Seven Years of Change Following Liming of Sphagnum Communities in Sector Vii of the Loch Fleet Catchment

In 1986, application of lime within the upper wetland area of sector VII of the Loch Fleet catchment initiated numerous unscheduled small-scale experiments on the vegetation of this heterogeneous terrain. Vegetation changes and erosion were monitored in permanent or relocated plots established in 1987 and 1989 and re-surveyed in 1993, seven years after liming.

The most striking early effect, possibly occurring within a few weeks of lime application, was the death of Sphagnum papillosum carpet in soakways within the 2.5 ha area. Some patches of dead material were washed away, but bare surfaces were generally colonised by vascular plants, notably Juncus bulbosus. Effects in moorland and bog communities with dwarf shurbs were more subtle, involving reduction in Sphagnum cover and expansion of Erica teralix, Molinia caerulea, sedges and Narthecium ossifragum, but little change in the frequency of occurrence of Calluna vulgaris.     

Sustainable forest management practice in Central African States and customary law

Sustainable forest management (SFM) has become a major focus for the international community. This is because of the multifunctional importance of forest resources for the entire planet, namely ecological, socio-economic, cultural and climatic balance. General awareness of forest importance unfortunately coincides with the observed increase in threats, especially anthropogenic, to this world heritage. To tackle the continuing deforestation and degradation, the international community, through the United Nations Forum on Forests (UNFF) and its predecessors, has attempted to adopt an international convention on SFM based on the 15 Rio Declaration principles. The limited success of international negotiations aimed at the adoption of such an instrument leads us to seek an alternative within international law theories, through analysis of the relationship between states practice in SFM and customary international law. To this end, this paper focuses on the practice of Central African States in sustainable forest management, especially statement of principles, sub-regional treaty and domestic legislation. The analysis shows that their practice fulfils all the requirements in order to be regarded as regional custom. Therefore, principles and state practices of SFM can thus be considered legally binding for this sub-region, despite some major implementation shortcomings.     

Application of analytical hierarchy process and geographic information systems in land-use suitability evaluation: a case study of Dümrek village (Çanakkale,Turkey)

This study used both analytical hierarchy process (AHP) and geographic information systems (GIS) to make a land-use suitability analysis for the village of Dümrek, NW Turkey. Primarily, alternative land uses for agriculture, meadow–pasture and forest were determined along with criteria for these alternatives and a hierarchical structure was produced and used to determine the weights of the criteria. Spatial data were identified by means of GIS and calculations were made using the suitability values specified and weights obtained from AHP. Suitability maps were then produced for the above land use alternatives. Subsequently, a synthesized suitability map was formed from these maps. According to the weights specified by AHP, the order of land use preferences among the alternatives for rural development of Dümrek was agriculture, forest and meadow. The synthesized suitability map showed that the areas allocated for forest and agriculture were close to the present ratios of use; however, meadow land, which does not exist at present, should be allocated as a land use to constitute 12.5% of the study area. Achieving sustainability in land use is possible by planners and administrators considering results obtained from land suitability mapping studies at the stage of allocating land uses. The method applied in this research is considered useful when taking policy decisions covering the evaluation of rural land use, particularly for subunits of the state administration.     

南疆西部不同植被类型NDVI对风沙灾害的响应

不同植被类型对风沙灾害的响应研究有助于风沙灾害的遥感监测评估和防灾减灾工作。采用传统统计学和空间自相关方法,利用MODIS的每日反射率和土地类型产品,分析了风沙灾害后南疆西部不同植被类型NDVI的变化规律及其空间分布特征。结果表明：风沙灾害后,研究区不同植被类型NDVI的差异在增大,NDVI变化值在一0．3865~0．4148之间,NDVI减小的面积占整个研究区面积的54．98％,变异系数增大值在2．44％～36．75％之间;受到风沙灾害的影响,研究区植被NDVI全局Moran’SI系数从0．7982减小到0．6786,但在空间上仍存在显著的正相关性,具有显著的空间集聚特征;由NDVI差值的局部空间自相关指标集聚图以及不同植被类型NDVI差值的空间关联区域面积百分比,可以发现落叶针叶林和裸地或低植被覆盖地受风沙灾害的影响较小,郁闭灌丛和作物受风沙灾害的影响较大。上述关于风沙灾害后南疆西部不同植被类型的变化及其空间格局的研究结果,不仅证明了防护林的风沙阻挡作用,也可以为风沙灾害的防治工作提供参考依据。     

