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1.
Aim We tested whether variation in snapshots of butterfly species composition and species richness taken from one to six years apart could be interpreted as an ecologically meaningful trend or whether they might merely reflect stochasticity. Location Field research was conducted in the Toquima Range and Shoshone Mountains, Lander and Nye counties, Nevada, USA. Methods We obtained data for 49 sites in the Toquima Range from 1996 to 2002 and 39 sites in the Shoshone Mountains from 2000 to 2002. Sites spanned the gradient of local topographic and climatic conditions in those mountain ranges. Data on species composition and species richness were based on comprehensive field inventories. We calculated similarity of species composition using the Jaccard index. We conducted one‐factor repeated‐measures analyses of variance to test whether the distribution of similarity of species composition and the distribution of mean species richness depended on the number of years between inventories. Results In both mountain ranges, much less of the difference in species composition was attributable to turnover of species composition within sites over time than to spatial differences among sites. Annual species richness in the Toquima Range was more variable than in the Shoshone Mountains, but again far less of the variation in species richness was attributable to year than to differences among sites. Main conclusions Despite the fact that desert ecosystems are not expected to be highly resilient to global environmental change, there may be a time lag between deterministic environmental changes and a detectable faunal response, even in taxonomic groups that are known to be sensitive to changes in climate and vegetation. Although information on species richness and similarity of species composition are among the most practical data to collect in managed landscapes, these measures may not be highly sensitive to environmental changes over the short to moderate term.  相似文献   

2.
Hunting for willow ptarmigan (Lagopus lagopus) is a popular recreational activity in Norway, but studies of the hunters are limited. While large game management in Norway is based on sound models and research, management of small game hunters and hunting have not been subject to the same rigour. Compared to the extensive body of knowledge about ptarmigan behaviour and habitat preferences, the knowledge base on ptarmigan hunters is very limited. We surveyed the habitat preferences of 3,056 hunters to identify preferred landscape categories using pictures covering a range of landscape types. We also examined to which extent residence types and forms of hunting were related to habitat preferences. Through factor analysis, we identified three categories of hunting habitat; mountain forest, low alpine and high alpine. Mode of hunting is more important than residence status in terms of preferred habitat. Hunters using dogs preferred mountain forest and low alpine habitats more than hunters without dogs. Hunters without dogs had a higher preference than dog hunters for high alpine habitats. Hunters with mixed modes of hunting have wider habitat preferences. Residence status only affects the perception of the mountain forest habitat. The results may have implications for management as land use and place-based meanings are currently changing in many natural and rural landscapes, and hunting needs to be integrated with other recreational uses.  相似文献   

3.
Allium passeyi from Blue Creek Valley of northern Utah,Geranium toquimense from the Toquima Range of central Nevada, andPrimula capillaris from the Ruby Mountains of northeastern Nevada are described, illustrated, and compared with their relatives. The three species are narrow endemics.  相似文献   

4.
Thirteen floristic communities are recognized by numerical analysis of the vegetation of a part of the West Coast Range containing the climatic station with the highest mean annual precipitation in temperate Australia, and a variation in altitude from 400 to 1200 m. These communities form an altitude-related sequence with a perceptible break at the transition to alpine vegetation. Within rainforest three intergrading groups also form an altitudinal sequence. However, total environmental stress, as reflected in growth rates, is hypothesized to control this floristic and richness gradient. Direct and indirect gradient analysis reveals a lowland successional sequence from sedgeland to rainforest. Although some alpine communities are clearly the product of firing of others, there is no analogue of the lowland sedgelands. Fire-induced change in both alpine vegetation and rainforest can be extremely long term. Soil drainage is important in the differentiation of both lowland and alpine communities.  相似文献   

5.
Summary The Lesser Spotted Eagle, which in Central, East and South-East Europe inhabits humid lowlands and hilly ground, has been regularly observed in the Caucasus, north-west Georgia, USSR, hunting over high alpine meadows above the treeline, 2,300 to 3,100 m above sea level.  相似文献   

