应用红外相机数据研究动物活动节律——以广东车八岭保护区鸡形目鸟类为例

动物活动节律和时间生态位分化是动物行为在时间维度的分布, 是对时间资源利用的重要体现。动物活动节律受到环境因素和种间作用的影响, 因此, 了解动物活动节律以及时间生态位有助于揭示群落中同域分布物种时间资源利用的差异及共存机制。近10多年来, 红外相机技术在国内外野生动物监测研究中得到广泛应用, 积累了大量有时间记录的动物行为数据, 极大地促进了动物活动节律和时间生态位分化的深入研究。本文对动物活动节律研究以及应用红外相机数据研究动物活动节律的方法进行梳理, 采用核密度估计方法, 利用广东车八岭国家级自然保护区的红外相机监测数据, 分析了鸡形目鸟类的活动节律, 以阐述单物种和多物种的活动节律以及种间作用对动物日活动节律的影响。研究结果表明车八岭保护区白鹇(Lophura nycthemera)、白眉山鹧鸪(Arborophila gingica)和灰胸竹鸡(Bambusicola thoracica)等3个鸡形目物种之间存在不同程度的竞争, 物种间的日活动节律呈现中等程度的重叠。最后, 针对动物活动节律分析方法应用的建议及影响因素进行讨论, 希望为国内动物活动节律研究提供参考。     

基于红外相机对云南腾冲高黎贡山云猫的调查

云猫(Pardofelis marmorata)在中国分布狭窄、种群稀少, 目前尚缺少有关其调查与研究的报道。通过红外相机分析野生动物的空间分布以及日活动节律, 有助于了解濒危物种的生态学特征, 为保护管理提供科学依据。我们于2014年4月至2021年5月在云南高黎贡山国家级自然保护区腾冲辖区34个位点放置红外相机进行监测。基于监测数据分析了云猫的空间分布, 并利用核密度估计方法(kernel-density estimation)对云猫与豹猫(Prionailurus bengalensis)的日活动节律进行了比较。通过31,462个相机日的监测, 共获得230个云猫的独立探测事件。探测数据显示: 云猫在研究区域内主要分布于海拔2,300‒3,100 m保存完好的常绿阔叶林中。记录到的云猫主要出现在白天, 于6:00‒11:00和14:00‒19:00活动最为频繁。在云猫记录密集的北部地区, 同域分布的豹猫表现出明显的夜行性, 而在南部地区则倾向于晨昏活动, 与云猫活动节律的重叠度较低。腾冲高黎贡山云猫的相对多度指数明显高于低纬度的热带地区, 对该区域云猫进行更为深入的研究对于了解与保护此物种至关重要。     

Creation of a nature reserve, its effects on hunting management and waterfowl distribution in the Camargue (southern France)

The eastern portion of the Camargue in southern France is divided into two parts: a natural wetland area of 2800 ha and an agricultural area of 5045 ha. In 1984 and 1989, a new protected area (1000 ha) was created on two contiguous former hunting estates. Analysis of aerial photographs (1968–1998) in conjunction with a field survey revealed, from 1984 to 1998, an increase of management for waterfowl hunting in natural wetlands located on the periphery of the new reserve, and a similar increase in the agricultural area amongst residual wetlands and former rice fields. Based on monthly aerial censuses, the size of the waterfowl population in the winter increased in this part of the delta by a factor of 3.8 following the creation of the reserve. Our results suggest that the creation of a reserve on former hunting estates resulted in greater attractiveness for ducks but also in the development of commercial hunting activity around the edge. This development increased fragmentation and uniformity of natural areas, including the loss of the unique Cladium mariscus habitat in the Camargue and resulted in the spatial expansion of waterfowl hunting areas in agricultural areas. It is associated with an increase in financial profit from waterfowl hunting. Our study highlights unexpected costs for nature conservation associated with the creation of a reserve. It illustrates the need for new models of wetland conservation where protection goals are not restricted to reserves, but also integrate conservation and economic development outside the protected areas.     

