海南岛尖峰岭热带山地雨林林下鸟类群落研究

从 2 0 0 0年 5月到 2 0 0 2年 3月 ,用网捕法对海南岛尖峰岭热带山地雨林 (包括原始林和次生林 )林下鸟群落进行研究。共张网 3 992 .7网· h,捕到林下鸟 3 12只 40种 ,隶属于 6个目 11个科。林下鸟群落虽然以小于 2 5g重的雀形目鸟类占优势 ,但许多个体较大的非雀形目鸟类也到林下活动 ,最大个体重达 3 70 g,大于 10 0 g重的个体占整个林下鸟生物量的比例较大。尖峰岭热带山地雨林中的林下鸟以食虫鸟为主 ,食虫鸟占整个林下鸟种数的 70 .0 %、鸟数量的 77.56% ;食果鸟虽然占第 2位 ,但其所占比例较小。林下鸟的种类组成和密度存在季节变化。留鸟是林下鸟最重要的成分 ,留鸟占鸟类种类的比例超过 85% ,留鸟的捕获数量占整个捕获鸟类数量的比例超过 90 % ;迁徙鸟的种类和数量均较少 ,对林下鸟群落的季节变化影响不大。原始林与演替 40 a后的次生林林下鸟平均网捕率相近但林下鸟群落种类组成不同 ,其种的相似性仅为 0 .3 5。     

Responses of an avian community to rain forest degradation

Cumulative impacts of logging and road building in a previously undisturbed tract of tropical rain forest in French Guiana were assessed by random sampling of the bird community and 1-km² plot counts of diurnal raptors. Similar surveys were carried out during road construction and 15 years later within 5km of the road and were also compared with the undisturbed bird community of a nearby primary forest. The main disturbance was the change in forest structure brought about by logging and secondarily the road opening, the roadside second growth and the depletion of large vertebrates by hunting pressure. The responses of different bird guilds were highly divergent according to their natural habitat requirements, their diet and their vulnerability to hunting. They resulted in a moderate decrease in overall species richness and equitability. All species pooled, the abundance of 118 species was lowered, that of 45 species did not change appreciably and 89 were favored or even appeared. The guilds most affected were those with large body sizes, from terrestrial foragers to canopy frugivores, mostly by hunting, and the open understorey specialists, notably large insectivores and mixed flock members, because of changes in forest structure after logging. The guilds favored by logging and road opening were many of the hummingbirds, upper canopy frugivores and omnivores, and gap, edge or low secondary growth specialists. Recommendations to minimize the negative consequences of human exploitation in rain forests include reducing the width of deforested roadsides to no more than 10–15m on either side, implementing much more careful logging practices and strongly limiting hunting pressure in newly opened areas.     

Tree community diversity of lowland swamp forest in Northeast Costa Rica, and changes associated with controlled selective logging

In the Atlantic lowlands of Northeast Costa Rica, logging occurs in tracts of poorly drained wet forest ('swamp forest'), yet little is known about factors affecting swamp forest diversity or the potential for biodiversity retention during harvest. This paper quantitatively describes the species composition and diversity of the swamp forest habitat, and reports the immediate impact of controlled, selective logging on tree community diversity. Pentaclethra macroloba (Leguminosae), Carapa nicaraguensis (Meliaceae) and Pterocarpus officinalis (Leguminosae) accounted for >70% of the primary swamp forest basal area. Nevertheless, 225 species from 53 families with individuals 10cm dbh were encountered in 16.4 ha; most species had very low abundances. Gamma diversity is a component of overall swamp forest diversity. Extraction of 49.2m3ha–1 (5.5 trees ha–1) of timber from a 4ha plot reduced species richness by 14, supporting assertions that random mortality during logging can affect the distribution of rare species. However, tree community diversity as measured by rarefaction was not greatly affected by selective logging. Total post-logging stem recruitment over a 3-year period was greater in logged plots than in undisturbed plots; the recruitment of the ruderal species Ochroma lagopus (Bombacaceae) was the most clearly affected by logging. Any localized dominance by this species will be limited in space and time in a carefully managed forest. The results suggest that controlled selective logging can be consistent with biodiversity conservation, and complement protected areas in Northeast Costa Rica.     