基于生态过程模型和森林清查数据的森林生长量估算对比研究

利用遥感驱动的生态过程模型-Boreal Ecosystem Productivity Simulator （BEPS）、2001-2006年国家森林资源连续清查数据（一类清查-样地尺度）和2003-2009年森林资源规划设计调查数据（二类调查-区域尺度）,分别计算江西省吉安市的森林生态系统生长量,从不同空间尺度和森林类型对3种数据源估算的森林生长量进行了分析。结果表明,样点尺度上,BEPS模型模拟的森林生长量（4.18 Mg·hm^-2·a^-1）低于群落生长量（5.86 Mg·hm^-2·a^-1）,与乔木层生长量（4.29 Mg·hm^-2·a^-1）基本一致,模型模拟结果与两者的拟合R2分别为0.48和0.43。区域尺度上,BEPS模型模拟、二类调查数据计算的群落及乔木层生长量分别为4.65、4.36和3.34 Mg·hm^-2·a^-1,BEPS模型估算的吉安市各县森林总生长量与二类调查数据计算的群落、乔木层生长总量拟合R2分别达0.84和0.83。一类清查数据计算结果高于二类清查数据计算结果,BEPS模型模拟森林生长量分别与基于一类清查数据计算的乔木层生长量及二类调查数据群落生长量较为一致。从研究区两种主要森林类型来看,常绿阔叶林年平均生长量高于常绿针叶林,常绿针叶林与模型估算结果差异小于常绿阔叶林。最后利用模型估算了研究区2001-2010年平均生长量,为认识研究区的森林生长空间分布差异及更新森林生物量提供支持。     

广东鹤山三种南亚热带人工林的生态系统服务价值动态

在鹤山国家森林生态系统定位研究站长期定位研究的基础上,参照和修订了我国LY/T 1721-2008《森林生态系统服务功能评估规范》给出的生态系统服务价值量化方法与服务价格,分析揭示了三种人工林生态系统0~22龄间的服务价值结构特点及其动态规律。结果显示：南亚热带人工林各生态系统服务呈现非线性、不同步的动态发展特征：涵养水源和总服务价值动态特征为先大幅上涨,然后上升速度减缓,最终维持在一定价值高度出现小幅波动;固碳释氧和林木积累营养物质价值动态特征为迅速增长,然后趋于缓慢下降;生物保育价值和保育土壤价值动态特征为一直处于上升态势,但上升过程中变幅较大。0~22龄间,涵养水源始终是三种人工林生态系统服务价值组成中的最大组分,其次是固碳释氧和生物保育。三种人工林相比,在12龄以前马占相思林生态系统服务总价值最高,之后三者生态系统服务总值差异明显变小,乡土混交林生态系统服务功能总价值逐渐超越马占相思林。     

上海海湾国家森林公园1 hm2样地群落结构特征及其动态监测意义

运用生态系统定位监测方法,于2011年在上海市奉贤区海湾国家森林公园内设置面积为100 m×100 m的样地,记录样地内的所有植物种类,定位调查高于1.3m的木本植物,分析其种类组成、区系成分、垂直结构和水平结构.结果表明,1 hm2样地内共记录有维管束植物31科68属73种,其中温带区系成分占总属数的51.8％,热带区系成分占46.4％.高于1.3m的木本植株3 094株,其中常绿树种6种,共1 670株,重要值占48.0％;落叶树种7种,共1 424株,重要值占52.0％.女贞(Ligustrum lucidum)、喜树(Camptotheca acuminata)、椤木石楠(Photinia davidsoniae)、乌桕(Sapium sebiferum)、黄山栾树(Koelreuteria integrifoliola)和香樟(Cinnamomum camphora)的重要值位居前6位,在垂直空间上呈分层结构.在0～50 m尺度范围内,女贞种群均呈集群分布,喜树种群呈均匀-随机-集群分布,椤木石楠和乌桕种群表现为集群-随机-均匀分布,黄山栾树和香樟种群表现为随机-集群-随机分布.从群落结构特征看,样地为以北温带成分、泛热带成分为主的常绿落叶阔叶混交林,表征了该地区自然植被的结构特征.建立长期固定样地可为长三角城市化地区平原地貌上城市森林的发生、发展和演替规律提供长期的数据基础.     

