基于生态系统服务功能和生态敏感性的生态空间划定研究: 以南宁市为例

探究滇池流域近30年间生态敏感性时空演变特征。

定量分析生态因子的相互关系,基于1995年、2005年、2010年和2018年的遥感影像和基础数据,运用CA-MC模型、重心迁移及核密度进行分析。

1995—2018年,滇池流域土地覆盖/利用、河岸缓冲区和景观指数敏感性均呈波动下降趋势,归一化植被指数敏感性总体升高,流域综合生态敏感性呈现高等级向低等级转化的特征。不敏感、轻度敏感和中度敏感性区域面积整体上升,分别增加2.10%、0.47%和11.20%;高度敏感性区域面积波动下降,减少13.77%。各级生态敏感性重心转移及核密度分布差异显著,不敏感和轻度敏感性区域向西北方向迁移,中度敏感和极度敏感性区域向西南方向迁移,高度敏感性区域向东南方向迁移。通过CA-MC模型推演,2018—2026年滇池流域敏感性空间演变,总体敏感性等级缓慢上升。

研究区域生态敏感性演变过程能够及时了解区域生态演变规律,提出生态保护策略。

     

青海湖湖盆南部的高寒灌丛

本文对青海湖湖盆南部的高寒灌丛类型及动态进行了初步探讨。研究地区高寒灌丛主要有以下五类：金露梅灌丛、金露梅＋山生柳灌丛、山生柳＋金露梅＋鬼箭锦鸡儿灌丛、山生柳灌丛和鬼箭锦鸡儿灌丛。分析表明，气候和地形条件是影响本区高寒灌丛动态的主要因素。     

Effects of land use changes on winter-active Collembola in Sanjiang Plain of China

Sanjiang Plain is the largest concentrated area of freshwater wetlands in China, however nearly 80% of these freshwater wetlands were drained or reclaimed in the past 50 years. It is important to know whether wetlands reclamation would affect soil invertebrates, especially the winter-active invertebrates. During November 2011 to April 2012, we used pitfall traps and in-field direct observation methods to study the activity of collembolans in wetland, and a reclaimed forest plantation and soybean field. In total, 3465 collembolans were captured and identified to 8 species from 6 families. Desoria sp. 1, Desoria sp. 2 and Desoria sp. 3 were the three dominant species. Collembolan abundance and assemblages were significantly affected by the land use changes. The results showed that (1) Collembola captured by pitfall traps showed a highest abundance in wetland, with ∼50% decreased abundance in soybean field, and ∼75% decreased in the forest plantation. (2) Collembola activity changed during the winter season, their activity significantly increased from early winter to late winter; with a peak in March in all three land use types. (3) Collembola assemblages were affected by land use changes with a significant decrease of frequency of Desoria sp. 3 and a significant increase of frequency of Desoria sp. 2 in soybean field and forest plantation. (4) Collembolan densities on the snow surface usually peaked between 1400 h and 1500 h, and decreased quickly when the temperature dropped below freezing. Mean abundance reached 119 individuals m⁻² on the snow surface in wetland, 152 individuals m⁻² in soybean field, and 64 individuals m⁻² in forest plantation. All collembolans moved up and down through the snow profile depending on temperature, no collembolans were found on the snow surface in the evening. Our study indicated that the reclamation of wetland resulted in a significant decrease of abundance and a different assemblage of winter active Collembola in Northeast China, but land use changes did not change their pattern of activity: Collembolans were rarely active in early and middle winter and mostly active in late winter. Their daily densities on the snow surface fluctuated according to both air temperatures and land use types.     

巴塞罗那城市公园发展更新与特征研究

巴塞罗那城市规划与空间更新作为世界典范,其城市公园更新与发展历程也值得学习与借鉴.结合对巴塞罗那城市更新计划与政策背景的分析,梳理与分析了巴塞罗那城市公园发展的历史进程,将其分为3个主要阶段:注重将自然引入城市的萌芽期(19世纪50年代—20世纪70年代);寻求人与自然和谐的发展期(20世纪80—90年代);思考人、自...     

