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1.
The study identified seasonal habitat use by endangered adult Sakhalin taimen Hucho perryi and the environmental characteristics of their habitat (water depth, amount of riparian forest and sinuosity). Fifteen adult H. perryi with acoustic tags were tracked by towing an acoustic receiver with a canoe in the Bekanbeushi River system in eastern Hokkaido Island, Japan, during each month from late April to late November 2008. Individuals mainly used midstream (shallower than downstream) habitats in all seasons. These locations were generally characterized by relatively dense riparian forests and high sinuosity, indicating the presence of pools. In spring, individuals used habitats with less riparian forest cover compared to mean value of the river channel. From spring to autumn, adult H. perryi selected limnologically complex habitats with meandering channels. From summer to autumn, individuals selected habitats with more riparian forest cover. The inverse relationship between H. perryi detection and riparian forest area in spring was a result of seasonal defoliation in deciduous riparian forests. 相似文献
2.
塔里木河中游洪水漫溢区荒漠河岸林实生苗更新 总被引:2,自引:1,他引:1
以塔里木河中游荒漠河岸林为研究对象,2008年6月至2009年8月,对洪水漫溢区河漫滩裸地、林下及林隙三种生境植物一年生实生苗进行了调查。结果表明:实生苗更新主要依赖洪水漫溢,在非漫溢区没有发现实生苗存在;洪水降低了漫溢区的土壤盐度,更重要的是其提供了宝贵的水分条件,在时间和水量上都有效地满足了胡杨等植物种子萌发和幼株生长的水分需求;河漫滩是河岸林种子实生苗产生的基地,洪水漫溢后的河漫滩种子实生苗密度显著大于其余两生境内实生苗密度,同时该生境内物种多样性也显著高于林下和林隙生境;光照决定着漫溢区实生苗能否成林,光照不同的空间样点上,实生苗发生数量和个体生长均存在显著差异,光照强的河漫滩,实生苗发生数量较多且幼苗能保持较高的生长活力和较多的生物量积累。 相似文献
3.
In southern California, wildfire is a ubiquitous agent shaping plant communities. Although fire impacts have been widely studied
in chaparral-covered uplands, few data are available regarding fire and riparian vegetation. This study provides an example
of the impact of a severe fire on riparian habitat. Plant species found in southern California gallery forests are typically
adapted to maintaining populations following flood disturbances; we seek to determine whether structural and compositional
changes following fire here demonstrate a similar quasi-equilibrium response. We sampled 65 quadrats on 11 transects along
two streams in the Los Padres National Forest to characterize tree species size–class distributions before and after the 2002
Wolf Fire. We tested whether species exhibited differential patterns of survivorship and regeneration following the fire,
and also tested for spatial variability in mortality within the floodplain. Alnus rhombifolia dominated the pre-fire forest, but experienced severe mortality in the fire and showed very limited resprouting after 3 years.
Other prominent taxa (Populus, Salix, Quercus spp.) also lost considerable standing basal area, but had substantially greater rates of resprouting, resulting in a dramatically
altered post-fire vegetation composition and structure. Fire impacts did not vary with landform position, leading to a distinctive
homogenizing disturbance that contrasts with the spatially zoned and relatively stabilizing compositional influence that flood
events have in this same riparian setting. 相似文献
4.
Marie-Claire Fleury-Brugiere David Brugiere 《International journal of primatology》2010,31(3):383-392
The Republic of Guinea harbours the largest population of the endangered western chimpanzees Pan troglodytes verus, and the conservation of this population is regarded as a regional priority. Chimpanzees occur in 3 of the 5 protected areas
in Guinea but their conservation status is unknown. We conducted a chimpanzee census in 2001–2002 in the Haut Niger National
Park (HNNP), the largest protected area in the country. We counted nests along a total of 103.83 km of transects in the Mafou
forest, 1 of the 2 core areas of the park. We recorded a total of 823 nests, of which 38.1% were located in gallery forests,
although this habitat type covers only 4.2% of the study site. Using a site-specific mean nest decay rate of 194 days, we
estimated the mean density of chimpanzees in the study area at 0.87 weaned individuals/km2, the highest density recorded in
any West African protected area. A survey conducted in 2008–2009 by other authors in the Mafou forest suggests that the chimpanzee
population remained stable over the last 6 yr. Given the significance of the chimpanzee population of the HNNP at the national
and international levels, we provide recommendations for its conservation over the long term. Our results highlight the importance
of gallery forests as key habitat for chimpanzees in the savannah biome. We therefore recommend that more attention be paid
to the conservation of this habitat in land management and conservation planning schemes. In particular, we recommend setting
aside gallery forests as ecological corridors between nearby protected areas to maintain exchange between distant chimpanzee
populations. 相似文献
5.
