We described potential changes in the geo- graphic distribution and occurrence probability of Pinus koraiensis Sieb. et Zucc. and Eleutherococcus senticosus （Rupr. et Maxim.） Maxim. in the counties of northeast China. This information was used to identify priority areas for protection and provide protection and management recommendations within each studied county. The two species were mapped in 2884 study plots throughout this region over a 4-year period （38°40＇N-53°30＇N, 115°05＇E- 135°02＇E）. We used the species distribution models （Maxent）, systematic conservation planning models （Marxan）, and Geographic Information Systems （ArcGIS 10.0）. The distributions of two species were correlated in the study area, enabling unique and economically viable joint conservation measures to be implemented. Three models were combined to identify feasible priority con- servation sites. We used local spatial statistics to assess all identified conservation areas in relation to potential climate change based shifts in the geographic distribution of the two species. Model-based conservation strategies were used to identify effective measures to protect and utilize these two tree species in the study region. This study pre- sents a novel technique for assessing wild plant distribu- tions, in addition to serving as a model for the conservation of other species within the framework of general forest management, ecological construction, and geographical surveying.
Jizhong WanChunjing WangJinghua YuSiming NieShijie HanJuzhao LiuYuangang ZuQinggui Wang
Reduction in vegetation cover caused by human activities has a great impact on soil temperature. It is important to assess how soil temperature responds to reduction of vegetation height and density. In this paper we first report the trends of mean annual soil surface and air temperatures recorded at the meteorological stations near the Ecological Research Station for Grassland Farming (ERSGF) from 1961 to 2007, then we setup an experiment using reed (Phragmites australis) stalks with different heights and densities to simulate effects of different vegetation height and density on soil and air temperatures. The warming rates of the mean annual soil and air temperatures were 0.043 and 0.041C a 1 , respectively. Changes of soil temperature were characterized by both increased mean annual maximum and minimum soil temperatures. At the experimental site, mean daily temperature, mean daily maximum soil and air temperatures increased significantly. In contrast, mean daily minimum soil temperature increased significantly while mean daily minimum air temperature decreased significantly as the height and density of reed stalks reduced during the experimental period. Mean diurnal soil temperature ranges were smaller than mean diurnal air temperature ranges. These results highlight that the importance of vegetation cover on soil and air temperatures.
SONG YanTaoZHOU DaoWeiZHANG HongXiangLI GuangDiJIN YingHuaLI Qiang
Aims Forest disturbance from extreme weather events due to climate change could increase the contribution of fresh green leaves to the litter layer of soil and subsequently alter the composition and activity of the soil microbial properties and soil carbon cycling.The objective of this study was to compare the effect of naturally fallen litter and fresh leaves on the soil microbial community composition and their activities.Methods Fresh leaves and normal fallen litter were collected from four tree species(Pinus elliottii,Schima superba,Acacia mangium,A.auriculaeformis)in subtropical China and mixed with soil.Soil microbial community composition was determined using PLFAs,and its activity was quantified by soil respiration.During a 12-month period,the decomposition rate of litter was measured bimonthly using a litterbag method.Soil microbial samples were collected after 6 and 12 months.Soil respiration was measured monthly.Important Findings We found that fresh leaves decomposed faster than their conspecific fallen litter.Although total microbial biomass and bacterial biomass were similar among treatments,soil fungal biomass was higher in fresh leaf than fallen litter treatments,resulting in greater values of the Fungal phospholipid fatty acids(PLFAs)/Bacterial PLFAs ratio.Fungal PLFA values were greater for Schima superba than the other species.The effect of litter type on soil respiration was species-dependent.Specifically,fallen litter released 35%more CO_(2) than fresh leaves of the conifer P.elliottii.The opposite pattern was observed in the broadleaf species whose fresh leaf treatments emitted 17%–32%more CO_(2) than fallen litter.Given future predictions that global climate change will cause more disturbances to forests,these results indicate that conifer and broadleaf forests in subtropical China may respond differently to increased fresh litter inputs,with net soil microbial respiration decreasing in conifer forests and increasing in broadleaf forests.
Faming WangJin LiuBi ZouDeborah A.NeherWeixing ZhuZhian Li
