Species Composition of Freshwater Invertebrates in Relation to Chemical and Physical Factors in High Mountains in Soutwestern Norway

The composition of benthic invertebrates was investigated in three Norwegian alpine watersheds during the period 1991–1997. The watersheds represented an environmental gradient in chemical factors. The Kvenna watershed was relatively well buffered, Lake Øvre Neådalsvatn was poorly buffered, but receives low inputs of atmospheric pollution while Lake Stavsvatn has low buffering capacity and receives larger inputs of acidifying components. Qualitative samples were taken in the inlet rivers, lake littoral zone, lake outlet and in the outlet rivers of the lakes for analyses of species composition. In Ø. Neådalsvatn the water chemical data showed strong seasonal variations with waters of low ionic content during snowmelt and summer, while increased ion concentrations build up during winter. The time of ice break and/or water temperature rise during the growing season affected the life cycle of Siphlonurus lacustris and Parameletus chelifer. Even small changes in pH or ANC seemed to have a strong effect on Baetis rhodani. In the Kvenna watershed eight very sensitive species were found at sites with pH 6.5, Ca 1.2 mg L^-1 and LAl < 10 eq L^-1. Only two highly sensitive species, B. rhodani and Capnia sp. were recorded when pH was 6, concentration of calcium 0.8 mg L^-1 and low labile aluminium < 10 eq L^-1. None of the highly sensitive species occurred in Stavsvatn, a formerly acidified area, where LAl concentrations ranged between 25–40 eq L^-1. Low ionic content and elevated concentrations of labile aluminium are suggested to exclude sensitive invertebrates in alpine lakes. Synergistic effects of dilute water and harsh climate are assumed to increase sensitivity of invertebrates to acid water. Global warming will result in higher precipitation and more snow in the west Norwegian alpine area. This will shorten the growing season, increase the amount of dilute water and consequently threaten invertebrate species living close to their tolerance limits.     

Is Shennongjia a Suitable Site for Reintroducing Giant Panda: An Appraisal on Food Supply

The giant panda was found on Mount Shennongjia in Central China for thousands of years but vanished in the late 19th century. The possibility for reintroducing the giant panda in Shennongjia is discussed in terms of food availability, carrying capacity, and predicted bamboo flowering. Three species (Fargesia spathacea, F. murielae, and Yushania confusa) are considered the preferred forage bamboos, which could feed 193–223 giant pandas. However, in 1879–1888 these three species synchronously flowered and died back. In the past, such bamboo flowering usually forced the panda to migrate to a new habitat where forage bamboos were available. But since the 19th century, Shennongjia has become separated from other panda habitats by densely populated agricultural zones. Multi-species flowering of the forage bamboo and isolating of the habitat might caused the extinct of the giant panda in Shennongjia. If the flowering cycle of the bamboo is genetically fixed, the next synchronous flowering of two staple food species (F. spathacea and F. murielae) may occur in 2436–2439. It means that the food supply is dependable in Shennongjia for reintroducing the giant panda before 2436.     

赤水市山地农业气候资源与果树生产布局

本文分析了赤水市山地丘陵气候的垂直变化规律，根据各气侯观测资料和温度垂直分布模型，推算出不同海拔高度各温度要素值。根据热量条件指标的自然分异和果树分布的实际情况，划分出不同农业气候层的高度，并对主要果树在赤水地区种植的适宜高度进行了气候适宜性分析，提出了不同农业气候层次的果树发展方向。     

安徽省大别山区复合农林业的诊断与设计

长江贯穿安徽省南部，流经面积６６０３１ｋｍ＾２，占全省面积４７％，大别山在安徽内地处西南边境，占地１２７００ｋｍ＾２，其水系分属几个不同支流后最终注入长江。通过对安徽省大别山区农村的实地调查，分析了该地区的自然条件和社会经济要素及贫困原因，提出了复合农林业在该地区的应用前景与方式。     

山岳型旅游地旅游城镇化动力机制研究——以九华山为例

旅游城镇化是指发展旅游业的地区为了给旅游者提供交通、游览、食宿、娱乐、购物等一系列服务，使生产、提供这些商品和服务的行业与居民大量在此聚集，逐渐形成具有明显职能特色的城镇的过程。分析旅游城镇化现象产生的动力机制是旅游城镇化研究的重要内容。在实地调研的基础上，以九华山为例，分析了山岳型旅游地旅游城镇化现象产生和发展的内外多维动力系统，并结合九华山独特的佛教旅游地特征，有针对性地分析了九华山旅游城镇化发展的特点。     