Nancy Nthenya Moinde-Fockler Nicholas Otienoh Oguge Genesio Mugambi Karere Daniel Otina Mbaruk Abdalla Suleman 《Biodiversity and Conservation》2007,16(4):1161-1173
Seventy-three forest patches were assessed to determine the effects of human and natural impact on native forests along the
Lower Tana River flood plains in Kenya between January and March 2001. Seventeen of these forests were within the Tana River
Primate National Reserve (TRPNR) while 56 were outside the protected area. Cultivation and dyke construction had the most
devastating human impact, which involved partial or complete forest clearing resulting in further fragmentation of forest
patches [Suleman MA, Wahungu GM, Mouria PK, Karere GM, Oguge N, Moinde NN (2001) Tana River primate census and forest evaluation.
A report to Kenya Wildlife Services]. Natural impacts were either die back or flooding, which appeared to cause progressive
degradation of forest structure and biodiversity. Overall, forest area in the Lower Tana significantly reduced by 34.5% (P < 0.001) over a 21-year period. Forest loss was greater outside the reserve (38%) than inside (29.2%) reiterating the significant
role played by this protected area in habitat and species conservation. Continued forest loss increases extinction risks for
the endemic primate species the Tana River Red Colobus (Procolobus rufomitratus) and the Crested Mangabey sub-species (Cercocebus galeritus galeritus). Initiation of community conservation programmes outside the reserve and introduction of sustainable micro-economic projects
were recommended to enhance sustainable livelihoods and the environment. 相似文献
6.
Patricia J. Happe Kurt J. Jenkins Rebecca M. Mccaffery Jeffrey C. Lewis Kristine L. Pilgrim Michael K. Schwartz 《The Journal of wildlife management》2020,84(2):344-358
Monitoring population performance in the years following species reintroductions is key to assessing population restoration success and evaluating assumptions made in planning species restoration programs. From 2008–2010 we translocated 90 fishers (Pekania pennanti) from British Columbia, Canada, to Washington's Olympic Peninsula, USA, providing the opportunity to evaluate modeling assumptions used to identify the most suitable reintroduction areas in Washington and enhance understanding of fisher habitat associations in the late-successional forest ecosystems in the coastal Pacific Northwest. From 2013–2016, we deployed 788 motion-sensing cameras and hair (DNA)-snaring devices distributed among 263 24-km2 primary sampling units across the Olympic Peninsula. Our objectives were to determine whether occupancy patterns of the reestablishing population supported assumptions of the initial habitat assessment models, whether the population had expanded or shifted in distribution since the initial reintroductions, compare physical habitat attributes among land-management designations, and determine whether the founding fishers had successfully reproduced. We predicted that site occupancy by fishers would be associated with landscapes characterized by high proportional coverage of dense forest canopies and medium-sized and large trees, a diversity of stand structural classes, and area near the administrative boundary separating wilderness from more intensively managed forest lands. We detected fishers across designated wilderness, federal lands outside of wilderness, and other land designations in proportion to land availability on the Peninsula. We found negligible support for predictions that occupancy by fishers was associated with percent forest cover, tree-size class, or structural class diversity. Rather, occupancy was strongly associated with lands near the wilderness boundary on both sides. We speculate that the boundary between wilderness and more intensively managed forest lands provided fishers with the most suitable prey in proximity to contiguous expanses of low- to mid-elevation late-successional forests that provided optimal resting, denning, and security values. Occupancy patterns shifted toward the west and south along a precipitation gradient during the study, indicating that population distribution had not yet stabilized 5–8 years following translocation. Genetic results indicated that ≥2 generations of fishers have been produced on the Peninsula. Annual occupancy rates across the Peninsula (0.08–0.24) were lower than in other previously studied and established fisher populations, indicating that not all habitat was fully occupied or that initial estimates of the extent of habitat was overestimated. The strong selection fishers exhibited for wilderness edge and weak selection against extensive forested wilderness areas suggested that habitat managers should strive for maintaining a suitable interspersion of required forest structures and biotic habitat components, such as prey resource availability. © 2019 The Wildlife Society. 相似文献
7.
