication (polyploidization) and habitat shift from dry to rain forests. Molecular dating based on fossil-anchored gene phylogenies indicates that extant Afzelia started diverging c. 14.5 or 20Ma while extant tetraploid species started diverging c. 7.0 or 9.4Ma according to plastid and nuclear DNA, respectively. Additional studies of tropical polyploid plants are needed to assess whether the ploidy-habitat association observed in African Afzelia would reflect a role of polyploidization in niche divergence in the tropics. Copyright © 2016 Elsevier Inc. All rights reserved.

Fallout Radioactivity and Epiphytes.

Treesearch

H. T. Odum; George Ann Briscoe; C. B. Briscoe

1970-01-01

After relatively high levels of fallout retention were dicovered in the epiphytic mossy forest of the Luquillo Mountains durin 1962, a survey of the distribution of radioactivity in the rain forest system was made with beta counting of 1500 samples supplemented with gamma spectra. High levels, up to 4138 counts per minute per gram, were found mainly in or on green...

Effects of dispersal, shrubs, and density-dependent morality on seed and seedling distributions in temperate forests

Treesearch

Janneke Hille Ris Lambers; James S. Clark

2003-01-01

Processes limiting recruitment of trees may have large impacts on forest dynamics. In this paper, we determined the effects of dispersal, shrubs (Rhododendron maximum), and density-dependent mortality on seed and seedling distributions of Southern Appalachian trees. We quantified the spatial distribution of seed rain, seed bank densities, first-year...

Species-specific Seedling Responses to Hurricane Disturbance in a Puerto Rican Rain Forest.

Treesearch

Lawrence R. Walker; D. Jean Lodge; Sandra M. Guzman-Grajales; Ned \\t Fetcher

2003-01-01

Seedling dynamics were followed in a Puerto Rican forest for 20 months following a severe hurricane to study the interactive effects of hurricane debris, nutrients, and light on seedling diversity, density, growth, and mortality. Three treatments (debris removal, an unaltered control with hurricane debris, and chemical fertilization added to hurricane debris) altered...

The Effect of Response Time on Conjoint Analysis Estimates of Rainforest Protection Values

Treesearch

Thomas Holmes; Keith Alger; Christian Zinkhan; D. Evan Mercer

1998-01-01

This paper reports the first estimutes of willingness to pay (WTP) for rain forest protection in the threatened Atlantic Coastal Forest ecosystem in northeastern Brazil. Conjoint analysis data were collected from Brazilian tourists for recreational bundles with complex prices. An ordered probit model with time-varying parameters and heteroskedastic errors was...

Climate variability, snow, and physiographic controls on storm hydro graphs in small forested basins, western Cascades, Oregon

Treesearch

Reed M. Perkins; Julia A. Jones

2008-01-01

Large floods are often attributed to the melting of snow during a rain event. This study tested how climate variability, snowpack presence, and basin physiography were related to storm hydrograph shape in three small (2) basins with old-growth forest in western Oregon. Relationships between hydrograph characteristics and precipitation...

Breeding for disease resistance in Hevea spp. - status, potential threats, and possible strategies.

Treesearch

Chaendaekattu Narayanan; Kavitha K. Mydin

2012-01-01

Hevea brasiliensis (Willd. ex A. Juss.) Müll. Arg., a forest tree native to the tropical rain forests of Central and South America, has only been recently domesticated outside its natural range of distribution. Almost all of the commercially cultivated clones of H. brasiliensis represent a very narrow genetic base...

Mass and nutrient dynamics of decaying litter from Passiflora mollissima and selected native species in a Hawaiian montane rain forest

Treesearch

Paul G. Scowcroft

1997-01-01

The structure and functioning of Acacia koa-Metrosideros polymorpha forests between 1200 and 1800 m elevation on the island of Hawaii are being threatened by Passiflora mollissima, an aggressive introduced liana from South America. This study was done to evaluate the short-term decomposition dynamics of...

Wood CO2 efflux in a primary tropical rain forest

Treesearch

Molly A. Cavaleri; Steven F. Oberbauer; Michael G. Ryan

2006-01-01

The balance between photosynthesis and plant respiration in tropical forests may substantially affect the global carbon cycle. Woody tissue CO2 efflux is a major component of total plant respiration, but estimates of ecosystem-scale rates are uncertain because of poor sampling in the upper canopy and across landscapes. To overcome these problems, we used a portable...

Estimation of Throughfall and Stemflow Bacterial Flux in a Subtropical Oak-Cedar Forest

NASA Astrophysics Data System (ADS)

Bittar, Thais B.; Pound, Preston; Whitetree, Ansley; Moore, L. Dean; Van Stan, John T.

2018-02-01

Transport pathways of microbes between ecosystem spheres (atmosphere, phyllosphere, and pedosphere) represent major fluxes in nutrient cycles and have the potential to affect microbially mediated biogeochemical processes. Novel data on bacterial fluxes from the phyllosphere to the pedosphere during rainfall via throughfall (rain dripping from/through the canopy) and stemflow (rain funneled down tree stems) are reported. Bacterial concentrations were quantified using flow cytometry and validated with quantitative polymerase chain reaction assays in rainfall samples from an oak-cedar forest in coastal Georgia (southeastern U.S.). Bacteria concentrations (cells mL-1) and storm-normalized fluxes (cells m-2 h-1, cells m-2 mm-1) were greater for cedar versus oak. Total bacterial flux was 1.5 × 1016 cells ha-1 yr-1. These previously unexamined bacterial fluxes are interpreted in the context of major elemental pools and fluxes in forests and could represent inoculum-level sources of bacteria (if alive), and organic matter and inorganic solute inputs (if lysed) to soils.

Brazil-USA Collaborative Research: Modifications by Anthropogenic Pollution of the Natural Atmospheric Chemistry and Particle Microphysics of the Tropical Rain Forest During the GoAmazon Intensive Operating Periods (IOPs)

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

Kim, Saewung

Manaus, a city of nearly two million people, represents an isolated urban area having a distinct urban pollution plume within the otherwise pristine Amazon Basin. The plume has high concentrations of oxides of nitrogen and sulfur, carbon monoxide, particle concentrations, and soot, among other pollutants. Critically, the distinct plume in the setting of the surrounding tropical rain forest serves as a natural laboratory to allow direct comparisons between periods of pollution influence to those of pristine conditions. The funded activity of this report is related to the Brazil-USA collaborative project during the two Intensive Operating Periods (wet season, 1 Febmore » - 31 Mar 2014; dry season, 15 Aug - 15 Oct 2014) of GoAmazon2014/5. The project addresses key science questions regarding the modification of the natural atmospheric chemistry and particle microphysics of the forest by present and future anthropogenic pollution.« less

The effect of water on the ground nesting habits of the giant tropical ant, Paraponera clavata.

PubMed

Elahi, Robin

2005-11-18

The large predatory ant, Paraponera clavata, exerts measurable top-down effects in wet and moist Neotropical forests, and therefore its distribution has potential ecological implications. To determine how water affects the presence of this important predator, the ground nesting ecology of P. clavata was examined with respect to various habitat characteristics. Four hectares of disturbed Costa Rican lowland rain forest were surveyed for ant colonies to determine nest distribution patterns in wet and dry habitat; significantly more colonies were found in dry habitat. Seventeen of 19 nests built on slopes of > 5 degrees inclination were positioned on the downward side of the tree, possibly using the trunk as a shield against runoff during rain showers. Moisture and pH inside nests were significantly different from adjacent soil. These results suggest that water influences the ground nesting habits of P. clavata, thus ecological differences between comparatively wet and dry portions of tropical forests may arise from the relative abundance of this ant species.

Erosion on very stony forest soil during phenomenal rain in Webster County, West Virginia

Treesearch

J. H. Patric; W. E., Jr. Kidd

1982-01-01

On July 15 and 16, 1979, at least 6 inches of rain fell in central West Virginia during 3 hours, a storm of return period longer than 1,000 years. More than 6 miles of logging roads were examined for evidences of soil erosion and sediment delivery to streams. Erosion was negligible on very stony soils where (a) logging roads were litter covered, (b) road grades were...

Assessing the controls of the snow energy balance and water available for runoff in a rain-an-snow environment

Treesearch

Adam B. Mazurkiewicz; David G. Callery; Jeffrey J. McDonnell

2008-01-01

Rain-on-snow (ROS) melt production and its contribution to water available for runoff is poorly understood. In the Pacific Northwest (PNW) of the USA, ROS drives many runoff events with turbulent energy exchanges dominating the snow energy balance (EB). While previous experimental work in the PNW (most notably the H.J. Andrews Experimental Forest (HJA» has quantified...

Isolation, diversity, and antimicrobial activity of rare actinobacteria from medicinal plants of tropical rain forests in Xishuangbanna, China.

PubMed

Qin, Sheng; Li, Jie; Chen, Hua-Hong; Zhao, Guo-Zhen; Zhu, Wen-Yong; Jiang, Cheng-Lin; Xu, Li-Hua; Li, Wen-Jun

2009-10-01

Endophytic actinobacteria are relatively unexplored as potential sources of novel species and novel natural products for medical and commercial exploitation. Xishuangbanna is recognized throughout the world for its diverse flora, especially the rain forest plants, many of which have indigenous pharmaceutical histories. However, little is known about the endophytic actinobacteria of this tropical area. In this work, we studied the diversity of actinobacteria isolated from medicinal plants collected from tropical rain forests in Xishuangbanna. By the use of different selective isolation media and methods, a total of 2,174 actinobacteria were isolated. Forty-six isolates were selected on the basis of their morphologies on different media and were further characterized by 16S rRNA gene sequencing. The results showed an unexpected level of diversity, with 32 different genera. To our knowledge, this is the first report describing the isolation of Saccharopolyspora, Dietzia, Blastococcus, Dactylosporangium, Promicromonospora, Oerskovia, Actinocorallia, and Jiangella species from endophytic environments. At least 19 isolates are considered novel taxa by our current research. In addition, all 46 isolates were tested for antimicrobial activity and were screened for the presence of genes encoding polyketide synthetases and nonribosomal peptide synthetases. The results confirm that the medicinal plants of Xishuangbanna represent an extremely rich reservoir for the isolation of a significant diversity of actinobacteria, including novel species, that are potential sources for the discovery of biologically active compounds.

[Specific features of nesting bird populations in forest-meadow-field landscapes of Meshchovsk Opolye reflect the diversity of their biotope connections].

PubMed

Kut'in, S D; Konstantinov, V M

2008-01-01

Studies on specific features of nesting bird populations in patchy landscapes were performed in Meshchovsk Opolye, Kaluga Region, from 1981 to 1990. Indices of similarity between the avifaunas of agricultural fields, lowland bogs, and small-leaved forests markedly differed from parameters of their population density in rank and value. In the series of biotopes differing in the relative amount of woodland, from central areas of small-leaved forests to forest margins and then to forest islands gradually decreasing in size, the birds segregated into two distinct groups, one characteristic of forest margins and large forest islands and the other characteristic of small and very small forest islands. Specific features of bird density distribution in forest-meadow-field landscapes of Meshchovsk Opolye reflected heterogeneity of their populations manifested in diverse connections with nesting biotopes.

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

Not Available

The environmental and economic impact of acid rain is documented for the eastern United States (New York, Wisconsin) and Canada and Scandinavia. Damage to lakes and other water resources, fisheries, forests and agriculture is emphasized.

Taxonomic and functional composition of arthropod assemblages across contrasting Amazonian forests.

PubMed

Lamarre, Greg P A; Hérault, Bruno; Fine, Paul V A; Vedel, Vincent; Lupoli, Roland; Mesones, Italo; Baraloto, Christopher

2016-01-01

Arthropods represent most of global biodiversity, with the highest diversity found in tropical rain forests. Nevertheless, we have a very incomplete understanding of how tropical arthropod communities are assembled. We conducted a comprehensive mass sampling of arthropod communities within three major habitat types of lowland Amazonian rain forest, including terra firme clay, white-sand and seasonally flooded forests in Peru and French Guiana. We examined how taxonomic and functional composition (at the family level) differed across these habitat types in the two regions. The overall arthropod community composition exhibited strong turnover among habitats and between regions. In particular, seasonally flooded forest habitats of both regions comprised unique assemblages. Overall, 17·7% (26 of 147) of arthropod families showed significant preferences for a particular habitat type. We present a first reproducible arthropod functional classification among the 147 taxa based on similarity among 21 functional traits describing feeding source, major mouthparts and microhabitats inhabited by each taxon. We identified seven distinct functional groups whose relative abundance contrasted strongly across the three habitats, with sap and leaf feeders showing higher abundances in terra firme clay forest. Our novel arthropod functional classification provides an important complement to link these contrasting patterns of composition to differences in forest functioning across geographical and environmental gradients. This study underlines that both environment and biogeographical processes are responsible for driving arthropod taxonomic composition while environmental filtering is the main driver of the variance in functional composition. © 2015 The Authors. Journal of Animal Ecology © 2015 British Ecological Society.

Researching the Rain Forest.

ERIC Educational Resources Information Center

Chazdon, Robin L.

1995-01-01

An autobiography of a female ecologist working in the Costa Rican rainforest is provided as an inspiration for girls. The scientist briefly tells her life story and describes her research activities. (LZ)

Acid rain mitigation experiment shifts a forested watershed from a net sink to a net source of nitrogen

PubMed Central

Rosi-Marshall, Emma J.; Bernhardt, Emily S.; Buso, Donald C.; Driscoll, Charles T.; Likens, Gene E.

2016-01-01

Decades of acid rain have acidified forest soils and freshwaters throughout montane forests of the northeastern United States; the resulting loss of soil base cations is hypothesized to be responsible for limiting rates of forest growth throughout the region. In 1999, an experiment was conducted that reversed the long-term trend of soil base cation depletion and tested the hypothesis that calcium limits forest growth in acidified soils. Researchers added 1,189 kg Ca2+ ha−1 as the pelletized mineral wollastonite (CaSiO3) to a 12-ha forested watershed within the Hubbard Brook Experimental Forest in the White Mountains of New Hampshire. Significant increases in the pH and acid-neutralizing capacity of soils and streamwater resulted, and the predicted increase in forest growth occurred. An unanticipated consequence of this acidification mitigation experiment began to emerge a decade later, with marked increases in dissolved inorganic nitrogen (DIN) exports in streamwater from the treated watershed. By 2013, 30-times greater DIN was exported from this base-treated watershed than from adjacent reference watersheds, and DIN exports resulting from this experiment match or exceed earlier reports of inorganic N losses after severe ice-storm damage within the study watershed. The discovery that CaSiO3 enrichment can convert a watershed from a sink to a source of N suggests that numerous potential mechanisms drive watershed N dynamics and provides new insights into the influence of acid deposition mitigation strategies for both carbon cycling and watershed N export. PMID:27335456

Acid rain mitigation experiment shifts a forested watershed from a net sink to a net source of nitrogen.

PubMed

Rosi-Marshall, Emma J; Bernhardt, Emily S; Buso, Donald C; Driscoll, Charles T; Likens, Gene E

2016-07-05

Decades of acid rain have acidified forest soils and freshwaters throughout montane forests of the northeastern United States; the resulting loss of soil base cations is hypothesized to be responsible for limiting rates of forest growth throughout the region. In 1999, an experiment was conducted that reversed the long-term trend of soil base cation depletion and tested the hypothesis that calcium limits forest growth in acidified soils. Researchers added 1,189 kg Ca(2+) ha(-1) as the pelletized mineral wollastonite (CaSiO3) to a 12-ha forested watershed within the Hubbard Brook Experimental Forest in the White Mountains of New Hampshire. Significant increases in the pH and acid-neutralizing capacity of soils and streamwater resulted, and the predicted increase in forest growth occurred. An unanticipated consequence of this acidification mitigation experiment began to emerge a decade later, with marked increases in dissolved inorganic nitrogen (DIN) exports in streamwater from the treated watershed. By 2013, 30-times greater DIN was exported from this base-treated watershed than from adjacent reference watersheds, and DIN exports resulting from this experiment match or exceed earlier reports of inorganic N losses after severe ice-storm damage within the study watershed. The discovery that CaSiO3 enrichment can convert a watershed from a sink to a source of N suggests that numerous potential mechanisms drive watershed N dynamics and provides new insights into the influence of acid deposition mitigation strategies for both carbon cycling and watershed N export.

Use of an Upland Pine Forest by the Star-Nosed Mole, Condylura Cristata

Treesearch

Timothy S. McCay; Mark J. Komoraoski; William M. Ford

1999-01-01

The star-nosed mole (Condylura cristata) is a semi-aquatic insectivore, commonly found near marshy areas and streams. We report two captures of star-nosed moles from a xeric, upland pine forest more than 500 m from the nearest persistent source of water. Both captures occurred during rainy nights, suggesting that star-nosed moles use rain events as...

The effects of wind disturbance on temperate rain forest structure and dynamics of southeast Alaska.

Treesearch

Gregory J. Nowacki; Marc G. Kramer

1998-01-01

Wind disturbance plays a fundamental role in shaping forest dynamics in southeast Alaska. Recent studies have increased our appreciation for the effects of wind at both large and small scales. Current thinking is that wind disturbance characteristics change over a continuum dependent on landscape features (e.g., exposure, landscape position, topography). Data modeling...

Relative effects of human and feral hog disturbance on a wet forest in Hawaii

Treesearch

C. John Ralph; Bruce D. Maxwell

1984-01-01

The effects of 20 months of intensive disturbance by humans, as well as the presence of feral hogs Sus scrofa, was measured on vegetation. Both forms of disturbance have been thought severely to affect Hawaiian rain forests by reduction of plant cover and allowing the proliferation of exotic plants. Despite much human use throughout the stud), area,...

Can we manage tropical landscapes? – an answer from the Caribbean perspective.

Treesearch

Ariel E. Lugo

2002-01-01

Humans have used Caribbean island landscapes for millennia. The conversion of wild lands to built-up lands or to agricultural lands in these tropical countries follows predictable patterns. Conversion of moist forest life zones and fertile flatlands is faster than conversion of wet and rain forest life zones and low fertility steep lands. In Puerto Rico, these trends...

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

Mohnen, V.A.; Aneja, V.; Bailey, B.

The report summarizes the results of the four year field measurement and data analysis program of MCCP. The MCCP is sponsored by the U.S. Environmental Protection Agency as part of the joint U.S. Forest Service-EPA Spruce-Fir Research Cooperative. The objectives of the project have been met and the result is an assessment of principal atmospheric constituents as they impact the high elevation forests of the Eastern U.S. Deposition of SO4(-2), NO3(-), H(+), and NH(4+) in cloud water represents a significant input to forest canopies with elevations greater than 1000m. Cloud water deposition can exceed wet (rain) deposition and may bemore » the dominant process for input of sulfate and nitrate compounds during the growing season in high elevation forests frequently exposed to clouds. Cloud water pH concentrations may be as much as 0.6pH units lower than pH in rain. SO(4+) and NO3(-) concentrations are also higher in cloud water than in precipitation. Ozone data reveals that significant differences exist between ozone concentrations at high elevation and low elevation sites. The primary effect of the difference is to produce higher mean ozone concentrations and longer episodes at the higher elevation sites.« less

Acid rain and its ecological consequences.

PubMed

Singh, Anita; Agrawal, Madhoolika

2008-01-01

Acidification of rain-water is identified as one of the most serious environmental problems of transboundary nature. Acid rain is mainly a mixture of sulphuric and nitric acids depending upon the relative quantities of oxides of sulphur and nitrogen emissions. Due to the interaction of these acids with other constituents of the atmosphere, protons are released causing increase in the soil acidity Lowering of soil pH mobilizes and leaches away nutrient cations and increases availability of toxic heavy metals. Such changes in the soil chemical characteristics reduce the soil fertility which ultimately causes the negative impact on growth and productivity of forest trees and crop plants. Acidification of water bodies causes large scale negative impact on aquatic organisms including fishes. Acidification has some indirect effects on human health also. Acid rain affects each and every components of ecosystem. Acid rain also damages man-made materials and structures. By reducing the emission of the precursors of acid rain and to some extent by liming, the problem of acidification of terrestrial and aquatic ecosystem has been reduced during last two decades.

Stable isotopes in nitrous oxide emitted from tropical rain forest soils and agricultural fields: Implications for the global atmospheric nitrous oxide budget

NASA Astrophysics Data System (ADS)

Perez, Tibisay Josefina

Nitrous oxide (N2O) is an important greenhouse gas and is the primary source of NOx in the stratosphere. Large uncertainties exist in the global N2O budget, mainly due to the high uncertainty associated with source estimates. Recently, stable isotopes of 15N and 18O have been proposed as a tool to better constrain the N2O global budget. This thesis develops analytical methods for constraining and measuring stable isotopes in N2O emitted from soils and reports initial investigations of N2O isotopes from the largest sources in the global N2O budget: tropical rain forest soils and agricultural fields. We found significant differences in the isotopic composition of N 2O emitted from tropical rain forest soils and fertilized agricultural fields. Differences were largest for 15N. Emission-weighted δ 15N-N2O were -26 +/- 2.5‰ s.d., n = 3 (Costa Rican forest), -6.6 +/- 11.3‰ s.d. n = 14 (Brazilian forest) and -36.7 +/- 9.2‰ s.d. n = 19 (Mexican agricultural field and Costa Rican Papaya plantation). We attribute the large range in δ 15N from tropical rain forests, where denitrification is the main source of N2O, to differences in the degree of N2O to N2 reduction. We attribute the very light δ15N values in fertilized agricultural fields to the enhanced nitrogen availability in the soils which facilitates higher fractionation between substrates and products. Similarly, in the Brazilian tropical forest lighter δ 15N-N2O from a local area of enhanced emission is attributed to locally more abundant N- substrate in that particular soil site. If the increase of N2O in the troposphere over the past 100 years is attributable to increased use of N fertilizer, and assuming that light δ 15N- N2O isotopic values are associated with agricultural practices, we expect the δ15N-N2O in the troposphere to have decreased since pre-industrial times. Theoretically, comparison of 15N and 18O signature of emitted N2O with precursors species (NO3 -, NH4+, H2O and O 2) should uniquely determine (a)the fraction of N2O produced by nitrification versus denitrification and (b)the fractionation of N2O reduced to N2. However, for this approach to be useful, in situ determinations of fractionation factors associated with nitrification and denitrification in soils are required.

Hydrology of flooded and wetland forests

USGS Publications Warehouse

Williams, T.M.; Krauss, Ken W.; Okruszko, T.; Amatya, D.; Williams, T.M.; Bren, L.; de Jong, C.

2016-01-01

In this chapter we will examine the hydrology of forested areas that are subject to soil saturation by rain, groundwater, or surface flooding. They include mangroves and other tidal forests, the forested portions of peatlands, and tree dominated wetlands defined by the Ramsar Convention (Mathews 1993). They also include estuarine tidal forests, palustrine forested wetlands, and the portion of palustrine scrub-shrub which are made up of immature tree species of the Cowardin et al. (1985) classification. A broad outline of ecology of all wetlands are described in Mitsch and Gosselink (2015), wetlands specifically with tidal influence are described by Tiner (2013), while descriptions of northern and southern forested wetlands can be found in Trettin et al. (1996) and Messina and Conner (1998) respectively.

Seed rain, soil seed bank, seed loss and regeneration of Castanopsis fargesii (Fagaceae) in a subtropical evergreen broad-leaved forest

USGS Publications Warehouse

Du, X.; Guo, Q.; Gao, X.; Ma, K.

2007-01-01

Understanding the seed rain and seed loss dynamics in the natural condition has important significance for revealing the natural regeneration mechanisms. We conducted a 3-year field observation on seed rain, seed loss and natural regeneration of Castanopsis fargesii Franch., a dominant tree species in evergreen broad-leaved forests in Dujiangyan, southwestern China. The results showed that: (1) there were marked differences in (mature) seed production between mast (733,700 seeds in 2001) and regular (51,200 and 195,600 seeds in 2002 and 2003, respectively) years for C. fargesii. (2) Most seeds were dispersed in leaf litter, humus and 0-2 cm depth soil in seed bank. (3) Frequency distributions of both DBH and height indicated that C. fargesii had a relatively stable population. (4) Seed rain, seed ground density, seed loss, and leaf fall were highly dynamic and certain quantity of seeds were preserved on the ground for a prolonged time due to predator satiation in both the mast and regular years so that the continuous presence of seed bank and seedling recruitments in situ became possible. Both longer time observations and manipulative experiments should be carried out to better understand the roles of seed dispersal and regeneration process in the ecosystem performance. ?? 2006 Elsevier B.V. All rights reserved.

Comparative proteomic analysis of differentially expressed proteins in β-aminobutyric acid enhanced Arabidopsis thaliana tolerance to simulated acid rain.

PubMed

Liu, Tingwu; Jiang, Xinwu; Shi, Wuliang; Chen, Juan; Pei, Zhenming; Zheng, Hailei

2011-05-01

Acid rain is a worldwide environmental issue that has seriously destroyed forest ecosystems. As a highly effective and broad-spectrum plant resistance-inducing agent, β-aminobutyric acid could elevate the tolerance of Arabidopsis when subjected to simulated acid rain. Using comparative proteomic strategies, we analyzed 203 significantly varied proteins of which 175 proteins were identified responding to β-aminobutyric acid in the absence and presence of simulated acid rain. They could be divided into ten groups according to their biological functions. Among them, the majority was cell rescue, development and defense-related proteins, followed by transcription, protein synthesis, folding, modification and destination-associated proteins. Our conclusion is β-aminobutyric acid can lead to a large-scale primary metabolism change and simultaneously activate antioxidant system and salicylic acid, jasmonic acid, abscisic acid signaling pathways. In addition, β-aminobutyric acid can reinforce physical barriers to defend simulated acid rain stress. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Characterizing the phylogenetic tree community structure of a protected tropical rain forest area in Cameroon.

PubMed

Manel, Stéphanie; Couvreur, Thomas L P; Munoz, François; Couteron, Pierre; Hardy, Olivier J; Sonké, Bonaventure

2014-01-01

Tropical rain forests, the richest terrestrial ecosystems in biodiversity on Earth are highly threatened by global changes. This paper aims to infer the mechanisms governing species tree assemblages by characterizing the phylogenetic structure of a tropical rain forest in a protected area of the Congo Basin, the Dja Faunal Reserve (Cameroon). We re-analyzed a dataset of 11538 individuals belonging to 372 taxa found along nine transects spanning five habitat types. We generated a dated phylogenetic tree including all sampled taxa to partition the phylogenetic diversity of the nine transects into alpha and beta components at the level of the transects and of the habitat types. The variation in phylogenetic composition among transects did not deviate from a random pattern at the scale of the Dja Faunal Reserve, probably due to a common history and weak environmental variation across the park. This lack of phylogenetic structure combined with an isolation-by-distance pattern of taxonomic diversity suggests that neutral dispersal limitation is a major driver of community assembly in the Dja. To assess any lack of sensitivity to the variation in habitat types, we restricted the analyses of transects to the terra firme primary forest and found results consistent with those of the whole dataset at the level of the transects. Additionally to previous analyses, we detected a weak but significant phylogenetic turnover among habitat types, suggesting that species sort in varying environments, even though it is not predominating on the overall phylogenetic structure. Finer analyses of clades indicated a signal of clustering for species from the Annonaceae family, while species from the Apocynaceae family indicated overdispersion. These results can contribute to the conservation of the park by improving our understanding of the processes dictating community assembly in these hyperdiverse but threatened regions of the world.

Use of isotopic and hydrometric monitoring methods to partition hydrologic contributions to forested wetlands in the Upper Peninsula of Michigan

NASA Astrophysics Data System (ADS)

Van Grinsven, M. J.; Pypker, T. G.; Kolka, R. K.