中国云豹种群分布现状与关键栖息地信息更新

云豹(Neofelis nebulosa)是中国大型猫科动物中对森林生态系统依赖性最高的物种。中国作为云豹的主要分布区, 由于长期以来缺乏深入研究和有效保护, 在盗猎、森林采伐、土地利用变化等威胁因素的共同作用下, 云豹在中国的分布范围和种群数量近数十年来均大幅缩减, 其分布现状亟需全面评估。本研究系统检索和查阅了国内1950年以来的云豹标本、野外调查记录、地方志、新闻报道等直接证据, 整理了中国各省级行政区内云豹记录存在的年代; 基于2010-2020年国内55个地区的红外相机监测数据, 结合同期研究文献中记录的中国云豹确认分布位点, 校准了已发表的云豹栖息地适合度模型, 并在此基础上叠加保护地和行政区划图层, 根据2010-2020年间森林覆盖率的减量评估云豹栖息地适合度的变化, 以识别我国的云豹关键栖息地和保护优先区。结果显示, 1950-2009年, 我国的云南、西藏、四川、陕西、甘肃、重庆、贵州、广西、广东、海南、湖北、湖南、安徽、江西、浙江、福建以及台湾共17个省级行政区有云豹分布, 但其中12个迄今已超过20年无确凿记录, 且目前仅在云南省和西藏自治区仍有云豹记录延续。当前我国大陆地区云豹潜在栖息地总面积64,093 km², 分别位于9个连续的栖息地斑块中, 其中3个为跨境斑块。2010-2020年间, 我国境内共在5个自然保护区的10个样区记录到云豹, 全部位于西藏东南部以及云南西部和南部的2个跨境栖息地斑块(即“喜马拉雅-横断山脉西侧-若开山脉”和“无量山南麓-安南山脉”)的边缘。2010-2020年间, 这两个斑块在中国境内区域的年均森林覆盖率减量(0.84%)小于境外(1.57%)。从本研究的结果推断, 中国目前确认分布的云豹种群极有可能维持在跨境分布的生境中, 面临内部和跨境的双重挑战。相关保护地应有针对性地加强反盗猎执法, 并开展栖息地恢复工作以提升云豹栖息地质量与斑块连通性, 同时与周边分布区国家开展跨境保护合作, 为现有云豹种群的长期生存和发展提供必要基础。     

基于红外相机数据评估华南地区豹猫的种群密度和活动节律

可靠的种群密度数据对野生动物的保护和管理十分重要。豹猫(Prionailurus bengalensis)是中国分布最广且常见的猫科动物, 但野生种群密度估算的研究并不多。本研究于2020年6月至2021年5月在香港新界嘉道理农场暨植物园开展红外相机调查, 利用空间标记-重捕法估算当地豹猫的种群密度并用核密度估计方法分析其活动节律。本次调查以网格方式布置红外相机, 在约1.5 km²的研究范围之内设置了19个相机位点, 每个位点安装2台相机以获取豹猫身体两侧花纹来进行个体识别。连续12个月调查共捕获113次有效的豹猫拍摄事件, 当中仅61次事件的照片足够清晰以进行个体识别。基于种群封闭的要求, 我们以2个月为单位将12个月的数据分为6个采样期去分析豹猫种群密度, 结果显示仅两个采样期的估算值最为准确, 分别为0.64 ± 0.31 (0.26-1.55)只/km²和0.87 ± 0.48 (0.31-2.40)只/km², 是已知全球豹猫密度最高的地点之一。结果还发现, 雨季研究地点的豹猫并无明显的日活动节律, 在旱季则偏夜行-晨昏行性多一些, 但也有一定的日间活动; 雨季和旱季的日活动节律无显著差异。本研究是首次以个体识别配以空间标记-重捕模型对中国大陆地区豹猫种群密度调查的研究; 我们也提出一些关于红外相机架设方法的建议, 以提高照片个体识别的准确度并增加重捕次数, 最后提高密度估算的准确度。本研究也进一步证明豹猫适应性极强, 在活动节律上表现出极高的可塑性, 在严格保护下可以恢复健康的种群。     

Zoning has little impact on the seasonal diel activity and distribution patterns of wild boar (Sus scrofa) in an UNESCO Biosphere Reserve