6.
A small 18 × 1–5 m, distinctive, teardrop‐shaped alpine tarn about 55‐cm deep with a variable schist plate rock‐silty bed, a wetland rim and surrounding snowbank community is described from a shallow depression in the headwaters of a small primary stream at 1400 m on the crest of the Rock and Pillar Range (1450 m), south‐central South Island, New Zealand. Its initiation some 2500–3000 years ago (based on radiocarbon dating of peaty material near the base of the dam front) may have been serendipitous, but the prevailing periglacial environment of the area, involving seasonal freezing of the pond surface, has probably been conducive to its maintenance and slow extension. Despite some floristic similarities, it differs from any known alpine tarns, and a request via a YouTube video has not revealed any similar features.  相似文献   

7.
The red-legged partridge is a small game species widely hunted in southern Spain. Its commercial use has important socioeconomic effects in rural areas where other agrarian uses are of marginal importance. The aims of the present work were to identify areas in Andalusia (southern Spain) where game yields for the red-legged partridge reach high values and to establish the environmental and land use factors that determine them. We analysed 32,134 annual hunting reports (HRs) produced by 6,049 game estates during the hunting seasons 1993/1994 to 2001/2002 to estimate the average hunting yields of red-legged partridge in each Andalusian municipality (n=771). We modelled the favourability for obtaining good hunting yields using stepwise logistic regression on a set of climatic, topographical, land use and vegetation variables that were available as digital coverages or tabular data applied to municipalities. Good hunting yields occur mainly in plain areas located in the Guadalquivir valley, at the bottom of Betic Range and in the Betic depressions. Favourable areas are related to highly mechanised, low-elevation areas mainly dedicated to intensive dry crops. The most favourable areas predicted by our model are mainly located in the Guadalquivir valley.  相似文献   

8.
Mule deer (Odocoileus hemionus) are widely hunted throughout western North America and are experiencing population declines across much of their range. Consequently, understanding the direct and indirect effects of hunting is important for management of mule deer populations. Managers can influence deer mortality rates through changes in hunting season length or authorized tag numbers. Little is known, however, about how hunting can affect site fidelity patterns and subsequent habitat use and movement patterns of mule deer. Understanding these patterns is especially important for adult females because changes in behavior may influence their ability to acquire resources and ultimately affect their productivity. Between 2008 and 2013, we obtained global positioning system locations for 42 adult female deer at the Starkey Experimental Forest and Range in northeast Oregon, USA, during 5-day control and treatment periods in which hunters were absent (pre-hunt), present but not actively hunting (scout and post-hunt), and actively hunting male mule deer (hunt) on the landscape. We estimated summer home ranges and 5-day use areas during pre-hunt and hunt periods and calculated overlap metrics across home ranges and use areas to assess site fidelity within and across years. We used step selection functions to evaluate whether female mule deer responded to human hunters by adjusting fine-scale habitat selection and movement patterns during the hunting season compared to the pre-hunt period. Mule deer maintained site fidelity despite disturbance by hunters with 72 ± 4% (SE) within-year overlap between summer home ranges and hunt use areas and 54 ± 7% inter-annual overlap among pre-hunt use areas and 56 ± 7% among hunt use areas. Mule deer diurnal movement rates, when hunters are active on the landscape, were higher during the hunting period versus pre-hunt or scout periods. In contrast, nocturnal movement rates, when hunters are inactive on the landscape, were similar between hunting and non-hunting periods. Additionally, during the hunt, female mule deer hourly movements increased in areas with high greenness values, indicating that mule deer spent less time in areas with more vegetative productivity. Female mule deer maintained consistent habitat selection patterns before and during hunts, selecting areas that offered more forest canopy cover and high levels of vegetative productivity. Our results indicate that deer at Starkey are adopting behavioral strategies in response to hunters by increasing their movement rates and selecting habitat in well-established ranges. Therefore, considering site fidelity behavior in management planning could provide important information about the spatial behavior of animals and potential energetic costs incurred, especially by non-target animals during hunting season. © 2020 The Wildlife Society.  相似文献   