2012-12-01

As a result of their landscape position and physical soil properties, northern forested wetlands are capable of retaining springtime snowmelt, rain and near surface groundwater inputs into the growing season. Hydrological conditions such as source water chemistry, duration of inundation, and magnitude of water table fluctuations are affected by the relative contribution of snow, rain, and groundwater sources, and in turn these hydrological conditions strongly influence the structure and function of northern forested wetlands. Black ash (Fraxinus nigra) is a facultative wet tree species, and is known to occur in 23 U.S. states and 7 Canadian provinces in northeastern North America. Black ash trees have ecological, economic, and cultural significance, and are currently threatened by the rapid expansion of the exotic emerald ash borer (Burprestidae: Agrilus planipennis). Since its initial detection in 2002 near Detroit, MI, the emerald ash borer has killed millions of ash trees in 15 U.S. states and 2 Canadian provinces. There is very little known about black ash wetland hydrology and ecology, and as a result of the looming infestation, there is a critical need to gain a better understanding of the hydrology in undisturbed ecosystems. The main objective of this study is to partition source water contributions in black ash wetlands in the western Upper Peninsula of Michigan. We hypothesize that snowmelt and near surface groundwater supply the majority of water to these wetlands annually, and summer rain is readily removed from the system through the evapotranspiration pathway. Hydrometric monitoring methods were used in conjunction with isotopic analysis using a linear mixing model to characterize source water contributions in nine black ash wetlands. The results suggest a connection with near surface groundwater during spring and early summer, and a short residence time for rain water following summer storm events. The outcome of this research aims to inform land managers in northeastern North America about the natural hydrologic condition of black ash wetlands, and provide baseline data that underscores potential water and forest resource impacts of current and future emerald ash borer infestations.

Remote analysis of biological invasion and biogeochemical change

PubMed Central

Asner, Gregory P.; Vitousek, Peter M.

2005-01-01

We used airborne imaging spectroscopy and photon transport modeling to determine how biological invasion altered the chemistry of forest canopies across a Hawaiian montane rain forest landscape. The nitrogen-fixing tree Myrica faya doubled canopy nitrogen concentrations and water content as it replaced native forest, whereas the understory herb Hedychium gardnerianum reduced nitrogen concentrations in the forest overstory and substantially increased aboveground water content. This remote sensing approach indicates the geographic extent, intensity, and biogeochemical impacts of two distinct invaders; its wider application could enhance the role of remote sensing in ecosystem analysis and management. PMID:15761055

Revealing Forest Harvesting Effects on Large Peakflows in Rain-On-Snow Environment with a New Stochastic Framework

NASA Astrophysics Data System (ADS)

Rong, W. N.; Alila, Y.

2017-12-01

Using nine pairs of control-treatment watersheds with varying climate, physiography, and harvesting practices in the Rain-On-Snow (ROS) environment of the Pacific Northwest region, we explore the linkage between environmental control and the sensitivity of peakflow response to harvesting effects. Compared to previous paired watershed studies in ROS environment, we employed an experimental design of Frequency Pairing to isolate the effects of disturbances on systems' response. In contrary, the aspect of changing frequency distributions is not commonly invoked in previous literatures on the topic of forests and floods. Our results show how harvesting can dramatically increase the magnitude of all peakflows on record and how such effects can increase with increasing return periods, as a consequence of substantial increases to the mean and variance of the peakflow frequency distribution. Most critically, peakflows with return period larger than 10 years can increase in frequency, where the larger the peakflow event the more frequent it may become. The sensitivity of the upper tail of the frequency distribution of peakflows was found to be linked to the physiographic and climatic characteristics via a unifying synchronization / desynchronization spatial scaling mechanism that controls the generation of rain-on-snow runoff. This new physically-based stochastic hydrology understanding on the response of watersheds in ROS environments runs counter the deterministic prevailing wisdom of forest hydrology, which presumes a limited and diminishing role of forest cover as the magnitude of the peakflow event increases. By demonstrating the need for invoking the dimension of frequency in the understanding and prediction of the effects of harvesting on peakflows, findings from this study suggested that pure deterministic hypotheses and experimental designs that solely focusing on the changing magnitude of peakflows have been misguiding forest hydrology research for over a century on this topic.

Nutrient additions to a tropical rain forest drive substantial soil carbon dioxide losses to the atmosphere.

PubMed

Cleveland, Cory C; Townsend, Alan R

2006-07-05

Terrestrial biosphere-atmosphere carbon dioxide (CO(2)) exchange is dominated by tropical forests, where photosynthetic carbon (C) uptake is thought to be phosphorus (P)-limited. In P-poor tropical forests, P may also limit organic matter decomposition and soil C losses. We conducted a field-fertilization experiment to show that P fertilization stimulates soil respiration in a lowland tropical rain forest in Costa Rica. In the early wet season, when soluble organic matter inputs to soil are high, P fertilization drove large increases in soil respiration. Although the P-stimulated increase in soil respiration was largely confined to the dry-to-wet season transition, the seasonal increase was sufficient to drive an 18% annual increase in CO(2) efflux from the P-fertilized plots. Nitrogen (N) fertilization caused similar responses, and the net increases in soil respiration in response to the additions of N and P approached annual soil C fluxes in mid-latitude forests. Human activities are altering natural patterns of tropical soil N and P availability by land conversion and enhanced atmospheric deposition. Although our data suggest that the mechanisms driving the observed respiratory responses to increased N and P may be different, the large CO(2) losses stimulated by N and P fertilization suggest that knowledge of such patterns and their effects on soil CO(2) efflux is critical for understanding the role of tropical forests in a rapidly changing global C cycle.

Soil Phosphorus Fractionation during Forest Development on Landslide Scars in the Luquillo Mountains, Puerto Rico.

Treesearch

Jacqueline Frizano; Arthur H. Johnson; David R. Vann; Frederick N. Scatena

2002-01-01

Mineral soils from a chronosequence of landslide scars ranging in age from 1 to more than 55 years in a subtropical montane rain forest of eastern Puerto Rico were used to determine the rate at which labile P capital recovers during primary succession. Nine organic and inorganic soil P fractions were measured using the Hedley sequential extraction procedure. Deep soil...

Nature and extent of macropores in forest soils and their influence on subsurface water movement

Treesearch

Gerald M. Aubertin; Gerald M. Aubertin

1971-01-01

Rain, falling on a sloping forested soil, may enter the soil quickly and move considerable distances through the soil by way of macropores. A macropore is a large pore, cavity, passageway, channel, tunnel, or void in the soil, through which water usually drains by gravity. Large quantities of water can move through the soil by way of these macropores-without...

Distribution, ecology and behavior of Anochetus kempfi (Hymenoptera: Formicidae) and description of the sexual forms

Treesearch

J.A. Torres; R.R. Snelling; T.H. Jones

2000-01-01

The ponerine, Anochetus kempft Brown, is a cryptic nocturnal ant, widely distributed in Puerto Rico and the Virgin Islands. It is found in various habitats ranging from dry forest to rain forest. Males and the ergatoid queens are here described and illustrated for the first time. Mature colonies contain about 100 workers and may include several queens. We have observed...

Whole tree xylem sap flow responses to multiple environmental variables in a wet tropical forest

Treesearch

J.J. O' Brien; S.F. Oberbauer; D.B. Clark

2004-01-01

In order to quantify and characterize the variance in rain-forest tree physiology, whole tree sap flow responses to local environmental conditions were investigated in 10 species of trees with diverse traits at La Selva Biological Station, Costa Rica. A simple model was developed to predict tree sap flow responses to a synthetic environmental variable generated by a...

Lake and bulk sampling chemistry, NADP, and IMPROVE air quality data analysis on the Bridger-Teton National Forest (USFS Region 4)

Treesearch

Jill Grenon; Terry Svalberg; Ted Porwoll; Mark Story

2010-01-01

Air quality monitoring data from several programs in and around the Bridger-Teton (B-T) National Forest - National Atmospheric Deposition Program (NADP), longterm lake monitoring, long-term bulk precipitation monitoring (both snow and rain), and Interagency Monitoring of Protected Visual Environments (IMPROVE) - were analyzed in this report. Trends were analyzed using...

Carbon farming in hot, dry coastal areas: an option for climate change mitigation

NASA Astrophysics Data System (ADS)

Becker, K.; Wulfmeyer, V.; Berger, T.; Gebel, J.; Münch, W.

2013-07-01

We present a comprehensive, interdisciplinary project which demonstrates that large-scale plantations of Jatropha curcas - if established in hot, dry coastal areas around the world - could capture 17-25 t of carbon dioxide per hectare per year from the atmosphere (over a 20 yr period). Based on recent farming results it is confirmed that the Jatropha curcas plant is well adapted to harsh environments and is capable of growing alone or in combination with other tree and shrub species with minimal irrigation in hot deserts where rain occurs only sporadically. Our investigations indicate that there is sufficient unused and marginal land for the widespread cultivation of Jatropha curcas to have a significant impact on atmospheric CO2 levels at least for several decades. In a system in which desalinated seawater is used for irrigation and for delivery of mineral nutrients, the sequestration costs were estimated to range from 42-63 EUR per tonne CO2. This result makes carbon farming a technology that is competitive with carbon capture and storage (CCS). In addition, high-resolution simulations using an advanced land-surface-atmosphere model indicate that a 10 000 km2 plantation could produce a reduction in mean surface temperature and an onset or increase in rain and dew fall at a regional level. In such areas, plant growth and CO2 storage could continue until permanent woodland or forest had been established. In other areas, salinization of the soil may limit plant growth to 2-3 decades whereupon irrigation could be ceased and the captured carbon stored as woody biomass.

Hydrologic and forest management controls on DOC dynamics in the small watersheds of the H.J. Andrews Experimental Forest, OR

NASA Astrophysics Data System (ADS)

Lajtha, K.; Jones, J. A.

2016-12-01

Dissolved organic carbon (DOC) export from hillslopes to streams is an important component of the carbon cycle of a catchment and may be a critical source of energy for the aquatic food web in receiving waters. Using a long-term record of DOC and other dissolved nutrients and elements from paired watersheds from the H.J. Andrews Experimental Forest in Oregon, we explored hydrologic, climatic, and land-use controls on seasonal and inter-annual patterns of DOC flux in a seasonally dry ecosystem. Seasonal patterns of DOC flux demonstrated source limitations to DOC export, with DOC concentrations highest immediately following the first rains after a dry summer, and lowest after winter rains. In contrast, more geochemically-controlled elements showed simple dilution-concentration patterns with no seasonal hysteresis. Inter-annual patterns of DOC flux, however, did not provide evidence of source limitation, with DOC flux within a watershed tightly correlated to total discharge but not temperature. Among watersheds, forest harvest, even over 50 years ago, significantly reduced DOC flux but not fluxes of other elements including N; this response was linked to the loading of coarse woody debris to the forest floor. Chemical fingerprinting of DOC revealed that old-growth watersheds had higher fluxes of DOC characteristic of forest floor organic materials, likely delivered to streams through more surficial preferential flow pathways not subject to microbial alteration, respiration, or sorption losses. Taken together these results suggest that the biogeochemical composition of forested streams reflects both current hydrologic patterns and also processes that occurred many decades ago within the catchment.

Nutrient fluxes in litterfall of a secondary successional alluvial rain forest in Southern Brazil.

PubMed

Scheer, Maurício Bergamini; Gatti, Gustavo; Wisniewski, Celina

2011-12-01

During forest succession, litterfall nutrient fluxes increase significantly. The higher inputs of organic matter and nutrients through litterfall affects positively soil fertility and the species composition, which are essential components in forest restoration and management programs. In the present study, the input of nutrients to the forest soil via litterfall components was estimated for two sites of different development stages, in an early successional alluvial rain forest in Brazil. Litterfall returned to the soil, in kg/ha, ca. 93 N, 79 Ca, 24 K, 15 Mg, 6 P, 1.7 Mn, 0.94 Fe, 0.18 Zn, 0.09 Cu and 11.2 Al, in the site where trees were more abundant and had higher values of basal area. In the other area, where trees where less abundant and values of basal area were comparatively low, litterfall returned < 50% of those amounts to the forest soil, except for Al. The amount of Al that returned to the soil was similar in both areas due to the high contribution of Tibouchina pulchra (82% of Al returned). Comparatively, high proportion of three dominant native tree species (Myrsine coriacea, T. pulchra and Cecropia pachystachya) explained better litter nutrient use efficiency (mainly N and P) in the site with the least advanced successional stage. Although litterfall of these species show lower nutrient concentrations than the other tree species, their nutrient fluxes were high in both sites, indicating a certain independence from soil essential nutrients. Such feature of the native species is very advantageous and should be considered in forest restoration programs.

Spatial characterization of acid rain stress in Canadian Shield lakes

NASA Technical Reports Server (NTRS)

Tanis, Fred J.

1986-01-01

A major concern of the acid rain problem is the cumulative ecosystem damage to lakes and forests. The number of lakes affected in northeastern United States and on the Canadian Shield is thought to be enormous. Seasonal changes in lake transparency are examined relative to annual acidic load. The relationship between variations in lake acidification and ecophysical units is being examined. Finally, the utility of Thematic Mapper (TM) based observations is being used to measure seasonal changes in the optical transparency in acid lakes.

Epidemiology today: Mitigating threats to an ecosystem.

PubMed

Kreiger, Nancy

2016-06-27

Ecosystems comprise all the living and non-living things in a particular area (e.g., rain forest, desert), which interact and maintain equilibrium. Loss of equilibrium (e.g., clear-cutting trees in a rain forest) can mean the decline of the ecosystem, unless it is able to adapt to the new circumstances. The term "knowledge ecosystem" describes an approach to managing knowledge in a particular field; the components of this system include the people, the technological skills and resources, and information or data. Epidemiology can be thought of as a knowledge ecosystem and, like ecological systems, its existence can be threatened, from both internal and external forces that may alter its equilibrium. This paper describes some threats to the epidemiology knowledge ecosystem, how these threats came about, and what responses we can make that may serve to mitigate those threats.

Isolation, Diversity, and Antimicrobial Activity of Rare Actinobacteria from Medicinal Plants of Tropical Rain Forests in Xishuangbanna, China▿ †

PubMed Central

Qin, Sheng; Li, Jie; Chen, Hua-Hong; Zhao, Guo-Zhen; Zhu, Wen-Yong; Jiang, Cheng-Lin; Xu, Li-Hua; Li, Wen-Jun

2009-01-01

Endophytic actinobacteria are relatively unexplored as potential sources of novel species and novel natural products for medical and commercial exploitation. Xishuangbanna is recognized throughout the world for its diverse flora, especially the rain forest plants, many of which have indigenous pharmaceutical histories. However, little is known about the endophytic actinobacteria of this tropical area. In this work, we studied the diversity of actinobacteria isolated from medicinal plants collected from tropical rain forests in Xishuangbanna. By the use of different selective isolation media and methods, a total of 2,174 actinobacteria were isolated. Forty-six isolates were selected on the basis of their morphologies on different media and were further characterized by 16S rRNA gene sequencing. The results showed an unexpected level of diversity, with 32 different genera. To our knowledge, this is the first report describing the isolation of Saccharopolyspora, Dietzia, Blastococcus, Dactylosporangium, Promicromonospora, Oerskovia, Actinocorallia, and Jiangella species from endophytic environments. At least 19 isolates are considered novel taxa by our current research. In addition, all 46 isolates were tested for antimicrobial activity and were screened for the presence of genes encoding polyketide synthetases and nonribosomal peptide synthetases. The results confirm that the medicinal plants of Xishuangbanna represent an extremely rich reservoir for the isolation of a significant diversity of actinobacteria, including novel species, that are potential sources for the discovery of biologically active compounds. PMID:19648362

Economic Analysis of Planting Forests on Rice Lands in Texas: Sequestering Carbon and Avoiding Methane Production

NASA Astrophysics Data System (ADS)

Kronrad, G. D.; Huang, C.

2005-12-01

Global climate change is predicted due to increases in greenhouse gasses (i.e. CO2, CH4, CFCs, N2O, O3) in the atmosphere caused by human activities. The atmospheric concentration of methane (CH4), which absorbs and retains heat 21 times more effectively than CO2, has increased. Anaerobic bacterial activity in rice paddies constitutes one of major emission sources of CH4. The rice fields of Texas, for example, accounted for an annual CH4 emission of between 1.1 and 1.6 million tons of CO2 equivalent between 1990 and 2000. Converting marginal rice fields to forests plantations will remove CO2 from the atmosphere, sequester carbon in the forests and prevent the production of CH4. Therefore, carbon credits can be claimed for the carbon sequestered and the avoidance of CH4 production. Analyses were conducted to calculate the amount of carbon sequestered and methane avoided, and the profitability, measured in net present worth (NPW), of managing loblolly pine plantation for 1) timber production only, 2) the dual products of timber products and carbon credits in forests planted on marginal agricultural and unused pastureland and 3) the dual products of timber and carbon storage in forests planted on marginal rice lands. Calculations were performed using three discount rates, three site qualities and five prices for carbon credits. The results indicate that on average quality land, using a discount rate of 8 percent, forests planted on marginal agricultural and unused pastureland earn a NPW of 346 per acre from timber production only; a NPW of 438 per acre from timber and carbon credits (54.4 tons of carbon sequestered), assuming carbon is worth 10 per ton, during one rotation (32 years). The profitability of forest management increases due to the inclusion of carbon credits. The profitability of planting forests on marginal rice fields is even higher, earning a NPW of 566 per acre from timber and carbon credits (54.4 tons of C sequestered and 33.3 tons of C emission avoided).

Flying in the rain: hovering performance of Anna's hummingbirds under varied precipitation.

PubMed

Ortega-Jimenez, Victor Manuel; Dudley, Robert

2012-10-07

Flight in rain represents a greater challenge for smaller animals because the relative effects of water loading and drop impact are greater at reduced scales given the increased ratios of surface area to mass. Nevertheless, it is well known that small volant taxa such as hummingbirds can continue foraging even in extreme precipitation. Here, we evaluated the effect of four rain intensities (i.e. zero, light, moderate and heavy) on the hovering performance of Anna's hummingbirds (Calypte anna) under laboratory conditions. Light-to-moderate rain had only a marginal effect on flight kinematics; wingbeat frequency of individuals in moderate rain was reduced by 7 per cent relative to control conditions. By contrast, birds hovering in heavy rain adopted more horizontal body and tail positions, and also increased wingbeat frequency substantially, while reducing stroke amplitude when compared with control conditions. The ratio between peak forces produced by single drops on a wing and on a solid surface suggests that feathers can absorb associated impact forces by up to approximately 50 per cent. Remarkably, hummingbirds hovered well even under heavy precipitation (i.e. 270 mm h(-1)) with no apparent loss of control, although mechanical power output assuming perfect and zero storage of elastic energy was estimated to be about 9 and 57 per cent higher, respectively, compared with normal hovering.

Physiological characteristics of tropical rain forest tree species: a basis for the development of silvicultural technology.

PubMed

Sasaki, Satohiko

2008-01-01

The physiological characteristics of the dominant tree species in the tropical rain forest mainly belonging to dipterocarps as well as the environmental conditions especially for the light in the forest were studied to establish the silvicultural system for the forest regeneration in the tropical South Asia. The flowering patterns of the dipterocarp trees are usually irregular and unpredictable, which make difficult to collect sufficient seeds for raising the seedlings. The field survey revealed the diverged features of the so-called gregarious or simultaneous flowering of various species of this group. Appropriate conditions and methods for the storage of the seeds were established according to the detailed analyses of the morphological and physiological characteristics of the seeds such as the low temperature tolerance and the moisture contents. The intensity and spectra of the light in the forest primarily determine the growth and the morphological development of the seedlings under the canopy. Based on the measurements of the diffused light at the sites in the tropical forest in the varying sunlight, the parameters such as "the steady state of the diffuse light" and "the turning point" were defined, which were useful to evaluate the light conditions in the forest. To improve the survival of the transplanted seedlings, a planting method of "the bare-root seedlings", the seedlings easy to be handled by removal of all leaves, soil and pots, was developed. Its marked efficiency was proved with various dipterocarps and other tropical trees by the field trial in the practical scale. Tolerance of the various species to the extreme environmental conditions such as fires, acid soils and drought were examined by the experiments and the field survey, which revealed marked adaptability of Shorea roxburghii as a potential species for regeneration of the tropical forests.

Cocoa Intensification Scenarios and Their Predicted Impact on CO2 Emissions, Biodiversity Conservation, and Rural Livelihoods in the Guinea Rain Forest of West Africa

NASA Astrophysics Data System (ADS)

Gockowski, Jim; Sonwa, Denis

2011-08-01

The Guinean rain forest (GRF) of West Africa, identified over 20 years ago as a global biodiversity hotspot, had reduced to 113,000 km2 at the start of the new millennium which was 18% of its original area. The principal driver of this environmental change has been the expansion of extensive smallholder agriculture. From 1988 to 2007, the area harvested in the GRF by smallholders of cocoa, cassava, and oil palm increased by 68,000 km2. Field results suggest a high potential for significantly increasing crop yields through increased application of seed-fertilizer technologies. Analyzing land-use change scenarios, it was estimated that had intensified cocoa technology, already developed in the 1960s, been pursued in Cote d'Ivoire, Ghana, Nigeria and Cameroon that over 21,000 km2 of deforestation and forest degradation could have been avoided along with the emission of nearly 1.4 billion t of CO2. Addressing the low productivity of agriculture in the GRF should be one of the principal objectives of REDD climate mitigation programs.

Identification of stress biomarkers for drought and increased soil temperature in seedlings of European beech ( Fagus sylvatica )

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

Popović, Milica; Gregori, Marco; Vodnik, Dominik

Drought is an environmental stress that impacts plant productivity. Projections show both an increase in intense rain events and a reduction in the number of rain days, conditions that leads to increased risk of drought. Consequently, the identification of molecular biomarkers suitable for evaluating the impact of water deprivation conditions on forest plant seedlings is of significant value for monitoring purposes and forest management. In this study, we evaluated a biochemical methodology for the assessment of drought stress coupled with variable soil temperature in European beech (Fagus sylvatica L.) seedlings by analyzing a set of metabolites and enzymes involved inmore » free radical scavenging and cell wall synthesis. The results indicate that the specific activities and isoform profile of superoxide dismutases and glutathione peroxidases together with the variation of phenolic compounds enable discrimination between seedlings with different degrees of photosynthetic activity. This approach represents a promising platform for the assessment of drought stress in forest trees and could serve for enhancing selection and breeding practices, allowing for plants that are more tolerant of abiotic stress.« less

Pre-Columbian archaeological ruins are revealed through Costa Rican rain forest in this photo taken during NASA's AirSAR 2004 campaign

NASA Image and Video Library

2004-03-05

Pre-Columbian archaeological ruins are revealed through Costa Rican rain forest in this photo taken during NASA's AirSAR 2004 Mesoamerica campaign. AirSAR 2004 Mesoamerica is a three-week expedition by an international team of scientists that uses an all-weather imaging tool, called the Airborne Synthetic Aperture Radar (AirSAR) which is located onboard NASA's DC-8 airborne laboratory. The radar, developed by NASA's Jet Propulsion Laboratory, can penetrate clouds and also collect data at night. Its high-resolution sensors operate at multiple wavelengths and modes, allowing AirSAR to see beneath treetops, through thin sand, and dry snow pack. Much of the archaeological evidence needed to understand Pre-Columbian societies in Central America comes from features on the landscape. Difficult terrain and logistics have limited ground data collection. AirSAR helped to detect signs of ancient civilizations hidden beneath the forest. Its images will shed insights into the way modern humans interact with their landscape, and how ancient peoples lived and what became of their civilizations.

Seedling mortality in Hawaiian rain forest: The role of small-scale physical disturbance

USGS Publications Warehouse

Drake, D.R.; Pratt, L.W.

2001-01-01

Most montane rain forests on the island of Hawaii consist of a closed canopy formed by Cibotium spp. tree ferns beneath an open canopy of emergent Metrosideros polymorpha trees. We used artificial seedlings to assess the extent to which physical disturbance caused by the senescing fronds of tree ferns and the activities of feral pigs might limit tree regeneration. Artificial seedlings were established terrestrially (N = 300) or epiphytically (N = 300) on tree fern stems. Half of the seedlings on each substrate were in an exclosure lacking feral pigs and half were in forest with pigs present. After one year, the percentage of seedlings damaged was significantly greater among terrestrial seedlings (25.7%) than epiphytic seedlings (11.3%). Significantly more terrestrial seedlings were damaged in the presence of pigs (31.3%) than in the absence of pigs (20.0%). Senescing fronds of tree ferns were responsible for 60.3 percent of the damaged seedlings. Physical disturbance is potentially a major cause of seedling mortality and may reduce the expected half-life of a seedling cohort to less than two years.

Implications of Warm Rain in Shallow Cumulus and Congestus Clouds for Large-Scale Circulations

NASA Astrophysics Data System (ADS)

Nuijens, Louise; Emanuel, Kerry; Masunaga, Hirohiko; L'Ecuyer, Tristan

2017-11-01

Space-borne observations reveal that 20-40% of marine convective clouds below the freezing level produce rain. In this paper we speculate what the prevalence of warm rain might imply for convection and large-scale circulations over tropical oceans. We present results using a two-column radiative-convective model of hydrostatic, nonlinear flow on a non-rotating sphere, with parameterized convection and radiation, and review ongoing efforts in high-resolution modeling and observations of warm rain. The model experiments investigate the response of convection and circulation to sea surface temperature (SST) gradients between the columns and to changes in a parameter that controls the conversion of cloud condensate to rain. Convection over the cold ocean collapses to a shallow mode with tops near 850 hPa, but a congestus mode with tops near 600 hPa can develop at small SST differences when warm rain formation is more efficient. Here, interactive radiation and the response of the circulation are crucial: along with congestus a deeper moist layer develops, which leads to less low-level radiative cooling, a smaller buoyancy gradient between the columns, and therefore a weaker circulation and less subsidence over the cold ocean. The congestus mode is accompanied with more surface precipitation in the subsiding column and less surface precipitation in the deep convecting column. For the shallow mode over colder oceans, circulations also weaken with more efficient warm rain formation, but only marginally. Here, more warm rain reduces convective tops and the boundary layer depth—similar to Large-Eddy Simulation (LES) studies—which reduces the integrated buoyancy gradient. Elucidating the impact of warm rain can benefit from large-domain high-resolution simulations and observations. Parameterizations of warm rain may be constrained through collocated cloud and rain profiling from ground, and concurrent changes in convection and rain in subsiding and convecting branches of circulations may be revealed from a collocation of space-borne sensors, including the Global Precipitation Measurement (GPM) and upcoming Aeolus missions.

Rain attenuation statistics over millimeter wave bands in South Korea

NASA Astrophysics Data System (ADS)

Shrestha, Sujan; Choi, Dong-You

2017-01-01

Rain induced degradations are significant for terrestrial microwave links operating at frequencies higher than 10 GHz. Paper presents analyses done on rain attenuation and rainfall data for three years between 2013 till 2015, in 3.2 km experimental link of 38 GHz and 0.1 km link at 75 GHz. The less link distance is maintained for 75 GHz operating frequency in order to have better recording of propagation effect as such attenuation induced by rain. OTT Parsivel is used for collection of rain rate database which show rain rate of about 50 mm/h and attenuation values of 20.89 and 28.55 dB are obtained at 0.01% of the time for vertical polarization under 38 and 75 GHz respectively. Prediction models, namely, ITU-R P. 530-16, Da Silva Mello, Moupfouma, Abdulrahman, Lin and differential equation approach are analyzed. This studies help to identify most suitable rain attenuation model for higher microwave bands. While applying ITU-R P. 530-16, the relative error margin of about 3%, 38% and 42% along with 80, 70, 61% were obtained in 0.1%, 0.01% and 0.001% of the time for vertical polarization under 38 and 75 GHz respectively. Interestingly, ITU-R P. 530-16 shows relatively closer estimation to measured rain attenuation at 75 GHz with relatively less error probabilities and additionally, Abdulrahman and ITU-R P. 530-16 results in better estimation to the measured rain attenuation at 38 GHz link. The performance of prominent rain attenuation models are judged with different error matrices as recommended by ITU-R P. 311-15. Furthermore, the efficacy of frequency scaling technique of rain attenuation between links distribution are also discussed. This study shall be useful for making good considerations in rain attenuation predictions for terrestrial link operating at higher frequencies.

Discovering Diversity.

ERIC Educational Resources Information Center

Manner, Barbara M.; Hattler, Jean Anne

2000-01-01

Introduces a preservice teacher field trip to the rain forests and coastal areas. This experience develops an awareness for different cultures among preservice teachers by experiencing biological and cultural diversity in Costa Rica. Presents students' own ideas on this experience. (YDS)

Why are Wetlands Important?