Riparian vegetation, an important mediator of land–water interactions, provides habitat for animals and other organisms; however,
riparian vegetation zones have been altered by agricultural and urban development in Korea. This riparian vegetation survey
was conducted to obtain information vital for the ecological restoration and management of the Korean Geum River ecosystem.
At 100 study sites, along the Geum River, we recorded the vegetation of the Geum riparian zone. We then surveyed the riparian
vegetation associations in the area and overlaid those areas corresponding to trees, shrubs, perennial herbs, annual herbs,
exotic plants, cultivated lands, and damaged lands on a geographical map. We also reconstructed the cross-sectional landscape.
The mean values of vegetation diversity, exotic plant area (%), annual plant area (%), and species richness were 6.47 ± 0.26,
5.44 ± 1.01, 11.98 ± 1.20, and 22.69 ± 0.93, respectively. The landscape elements of the herbaceous plants were more spread
out, compared with those of the woody plants, and 23 sites were composed strictly of herbs. Our results indicate significant
differences in vegetation structure among the study sites. For example, at some sites, exotic plants, cultivated lands, and
damaged lands dominated the landscape comprising 25.7, 62, and 68.9%, respectively, of the area. The riparian landscape reference
model suggested by these results may be applied to studies of other well-conserved riparian zones. We propose that the material
pathways and transport of organisms from land to water at Geum River depend on the patchy distribution of these diverse landscape
elements. 相似文献
8.
Jenna E. Stanek Shannon E. Mcneil Diane Tracy John R. Stanek Jeffrey A. Manning Murrelet D. Halterman 《The Journal of wildlife management》2021,85(4):782-793
The western distinct population segment of yellow-billed cuckoo (Coccyzus americanus; western cuckoo) has been extirpated from most of its former breeding range in the United States because of widespread loss and degradation of riparian cottonwood (Populus spp.)-willow (Salix spp.) forests. Restoration and management of breeding habitat is important to the recovery of this federally threatened species, and identification of high-quality breeding habitat can help improve the success of recovery. In 2005, the Lower Colorado River Multi-Species Conservation Program, a long-term, multi-agency effort, was initiated to maintain and create wildlife habitat within the historical floodplain of the lower Colorado River (LCR) for federally endangered and threatened species, including western cuckoos. We conducted an empirical, multi-scale field investigation from 2008–2012 to identify habitat characteristics selected by nesting western cuckoos along the LCR. Multiple logistic regression models revealed that western cuckoos selected nest sites characterized by increased densities of small, native, early successional trees measuring 8–23 cm diameter at breast height, and lower diurnal temperature compared to available habitat in restoration and natural forests. Nesting cuckoos selected sites with increased percent canopy closure, which was also important for nest success in restoration sites along the LCR. Our results show habitat components selected by nesting western cuckoos in restoration and natural riparian forests and can help guide the creation, enhancement, and management of riparian forests with habitat conditions necessary to promote nesting of western cuckoos. © 2021 The Wildlife Society. 相似文献
9.