Mean latitudinal range sizes of bird assemblages in six Neotropical forest chronosequences

Aim The geographical range size frequency distributions of animal and plant assemblages are among the most important factors affecting large‐scale patterns of diversity. Nonetheless, the relationship between habitat type and the range size distributions of species forming assemblages remains poorly understood. We examined how the mean latitudinal range sizes of species in Neotropical bird species assemblages shift during forest clearance and subsequent regeneration. We tested the hypothesis that bird species assemblages in early successional habitats tend to have larger latitudinal ranges than those in more mature forests. Location We considered breeding bird chronosequence data from six Neotropical forests. Results Breeding bird assemblages were found to have the species with the largest average latitudinal range sizes in cleared areas, intermediate in young secondary forests and smallest in old secondary and mature forests. Similar differences were also found when we compared congeners differing in their successional preferences. Sizes of regional ranges (within the Neotropics) did not, however, differ consistently among successional stages. The larger latitudinal (but not regional) ranges of early successional species was as a result in part of the tendency of early successional species to have ranges that extend beyond the Neotropical forest biome. Conclusions Our analysis of chronosequences suggests that as early successional habitats mature, a consistent shift from large‐ranged species towards more small ranged species occurs. Even relatively old secondary forests have bird species with larger average ranges than mature forests. As a consequence, conservation of secondary forests alone will miss many of the species most at risk of extinction and most unlikely to be conserved in other locations or biomes.     

Effect of selective logging on forest structure and nutrient cycling in a seasonally dry Brazilian Atlantic forest

Aim The Brazilian Atlantic forest covers c. 10% of its original extent, and some areas are still being logged. Although several ecological studies in Atlantic forest have been published over the past two to three decades, there has been little research on forest dynamics and there is a particular lack of information on the effects of disturbance. The aim of the present study was to assess the impact of selective logging on forest structure, floristic composition soil nutrients, litterfall and litter layer in a seasonally dry Atlantic forest. Location The Mata do Carvão is located in the Guaxindiba Ecological Reserve in São Francisco do ltabapoana district (21°24′ S, 41°04′ W), Rio de Janeiro, Brazil. Methods Four plots (50 × 50 m) were set up in 1995 in each of two stands: unlogged and logged. In each plot, all trees ≥ 10 cm d.b.h. were enumerated, identified and measured. Vouchers were lodged at UENF Herbarium. Five surface soil samples were collected in each plot in the dry season (in October 1995). Litterfall was collected in eight traps (0.50 m²) in each plot over a year from 14 November 1995 to 11 November 1996. The litter layer was sampled in eight quadrats (0.25 m²) in each plot in the dry and wet seasons. Soils were air‐dried, sieved, and chemically analysed. The litter was dried (80 °C), sorted into six fractions, weighed and bulked samples analysed for nutrients. Results Forest stands did not differ in stem density and total basal area, with a total of 1137 individuals sampled in 1996 (564 unlogged and 573 logged), and a total basal area of 15 m² (unlogged) and 13.0 m² (logged). However, unlogged stands had more large trees (≥ 30 cm in d.b.h.) and greater mean canopy height. Among the families, Rutaceae and Leguminosae were the most abundant families in both sites, although the Rutaceae had a higher density in unlogged and Leguminosae in the logged stand. The species diversity index was similar between stands. Late‐successional species, such as Metrodorea nigra var. brevifolia and Paratecoma peroba, were less abundant in the logged stand. Selective logging did not affect nutrient concentrations in the soil or in the litter. However, quantities of the nutrients in the total litterfall and in the leaf litterfall and litter layer were higher in unlogged than in logged stands, mainly as a result of fallen M. nigra leaves. Metrodorea nigra was considered a key species in the nutrients dynamics in Carvão forest. Main conclusions Despite the fact that effects on tree diversity and soil nutrients were not clear, selective logging in this Atlantic forest altered canopy structure, increased the relative abundance of some early‐secondary species and decreased the litter input and stock of nutrients. Detailed information on the influence of logging on the distribution and structure of plant populations and in nutrient processes is fundamental for a sustainable logging system to be developed.     