EPA Pesticide Factsheets

Wetlands are among the most productive ecosystems in the world, comparable to rain forests and coral reefs. An immense variety of species of microbes, plants, insects, amphibians, reptiles, birds, fish, and mammals can be part of a wetland ecosystem.

Singapore

NASA Image and Video Library

2011-05-26

This image from NASA Terra spacecraft is of the Republic of Singapore, a city-state off the southern tip of the Malay Peninsula. An island country made up of 63 islands, the country is largely urbanized with very little rain forest left.

[Relationship between simulated acid rain stress and leaf reflectance].

PubMed

Song, Xiao-dong; Jiang, Hong; Yu, Shu-quan; Zhou, Guo-mo; Jiang, Zi-shan

2010-01-01

Acid rain is a worldwide environmental problem. Serious acid rain pollution in subtropical China has constituted a potential threat to the health of the local forest. In the present paper, the changing properties of the chlorophyll concentration and spectral reflectance at the visible wavelengths for the six subtropical broad-leaved tree species leaves under simulated acid rain (SAR) treatment with different pH levels were studied. With the increasing strength of the SAR, the chlorophyll concentrations of the experimental species under pH 2.5 and pH 4.0 treatment were higher than that under pH 5.6; the spectral reflectance at the visible wavelengths for pH 2.5 and pH 4.0 were lower than that for pH 5.6 in general; while there weren't significant differences between pH 2.5 and pH 4.0. After the treatment with different levels of SAR, the differences in spectral reflectance at the visible wavelengths mainly focused around the green peak and red edge on the reflectance curve. The subtropical broad-leaved tree species studied were relatively not sensitive to acid rain stresses; some stronger acid rain may accelerate the growth of the tree species used here to some extent.

Effects of forest practices on peak flows and consequent channel response: a state-of-science report for western Oregon and Washington.

Treesearch

Gordon E. Grant; Sarah L. Lewis; Frederick J. Swanson; John H. Cissel; Jeffrey J. McDonnell

2008-01-01

This is a state-of-the-science synthesis of the effects of forest harvest activities on peak flows and channel morphology in the Pacific Northwest, with a specific focus on western Oregon and Washington. We develop a database of relevant studies reporting peak flow data across rain-, transient-, and snow-dominated hydrologic zones, and provide a quantitative comparison...

Forests in decline: yellow-cedar research yields prototype for climate change adaptation planning

Treesearch

Marie Oliver; Paul Hennon; David D' Amore

2013-01-01

Yellow-cedar has been dying across 600 miles of North Pacific coastal rain forest—from Alaska to British Columbia—since about 1880. Thirty years ago, a small group of pathologists began investigating possible biotic causes of the decline. When no biotic cause could be found, the scope broadened into a research program that eventually encompassed the fields of ecology,...

[Seasonal variation of soil respiration and its components in tropical rain forest and rubber plantation in Xishuangbanna, Yunnan].

PubMed

Lu, Hua-Zheng; Sha, Li-Qing; Wang, Jun; Hu, Wen-Yan; Wu, Bing-Xia

2009-10-01

By using trenching method and infrared gas analyzer, this paper studied the seasonal variation of soil respiration (SR), including root respiration (RR) and heterotrophic respiration (HR), in tropical seasonal rain forest (RF) and rubber (Hevea brasiliensis) plantation (RP) in Xishuangbanna of Yunnan, China. The results showed that the SR and HR rates were significantly higher in RF than in RP (P < 0.01), while the RR rate had less difference between the two forests. Soil temperature and moisture were the key factors affecting the SR, RR and HR. The SR and HR rates in the two forests were rainy season > dry-hot season > foggy season, but the RR rate was rainy season > foggy season > dry-hot season in RF, and foggy season > rainy season > dry-hot season in RP. The contribution of RR to SR in RF (29%) was much lower than that in RP (42%, P < 0.01), while the contribution of HR to SR was 71% in RF and 58% in RP. When the soil temperature at 5 cm depth varied from 12 degrees C to 32 degrees C, the Q10 values for SR, HR, and RR rates were higher in RF than in RP. HR had the highest Q10 value, while RR had the lowest one.

Degraded tropical rain forests possess valuable carbon storage opportunities in a complex, forested landscape.

PubMed

Alamgir, Mohammed; Campbell, Mason J; Turton, Stephen M; Pert, Petina L; Edwards, Will; Laurance, William F

2016-07-20

Tropical forests are major contributors to the terrestrial global carbon pool, but this pool is being reduced via deforestation and forest degradation. Relatively few studies have assessed carbon storage in degraded tropical forests. We sampled 37,000 m(2) of intact rainforest, degraded rainforest and sclerophyll forest across the greater Wet Tropics bioregion of northeast Australia. We compared aboveground biomass and carbon storage of the three forest types, and the effects of forest structural attributes and environmental factors that influence carbon storage. Some degraded forests were found to store much less aboveground carbon than intact rainforests, whereas others sites had similar carbon storage to primary forest. Sclerophyll forests had lower carbon storage, comparable to the most heavily degraded rainforests. Our findings indicate that under certain situations, degraded forest may store as much carbon as intact rainforests. Strategic rehabilitation of degraded forests could enhance regional carbon storage and have positive benefits for tropical biodiversity.

Degraded tropical rain forests possess valuable carbon storage opportunities in a complex, forested landscape

PubMed Central

Alamgir, Mohammed; Campbell, Mason J.; Turton, Stephen M.; Pert, Petina L.; Edwards, Will; Laurance, William F.

2016-01-01

Tropical forests are major contributors to the terrestrial global carbon pool, but this pool is being reduced via deforestation and forest degradation. Relatively few studies have assessed carbon storage in degraded tropical forests. We sampled 37,000 m2 of intact rainforest, degraded rainforest and sclerophyll forest across the greater Wet Tropics bioregion of northeast Australia. We compared aboveground biomass and carbon storage of the three forest types, and the effects of forest structural attributes and environmental factors that influence carbon storage. Some degraded forests were found to store much less aboveground carbon than intact rainforests, whereas others sites had similar carbon storage to primary forest. Sclerophyll forests had lower carbon storage, comparable to the most heavily degraded rainforests. Our findings indicate that under certain situations, degraded forest may store as much carbon as intact rainforests. Strategic rehabilitation of degraded forests could enhance regional carbon storage and have positive benefits for tropical biodiversity. PMID:27435389

Degraded tropical rain forests possess valuable carbon storage opportunities in a complex, forested landscape

NASA Astrophysics Data System (ADS)

Alamgir, Mohammed; Campbell, Mason J.; Turton, Stephen M.; Pert, Petina L.; Edwards, Will; Laurance, William F.

2016-07-01

Tropical forests are major contributors to the terrestrial global carbon pool, but this pool is being reduced via deforestation and forest degradation. Relatively few studies have assessed carbon storage in degraded tropical forests. We sampled 37,000 m2 of intact rainforest, degraded rainforest and sclerophyll forest across the greater Wet Tropics bioregion of northeast Australia. We compared aboveground biomass and carbon storage of the three forest types, and the effects of forest structural attributes and environmental factors that influence carbon storage. Some degraded forests were found to store much less aboveground carbon than intact rainforests, whereas others sites had similar carbon storage to primary forest. Sclerophyll forests had lower carbon storage, comparable to the most heavily degraded rainforests. Our findings indicate that under certain situations, degraded forest may store as much carbon as intact rainforests. Strategic rehabilitation of degraded forests could enhance regional carbon storage and have positive benefits for tropical biodiversity.

Bioenergy production and forest landscape change in the southeastern United States

USGS Publications Warehouse

Costanza, Jennifer K.; Abt, Robert C.; McKerrow, Alexa; Collazo, Jaime A.

2016-01-01

Production of woody biomass for bioenergy, whether wood pellets or liquid biofuels, has the potential to cause substantial landscape change and concomitant effects on forest ecosystems, but the landscape effects of alternative production scenarios have not been fully assessed. We simulated landscape change from 2010 to 2050 under five scenarios of woody biomass production for wood pellets and liquid biofuels in North Carolina, in the southeastern United States, a region that is a substantial producer of wood biomass for bioenergy and contains high biodiversity. Modeled scenarios varied biomass feedstocks, incorporating harvest of ‘conventional’ forests, which include naturally regenerating as well as planted forests that exist on the landscape even without bioenergy production, as well as purpose-grown woody crops grown on marginal lands. Results reveal trade-offs among scenarios in terms of overall forest area and the characteristics of the remaining forest in 2050. Meeting demand for biomass from conventional forests resulted in more total forest land compared with a baseline, business-as-usual scenario. However, the remaining forest was composed of more intensively managed forest and less of the bottomland hardwood and longleaf pine habitats that support biodiversity. Converting marginal forest to purpose-grown crops reduced forest area, but the remaining forest contained more of the critical habitats for biodiversity. Conversion of marginal agricultural lands to purpose-grown crops resulted in smaller differences from the baseline scenario in terms of forest area and the characteristics of remaining forest habitats. Each scenario affected the dominant type of land-use change in some regions, especially in the coastal plain that harbors high levels of biodiversity. Our results demonstrate the complex landscape effects of alternative bioenergy scenarios, highlight that the regions most likely to be affected by bioenergy production are also critical for biodiversity, and point to the challenges associated with evaluating bioenergy sustainability.

Biomass Burning:Significant Source of Nitrate and Sulfate for the Andean Rain Forest in Ecuador

NASA Astrophysics Data System (ADS)

Fabian, P.; Rollenbeck, R.; Spichtinger, N.

2009-04-01

Forest fires are significant sources of carbon, sulfur and nitrogen compounds which, along with their photochemically generated reaction products, can be transported over very long distances, even traversing oceans. Chemical analyses of rain and fogwater samples collected on the wet eastern slopes of the Ecuadorian Andes show frequent episodes of high sulfate and nitrate concentration, from which annual deposition rates of about14 kg/ha and 7 kg/ha ,respectively, are derived. These are comparable to those observed in polluted central Europe. Regular rain and fogwater sampling along an altitude profile between 1800 and 3185 m, has been carried out since 2002.The research area located at 30 58'S ,790 5' W is dominated by trade winds from easterly directions. The samples, generally accumulated over 1-week intervals, were analysed for pH, conductivity and major ions(K+,Na+,NH4+,Ca2+,Mg 2+,SO42-,NO3-,PO43-).For all components a strong seasonal variation is observed, while the altitudinal gradient is less pronounced. About 65 % of the weekly samples were significantly loaded with cations and anions, with pH often as low 3.5 to 4.0 and conductivity up to 50 uS/cm. Back trajectories (FLEXTRA) showed that respective air masses had passed over areas of intense biomass burning, sometimes influenced by volcanoes, ocean spray, or even episodic Sahara and/or Namib desert dust interference not discussed here. Enhanced SO4 2-and NO3- were identified, by combining satellite-based fire pixels with back trajectories, as predominantly resulting from biomass burning. For most cases, by using emission inventories, anthropogenic precursor sources other than forest fires play a minor role, thus leaving biomass burning as the main source of nitrate and sulphate in rain and fogwater. Some SO4 2- , about 10 % of the total input, could be identified to originate from active volcanoes, whose plumes were sometimes encountered by the respective back trajectories. While volcanic, oceanic and desert sources are natural, large scale biomass burning is an anthropogenic source which adds about 7 kg/ha of NO3- and 14 kg/ha of SO4 2- per year to the forest which has developed on poor acidic soil conditions. Controlled fertilizing experiments within an interdisciplinary research consortium are presently carried out to investigate the impact of this disturbance on the forest ecosystem and its biodiversity.

[Response of forest bird communities to forest gap in winter in southwestern China].

PubMed

Zhao, Dong-Dong; Wu, Ying-Huan; Lu, Zhou; Jiang, Guang-Wei; Zhou, Fang

2013-06-01

Although forest gap ecology is an important field of study, research remains limited. By plot setting and point counted observation, the response of birds to forest gaps in winter as well as bird distribution patterns in forest gaps and intact canopies were studied in a north tropical monsoon forest of southwestern China from November 2011 to February 2012 in the Fangcheng Golden Camellia National Nature Reserve, Guangxi. The regression equation of bird species diversity to habitat factor was Y1=0.611+0.002 X13+0.043 X2+0.002 X5-0.003 X8+0.006 X10+0.008 X1 and the regression equation of bird species dominance index to habitat factor was Y3=0.533+0.001 X13+0.019 X2+0.002 X3-0.017 X4+0.002 X1. There were 45 bird species (2 orders and 13 families) recorded in the forest gap, accounting for 84.9% of all birds (n=45), with an average of 9.6 species (range: 2-22). Thirty-nine bird species (5 orders and 14 families) were recorded in non-gap areas, accounting for 73.6% of all birds (n=39), with an average of 5.3 species (range: 1-12). These results suggested that gap size, arbor average height (10 m from gap margin), arbor quantity (10 m from gap margin), shrub quantity (10 m from gap margin), herbal average coverage (1 m from gap margin) and bare land ratio were the key forest gap factors that influenced bird diversities. On the whole, bird diversity in the forest gap was greater than in the intact canopy. Spatial distributions in the forest gaps were also observed in the bird community. Most birds foraged in the "middle" and "canopy" layers in the vertical stratification. In addition, "nearly from" and "close from" contained more birds in relation to horizontal stratification. Feeding niche differentiation was suggested as the main reason for these distribution patterns.

Multiple antibiotic resistant Escherichia coli from a tropical rain forest stream

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

Carrasco, C.E.; Alvarez, H.J.; Ortiz, N.

1988-12-31

High densities of fecal coliforms were obtained from a pristine site and sewage contaminated site in a tropical rain forest watershed in Puerto Rico. Confirmation of fecal coliform isolates as Escherichia coli was significantly lower than for temperate waters. Antibiotic resistance and multiple antibiotic resistance were common for isolates at both sites; however, the site receiving sewage effluent had a greater proportion of multiple antibiotic resistant isolates. R. plasmids were recovered from 4 MAR isolates, 2 from each site. All recovered plasmids were approximately 1 kilobase. The recovered plasmid were also capable of transforming E. coli HB101 in vitro. Themore » high concentrations of enterobacteriaceae, small R-plasmid size, R-plasmid transformability, and long term survival of fecal origin bacteria in tropical freshwater environments give increasing importance to adequate sewage treatment, and better indicator monitoring methods for tropical areas.« less

Dispersal assembly of rain forest tree communities across the Amazon basin

PubMed Central

Lavin, Mathew; Torke, Benjamin M.; Twyford, Alex D.; Kursar, Thomas A.; Coley, Phyllis D.; Drake, Camila; Hollands, Ruth; Pennington, R. Toby

2017-01-01

We investigate patterns of historical assembly of tree communities across Amazonia using a newly developed phylogeny for the species-rich neotropical tree genus Inga. We compare our results with those for three other ecologically important, diverse, and abundant Amazonian tree lineages, Swartzia, Protieae, and Guatteria. Our analyses using phylogenetic diversity metrics demonstrate a clear lack of geographic phylogenetic structure, and show that local communities of Inga and regional communities of all four lineages are assembled by dispersal across Amazonia. The importance of dispersal in the biogeography of Inga and other tree genera in Amazonian and Guianan rain forests suggests that speciation is not driven by vicariance, and that allopatric isolation following dispersal may be involved in the speciation process. A clear implication of these results is that over evolutionary timescales, the metacommunity for any local or regional tree community in the Amazon is the entire Amazon basin. PMID:28213498

Dispersal assembly of rain forest tree communities across the Amazon basin.

PubMed

Dexter, Kyle G; Lavin, Mathew; Torke, Benjamin M; Twyford, Alex D; Kursar, Thomas A; Coley, Phyllis D; Drake, Camila; Hollands, Ruth; Pennington, R Toby

2017-03-07

We investigate patterns of historical assembly of tree communities across Amazonia using a newly developed phylogeny for the species-rich neotropical tree genus Inga We compare our results with those for three other ecologically important, diverse, and abundant Amazonian tree lineages, Swartzia , Protieae, and Guatteria Our analyses using phylogenetic diversity metrics demonstrate a clear lack of geographic phylogenetic structure, and show that local communities of Inga and regional communities of all four lineages are assembled by dispersal across Amazonia. The importance of dispersal in the biogeography of Inga and other tree genera in Amazonian and Guianan rain forests suggests that speciation is not driven by vicariance, and that allopatric isolation following dispersal may be involved in the speciation process. A clear implication of these results is that over evolutionary timescales, the metacommunity for any local or regional tree community in the Amazon is the entire Amazon basin.

Long-term treatment of onchocerciasis patients from the Liberian rain-forest with low doses of diethylcarbamazine citrate after complete nodulectomy.

PubMed

Albiez, E J

1983-12-01

60 completely nodulectomized volunteers from the Liberian rain-forest were given an initial treatment with diethylcarbamazine citrate (DEC-C) for one week with gradually increasing doses up to a total of 1.1 g per patient. A long-term treatment followed with 50 mg DEC-C per week for 12 months. Immediately after the initial treatment the mean microfilarial density decreased to 4% to 6% of the pre-treatment level. After one year the microfilarial density had again increased to 12% to 29% of the pre-treatment level. Although the intake of the weekly 50 mg DEC-C was in no case regular, the microfilarial densities could be kept at a low level throughout the trial. However, even with the combined treatment--preceding nodulectomy and long-term trial with DEC-C--it was not possible to get the patients free from microfilariae.

Wound botulism acquired in the Amazonian rain forest of Ecuador.

PubMed

Reller, Megan E; Douce, Richard W; Maslanka, Susan E; Torres, Darwin S; Manock, Stephen R; Sobel, Jeremy

2006-04-01

Wound botulism results from colonization of a contaminated wound by Clostridium botulinum and the anaerobic in situ production of a potent neurotoxin. Between 1943, when wound botulism was first recognized, and 1990, 47 laboratory-confirmed cases, mostly trauma-associated, were reported in the United States. Since 1990, wound botulism associated with injection drug use emerged as the leading cause of wound botulism in the United States; 210 of 217 cases reported to the Centers for Disease Control and Prevention between 1990 and 2002 were associated with drug injection. Despite the worldwide distribution of Clostridium botulinum spores, wound botulism has been reported only twice outside the United States, Europe, and Australia. However, wound botulism may go undiagnosed and untreated in many countries. We report two cases, both with type A toxin, from the Ecuadorian rain forest. Prompt clinical recognition, supportive care, and administration of trivalent equine botulinum antitoxin were life-saving.

Changes in forest productivity across Alaska consistent with biome shift

Treesearch

Peter S.A. Beck; Glenn P. Juday; Claire Alix; Valerie A. Barber; Stephen E. Winslow; Emily E. Sousa; Patricia Heiser; James D. Herriges; Scott J. Goetz

2011-01-01

Global vegetation models predict that boreal forests are particularly sensitive to a biome shift during the 21st century. This shift would manifest itself first at the biome's margins, with evergreen forest expanding into current tundra while being replaced by grasslands or temperate forest at the biome's southern edge. We evaluated changes in forest...

[Relative abundance, population structure, habitat preferences and activity patterns of Tapirus bairdii (Perissodactyla: Tapiridae), in Chimalapas forest, Oaxaca, Mexico].

PubMed

Lira-Torres, Iván; Briones-Salas, Miguel; Sánchez-Rojas, Gerardo

2014-12-01

Baird's tapir (Tapirus bairdii) is endangered primarily because of habitat loss and fragmentation, and overhunting throughout its distribution range. One of the priority land areas for the conservation of this species is the Northern part of its range in the Chimalapas forest, Oaxaca. The aim of this research was to determine the relative abundance, population struc- ture, habitat preferences and activity patterns of Baird's tapir (Tapirus bairdii) in the Chimalapas forest, Oaxaca, Mexico, through the non-invasive technique of camera-trap sampling. A total of five sampling sessions were undertaken among 2009-2013, and used a total of 30 camera-traps in each period. The determinant factor of the sampling design was the hunting between two study areas. A total sampling effort of 9000 trap-days allowed to estimate an index of relative abundance (IRA) of 6.77 tapir photographs/1,000 trap-days (n = 61). IRA varied significantly between sampling stations (Mann-Whitney, p < 0.01). The frequency of Baird's tapir photos was higher in the dry season in tropical rain forest without hunting (χ2, p < 0.5). In the rainy season, the tropical rain forest and secondary vegetation habitats showed higher photo frequency than expected from random (χ2, p < 0.5). Considering population structure, a 95.08% of adult animals was obtained in photographic records (n = 58). Three types of activity pattern were observed, with more nocturnal records (88.33%; Kruskal-Wallis, p < 0.05). The Chimalapas forest appears to be the second most important terrestrial priority ecoregion, just after the Mayan Forest (Campeche, Chiapas, Quintana Roo), for the conservation of tapir populations, not only for Mexico but also for Central America.

Case study: Rainfall partitioning across a natural-to-urban forest gradient during an extreme rain event

NASA Astrophysics Data System (ADS)

Akin, B. H.; Van Stan, J. T., II; Cote, J. F.; Jarvis, M. T.; Underwood, J.; Friesen, J.; Hildebrandt, A.; Maldonado, G.

2017-12-01

Trees' partitioning of rainfall is an important first process along the rainfall-to-runoff pathway that has economically significant influences on urban stormwater management. However, important knowledge gaps exist regarding (1) its role during extreme storms and (2) how this role changes as forest structure is altered by urbanization. Little research has been conducted on canopy rainfall partitioning during large, intense storms, likely because canopy water storage is rapidly overwhelmed (i.e., 1-3 mm) by short duration events exceeding, for example, 80 mm of rainfall. However, canopy structure controls more than just storage; it also affects the time for rain to drain to the surface (becoming throughfall) and the micrometeorological conditions that drive wet canopy evaporation. In fact, observations from an example extreme ( 100 mm with maximum 5-minute intensities exceeding 55 mm/h) storm across a urban-to-natural gradient in pine forests in southeast Georgia (USA), show that storm intensities were differentially dampened by 33% (tree row), 28% (forest fragment), and 17% (natural forests). In addition, maximum wet canopy evaporation rates were higher for the exposed tree row (0.18 mm/h) than for the partially-enclosed fragment canopy (0.14 mm/h) and the closed canopy natural forest site (0.11). This resulted in interception percentages decreasing from urban-to-natural stand structures (25% to 16%). A synoptic analysis of the extreme storm in this case study also shows that the mesoscale meteorological conditions that developed the heavy rainfall is expected to occur more often with projected climate changes.

Natural and anthropogenic drivers of calcium depletion in a northern forest during the last millennium.

PubMed

Leys, Bérangère A; Likens, Gene E; Johnson, Chris E; Craine, Joseph M; Lacroix, Brice; McLauchlan, Kendra K

2016-06-21

The pace and degree of nutrient limitation are among the most critical uncertainties in predicting terrestrial ecosystem responses to global change. In the northeastern United States, forest growth has recently declined along with decreased soil calcium (Ca) availability, suggesting that acid rain has depleted soil Ca to the point where it may be a limiting nutrient. However, it is unknown whether the past 60 y of changes in Ca availability are strictly anthropogenic or partly a natural consequence of long-term ecosystem development. Here, we report a high-resolution millennial-scale record of Ca and 16 other elements from the sediments of Mirror Lake, a 15-ha lake in the White Mountains of New Hampshire surrounded by northern hardwood forest. We found that sedimentary Ca concentrations had been declining steadily for 900 y before regional Euro-American settlement. This Ca decline was not a result of serial episodic disturbances but instead the gradual weathering of soils and soil Ca availability. As Ca availability was declining, nitrogen availability concurrently was increasing. These data indicate that nutrient availability on base-poor, parent materials is sensitive to acidifying processes on millennial timescales. Forest harvesting and acid rain in the postsettlement period mobilized significant amounts of Ca from watershed soils, but these effects were exacerbated by the long-term pattern. Shifting nutrient limitation can potentially occur within 10,000 y of ecosystem development, which alters our assessments of the speed and trajectory of nutrient limitation in forests, and could require reformulation of global models of forest productivity.

Natural and anthropogenic drivers of calcium depletion in a northern forest during the last millennium

PubMed Central

Leys, Bérangère A.; Likens, Gene E.; Craine, Joseph M.; Lacroix, Brice; McLauchlan, Kendra K.

2016-01-01

The pace and degree of nutrient limitation are among the most critical uncertainties in predicting terrestrial ecosystem responses to global change. In the northeastern United States, forest growth has recently declined along with decreased soil calcium (Ca) availability, suggesting that acid rain has depleted soil Ca to the point where it may be a limiting nutrient. However, it is unknown whether the past 60 y of changes in Ca availability are strictly anthropogenic or partly a natural consequence of long-term ecosystem development. Here, we report a high-resolution millennial-scale record of Ca and 16 other elements from the sediments of Mirror Lake, a 15-ha lake in the White Mountains of New Hampshire surrounded by northern hardwood forest. We found that sedimentary Ca concentrations had been declining steadily for 900 y before regional Euro-American settlement. This Ca decline was not a result of serial episodic disturbances but instead the gradual weathering of soils and soil Ca availability. As Ca availability was declining, nitrogen availability concurrently was increasing. These data indicate that nutrient availability on base-poor, parent materials is sensitive to acidifying processes on millennial timescales. Forest harvesting and acid rain in the postsettlement period mobilized significant amounts of Ca from watershed soils, but these effects were exacerbated by the long-term pattern. Shifting nutrient limitation can potentially occur within 10,000 y of ecosystem development, which alters our assessments of the speed and trajectory of nutrient limitation in forests, and could require reformulation of global models of forest productivity. PMID:27298361

Paludified forests of Komi Republic (Northeastern Europe) do not act as hotspots of the CH4 emissions

NASA Astrophysics Data System (ADS)

Schneider, Julia; Lukasheva, Maria; Gudyrev, Vasiliy; Mikhaylov, Oleg; Miglovets, Mikhail

2015-04-01

In the Komi Republic, which is situated in Northeastern Europe and is subject of Russian Federation, 306,000km2 or about 73 % of the total area are covered by forest. The predominant part of these forests lies within the boreal zone. Within the boreal forests the vegetation patterns are a result of the moisture characteristics and air temperature. Based on the moisture conditions forest communities can be grouped into wet, mesic and dry sites. In conditions of high soil moisture content forest peatlands can develop. In boreal forest landscapes it is not a rare phenomenon and can reach coverage of up to one third of the total area. In addition to the high water content of the soils forested peatlands are characterised by low soil temperatures, high organic matter accumulation and low organic matter decomposition. The thick moss-organic layer on the forest floor and waterlogged soils favours methanogenesis. Such process of accumulation of poorly decomposed organic matter mostly originating from Sphagnum which involves the formation of waterlogged conditions is defined as paludification. Highly favourable to forest paludification are sites characterised by fine-textured soils which highly hamper percolation. Paludified forests also occur at peatland margins as a result of peatland expansion. During the last years peatland margins were considered as potential biogeochemical hotspots within the peatlands and due to their high nutrient and dissolved organic matter content they may also be a major methane emitter. Paludification can also occur at forests sites after clear cutting, which is a very intensive logging type and usually leads to water table elevations. In this study measurements were conducted at peatland margins and at a clear cut site during two climatically different years. The summer of the year 2013 was considerably warmer and drier, and the summer of the year 2014 was considerably colder and wetter than the long term mean. In this study we show, that regardless of the weather conditions and the water table levels related thereto, the peatland margins did not act as strong methane emitter but are mostly sources of methane and the clear cut sites emit very small amounts of methane or are even sinks for atmospheric methane.

Ecological gradients within a Pennsylvanian mire forest

USGS Publications Warehouse

DiMichele, W.A.; Falcon-Lang, H. J.; Nelson, W.J.; Elrick, S.D.; Ames, P.R.

2007-01-01

Pennsylvanian coals represent remains of the earliest peat-forming rain forests, but there is no current consensus on forest ecology. Localized studies of fossil forests suggest intermixture of taxa (heterogeneity), while, in contrast, coal ball and palynological analyses imply the existence of pronounced ecological gradients. Here, we report the discovery of a spectacular fossil forest preserved over ???1000 ha on top of the Pennsylvanian (Desmoinesian) Herrin (No. 6) Coal of Illinois, United States. The forest was abruptly drowned when fault movement dropped a segment of coastal mire below sea level. In the largest study of its kind to date, forest composition is statistically analyzed within a well-constrained paleogeographic context. Findings resolve apparent conflicts in models of Pennsylvanian mire ecology by confirming the existence of forest heterogeneity at the local scale, while additionally demonstrating the emergence of ecological gradients at landscape scale. ?? 2007 The Geological Society of America.