Abundance and Production of Riparian Trees in the Lowland Floodplain of the Queets River, Washington 总被引:1,自引:1,他引:0
Riparian zones associated with alluvial rivers are spatially dynamic, forming distinct vegetative mosaics that exhibit sharp
contrasts in structure and processes related to the underlying biophysical template. The productivity of riparian plants,
especially trees, influences streamside community characteristics as well as the forms and fluxes of organic matter to adjacent
streams – thereby strongly impacting patterns of channel morphology, water flow, sedimentation, and habitat in rivers. As
part of a comprehensive investigation of riparian dynamics in coastal rain forest rivers of the Pacific Northwest (USA), we
examined riparian tree abundance (density, basal area, and biomass) and rates of production (basal area growth [BAI] and bole
wood biomass increase [P]) of seven common species – red alder (Alnus rubra), Sitka spruce (Picea sitchensis), bigleaf maple (Acer macrophyllum), western hemlock (Tsuga heterophylla), black cottonwood (Populus trichocarpa), vine maple (Acer circinatum) and willow (Salix spp.) – in the lowland floodplain of the Queets River (Olympic National Park), Washington. Measurements were made annually
for three years (1999 – 2001) in 16 permanent plots on three biophysical templates that formed a toposequence – active floodplain,
young terrace and mature terrace. Stem density was highest in the active floodplain (∼27,000 stems/ ha), decreasing in the
young terrace (∼2,700 stems /ha) and the mature terrace (∼500 stems/ha). Basal area and total stem biomass were lowest in
the active floodplain (∼16 m2/ha and ∼18 Mg dry weight/ha, respectively) and higher on the young terrace (∼32 m2/ha and ∼134
Mg dry weight/ha) and on the mature terrace (∼69 m2/ha and ∼540 Mg dry weight /ha). Total plot-scale BAI was not significantly
different among the physical templates with mean values ranging from approximately 1.4 (low terrace) to approximately 2.8
m2/ha/y (active floodplain). In contrast, P was significantly higher on the mature terrace (10.3 Mg/ha) than the active floodplain
(3.2 Mg/ha) but there was no significant difference between young terrace (6.5 Mg/ha) and mature terrace. For the entire Queets
River floodplain (57 km2 over 77 km of river length), the mature terrace contributed 81% of the total annual production (28,764 Mg) whereas the active
floodplain and young terrace accounted only for 5 and 14%, respectively. Overall, we show that riparian trees grow quickly
in this coastal Pacific Northwest system and that the older riparian forests on mature terraces are the main contributors
to stem production at the plot and floodplain scales for at least 350 years after stand initiation. This suggests that, in
combination with the rapid lateral migrations of many alluvial rivers, the older riparian forests on those terraces are important
and sustained sources of organic matter (especially large woody debris, LWD) that, over decades to centuries, shape the character
of coastal rivers in the Pacific Northwest. 相似文献
10.
Determination of the direct causal factors controlling wildfires is key to understanding wildfire–vegetation–climate dynamics
in a changing climate and for developing sustainable management strategies for biodiversity conservation and maintenance of
long-term forest productivity. In this study, we sought to understand how the fire frequency of a large mixedwood forest in
the central boreal shield varies as a result of temporal and spatial factors. We reconstructed the fire history of an 11,600-km2 area located in the northwestern boreal forest of Ontario, using archival data of large fires occurring since 1921 and dendrochronological
dating for fires prior to 1921. The fire cycle decreased from 295 years for the period of 1820–1920 to approximately 100 years
for the period of 1921–2008. Spatially, fire frequency increased with latitude, attributable to higher human activities that
have increased fragmentation and fire suppression in the southern portion of the study area. Fire frequency also increased
with distance to waterbodies, and was higher on Podzols that were strongly correlated with moderate drainage and coniferous
vegetation. The temporal increase of fire frequency in the central region, unlike western and eastern boreal forests where
fire frequency has decreased, may be a result of increased warm and dry conditions associated with climate change in central
North America, suggesting that the response of wildfire to global climate change may be regionally individualistic. The significant
spatial factors we found in this study are in agreement with other wildfire studies, indicating the commonality of the influences
by physiographic features and human activities on regional fire regimes across the boreal forest. Overall, wildfire in the
central boreal shield is more frequent than that in the wetter eastern boreal region and less frequent than that in the drier
western boreal region, confirming a climatic top-down control on the fire activities of the entire North American boreal forest. 相似文献
11.