Understanding the spatio‐temporal distribution of ungulates is important for effective wildlife management, particularly for economically and ecologically important species such as wild boar (Sus scrofa). Wild boars are generally considered to exhibit substantial behavioral flexibility, but it is unclear how their behavior varies across different conservation management regimes and levels of human pressure. To analyze if and how wild boars adjust their space use or their temporal niche, we surveyed wild boars across the core and buffer zones (collectively referred to as the conservation zone) and the transition zone of a biosphere reserve. These zones represent low and high levels of human pressure, respectively. Specifically, we employed a network of 53 camera traps distributed in the Schaalsee UNESCO Biosphere Reserve over a 14‐month period (19,062 trap nights) and estimated circadian activity patterns, diel activity levels, and occupancy of wild boars in both zones. To account for differences in environmental conditions and day length, we estimated these parameters separately for seven 2‐month periods. Our results showed that the wild boars were primarily nocturnal, with diurnal activity occurring dominantly during the summer months. The diel activity patterns in the two zones were very similar overall, although the wild boars were slightly less active in the transition zone than in the conservation zone. Diel activity levels also varied seasonally, ranging from 7.5 to 11.0 h day⁻¹, and scaled positively with the length of the night (R ² = 0.66–0.67). Seasonal occupancy estimates were exceptionally high (point estimates ranged from 0.65 to 0.99) and similar across zones, suggesting that the wild boars used most of the biosphere reserve. Overall, this result suggests that different conservation management regimes (in this case, the zoning of a biosphere reserve) have little impact on wild boar behavior. This finding is relevant for wildlife management in protected areas where possibly high wild boar densities could interfere with conservation goals within these areas and those of agricultural land use in their vicinity.     

High genetic and morphological diversity despite range contraction in the diploid Hieracium eriophorum (Asteraceae) endemic to the coastal sand dunes of south‐west France

Endemic plants inhabiting coastal sand dunes show augmented extinction risks due to the dynamic nature of dunes and strong human pressure on coastal areas. To investigate the survival strategies and threats to long‐term survival of such species, we combined genetic, morphological and biogeographical approaches, using the example of Hieracium eriophorum (Asteraceae) and its putative cryptic sister species H. prostratum, which are endemic to the longest coastal sand dune in Europe. An analysis of amplified fragment length polymorphism revealed high within‐population genetic variability, and slight isolation by distance was the only indication of genetic population structure. Thus, no signs of genetic threats to survival were found. Furthermore, genetic and morphometric data provided no evidence for the existence of two species. Therefore, we propose to synonymize H. prostratum with H. eriophorum and provide a nomenclatural overview with typification. Finally, an analysis of historical distribution records showed that, during the last 100 years, the species was lost from its range margins, where its habitat became fragmented. Taken together, our results suggest that one successful survival strategy of narrow endemics may be the achievement of large local population sizes on a small geographical scale, thus avoiding the genetic problems inherent to small and fragmented populations. Dune management policies should thus take care that the current tendencies to allow more erosion will not result in too severe fragmentation of the remaining continuous stretches of dune habitat. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 169 , 365–377.     

Responses of Shrub Midstory and Herbaceous Layers to Managed Grazing and Fire in a North American Savanna (Oak Woodland) and Prairie Landscape

Worldwide, savanna remnants are losing acreage due to species replacement with shade-tolerant midstory forest species as a response to decades of fire suppression. Because canopy closes grasses and other easily ignitable fuels decline, therefore, fire, when reintroduced after years of absence, is not always effective at restoring the open structure original to these communities. Our study sought to determine if managed grazing is an alternative tool for reducing shrub densities and restoring savanna structure without the impacts on soils and native vegetation observed with unmanaged grazing. We compared effects of fire and managed grazing on shrub and herb composition within degraded oak savanna and tallgrass prairie of the U.S. Upper Midwest using a randomized complete block design. The vegetation response to treatments differed by species and by vegetation type. Total shrub stem densities declined 44% in grazed and 68% in burned paddocks within savanna and by 33% for both treatments within prairie. Within savanna, cattle reduced stem densities of Rubus spp. 97%, whereas fire reduced Ribes missouriense stems 96%. Both fire and grazing were effective at reducing stem numbers for several other shrub species but not to the same degree. Native forbs were suppressed in grazed savanna paddocks, as were native grasses in grazed prairie paddocks along with a minor increase of exotic forbs. We did not observe changes in soil bulk density. We conclude that managed grazing can serve as a valuable supplement but not as a replacement to fire for controlling shrubs in these systems.     