Detecting tree-fall gap disturbances in tropical rain forests with airborne lidar

NASA Astrophysics Data System (ADS)

Espirito-Santo, F. D. B.; Saatchi, S.; Keller, M.

2017-12-01

Forest inventory studies in the Amazon indicate a large terrestrial carbon sink. However, field plots may fail to represent forest mortality processes at landscape-scales of tropical forests. Here we characterize the frequency distribution of tree-fall gap disturbances in natural forests of tropical forests using a novel combination of forest inventory and airborne lidar data. We quantify gap size frequency distribution along vertical and horizontal dimensions in ten Neotropical forest canopies distributed across gradients of climate and landscapes using airborne lidar measurements. We assessed all canopy openings related to each class of tree height which yields a three dimensional structure of the distribution of canopy gaps. Gap frequency distributions from lidar CHM data vary markedly with minimum gap size thresholds, but we found that natural forest disturbances (tree-fall gaps) follow a power-law distribution with narrow range of power-law exponents (-1.2 to -1.3). These power-law exponents from gap frequency distributions provide insights into how natural forest disturbances are distributed over tropical forest landscape.

Non-indigenous bamboo along headwater streams of the Luquillo Mountains, Puerto Rico: leaf fall, aquatic leaf decay and patterns of invasion

Treesearch

PAUL J. O' CONNOR; ALAN P. COVICH; F. N. SCATENA; LLOYD L. LOOPE

2000-01-01

The introduction of bamboo to montane rain forests of the Luquillo Mountains, Puerto Rico in the 1930s and 1940s has led to present-day bamboo monocultures in numerous riparian areas. When a non-native species invades a riparian ecosystem, in-stream detritivores can be affected. Bamboo dynamics expected to in¯uence stream communities in the Luquillo Experimental Forest...

An improved method of chemical analysis for low levels of nitrogen in forest streams or in rainwater.

Treesearch

Elly E. Holcombe; Duane G. Moore; Richard L. Fredriksen

1986-01-01

A modification of the macro-Kjeldahl method that provides increased sensitivity was developed for determining very low levels of nitrogen in forest streams and in rain-water. The method is suitable as a routine laboratory procedure. Analytical range of the method is 0.02 to 1.5 mg/L with high recovery and excellent precision and ac-curacy. The range can be increased to...

Flying in the rain: hovering performance of Anna's hummingbirds under varied precipitation

PubMed Central

Ortega-Jimenez, Victor Manuel; Dudley, Robert

2012-01-01

Flight in rain represents a greater challenge for smaller animals because the relative effects of water loading and drop impact are greater at reduced scales given the increased ratios of surface area to mass. Nevertheless, it is well known that small volant taxa such as hummingbirds can continue foraging even in extreme precipitation. Here, we evaluated the effect of four rain intensities (i.e. zero, light, moderate and heavy) on the hovering performance of Anna's hummingbirds (Calypte anna) under laboratory conditions. Light-to-moderate rain had only a marginal effect on flight kinematics; wingbeat frequency of individuals in moderate rain was reduced by 7 per cent relative to control conditions. By contrast, birds hovering in heavy rain adopted more horizontal body and tail positions, and also increased wingbeat frequency substantially, while reducing stroke amplitude when compared with control conditions. The ratio between peak forces produced by single drops on a wing and on a solid surface suggests that feathers can absorb associated impact forces by up to approximately 50 per cent. Remarkably, hummingbirds hovered well even under heavy precipitation (i.e. 270 mm h−1) with no apparent loss of control, although mechanical power output assuming perfect and zero storage of elastic energy was estimated to be about 9 and 57 per cent higher, respectively, compared with normal hovering. PMID:22810431

Compensation of thermal constraints along a natural environmental gradient in a Malagasy iguanid lizard (Oplurus quadrimaculatus).

PubMed

Theisinger, Ole; Berg, W; Dausmann, K H

2017-08-01

Physiological or behavioural adjustments are a prerequisite for ectotherms to cope with different thermal environments. One of the world's steepest environmental gradients in temperature and precipitation can be found in southeastern Madagascar. This unique gradient allowed us to study the compensation of thermal constraints in the heliothermic lizard Oplurus quadrimaculatus on a very small geographic scale. The lizard occurs from hot spiny forest to intermediate gallery and transitional forest to cooler rain forest and we investigated whether these habitat differences are compensated behaviourally or physiologically. To study activity skin temperature (as proxy for body temperature) and the activity time of lizards, we attached temperature loggers to individuals in three different habitats. In addition, we calculated field resting costs from field resting metabolic rate to compare energy expenditure along the environmental gradient. We found no variation in activity skin temperature, despite significant differences in operative environmental temperature among habitats. However, daily activity time and field resting costs were reduced by 35% and 28% in the cool rain forest compared to the hot spiny forest. Our study shows that O. quadrimaculatus relies on behavioural mechanisms rather than physiological adjustments to compensate thermal differences between habitats. Furthermore, its foraging activity in open, sun exposed habitats facilitates such a highly effective thermoregulation that cold operative temperature, not energetically expensive heat, presents a greater challenge for these lizards despite living in a hot environment. Copyright © 2017. Published by Elsevier Ltd.

Nitrogen and phosphorus resorption in a neotropical rain forest of a nutrient-rich soil.

PubMed

Martínez-Sánchez, José Luis

2005-01-01

In tropical forests with nutrient-rich soil tree's nutrient resorption from senesced leaves has not always been observed to be low. Perhaps this lack of consistence is partly owing to the nutrient resorption methods used. The aim of the study was to analyse N and P resorption proficiency from tropical rain forest trees in a nutrient-rich soil. It was hypothesised that trees would exhibit low nutrient resorption in a nutrient-rich soil. The soil concentrations of total N and extractable P, among other physical and chemical characteristics, were analysed in 30 samples in the soil surface (10 cm) of three undisturbed forest plots at 'Estaci6n de Biologia Los Tuxtlas' on the east coast of Mexico (18 degrees 34' - 18 degrees 36' N, 95 degrees 04' - 95 degrees 09' W). N and P resorption proficiency were determined from senescing leaves in 11 dominant tree species. Nitrogen was analysed by microkjeldahl digestion with sulphuric acid and distilled with boric acid, and phosphorus was analysed by digestion with nitric acid and perchloric acid. Soil was rich in total N (0.50%, n = 30) and extractable P (4.11 microg g(-1) n = 30). As expected, trees showed incomplete N (1.13%, n = 11) and P (0.11%, n = 1) resorption. With a more accurate method of nutrient resorption assessment, it is possible to prove that a forest community with a nutrient-rich soil can have low levels of N and P resorption.

Current and Future Carbon Budgets of Tropical Rain Forest: A Cross Scale Analysis. Final Report

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

Oberbauer, S. F.

2004-01-16

The goal of this project was to make a first assessment of the major carbon stocks and fluxes and their climatic determinants in a lowland neotropical rain forest, the La Selva Biological Station, Costa Rica. Our research design was based on the concurrent use of several of the best available approaches, so that data could be cross-validated. A major focus of our effort was to combine meteorological studies of whole-forest carbon exchange (eddy flux), with parallel independent measurements of key components of the forest carbon budget. The eddy flux system operated from February 1998 to February 2001. To obtain fieldmore » data that could be scaled up to the landscape level, we monitored carbon stocks, net primary productivity components including tree growth and mortality, litterfall, woody debris production, root biomass, and soil respiration in a series of replicated plots stratified across the major environmental gradients of the forest. A second major focus of this project was on the stocks and changes of carbon in the soil. We used isotope studies and intensive monitoring to investigate soil organic stocks and the climate-driven variation of soil respiration down the soil profile, in a set of six 4m deep soil shafts stratified across the landscape. We measured short term tree growth, climate responses of sap flow, and phenology in a suite of ten canopy trees to develop individual models of tree growth to daytime weather variables.« less

Modeled effects of soil acidification on long-term ecological and economic outcomes for managed forests in the Adirondack region (USA).

PubMed

Caputo, Jesse; Beier, Colin M; Sullivan, Timothy J; Lawrence, Gregory B

2016-09-15

Sugar maple (Acer saccharum) is among the most ecologically and economically important tree species in North America, and its growth and regeneration is often the focus of silvicultural practices in northern hardwood forests. A key stressor for sugar maple (SM) is acid rain, which depletes base cations from poorly-buffered forest soils and has been associated with much lower SM vigor, growth, and recruitment. However, the potential interactions between forest management and soil acidification - and their implications for the sustainability of SM and its economic and cultural benefits - have not been investigated. In this study, we simulated the development of 50 extant SM stands in the western Adirondack region of NY (USA) for 100years under different soil chemical conditions and silvicultural prescriptions. We found that interactions between management prescription and soil base saturation will strongly shape the ability to maintain SM in managed forests. Below 12% base saturation, SM did not regenerate sufficiently after harvest and was replaced mainly by red maple (Acer rubrum) and American beech (Fagus grandifolia). Loss of SM on acid-impaired sites was predicted regardless of whether the shelterwood or diameter-limit prescriptions were used. On soils with sufficient base saturation, models predicted that SM will regenerate after harvest and be sustained for future rotations. We then estimated how these different post-harvest outcomes, mediated by acid impairment of forest soils, would affect the potential monetary value of ecosystem services provided by SM forests. Model simulations indicated that a management strategy focused on syrup production - although not feasible across the vast areas where acid impairment has occurred - may generate the greatest economic return. Although pollution from acid rain is declining, its long-term legacy in forest soils will shape future options for sustainable forestry and ecosystem stewardship in the northern hardwood forests of North America. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Modeled effects of soil acidification on long-term ecological and economic outcomes for managed forests in the Adirondack region (USA)

USGS Publications Warehouse

Caputo, Jesse PhD.; Beier, Colin M.; Sullivan, Timothy J.; Lawrence, Gregory B.

2016-01-01

Sugar maple (Acer saccharum) is among the most ecologically and economically important tree species in North America, and its growth and regeneration is often the focus of silvicultural practices in northern hardwood forests. A key stressor for sugar maple (SM) is acid rain, which depletes base cations from poorly-buffered forest soils and has been associated with much lower SM vigor, growth, and recruitment. However, the potential interactions between forest management and soil acidification – and their implications for the sustainability of SM and its economic and cultural benefits – have not been investigated. In this study, we simulated the development of 50 extant SM stands in the western Adirondack region of NY (USA) for 100 years under different soil chemical conditions and silvicultural prescriptions. We found that interactions between management prescription and soil base saturation will strongly shape the ability to maintain SM in managed forests. Below 12% base saturation, SM did not regenerate sufficiently after harvest and was replaced mainly by red maple (Acer rubrum) and American beech (Fagus grandifolia). Loss of SM on acid-impaired sites was predicted regardless of whether the shelterwood or diameter-limit prescriptions were used. On soils with sufficient base saturation, models predicted that SM will regenerate after harvest and be sustained for future rotations. We then estimated how these different post-harvest outcomes, mediated by acid impairment of forest soils, would affect the potential monetary value of ecosystem services provided by SM forests. Model simulations indicated that a management strategy focused on syrup production – although not feasible across the vast areas where acid impairment has occurred – may generate the greatest economic return. Although pollution from acid rain is declining, its long-term legacy in forest soils will shape future options for sustainable forestry and ecosystem stewardship in the northern hardwood forests of North America.

Paleoecological Calibration In Central Guatemala: Modern Pollen Rain From Bryophyte Polsters And Surface Sediments

NASA Astrophysics Data System (ADS)

Finkelstein, S. A.; Avendano, C. E.; Cowling, S. A.

2009-05-01

Paleoecology requires understanding the correspondences between modern pollen rain and local-regional vegetation, in order to develop accurate paleovegetation reconstructions. Paleoecology in Guatemala has been developed largely over decades in the northern lowlands in close relationship with Classic Maya archaeology, where paleoenvironmental reconstructions have been made mainly through the use of fossil pollen. Scarcity of calibration studies in the Mesoamerican region however remains evident; nevertheless, they are necessary to produce reliable reconstructions. We present calibration pollen data from two locations in Central Guatemala: Lachua Lowlands and Purulha Highlands. Pollen spectra were analyzed from surface sediments samples (SS) from a lake and a small pond in Lachua, a river floodplain and a lake shore in Purulha. Bryophyte polsters samples (BP) were collected from the interior of minimally disturbed forests in both Lachua (rain forest) and Purulha (cloud forest). Pollen spectra between SS and BP differed in both locations. Analysis per location indicates that SS were more similar for Purulha, as compared to Lachua. Combined analysis of locations indicates that SS from both locations were related to anemophilous taxa - great production of pollen quantities that has high dispersion capacities-. This provides evidence that the pollen signal from SS is probably more regional than local. BP from Lachua and Purulha differed notably in their pollen signal, each location containing local taxa, tropical and temperate respectively. Some temperate anemophilous taxa were better represented in Lachua than in Purulha. Purulha SS were similar, and contained more taxa related to disturbance and anemophilous taxa. The arboreal pollen (AP) to non-arboreal (NAP) ratio (AP/NAP) of both SS and BP corresponded with the tree- prevalent landscape in Lachua. The SS AP/NAP ratio represented the deforested landscape of the river floodplain and lake environments in Purulha, while for BP the extensive forest cover from the cloud forest was represented. Comparison of SS with BP provides foundation to understand better the pollen signal recorded in the sedimentary record, since BP pollen signal bring information about what is not represented. The calibration analysis that we present brings in-depth exploration of pollen-vegetation relationships and represents an important contribution for paleoecological research in Guatemala.

Deuterium excess reveals diurnal sources of water vapor in forest air.

PubMed

Lai, Chun-Ta; Ehleringer, James R

2011-01-01

An understanding of atmospheric water vapor content and its isotopic composition is important if we are to be able to model future water vapor dynamics and their potential feedback on future climate change. Here we present diurnal and vertical patterns of water isotope ratios in forest air (δ(2)H(v) and δ(18)O(v)) not observed previously. Water vapor observed at three heights over 3 consecutive days in a coniferous forest in the Pacific Northwest of the United States, shows a stratified nocturnal structure of δ(2)H(v) and δ(18)O(v), with the most positive values consistently observed above the canopy (60 m). Differences between 0.5 m and 60 m range between 2-6‰ for δ(18)O and 20-40‰ for δ(2)H at night. Using a box model, we simulated H(2)O isotope fluxes and showed that the low to high δ(2)H(v) and δ(18)O(v) profiles can be explained by the vapor flux associated with evaporation from the forest floor and canopy transpiration. We used d-excess as a diagnostic tracer to identify processes that contribute to the diurnal variation in atmospheric moisture. Values of d-excess derived from water vapor measurements showed a repeated diel pattern, with the lowest values occurring in the early morning and the highest values occurring at midday. The isotopic composition of rain water, collected during a light rain event in the first morning of our experiment, suggested that considerable below-cloud secondary evaporation occurred during the descent of raindrops. We conclude that atmospheric entrainment appears to drive the isotopic variation of water vapor in the early morning when the convective boundary layer rapidly develops, while evapotranspiration becomes more important in the mid-afternoon as a primary moisture source of water vapor in this forest. Our results demonstrate the interplay between the effects of vegetation and boundary layer mixing under the influence of rain evaporation, which has implications for larger-scale predictions of precipitation across the terrestrial landscape.

Forest ecosystem services: Provisioning of non-timber forest products

Treesearch

James L. Chamberlain; Gregory E. Frey; C. Denise Ingram; Michael G. Jacobson; Cara Meghan Starbuck Downes

2017-01-01

The purpose of this chapter is to describe approaches to calculate a conservative and defensible estimate of the marginal value of forests for non-timber forest products (NTFPs). 'Provisioning" is one of four categories of benefits, or services that ecosystems provide to humans and was described by the Millennium Ecosystem Assessment as 'products...

Radar Mosaic of Africa

NASA Technical Reports Server (NTRS)

1999-01-01

This is an image of equatorial Africa, centered on the equator at longitude 15degrees east. This image is a mosaic of almost 4,000 separate images obtained in 1996 by the L-band imaging radar onboard the Japanese Earth Resources Satellite. Using radar to penetrate the persistent clouds prevalent in tropical forests, the Japanese Earth Resources Satellite was able for the first time to image at high resolution this continental scale region during single flooding seasons. The area shown covers about 7.4 million square kilometers (2.8 million square miles) of land surface, spans more than 5,000 kilometers(3,100 miles) east and west and some 2,000 kilometers (1,240 miles) north and south. North is up in this image. At the full resolution of the mosaic (100 meters or 330 feet), this image is more than 500 megabytes in size, and was processed from imagery totaling more than 60 gigabytes.

Central Africa was imaged twice in 1996, once between January and March, which is the major low-flood season in the Congo Basin, and once between October and November, which is the major high-flood season in the Congo Basin. The red color corresponds to the data from the low-flood season, the green to the high-flood season, and the blue to the 'texture' of the low-flood data. The forests appear green as a result, the flooded and palm forests, as well as urban areas, appear yellow, the ocean and lakes appear black, and savanna areas appear blue, black or green, depending on the savanna type, surface topography and other factors. The areas of the image that are black and white were mapped only between January and March 1996. In these areas, the black areas are savanna or open water, the gray are forests, and the white areas are flooded forests or urban areas. The Congo River dominates the middle of the image, where the nearby forests that are periodically flooded by the Congo and its tributaries stand out as yellow. The Nile River flows north from Lake Victoria in the middle right of the color portion of the mosaic.

This image is one of the products resulting from the Global Rain Forest Mapping project, a joint project between the National Space Development Agency of Japan, the Space Applications Institute of the Joint Research Centre of the European Commission, NASA's Jet Propulsion Laboratory and an international team of scientists. The goal of the Global Rain Forest Mapping mission is to map with the Japanese Earth Resources Satellite the world's tropical rain forests. The Japanese satellite was launched in 1992 by the National Space Development Agency of Japan and the Japanese Ministry of International Trade and Industry, with support from the Remote Sensing Technology Center of Japan.

Characterizing the Phylogenetic Tree Community Structure of a Protected Tropical Rain Forest Area in Cameroon

PubMed Central

Munoz, François; Couteron, Pierre; Hardy, Olivier J.; Sonké, Bonaventure

2014-01-01

Tropical rain forests, the richest terrestrial ecosystems in biodiversity on Earth are highly threatened by global changes. This paper aims to infer the mechanisms governing species tree assemblages by characterizing the phylogenetic structure of a tropical rain forest in a protected area of the Congo Basin, the Dja Faunal Reserve (Cameroon). We re-analyzed a dataset of 11538 individuals belonging to 372 taxa found along nine transects spanning five habitat types. We generated a dated phylogenetic tree including all sampled taxa to partition the phylogenetic diversity of the nine transects into alpha and beta components at the level of the transects and of the habitat types. The variation in phylogenetic composition among transects did not deviate from a random pattern at the scale of the Dja Faunal Reserve, probably due to a common history and weak environmental variation across the park. This lack of phylogenetic structure combined with an isolation-by-distance pattern of taxonomic diversity suggests that neutral dispersal limitation is a major driver of community assembly in the Dja. To assess any lack of sensitivity to the variation in habitat types, we restricted the analyses of transects to the terra firme primary forest and found results consistent with those of the whole dataset at the level of the transects. Additionally to previous analyses, we detected a weak but significant phylogenetic turnover among habitat types, suggesting that species sort in varying environments, even though it is not predominating on the overall phylogenetic structure. Finer analyses of clades indicated a signal of clustering for species from the Annonaceae family, while species from the Apocynaceae family indicated overdispersion. These results can contribute to the conservation of the park by improving our understanding of the processes dictating community assembly in these hyperdiverse but threatened regions of the world. PMID:24936786

Soil Type Has a Stronger Role than Dipterocarp Host Species in Shaping the Ectomycorrhizal Fungal Community in a Bornean Lowland Tropical Rain Forest

PubMed Central

Essene, Adam L.; Shek, Katherine L.; Lewis, J. D.; Peay, Kabir G.; McGuire, Krista L.

2017-01-01

The role that mycorrhizal fungal associations play in the assembly of long-lived tree communities is poorly understood, especially in tropical forests, which have the highest tree diversity of any ecosystem. The lowland tropical rain forests of Southeast Asia are characterized by high levels of species richness within the family Dipterocarpaceae, the entirety of which has been shown to form obligate ectomycorrhizal (ECM) fungal associations. Differences in ECM assembly between co-occurring species of dipterocarp have been suggested, but never tested in adult trees, as a mechanism for maintaining the coexistence of closely related tree species in this family. Testing this hypothesis has proven difficult because the assembly of both dipterocarps and their ECM associates co-varies with the same edaphic variables. In this study, we used high-throughput DNA sequencing of soils and Sanger sequencing of root tips to evaluate how ECM fungi were structured within and across a clay–sand soil nutrient ecotone in a mixed-dipterocarp rain forest in Malaysian Borneo. We compared assembly patterns of ECM fungi in bulk soil to ECM root tips collected from three ecologically distinct species of dipterocarp. This design allowed us to test whether ECM fungi are more strongly structured by soil type or host specificity. As with previous studies of ECM fungi on this plot, we observed that clay vs. sand soil type strongly structured both the bulk soil and root tip ECM fungal communities. However, we also observed significantly different ECM communities associated with two of the three dipterocarp species evaluated on this plot. These results suggest that ECM fungal assembly on these species is shaped by a combination of biotic and abiotic factors, and that the soil edaphic niche occupied by different dipterocarp species may be mediated by distinct ECM fungal assemblages. PMID:29163567

N2O Source Strength of Tropical Rain Forests: From the Site to the Global Scale

NASA Astrophysics Data System (ADS)

Kiese, R.; Werner, C.; Butterbach-Bahl, K.

2006-12-01

In contrast to the significant importance of tropical rain forest ecosystems as one of the major single sources within the global atmospheric N2O budget (2.2 3.7 Tg N y-1, regional and global estimates of their N2O source strength are still limited and highly uncertain. However, accurate quantification of sources and sinks of greenhouse gases like CO2, N2O and CH4 for natural, agricultural and forest ecosystems is crucial to our understanding of land use change effects on global climate change. At present, up-scaling approaches which link detailed geographic information systems (GIS) to mechanistic biochemical models are seen as a promising tool to contribute towards more reliable estimates of biogenic sources of N2O, e.g. tropical rain forest ecosystems. In our study we further developed and tested the PnET-N-DNDC model using Bayesian calibration techniques based on detailed N2O emission data of two recently conducted field campaigns in African (Kenya) and Asian (SE-China) tropical forest ecosystems and additional datasets from earlier own field campaigns or the literature. For global upscaling of N2O emissions an extensive GIS database was constructed holding all necessary parameters (climate ECWMF ERA 40; soil: FAO, vegetation: LPJ-DGVM simulation) in spatial and temporal resolution for initializing and driving the further developed biogeochemical model at a grid size of 0.25°x0.25°. We calculated global N2O emissions inventories for the years 1991 to 2001, and found a general agreement of the simulated flux ranges with reported N2O emissions from tropical forest ecosystems worldwide. According to our simulations, tropical rainforest soils are indeed a significant source of atmospheric N2O ranging from 1.1 2.2 Tg in dependence from the simulated year. Notably, related to differences in environmental conditions, N2O emissions varied considerably within the tropical belt. Furthermore, our simulations revealed a pronounced inter-annual variability of N2O emissions mainly driven by differences in weather conditions (e.g. distribution and total amount of rainfall) across years, which may be mirrored in atmospheric N2O concentrations.

Chemical characterization of fog and rain water collected at the eastern Andes cordillera

NASA Astrophysics Data System (ADS)

Beiderwieden, E.; Wrzesinsky, T.; Klemm, O.

2005-09-01

During a three month period in 2003 and 2004, the chemistry of fog and rainwater were studied at the "El Tiro" site in a tropical mountain forest ecosystem in Ecuador, South America. The fogwater samples were collected using a passive fog collector, and for the rain water, a standard rain sampler was employed. For all samples, electric conductivity, pH, and the concentrations of NH4+, K+, Na+, Ca2+, Mg2+, Cl-, NO3-, PO43-, and SO42- were measured. For each fog sample, a 5 day back trajectory was calculated by the use of the HYSPLIT model. Two types of trajectories occurred. One type was characterized by advection of air masses from the East over the Amazonian basin, the other trajectory arrived one from the West after significant travel time over the Pacific Ocean. We found considerably higher ion concentrations in fogwater samples than in rain samples. Median pH values are 4.58 for fog water, and 5.26 for the rain samples, respectively. The median electric conductivity was 23 μS cm-1 for the fog and 6 μS cm-1 for the rain. The continent samples exhibit higher concentrations of most ions as compared to the pacific samples, but these differences could not be detected statistically.

Strategy for the forest sector in sub Saharan Africa. World Bank technical paper; Strategie pour le secteur forestier en afrique subsaharienne

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

Sharma, N.P.; Rietbergen, S.; Heimo, C.R.

1995-12-31

Forest resources in Sub-Saharan Africa are disappearing at an alarming rate--the region witnessed a seven percent loss of its forest cover during the 1980s. The deforestation of tropical rain forests in West and Central Africa is occurring at a rate of two million hectares each year. The poor usually suffer the most in the short run--but it is the entire world community that suffers in the long run from the ensuing ecological damage. This strategy paper is one element of the World Bank`s process of addressing environmental issues and challenges. The paper adheres to the Bank`s forest policy adopted inmore » 1991, which reaffirms the Bank`s support for conservation and sustainable development of forest resources. The authors emphasize the importance of the symbiosis of forest resource management and socioeconomic development for the region.« less

The intermediate disturbance hypothesis applies to tropical forests, but disturbance contributes little to tree diversity.

PubMed

Bongers, Frans; Poorter, Lourens; Hawthorne, William D; Sheil, Douglas

2009-08-01

The intermediate disturbance hypothesis (IDH) predicts local species diversity to be maximal at an intermediate level of disturbance. Developed to explain species maintenance and diversity patterns in species-rich ecosystems such as tropical forests, tests of IDH in tropical forest remain scarce, small-scale and contentious. We use an unprecedented large-scale dataset (2504 one-hectare plots and 331,567 trees) to examine whether IDH explains tree diversity variation within wet, moist and dry tropical forests, and we analyse the underlying mechanism by determining responses within functional species groups. We find that disturbance explains more variation in diversity of dry than wet tropical forests. Pioneer species numbers increase with disturbance, shade-tolerant species decrease and intermediate species are indifferent. While diversity indeed peaks at intermediate disturbance levels little variation is explained outside dry forests, and disturbance is less important for species richness patterns in wet tropical rain forests than previously thought.

Fogwater Inputs to a Cloud Forest in Puerto Rico

NASA Astrophysics Data System (ADS)

Eugster, W.; Burkard, R.; Holwerda, F.; Bruijnzeel, S.; Scatena, F. N.; Siegwolf, R.

2002-12-01

Fog is highly persistent at upper elevations of humid tropical mountains and is an important pathway for water and nutrient inputs to mountain forest ecosystems. Measurements of fogwater fluxes were performed in the Luquillo mountains of Puerto Rico using the eddy covariance approach and a Caltech-type active strand cloudwater collector. Rainfall and throughfall were collected between 25 June--7 August 2002. Samples of fog, rain, stemflow and throughfall were analyzed for inorganic ion and stable isotope concentrations (δ18O and δD). Initial results indicate that fog inputs can occur during periods without rain and last for up to several days. The isotope ratios in rainwater and fogwater are rather similar, indicative of the proximity of the Carribbean Sea and the close interrelation between the origins of fog and rain at our experimental site. Largest differences in isotope ratios for fog were found between daytime convective and nighttime stable conditions. Throughfall was always exceeding rainfall, indicating (a) the relevance of fogwater inputs and (b) the potentially significant undersampling of rainfall due to relatively high wind speeds (5.7 m/s mean) and the exposition of our field site close to a mountain ridge. Our size-resolved measurements of cloud droplets (40 size bins between 2 and 50 μm aerodynamic diameter) indicate that the liquid water content of fog in the Luquillo mountains is 5 times higher than previously assumed, and thus does not differ from the values reported from other mountain ranges in other climate zones. Average deposition rates are 0.88 mm and 6.5 mm per day for fog and rain, respectively.