9.
Records of official deer control operations in the Kaweka Range between 1958 and 1988 have been used to describe the pattern of official hunting, to indicate changes in hunting efficiency, and to show trends in the proportions of sika and red deer in sympatric populations. The pattern of hunting largely reflected wild animal control priorities, and to some extent the resources available. Whereas hunting effort was concentrated in Block 1 (of three) during the 1960s to protect catchment values, changes in the rationale for wild animal control and the efforts of commercial and recreational hunters in the more accessible areas led to a more even spread of the hunting effort from the early 1970s. Hunting efficiency also varied between the three h unting blocks, probably reflecting differences in the ease with which particular habitats could be hunted. A decline in hunting efficiency over the study period was interpreted as an overall decrease in the density of the deer population. The proportion of sika among the deer shot in the Kaweka Range has increased steadily from about 10-20% in the early 1960s to 70% in 1987-88. A competitive advantage over red deer because of their different digestive physiology is suggested as the main reason. The most rapid increases in the proportion of sika were associated with two Peaks in commercial venison and live-capture operations that concentrated on red deer, indicating that commercial hunting has also been a factor. It is likely that sika will continue icreasing in proportion to red deer in areas already inhabited. In addition, sika will probably continue to disperse into new areas as they competitively displace red deer.  相似文献   

10.
We examined the relationship of breeding birds to elevation across and within four adjacent mountain ranges in the central Great Basin, a cold desert in western North America. Data came from 7 years of point counts at elevations from 1,915 to 3,145 m. We focused on eight passerine species that in this region are associated frequently with Pinus monophylla–Juniperus spp. (pinyon–juniper) woodland. Mean elevation of species' presence differed significantly among mountain ranges for all species except Spizella passerina (Chipping Sparrow); all species except Spizella breweri (Brewer's Sparrow) occurred at the highest mean elevation in the Toquima Range. Observed patterns were consistent with the elevational distribution of pinyon–juniper woodlands that provide nesting and foraging habitat for these species. Across the Great Basin, driven in part by climate change, pinyon–juniper woodland is increasing in density and expanding its distribution at lower elevations. However, breeding habitat for species dependent on mature trees may not be available in expansion woodlands for several decades, and increased tree densities may have negative effects on bird species that are dependent on shrubs within open pinyon–juniper woodlands. Responses of individual species to elevation differed from the response of assemblage-level patterns. Responses to biotic and abiotic variables within guilds of birds are sufficiently diverse, and responses of individual species sufficiently heterogeneous, that one management strategy is unlikely to meet the needs of all species in the group.  相似文献   

11.
基于MaxEnt模型西南地区高山植被对气候变化的响应评估   总被引:2,自引:0,他引:2  
熊巧利  何云玲  邓福英  李同艳  余岚 《生态学报》2019,39(24):9033-9043
采用1∶100万的中国植被类型图以及19个气候环境变量数据,基于最大熵(MaxEnt)算法和ArcGIS空间分析模块构建西南地区高山植被地理分布的气候适宜性预测模型,模拟其在基准期(1960—2000年)和不同气候情景下(A2、A1B和B1)的气候适宜性分布格局,并评价其对气候变化的适应性。结果表明:MaxEnt模型分析研究区高山植被地理分布气候适宜性的适用性非常高(AUC=0.93);最暖月均温、最湿季均温、最冷月均温等温度变量是限制其地理分布的主要气候因子;研究区高山植被地理分布的气候适宜区主要集中在西藏自治区、青海省、四川省西部及云南省西北部的部分地区;完全适宜、中度适宜、轻度适宜、不适宜的面积所占总面积比例约为1∶1∶2∶5;1960—2050年研究区高山植被潜在地理分布的气候适宜性面积有不同定程度的减少;未来3种气候变化情景下高山植被地理分布对气候变化的适应性分布格局基本一致,均为不适应区所占总面积比例较大;伴随气候变化,研究区高山植被的适应性减弱,体现在其潜在地理分布对气候变化的适应区分布范围减少;海拔5000—5500m适应性较强,适应区所占面积比例最大(53%左右);3500—4500m适应性最弱,适应区所占面积比例最小(5%左右)。  相似文献   