Impact of logging on the richness and diversity of forest butterflies in a tropical dry forest in Thailand

Studies on the impact of logging on tropical forest butterflies have been almost exclusively conducted in moist forest habitats. This study considers the impacts of small-scale logging on butterfly communities at three sites of varying disturbance intensity in a tropical dry forest in western Thailand. Butterfly species richness was similar at all sites, but the abundance of butterflies and diversity of the butterfly community decreased with increased logging disturbance. The recorded decrease in diversity at the relatively large sampling scale used lends further support to the hypothesis that disturbance effects are scale dependent. Species abundance data for butterflies fitted a log-normal distribution at all sites, but also a log-series distribution at the two disturbed sites. These analyses suggest a more complex butterfly community at the undisturbed site, but also that log-series and log-normal distributions may not to be sufficiently sensitive to be useful indicators of community changes following logging. Community ordination separates both the butterfly species and transect samples into three distinct regions corresponding to the three study locations. Ordination axes are correlated with tree density, understorey cover and understorey plant richness. Species with the smallest geographic ranges tend to be the least abundant and occurred most frequently in the undisturbed site. The observed diverging responses to disturbance among butterfly families diminishes the value of butterfly communities as biodiversity indicators, and forest managers should perhaps focus on restricted range species or of groups of recognized sensitive species for this purpose.     

The functional importance of rare and dominant species in a Neotropical forest bird community

Bird communities in Tropical forests have high rate of rare species, but only recently some studies suggested their disproportional role for the overall functional diversity. We investigated data from bird communities monitored annually using point counts over ten years in Iguassu National Park, that is a large and protected area in the southern portion of the Atlantic Forest in Brazil. We aimed (1) to determine the rare and dominant species in the community based on their abundance over time; (2) to evaluate the impact of each class of rarity on the overall functional volume of the community; (3) to investigate the pattern of occupancy of the trait space filled by each dominance class, and (4) to assess the disparity in functional trait composition between classes of rarity. We defined dominant, intermediate, and rare species in communities using cluster analysis and data of relative abundance of species in five sections of 1-km in the forest interior. The number of clusters was defined in accordance with the silhouette criterion measures of cohesion and separation that range from −1 to 1, with values > 0.5 indicating high-quality clusters. Among total 138 bird species recorded, 107 were rare, 26 intermediates, and 5 dominants. Our data corroborate a functional disproportional importance of rare bird species in the community considering the functional space (FRic), but functional dispersion (FDis) was not significantly different between the rare and intermediate species. In fact, there is a large overlap of the functional volume occupied by rare in relation to dominant/intermediate species. The niche space occupied by rare species covers most of the space occupied by intermediate and dominant species. The low representativeness of functional turnover indicates that few functions are unique to the classes of higher dominance. Our data suggest the importance of rare bird species to the overall functional diversity but also highlights the potential use of dominants/intermediates species as indicators to select important forests areas for conservation, as certain forest fragments. Through these most abundant species it would be possible to assess which functions are heaviest in abundance, becoming core functions, in the context of each independent forest fragment.     

Avian responses to selective logging shaped by species traits and logging practices

Selective logging is one of the most common forms of forest use in the tropics. Although the effects of selective logging on biodiversity have been widely studied, there is little agreement on the relationship between life-history traits and tolerance to logging. In this study, we assessed how species traits and logging practices combine to determine species responses to selective logging, based on over 4000 observations of the responses of nearly 1000 bird species to selective logging across the tropics. Our analysis shows that species traits, such as feeding group and body mass, and logging practices, such as time since logging and logging intensity, interact to influence a species'' response to logging. Frugivores and insectivores were most adversely affected by logging and declined further with increasing logging intensity. Nectarivores and granivores responded positively to selective logging for the first two decades, after which their abundances decrease below pre-logging levels. Larger species of omnivores and granivores responded more positively to selective logging than smaller species from either feeding group, whereas this effect of body size was reversed for carnivores, herbivores, frugivores and insectivores. Most importantly, species most negatively impacted by selective logging had not recovered approximately 40 years after logging cessation. We conclude that selective timber harvest has the potential to cause large and long-lasting changes in avian biodiversity. However, our results suggest that the impacts can be mitigated to a certain extent through specific forest management strategies such as lengthening the rotation cycle and implementing reduced impact logging.     