The Ancient Art of Silk Painting

ERIC Educational Resources Information Center

Yonker, Kim

2010-01-01

In this article, the author describes a silk-painting project with a sea-creature theme for eighth-grade students. Other themes can be used such as geometric quilt designs, tropical rain forest, large flowers, Art Nouveau motifs, portraits and more. (Contains 2 resources.)

Analysis of Interferometric Radar Data in a Queensland, Australia Tropical Rain Forest

NASA Technical Reports Server (NTRS)

Hensley, Scott; Rodriquez, Ernesto; Chapin, Elaine; Accad, Arnon

1999-01-01

The radar flies at 8000 m (24000 ft) above the ground and collects data in swath about 10 km wide. The radar simultaneously collects data from multiple frequencies and is capable of making interferometric radar measurements.

[Acumen function in leaves and its vertical distribution in a tropical rain forest of Costa Rica].

PubMed

Farji-Brener, Alejandro G; Valverde, Oscar; Paolini, Leonardo; de los Angeles La Torre, María; Quintero, Estela; Bonaccorso, Elisa; Arnedo, Luisa; Villalobos, Richard

2002-06-01

Water retention on the leaf surface can be maladaptive to the plant because it increases the colonization of epiphylls and interferes with the physiologic processes of the leaf, diminishing the photosynthetic capacity. To test if leaf driptips facilitate leaf drying after rainfall in a tropical rain forest of Costa Rica, we (1) experimentally measured the capacity to retain water on leaf surfaces of 30 plant species before and after driptip removal, and (2) analyzed the development of driptips along forest strata. We expected leaf driptips to be less developed in the upper strata due to the environmental conditions of the canopy (i.e., high solar radiation, strong winds and low relative humidity), which favor the natural drying of leaves. The presence of driptips increased 100% the water run off capacity of leaves in all the analyzed species. Also, the development of leaf driptips was smaller in canopy species than in understory species. Additionally, they became less developed in canopy species as trees increased in height. These results support the hypothesis that the adaptive role of driptips is to facilitate the drying of leaf surfaces.

Wet canopy evaporation from a Puerto Rican lower montane rain forest: the importance of realistically estimated aerodynamic conductance

Treesearch

F. Holwerda; L.A. Bruijnzeel; F.N. Scatena; H.F. Vugts; A.G.C.A. Meesters

2012-01-01

Rainfall interception (I) was measured in 20 m tall Puerto Rican tropical forest with complex topography for a 1-year period using totalizing throughfall (TF) and stemflow (SF) gauges that were measured every 2–3 days. Measured values were then compared to evaporation under saturated canopy conditions (E) determined with the Penman–Monteith (P–M) equation, using (i)...

Temperate pine barrens and tropical rain forests are both rich in undescribed fungi.

PubMed

Luo, Jing; Walsh, Emily; Naik, Abhishek; Zhuang, Wenying; Zhang, Keqin; Cai, Lei; Zhang, Ning

2014-01-01

Most of fungal biodiversity on Earth remains unknown especially in the unexplored habitats. In this study, we compared fungi associated with grass (Poaceae) roots from two ecosystems: the temperate pine barrens in New Jersey, USA and tropical rain forests in Yunnan, China, using the same sampling, isolation and species identification methods. A total of 426 fungal isolates were obtained from 1600 root segments from 80 grass samples. Based on the internal transcribed spacer (ITS) sequences and morphological characteristics, a total of 85 fungal species (OTUs) belonging in 45 genera, 23 families, 16 orders, and 6 classes were identified, among which the pine barrens had 38 and Yunnan had 56 species, with only 9 species in common. The finding that grass roots in the tropical forests harbor higher fungal species diversity supports that tropical forests are fungal biodiversity hotspots. Sordariomycetes was dominant in both places but more Leotiomycetes were found in the pine barrens than Yunnan, which may play a role in the acidic and oligotrophic pine barrens ecosystem. Equal number of undescribed fungal species were discovered from the two sampled ecosystems, although the tropical Yunnan had more known fungal species. Pine barrens is a unique, unexplored ecosystem. Our finding suggests that sampling plants in such unexplored habitats will uncover novel fungi and that grass roots in pine barrens are one of the major reservoirs of novel fungi with about 47% being undescribed species.

An analysis of modern pollen rain from the Maya lowlands of northern Belize

USGS Publications Warehouse

Bhattacharya, T.; Beach, T.; Wahl, D.

2011-01-01

In the lowland Maya area, pollen records provide important insights into the impact of past human populations and climate change on tropical ecosystems. Despite a long history of regional paleoecological research, few studies have characterized the palynological signatures of lowland ecosystems, a fact which lowers confidence in ecological inferences made from palynological data. We sought to verify whether we could use pollen spectra to reliably distinguish modern ecosystem types in the Maya lowlands of Central America. We collected 23 soil and sediment samples from eight ecosystem types, including upland, riparian, secondary, and swamp (bajo) forests; pine savanna; and three distinct wetland communities. We analyzed pollen spectra with non-metric multidimensional scaling (NMDS), and found significant compositional differences in ecosystem types' pollen spectra. Forested sites had spectra dominated by Moraceae/Urticaceae pollen, while non-forested sites had significant portions of Poaceae, Asteraceae, and Amaranthaceae pollen. Upland, bajo, and riparian forest differed in representation of Cyperaceae, Bactris-type, and Combretaceae/Melastomataceae pollen. High percentages of pine (Pinus), oak (Quercus), and the presence of Byrsonima characterized pine savanna. Despite its limited sample size, this study provides one of the first statistical analyses of modern pollen rain in the Maya lowlands. Our results show that pollen assemblages can accurately reflect differences between ecosystem types, which may help refine interpretations of pollen records from the Maya area. ?? 2010 Elsevier B.V.

The relationship between Anopheles gambiae density and rice cultivation in the savannah zone and forest zone of Côte d'Ivoire.

PubMed

Briët, Olivier J T; Dossou-Yovo, Joel; Akodo, Elena; van de Giesen, Nick; Teuscher, Thomas M

2003-05-01

In 13 villages in the savannah zone and 21 villages in the forest zone of Côte d'Ivoire, the biting density of the principal malaria vector, Anopheles gambiae, was studied as a function of rice cultivation in the inland valleys in a 2-km radius around each village. In the savannah villages, during the main season cropping period, surface water on rice-cultivated and to a lesser extent on uncultivated inland valleys seems to contribute strongly to the A. gambiae population density. For the off-season cropping period (which starts after the first light rains in the savannah zone), correlations were weaker. Breeding sites other than in inland valleys may play an important role in the savannah zone. In the forest zone, however, the A. gambiae population density was strongly correlated with the surface water availability (SWA) in the rice-cultivated inland valleys, whereas the correlation with the SWA in other (uncultivated) inland valleys was weak. The requirement of sunlit breeding sites for A. gambiae might explain this difference between zones. In the forest zone, only inland valleys cleared for rice cultivation meet this requirement, whereas all other inland valleys are covered with dense vegetation. In the savannah zone, however, most undergrowth is burnt during the dry season, which permits sunlight to reach puddles resulting from the first rains.

Ion fluxes from fog and rain to an agricultural and a forest ecosystem in Europe

NASA Astrophysics Data System (ADS)

Thalmann, E.; Burkard, R.; Wrzesinsky, T.; Eugster, W.; Klemm, O.

The deposition fluxes of inorganic compounds dissolved in fog and rain were quantified for two different ecosystems in Europe. The fogwater deposition fluxes were measured by employing the eddy covariance method. The site in Switzerland that lies within an agricultural area surrounded by the Jura mountains and the Alps is often exposed to radiation fog. At the German mountain forest ecosystem, on the other hand, advection fog occurs most frequently. At the Swiss site, fogwater deposition fluxes of the dominant components SO 42- (0.027 mg S m -2 day -1), NO 3- (0.030 mg N m -2 day -1) and NH 4+ (0.060 mg N m -2 day -1) were estimated to be <5% of the measured wet deposition (0.85, 0.70 and 1.34 mg m -2 day -1, respectively). The corresponding fluxes at the forest site (0.62, 0.82 and 1.16 mg m -2 day -1, respectively) were of the same order of magnitude as wet deposition (1.04, 1.01 and 1.36 mg m -2 day -1), illustrating the importance of fog (or occult) deposition. Trajectory analyses at the forest site indicate significantly higher fogwater concentrations of all major ions if air originated from the east (i.e. the Czech Republic), which is in close agreement with earlier studies.

Longer-term effects of selective thinning on microarthropod communities in a late-successional coniferous forest.

Treesearch

Robert W. Peck; Christine G. Niwa

2005-01-01

Microarthropod densities within late-successional coniferous forests thinned 16-41 yr before sampling were compared with adjacent unthinned stands to identify longer term effects of thinning on this community. Soil and forest floor layers were sampled separately on eight paired sites. Within the forest floor oribatid, mesostigmatid, and to a marginal extent,...

Forest seedling production in Israel

Treesearch

Nir Atzmon; David Brand

2002-01-01

Afforestation and reforestation in Israel are done on marginal lands, which consist of poor and shallow soils, with precipitation ranging from 650 mm in the north down to 200 mm in the south. Therefore, seedling quality is of great concern. All forest seedlings planted in Israel are produced by three forest nurseries which belong to the Forest Authority of Israel....

Physiological characteristics of tropical rain forest tree species: A basis for the development of silvicultural technology

PubMed Central

SASAKI, Satohiko

2008-01-01

The physiological characteristics of the dominant tree species in the tropical rain forest mainly belonging to dipterocarps as well as the environmental conditions especially for the light in the forest were studied to establish the silvicultural system for the forest regeneration in the tropical South Asia. The flowering patterns of the dipterocarp trees are usually irregular and unpredictable, which make difficult to collect sufficient seeds for raising the seedlings. The field survey revealed the diverged features of the so-called gregarious or simultaneous flowering of various species of this group. Appropriate conditions and methods for the storage of the seeds were established according to the detailed analyses of the morphological and physiological characteristics of the seeds such as the low temperature tolerance and the moisture contents. The intensity and spectra of the light in the forest primarily determine the growth and the morphological development of the seedlings under the canopy. Based on the measurements of the diffused light at the sites in the tropical forest in the varying sunlight, the parameters such as “the steady state of the diffuse light” and “the turning point” were defined, which were useful to evaluate the light conditions in the forest. To improve the survival of the transplanted seedlings, a planting method of “the bare-root seedlings”, the seedlings easy to be handled by removal of all leaves, soil and pots, was developed. Its marked efficiency was proved with various dipterocarps and other tropical trees by the field trial in the practical scale. Tolerance of the various species to the extreme environmental conditions such as fires, acid soils and drought were examined by the experiments and the field survey, which revealed marked adaptability of Shorea roxburghii as a potential species for regeneration of the tropical forests. PMID:18941286

Evaporation from cultivated and semi-wild Sudanian Savanna in west Africa

NASA Astrophysics Data System (ADS)

Ceperley, Natalie C.; Mande, Theophile; van de Giesen, Nick; Tyler, Scott; Yacouba, Hamma; Parlange, Marc B.

2017-08-01

Rain-fed farming is the primary livelihood of semi-arid west Africa. Changes in land cover have the potential to affect precipitation, the critical resource for production. Turbulent flux measurements from two eddy-covariance towers and additional observations from a dense network of small, wireless meteorological stations combine to relate land cover (savanna forest and agriculture) to evaporation in a small (3.5 km2) catchment in Burkina Faso, west Africa. We observe larger sensible and latent heat fluxes over the savanna forest in the headwater area relative to the agricultural section of the watershed all year. Higher fluxes above the savanna forest are attributed to the greater number of exposed rocks and trees and the higher productivity of the forest compared to rain-fed, hand-farmed agricultural fields. Vegetation cover and soil moisture are found to be primary controls of the evaporative fraction. Satellite-derived vegetation index (NDVI) and soil moisture are determined to be good predictors of evaporative fraction, as indicators of the physical basis of evaporation. Our measurements provide an estimator that can be used to derive evaporative fraction when only NDVI is available. Such large-scale estimates of evaporative fraction from remotely sensed data are valuable where ground-based measurements are lacking, which is the case across the African continent and many other semi-arid areas. Evaporative fraction estimates can be combined, for example, with sensible heat from measurements of temperature variance, to provide an estimate of evaporation when only minimal meteorological measurements are available in remote regions of the world. These findings reinforce local cultural beliefs of the importance of forest fragments for climate regulation and may provide support to local decision makers and rural farmers in the maintenance of the forest areas.

Fungal community composition in neotropical rain forests: the influence of tree diversity and precipitation.

PubMed

McGuire, Krista L; Fierer, Noah; Bateman, Carling; Treseder, Kathleen K; Turner, Benjamin L

2012-05-01

Plant diversity is considered one factor structuring soil fungal communities because the diversity of compounds in leaf litter might determine the extent of resource heterogeneity for decomposer communities. Lowland tropical rain forests have the highest plant diversity per area of any biome. Since fungi are responsible for much of the decomposition occurring in forest soils, understanding the factors that structure fungi in tropical forests may provide valuable insight for predicting changes in global carbon and nitrogen fluxes. To test the role of plant diversity in shaping fungal community structure and function, soil (0-20 cm) and leaf litter (O horizons) were collected from six established 1-ha forest census plots across a natural plant diversity gradient on the Isthmus of Panama. We used 454 pyrosequencing and phospholipid fatty acid analysis to evaluate correlations between microbial community composition, precipitation, soil nutrients, and plant richness. In soil, the number of fungal taxa increased significantly with increasing mean annual precipitation, but not with plant richness. There were no correlations between fungal communities in leaf litter and plant diversity or precipitation, and fungal communities were found to be compositionally distinct between soil and leaf litter. To directly test for effects of plant species richness on fungal diversity and function, we experimentally re-created litter diversity gradients in litter bags with 1, 25, and 50 species of litter. After 6 months, we found a significant effect of litter diversity on decomposition rate between one and 25 species of leaf litter. However, fungal richness did not track plant species richness. Although studies in a broader range of sites is required, these results suggest that precipitation may be a more important factor than plant diversity or soil nutrient status in structuring tropical forest soil fungal communities.

Comparison of microclimate in various land-use systems in Sumatra, Indonesia

NASA Astrophysics Data System (ADS)

Shekhar Badu, Chandra; Meijide, Ana; Gunawan, Dodo; Knohl, Alexander

2017-04-01

Deforestation and land-use changes are ongoing problems for rain forests in Indonesia. The conversion of forests to monocultures of rubber and oil palm plantations reduces not only biodiversity and carbon pools but also affects canopy structure, which is an important determinant of microclimate. There is, however, a lack of quantitative information characterizing the effect of land transformation on microclimate with a systematic experimental design. Here, we report observations microclimatic conditions (air temperature, relative humidity, soil moisture and soil temperature) on a daily, weekly and seasonal basis across four land-use systems (rain forest, jungle rubber, rubber plantation, oil palm plantation) in two near-by landscapes. The data set covers a period of approximately three years from April 2013 to March 2016 and includes one of the strongest El Nino-Southern Oscillation (ENSO) of the last decades. Mean air temperature, soil temperature, relative humidity, and vapour pressure deficit differed significantly between the four land-use systems whereas the mean soil moisture differed significantly between two landscapes. Air temperature, vapour pressure deficit and soil temperature were highest in oil palm and rubber plantations whereas lowest in forest and jungle rubber. Canopy openness was the most dominant control of microclimatic differences across the land-use systems. During the ENSO 2015, a significant increase in mean air temperature, soil temperature and vapour pressure deficit but a decrease in relative air humidity and soil moisture in all four land-use systems was found. The relative effect of ENSO was highest in forest and jungle rubber compared to rubber and oil palm plantations. In conclusion, conversion of forest to rubber and oil palm plantations has led to substantially warmer and drier microclimatic conditions than before.

Emissions Of Forest Fires In The Amazon: Impact On The Tropical Mountain Forest In Ecuador

NASA Astrophysics Data System (ADS)

Fabian, P.; Rollenbeck, R.; Thiemens, M. H.; Brothers, L.

2006-12-01

Biomass burning is a source of carbon, sulphur, and nitrogen compounds which, along with their photochemically generated reaction products, can be transported over very large distances, even traversing oceans. Four years of regular rain and fog-water measurements in the tropical mountain forest at the eastern slopes of the Ecuadorian Andes, along an altitude profile between 1800 m and 3185 m, have been carried out. The ion composition of rain and fog-water samples shows frequent episodes of significantly enhanced nitrogen and sulphur, resulting in annual deposition rates of about 5 kg N/ha and 10 kg S/ha into this ecosystem, which are comparable to those of polluted central Europe. By relating back trajectories calculated by means of the FLEXTRA model to the distributions of satellite derived forest fire pixels, it can be shown that most episodes of enhanced ion concentration, with pH values as low as 4.0, can be attributed to biomass burning in the Amazon. First analyses of oxygen isotopes 16O, 17O, and 18O of nitrate in fogwater samples show mass independent fractionation values ranging between 15 and 20 per mille, clearly indicating that nitrate in the samples is a product of atmospheric conversion of precursors, while the isotope data of river samples taken downstream of the research area are grouped in the region of microbial nitrate. This strongly supports the aforementioned trajectory results and shows that the tropical mountain forest in Ecuador, with local pollution sources missing,is "fertilized" by long-range transport of substances originating from forest fires in Colombia, Venezuela, Brazil, and Peru, far upwind of the research site.

Tree fern trunks facilitate seedling regeneration in a productive lowland temperate rain forest.

PubMed

Gaxiola, Aurora; Burrows, Larry E; Coomes, David A

2008-03-01

Seedling regeneration on forest floors is often impaired by competition with established plants. In some lowland temperate rain forests, tree fern trunks provide safe sites on which tree species establish, and grow large enough to take root in the ground and persist. Here we explore the competitive and facilitative effects of two tree fern species, Cyathea smithii and Dicksonia squarrosa, on the epiphytic regeneration of tree species in nutrient-rich alluvial forests in New Zealand. The difficulties that seedlings have in establishing on vertical tree fern trunks were indicated by the following observations. First, seedling abundance was greatest on the oldest sections of tree fern trunks, near the base, suggesting that trunks gradually recruited more and more seedlings over time, but many sections of trunk were devoid of seedlings, indicating the difficulty of establishment on a vertical surface. Second, most seedlings were from small-seeded species, presumably because smaller seeds can easily lodge on tree fern trunks. Deer browsing damage was observed on 73% of epiphytic seedlings growing within 2 m of the ground, whereas few seedlings above that height were browsed. This suggests that tree ferns provide refugia from introduced deer, and may slow the decline in population size of deer-preferred species. We reasoned that tree ferns would compete with epiphytic seedlings for light, because below the tree fern canopy photosynthetically active radiation (PAR) was about 1% of above-canopy PAR. Frond removal almost tripled %PAR on the forest floor, leading to a significant increase in the height growth rate (HGR) of seedlings planted on the forest floor, but having no effects on the HGRs of epiphytic seedlings. Our study shows evidence of direct facilitative interactions by tree ferns during seedling establishment in plant communities associated with nutrient-rich soils.

Terrain Analysis Procedural Guide for Climate,

DTIC Science & Technology

1980-09-01

such as the Amazon Tropical Rain Forest Basin and the Congo Basin, the air is IN Singapore F always hot and damp, there are fre-30...to protect certain mele-annual evaporation rate. These lands are orological instruments from exposure tocharacterized by rainforest , jungle, and

Effects of application of sulphuric acid to poor pine forests

Treesearch

C. O. Tamm; G. Wiklander; B. Popovic

1976-01-01

The department of plant ecology and soils of the College of Forestry has been interested in the problem of the acid rain as an environmental factor since the discussion of this problem started in the late 1960's (0den 1968).

Paludified forests of Komi Republic (Northeastern Europe) do not act as hotspots of the CH4 emissions

NASA Astrophysics Data System (ADS)

Schneider, Julia; Lukasheva, Maria; Gudyrev, Vasiliy; Miglovets, Mikhail

2017-04-01

In the Komi Republic, which is situated in Northeastern Europe and is subject of Russian Federation, 306,000km2 or about 73 % of the total area are covered by forest. The predominant part of these forests lies within the boreal zone. Within the boreal forests the vegetation patterns are a result of the moisture characteristics and air temperature. Based on the moisture conditions forest communities can be grouped into wet, mesic and dry sites. In conditions of high soil moisture content forest peatlands can develop. In boreal forest landscapes it is not a rare phenomenon and can reach coverage of up to one third of the total area. In addition to the high water content of the soils forested peatlands are characterised by low soil temperatures, high organic matter accumulation and low organic matter decomposition. The thick moss-organic layer on the forest floor and waterlogged soils favours methanogenesis. Such process of accumulation of poorly decomposed organic matter mostly originating from Sphagnum which involves the formation of waterlogged conditions is defined as paludification. Highly favourable to forest paludification are sites characterised by fine-textured soils which highly hamper percolation. Paludified forests also occur at peatland margins as a result of peatland expansion. During the last years peatland margins were considered as potential biogeochemical hotspots within the peatlands and due to their high nutrient and dissolved organic matter content they may also be a major methane emitter. Paludification can also occur at forests sites after clear cutting, which is a very intensive logging type and usually leads to water table elevations. In this study measurements were conducted at peatland margins and at a clear cut sites during three climatically different years. The summer of the year 2013 was considerably warmer and drier, and the summer of the year 2014 was considerably colder and wetter than the long term mean. The investigation period in 2015 was characterised by warm and dry spring and early summer, July was colder and very dry, and from August on the weather in the region was colder and wetter than the mean. In this study we show, that regardless of the weather conditions and the water table levels related thereto, the peatland margins did not act as strong methane emitter but are mostly sources of methane and the clear cut sites emit very small amounts of methane or are even sinks for atmospheric methane.

The Chesapeake Bay bolide impact: a new view of coastal plain evolution

USGS Publications Warehouse

Poag, C. Wylie

1998-01-01

A spectacular geological event took place on the Atlantic margin of North America about 35 million years ago in the late part of the Eocene Epoch. Sea level was unusually high everywhere on Earth, and the ancient shoreline of the Virginia region was somewhere in the vicinity of where Richmond is today (fig. 1). Tropical rain forests covered the slopes of the Appalachians. To the east of a narrow coastal plain, a broad, lime (calcium carbonate)- covered continental shelf lay beneath the ocean. Suddenly, with an intense flash of light, that tranquil scene was transformed into a hellish cauldron of mass destruction. From the far reaches of space, a bolide (comet or asteroid), 3-5 kilometers in diameter, swooped through the Earth's atmosphere and blasted an enormous crater into the continental shelf. The crater is now approximately 200 km southeast of Washington, D.C., and is buried 300-500 meters beneath the southern part of Chesapeake Bay and the peninsulas of southeastern Virginia (fig. 1). The entire bolide event, from initial impact to the termination of breccia deposition, lasted only a few hours or days. The crater was then buried by additional sedimentary beds, which accumulated during the following 35 million years.

Rain shadow development and paleoenvironmental change in the southern Central Anatolian Plateau

NASA Astrophysics Data System (ADS)

Meijers, Maud J. M.; Mulch, Andreas; Brocard, Gilles Y.; Whitney, Donna L.

2015-04-01

Ongoing Arabia-Eurasia convergence in the eastern Mediterranean region has led to the westward escape of the Anatolian microplate and the formation of the Central Anatolian Plateau (CAP). The US-NSF CD-CAT (Continental Dynamics-Central Anatolian Tectonics) project aims at understanding the surface-to-mantle coupling during the transition from collision to escape tectonics and plateau formation in Anatolia. Within the CD-CAT project, this study aims at determining the paleoenvironmental conditions and the age of plateau (margin) uplift by integrating stable isotope geochemistry and absolute dating techniques (40Ar/39Ar geochronology and magnetostratigraphy) on middle Miocene to Pliocene lacustrine sedimentary rocks. The low-relief CAP (~1.5 km average elevation) is characterized by high-relief mountain ranges at its southern and northern margins. The Tauride mountain belt forms the southern plateau margin of the CAP with a relief of up to 3 km. Uplift of Tortonian marine sediments in the central Taurides to modern elevations of up to 2 km constrain the onset of surface uplift of the southern plateau margin to ~8 Ma (Schildgen et al. 2012a,b). Proxy records of oxygen isotopes (δ18O) in precipitation allow to reconstruct the development of the present-day Tauride rain shadow and hence the surface elevation history of the southern plateau margin. Here we evaluate δ18O and δ13C records of seven lacustrine basins situated along a SW-NE swath in the lee of the modern Tauride mountains in order to track the development of a Tauride rain shadow and changes in open to closed lake conditions through the late Miocene to Pliocene. We focus on lacustrine sections with available mammal ages and integrate these with 40Ar/39Ar geochronology of widespread volcanics of the Central Anatolian Volcanic Province and magnetostratigraphy where possible. Our results from seven sections of ~12-4 Ma in lacustrine deposits and pedogenic soil carbonates of ~3-2.5 Ma show a decrease of δ18O values between ~12 and ~6 Ma of ca. 3o followed by a period of remarkably stable δ18O values around 21.5o until about 2.5 Ma. The latter coincides with modern δ18O values of the least-evaporative rinds of modern pedogenic carbonate. The observed 3o decrease in δ18O of lacustrine carbonate accounts for about 50 % of the present-day effect of orographic rainout on δ18O of precipitation (Schemmel et al. 2013) along the southern plateau margin. This might indicate the presence of a ~1000m high plateau prior to the formation of the Tauride chain. Schildgen et al., EPSL 317-118, 2012a; Schildgen et al., Tectonics 31, 2012b; Schemmel et al., AJS 313, 2013

Expression pattern of four storage xyloglucan mobilization-related genes during seedling development of the rain forest tree Hymenaea courbaril L.

PubMed

Brandão, A D; Del Bem, L E V; Vincentz, M; Buckeridge, M S

2009-01-01

During seedling establishment, cotyledons of the rain forest tree Hymenaea courbaril mobilize storage cell wall xyloglucan to sustain growth. The polysaccharide is degraded and its products are transported to growing sink tissues. Auxin from the shoot controls the level of xyloglucan hydrolytic enzymes. It is not yet known how important the expression of these genes is for the control of storage xyloglucan degradation. In this work, partial cDNAs of the genes xyloglucan transglycosylase hydrolase (HcXTH1) and beta-galactosidase (HcBGAL1), both related to xyloglucan degradation, and two other genes related to sucrose metabolism [alkaline invertase (HcAlkIN1) and sucrose synthase (HcSUS1)], were isolated. The partial sequences were characterized by comparison with sequences available in the literature, and phylogenetic trees were assembled. Gene expression was evaluated at intervals of 6 h during 24 h in cotyledons, hypocotyl, roots, and leaves, using 45-d-old plantlets. HcXTH1 and HcBGAL1 were correlated to xyloglucan degradation and responded to auxin and light, being down-regulated when transport of auxin was prevented by N-1-naphthylphthalamic acid (NPA) and stimulated by constant light. Genes related to sucrose metabolism, HcAlkIN1 and HcSUS1, responded to inhibition of auxin transport in consonance with storage mobilization in the cotyledons. A model is proposed suggesting that auxin and light are involved in the control of the expression of genes related to storage xyloglucan mobilization in seedlings of H. courbaril. It is concluded that gene expression plays a role in the control of the intercommunication system of the source-sink relationship during seeding growth, favouring its establishment in the shaded environment of the rain forest understorey.

Expression pattern of four storage xyloglucan mobilization-related genes during seedling development of the rain forest tree Hymenaea courbaril L.

PubMed Central

Brandão, A. D.; Del Bem, L. E. V.; Vincentz, M.; Buckeridge, M. S.

