化学防治对马尾松林蜘蛛群落结构的影响的研究

１９９５年７月至１９９６年６月在湖南长沙县马尾松林内用溴氰菊酯和灭幼脲ＩＩ号作的喷药试验．结果表明：两种药剂对蜘蛛群落的物种组成和个体水平有明显影响，对物种数量影响不大．在试验过程中，其多样性水平有一定程度上升，防治效果显著的样地内群落稳定性改善．同时，两种药剂对灌木层亚群落影响要大于对林冠层的影响；在生产管理上，灭幼脲ＩＩ号可用于防治常灾区，而溴氰菊酯只宜在重灾区内集中施用．     

The effect of thinning on ground spider diversity and microenvironmental factors of a subtropical spruce plantation forest in East Asia

Currently, information about the effect of forest management on biodiversity of subtropical plantation forests in Asia is quite limited. In this study, we compared the spider community structures and guild compositions of subtropical Cryptomeria japonica plantation forests receiving different degree of thinning (0, 25 and 50 %) in central Taiwan. The ground spider diversities and environmental variables were sampled/measured once every 3 months for 1 year before thinning and 2 years after thinning. Results showed that before thinning spider compositions did not differ significantly among three plantation forest types. Two years after thinning, spider species and family compositions of three plantation forest types differed significantly. In all three plantation forest types, the spider composition differed from year to year, indicating existence of temporal variations in spider diversity. Ground hunters (increased 200–600 % in thinned forests), sheet web weavers (increased 50–300 % in thinned forests) and space web weavers (decreased 30–50 % in thinned forests) were the major contributors of the observed spider composition differences among plantation forests receiving different treatments. The stands receiving thinning treatments also had higher illumination, litter decomposition rate, temperature and understory vegetation density. Thinning treatments might have changed the structures of understory vegetation and canopy cover and consequently resulted in abundance and diversity changes of these guilds. Moreover, the heterogeneity in understory vegetation recovery rate and temporal variation of spider composition might further generate spider diversity variations in subtropical forests receiving different degree of thinning.     

Partial cutting does not maintain spider assemblages within the observed range of natural variability in Eastern Canadian black spruce forests

In boreal black-spruce forests of Eastern Canada, a cohort model of ecosystem management has been proposed whereby a combination of both partial and more intensive cutting are used to emulate old-growth stands and the re-establishment of stands following severe wildfire. As with other approaches to coarse filter conservation, partial cutting is hypothesized to maintain and potentially recreate plant and animal assemblages consistent with a range of natural variability. In this study, we used ground-dwelling spiders (Araneae) to evaluate whether partial cutting and a cohort model of ecosystem management are sufficient to preserve biodiversity found in mature and over-mature boreal black spruce stands prone to paludification. We compared the spider fauna (11,628 individuals representing 136 species) in replicated partial cuts, clear cuts and uncut control stands with a chronosequence of mature and over-mature naturally regenerated stands (94-288 years since the last fire) [25 stands in total] in the same region of the northern Clay belt in Québec (Canada). In stands that were old-growth prior to cutting, harvesting had strong repercussions on spider assemblages that were not attenuated by less intensive, partial cutting. The most obvious changes in spider assemblages were related to increased recruitment of species that were nearly absent in uncut stands. Several cosmopolitan species that were widely distributed among stands prior to harvest increased in cut stands. Spider assemblages collected following either cutting methods were not consistent with assemblages found within the chronosequence and thus fell outside the observed range of natural variability. However we did not observe a similar recruitment effect for spider species in younger stands with relatively higher levels of retention. We demonstrate that the interaction between stand age prior to cutting, the degree of paludification as well as remnant basal area are important considerations when evaluating the efficacy of partial cutting to maintain forest spider assemblages and biodiversity at large in black-spruce stands. “We also suggest that retention levels in partial cuts will have to be substantially increased to maintain spider communities within their range of natural variation in managed forested landscapes.” However partial cutting with higher levels of retention, particularly in younger stands, may be useful in coarse filter management particularly for establishing or accelerating spider assemblages towards those found in old-growth stands.     

溴氰菊酯对马尾松林昆虫群落多样性的影响

１９９５年７月至１９９６年６月,在湘中丘陵区马尾松林内用溴氰菊酯进行喷药防治害虫试验结果表明,溴氰菊酯对林内昆虫群落的物种丰富度和多样性均有影响．其中植食类群受影响的主要是同翅目、直翅目、鳞翅目、鞘翅目和半翅目昆虫,捕食类群主要是蚂蚁和蜘蛛．在药剂作用下,植食类群和寄生类群的物种丰富度及多样性水平均呈现下降,捕食类群的物种丰富度虽有所下降,但在整个群落中所占的比例及多样性水平均有较大程度的上升．施用溴氰菊酯可降低植食物种的优势度,提高天敌类群与植食类群之比值,使昆虫群落在一定时间内保持相对稳定．但它降低了群落内物种的丰富度（特别是稀有种和偶见种）及多样性水平,因此在生产上用其防治松林害虫时不宜在大面积范围内长期使用．     