Two New Brackish Ciliates,Amphileptus spiculatus sp. n. and A. bellus sp. n. from Mangrove Wetlands in Southern China,with Notes on the Molecular Phylogeny of the Family Amphileptidae (Protozoa,Ciliophora, Pleurostomatida)

Two new brackish pleurostomatid ciliates, Amphileptus spiculatus sp. n. and A. bellus sp. n. were collected from mangrove wetlands of southern China and their morphology and molecular phylogeny were studied. Amphileptus spiculatus sp. n. can be distinguished from congeners by the presence of 11–14 right and 6–8 left kineties, two macronuclear nodules and a conspicuous beak‐like anterior body end. Amphileptus bellus sp. n. is characterized by the presence of 2–4 macronuclear nodules, 31–35 right and 6 or 7 left kineties and two types of extrusomes. Phylogenetic analyses based on SSU rDNA sequences data indicate that the family Amphileptidae is paraphyletic.     

Differential antioxidative responses of ascorbate-glutathione cycle enzymes and metabolites to chromium stress in green gram (Vigna radiata L. wilczek) leaves

Chromium-induced antioxidative responses of ascorbate-glutathione cycle enzymes and metabolites in green gram(Vigna radiata L. Wilczek) leaves were investigated in both dose and time-dependent manners. Rapid uptake of Cr was observed immediately after the start of treatment. Significant reduction was observed in leaf biomass under 300 μM Cr-treatment. Treatment with 300 μM Cr increases the content of hydrogen peroxide and Superoxide dismytase activity upto initial 96 h, and then gradually declined to the basal level. Ascorbate peroxidase and guaiacol peroxidase activities were low in 300 μM Cr-treated leaves during the first 96 h, but significantly increased therefore, suggesting that increased enzyme activities would be responsible for the removal of H₂O₂. Catalase activities were always suppressed under Cr stress. Contents of reduced ascorbate and dehydroascorbate were significantly decreased under 300 uM Cr-treatment. The reduced glutathione content decreased at early stages of Cr-treatment. However, it was restored to the normal level as in controls thereafter. In contrast, the glutathione disulphide content showed a progressive increase during the initial hours of Cr-treatment. The non-protein thiol content was shown to increase during the first several hours, but it declines at later stages. The present results demonstrate that Cr-induced oxidative stress is an important component of the plant’s reaction to toxic levels of Cr.     

Responses of Mediterranean Plant Species to different fire frequencies in Garraf Natural Park (Catalonia,Spain): field observations and modelling predictions.

Dynamics of the coexisting Mediterranean species Pinus halepensis, Quercus coccifera, Erica multiflora, Rosmarinus officinalis, Cistus albidus, C. salviifolius and Ampelodesmos mauritanica, with contrasted life history traits have been studied under different fire scenarios, following two approaches: a) field survey in areas with three different fire histories (unburned for the last 31 years, once burned in 1982, and twice burned in 1982 and 1994), and b) simulations with different fire recurrence using the FATE vegetation model. We compared observed abundance in the field survey to simulation outputs obtained from fire scenarios that mimicked field fire histories. Substantial mismatching did not occur between field survey and simulations. Higher fire recurrences were associated with an increase in the resprouting Ampelodesmos grass, together with a decrease in Pinus abundance. Resprouting shrubs did not show contrasting changes, but trends of increase in Quercus and decrease in Erica were observed. The seeders Rosmarinus and Cistus achieved maximum abundance at intermediate fire recurrence. We also performed ten 200 year simulations of increasing fire recurrence with average times between fires of 100, 40, 20, 10, and 5 years. A scenario without fire was also simulated. High fire recurrence produces an increase in Ampelodesmos, a grass which is becoming dominant in the area, and a small increase in Erica, but Quercus abundance decreases and Pinus disappears. Rosmarinus and Cistus abundance peaks at intermediate fire frequencies. When comparing these simulations to those in which Ampelodesmos was excluded, we found that the absence of the grass only increased Cistus occurrence in the community, this effect being more important at frequent fire recurrence. The study suggests that simple models based on life history traits may be useful in interpreting plant community dynamics in Mediterranean ecosystems that are greatly influenced by differences in the fire regime.