2009-01-01

During seedling establishment, cotyledons of the rain forest tree Hymenaea courbaril mobilize storage cell wall xyloglucan to sustain growth. The polysaccharide is degraded and its products are transported to growing sink tissues. Auxin from the shoot controls the level of xyloglucan hydrolytic enzymes. It is not yet known how important the expression of these genes is for the control of storage xyloglucan degradation. In this work, partial cDNAs of the genes xyloglucan transglycosylase hydrolase (HcXTH1) and β-galactosidase (HcBGAL1), both related to xyloglucan degradation, and two other genes related to sucrose metabolism [alkaline invertase (HcAlkIN1) and sucrose synthase (HcSUS1)], were isolated. The partial sequences were characterized by comparison with sequences available in the literature, and phylogenetic trees were assembled. Gene expression was evaluated at intervals of 6 h during 24 h in cotyledons, hypocotyl, roots, and leaves, using 45-d-old plantlets. HcXTH1 and HcBGAL1 were correlated to xyloglucan degradation and responded to auxin and light, being down-regulated when transport of auxin was prevented by N-1-naphthylphthalamic acid (NPA) and stimulated by constant light. Genes related to sucrose metabolism, HcAlkIN1 and HcSUS1, responded to inhibition of auxin transport in consonance with storage mobilization in the cotyledons. A model is proposed suggesting that auxin and light are involved in the control of the expression of genes related to storage xyloglucan mobilization in seedlings of H. courbaril. It is concluded that gene expression plays a role in the control of the intercommunication system of the source–sink relationship during seeding growth, favouring its establishment in the shaded environment of the rain forest understorey. PMID:19221141

From where does the Amazon forest gets its water?

NASA Astrophysics Data System (ADS)

Miguez-Macho, G.; Fan, Y.

2016-12-01

The Amazon receives abundant annual rainfall but parts of it experience a multi-month dry season. Here we ask: what is the water source that sustains the dry-season ET? Where over the Amazon it is largely local and recent rain (hence ET shutting down in dry season), or past rain that is stored in the deep soils and the groundwater (deep roots tapping deep reservoirs sustaining ET), or is it rain that fell on higher grounds (through topography-driven lateral convergence)? Using synthesis of isotope and other tracer observations and basin-wide inverse modeling (shallow soil, deep soil, with and without groundwater, with and without dynamic rooting depth), we attempt to tease out these components. The results shed light on likely ET sources and how future global change may preferentially impact Amazon ecosystem functioning.

Complex Spatial Structure in a Population of Didymopanax pittieri, A Tree of Wind-Exposed Lower Montane Rain Forest

NASA Technical Reports Server (NTRS)

Lawton, Robert M.; Lawton, Robert O.

2010-01-01

Didymopanax pittieri is a common shade-intolerant tree colonizing treefall gaps in the elfin forests on windswept ridgecrests in the lower montane rain forests of the Cordillera de Tilarain, Costa Rica. All D. pittieri taller than > 0.5 m in a 5.2-ha elfin forested portion of a gridded study watershed in the Monteverde Cloud Forest Preserve were located, mapped, and measured. This local population of D. pittieri is spatially inhomogeneous, in that density increases with increasing wind exposure; D. pittieri are more abundant near ridge crests than lower on windward slopes. The important and ubiquitous phenomenon of spatial inhomogeneity in population density is addressed and corrected for in spatial analyses by the application of the inhomogeneous version of Ripley's K. The spatial patterns of four size classes of D. pittieri (<5 cm dbh, 5-10 cm dbh, 10-20 cm dbh, and> 20 cm dbh) were investigated. Within the large-scale trend in density driven by wind exposure, D. pittieri saplings are clumped at the scale of treefall gaps and at the scale of patches of aggregated gaps. D. pittieri 5-10 cm dbh are randomly distributed, apparently due to competitive thinning of sapling clumps during the early stages of gap-phase regeneration. D. pittieri larger than 10 cm dbh are overdispersed at a scale larger than that of patches of gaps. Natural disturbance can influence the distribution of shade intolerant tree populations at several different spatial scales, and can have discordant effects at different life history stages.

Evidence for a Cenozoic radiation of ferns in an angiosperm-dominated canopy

PubMed Central

Schuettpelz, Eric; Pryer, Kathleen M.

2009-01-01

In today's angiosperm-dominated terrestrial ecosystems, leptosporangiate ferns are truly exceptional—accounting for 80% of the ≈11,000 nonflowering vascular plant species. Recent studies have shown that this remarkable diversity is mostly the result of a major leptosporangiate radiation beginning in the Cretaceous, following the rise of angiosperms. This pattern is suggestive of an ecological opportunistic response, with the proliferation of flowering plants across the landscape resulting in the formation of many new niches—both on forest floors and within forest canopies—into which leptosporangiate ferns could diversify. At present, one-third of leptosporangiate species grow as epiphytes in the canopies of angiosperm-dominated tropical rain forests. However, we know too little about the evolutionary history of epiphytic ferns to assess whether or not their diversification was in fact linked to the establishment of these forests, as would be predicted by the ecological opportunistic response hypothesis. Here we provide new insight into leptosporangiate diversification and the evolution of epiphytism by integrating a 400-taxon molecular dataset with an expanded set of fossil age constraints. We find evidence for a burst of fern diversification in the Cenozoic, apparently driven by the evolution of epiphytism. Whether this explosive radiation was triggered simply by the establishment of modern angiosperm-dominated tropical rain forest canopies, or spurred on by some other large-scale extrinsic factor (e.g., climate change) remains to be determined. In either case, it is clear that in both the Cretaceous and Cenozoic, leptosporangiate ferns were adept at exploiting newly created niches in angiosperm-dominated ecosystems. PMID:19567832

Evidence for a Cenozoic radiation of ferns in an angiosperm-dominated canopy.

PubMed

Schuettpelz, Eric; Pryer, Kathleen M

2009-07-07

In today's angiosperm-dominated terrestrial ecosystems, leptosporangiate ferns are truly exceptional--accounting for 80% of the approximately 11,000 nonflowering vascular plant species. Recent studies have shown that this remarkable diversity is mostly the result of a major leptosporangiate radiation beginning in the Cretaceous, following the rise of angiosperms. This pattern is suggestive of an ecological opportunistic response, with the proliferation of flowering plants across the landscape resulting in the formation of many new niches--both on forest floors and within forest canopies--into which leptosporangiate ferns could diversify. At present, one-third of leptosporangiate species grow as epiphytes in the canopies of angiosperm-dominated tropical rain forests. However, we know too little about the evolutionary history of epiphytic ferns to assess whether or not their diversification was in fact linked to the establishment of these forests, as would be predicted by the ecological opportunistic response hypothesis. Here we provide new insight into leptosporangiate diversification and the evolution of epiphytism by integrating a 400-taxon molecular dataset with an expanded set of fossil age constraints. We find evidence for a burst of fern diversification in the Cenozoic, apparently driven by the evolution of epiphytism. Whether this explosive radiation was triggered simply by the establishment of modern angiosperm-dominated tropical rain forest canopies, or spurred on by some other large-scale extrinsic factor (e.g., climate change) remains to be determined. In either case, it is clear that in both the Cretaceous and Cenozoic, leptosporangiate ferns were adept at exploiting newly created niches in angiosperm-dominated ecosystems.

[Attitudes toward the environment: a North / South analysis].

PubMed

Worcester, R M; Corrado, M

1992-01-01

The results of public opinion surveys were used to assess the variation in views and attitudes toward the environment among different social strata in several countries. The developed countries have recently become concerned about the disappearance of the rain forests, but mere survival is more of a preoccupation for the majority of Brazilians than damage tot he rain forest. A survey of a representative national sample during the 1989 presidential election indicated that fewer than 10% of Brazilians considered ecological problems among the 3 major national problems. But in a survey to determine which environmental problems in Brazil were considered most serious, burning of the tropical forest was identified by the greatest proportion of respondents, 19%, followed by industrial pollution of rivers and cities, 17%. Surveys in 1990-91 in Great Britain indicated in contrast that some 92% of respondents were in favor of 1 or more measures to limit deterioration of the tropical forest, such as limiting importation of wood from countries not protecting their forests or contributing funds to ecological groups. Opinion surveys in British Columbia, whose main economic activity is forestry, showed that 40% of respondents considered ecological problems to be the most serious, ahead of unemployment, the economy, or social services. But specific questions on clear cutting of forests, preservation of old forest in Vancouver, or pollution controls for the paper industry, which closely affected the local economy, divided opinion and probably demonstrated a desire to protect the environment without too greatly disturbing the local economy. Study of the reactions of developing country populations to environmental problems is difficult because of language and cultural barriers, political instability, war, natural catastrophes, and difficulty of establishing representative samples, among other factors. Results of a study of the opinion of the Maya population of southern Mexico and northern Guatemala on deforestation, land use, and development are expected to appear shortly. A study in Lima identified the proliferation of refuse in the street as the worst ecological problem for 42%, followed by air pollution caused by automotive exhausts for 30%. Only 1% believed disappearance of the rain forest to be the principal problem. The ordering of ecological problems was significantly influenced by social class. A comparison of the views on ecological problems of opinion leaders and the general public was conducted in 1988-89 in 16 countries on 4 continents. In most cases, the opinions of the leaders corresponded to those of the general public. Most respondents in all countries except Saudi Arabia considered their environment of average quality, and a majority believed that the place where they lived had worsening environmental conditions over the past decade. Majorities in all countries except Japan stated they support organizations that protect the environment.

The Importance of Seedlings Quality in Timber and Bio-energy Production on marginal lands

NASA Astrophysics Data System (ADS)

Fragkiskakis, Nikitas; Kiourtsis, Fotios; Keramitzis, Dimitrios; Papatheodorou, Ioannis; Georgiadou, Margarita; Repmann, Frank; Gerwin, Werner

2017-04-01

One of the main issues that the forest sector is facing is to achieve a balance between the demand for biomass &wood production and the need to preserve the sustainability and biodiversity of forest ecosystems. The purposes of the new approaches are to ensure more efficient management of ecosystems and implement intensive forestry that will increase biomass production & timber yields. To achieve this, we need to determine the macroeconomic potential of the various options available, including the use of biotechnology and genetics. The success of the forests plantations capacity may be solved through forest certification, based on: a) Stabilization of the forests and soils structure. b) Hierarchy of biomass production in the forest's management process. c) Οrganization and implementation of effective plantation on marginal lands. d) Maintenance or increase of forest productivity by introducing new items as and when they are required. It is important to evaluate of the influence of factors such as the quality of soils of plantation areas, the utilization of the genetic resources and the management of forest operations with the environmental economic criteria such as net present value of benefits (NPV) and the corresponding flow annuities (EACF).The existing evaluations studies showed that the quality of the plantation areas has the most influence and through validated quality seed production can generate an increase in the NPV up to 73%. The importance of seedlings quality in timber and bio-energy production on marginal lands based on the literature it is estimated according to the heredity of the characteristics of the wood structure (except shrinkage). This clearly indicate that seedlings with the appropriate morphological characteristics can significantly improve the growth performance and help to support the development of biomass plantations oriented in tailor-made timber and bio-energy production.

Discovery of the Dinoponera lucida male (Hymenoptera, Formicidae), a threatened giant ant from the Atlantic rain forest.

PubMed

Escárraga, Mayron E; Lattke, John E; Azevedo, Celso O

2017-11-10

The male of the endangered ant Dinoponera lucida Emery is described, providing morphometric measurements, high-resolution images, and a distribution map of the species. This ant inhabits the Brazilian Atlantic forest, an ecosystem strongly impacted by fragmentation. The males show clear morphological differences from the known males of other species of Dinoponera. We briefly discuss the relevance of the male description for the conservation strategies of this ant.

Layout Guide for Burnt and Un-burnt Tropical Forest: The Diversity of Forest Plants and Insetcs for Sustainable Environmental

NASA Astrophysics Data System (ADS)

Watiniasih, N. L.; Tambunan, J.; Merdana, I. M.; Antara, I. N. G.

2018-04-01

Forest fire is a common phenomenon in tropical forest likes in Indonesia. Beside the effect of soaring heat and lack of rain during dry season due to the tropical climate, farming system is also reported as one reason of forest fire in Indonesia. People of surrounding areas and neighbouring countries are suffering from the effect of forest fire. Plants and animals are the most suffer from this occurrence that they cannot escape. This study aimed to investigate the effect of previously burnt and un-burnt tropical forest in Borneo Island on the plant and insect diversity of the tropical forest. The result of the study found that the plants in previously burnt forest area was dominated by one species, while higher and more stable plant diversity was found in un-burnt forest. Although the number of individual insects was higher in previously burnt tropical forest, but the insects was more diverse in un-burnt tropical forest. The alteration of environmental conditions in previously burnt and un-burnt forest indicate that the energy held in natural forest support higher number and more stable insects than previously burnt forest.

Tested Demonstrations.

ERIC Educational Resources Information Center

Gilbert, George L., Ed.

1987-01-01

Describes two laboratory demonstrations in chemistry. One uses dry ice, freon, and freezer bags to demonstrate volume changes, vapor-liquid equilibrium, a simulation of a rain forest, and vaporization. The other uses the clock reaction technique to illustrate fast reactions and kinetic problems in releasing carbon dioxide during respiration. (TW)

Science, Politics, and the Mass Media: On Biased Communication of Environmental Issues.

ERIC Educational Resources Information Center

Roll-Hansen, Nils

1994-01-01

Based on the study of two issues, forest death from acid rain and the size of whale stocks, this article shows how the constraints of commercial mass media can be contrary to the task of enlightenment. (42 references) (Author/MKR)

Landsat analysis of tropical forest succession employing a terrain model

NASA Technical Reports Server (NTRS)

Barringer, T. H.; Robinson, V. B.; Coiner, J. C.; Bruce, R. C.

1980-01-01

Landsat multispectral scanner (MSS) data have yielded a dual classification of rain forest and shadow in an analysis of a semi-deciduous forest on Mindonoro Island, Philippines. Both a spatial terrain model, using a fifth side polynomial trend surface analysis for quantitatively estimating the general spatial variation in the data set, and a spectral terrain model, based on the MSS data, have been set up. A discriminant analysis, using both sets of data, has suggested that shadowing effects may be due primarily to local variations in the spectral regions and can therefore be compensated for through the decomposition of the spatial variation in both elevation and MSS data.

Crepidotus rubrovinosus sp. nov. and Crepidotus septicoides, found in the cloud forest of eastern Mexico, with notes on Crepidotus fusisporus var. longicystis.

PubMed

Bandala, Victor M; Montoya, Leticia; Horak, Egon

2006-01-01

Two species of Crepidotus are recorded from cloud forest in the central region of Veracruz State (eastern Mexico): Crepidotus rubrovinosus sp. nov. and Crepidotus septicoides. The latter species was known previously only from the type locality in Brazil and from one record in tropical rain forest in southern Veracruz (as C. longicystis s. str. Singer). Descriptions, illustrations and discussions for both taxa are provided. A type study of C. fusisporus var. longicystis from USA is included, and it is concluded that the collection supporting this variety belongs to C. luteolus.

Candida queiroziae sp. nov., a cellobiose-fermenting yeast species isolated from rotting wood in Atlantic Rain Forest.

PubMed

Santos, Renata O; Cadete, Raquel M; Badotti, Fernanda; Mouro, Adriane; Wallheim, Daniela O; Gomes, Fátima C O; Stambuk, Boris U; Lachance, Marc-André; Rosa, Carlos A

2011-03-01

Eight strains of a novel yeast species were isolated from rotting wood and wood-boring insects in Atlantic Rain Forest ecosystems in Brazil. Sequences of the D1/D2 domains of the large subunit of the rRNA gene showed that the yeast belongs to the Scheffersomyces clade and that it is related to Candida lignicola and Candida coipomoensis. The new species was isolated from rotting wood of three different localities and a wood-boring insect suggesting that these substrates are its ecological niche. This new yeast species is able to assimilate cellobiose and other compounds related to rotting wood. Strong fermentation of cellobiose in Durham tubes was observed for the strains of this new yeast. The new species produced an intracellular β-glucosidase responsible for cellobiose hydrolysis. The novel species, Candida queiroziae sp. nov., is proposed to accommodate these isolates. The type strain of C. queiroziae is UFMG-CLM 5.1(T) (=CBS 11853(T) = NRRL Y-48722(T)).

Primers of glycosaminoglycan biosynthesis from Peruvian rain forest plants.

PubMed

Taylor, W H; Sinha, A; Khan, I A; McDaniel, S T; Esko, J D

1998-08-28

We have developed a rapid, high throughput screening assay for compounds that alter the assembly of glycosaminoglycan chains in Chinese hamster ovary cells. The assay uses autoradiography to measure the binding of newly synthesized [35S]proteoglycans and [35S]glycosaminoglycans to a positively charged membrane. Screening over 1000 extracts from a random plant collection obtained from the Amazon rain forest yielded five plants that stimulated glycosaminoglycan assembly in both wild-type cells and a mutant cell line defective in xylosyltransferase (the first committed enzyme involved in glycosaminoglycan biosynthesis). Fractionation of an extract of Maieta guianensis by silica gel and reverse-phase chromatography yielded two pure compounds with stimulatory activity. Spectroscopic analysis by NMR and mass spectrometry revealed that the active principles were xylosides of dimethylated ellagic acid. One of the compounds also contained a galloyl group at C-3 of the xylose moiety. These findings suggest that plants and other natural products may be a source of agents that can potentially alter glycosaminoglycan and proteoglycan formation in animal cells.

An unusual strain of Venezuelan encephalitis virus existing sympatrically with subtype I-D strains in a Peruvian rain forest.

PubMed

Scherer, W F; Chin, J

1983-07-01

In 1971, an unusual strain of Venezuelan encephalitis (VE) virus (71D1252) was recovered from the same small area of a rain forest in the western Amazon basin of South America near Iquitos, Loreto, Peru, from which strains of subtype I-D were recovered. The marker characteristics of this strain resembled most closely those of VE subtype III (Mucambo) and were distinctly different from coexisting I-D strains. Thus the concurrent presence of two different VE virus subtypes in one place was a striking exception to the usual geographic allopatry of VE virus subtypes. Strain 71D1252 also contained temperature sensitive (ts) (37 degrees C versus 39 degrees C) virions in the original mosquito suspension and first suckling mouse passage brain tissue suspensions. It thus represents one of the few so-far-reported ts strains of viruses found in nature, and the only natural ts strain of VE virus.

Combination of support vector machine, artificial neural network and random forest for improving the classification of convective and stratiform rain using spectral features of SEVIRI data

NASA Astrophysics Data System (ADS)

Lazri, Mourad; Ameur, Soltane

2018-05-01

A model combining three classifiers, namely Support vector machine, Artificial neural network and Random forest (SAR) is designed for improving the classification of convective and stratiform rain. This model (SAR model) has been trained and then tested on a datasets derived from MSG-SEVIRI (Meteosat Second Generation-Spinning Enhanced Visible and Infrared Imager). Well-classified, mid-classified and misclassified pixels are determined from the combination of three classifiers. Mid-classified and misclassified pixels that are considered unreliable pixels are reclassified by using a novel training of the developed scheme. In this novel training, only the input data corresponding to the pixels in question to are used. This whole process is repeated a second time and applied to mid-classified and misclassified pixels separately. Learning and validation of the developed scheme are realized against co-located data observed by ground radar. The developed scheme outperformed different classifiers used separately and reached 97.40% of overall accuracy of classification.

Impacts of fire on sources of soil CO2 efflux in a dry Amazon rain forest.

PubMed

Metcalfe, Daniel B; Rocha, Wanderley; Balch, Jennifer K; Brando, Paulo M; Doughty, Christopher E; Malhi, Yadvinder

2018-05-10

Fire at the dry southern margin of the Amazon rainforest could have major consequences for regional soil carbon (C) storage and ecosystem carbon dioxide (CO 2 ) emissions, but relatively little information exists about impacts of fire on soil C cycling within this sensitive ecotone. We measured CO 2 effluxes from different soil components (ground surface litter, roots, mycorrhizae, soil organic matter) at a large-scale burn experiment designed to simulate a severe but realistic potential future scenario for the region (Fire plot) in Mato Grosso, Brazil, over one year, and compared these measurements to replicated data from a nearby, unmodified Control plot. After four burns over five years, soil CO 2 efflux (R s ) was ~ 5.5 t C ha -1 yr -1 lower on the Fire plot compared to the Control. Most of the Fire plot R s reduction was specifically due to lower ground surface litter and root respiration. Mycorrhizal respiration on both plots was around ~ 20% of R s . Soil surface temperature appeared to be more important than moisture as a driver of seasonal patterns in R s at the site. Regular fire events decreased the seasonality of R s at the study site, due to apparent differences in environmental sensitivities among biotic and abiotic soil components. These findings may contribute towards improved predictions of the amount and temporal pattern of C emissions across the large areas of tropical forest facing increasing fire disturbances associated with climate change and human activities. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Study of rain attenuation in Ka band for satellite communication in South Korea

NASA Astrophysics Data System (ADS)

Shrestha, Sujan; Choi, Dong-You

2016-10-01

The important factor to be considered in the link budget estimation for satellite communication systems, operating at frequencies above 10 GHz is the rain attenuation. Scattering and absorption are the main concern for system designers at these frequency bands. This has resulted in the need for suitable prediction models that can best provide estimates of attenuation due to rain with available information of rain attenuation data. Researchers have developed models that can be used to estimate 1-min rainfall attenuation distribution for earth space link but there is still some confusion with regard to choosing the right model to predict attenuation for the location of interest. In this context, the existing prediction models need to be tested against the measured results. This paper presents studies on rain attenuation at 19.8 GHz, which specifies the performance parameters for Ka-Band under earth space communication system. It presents the experimental result of rain rates and rain-induced attenuation in 19.8 and 20.73 GHz for vertical and circular polarization respectively. The received signal data for rain attenuation and rain rate were collected at 10 s intervals over a three year periods from 2013 to 2015. The data highlights the impact of clear air variation and rain fade loss. Rain rate data was measured through OTT Parsivel. During the observation period, rain rates of about 50 mm/h and attenuation values of 11.6 dB for 0.01% of the time were noted. The experimental link was set up at Korea Radio Promotion Association, Mokdong, Seoul. Out of several models, this paper present discussion and comparison of ITU-R P.618-12, Unified Method, Dissanayake Allnutt and Haidara (DAH), Simple Attenuation (SAM), Crane Global and Ramachandran and Kumar models. The relative error margin of 27.51, 89.84,72.46% and 67.24, 130.84, 166.48% are obtained for 0.1%, 0.01% and 0.001% of the time for 19.8 and 20.73 GHz under vertical and circular polarization respectively from ITU-R P. 618-12 method which has been analyzed in the further section of this article. In order to obtain the better approximation of rain induced attenuation, the suitable method is proposed for earth space link whose efficiency have been compared with prominent rain attenuation models. The method provides useful information for system engineers and researchers in making a decision over the choice of suitable rain attenuation prediction method for earth space communication operating in the South Korea region.

Forest tree pollen dispersal via the water cycle.

PubMed

Williams, Claire G

2013-06-01

Pine pollen (Pinus spp.), along with other atmospheric particles, is dispersed by the water cycle, but this mode of dispersal requires cloud-pollen interactions that depend on taxon-specific biological properties. In the simplest form of this dispersal, pine pollen ascends vertically to altitudes of 2 to 6 km, where a fraction is captured by mixed-phase cloud formation. Captured pollen accretes into frozen droplets, which ultimately descend as rain, snow, or hail. Whether Pinus pollen can still germinate after its exposure to high-altitude freezing is pertinent to (1) how forests adapt to climate change and (2) potential gene flow between genetically modified plantation species and their conspecific relatives. • To address this question, pollen from four Old World and two New World Pinus species were subjected to immersion freezing, a common cloud formation mode, under laboratory conditions. • Some pollen grains immersed at -20°C for 15, 60, or 120 min in either a dehydrated or a water-saturated state were still capable of germination. After exposure, dehydrated pine pollen had higher germination (43.3%) than water-saturated pollen (7.6%). • Pine pollen exposed to freezing during cloud formation can still germinate, raising the question of whether rain-delivered live pollen might be linked to rain-facilitated pollination. Dispersal of live pine pollen via cloud formation and the water cycle itself deserves closer study.

Building genomic resources for Theobroma cacao

USDA-ARS?s Scientific Manuscript database

Theobroma cacao L (cacao: Malvaceae) is a small tree endemic to the Amazonian rain forest, where it most likely evolved. Cacao persists in populations of naturally outcrossing and inbreeding plants, as it is a species with a complex system of self-incompatibility, where only a fraction of the popul...

This Artroom Is a Jungle!

ERIC Educational Resources Information Center

Porter, Karen A.

1984-01-01

Turning the art room into a tropical paradise engaged students from February to May. Rather than limit themselves to traditional art activities, students studying Gauguin created a total environment, including a creature hall of fame, a rain forest, a village market place, an island paradise, and a jungle village. (IS)

Global change effects on Bromus tectorum L. (Poaceae) at its high-elevation range margin

USGS Publications Warehouse

Concilio, Amy L.; Loik, Michael E.; Belnap, Jayne

2013-01-01

Global change is likely to affect invasive species distribution, especially at range margins. In the eastern Sierra Nevada, California, USA, the invasive annual grass, Bromus tectorum, is patchily distributed and its impacts have been minimal compared with other areas of the Intermountain West. We used a series of in situ field manipulations to determine how B. tectorum might respond to changing climatic conditions and increased nitrogen deposition at the high-elevation edge of its invaded range. Over 3 years, we used snow fences to simulate changes in snowpack, irrigation to simulate increased frequency and magnitude of springtime precipitation, and added nitrogen (N) at three levels (0, 5, and 10 g m-2) to natural patches of B. tectorum growing under the two dominant shrubs, Artemisia tridentata and Purshia tridentata, and in intershrub spaces (INTR). We found that B. tectorum seedling density in April was lower following deeper snowpack possibly due to delayed emergence, yet there was no change in spikelet production or biomass accumulation at the time of harvest. Additional spring rain events increased B. tectorum biomass and spikelet production in INTR plots only. Plants were primarily limited by water in 2009, but colimited by N and water in 2011, possibly due to differences in antecedent moisture conditions at the time of treatments. The threshold at which N had an effect varied with magnitude of water additions. Frequency of rain events was more influential than magnitude in driving B. tectorum growth and fecundity responses. Our results suggest that predicted shifts from snow to rain could facilitate expansion of B. tectorum at high elevation depending on timing of rain events and level of N deposition. We found evidence for P-limitation at this site and an increase in P-availability with N additions, suggesting that stoichiometric relationships may also influence B. tectorum spread.

Temperate Pine Barrens and Tropical Rain Forests Are Both Rich in Undescribed Fungi

PubMed Central

Luo, Jing; Walsh, Emily; Naik, Abhishek; Zhuang, Wenying; Zhang, Keqin; Cai, Lei; Zhang, Ning

2014-01-01

Most of fungal biodiversity on Earth remains unknown especially in the unexplored habitats. In this study, we compared fungi associated with grass (Poaceae) roots from two ecosystems: the temperate pine barrens in New Jersey, USA and tropical rain forests in Yunnan, China, using the same sampling, isolation and species identification methods. A total of 426 fungal isolates were obtained from 1600 root segments from 80 grass samples. Based on the internal transcribed spacer (ITS) sequences and morphological characteristics, a total of 85 fungal species (OTUs) belonging in 45 genera, 23 families, 16 orders, and 6 classes were identified, among which the pine barrens had 38 and Yunnan had 56 species, with only 9 species in common. The finding that grass roots in the tropical forests harbor higher fungal species diversity supports that tropical forests are fungal biodiversity hotspots. Sordariomycetes was dominant in both places but more Leotiomycetes were found in the pine barrens than Yunnan, which may play a role in the acidic and oligotrophic pine barrens ecosystem. Equal number of undescribed fungal species were discovered from the two sampled ecosystems, although the tropical Yunnan had more known fungal species. Pine barrens is a unique, unexplored ecosystem. Our finding suggests that sampling plants in such unexplored habitats will uncover novel fungi and that grass roots in pine barrens are one of the major reservoirs of novel fungi with about 47% being undescribed species. PMID:25072783

Space communication link propagation data for selected cities within the multiple beam and steerable antenna coverage areas of the advanced communications technology satellite

NASA Technical Reports Server (NTRS)

Manning, Robert M.

1988-01-01

Rain attenuation propagation data for 68 cities within the coverage area of the multiple beam and steerable antennas of the Advanced Communications Technology Satellite (ACTS) are presented. These data provide the necessary data base for purposes of communication link power budgeting and rain attenuation mitigation controller design. These propagation parameters are derived by applying the ACTS Rain Attenuation Prediction Model to these 68 locations. The propagation parameters enumerated in tabular form for each location are as follows: (1) physical description of the link and location (e.g., latitude, longitude, antenna elevation angle, etc.), link availability versus attenuation margin (also in graphical form), fading time across fade depths of 3, 5, 8, and 15 dB versus fade duration, and required fade control response time for controller availabilities of 99.999, 99.99, 99.9, and 99 percent versus sub-threshold attenuation levels. The data for these specific locations can be taken to be representative of regions near these locations.