12.
The temporal distribution of populations of aquatic macroinvertebrates have been extensively investigated in temperate arctic regions, but little information is available for alpine regions in North America. This paper describes phenology patterns of the aquatic macroinvertebrates of a high elevation wetland (3593 m) in the Green Lakes Valley, Colorado Front Range.Abundant taxa were Chironomidae (primarily Orthocladius and the limnephilid trichopteran Asynarchus curtus (Banks). Temperature patterns were related to the seasonal timing of life stages of most species. Phenology of most alpine aquatic macroinvertebrates appears to be controlled by seasonal climatic patterns, particularly temperature patterns. All chironomid species and Asynarchus curtus (Banks) had univoltine life cycles. Multi-year life cycles were not observed at this alpine site, although they have been observed at some arctic sites with colder temperature regimes than observed in this study.  相似文献   

13.
Aim Accurate inventories of biota are typically restricted to few locations within an extensive region. Accordingly, effective planning must involve some form of surrogate measures coupled with spatial modelling. We conducted a simultaneous comparison of models of both species richness and the number of rare species using three types of surrogates (indicator species, vegetation composition and structure, and topoclimate) as predictors. We evaluated each type of surrogate alone and in combination with others. Location Data for our analyses were collected from 1996–2004 in three adjacent mountain ranges in the central Great Basin (Lander and Nye counties, Nevada, USA), the Shoshone Mountains, Toiyabe Range and Toquima Range. Methods Data on species richness and species composition of butterflies and birds and measures of vegetation composition and structure were obtained in the field. Topoclimatic variables were derived by GIS from digital sources and satellite images. We used Poisson regression with Bayesian model averaging to predict species richness and the number of rare species. We compared the expected prediction success of all models on the basis of internal and external validation trials. Results Same‐taxon indicator species were the most accurate predictors of species richness and of the number of rare species of butterflies and birds. Cross‐taxon indicator species and topoclimate variables were reasonably accurate predictors of species richness of butterflies and birds and of the number of rare butterfly species. Although vegetation variables were more effective for predicting species richness and number of rare species of birds than of butterflies, they were the least accurate predictors overall. Main conclusions Although indicator species may provide the most accurate predictions of species richness, their practical value, like any surrogate measure, depends greatly on ecological considerations and land‐use context. In general, the ability to predict numbers of rare species based on any set of candidate predictors was weaker than the ability to predict species richness, which may result from the high degree of stochasticity that often characterizes distributions of rare species. Our statistical approach for objective examination of different candidate predictors can help ensure that selection of species‐richness surrogates in any system is scientifically reliable and cost‐effective.  相似文献   

14.
Public lands managed for wildlife frequently provide various forms of sanctuary to increase residency times and allow access to energetic and other habitat resources for waterfowl. The influence of sanctuary type and disturbance regime on resource use and fine-scale movements of waterfowl has not been investigated extensively using currently available transmitter technologies. We examined mallard (Anas platyrhynchos) use of various types of waterfowl sanctuary and non-sanctuary areas in the Mississippi Alluvial Valley region of eastern Arkansas, USA, during winters of 2019–2021. We deployed 105 global positioning system transmitters on mallards at 4 closed-access spatial sanctuaries on or adjacent to Dale Bumpers White River National Wildlife Refuge. We used hourly transmitter locations to examine mallard use of public sanctuary areas, public hunt areas, and private lands using integrated step selection analysis. Public sanctuary areas provided varying levels of protected status, public hunt areas allowed for varying levels of hunting intensity by duck hunters, and private lands were open to waterfowl hunting and other forms of private uses but may or may not have been hunted at any specific frequency. Mallards selected spatial sanctuary and avoided public hunt areas, other sanctuary types, and private lands during the day. In contrast, mallards selected for private lands over spatial sanctuary at night. Mallards tended to avoid areas that allowed duck hunting or used them during the night when risk of harvest mortality was removed. After the hunting season closed, mallards began using areas that previously allowed duck hunting during the day, suggesting that risk was the primary factor influencing site use. Moreover, mallards were 1.6 times more likely to use public daily hunt areas and 2.1 times more likely to use private lands potentially open to hunting during the day than spatial sanctuary 2 weeks after the close of duck hunting season in February. Spatial sanctuaries appear more effective in influencing mallard use than temporal sanctuaries or inviolate sanctuaries, which are commonly used by state and federal agencies. Partial daily, daily, or activity-specific (e.g., no hunting past noon, no hunting 3 days/week, no waterfowl hunting) closures to encourage mallard use of temporal sanctuaries do not appear to reduce the perceived harvest-related risk to mallards enough for them to view these areas as accessible or significantly increase their use.  相似文献   