Gilbert Proulx 《Acta theriologica》2006,51(3):275-282
This study assessed the possibility of predicting the distribution of potential winter habitats for fisherMartes pennanti Erxleben, 1777 in central interior British Columbia (BC) with the BC Vegetation Resources Inventory (VRI) dataset used to
produce forestry maps. I predicted that fisher winter habitat would correspond to coniferous or coniferous-deciduous stands
with the following characteristics: (1) absence of disturbance, (2) >- 80 years old, (3) mature and old forest structural
stages, (4) ≥ 20 m2·ha-1 basal area in mature trees, (5) ≥ 30% canopy closure, (6) shrub cover ≥ 20%, and (7) diameter at breast height ≥ 27.5 cm.
I allocated weight values to these criteria to classify map polygons into excellent-, high-, medium-, and low- quality habitats,
and produce predictive maps of winter habitat use by fishers. I tested predictive maps in the field by snow-tracking along
27 transects (44.2 km) in winter 2003–2004, and 16 transects (31.4 km) in winter 2004–2005. A total of 89 tracks were recorded
during both years. The proportion of fisher tracks within each polygon type was significantly different from random (p < 0.001). The majority of tracks (> 83%) were in structurally complex coniferous stands. This study showed that it is possible
to predict the distribution of potential winter habitats for fisher in central interior British Columbia using simple habitat
criteria and the VRI dataset. This study’s query may be used in other regions with similar vegetation composition to identify
forests be inhabited by fishers in winter, and develop effective conservation programs in managed landscapes. 相似文献
12.
C. Fonseca 《European Journal of Wildlife Research》2008,54(2):361-366
Research was conducted on habitat selection by the wild-boar population in the Carpathian foothills, southeastern Poland.
In two forest districts (Bircza and Krasiczyn) with a total area of forests of 47,000 ha, 21 line transects were designated
(total length, 284 km). In February 2001, tracks that wild boar left during the day were counted on five subsequent days.
Using a car mileage meter and forest maps, the locations of tracks in seven forest types, forest meadows and agricultural
fields situated inside the forests were determined. The Bailey’s test was applied to calculate the boars’ preference for each
forest type and non-forest areas. Spatial distribution of 284 wild-boar tracks shows that the animals do indeed prefer European
beech–hornbeam Fagus silvatica–Carpinus betulus forest and avoid silver fir Abies alba forest. The hypothesis raised is that in the European beech–hornbeam forests, there are foraging areas and bedding sites
crucial for the animals. 相似文献
13.
George B. Chuyong David Kenfack Kyle E. Harms Duncan W. Thomas Richard Condit Liza S. Comita 《Plant Ecology》2011,212(8):1363-1374
Niche differentiation with respect to habitat has been hypothesized to shape patterns of diversity and species distributions
in plant communities. African forests have been reported to be relatively less diverse compared to highly diversed regions
of the Amazonian or Southeast Asian forests, and might be expected to have less niche differentiation. We examined patterns
of structural and floristic differences among five topographically defined habitats for 494 species with stems ≥1 cm dbh in
a 50-ha plot in Korup National Park, Cameroon. In addition, we tested for species–habitat associations for 272 species (with
more than 50 individuals in the plot) using Torus translation randomization tests. Tree density and basal area were lowest
in areas with negative convexity, which contained streams or were inundated during rainy periods and highest in moist well-drained
habitats. Species composition and diversity varied along the topographical gradient from low flat to ridge top habitats. The
low depression and low flat habitats were characterized by high diversity and similar species composition, relative to slopes,
high gullies and ridge tops. Sixty-three percent of the species evaluated showed significant positive associations with at
least one of the five habitat types. The majority of associations were with low depressions (75 species) and the fewest with
ridge tops (8 species). The large number of species–habitat associations and the pronounced contrast between low (valley)
and elevated (ridgetop) habitats in the Korup plot shows that niche differentiation with respect to edaphic variables (e.g.,
soil moisture, nutrients) contributes to local scale tree species distributions and to the maintenance of diversity in African
forests. 相似文献
14.
