[Changes in diversity of marsh plant communities under shrub encroachment in Sanjiang Plain and their soil control factors].

In this study, we explored the changes in plant community diversity and their relationship with soil factors under shrub encroachment pressure by selecting four marsh areas in Sanjiang Plain with different degrees of shrub cover (, 0≤≤100%), including marsh with no shrub encroachment (=0), light shrub encroachment (0<≤30%), medium shrub encroachment (30%<≤70%), and heavy shrub encroachment (70%<≤100%). The results showed that shrub encroachment was the main reason for the heterogeneity of plant community composition in marsh. With shrub encroachment, the dominant species was replaced by , whereas disappeared.

Building Virtual Watersheds: A Global Opportunity to Strengthen Resource Management and Conservation.

Modern land-use planning and conservation strategies at landscape to country scales worldwide require complete and accurate digital representations of river networks, encompassing all channels including the smallest headwaters. The digital river networks, integrated with widely available digital elevation models, also need to have analytical capabilities to support resource management and conservation, including attributing river segments with key stream and watershed data, characterizing topography to identify landforms, discretizing land uses at scales necessary to identify human-environment interactions, and connecting channels downstream and upstream, and to terrestrial environments. We investigate the completeness and analytical capabilities of national to regional scale digital river networks that are available in five countries: Canada, China, Russia, Spain, and United States using actual resource management and conservation projects involving 12 university, agency, and NGO organizations.

[Rainfall redistribution traits of three main forest types in Dagangshan Mountains of Jiangxi Province, China].

The redistribution processes of rainfall due to the canopy were studied on three typical forest types (Chinese fir forest, evergreen broad-leaved forest and Phyllostachys pubescens forest) in Dagangshan Mountains of Jiangxi Province. The results showed that from April to June, 2012, the total precipitation was 531.6 mm, with the maximum single rainfall of 61.

[Estimation of forest canopy closure by using partial least square regression].

Based on remote sensing and forest resources inventory data, this paper approached the feasibility of using Bootstrap approach to select optimal variables and using partial least square (PLS) regression to build a model for estimating forest canopy closure. The results showed that whether using a model built with all variables or a model with the optimal variables selected by Bootstrap approach, the relative deviation in estimating forest canopy closure was about 5%. The optimal variables selected in this paper differed greatly with those in the studies for other areas, suggesting that besides selection method, zonal vegetation and terrain could also induce the differences of selected optimal variables for the estimation of forest canopy closure.

[Distribution characteristics and seasonal dynamics of Cu and Zn in shrub-marsh plants in mountainous areas of northeast China].

The study on the distribution, accumulation, and seasonal dynamics of Cu and Zn in shrub-marsh plants Salix rosmarinifolia, Salix pentandra, Carex caespitosa and Carex schmidtii in mountainous areas of Northeast China showed that the Cu concentration in test plants varied from 6 to 12 mg x kg(-1), and its distribution was in the sequence of root > stem > leaf in S. rosmarinifolia and S. pentandra, and of stem > leaf > root in C.