Annual monsoon rains recorded by Jurassic dunes.

PubMed

Loope, D B; Rowe, C M; Joeckel, R M

2001-07-05

Pangaea, the largest landmass in the Earth's history, was nearly bisected by the Equator during the late Palaeozoic and early Mesozoic eras. Modelling experiments and stratigraphic studies have suggested that the supercontinent generated a monsoonal atmospheric circulation that led to extreme seasonality, but direct evidence for annual rainfall periodicity has been lacking. In the Mesozoic era, about 190 million years ago, thick deposits of wind-blown sand accumulated in dunes of a vast, low-latitude desert at Pangaea's western margin. These deposits are now situated in the southwestern USA. Here we analyse slump masses in the annual depositional cycles within these deposits, which have been described for some outcrops of the Navajo Sandstone. Twenty-four slumps, which were generated by heavy rainfall, appear within one interval representing 36 years of dune migration. We interpret the positions of 20 of these masses to indicate slumping during summer monsoon rains, with the other four having been the result of winter storms. The slumped lee faces of these Jurassic dunes therefore represent a prehistoric record of yearly rain events.

Tourism climatology for camping: a case study of two Ontario parks (Canada)

NASA Astrophysics Data System (ADS)

Hewer, Micah J.; Scott, Daniel; Gough, William A.

2015-08-01

Climate and weather act as central motivators for the travel decisions of tourists. Due to their seasonality, these factors determine the availability and quality of certain outdoor recreational activities. Park visitation in Ontario, Canada, has been identified as a weather sensitive tourism and recreation activity. This study used a survey-based approach to identify and compare stated weather preferences and thresholds, as well as weather-related decision-making for campers at two provincial parks in Ontario, Canada. The two parks were selected for differing physical and environmental characteristics (forested lake versus coastal beach). Statistically significant differences were detected between the two parks in relation to the importance of weather and weather-based decision-making. Specific temperatures that were considered ideal and thresholds that were too cool and too warm were identified for both parks, both during the day and the night. Heavy rain and strong winds were the most influential factors in weather-related decision-making and on-site behavioural adaptations. Beach campers placed greater importance on the absence of rain and the presence of comfortable temperatures compared to forest campers. In addition, beach campers were more likely to leave the park early due to incremental weather changes. The results of this study suggest that beach campers are more sensitive to weather than forest campers.

Estimation of tropical forest canopy temperatures, thermal response numbers, and evapotranspiration using an aircraft-based thermal sensor

NASA Technical Reports Server (NTRS)

Luvall, Jeffrey C.; Lieberman, Diana; Lieberman, Milton; Hartshorn, Gary S.; Peralta, Rodolfo

1990-01-01

Thermal infrared Multispectral Scanner (TIMS) data were collected at a resolution of 5 to 10 m from a tropical rain forest over an elevation gradient from 35 to 2700 m in the Braulio Carrillo National Park in Costa Rica. Flight lines were repeated with a 15 to 30 minute time difference for measurement of forest canopy thermal response over time. Concurrent radiosonde measurements of atmospheric profiles of air temperature and moisture provided inputs to LOWTRAN6 for atmospheric radiance corrections of the TIMS data. Techniques for using calibrated aircraft-based thermal scanner data to examine tropical forest canopy thermal properties are described. Forest canopy temperature changes over time assessed between repeated, duplicated flight lines were combined with estimates of surface radiative energy measurements from towers above the forest canopy to determine temperature spatial variability, calculate Thermal Response Numbers (TRN), and estimate evapotranspiration along the elevation gradient from selected one hectare forest inventory plots.

Acid Rain

USGS Publications Warehouse

Bricker, Owen P.; Rice, Karen C.

1995-01-01

Although acid rain is fading as a political issue in the United States and funds for research in this area have largely disappeared, the acidity of rain in the Eastern United States has not changed significantly over the last decade, and it continues to be a serious environmental problem. Acid deposition (commonly called acid rain) is a term applied to all forms of atmospheric deposition of acidic substances - rain, snow, fog, acidic dry particulates, aerosols, and acid-forming gases. Water in the atmosphere reacts with certain atmospheric gases to become acidic. For example, water reacts with carbon dioxide in the atmosphere to produce a solution with a pH of about 5.6. Gases that produce acids in the presence of water in the atmosphere include carbon dioxide (which converts to carbonic acid), oxides of sulfur and nitrogen (which convert to sulfuric and nitric acids}, and hydrogen chloride (which converts to hydrochloric acid). These acid-producing gases are released to the atmosphere through natural processes, such as volcanic emissions, lightning, forest fires, and decay of organic matter. Accordingly, precipitation is slightly acidic, with a pH of 5.0 to 5.7 even in undeveloped areas. In industrialized areas, most of the acid-producing gases are released to the atmosphere from burning fossil fuels. Major emitters of acid-producing gases include power plants, industrial operations, and motor vehicles. Acid-producing gases can be transported through the atmosphere for hundreds of miles before being converted to acids and deposited as acid rain. Because acids tend to build up in the atmosphere between storms, the most acidic rain falls at the beginning of a storm, and as the rain continues, the acids "wash out" of the atmosphere.

Lemur traits and Madagascar ecology: coping with an island environment.

PubMed

Wright, P C

1999-01-01

The last decade's lemur research includes successes in discovering new living and extinct species and learning about the distribution, biogeography, physiology, behavior, and ecology of previously little-studied species. In addition, in both the dry forest and rain forest, long-term studies of lemur demography, life history, and reproduction, have been completed in conjunction with data on tree productivity, phenology, and climate. Lemurs contrast with anthropoids in several behavioral features, including female dominance, targeted female-female aggression, lack of sexual dimorphism regardless of mating system, sperm competition coupled with male-male aggression, high infant mortality, cathemerality, and strict seasonal breeding. Hypotheses to explain these traits include the "energy conservation hypothesis" (ECH) suggesting that harsh and unpredictable climate factors on the island of Madagascar have affected the evolution of female dominance, and the "evolutionary disequilibrium hypotheses" (EVDH) suggesting that the recent megafauna extinctions have influenced lemurs to become diurnal. These hypotheses are compared and contrasted in light of recent empirical data on climate, subfossils, and lemur behavior. New data on life histories of the rain forest lemurs at Ranomafana National Park give further support to the ECH. Birth seasons are synchronized within each species, but there is a 6-month distribution of births among species. Gestation and lactation lengths vary among sympatric lemurs, but all lemur species in the rain forest wean in synchrony at the season most likely to have abundant resources. Across-species weaning synchrony seen in Ranomafana corroborates data from the dry forest that late lactation and weaning is the life history event that is the primary focus of the annual schedule. Lemur adaptations may assure maximum offspring survival in this environment with an unpredictable food supply and heavy predation. In conclusion, a more comprehensive energy frugality hypothesis (EFH) is proposed, which postulates that the majority of lemur traits are either adaptations to conserve energy (e.g., low basal metabolic rate (BMR), torpor, sperm competition, small group size, seasonal breeding) or to maximize use of scarce resources (e.g., cathemerality, territoriality, female dominance, fibrous diet, weaning synchrony). Among primates, the isolated adaptive radiation of lemurs on Madagascar may have been uniquely characterized by selection toward efficiency to cope with the harsh and unpredictable island environment.

Spaceborne Applications of P Band Imaging Radars for Measuring Forest Biomass

NASA Technical Reports Server (NTRS)

Rignot, Eric J.; Zimmermann, Reiner; vanZyl, Jakob J.

1995-01-01

In three sites of boreal and temperate forests, P band HH, HV, and VV polarization data combined estimate total aboveground dry woody biomass within 12 to 27% of the values derived from allometric equations, depending on forest complexity. Biomass estimates derived from HV-polarization data only are 2 to 14% less accurate. When the radar operates at circular polarization, the errors exceed 100% over flooded forests, wet or damaged trees and sparse open tall forests because double-bounce reflections of the radar signals yield radar signatures similar to that of tall and massive forests. Circular polarizations, which minimize the effect of Faraday rotation in spaceborne applications, are therefore of limited use for measuring forest biomass. In the tropical rain forest of Manu, in Peru, where forest biomass ranges from 4 kg/sq m in young forest succession up to 50 kg/sq m in old, undisturbed floodplain stands, the P band horizontal and vertical polarization data combined separate biomass classes in good agreement with forest inventory estimates. The worldwide need for large scale, updated, biomass estimates, achieved with a uniformly applied method, justifies a more in-depth exploration of multi-polarization long wavelength imaging radar applications for tropical forests inventories.

ATLANTIC RAIN FOREST AND CAATINGA VEGETATION DYNAMICS EXPLAIN PHYLOGEOGRAPHICAL PATTERN OF AN ENDEMIC BRAZILIAN PALM

USDA-ARS?s Scientific Manuscript database

Technical Abstract Occurrence of a wetter and cooler climate associated with humid vegetation had been inferred for the Caatinga region during the late Pleistocene and early Holocene. The existence of rainforest migration routes in northeastern Brazil is widely recognized. Present-day rainforest nat...

Cacau Cabruca Agroforestry System of Production in Bahia, Brazil

USDA-ARS?s Scientific Manuscript database

The Cacao Cabruca Agroforestry system of production was developed by farmers in Southern Bahia probably in the beginning of the 19th century. To establish such system, farmers in the Atlantic rain forest region selectively maintained around 75 adult individual native trees per hectare, removed the o...

The Portrayal of the Environment and Development in Two Commercial Movies.

ERIC Educational Resources Information Center

Murphy, Tony P.

1993-01-01

Examined the portrayals of environment and development in two commercial movies: "Ferngully, The Last Rain Forest" and "Medicine Man." The two movies differed in their portrayal of the issues, presumably because of their targeted audiences. Suggests that further research is necessary. (Contains 26 references.) (Author/MDH)

Brunei: Abode of Peace.

ERIC Educational Resources Information Center

Schelander, Bjorn

This book introduces students to the people and the geography of Brunei. The country is filled with a variety of complex ecosystems and tropical rain forests. This book provides background information and suggested topics for an intensive study of the country. The three chapters are entitled: (1) "Introduction to Brunei"; (2) "Early…

Culex (Thaiomyia) Dispectus, A New Subgenus and Species from Thailand (Diptera: Culicidae)

DTIC Science & Technology

1966-06-01

Province; and Doi Sutep, Chiang Mai Province. Biology. Larvae have been collected on four occasions from open bamboo internodes or bamboo stumps in a...primary rain forest en- vironment. The collection from Chiang Mai was from an artificial container. Collections from Tak Province were made at an

Soil classification and carbon storage in cacao agroforestry farming systems of Bahia, Brazil

USDA-ARS?s Scientific Manuscript database

Information concerning the classification of soils and their properties under cacao agroforestry systems of the Atlantic rain forest biome region in the Southeast of Bahia Brazil is largely unknown. Soil and climatic conditions in this region are favorable for high soil carbon storage. This study is...

Ownership of Traditional Information: Moral and Legal Obligations to Compensate for Taking.

ERIC Educational Resources Information Center

McNeil, Richard J.; McNeil, Michael J.

1989-01-01

Argues that "indigenous" people transferring cultural information to other, more "developed" people should have legal protection from unfair transactions. Presents ethical and legal bases for such protection. Examples involve the knowledge of rain-forest tribes that has been used to produce valuable pharmaceutical products from…

Tropical Rain Forest Structure, Tree Growth and Dynamics along a 2700-m Elevational Transect in Costa Rica

PubMed Central

Clark, David B.; Hurtado, Johanna; Saatchi, Sassan S.

2015-01-01

Rapid biological changes are expected to occur on tropical elevational gradients as species migrate upslope or go extinct in the face of global warming. We established a series of 9 1-ha plots in old-growth tropical rainforest in Costa Rica along a 2700 m relief elevational gradient to carry out long-term monitoring of tropical rain forest structure, dynamics and tree growth. Within each plot we mapped, identified, and annually measured diameter for all woody individuals with stem diameters >10 cm for periods of 3-10 years. Wood species diversity peaked at 400-600 m and decreased substantially at higher elevations. Basal area and stem number varied by less than two-fold, with the exception of the 2800 m cloud forest summit, where basal area and stem number were approximately double that of lower sites. Canopy gaps extending to the forest floor accounted for <3% of microsites at all elevations. Height of highest crowns and the coefficient of variation of crown height both decreased with increasing elevation. Rates of turnover of individuals and of stand basal area decreased with elevation, but rates of diameter growth and stand basal area showed no simple relation to elevation. We discuss issues encountered in the design and implementation of this network of plots, including biased sampling, missing key meteorological and biomass data, and strategies for improving species-level research. Taking full advantage of the major research potential of tropical forest elevational transects will require sustaining and extending ground based studies, incorporation of new remotely-sensed data and data-acquisition platforms, and new funding models to support decadal research on these rapidly-changing systems. PMID:25856163

Inventory of forest resources (including water) by multi-level sampling. [nine northern Virginia coastal plain counties

NASA Technical Reports Server (NTRS)

Aldrich, R. C.; Dana, R. W.; Roberts, E. H. (Principal Investigator)

1977-01-01

The author has identified the following significant results. A stratified random sample using LANDSAT band 5 and 7 panchromatic prints resulted in estimates of water in counties with sampling errors less than + or - 9% (67% probability level). A forest inventory using a four band LANDSAT color composite resulted in estimates of forest area by counties that were within + or - 6.7% and + or - 3.7% respectively (67% probability level). Estimates of forest area for counties by computer assisted techniques were within + or - 21% of operational forest survey figures and for all counties the difference was only one percent. Correlations of airborne terrain reflectance measurements with LANDSAT radiance verified a linear atmospheric model with an additive (path radiance) term and multiplicative (transmittance) term. Coefficients of determination for 28 of the 32 modeling attempts, not adverseley affected by rain shower occurring between the times of LANDSAT passage and aircraft overflights, exceeded 0.83.

Tropical rain forest conservation and the twin challenges of diversity and rarity

PubMed Central

Hubbell, Stephen P

2013-01-01

Data from a global network of large, permanent plots in lowland tropical forests demonstrate (1) that the phenomenon of tropical tree rarity is real and (2) that almost all the species diversity in such forests is due to rare species. Theoretical and empirically based reasoning suggests that many of these rare species are not as geographically widespread as previously thought. These findings suggest that successful strategies for conserving global tree diversity in lowland tropical forests must pay much more attention to the biogeography of rarity, as well as to the impact of climate change on the distribution and abundance of rare species. Because the biogeography of many tropical tree species is poorly known, a high priority should be given to documenting the distribution and abundance of rare tropical tree species, particularly in Amazonia, the largest remaining tropical forested region in the world. PMID:24223266

A ground-water reconnaissance in the Pine Forest region, Haiti

USGS Publications Warehouse

Taylor, George C.; Lemoine, Rémy C.

1949-01-01

The Pine Forest region is located in southeastern Haiti. The SHADA Forest Division headquarters near the eastern end of the region is about 98 kilometers by road from Port-au-Prince. In early February 1949 the writers made a brief geologic study of the region to determine the feasibility of drilling wells to obtain water for domestic, stock and small-scale industrial use. Existing water supplies are very scanty and undependable. There are no wells in the region, and springs are notably scarce and widely separated. Water supplies are now obtained principally from rain-water catchments or from roof-tops. These supplies frequently fail during prolonged dry periods and water must be hauled from great distances.

Sequential Monte Carlo tracking of the marginal artery by multiple cue fusion and random forest regression.

PubMed

Cherry, Kevin M; Peplinski, Brandon; Kim, Lauren; Wang, Shijun; Lu, Le; Zhang, Weidong; Liu, Jianfei; Wei, Zhuoshi; Summers, Ronald M

2015-01-01

Given the potential importance of marginal artery localization in automated registration in computed tomography colonography (CTC), we have devised a semi-automated method of marginal vessel detection employing sequential Monte Carlo tracking (also known as particle filtering tracking) by multiple cue fusion based on intensity, vesselness, organ detection, and minimum spanning tree information for poorly enhanced vessel segments. We then employed a random forest algorithm for intelligent cue fusion and decision making which achieved high sensitivity and robustness. After applying a vessel pruning procedure to the tracking results, we achieved statistically significantly improved precision compared to a baseline Hessian detection method (2.7% versus 75.2%, p<0.001). This method also showed statistically significantly improved recall rate compared to a 2-cue baseline method using fewer vessel cues (30.7% versus 67.7%, p<0.001). These results demonstrate that marginal artery localization on CTC is feasible by combining a discriminative classifier (i.e., random forest) with a sequential Monte Carlo tracking mechanism. In so doing, we present the effective application of an anatomical probability map to vessel pruning as well as a supplementary spatial coordinate system for colonic segmentation and registration when this task has been confounded by colon lumen collapse. Published by Elsevier B.V.

Soil erosion and management activities on forested slopes

Treesearch

Robert R. Ziemer

1986-01-01

Some of the most productive forests in the Western United States grow on marginally stable mountainous slopes, where disturbance increases the likelihood of erosion. Much of the public's concern about, and, consequently, most of the research on, erosion from these forested areas is related more to the degradation of stream resources by eroded material than to the...

Social preferences toward energy generation with woody biomass from public forests in Montana, USA

Treesearch

Robert M. Campbell; Tyron J. Venn; Nathaniel M. Anderson

2016-01-01

In Montana, USA, there are substantial opportunities for mechanized thinning treatments on public forests to reduce the likelihood of severe and damaging wildfires and improve forest health. These treatments produce residues that can be used to generate renewable energy and displace fossil fuels. The choice modeling method is employed to examine the marginal...

Photo-based estimators for the Nevada photo-based inventory

Treesearch

Paul L. Patterson

2012-01-01

The U.S. Department of Agriculture, Forest Service, Forest Inventory and Analysis Program conducted the Nevada Photo-Based Inventory Pilot in an effort to improve precision in estimates of forest parameters, reduce field data collection costs on margin lands that are covered by slow growing woodland species, and address the potential of strategic-level inventory on...

Forest edge disturbance increases rattan abundance in tropical rain forest fragments.

PubMed

Campbell, Mason J; Edwards, Will; Magrach, Ainhoa; Laurance, Susan G; Alamgir, Mohammed; Porolak, Gabriel; Laurance, William F

2017-07-20

Human-induced forest fragmentation poses one of the largest threats to global diversity yet its impact on rattans (climbing palms) has remained virtually unexplored. Rattan is arguably the world's most valuable non-timber forest product though current levels of harvesting and land-use change place wild populations at risk. To assess rattan response to fragmentation exclusive of harvesting impacts we examined rattan abundance, demography and ecology within the forests of northeastern, Australia. We assessed the community abundance of rattans, and component adult (>3 m) and juvenile (≤3 m) abundance in five intact forests and five fragments (23-58 ha) to determine their response to a range of environmental and ecological parameters. Fragmented forests supported higher abundances of rattans than intact forests. Fragment size and edge degradation significantly increased adult rattan abundance, with more in smaller fragments and near edges. Our findings suggest that rattan increase within fragments is due to canopy disturbance of forest edges resulting in preferential, high-light habitat. However, adult and juvenile rattans may respond inconsistently to fragmentation. In managed forest fragments, a rattan abundance increase may provide economic benefits through sustainable harvesting practices. However, rattan increases in protected area forest fragments could negatively impact conservation outcomes.

Co-benefits of sustainable forest management in biodiversity conservation and carbon sequestration.

PubMed

Imai, Nobuo; Samejima, Hiromitsu; Langner, Andreas; Ong, Robert C; Kita, Satoshi; Titin, Jupiri; Chung, Arthur Y C; Lagan, Peter; Lee, Ying Fah; Kitayama, Kanehiro

2009-12-11

Sustainable forest management (SFM), which has been recently introduced to tropical natural production forests, is beneficial in maintaining timber resources, but information about the co-benefits for biodiversity conservation and carbon sequestration is currently lacking. We estimated the diversity of medium to large-bodied forest-dwelling vertebrates using a heat-sensor camera trapping system and the amount of above-ground, fine-roots, and soil organic carbon by a combination of ground surveys and aerial-imagery interpretations. This research was undertaken both in SFM applied as well as conventionally logged production forests in Sabah, Malaysian Borneo. Our carbon estimation revealed that the application of SFM resulted in a net gain of 54 Mg C ha(-1) on a landscape scale. Overall vertebrate diversity was greater in the SFM applied forest than in the conventionally logged forest. Specifically, several vertebrate species (6 out of recorded 36 species) showed higher frequency in the SFM applied forest than in the conventionally logged forest. The application of SFM to degraded natural production forests could result in greater diversity and abundance of vertebrate species as well as increasing carbon storage in the tropical rain forest ecosystems.

Co-Benefits of Sustainable Forest Management in Biodiversity Conservation and Carbon Sequestration

PubMed Central

Imai, Nobuo; Samejima, Hiromitsu; Langner, Andreas; Ong, Robert C.; Kita, Satoshi; Titin, Jupiri; Chung, Arthur Y. C.; Lagan, Peter; Lee, Ying Fah; Kitayama, Kanehiro

2009-01-01

Background Sustainable forest management (SFM), which has been recently introduced to tropical natural production forests, is beneficial in maintaining timber resources, but information about the co-benefits for biodiversity conservation and carbon sequestration is currently lacking. Methodology/Principal Findings We estimated the diversity of medium to large-bodied forest-dwelling vertebrates using a heat-sensor camera trapping system and the amount of above-ground, fine-roots, and soil organic carbon by a combination of ground surveys and aerial-imagery interpretations. This research was undertaken both in SFM applied as well as conventionally logged production forests in Sabah, Malaysian Borneo. Our carbon estimation revealed that the application of SFM resulted in a net gain of 54 Mg C ha-1 on a landscape scale. Overall vertebrate diversity was greater in the SFM applied forest than in the conventionally logged forest. Specifically, several vertebrate species (6 out of recorded 36 species) showed higher frequency in the SFM applied forest than in the conventionally logged forest. Conclusions/Significance The application of SFM to degraded natural production forests could result in greater diversity and abundance of vertebrate species as well as increasing carbon storage in the tropical rain forest ecosystems. PMID:20011516

A model for predicting propagation-related DSCS (Defense Communications Engineering Center) margin requirements

NASA Astrophysics Data System (ADS)

Shultheis, C. F.

1985-02-01

This technical report describes an analysis of the performance allocations for a satellite link, focusing specifically on a single-hop 7 to 8 GHz link of the Defense Satellite Communications System (DSCS). The analysis is performed for three primary reasons: (1) to reevaluate link power margin requirements for DSCS links based on digital signalling; (2) to analyze the implications of satellite availability and error rate allocations contained in proposed MIL-STD-188-323, system design and engineering standards for long haul digital transmission system performance; and (3) to standardize a methodology for determination of rain-related propagation constraints. The aforementioned methodology is then used to calculate the link margin requirements of typical DSCS binary/quaternary phase shift keying (BPSK/QPSK) links at 7 to 8 GHz for several different Earth terminal locations.

Environmental Impact Study of the Northern Section of the Upper Mississippi River. Pool 9.

DTIC Science & Technology

1973-11-01

Poison Ivy are the most common shrub layer vegetation, although neither is abundant in the forest proper. Vine form Poison Ivy, Virginia Creeper...Parthenocissus sp.), Wild Grape (Vitis sp.) and Smilax sp. are the common woody vines . The high unshaded edges of running sloughs in the forest areas...the forest edge, or be succeeded by 1a shrub willow zone, which ends abruptly at the forest edge. The forest 4margin is most often dominated by red or

Coral forests diversity in the outer shelf of the south Sardinian continental margin

NASA Astrophysics Data System (ADS)

Cau, Alessandro; Moccia, Davide; Follesa, Maria Cristina; Alvito, Andrea; Canese, Simonepietro; Angiolillo, Michela; Cuccu, Danila; Bo, Marzia; Cannas, Rita

2017-04-01

Ecological theory predicts that heterogeneous habitats allow more species to co-exist in a given area, but to date, knowledge on relationships between habitat heterogeneity and biodiversity of coral forests in the outer shelf and upper slope along continental margins is rather limited. We investigated biodiversity of coral forests from 8 sites spread over two different geomorphological settings (namely, pinnacles vs. canyons) in the outer shelf along Sardinian continental margin. Using a combination of multivariate statistical analyses, we show here that differences in the composition of coral assemblages among contrasting geomorphological settings were not statistically significant, whereas significant differences emerged among sites within similar geomorphologies (i.e. among pinnacles and among canyons). Our results reveal that environmental and bathymetric factors such as sediment coverage, slope of the substrate, terrain ruggedness, bathymetric positioning index and aspect were important drivers of the observed patterns of coral biodiversity, in both settings. Spatial variability of coral forests' biodiversity is affected by environmental factors that act at the scale of each geomorphological setting (i.e. within each pinnacle and canyon) rather than by the contrasting geomorphological settings themselves. This result allows us to suggest that simple categorization of benthic communities according topographically defined habitat is unlikely to be sufficient for addressing conservation purposes.

Tracing the Sources of Atmospheric Phosphorus Deposition to a Tropical Rain Forest in Panama Using Stable Oxygen Isotopes.

PubMed

Gross, A; Turner, B L; Goren, T; Berry, A; Angert, A

2016-02-02

Atmospheric dust deposition can be a significant source of phosphorus (P) in some tropical forests, so information on the origins and solubility of atmospheric P is needed to understand and predict patterns of forest productivity under future climate scenarios. We characterized atmospheric dust P across a seasonal cycle in a tropical lowland rain forest on Barro Colorado Nature Monument (BCNM), Republic of Panama. We traced P sources by combining remote sensing imagery with the first measurements of stable oxygen isotopes in soluble inorganic phosphate (δ(18)OP) in dust. In addition, we measured soluble inorganic and organic P concentrations in fine (<1 μm) and coarse (>1 μm) aerosol fractions and used this data to estimate the contribution of P inputs from dust deposition to the forest P budget. Aerosol dry mass was greater in the dry season (December to April, 5.6-15.7 μg m(-3)) than the wet season (May to November, 3.1-7.1 μg m(-3)). In contrast, soluble P concentrations in the aerosols were lower in the dry season (980-1880 μg P g(-1)) than the wet season (1170-3380 μg P g(-1)). The δ(18)OP of dry-season aerosols resembled that of nearby forest soils (∼19.5‰), suggesting a local origin. In the wet season, when the Trans-Atlantic Saharan dust belt moves north close to Panama, the δ(18)OP of aerosols was considerably lower (∼15.5‰), suggesting a significant contribution of long-distance dust P transport. Using satellite retrieved aerosol optical depth (AOD) and the P concentrations in aerosols we sampled in periods when Saharan dust was evident we estimate that the monthly P input from long distance dust transport during the period with highest Saharan dust deposition is 88 ± 31 g P ha(-1) month(-1), equivalent to between 10 and 29% of the P in monthly litter fall in nearby forests. These findings have important implications for our understanding of modern nutrient budgets and the productivity of tropical forests in the region under future climate scenarios.

Annotated list of the flora of the Bisley Area, luquillo experimental forest, Puerto Rico 1987 to 1992. Forest Service general technical report

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

Chinea, J.D.; Beymer, R.J.; Sastre de Jesus, I.

1993-08-01

The plant species of the Bisley area were surveyed for several years, mostly as a result of studies conducted under the Long-Term Ecological Research Program of the National Science Foundation. A list was prepared that contains a total of 336 plant species in 255 genera and 102 families of bryophytes and vascular plants. Within these species there are 107 tree species, 20 shrub species, 28 dicotyledonous vines, 86 herbs, 52 bryophytes, and 43 ferns. There are 22 introduced and 314 native species (of the later, 30 are endemic to Puerto Rico). Nine families account for 39 percent of all speciesmore » found in the Bisley area. Forests of the Bisley area have been classified as subtropical wet forests, lower montane rain forests, and single-dominant forests. The Bisley watersheds are covered by a secondary forest of the tabonuco type (Dacryodes excelsa). This forest type is part of the Dacryodes-Sloanea association of Puerto Rico, Hispaniola, and higher elevation islands of the Lesser Antilles.« less

Development history and bibliography of the US Forest Service crown-condition indicator for forest health monitoring.

