Detangling the Effects of Environmental Filtering and Dispersal Limitation on Aggregated Distributions of Tree and Shrub Species: Life Stage Matters.

The pervasive pattern of aggregated tree distributions in natural communities is commonly explained by the joint effect of two clustering processes: environmental filtering and dispersal limitation, yet little consensus remains on the relative importance of the two clustering processes on tree aggregations. Different life stages of examined species were thought to be one possible explanation of this disagreement, because the effect of environmental filtering and dispersal limitation are expected to increase and decrease with tree life stages, respectively. However, few studies have explicitly tested these expectations.

[Topographic distribution patterns of forest gap within an evergreen broad-leaved forest in Tiantong region of Zhejiang Province, Eastern China].

To explore the effects of multi-dimensional topographic factors on forest gap distribution, the forest gaps in a 20 hm2 dynamic monitoring plot of an evergreen broad-leaved forest in Tiantong region of Zhejiang were taken as the objects to study the distribution patterns of the gap fraction, gap density, and gap area under the effects of altitude, slope degree, slope shape, slope aspect, and slope position by using a geographic information system (GIS) software. In the plot, the gap fraction was 13.1% , gap density was 9.

[Spatial heterogeneity of soil properties and its relationships with terrain factors in broad-leaved forest in Tiantong of Zhejiang Province, East China].

By using geostatistical methods, this paper studied the spatial heterogeneity and distribution patterns of soil pH, total carbon, total nitrogen, and total phosphorus in an evergreen broad-leaved forest in Tiantong of Zhejiang Province, and the effects of terrain factors (elevation, convexity, and slope) on the soil properties were quantified based on RDA ordination and partial regression analysis. The coefficient of variation for the soil pH, total carbon, total nitrogen, and total phosphorus was 5.18%, 42.