广西北海中国鲎资源现状以及保育工作进展

中国鲎种群数量近年来急剧下降,资源面临枯竭.位于北部湾的广西北海作为中国鲎理想栖息地,是我国中国鲎的主要产地,因此在北海开展中国鲎的保育工作尤为重要.本文调查分析了广西北海地区中国鲎幼体集聚地西背岭潮间带(21°24′30″N-21°25′24″N及109°11′12″E-109°13′14″E)中国鲎幼体分布现状以及...     

淀山湖浮游动物群落时空分布特征及其与环境因子的关系

淀山湖是上海市最大的淡水湖泊,属亚热带浅水湖泊.于2017年对该湖的浮游动物和水质参数进行逐月调查,并结合浮游植物群落数据,采用多元回归树模型(multivariate regression trees,MRT)和主坐标分析(principal coordinates analysis,PCo A)等方法研究了该湖浮游动物群落结构时空分布特征及其与环境因子的关系.结果表明,淀山湖浮游动物群落结构季节差异显著(P 0. 05),但仅在春、夏季节存在空间差异(P 0. 05),其他季节空间差异不显著(P 0. 05).水温、叶绿素a、氨氮以及蓝藻丰度是引起淀山湖浮游动物群落时空变化的关键性因子. MRT分析表明,当水温13. 07℃时,表现为冬季群落特征,当水温在13. 07～19. 57℃之间时,表现为春季群落特征;当水温≥19. 57℃时,叶绿素a浓度≥9. 03μg·L-1,则为夏季群落特征,而当叶绿素a浓度9. 03μg·L-1时,则表现为秋季群落特征.聚类分析将淀山湖浮游动物群落分成3个空间区域;春季时,当氨氮浓度1. 11 mg·L-1时,上游进水区(区域Ⅱ)浮游动物群落与其他两个区域有显著差异(P 0. 05);而夏季当蓝藻生物量≥2. 58 mg·L-1时,区域Ⅰ的浮游动物群落与其他两个区域有显著的空间差异(P 0. 05).     

基于PLUS-InVEST模型的哈尔滨市土地利用及生境质量预测

分析城市土地利用与生境质量时空演变,能够揭示土地利用和生境质量的关联性,有助于城市土地政策合理决策和生态环境高质量发展.研究基于土地利用转移矩阵和IM模型分析哈尔滨市2000~2020年土地利用的变化,并结合PLUS模型进行各用地类型扩张因子的驱动探究以及2030年自然发展情景、生态保护情景、耕地保护情景和城镇发展情景下的土地利用预测,最后利用InVEST模型完成生境质量分析.结果表明：①哈尔滨市土地利用类型以耕地、林地和草地为主,2000~2020年期间,草地、耕地、林地和人造地表转入面积较多,土地利用强度变化倾向性特征明显;水体、裸地和湿地类型的转入较少,多呈现抑制性特征. ②高程是影响草地、耕地、林地、裸地、湿地和水体扩张的主要因子;影响人造地表扩张的主要因子是社会经济因素. ③模拟哈尔滨市2030年4种情景下各土地利用类型面积,其中林地面积均增加,草地面积均减少,湿地、水体和裸地面积变化均不显著;除生态保护情景外,人造地表面积均增加,耕地面积均减少. ④2000~2020年间,哈尔滨市生境质量整体提高. ⑤2030年哈尔滨市4种情景下生境质量空间格局演变规律整体保持一致,生境质量均呈现变好趋势,其中生态保护情景下低、中等生境质量面积减少,而较高、高生境质量面积有所增加,生境质量提升相对明显.研究结果可为哈尔滨市生态文明发展以及城市规划建设提供一定的科学依据及思路.     

基于参数最优地理探测器的福州市生境质量时空格局与驱动力分析

揭示生境质量的时空演变特征和影响因素可为区域可持续发展提供参考依据。基于2000年、2010年和2020年的土地利用数据,运用InVEST模型、土地利用转移矩阵和参数最优地理探测器等方法,综合分析福州市生境质量时空演变及其驱动因素。结果表明：福州市2000年、2010年和2020年生境质量指数分别为0.812、0.806和0.793,生境质量改善的面积小于生境质量退化的面积,福州主城区和东南沿海区域的生境状况亟须改善。3 km网格为本研究的最佳空间尺度,最佳数据离散化分类数为6,自然间断点法更能解释驱动因素的驱动程度。高程、坡度和夜间灯光是福州市生境质量空间分异的主要影响因素,坡度和夜间灯光的交互作用对生境质量变化的解释力最强。

     

FROM FLOW TO FISH TO DOLLARS: AN INTEGRATED APPROACH TO WATER ALLOCATION1

This paper details a case study of economic and natural system responses to alternative water management policies in the Cache La Poudre River basin, Colorado, 1980–1994. The case study is presented to highlight the value and application of a conceptual integration of economic, salmonid population, physical habitat, and water allocation models. Five alternative regimes, all intended to increase low winter flows, were investigated. Habitat enhancements created by alternative regimes were translated to population responses and economic benefits. Analysis concluded that instream flows cannot compete on the northern Colorado water rental market; cooperative agreements offer an economically feasible way to enhance instream flows; and establishing an instream flow program on the Cache La Poudre River mainstem is a potentially profitable opportunity. The alliance of models is a dynamic multidisciplinary tool for use in professional settings and offers valuable insight for decision-making processes involved in water management.     