The ‘enemy release hypothesis’ argues when a species is introduced to a novel habitat, release from regulation by herbivores
results in increased vigor, abundance, and distribution. The invasive Asian shrub Lonicera maackii appears to benefit from an absence of arthropod herbivores in North America. We assessed the incidence, amount, and type
of herbivory occurring on L. maackii in forest edge and interior habitats and investigated differences in timing of damage. In October 2008, leaves were sampled
from shrubs in forest interior and edge habitat from 8 sites in Ohio. In 2009, sampling was repeated at 3 sites in spring,
summer, and fall with a distinction made between long and short branches. Leaf area removed averaged 1.83% across the 8 populations
in 2008 and 3.09% across the 3 populations in 2009, with forest edge plants receiving slightly more damage than forest interior
plants in 2008. Additionally, long shoots received more damage than short shoots in 2009. Damage incidence was also higher
in the edge habitat and on long shoots compared to short shoots. As measured in 2009, damage accumulated steadily throughout
the season. Chewing was the most prevalent type of damage (76. 8%) and low level of pathogen infection was observed (4.81%).
Results indicate that levels of herbivory experienced by L. maackii are relatively consistent across sites, vary slightly with habitat and branch identity, but are likely too low to impact
fitness of shrubs. These findings indicate that low amounts of arthropod herbivory occur for L. maackii across its introduced range, which may contribute to its invasive success. 相似文献
15.
Changes in biota along a dry-land river in northwestern Zimbabwe: declines and improvements in river health related to land use 总被引:1,自引:0,他引:1
Albert Chakona Crispen Phiri Tendayi Chinamaringa Nikite Muller 《Aquatic Ecology》2009,43(4):1095-1106
Macroinvertebrates were sampled from 15 sites along a dry-land river in northwestern Zimbabwe to assess biotic responses to
land use changes along the course of the river. The headwater sites were protected by a riparian corridor of native forest,
but this was replaced by intensive subsistence agriculture in the mid-reaches while the lower reaches were located within
a protected wildlife area with diverse and wide riparian forests. Canonical correspondence analysis indicated that intensive
agricultural activities within the mid-reaches caused severe degradation of the stream physical habitat through increased
fine sediment deposition. This coincided with a significant decline in macroinvertebrate richness, diversity, and abundance
at the agriculturally impacted mid-reach sites. The presence of wide riparian zones at the lower river sites resulted in significant
improvements in stream physical habitat quality, and this was paralleled by significant recovery or reappearance of taxa that
had disappeared from the mid-reaches. We suggest that restoration of the riparian vegetation within the mid-reaches of the
Nyaodza River would lead to improved physical habitat and biotic health of this dry-land river. 相似文献
16.
Mechanisms of Riparian Cottonwood Decline Along Regulated Rivers 总被引:1,自引:1,他引:0
Decline of riparian forests has been attributed to hydrologic modifications to river flows. However, little is known about the physiological and structural adjustments of riparian forests subject to modified flow regimes, and the potential for forest restoration using historic flow regimes is poorly understood. In this paired river study, we compared hydrology, water relations, and forest structure in cottonwood-dominated floodplains of the regulated Green River to those of the unregulated Yampa River. We measured floodplain groundwater levels, soil water availability, cottonwood xylem pressure (Ψxp), and leaf-level stomatal conductance (gs) to assess current impacts of river regulation on the water status of adult cottonwoods. We also simulated a flood on the former floodplain of the regulated river to evaluate its impact on cottonwood water relations. Canopy and root structure were quantified with estimates of cottonwood leaf area and percent live canopy and root density and biomass, respectively. Regulation of the Green River has lowered the annual peak flow yet raised minimum flows in most years, resulting in a 60% smaller stage change, and lowered soil water availability by as much as 70% compared to predam conditions. Despite differences in water availability, daily and seasonal trends in Ψxp and gs were similar for cottonwoods on the regulated and unregulated rivers. In addition, soil water added with the experimental flood had little effect on cottonwood water relations, contrary to our expectations of alleviated water stress. Green River cottonwoods had 10%–30% lower stand leaf area, 40% lower root density, and 25% lower root biomass compared with those for Yampa River cottonwoods. Our results suggest that water relations at the leaf and stem level are currently similar for Yampa and Green River trees due to structural adjustments of cottonwood forests along the Green River, triggered by river regulation. 相似文献
17.