PubMed

Randolph, KaDonna C

2013-06-01

Comprehensive assessment of individual-tree crown condition by the US Department of Agriculture, Forest Service, Forest Inventory and Analysis (FIA) Program has its origins in the concerns about widespread forest decline in Europe and North America that developed in the late 1970s and early 1980s. Programs such as the US National Acid Precipitation Assessment Program, US National Vegetation Survey, Canadian Acid Rain National Early Warning System, and joint US-Canadian North American Sugar Maple Decline Project laid the groundwork for the development of the US Forest Service crown-condition indicator. The crown-condition assessment protocols were selected and refined through literature review, peer review, and field studies in several different forest types during the late 1980s and early 1990s. Between 1980 and 2011, 126 publications relating specifically to the crown-condition indicator were added to the literature. The majority of the articles were published by the US Department of Agriculture, Forest Service or other State or Federal government agency, and more than half were published after 2004.

Chemical characterization of fog and rain water collected at the eastern Andes cordillera

NASA Astrophysics Data System (ADS)

Beiderwieden, E.; Wrzesinsky, T.; Klemm, O.

2005-06-01

During a three month period in 2003 and 2004, the chemistry of fog and rainwater were studied at the "El Tiro" site in a tropical mountain forest ecosystem in Ecuador, South America. The fogwater samples were collected using a passive fog collector, and for the rain water, a standard rain sampler was employed. For all samples, electric conductivity, pH, and the concentrations of NH4+, K+, Na+, Ca2+, Mg2+, Cl-, NO3-, PO43-, and SO42-, were measured. For each fog sample, a 5 day back trajectory was calculated by the use of the HYSPLIT model. Two types of trajectories occurred. One type was characterized by advection of air masses from the East over the Amazonian basin, the other trajectory arrived one from the West after significant travel time over the Pacific Ocean. We found considerably higher ion concentrations in fogwater samples than in rain samples. Median pH values are 4.58 for fog water, and 5.26 for the rain samples, respectively. The median electric conductivity was 23 µS cm-1 for the fog and 6 µS cm-1 for the rain. The concentrations of all analysed ions were relatively low compared to other mountainous sites (Weathers et al., 1988; Elias et al., 1995; Schemenauer et al., 1995; Wrzesinsky and Klemm, 2000; Zimmermann and Zimmermann, 2002). The continent samples exhibit higher concentrations of most ions as compared to the pacific samples.

Comparative effects of sulfuric and nitric acid rain on litter decomposition and soil microbial community in subtropical plantation of Yangtze River Delta region.

PubMed

Liu, Xin; Zhang, Bo; Zhao, Wenrui; Wang, Ling; Xie, Dejin; Huo, Wentong; Wu, Yanwen; Zhang, Jinchi

2017-12-01

Acid rain is mainly caused by dissolution of sulfur dioxide and nitrogen oxides in the atmosphere, and has a significant negative effect on ecosystems. The relative composition of acid rain is changing gradually from sulfuric acid rain (SAR) to nitric acid rain (NAR) with the rapidly growing amount of nitrogen deposition. In this study, we investigated the impact of simulated SAR and NAR on litter decomposition and the soil microbial community over four seasons since March 2015. Results first showed that the effects of acid rain on litter decomposition and soil microbial were positive in the early period of the experiment, except for SAR on soil microbes. Second, soil pH with NAR decreased more rapidly with the amount of acid rain increased in summer than with SAR treatments. Only strongly acid rain (both SAR and NAR) was capable of depressing litter decomposition and its inhibitory effect was stronger on leaf than on fine root litter. Meanwhile, NAR had a higher inhibitory effect on litter decomposition than SAR. Third, in summer, autumn and winter, PLFAs were negatively impacted by the increased acidity level resulting from both SAR and NAR. However, higher acidity level of NAR (pH=2.5) had the strongest inhibitory impact on soil microbial activity, especially in summer. In addition, Gram-negative bacteria (cy19:0) and fungi (18:1ω9) were more sensitive to both SAR and NAR, and actinomycetes was more sensitive to SAR intensity. Finally, soil total carbon, total nitrogen and pH were the most important soil property factors affecting soil microbial activity, and high microbial indices (fungi/bacteria) with high soil pH. Our results suggest that the ratio of SO 4 2- to NO 3 - in acid rain is an important factor which could affect litter decomposition and soil microbial in subtropical forest of China. Copyright © 2017. Published by Elsevier B.V.

Biogeochemical effects of forest vegetation on acid precipitation-related water chemistry: a case study in southwest China.

PubMed

Chen, Jing; Li, Wei; Gao, Fang

2010-10-06

The elemental composition of rainwater, throughfall, and soil solutions of a forest ecosystem in the acid rain control region of southwest China was investigated during 2007-2008 to assess the acid buffering capacity of different forest covers. A possible seasonal distribution of wet deposition was identified. Sulfur was determined as the dominant acidification precursor in this region. The chemical composition of rainfall intercepted by the forest canopy was modified substantially; generally the ion concentrations were increased by dry deposition and foliar leaching. As an exception, the concentration of NH(4)(+) and NO(3)(-) decreased in throughfall, which was probably due to the absorption of nitrogen by the leaves. Elemental concentrations in soil solutions decreased with depth. The water conservation capacity of different forests was also evaluated. The most appropriate forest vegetation for water conservation and remediation of acid precipitation in this region was explored for the sake of ecosystem management, ecological restoration and economic development.

The influence of habitat structure on bird species composition in lowland malaysian rain forests.

PubMed

Mansor, Mohammad Saiful; Sah, Shahrul Anuar Mohd

2012-05-01

Bird surveys were conducted in the Bukit Kepala Gajah limestone area in Lenggong, Perak from July 2010 to January 2011. The study area was divided into three zones: forest edge, forest intermediate and forest interior. A point-count distance sampling method was used in the bird surveys. The study recorded 7789 detections, representing 100 bird species belonging to 28 families. Pycnonotidae, Timaliidae and Nectariniidae were the dominant families overall and showed the highest number of observations recorded in the study area whereas Motacillidae showed the fewest observations. The bird species were grouped into three feeding guilds: insectivores, frugivores and others (omnivores, carnivores, nectarivores and granivores). The species richness of insectivorous birds differed significantly among the forest zones sampled (Kruskal-Wallis: α=0.05, H=10.979, d.f.=2, p=0.004), with more insectivorous birds occurring in the forest interior. No significant differences were found among the zones in the species richness of either the frugivore guild or the composite others guild.

The Influence of Habitat Structure on Bird Species Composition in Lowland Malaysian Rain Forests

PubMed Central

Mansor, Mohammad Saiful; Sah, Shahrul Anuar Mohd

2012-01-01

Bird surveys were conducted in the Bukit Kepala Gajah limestone area in Lenggong, Perak from July 2010 to January 2011. The study area was divided into three zones: forest edge, forest intermediate and forest interior. A point-count distance sampling method was used in the bird surveys. The study recorded 7789 detections, representing 100 bird species belonging to 28 families. Pycnonotidae, Timaliidae and Nectariniidae were the dominant families overall and showed the highest number of observations recorded in the study area whereas Motacillidae showed the fewest observations. The bird species were grouped into three feeding guilds: insectivores, frugivores and others (omnivores, carnivores, nectarivores and granivores). The species richness of insectivorous birds differed significantly among the forest zones sampled (Kruskal-Wallis: α=0.05, H=10.979, d.f.=2, p=0.004), with more insectivorous birds occurring in the forest interior. No significant differences were found among the zones in the species richness of either the frugivore guild or the composite others guild. PMID:24575221

Relating the temporal change observed by AIRSAR to surface and canopy properties of mixed conifer and hardwood forests of northern Michigan

NASA Technical Reports Server (NTRS)

Dobson, M. Craig; Mcdonald, Kyle; Ulaby, Fawwaz T.; Sharik, Terry

1991-01-01

The mixed hardwood and conifer forests of northern Michigan were overflown by a 3-frequency airborne imaging radar in Apr. and Jul. 1990. A set of 10 x 10 km test sites near the University of Michigan Biological Station at Douglas Lake and within the Hiawatha National Forest in the upper peninsula of Michigan contained training stands representing the various forest species typical of forest communities across the ecotone between the coniferous boreal forest and mid-latitude hardwood and coniferous forests. The polarimetric radar data were externally calibrated to allow interdate comparisons. The Apr. flight was prior to bud-break of deciduous species and patchy snowcover was present. The Jul. flights occurred during and 2 days after heavy rain showers, and provide a unique opportunity to examine the differences in radar backscatter attributable to intercepted precipitation. Analyses show that there are significant changes in backscattering between biophysically dissimilar forest stands on any given date and also between dates for a given forest stand. These differences in backscattering can be related to moisture properties of the forest floor and the overlying canopy and also to the quantity and organizational structure of the above-ground biomass.

Post-dispersal seed removal by ground-feeding rodents in tropical peatlands, Central Kalimantan, Indonesia

PubMed Central

Blackham, Grace V.; Corlett, Richard T.

2015-01-01

Forested tropical peatlands in Southeast Asia are being rapidly converted to agriculture or degraded into non-forest vegetation. Although large areas have been abandoned, there is little evidence for subsequent forest recovery. As part of a study of forest degradation and recovery, we used seed removal experiments and rodent surveys to investigate the potential role of post-dispersal seed predation in limiting the regeneration of woody plants. Two 14-day seed removal trials were done in deforested and forested peatland habitat in Central Kalimantan, Indonesia. Seeds of Nephelium lappaceum, Syzygium muelleri, Artocarpus heterophyllus (all animal-dispersed) and Combretocarpus rotundatus (wind-dispersed) were tested. Significantly more seeds (82.8%) were removed in forest than non-forest (38.1%) and Combretocarpus had the lowest removal in both habitats. Most handled seeds were eaten in situ and little caching was observed. Six species of rodents were captured in forest and five in non-forest. The most trapped taxa were three Maxomys spp. in forest (85.5% of individuals) and Rattus tiomanicus in non-forest (74.8%). Camera traps confirmed that rodents were responsible for seed removal. Seed predation in deforested areas, which have a much lower seed rain than forest, may contribute to the low density and diversity of regenerating forest. PMID:26369444

Post-dispersal seed removal by ground-feeding rodents in tropical peatlands, Central Kalimantan, Indonesia.

PubMed

Blackham, Grace V; Corlett, Richard T

2015-09-15

Forested tropical peatlands in Southeast Asia are being rapidly converted to agriculture or degraded into non-forest vegetation. Although large areas have been abandoned, there is little evidence for subsequent forest recovery. As part of a study of forest degradation and recovery, we used seed removal experiments and rodent surveys to investigate the potential role of post-dispersal seed predation in limiting the regeneration of woody plants. Two 14-day seed removal trials were done in deforested and forested peatland habitat in Central Kalimantan, Indonesia. Seeds of Nephelium lappaceum, Syzygium muelleri, Artocarpus heterophyllus (all animal-dispersed) and Combretocarpus rotundatus (wind-dispersed) were tested. Significantly more seeds (82.8%) were removed in forest than non-forest (38.1%) and Combretocarpus had the lowest removal in both habitats. Most handled seeds were eaten in situ and little caching was observed. Six species of rodents were captured in forest and five in non-forest. The most trapped taxa were three Maxomys spp. in forest (85.5% of individuals) and Rattus tiomanicus in non-forest (74.8%). Camera traps confirmed that rodents were responsible for seed removal. Seed predation in deforested areas, which have a much lower seed rain than forest, may contribute to the low density and diversity of regenerating forest.

Sources and sinks of ozone in savanna and forest areas during EXPRESSO: Airborne turbulent flux measurements

NASA Astrophysics Data System (ADS)

Cros, B.; Delon, C.; Affre, C.; Marion, T.; Druilhet, A.; Perros, P. E.; Lopez, A.

2000-12-01

An airborne study of ozone concentrations and fluxes in the lower layers of the atmosphere was conducted over the Central African Republic (CAR) and northern Congo in November/December 1996, within the framework of the Experiment of Regional Sources and Sinks of Oxidants (EXPRESSO). The first 4 km of the atmosphere above savanna, rain forest, and the transitional area between them, were investigated with the French research aircraft Avion de Recherche Atmosphérique et de Télédétection (ARAT). Turbulent fluxes and deposition velocities of ozone were determined using the Eddy Correlation (EC) method. A specific methodology was developed to obtain accurate airborne turbulent flux measurements. This methodology is linked to the turbulence stationarity. The average values of ozone fluxes and ozone deposition velocities in the Atmospheric Boundary Layer (ABL) increase appreciably from savanna to forest. Near the ground, the ozone fluxes range between -0.115 +/-0.073 ppbv m/s above savanna and -0.350 +/-0.115 ppbv m/s above forest; for the deposition, the ranges are 0.0042 +/-0.0018 m/s and 0.015 +/-0.004 m/s. A simple empirical relationship between deposition velocity and Leaf Area Index (LAI) is proposed, giving an estimation of the deposition velocity for a whole latitudinal band. Vertical inputs of ozone to the ABL are estimated according to entrainment fluxes. The role of advection is neglected for horizontal transport of ozone in the ABL. The photochemical ozone production is deduced from the photo-stationary state deviation, and compared to the net ozone increase in the ABL during the flights performed above the forest. A tentative ozone budget based on the aircraft measurements is proposed in the ABL of the rain forest. Around noon, the photochemical production dominates with a net production of about 10 ppbv/h.

Primate community of the tropical rain forests of Saracá-Taqüera National Forest, Pará, Brazil.

PubMed

Oliveira, L C; Loretto, D; Viana, L R; Silva, J S; Fernandes, W G

2009-11-01

Brazil is the richest country in the world in terms of primate species and the Amazonian rain forest is one of the richest biomes containing 15 (ca. 90%) of the Neotropical primate genera. Although considered key elements in conservation strategies, there is only anecdotal information on primates for several protected areas within the region. Here we present new data on the community composition of the primates in the Saracá-Taqüera National Forest (429,600 ha), an actively mined, bauxite rich area, in Pará, Brazil. We used information from the literature, technical reports, museum data, and interviews conducted with agents from the Brazilian Institute of the Environment and Natural Renewable Resources (Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renováveis - IBAMA) and members of the local 'Quilombo' community. In addition, from July 2003 to June 2007, we carried out 19 field trips ranging from 10 to15 days each, amounting to a total effort of 1,230 hours and 1,420 km of censuses, resulting in 1,034 records of eight primate species (Saguinus martinsi, Saguinus midas, Saimiri sciureus, Cebus apella, Pithecia pithecia, Chiropotes sagulatus, Ateles paniscus, and Alouatta macconelli). Two other species (Cebus olivaceus and Aotus trivirgatus) were recorded only indirectly, through interviews and literature data. In all, Alouatta macconelli was the most frequently recorded species (43% of all records); while Saguinus midas and P. pithecia were the least (ca. 0.4 and 0.6% of all records). Based on our results, we discuss group sizes as well as taxonomic problems concerning the genera Pithecia and Chiropotes, for which we registered individuals displaying phenotypic geographical variation and two different forms, respectively. Despite the deforestation inherent in bauxite mining, the Saracá-Taqüera National Forest still has a remarkable richness of primate species. Our study results place this National Forest amongst the richest reserves, in terms of primate species, in the Amazon region.

Pollen-based temperature and precipitation inferences for the montane forest of Mt. Kilimanjaro during the last Glacial and the Holocene

NASA Astrophysics Data System (ADS)

Schüler, L.; Hemp, A.; Behling, H.

2014-01-01

The relationship between modern pollen-rain taxa and measured climate variables was explored along the elevational gradient of the southern slope of Mt. Kilimanjaro, Tanzania. Pollen assemblages in 28 pollen traps positioned on 14 montane forest vegetation plots were identified and their relationship with climate variables was examined using multivariate statistical methods. Canonical correspondence analysis revealed that the mean annual temperature, mean annual precipitation and minimum temperature each account for significant fractions of the variation in pollen taxa. A training set of 107 modern pollen taxa was used to derive temperature and precipitation transfer functions based on pollen subsets using weighted-averaging-partial-least-squares (WA-PLS) techniques. The transfer functions were then applied to a fossil pollen record from the montane forest of Mt. Kilimanjaro and the climate parameter estimates for the Late Glacial and the Holocene on Mt. Kilimanjaro were inferred. Our results present the first quantitatively reconstructed temperature and precipitation estimates for Mt Kilimanjaro and give highly interesting insights into the past 45 000 yr of climate dynamics in tropical East Africa. The climate reconstructions are consistent with the interpretation of pollen data in terms of vegetation and climate history of afro-montane forest in East Africa. Minimum temperatures above the frostline as well as increased precipitation turn out to be crucial for the development and expansion of montane forest during the Holocene. In contrast, consistently low minimum temperatures as well as about 25% drier climate conditions prevailed during the pre LGM, which kept the montane vegetation composition in a stable state. In prospective studies, the quantitative climate reconstruction will be improved by additional modern pollen rain data, especially from lower elevations with submontane dry forests and colline savanna vegetation in order to extend the reference climate gradient.

Lacandon Maya ecosystem management: sustainable design for subsistence and environmental restoration.

PubMed

Diemont, Stewart A W; Martin, Jay F

2009-01-01

Indigenous groups have designed and managed their ecosystems for generations, resulting in biodiversity protection while producing for their family's needs. Here we describe the agroecosystem of the Lacandon Maya, an indigenous group who live in Chiapas, Mexico. The Lacandon practice a form of swidden agriculture that conserves the surrounding rain forest ecosystem while cycling the majority of their land through five successional stages. These stages include an herbaceous stage, two shrub stages, and two forest stages. A portion of their land is kept in primary forest. This study presents the Lacandon traditional ecological knowledge (TEK) for agroforestry and quantitatively describes the plant community and the associated soil ecology of each successional stage. Also documented is the knowledge of the Lacandon regarding the immediate use of plant species and plant species useful for soil fertility enhancement. Woody plant diversity increases during the successional stages of the Lacandon system, and by the beginning of the first forest stage, the diversity is similar to that of the primary forest. In all stages, Lacandon use 60% of the available plant species for food, medicine, and raw materials. Approximately 45% of the woody plant species present in each fallow stage were thought by the Lacandon to enhance soil fertility. Total soil nitrogen and soil organic matter increased with successional stage and with time from intentional burn. Nutrient and soil nematode dynamics in shrub stages related to the presence of introduced and managed plants, indicating engineered soil enhancement by the Lacandon. The effects on biodiversity and soil ecology coupled with productivity for agricultural subsistence indicate that Lacandon TEK may offer tools for environmental conservation that would provide for a family's basic needs while maintaining a biodiverse rain forest ecosystem. Tools such as these may offer options for regional restoration and conservation efforts such as the Mesoamerican Biological Corridor in Mexico and Central America, where attainment of environmental goals must include methods to provide resources to local inhabitants.

GTAP model and database modification to better handle cropping changes on the intensive margin.

DOT National Transportation Integrated Search

2017-07-25

Previously, induced land use change estimates considered only the extensive margin; that is, adding to harvested area by converting forest or pasture to cropland. However, recent data suggests that some of the increase in global harvested area comes ...

Longer-term effects of selective thinning on microarthropod communities in a late-successional coniferous forest

USGS Publications Warehouse

Peck, R.W.; Niwa, C.G.

2005-01-01

Microarthropod densities within late-successional coniferous forests thinned 16-41 yr before sampling were compared with adjacent unthinned stands to identify longer term effects of thinning on this community. Soil and forest floor layers were sampled separately on eight paired sites. Within the forest floor oribatid, mesostigmatid, and to a marginal extent, prostigmatid mites, were reduced in thinned stands compared with unthinned stands. No differences were found for Collembola in the forest floor or for any mite suborder within the soil. Family level examination of mesostigmatid and prostigmatid mites revealed significant differences between stand types for both horizons. At the species level, thinning influenced numerous oribatid mites and Collembola. For oribatid mites, significant or marginally significant differences were found for seven of 15 common species in the forest floor and five of 16 common species in soil. Collembola were affected less, with differences found for one of 11 common species in the forest floor and three of 13 common species in soil. Multivariate analysis of variance and ordination indicated that forest thinning had little influence on the composition of oribatid mite and collembolan communities within either the forest floor or soil. Differences in microclimate or in the accumulation of organic matter on the forest floor were likely most responsible for the observed patterns of abundance. Considering the role that microarthropods play in nutrient cycling, determining the functional response of a wide range of taxa to thinning may be important to effective ecosystem management.

The World Factbook 1999

DTIC Science & Technology

1999-01-01

Arequipa, Ayacucho, Cajamarca, Callao*, Cusco, Huancavelica, Huanuco, lea, Junin, La Libertad, Lambayeque, Lima, Loreto, Madre de Dios , Moquegua...Inca (from Cusco, Madre de Dios , Apurimac), La Libertad (from La Libertad), Los Libertadores-Huari (from lea, Ayacucho, Huancavelica), Mariategui...industrial emissions; rivers polluted from raw sewage, heavy metals , detergents; deforestation; forest damage from air pollution and resulting acid rain

Insight to Global Change: EOS/SAR Mission

NASA Technical Reports Server (NTRS)

1990-01-01

This video presentation describes the methods and instrumentation used to help in determining future climate changes on Earth and explains the benefits of experimentation with synthetic aperture radar (SAR). It also gives a better understanding of the burning of fossil fuels, deterioration of the biosphere and deforestation of the rain forest which causes the greenhouse effect.

Mayan Astronomy

NASA Astrophysics Data System (ADS)

Kelley, D.; Murdin, P.

2000-11-01

The Mayas of Mexico, Belize, Guatemala and Honduras developed an urban civilization in the tropical rain forests. In their cities are many monuments, mainly stone, which contain accounts of their rulers' families, conquests, sacrifices, rituals and building programs. These are integrated into an elaborate calendrical system, which gives dates to the day. We also have pottery, painted with elabora...

Along the Rio Negro: Brazilian Children's Environmental Views and Values.

ERIC Educational Resources Information Center

Howe, Daniel C.; And Others

1996-01-01

Interviews with fifth graders living in rural and urban parts of the Brazilian Amazon region revealed that children were aware of environmental problems, believed that throwing garbage into the Rio Negro harmed the environment and violated a moral obligation, cared about environmental harm, and supported conservation of the Amazon rain forest. (BC)

Watershed hydrology. Chapter 7.

Treesearch

Elons S. Verry; Kenneth N. Brooks; Dale S. Nichols; Dawn R. Ferris; Stephen D. Sebestyen

2011-01-01

Watershed hydrology is determined by the local climate, land use, and pathways of water flow. At the Marcell Experimental Forest (MEF), streamflow is dominated by spring runoff events driven by snowmelt and spring rains common to the strongly continental climate of northern Minnesota. Snowmelt and rainfall in early spring saturate both mineral and organic soils and...

Greenhouse gas emissions versus forest sequestration in temperate rain forests—a southeast Alaska analysis

Treesearch

David Nicholls; Trista Patterson

2015-01-01

Sitka, Alaska, has substantial hydroelectric resources, limited driving distances, and a conservation-minded community, all suggesting strong opportunities for achieving a low community carbon footprint. In this research we evaluate the level of carbon dioxide (CO2) emissions from Sitka and compare this to the estimated CO2...

Nature's Advice Book

ERIC Educational Resources Information Center

Mahlin, Kathryn; Robertson, Amy

2005-01-01

What do can people learn from the world around them? Can a tree really teach something about life? Many times teachers provide students with facts about nature but fail to consider what one can learn from the natural world around them. After many months of exploring various ecosystems such as the prairie, rain forest, and desert, one of the…

Subsurface thermal and hydrological changes between forest and clear-cut sites in the Oregon Cascades

EPA Science Inventory

The Cascades of the US Pacific Northwest are a climatically sensitive area. Projections of continued winter warming in this area are expected to induce a switch from a snow-dominated to a rain-dominated winter precipitation regime with a likely impact on subsurface thermal and h...

GLOBAL EARTH OBSERVATION SYSTEM OF SYSTEMS (GEOSS) REMOTE SENSING INFORMATION GATEWAY DEMONSTRATION

EPA Science Inventory

How do forest fires in a state or country impact the health of residents, living thousands of miles away? How do we better track the effects of heavy urban rain runoff into nearby lakes to provide unprecedented access to and use of global Earth observation information to track, ...

Northeastern plateaus bioregion

Treesearch

Gregg M. Riegel; Richard F. Miller; Carl N. Skinner; Sydney E. Smith

2006-01-01

Northeastern California landscape is a mixture of vast arid basins and uplands, and forested mountain ranges interspersed with both fresh water and alkaline wetlands. The entire bioregion is significantly influenced by the rain shadow effect of the Cascade Range to the west. Three ecological unit subsections are treated in this chapter: (1) Modoc Plateau Section (M261G...

Show & Tell: A Video Column/Setting Clear Learning Purposes for ELLs

ERIC Educational Resources Information Center

Fisher, Doug; Frey, Nancy

2016-01-01

The language of school is demanding; much of the content is decontextualized and abstract, and it concerns matters that are far removed from the daily life. Students are expected to learn about rain forests and prime numbers, literary motifs, and historical events that occurred centuries ago. Consider the additional cognitive demands confronting…

Children's Learning of Number Words in an Indigenous Farming-Foraging Group

ERIC Educational Resources Information Center

Piantadosi, Steven T.; Jara-Ettinger, Julian; Gibson, Edward

2014-01-01

We show that children in the Tsimane', a farming-foraging group in the Bolivian rain-forest, learn number words along a similar developmental trajectory to children from industrialized countries. Tsimane' children successively acquire the first three or four number words before fully learning how counting works. However, their learning is…

Den use and selection by northern flying squirrels in fragmented landscapes

Treesearch

Sanjay Pyare; Winston P. Smith; Colin S. Shanley

2010-01-01

We studied den use and den-habitat selection by the Prince of Wales Island flying squirrel (Glaucomys sabrinus griseifrons) at multiple spatial scales in fragmented temperate rain-forest habitats because of the role dens play in the distribution, reproduction, and population density of this endemic subspecies. We observed differences in spatial...

Mast fruiting of large ectomycorrhizal African rain forest trees: importance of dry season intensity, and the resource-limitation hypothesis.

PubMed

Newbery, David M; Chuyong, George B; Zimmermann, Lukas

2006-01-01

Mast fruiting is a distinctive reproductive trait in trees. This rain forest study, at a nutrient-poor site with a seasonal climate in tropical Africa, provides new insights into the causes of this mode of phenological patterning. At Korup, Cameroon, 150 trees of the large, ectomycorrhizal caesalp, Microberlinia bisulcata, were recorded almost monthly for leafing, flowering and fruiting during 1995-2000. The series was extended to 1988-2004 with less detailed data. Individual transitions in phenology were analysed. Masting occurred when the dry season before fruiting was drier, and the one before that was wetter, than average. Intervals between events were usually 2 or 3 yr. Masting was associated with early leaf exchange, followed by mass flowering, and was highly synchronous in the population. Trees at higher elevation showed more fruiting. Output declined between 1995 and 2000. Mast fruiting in M. bisulcata appears to be driven by climate variation and is regulated by internal tree processes. The resource-limitation hypothesis was supported. An 'alternative bearing' system seems to underlie masting. That ectomycorrhizal habit facilitates masting in trees is strongly implied.

A new species of small-eared shrew (Mammalia, Eulipotyphla, Cryptotis) from the Lacandona rain forest, Mexico

USGS Publications Warehouse

Guevara, Lázaro; Sánchez-Cordero, Víctor; León-Paniagua, Livia; Woodman, Neal

2014-01-01

The diversity and distribution of mammals in the American tropics remain incompletely known. We describe a new species of small-eared shrew (Soricidae, Cryptotis) from the Lacandona rain forest, Chiapas, southern Mexico. The new species is distinguished from other species of Cryptotis on the basis of a unique combination of pelage coloration, size, dental, cranial, postcranial, and external characters, and genetic distances. It appears most closely related to species in the Cryptotis nigrescens species group, which occurs from southern Mexico to montane regions of Colombia. This discovery is particularly remarkable because the new species is from a low-elevation habitat (approximately 90 m), whereas most shrews in the region are restricted to higher elevations, typically > 1,000 m. The only known locality for the new shrew is in one of the last areas in southern Mexico where relatively undisturbed tropical vegetation is still found. The type locality is protected by the Mexican government as part of the Yaxchilán Archaeological Site on the border between Mexico and Guatemala.