Habitat structure influences the spider fauna of short-rotation poplar plantations more than forest age

Plantation forests comprise an important part of the forested areas in European countries. Intensive forestry management and short-rotation cycles of plantation forests reduce habitat diversity and change the composition of invertebrate assemblages, mainly by reducing the number of habitat specialist species. Here, we analysed the effect of vegetation structure, amount of dead organic matter (DOM) and plantation age on spider functional diversity and assemblage structure in short-rotation plantations of native silver poplar in Hungary. Three stages, representing young plantations, 6- to 10-year-old stands (five stands), middle-aged plantations, aged between 23 and 26 years (five stands) and mature, 35- to 37-year-old forests at commercial maturity (five stands) were sampled. Each sample consisted of the data of ten pitfall traps. Traps were installed 5 m from each other in a 2 × 5 grid. Functional diversity was positively related to vegetation structure. High functional diversity indicates a higher number of available niches and potential resources. The abundance of moist habitat species and forest specialist species was positively correlated with DOM. Furthermore, moist habitat species were also related to vegetation structure. The most important environmental parameters affecting spiders were factors attributed to trees (litter and DOM), understory vegetation structure and, to a lesser extent, forest age. Different-aged stands may be similar in terms of species composition of their spider fauna if they comprise the same habitat structural patterns. Our study emphasises that the simple habitat structure of plantation forests has a negative effect on spider communities.     

Comparison between old-growth stands and secondary stands regenerating after clear-felling in warm-temperate forests of Yakushima, southern Japan

In order to infer successional changes in structure, species composition and diversity of warm-temperate forest, we compared secondary stands regenerating after clear-felling (41–64-years old) with old-growth stands at altitudes between 300 and 800 m on Yakushima Island, southern Japan. Stem density and maximum stem diameter differed between secondary and old-growth stands, but basal area and aboveground biomass did not. At lower altitudes, the dominant species in old-growth stands with a strong sprouting capacity (Castanopsis cuspidata) also dominated secondary stands, and species composition of secondary and old-growth stands was similar. At higher altitudes, by contrast, the dominant species in old-growth stands (Distylium racemosum) had little sprouting capacity and was poorly represented in diverse secondary stands, which were dominated by Castanopsis or other less abundant species. Secondary stands had greater species diversity (Shannon–Wiener index) than old-growth stands, particularly at higher altitudes. This was due to greater species richness resulting from higher stem density per area, but not to greater evenness. We grouped the component species that share ecologically similar traits into four guilds (fagaceous, primary evergreen, secondary evergreen and deciduous species). Secondary stands were characterized by greater numbers of deciduous and secondary evergreen species. We concluded that different sprouting capacities of dominant species and different regeneration traits among guilds are responsible for the change in species composition and diversity during succession.     

杏树林害虫为害与发生规律

为全面了 解杏树林 害虫的 为害与 发生 规 律, 给 防 治提 供依 据, 采用 标 准地 方法 对 不同类型的 杏扁林进 行了系 统调查。 结果表明 , 杏树林 害虫群 落共有６ 目２５ 科５５ 种, 优势 种集中于蚧虫 、蚜虫、卷 叶蛾等 类群及天 幕毛虫、 舞毒 蛾等 。树 木 年龄 可 影响 害 虫 群落 的 组 成、优势种数 量及危害 程度 。管 理水 平 对 害虫 发 生 有明 显 影响 , 一 般 管理 水 平高 者, 害 虫 种类 少、危害较轻 。杏树林 害虫的 年发生规 律 是发 生周 期 短、优 势 种高 峰期 出 现早 、为 害期 集 中、群落凋落 迅速。     

马尾松林昆虫群落及其时空结构的研究

本文对湖南省靖县排牙山林场六种不同类型马尾松林的昆虫群落(包括蜘蛛)进行了初步研究。在所获688种昆虫和蜘蛛中,没有一种在群落中占有绝对优势,其数量分布比较均匀。研究结果表明:不同类型的林分,其昆虫群落的稳定性有差异。在林龄和郁闭度这两个重要的林分因子中,以林龄对稳定性的影响较大。本文提出用昆虫群落多样性指数变化的年极差(ED)及天敌/害虫比值(NE/P)这两个指标来评定群落的稳定性,试图从实质上阐明昆虫群落是否稳定的原因。在马尾松林由幼林向中林、成林发育的过程中,昆虫群落的天敌数量逐渐增多,害虫数量则相对减少,因而昆虫群落的自控能力亦逐渐增强,使之由比较不稳定到比较稳定。 马尾松;;昆虫群落;;多样性指数