山东枣庄熊耳山崩塌遗迹成因初探

通过实地考察和分析,结合历史地震记载资料,对熊耳山地貌、裂谷以及崩塌遗迹的形成原因进行了初步探讨。初步认为,熊耳山裂谷及崩塌是1668年郯城81/2级地震的产物,属典型的地震灾害遗迹。     

低山丘陵区农业景观格局对害虫-捕食性天敌食物网的影响

农业集约化导致景观破碎化、均质化程度加深.景观斑块的组成及合理布局带来的农业景观高异质性是维持区域生物多样性的关键.该文选择具有典型低山丘陵地貌的辽宁省建平县为研究区,在食物网水平上探究区域农业景观格局对生物多样性的影响.选取20个样区,在明晰区域景观特征、分析害虫-捕食性天敌食物网结构的基础上,采用回归分析和最优模型...     

防灾视角下基于MCR模型的山地生态安全格局优化研究——以京津冀山区为例

区域生态安全格局的优化对改善区域自然生态系统服务功能、减轻区域典型灾害负面影响等有重要作用。该文以京津冀山区为研究对象,在区域山洪灾害背景下运用灾害学、景观生态学等理论,将最小累积阻力模型(MCR)引入山区生态安全格局的构建过程。通过借助GIS技术平台分析了研究区基于MCR模型建立的生态网络,构建了由斑块、生态廊道、基质镶嵌的区域生态化网络格局。针对分析结果,重点从城乡规划视角提出生态安全格局优化的措施,主要包括生态约束条件下生态网络结构优化和区域尺度的山区生态修复,以期为维持山区生态安全、国土综合整治以及实现京津冀区域协同发展提供科学依据。     

粤北山区近25年来耕地表层土壤有机碳变化分析

以粤北山区典型区的连州市为例,利用第二次土壤普查资料和2007年耕地地力调查样点分析结果,对研究区耕地表层(0~20 cm)土壤有机碳质量分数和有机碳密度的变化特征进行了分析。结果表明:25年以来,连州市耕地表层有机碳质量分数和密度有所增加,分别从1982年的16.3 g·kg-1、40.88 t·hm-2上升到2007年的17.37 g·kg-1、43.31 t·hm-2。土壤有机碳随土壤类型的不同而变化复杂,土壤有机碳呈上升趋势的有潴育型水稻土、淹育型水稻土、渗育型水稻土,而沼泽型水稻土、潜育型水稻土和矿毒田呈下降趋势,主要旱地土壤类型(黄壤、红壤、红色石灰土、酸性紫色土)表层土壤有机碳质量分数呈上升趋势。从土地利用类型综合考量,水田、旱地表层土壤有机碳质量分数和密度都呈上升趋势,其中水田的有机碳质量分数和密度分别由80年代初期的18.30 g·kg-1、44.80 t·hm-2上升到2007年的18.78 g·kg-1、46.21 t·hm-2;旱地的有机碳质量分数和密度分别由80年代初期的10.46 g·kg-1、29.27 t·hm-2上升到2007年的13.17 g·kg-1、34.67 t·hm...     

粤北山区近25年来耕地表层土壤有机碳变化分析

以粤北山区典型区的连州市为例,利用第二次土壤普查资料和2007年耕地地力调查样点分析结果,对研究区耕地表层（0~20 cm）土壤有机碳质量分数和有机碳密度的变化特征进行了分析。结果表明：25年以来,连州市耕地表层有机碳质量分数和密度有所增加,分别从1982年的16.3 g·kg-1、40.88 t·hm-2上升到2007年的17.37 g·kg-1、43.31 t·hm-2。土壤有机碳随土壤类型的不同而变化复杂,土壤有机碳呈上升趋势的有潴育型水稻土、淹育型水稻土、渗育型水稻土,而沼泽型水稻土、潜育型水稻土和矿毒田呈下降趋势,主要旱地土壤类型（黄壤、红壤、红色石灰土、酸性紫色土）表层土壤有机碳质量分数呈上升趋势。从土地利用类型综合考量,水田、旱地表层土壤有机碳质量分数和密度都呈上升趋势,其中水田的有机碳质量分数和密度分别由80年代初期的18.30 g·kg-1、44.80 t·hm-2上升到2007年的18.78 g·kg-1、46.21 t·hm-2;旱地的有机碳质量分数和密度分别由80年代初期的10.46 g·kg-1、29.27 t·hm-2上升到2007年的13.17 g·kg-1、34.67 t·hm-2。粤北山区耕地表层土壤总体上表现为碳汇。