森林涵养水源功能及其生态补偿机制构建——以广西大瑶山自然保护区为例

对广西大瑶山自然保护区森林冠层、林下灌草层、林地枯枝落叶层及林地土壤层4个水文层次的涵养水源功能进行了效益计量调查研究,结果表明,该区森林植被总贮蓄水量为27508×104m3,年平均直接或间接的生态经济效益价值为3.75亿元,这对于维护周边地区的生态安全和可持续发展具有重要作用。根据该区森林涵养水源的效益计量调查状况提出了相应的生态补偿机制构建。     

黎塘岩溶区铁锰结核背景下的土壤研究

对黎塘岩溶区铁锰结核背景下的土壤进行了分析。结果表明：研究区土壤以硅质土为主,土壤发育呈幼年性。土壤多呈中性,对土壤肥力的发挥及旱地作物的生长较为有利;有机质含量A层多为中等（Ⅲ级）或丰富（Ⅳ级）,B层为缺乏（Ⅱ级）;全N含量A层多为中等（Ⅲ级）,B层多为缺乏（Ⅱ级）,有效N含量A层多为丰富（Ⅳ级）或甚丰富（V级）,B层多为中等（Ⅲ级）或缺乏（Ⅱ级）,A、B层养分含量的差异说明农耕区土壤受表层耕作、施肥影响较为显著。土壤有效P整体表现为缺乏或甚缺乏,可能已成为旱地作物生长的主要限制因子,阳离子交换量多表现为保肥力中等。     

河北省滨海平原区补充耕地等别评定研究

以河北省滨海平原区未利用耕地后备资源为主要研究对象,利用农用地分等成果,结合MAPGIS软件,运用土地开发整理项目设计标准和科学类比方法进行研究。确定评定补充耕地等别的指标区,建立未利用耕地后备资源数据库。在进行耕地适宜性评价基础上,依据土地开发整理项目设计标准和农用地分等成果确定补充耕地等别评定各因素分值,计算补充耕地等别,制定滨海平原区占补折算系数表。     

黑里河天然油松林生态类型与结构初步分析

对黑里河天然油松林的群落结构、类型、生长状况、更新演替等进行初步分析,为油松天然林的深入研究和自然保护区的合理经营及有效管理提供理论依据。     

桂林岩溶石山青冈栎种内与种间竞争的数量关系

根据野外调查数据,采用Hegyi单木竞争指数模型,定量地研究了桂林岩溶石山建群种青冈栎的种内、种间竞争关系.结果表明,青冈栎所受到的竞争强度随着林木径级的增大而逐渐减小,种内竞争明显较种间竞争剧烈.青冈栎种内和种间竞争强度的顺序为:青冈栎＞石山樟＞亮叶槭＞圆叶乌桕＞光叶海桐＞翅荚香槐＞梧桐＞黄连木＞铁屎米＞粗康柴.整个林分以及青冈栎种内对对象木的的竞争强度与对象木胸径之间的关系近似服从幂函数关系,而伴生树种对对象木的竞争强度与对象木胸径之间的关系近似服从对数函数关系,对象木胸径与竞争强度间呈显著负相关关系.     

多宝山铜矿开发的必要性及对其资源环境的影响

以黑龙江多宝山铜矿为例,探讨了开发东北、内蒙地区国有林区大型矿区的深远影响,并从生物多样性、生态效能、景观风貌、环境质量等多方面着手,重点分析了开发多宝山铜矿对国有林区森林资源和生态环境的影响,最后提出了相应的建议与措施。     

不同浸提剂处理森林土壤溶解性有机碳含量比较

为了解亚热带森林土壤溶解性有机碳(DOC)的特征规律,采用培养离心的方法获取土壤溶液测得DOC含量,对比传统水溶性有机碳(WSOC)提取法间的差异。选取湖南大山冲森林公园保存完好的3种亚热带典型次生林地,按10cm一层采集剖面土壤,采用不同方法提取测定土壤DOC和WSOC含量,分析与土壤理化指标的相关性及方法间的显著性关系。结果表明:①典型森林土壤DOC或WSOC含量随土壤剖面深度的增加,呈显著下降趋势。培养离心提取测得的土壤DOC含量明显较低,仅0.82～9.52 mg/kg,超纯水浸提的风干土WSOC含量达10.56～249.19 mg/kg,而0.5 mol/L K₂SO₄提取的鲜土WSOC含量达155.70～576.94 mg/kg,0.5mol/L K₂SO₄浸提的干土WSOC含量最高,达158.94～797.56 mg/kg,含量表现为:DOC<干土超纯水浸提WSOC<鲜土K₂SO₄浸提WSOC<干土K₂...     