Use of carrion fly iDNA metabarcoding to monitor invasive and native mammals

Severely fragmented habitats increase the risk of extirpation of native mammal populations through isolation, increased edge effects, and predation. Therefore, monitoring the movement of mammal populations through anthropogenically altered landscapes can inform conservation. We used metabarcoding of invertebrate-derived DNA (iDNA) from carrion flies (Calliphoridae and Sarcophagidae) to track mammal populations in the wheat belt of southwestern Australia, where widespread clearing for agriculture has removed most of the native perennial vegetation and replaced it with an agricultural system. We investigated whether the localization of the iDNA signal reflected the predicted distribution of 4 native species—echidna (Tachyglossus aculeatus), numbat (Myrmecobius fasciatus), woylie (Bettongia penicillata), and chuditch (Dasyurus geoffroii)—and 2 non-native, invasive mammal species—fox (Vulpes vulpes) and feral cat (Felis catus). We collected bulk iDNA samples (n = 150 samples from 3428 carrion flies) at 3 time points from 3 conservation reserves and 35 road edges between them. We detected 14 of the 40 mammal species known from the region, including our target species. Most detections of target taxa were in conservation reserves. There were a few detections from road edges. We detected foxes and feral cats throughout the study area, including all conservation reserves. There was a significant difference between the diversity (F_3, 98 = 5.91, p < 0.001) and composition (F_3, 43 = 1.72, p < 0.01) of taxa detections on road edges and conservation reserves. Conservation reserves hosted more native biodiversity than road edges. Our results suggest that the signals from iDNA reflect the known distribution of target mammals in this region. The development of iDNA methods shows promise for future noninvasive monitoring of mammals. With further development, iDNA metabarcoding could inform decision-making related to conservation of endangered taxa, invasive species management, and impacts of habitat fragmentation.     

Bird Species' Tolerance of Secondary Forest Habitats and Its Effects on Extinction

Abstract:  Intense deforestation causes massive species losses. These losses occur because the habitats supplanting primary forest are inadequate to sustain viable populations of forest-dependent species. Despite this, certain species do seem to persist within the secondary habitats that replace original forest. This implies that there is a special class of species that might survive the loss of primary forest. Such a result would significantly influence conservation plans and extinction predictions. We tested whether species that tolerate secondary habitats survive extensive habitat loss and whether the same degree of loss threatens species that are forest obligates. To identify purported "survivors," we compared the remaining range sizes of endemic birds, their abundances, and their degree of extinction threat. We did this within the remaining Atlantic Forest of Brazil, a region extremely rich in endemics but with only approximately 10% of its forest remaining. We found no survivors. Habitat loss threatens forest-obligate birds and those using secondary habitats equally.     

Predicting Future Threats to the Native Vegetation of Robinson Crusoe Island, Juan Fernandez Archipelago, Chile

Abstract:   The Juan Fernandez Archipelago, a Chilean national park and biosphere reserve, is 700 km west of continental Chile. Invasive plant species pose major threats to the native, highly endemic vegetation, especially on Robinson Crusoe Island (Mas a Tierra), where there is a permanent settlement. We used historical and recent vegetation map data as well as recent vegetational point data to reconstruct vegetational changes on the island since the early twentieth century. In addition, we used logistic regression models with environmental variables or their surrogates (elevation, solar radiation, topographic similarity index, slope position) to estimate the potential distributions of the worst invaders. Native vegetation has been affected most severely by Acaena argentea , Aristotelia chilensis , Rubus ulmifolius , and Ugni molinae , leading to a significant decrease of endemic plants in the montane forests and native shrublands. The native forest has decreased by approximately one-third. The area affected by Aristotelia chilensis increased from 6.5% to 14% of the total island area. Ugni molinae , once rare, is now abundant (4.6%), as is Acaena (11.9%). Rubus ulmifolius , not present 80 years ago, now covers about 7% of the island's surface. The distributions of all studied species except Rubus ulmifolius are significantly ( p < 0.05) controlled by the environmental factors we examined. Inferring from potential distributions of Aristotelia chilensis and Ugni molinae , 50% of the native montane forest could be invaded or replaced (with a probability of >60%) by these plants. Based on the invasion speed of the past 80 years, this would take another 80 years if conservation measures do not succeed.     

On the Biology of Five-toed Pigmy Jerboa (Cardiocranius paradoxus Satunin, 1902) in the Ubsu-Nuur Depression

Russian Journal of Ecology -     

Integrated assessment of river health based on the conditions of water quality,aquatic life and physical habitat

The health conditions of Liao River were assessed using 25 sampling sites in April 2005, with water quality index, biotic index and physical habitat quality index.Based on the method of cluster analysis (CA) for water quality indices, it reveals that heavily polluted sites of Liao River are located at estuary and mainstream.The aquatic species surveyed were attached algae and benthic invertebrates.The result shows that the diversity and biomass of attached algae and benthic index of biotic integrity (B-IBI) are degrading as the chemical and physical quality of water bodies deteriorating.Physiochemical parameters, BOD5, CODCr, TN, TP, NH3-N, DO, petroleum hydrocarbon and conductivity, were statistically analyzed with principal component analysis and correlation analysis.The statistical results were incorporated into the integrated assessing water quality index, combining fecal coliform count, attached algae diversity, B-IBI and physical habitat quality score, a comprehensive integrated assessing system of river ecological health was established.Based on the systimetic assesment, the assessed sites are categorized into 9 "healthy" and "sub-healthy" sites and 8 "sub-sick" and "sick" sites.