Precautionary rules for exotic trout aquaculture in fishless shallow lakes of Patagonia: minimizing impacts on the threatened hooded grebe (Podiceps gallardoi)

• 1. Conflicts between habitat use and conservation are inherent to the management of wetlands. A major challenge for their management is to preserve habitat while addressing the demands from multiple users. In southern Patagonia (Argentina), a growing aquaculture activity based on rainbow trout introductions in shallow lakes is generating concerns about the effects on the waterbird fauna, including some endemic species.
• 2. Generalized linear models (GLM) were used to analyse data on the endemic hooded grebe (Podiceps gallardoi) collected over a diverse set of lakes to: (1) build presence‐absence models as a function of environmental variables; (2) assess current and potential overlap with trout aquaculture; (3) explore the power of alternative lake assignment algorithms based on habitat variables to segregate critical habitat and aquaculture activities; and (4) explore the correlation between the probability of grebe presence and their abundance in given lakes.
• 3. Hooded grebe presence is clearly correlated with macrophyte cover, lake area, and water conductivity. Medium size lakes, with a combination of emerging macrophytes, adjacent to open water areas had the highest probability of both hooded grebe presence and abundance.
• 4. Different lake allocation scenarios are identified that could grant significant protection to hooded grebes without substantial losses for trout producers. The a priori probability to hold hooded grebe, assigned by the model based on lake characteristics, provides a tool that can be used by managing authorities to derive precautionary management rules to regulate aquaculture and to preserve primary hooded grebe habitat. Copyright © 2009 John Wiley & Sons, Ltd.

     

Summer habitat use and feeding of juvenile Arctic charr,Salvelinus alpinus,in the Canadian High Arctic

Abstract – Owing to limited knowledge of the habitat use and diet of juvenile Arctic charr from the High Arctic, particularly young‐of‐the‐year (YOY), we assembled data obtained from samples taken in and around Lake Hazen, Nunavut, Canada, to assess juvenile habitat use and feeding. Juvenile charr demonstrated a preference for stream environments, particularly those fed by warm upstream ponds. Charr occupying both stream and nearshore lake habitats were found to feed similarly, with chironomids occurring most frequently in diets. Some older stream‐dwelling charr preyed on smaller, younger Arctic charr. Preferred stream occupancy is likely mediated by physical barriers created mainly by water velocity, and by distance from the lake, lake‐ice dynamics, low water depth, and turbidity. Water velocities resulted in stream habitat segregation by size, with YOY mainly found in low‐velocity pools and back eddies adjacent to stream banks, but not in water velocities >0.1 m·s^?1. Greatest charr densities in streams were found in small, shallow, slow‐flowing side channels, which are highly susceptible to drought. Under predicted climate change scenarios, streams fed by small ponds will be susceptible to intermittent flow conditions, which could result in increased competition among juvenile charr for the remaining stream habitats. In addition, glacier‐fed streams are likely to experience increased flow conditions that will exacerbate physical barriers created by water velocity and further reduce the availability of preferred stream habitat.     

鄱阳湖生态经济区高效生态农业的发展

《鄱阳湖生态经济区规划》于2009年12月12日获国务院正式批复,标志着建设鄱阳湖生态经济区上升为国家战略。发展高效生态农业是建设鄱阳湖生态经济区的重要内容和目标。本文在简述高效生态农业概念与特征的基础上,首先对鄱阳湖生态经济区发展高效生态农业的重要意义进行了简要分析;接着,重点对鄱阳湖生态经济区高效生态农业的类型、模式和技术进行了比较全面的论述;最后,提出了鄱阳湖生态经济区高效生态农业进一步发展的对策和措施。该文对当前正在从事鄱阳湖生态经济区建设的领导干部、科技工作者和普通群众均具有参考价值。     

湿地生态系统碳储量与碳循环研究

湿地生态系统是地球主要生态系统之一,其有机碳储量及碳循环是全球碳循环研究的重要基础,也是全球气候变化研究的重要内容之一。研究表明,湿地保护和恢复能促进碳积累和减少温室气体排放。笔者探讨了湿地生态系统碳储量、碳平衡和温室气体排放的影响、湿地与全球气候变化关系等方面的问题,并对洞庭湖湿地碳循环研究做了展望。