15.
Predation by introduced stoats is now considered a major threat to the population viability of several New Zealand endemic bird species. Historically stoat research and management has focused on beech forests and little is known about the ecology of stoats in the alpine grasslands occurring above the natural altitudinal limit of beech forest. Several stoat control operations in beech forest valley floors in southern New Zealand assume that adjacent montane areas act as a barrier to stoat immigration. Stoats were live-trapped and radio-tracked in alpine grasslands above the Borland Burn, Fiordland National Park, during the summer and autumn of 2003 and 2004. Seventeen stoats were radio-collared and home ranges were estimated for 11 of them. These home ranges were used in a compositional analysis which showed that these stoats spent significantly more time in alpine grassland than in adjacent beech forest. Range cores calculated for six of these stoats were located high up in alpine grassland and contained very little beech forest. This means that montane areas that contain alpine grasslands are unlikely to be barriers to stoat immigration; rather they may be a source of dispersing stoats that reinvade control areas. Also, endemic animal species that inhabit alpine grasslands could be at risk from stoat predation.  相似文献   

16.
In alpine environments, flowering phenology can differ within local populations even at the same elevation. We assessed the effects of differences in flowering phenology due to snowmelt timing caused by local geographic heterogeneity on the genetic structure of a population of an alpine plant, Erythronium grandiflorum Pursh. We established a study plot of 250×70 m at 3,340 m above sea level in the Front Range of the Rocky Mountains, CO, USA. The flowering phenology was considerably influenced by snowmelt timing due to local geographic heterogeneity. Twenty-two patches of E. grandiflorum were recognized in the study plot and were classified into three phenological groups: early, middle, and late. To express the differentiation of flowering phenology among the patches, we defined phenological distance and analyzed the relationship between genetic and phenological distances. Additionally, since genetic distance is expected to co-vary with geographic distance, we also analyzed the relationship between genetic distance and geographic distance among patches. The results revealed not only that isolation by distance was present among patches, but also that the differences in snowmelt timing gave rise to phenologically distant patches of E. grandiflorum, which in turn determine the genetic structure caused by the limited pollen flow between patches.  相似文献   

17.
贡嘎山地区主要植被类型的分布   总被引:3,自引:0,他引:3       下载免费PDF全文
贡嘎山位于青藏高原东南缘横断山系大雪山脉中段,主峰海拔高7556m。该地区有维管束植物185科,869属,约2500种。其植物区系特点为:区系成分起源古老;物种分化显著,特有种丰富;成分复杂,地理替代明显。贡嘎山主要植被类型有:冷杉、云杉组成的亚高山针叶林;松、铁杉组成的中山针叶林;松、杉、柏、油杉组成的低山针叶林;铁杉、桦木、槭树组成的针叶,阔叶混交林;樟、楠、阔楠、石栎,青冈等组成的常绿阔叶林;栎、桦、槭、杨、桤等组成的落叶阔叶林;高山栎类组成的硬叶常绿阔叶林;杜鹃、柳、圆柏等组成的高山灌丛;仙人掌(Opuntia monacantha)、金合欢、羊蹄甲等组成的河谷灌丛;嵩草(Kobresia)、羊茅(Festuca ovina), 韭和风毛菊、绢毛菊、绵参(Eriophyton wallichii)等组成的高山草甸与高山流石滩稀疏植被。贡嘎山地区水平地带性植被为常绿阔叶林,它兼有我国亚热带东部和西部常绿阔叶林的特点。 贡嘎山东坡植被垂直带谱是:1.常绿阔叶林带,海拔1100—2200m。2.山地针叶、阔叶混交林带,2200—2500m。3.亚高山针叶林带,2500—3600m。4.高山灌丛草甸带,2600—4600m。5.高山流石滩稀疏植被带,4600—4900m。6.永久冰雪带,海拔4900m以上。贡嘎山西坡植被垂直带谱是:1.亚高山针叶林带,海拔2800一4000m。2.高山灌丛草甸带,4000—4800m。3.高山流右滩稀疏植被带,4800—5100m。4.永久冰雪带,海拔5100m以上。  相似文献   

