Disturbances caused by livestock grazing are considered as a key attributable factor for the habitat loss of red panda. The present study was carried out in Eastern Nepal mainly focusing on the habitat preferences of ...Disturbances caused by livestock grazing are considered as a key attributable factor for the habitat loss of red panda. The present study was carried out in Eastern Nepal mainly focusing on the habitat preferences of red panda and impacts of livestock grazing on it. In total, 15 linear transects were delineated at an elevation interval of 100 m assessing indirect signs of red panda and livestock. Habitat preferences of red panda, vegetation abundance, coverage percentage of vegetation layers (canopy and shrub layer) and distance to water source were recorded using randomly plotted 58 quadrats of 10 m × 10 m. Questionnaire survey and Key Informant Interviews were carried out to evaluate the perception of local community on conservation threats and importance of red panda conservation. Jaccard’s similarity index was used to determine the spatial habitat overlap of livestock and red panda. Litsea elongata, Lithocarpus pachyphylla and Rhododendron falconeri were the most common species in the study area. Grazing signs were observed from 51% of red panda habitats in the study area. Livestock herding has induced negative impacts on the habitat of red panda inside the community forests. The study findings will extend the existing body of knowledge regarding the status of red panda in Eastern Himalayas. In addition, this research will help in the formulation of effective legal and strategic framework of sustainable grazing management.展开更多
The hard tissues of squid can provide important information for species identification. In this study, we used statolith and beak to identify three squid species including Uroteuthis duvaucelii, Loliolus beka, and U. ...The hard tissues of squid can provide important information for species identification. In this study, we used statolith and beak to identify three squid species including Uroteuthis duvaucelii, Loliolus beka, and U. edulis in the South China Sea. Because of the highly overlapping habitat and similar body morphology of the three squid species, we explored four different ways to identify them, by using statolith, upper beak, lower beak and a combination of statolith and beak. An outline geometric morphometric method and stepwise discriminant analysis were used to evaluate the most suitable method for the identification. We found that the combination of statolith and beak had the highest cross validation rate that was 75.0%, 87.5% and 88.7% for U. duvaucelii, L. beka and U. edulis, respectively. Using two beaks had similar results and the lowest cross validation rate was 60.0%, 50.0%, and 73.7% for the upper beak, 46.9%, 58.5% and 75.3% for the lower beak of U. duvaucelii, L. beka and U. edulis, respectively. Analyzing with the statolith had moderate cross validation which was 72.2%, 80.0%, and 87.7% for U. duvaucelii, L. beka and U. edulis, respectively. From the results it is suggested when the entire body of a squid is available, a combination of statolith and beak should be used for the identification. When only one hard tissue is available, species identification can be subjected to large errors.展开更多
文摘Disturbances caused by livestock grazing are considered as a key attributable factor for the habitat loss of red panda. The present study was carried out in Eastern Nepal mainly focusing on the habitat preferences of red panda and impacts of livestock grazing on it. In total, 15 linear transects were delineated at an elevation interval of 100 m assessing indirect signs of red panda and livestock. Habitat preferences of red panda, vegetation abundance, coverage percentage of vegetation layers (canopy and shrub layer) and distance to water source were recorded using randomly plotted 58 quadrats of 10 m × 10 m. Questionnaire survey and Key Informant Interviews were carried out to evaluate the perception of local community on conservation threats and importance of red panda conservation. Jaccard’s similarity index was used to determine the spatial habitat overlap of livestock and red panda. Litsea elongata, Lithocarpus pachyphylla and Rhododendron falconeri were the most common species in the study area. Grazing signs were observed from 51% of red panda habitats in the study area. Livestock herding has induced negative impacts on the habitat of red panda inside the community forests. The study findings will extend the existing body of knowledge regarding the status of red panda in Eastern Himalayas. In addition, this research will help in the formulation of effective legal and strategic framework of sustainable grazing management.
文摘植物多样性与植物竞争强度和生态位重叠度的关系会随环境发生变化。为探究上述关系在若尔盖地区的表现形式,于2021年8月对若尔盖地区典型的水生、湿生、湿生—中生和中生植物群落进行调查,构建了新的植物竞争强度(Competition intensity,CI)公式并进行测算,计算了植物群落的植物多样性指数(包括物种丰富度、Shannon⁃Weiner指数、Simpson指数和Pielou均匀度指数)和生态位重叠度(Niche overlap of species,NOS),分析了植物群落物种多样性指数与CI和NOS的关系。结果表明:1)从水生到中生生境,植物多样性指数均呈增加趋势(P<0.05);2)湿生—中生生境的CI显著高于湿生生境(P<0.05),湿生生境的NOS高于水生生境(P<0.05);CI与NOS无显著相关性,但在湿生生境中两者呈倒抛物线关系(P<0.05)。3)整体来看,植物群落的物种丰富度与CI呈抛物线关系(P<0.05),与NOS无显著关系(P>0.05);Shannon⁃Weiner指数、Simpson指数和Pielou均匀度指数均与NOS呈线性正相关(P<0.05),与CI无显著关系(P>0.05);从单个生境看,湿生—中生生境的Simpson指数、Shannon⁃Weiner指数和Pielou均匀度指数与CI呈线性负相关(P<0.05),其余生境的上述多样性指数与CI无显著关系(P>0.05);各生境的植物多样性指数均与NOS无显著相关性(P>0.05)。本研究表明,从水生到中生生境,若尔盖地区的植物多样性呈增加趋势,但植物多样性与物种竞争强度和生态位重叠度的关系较复杂。本研究结果有助于理解若尔盖高原植物多样性的形成机制。
基金the National Natural Science Foundation of China (No. NSFC41476129)the Shanghai Leading Academic Discipline Project (Fisheries Discipline)supported by Shanghai Ocean University International Center for Marine Studies and Shanghai 1000 Talents Program
文摘The hard tissues of squid can provide important information for species identification. In this study, we used statolith and beak to identify three squid species including Uroteuthis duvaucelii, Loliolus beka, and U. edulis in the South China Sea. Because of the highly overlapping habitat and similar body morphology of the three squid species, we explored four different ways to identify them, by using statolith, upper beak, lower beak and a combination of statolith and beak. An outline geometric morphometric method and stepwise discriminant analysis were used to evaluate the most suitable method for the identification. We found that the combination of statolith and beak had the highest cross validation rate that was 75.0%, 87.5% and 88.7% for U. duvaucelii, L. beka and U. edulis, respectively. Using two beaks had similar results and the lowest cross validation rate was 60.0%, 50.0%, and 73.7% for the upper beak, 46.9%, 58.5% and 75.3% for the lower beak of U. duvaucelii, L. beka and U. edulis, respectively. Analyzing with the statolith had moderate cross validation which was 72.2%, 80.0%, and 87.7% for U. duvaucelii, L. beka and U. edulis, respectively. From the results it is suggested when the entire body of a squid is available, a combination of statolith and beak should be used for the identification. When only one hard tissue is available, species identification can be subjected to large errors.