How good are managed forests at conserving native woodpecker communities? A study in sub-Himalayan dipterocarp forests of northwest India

We assessed the impact of forest management on woodpecker community structure sub-Himalayan dipterocarp sal (Shorea robusta) forests. We selected eight sites representing four management-based ‘forest types’ (natural unworked sal, old- and young managed sal, and teak plantations). At each site, bird surveys were conducted along 2-km-long transects, 20 times during breeding and non-breeding seasons. Habitat characteristics were enumerated using circular and belt plots. Species composition across forest types was compared using multi-response permutation procedures. Indicator analysis identified woodpecker species preferring particular forest types. Biomass, abundance, and mean species richness of woodpeckers were highest in natural sal, intermediate in managed sal, and lowest in teak. There were apparent differences in woodpecker densities between seasons. Densities were higher in breeding season than non-breeding season for natural sal, while the opposite was true for managed sal. Woodpecker species composition significantly differed across forest types. The four largest species, including grey-headed (Picus canus) and greater yellownape (Picus flavinucha) that were identified as indicators, predominated natural sal but were scarce in other types. At a broader level, mean species richness of woodpeckers strongly indicated mean richness of other avifauna during breeding season. Our study suggests that forest management has significantly altered the sub-Himalayan woodpecker community structure. Managed sal forests, particularly teak plantations, are largely unable to support the original woodpecker assemblage during breeding season, although they provide foraging grounds during non-breeding season.     

围栏封育对红松洼自然保护区草原植物群落特征及多样性的影响

以红松洼自然保护区草原植物群落为研究对象,采用样方法对研究区2012—2016年连续5年围栏封育植被进行了调查分析。结果表明:围封5年的植物群落优势种并未发生明显更替变化,但随围封年限增加,围栏内优势种及其他物种的重要值发生改变,其中地榆(Sanguisorba officinalis)、裂叶蒿(Artemisia tanacetifolia)重要值明显增加,细叶苔草(Carex rigescens)降低最多。围栏封育使植物群落的高度、盖度、生物量均明显增加(p0.05)。从不同经济类群分析,其优良牧草类、药用类植物比例增加,而杂类草比例相对下降。围封5年,植物群落丰富度指数、物种多样性指数、均匀度指数显著增加(p0.05)。     

Linking past land use, recent disturbance, and dispersal mechanism to forest composition

Many areas in north-eastern North America were historically cleared for agriculture and subsequently abandoned. The resulting woodlots are exposed to varying degrees of recent disturbance. This paper examines the contributions of land use history and recent disturbance on the species richness and community composition of wooded areas in an agricultural landscape. Woodlots were categorized according to land clearance history, past grazing, and recent disturbance, such as the presence of roads or selective cutting. Vegetation surveys resulted in the identification of 250 herbaceous plant species, 44 of which were classified as exotic. While no influence of recent disturbance on community composition was detected, past land use influenced species richness for all plant groups examined. General linear models indicated that herbaceous, native, and forest species richness was highest in historically partially cleared sites; while exotic and invasive species richness was greatest in historically cleared sites. Non-metric multi-dimensional scaling (NMS) ordination was used to identify associations between community assemblage, land use history, and dispersal mechanism. The two axes of the NMS ordination explained 79.2% of the variation in the data, and indicated that woodlots completely cleared in the past were associated with wind dispersed species indicative of disturbed habitats. In contrast, historically uncleared sites contained short-distance dispersed species indicative of rich woods. Although no effects of recent disturbance were detected, the long lived impacts of past land use and the increase of exotic and invasive species in historically cleared indicate that undisturbed woodlots should be considered of highest conservation importance.