江西官山长柄双花木灌丛的群落特征与多样性

采用植物群落学的研究方法，对江西官山自然保护区长柄双花木灌丛群落特征及多样性进行了研究。结果表明，群落结构特征为单优势种群落，乔木层种类少，树冠不连续，灌木层以长柄双花木占绝对优势，林下更新较差。群落的物种多样性指数低，表明生境条件特殊，群落结构不稳定。     

修文石灰岩山地篦子三尖杉灌丛群落多样性研究

根据样方调查,对分布在黔中地区修文县六桶乡的篦子三尖杉群落的种类组成、外貌、结构特征和物种多样性进行分析.结果表明,在800m2的样地中,有维管植物92种,隶属52科79属.群落中乔木的个体数量很少,主要由灌木和草本组成,灌木层主要优势种为篦子三尖杉、火棘等.群落外貌常绿,结构简单.整个群落的物种丰富度Gleason指...     

Impacts of overgrazing and reclamation on soil resources in rangeland ecosystems in Huailai Basin, Heibei, China

The soil constituents and relations between the variation of soil resources and plant communities in three adjacent sites representing the overgrazing, reclamation and comparatively undusturbed communities respectively were quantified and examined in study are in Huailai Basin, Hebei Province, China. There have been significantly greater constituent of C, N, P in the soils of shrubland site. C_org, N_total, N_avail and P_aval were between 1. 18 and 3. 90 times more concentrated in the soils of shrubland site in comparison with the other two sites. Although the P_total concentration was lower in shrubland soils than in overgrazed rangeland soils, the P_avail concentration, however, was significantly greater in the soils of shrubland site comparing to those in the soils of rangeland and millet field sites. Among the three sites, CV exceeding 40% were found for SO₄, Cl, and F ion. The CV of organic carbon also exceeded 40% but only in the soils of millet field site. The highest CV were found for F, SO₄, ion in the soils of shrubland and overgrazed rangeland sites, while for Cl and SO₄ ion in those of millet field site. The results also showed that the introductions of shrubs are of vital importance for the accumulation of soil nutrients and maintenance of soil fertilities, and also for the restoration and reconstruction of deseritified ecosystems. Foundation item: Supported by the ‘973’ Project of Ministry of Science and Technology of China (G2000018607) Biography: ZHANG Hong (1961-), male, Ph. D. Professor, research direction: restoration ecology for degraded ecosystem.     

贺兰山西坡植物多样性研究

研究了贺兰山西坡浅山带植物多样性特征.结果表明,不同植被带的植物多样性明显不同,荒漠灌丛带的物种丰富度、多样性和均匀度指数均随海拔的升高而增加;荒漠草原带的物种丰富度随海拔的升高呈现先增加而后降低的特点,其多样性和均匀度则随海拔的升高呈现先降低而后增加的趋势;疏林灌丛带的丰富度、多样性和均匀度指数随海拔的升高先增加而后基本保持不变.     

Impacts of Overgrazing and Reclamation on Soil Resources in Rangeland Ecosystems in Huailai Basin, Hebei, China

The soil constituents and relations between the variation of soil resources and plant communities in three adjacent sites representing the overgrazing, reclamation and comparatively undisturbed communities respectively were quantified and examined in study area in Huailal Basin, Hebei Province, China. There have been significantly greater constituent of C, N, P in the soilsof shrubland site. Corg, Ntotal, Navail and Pavail were between 1.18 and 3.90 times more concentrated in the soils of shrubland site in comparison with the other two sites. Although the Ptotal concentration was lower in shrubland soils than inovergrazed rangeland soils, the Parval concentration, however, was significantly greater in the soils of shrubland site, and increased by 59. 1% and even 289.6% in the soils of shrubland site comparing to those in the soils of rangeland and millet field sites. Among the three sites, CV exceeding 40% werefound for SO4 , Cl, and F ion. The CV of organic carbon also exceeded 40% but only in the soils of millet field site. The highest CV were found for F, SO4 ion in the soils of shrubland and overgrazed rangeland sites, while for Cl and SO4 ion in those of millet field site. The results also showed that the introductions of shrubs are of vital importance for the accumulation of soil nutrients and maintenance of soil fertilities, and also for the restoration and reconstruction of desertified ecosystems.