Altitudinal and latitudinal distribution of east Malagasy forest bird communities

Aim To describe variation in forest bird communities with altitude and latitude. Location Eastern Madagascar. Methods Extraction of data from forest bird inventories conducted in eastern Madagascar. Results There is a strong decline in species richness with altitude, above about 1300 m. Below this altitude, species richness is about constant or declines slightly. Seventy-eight percent of species occurring regularly in forest are absent from at least one of low, mid-altitude or high altitude forest. Of eighty-seven species occurring regularly in forest, only four or possibly five have latitudinally limited distributions, over a latitudinal range of over 1200 km. Three or possibly four are limited to the northern two-thirds, and one appears to be at least much more common in the southern half. Main conclusions Eastern Malagasy rain forest birds show previously unanalysed variation in altitudinal distribution. There is much less latitudinal variation. Species currently considered threatened are concentrated in the lowland and high-altitude zones. This may be at least partly due to lack of survey effort giving the impression that these species are rare, but lowland forests at least are under great human pressure. Bird conservation initiatives would probably have most effect if targeted at lowland east Malagasy rain forest.     

人为干扰对城市森林灌草层植物多样性的影响——以厦门市为例

以厦门城市森林林下层植被为研究对象,重点研究台湾相思群落中林下灌草层植物多样性与土地利用类型、人为干扰程度之间的相关性;选用基于重要值的4种多样性指数,比较不同邻接用地类型城市森林群落多样性的差异;运用主成分分析、CCA排序以及多元回归等方法对城市森林灌草层植物多样性格局进行解释.结果表明:人为踩踏、垃圾堆积程度、人为挖掘、可到达容易程度等因子对厦门城市森林灌草层植物多样性分布格局有重要影响;厦门城市森林群落草本层β多样性沿着邻接商业用地、交通用地、工业用地、居住用地的方向逐渐增加,而灌木层β多样性沿着该环境梯度的方向却逐渐降低.     

Role of magpie in bird community formation in secondary forest

We analyzed a bird community in a secondary forest and the results show that the magpie was one of the key groups in the secondary forest. The key group is identified based on the nests used by other birds at a rate of 25%–40.17%. The size of the community is different and the number of these key groups is not certain. __________ Translated from Journal of Northeast Normal University (Natural Science Edition), 2006, 38 (3): 644-651 [译自: 东北师大学报(自然科 学版)]     

Role of magpie in bird community formation in secondary forest

We analyzed a bird community in a secondary forest and the results show that the magpie was one of the key groups in the secondary forest. The key group is identified based on the nests used by other birds at a rate of 25%-40.17%. The size of the community is different and the number of these key groups is not certain.     

香港大埔滘天然次生林鸟类群落结构变化

观察了香港最大的大埔滘天然次生林内鸟类群落结构在10a间的变化。用t檢验比较了1993~1995年和2003~2005年间的10种数量最高的鸟类的密度变化。所有的泛生境留鸟种类的密度均呈显著减少。两种树林种类的密度有显著増加,其中一种是本土种,另一种是外来种。香港树林鸟类群落的变化趋势主要受到两个因素的影响,包括缺少有树林种类鸟居住的树林,和外来种的入侵。     