18.
Pellet counts have been used to measure habitat selection of a variety of ungulate species often under the assumption that
this method gives an unbiased sample of the true distribution of the species among habitats. The validity of this method has
been questioned and comparisons with other methods have sometimes showed divergent results. We tested the validity of pellet
group distribution as a tool for habitat selection studies by comparing the distribution of moose pellet groups in four different
forest age categories (forest age <30, 31–60, 61–90, >90 years) and mire with GPS positions from collared moose (Alces alces). Sample plots (n = 531) were cleaned from pellet during the fall 2007 and the number of new pellet groups were counted in spring 2008, thus
resulting in a defined period of accumulation. In addition, pellet groups were counted in paired, uncleaned, control plots.
GPS data from 15 collared moose monitored during the same period were used for comparison with habitat composition and distribution
of pellet groups. Both the distribution of pellet groups and GPS positions differed significantly from the habitat composition
within the study area. Young forest stands (<30 years) were significantly more used than both forests >30 years and mire.
The selection by moose, as calculated by Manly’s alpha, showed identical ranking among habitat classes for cleaned sample
plots and GPS data whereas uncleaned plots showed a shifted rank order for two of the habitat classes. We conclude that pellet
group counts can be used to accurately predict habitat use for moose during winter. 相似文献
19.
In wet eucalypt forest with a rainforest understorey the vegetation adjacent to first order streams does not form a distinct
riparian strip. This study investigated the riparian response of terrestrial ground-dwelling beetles adjacent to four such
streams in Tasmania, Australia. Beetle assemblages varied more between the four sites than they did with distance from stream
within sites, where they exhibited a measurable but subtle riparian response. The extent of the riparian zone varied between
the four study sites, with a 1–5 m riparian zone at three sites and a gradually changing community up to 50–100 m upslope
at one site. There was a trend for greater between plot variability immediately adjacent to the streams, possibly because
this is a more highly disturbed environment. None of the habitat variables measured were consistently associated with riparian
or upslope assemblages of beetles, probably explaining the subtlety of the beetles’ riparian response. Forest conservation
efforts for terrestrial species should not necessarily be focused on the riparian zone in preference to upslope areas. 相似文献
20.
Agricultural practices lead to losses of natural resources and biodiversity. Maintaining forests alongside streams (riparian forest strips) has been used as a mechanism to minimize the impact of clearing for agriculture on biodiversity. To test the contribution of riparian forest strips to conserve biodiversity in production landscapes, we selected bats as a biodiversity model system and examined two dimensions of diversity: taxonomic and functional. We compared bat diversity and composition in forest, with and without stream habitat, and in narrow forest riparian strips surrounded by areas cleared for agriculture. We tested the hypothesis that riparian forest strips provide potential conservation value by providing habitat and serving as movement corridors for forest bat species. Riparian forest strips maintained 75% of the bat species registered in forested habitats. We found assemblage in sites with riparian forest strips were dominated by a few species with high abundance and included several species with low abundance. Bat species assemblage was more similar between sites with streams than between those sites to forests without stream habitat. These results highlight the importance of stream habitat in predicting presence of bat species. We registered similar number of guilds between forest sites and riparian forest strips sites. Relative to matrix habitats, stream and edge habitats in riparian forest strips sites were functionally more diverse, supporting our hypothesis about the potential conservation value of riparian forest strips. Results from this study suggest that maintaining riparian forest strips within cleared areas for agricultural areas helps conserve the taxonomic and functional diversity of bats. Also, it provides basic data to evaluate the efficacy of maintaining these landscape features for mitigating impacts of agricultural development on biodiversity. However, we caution that riparian forest strips alone are not sufficient for biodiversity maintenance; their value depends on maintenance of larger forest areas in their vicinity. 相似文献