18.
高山和极地植物功能生态学研究进展   总被引:10,自引:0,他引:10  
由于环境条件恶劣,所以高山地区(特别是树木分布线以上区域)和极地地区通常被认为是陆地上最为极端的生境之一,但是高山和极地区域却也拥有众多极具价值的生物资源。因此自1896年以来,作为生物进化研究中的热点和难点。高山和极地植物对生境的适应机制和策略一直倍受研究者们的关注。本文以植物生态学、植物生理学、气象学等学科资料,分析了高山和北极植物的特有生活型,并认为它是一种主要的适应机制。通过对全球主要高山和极地植物生长地的局部气候特点的分析,作者肯定了植物的特化适应现象与极端环境各因素间存在的密切关系。  相似文献   

19.
以分布于乌鲁木齐河源区天山中段不同海拔高度的四裂红景天 (Rhodiolaquadrifida) (35 0 0~ 380 5m) 及长鳞红景天 (R.gelida) (380 5~ 4 0 10m) 为试材, 通过对比分析两种红景天在一连续的海拔梯度上种内及种间叶片膜脂过氧化及抗氧化保护系统的变化, 初步探讨植物对于高山极端环境的适应机制。结果显示, 分布于海拔较高的长鳞红景天其叶片中膜脂过氧化产物丙二醛 (MDA) 的含量明显高于分布海拔较低的四裂红景天, 而两种红景天种内膜脂过氧化水平则没有随海拔升高呈现出明显差异。此外, 抗氧化保护酶CAT, POD, SOD, GR和ASAPOD 的活性与非酶促抗氧化剂ASA、GSH的含量不仅在种间存在有明显差异, 长鳞红景天中明显高于四裂红景天, 而且在两种红景天种内亦随海拔升高有不同程度地提高。表明当海拔升高时, 虽然环境条件渐趋恶劣, 对植物造成的氧化胁迫增强, 但红景天脂膜保护系统的功能亦相应加强, 从而增强了其抵抗逆境胁迫的能力。其中以过氧化物酶POD的活性变化最为显著 :在 380 5m以下海拔区, 于四裂红景天叶片中均未检测到该酶活性, 而分布海拔较高的长鳞红景天叶片中该酶活性则随海拔升高明显增强, 推测POD可能在红景天适应特殊生境中起着重要的作用, 亦可能与高海拔区长鳞红景天取代四裂红景天有关。  相似文献   

20.
Global climate and land use change are altering plant and soil microbial communities worldwide, particularly in arctic and alpine biomes where warming is accelerated. The widespread expansion of woody shrubs into historically herbaceous alpine plant zones is likely to interact with climate to affect soil microbial community structure and function; however, our understanding of alpine soil ecology remains limited. This study aimed to (i) determine whether the diversity and community composition of soil fungi vary across elevation gradients and to (ii) assess the impact of woody shrub expansion on these patterns. In the White Mountains of California, sagebrush (Artemisia rothrockii) shrubs have been expanding upwards into alpine areas since 1960. In this study, we combined observational field data with a manipulative shrub removal experiment along an elevation transect of alpine shrub expansion. We utilized next‐generation sequencing of the ITS1 region for fungi and joint distribution modelling to tease apart effects of the environment and intracommunity interactions on soil fungi. We found that soil fungal diversity declines and community composition changes with increasing elevation. Both abiotic factors (primarily soil moisture and soil organic C) and woody sagebrush range expansion had significant effects on these patterns. However, fungal diversity and relative abundance had high spatial variation, overwhelming the predictive power of vegetation type, elevation and abiotic soil conditions at the landscape scale. Finally, we observed positive and negative associations among fungal taxa which may be important in structuring community responses to global change.  相似文献   

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