森林采伐对尖峰岭海南特有种子植物多样性的影响

特有种子植物是热带森林植物区系的一个重要组成部分,且很容易受到人为干扰的影响,但是森林采伐对特有种子植物的影响少有报道。本文基于164个25m×25m植被公里网格样地数据,分析了海南岛尖峰岭地区海南特有种子植物(以下简称特有种子植物)的组成结构、样地内特有种子植物物种数与总物种数之间的关系;并从种-面积曲线、累积种-个体关系和物种多度分布3个方面比较了原始林、径级择伐林和皆伐林样地中特有种子植物的物种多样性变化规律。结果显示:尖峰岭地区特有种子植物种类丰富,共有158种,占全岛(397种)的40%;其中木本特有种子植物达98种(藤本除外),在164个样地内共记录到胸径≥1.0cm的52种,占整个尖峰岭地区的53%,以樟科、壳斗科、茜草科种类为主。样地内特有种子植物的物种数与总物种数成正相关关系。采伐后特别是径级择伐后特有种子植物物种数略微增加,但增加的种类大多仅在1-2个样地中出现;而且种群也比较小,表现为较稀有且不稳定的种群结构特征,在后续的更新中消失的可能性较大。但是,采伐后一些特有种子植物仍具有中等大小的种群,例如毛荔枝(Nephelium topengii)、海南紫荆木(Madhucaha inanensis)和尖峰岭锥(Castanopsis jianfenglingen-sis)等。     

长江师范学院校园夏季鸟类群落与多样性分析

2008年3～7月采用样线法对长江师范学院李渡校园鸟类组成和种群数量进行了调查,共记录鸟类6目21科28种,数量1633只,物种多样性指数为3．9204,均匀性指数为1．1765,其中国家“三有”名录鸟类25种,CITES名录鸟类1种。鸟类区系以东洋界成分为主。对不同生境鸟类多样性的分析结果表明：（1）乔灌林鸟类多样性指数和均匀性指数最高,水域鸟类多样性指数最低,建筑区均匀性指数最低;（2）乔灌林与竹林的相似性指数最高,竹林与水域的相似性最低。     

Bird diversity and abundance in forest fragments and Eucalyptus plantations around an Atlantic forest reserve, Brazil

Little of Brazil's remaining Atlantic forest is protected, so it is important to assess how well the region's wildlife can persist in areas/habitats outside reserves. We studied bird diversity and abundance during 546 point counts in the Sooretama/Linhares reserve, 200 point counts in 31 forest fragments (10–150 h), and 50 point counts in <30-year-old Eucalyptus plantations, within 7 km of the reserve. Only eight bird species were recorded in Eucalyptus, and this impoverishment, as compared to some Eucalyptus plantations elsewhere in Brazil may be a result of intensive clearance of understory vegetation. Species diversity in forest fragments was significantly lower than in the reserve. Twelve, mostly non-forest or edge species, were significantly commoner in the fragments, but nineteen species were frequent in the reserve but rare or absent in forest fragments. These included two Pyrrhura parakeets, a Brotogeris parakeet, a trogon Trogon, a jacamar Galbula, woodpeckers Piculus and Campephilus, Myrmotherula antwrens, and Hemithraupus and Tachyphonus tanagers. Bird species richness at points in forest fragments did not decline with fragment size, distance from the reserve, or forest quality. However, forest in fragments was more heavily degraded than forest within the reserve and poor forest quality may be the cause of declines in some species. Whilst protection of forest within reserves is a priority, management of forest fragments may aid conservation of some threatened species.     

Effects of selective logging (50 years ago) on habitat use and ranging behaviour of a forest understorey bird (red-tailed bristlebill, Bleda syndactyla) in Uganda

To understand the effects of selective logging on animals we compared habitat use and ranging behaviour of a common understorey passerine bird, the red‐tailed bristlebill (Bleda syndactyla), in logged and unlogged forest in the Budongo Forest Reserve, Uganda. The secondary forest had been selectively logged about 50 years ago, and differed in vegetation structure from the unlogged, primary forest in particular by having a denser understorey. Home range size of radio‐tagged bristlebills was 10–20% larger (depending on data sample used) in unlogged forest compared with logged forest, but the difference was not significant. Movement rates during 1‐h observation periods were highest in unlogged forest. The bristlebill has been characterized as a bird of dense understorey vegetation, and data from unlogged forest in the present study suggested that areas with dense understorey were used more often than expected. In logged forest, no habitat preferences were found, probably because the forest had a dense understorey throughout. Assuming that smaller home ranges and lower movement rates indicate better habitat, there was no evidence that bristlebills were negatively affected by logging. The preference for dense understorey in unlogged forest suggests that the bristlebill may benefit from selective logging because this leads to an increase in dense understorey.