贵州西部4种林型土壤有机碳及其剖面分布特征

在气候变化背景下,森林土壤碳库已成为全球碳循环研究重点之一。以贵州西部桦木（Betula luminifera H.Wilk.）、柳杉（Cryptomeria fortunei Hooibrenk ex Otto et Dietr.）、华山松（Pinus armandii Franch.）和杉木（Cunninghamia lanceilata（Lamb.）Hook.）4种主要森林类型为对象,对其土壤有机碳、碳密度及其垂直分配特征等进行了研究。结果表明：4种林型土壤有机碳含量和碳密度均表现为华山松林（51.09 g.kg-1,30.56 kg.m-2）〉杉木林（39.47 g.kg-1,22.97 kg.m-2）〉柳杉林（37.49g.kg-1,21.00 kg.m-2）〉桦木林（36.31 g.kg-1,20.13 kg.m-2）,华山松林土壤有机碳含量和碳密度显著大于其它三种林型,而另外三种林型间差异不明显;4种林型土壤有机碳含量和碳密度均随土层深度增加而逐渐降低,土壤有机碳含量均为0-10 cm最大,分别是剖面均值的1.45-1.61倍,而0-20 cm层土壤碳密度占整个土壤剖面的32.69%-38.08%,显著高于其他各层,大于20 cm的土层中,各层间的变化较小,土壤碳密度具有一定程度的表聚性;4种林型土壤有机碳含量与土壤pH均表现极强的负相关,与土壤全N和碱解N均表现极强的正相关,与全P、速效P、全K、速效K和阳离子交换量的相关性不尽一致,建立的方程具有较高的回归精度,土壤N和P状况对4种林型土壤有机碳含量有重要影响。     

川西亚高山暗针叶林恢复初期土壤酶活性研究

研究以川西亚高山暗针叶林恢复过程中初级阶段的鲜类阔叶林（MBLF）、鲜类针阔混交林（MCBLF）和箭竹阔叶林（BBLF）土壤为研究对象,针对不同森林类型采用多点分层[0-10 cm（A层）、10-20 cm（B层）、20-30 cm（C层）和30-40 cm（D层）]采样、测定混合样的方式,研究了不同森林类型不同土层土壤的pH值、有机碳、全氮、全磷含量及脲酶、酸性磷酸酶、淀粉酶、过氧化氢酶、蛋白酶和蔗糖酶活性。研究结果表明,MBLF、MCBLF、BBLF不同土层土壤pH值均低于5.0,有机碳、全氮、全磷含量呈下降趋势,且有机碳、全氮与A层土壤差异显著（P〈0.05）。MBLF和BBLF随土层深度的增加脲酶活性较A层呈显著下降趋势（P〈0.05）,而MCBLF土壤脲酶活性以B、C层活性最高,分别为A层的1.22和1.08倍。蔗糖酶和酸性磷酸酶活性呈现先升后降的趋势,均以MCBLF活性最高;在林型MCBLF和BBLF中,随着土层深度的增加,蛋白酶和淀粉酶活性较A层显著降低（P〈0.05）,而MBLF、MCBLF、BBLF过氧化氢酶活性则一直呈显著下降趋势（P〈0.05）,D层过氧化氢酶活性分别为A层的60.21%、73.37%和46.84%。     

云南地区种子植物区系过渡性地理分布格局的群落尺度分析

探索植物区系过渡性的地理分布格局,对于理解植物区系的起源、迁移和分布具有重要意义。本研究利用620个植物群落样方,探讨了云南地区植物区系过渡性的地理分布格局及其生物地理意义。研究结果表明,随着纬度、海拔的升高,温带区系成分所占比重呈显著递增趋势,但在经度梯度上呈递减趋势;热带区系成分所占的比重在地理梯度上则表现为相反的变化趋势。地形格局较好地反映了区系成分的地理分布格局;热带区系成分所占比重与温带区系成分所占比重的比值从南到北呈递减趋势。区系过渡性的低值主要出现在滇西北地区和包括滇西南、滇东南与滇南在内的云南南部地区,而高值主要出现在云南中部地区和中海拔地区,这可能与区系迁移过程和海拔梯度有关。热带区系成分在云南地区基带植被中占主导地位;热带区系成分占优势地位的区域主要集中在低海拔地区,占云南土地面积的60％左右,而温带区系成分占优势地位的区域主要集中在高海拔的北部地区,占土地总面积的40％左右。本研究从基带植被的区系性质和温、热带植物区系成分占优势地位的土地面积的构成证实了云南地区可能是一个“热带山原”的假说。区系过渡性随着年平均温度的升高,呈先增强后减弱的单峰格局。当年均温在13．1℃左右时,出现区系平衡点。相对水平分布而言,云南地区植被的垂直分布可能更值得注意。