Evaluating the effect of habitat diversity on the speciesarea relationship using land-bridge islands in Thousand Island Lake,China

DEAR EDITOR：The species-area relationship（SAR）describes the phenomenon whereby the number of plant and animal species found in an area of wild habitat is strongly correlated with the size of that area.As one of the few ecological laws,the SAR plays a vital role in the design and assessment of biodiversity protection regions（Lomolino et al,2010;Ladle＆Whittaker,2011）.Increasing area and habitat promote species richness（Triantis et al,2003）and both these mechanisms have

Amphibians and Reptiles of Cebu,Philippines：The Poorly Understood Herpetofauna of an Island with Very Little Remaining Natural Habitat

Despite its proximity to other well studied islands, Cebu has received little attention from herpetologists, most likely because of early deforestation and the perception very little natural habitat remains for amphibians and reptiles. In this study, we present a preliminary assessment of island＇s herpetofauna, focusing our field work on Cebu＇s last remaining forest fragments and synthesizing all available historical museum distribution data. We surveyed amphibians and reptile populations using standardized methods to allow for comparisons between sites and assess sufficiency of sampling effort. Fieldwork resulted in a total of 27 species recorded from five study sites, complementing the 58 species previously known from the island. Together, our data and historical museum records increase the known number of Cebu＇s resident species to 13 amphibians（frogs） and 63 reptiles（lizards, snakes, turtle, crocodile）. We recorded the continued persistence Cebu＇s rare and endemic lizard（Brachymeles cebuensis） and secretive snakes such as Malayotyphlops hypogius, and Ramphotyhlops cumingii, which persist despite Cebu＇s long history of widespread and continuous habitat degradation. Most species encountered, including common and widespread taxa, appeared to persist at low population abundances. To facilitate the immediate recovery of the remaining forest fragments, and resident herpetofauna, conservation effort must be sustained. However, prior to any conservation interventions, ecological baselines must be established to inform the process of recovery.

Bird community patterns in response to the island features of urban woodlots in eastern China

Many studies have demonstrated the changes in the spatial patterns of plant and animal communities with respect to habitat fragmentation.Insular communities tend to exhibit some special patterns in connection with the characteristics of island habitats.In this paper,the relationships between richness,assemblage,and abundance of bird communities with respect to island features were analyzed in 20 urban woodlots in Hangzhou,China.Field investigations of bird communities,using the line transect method,were conducted from January to December,1997.Each woodlot was surveyed 16 times during the year.Results indicated that bird richness was higher,per unit area,in the smaller woodlots than the larger ones,and overall bird density decreased with the increase in the size of woodlot.However,the evenness of species abundance increased with the area,and small woodlots were usually dominated by higher density species and large woodlots by medium density species.Most species occurring in the small woodlots also occurred in larger woodlots.Also,bird communities among urban woodlots showed a nestedness pattern in assemblage.These patterns implied that the main impacts of woodland habitat fragmentation are:(1)species are constricted and thus species number will increase at a given sample size;(2)as surface area decreases,the proportion of forest edge species as to interior species will increase;(3)community abundance will therefore increase per unit area but most individuals will be from a few dominant species;and(4)overall species diversity will decrease at a habitat level as well as at a region level.These patterns of community in response to the island features were therefore summarized as“island effects in community”.The underlying processes of such observations were also examined in this paper.Woodlot area,edge ratio,isolation,and habitat nestedness were considered as the important factors forming the island effects in community.High heterogeneity between habitats usually contributed most to the maintenance of regional biodiversity,especially in urban woodlots.