东阿拉善—西鄂尔多斯地区特有濒危植物适生生境景观破碎化与优先保护序的相关分析

为了确定东阿拉善—西鄂尔多斯地区特有濒危植物适生生境的破碎化程度与优先保护序之间的关系,以东阿拉善—西鄂尔多斯地区特有濒危植物为研究对象,采用常规的样地调查方法,结合3S技术所获取的相关数据,对特有濒危植物景观粒度、景观破碎指数等指标进行定量计算,分析所得结果并与各物种的优先保护序进行比较,发现各物种适生生境景观破碎化的指标计算结果与物种的优先保护序之间存在着一定密切关系。结果表明,只要依据各物种在该区域的生物学性状与特征,选择适宜的景观破碎公式计算,完全能够准确反映该地区濒危植物的濒危程度。

帽儿山蕨类植物种群生态的研究

在深入调查研究的基础上 ,首次报道了帽儿山地区的蕨类植物资源 ,共计 1 3个科、2 3个属和 40多个种 ,根据各种群在生态上的不同要求 ,以表格的形式说明了主要蕨类种群对“湿度”和“光照”因子的适应关系。本文还着重指出了各种群的生物学特性和生态环境的一致性 。

Research Progress and Thoughts of Habitat Suitability Evaluation of Citrus Based on Niche Theory

[Objective] This study was to overview the research progress and thoughts of habitat suitability evaluation of citrus based on ecological niche theory. [Method] The research progress on habitat suitability evaluation and ecological niche theory to the niche selection of crops were comprehensively analyzed. [Result] The research thoughts of using niche theory to evaluate the habitat suitability of citrus with quality constraint were put forward, including collection and expression of citrus ecological environment and quality factors, interactive response study of the citrus ecological environment and quality, and habitat suitability evaluation and adaptation mechanism study of citrus based on quality constraint. [Conclusion] This study provided references for the development of citrus industrialization.

Physiological Adaptation of Habitat by Ion Distribution in the Leaves of Four Ecotypes of Reed (Phragmites australis)

The ion levels in the epidermal bulliform cells of epidermis, mesophyll cells and cells of the vascular bundle sheath of four ecotypes of reed (Phragmites australis (Cav.) Trin. ex Steud.) were determined by means of X_ray microanalysis. The results indicated that higher K +, Na +, Ca 2+ , Mg 2+ and Cl - were distributed in the vascular bundle sheath cells than in mesophyll cells and epidermal bulliform cells of the swamp ecotype. Higher Ca 2+ was found in the bulliform cells than in mesophyll cells and vascular bundle sheath cells, higher Mg 2+ in the mesophyll cells and higher K +, Na + and Cl - in the vascular bundle sheath cells of the dune ecotype. Higher Na + and Mg 2+ was determined in the mesophyll cells than in the bulliform cells and vascular bundle sheath cells, and higher K +, Ca 2+ and Cl - in the vascular bundle sheath cells of the light salt meadow ecotype. In the heavy salt meadow ecotype, higher Na + and Mg 2+ were accumulated in the bulliform cells than in mesophyll cells and vascular bundle sheath cells, but higher K +, Ca 2+ and Cl - in the mesophyll cells. Furthermore, the distributional conditions of the above five ions in leaf cells of the four ecotypes and their significance in the physiological adaptation of reed to habitat were discussed in detail.

Artificial woodland degradation in semi-arid agro-pastoral transitional area： conceptual model and status assessment

Planting trees was used as one of cost-effective measures for desertification control in add and semi-add areas of China. Woodland degradation, however, is becoming an inevitable issue in these areas. In this paper, a typical county, Ejin Holo County, Inner Mongolia, China was selected for its assessment of artificial woodland degradation. A conceptual model for woodland degradation was delineated qualitatively based on field sampling survey, and four model-based indicators as humidity index （HI）, vegetation index （NDVI）, soil type （ST） and soil erosion modulus （EM） were screened out and used to a GIS-based method for artificial woodland degradation assessment in this semi-add agro-pastoral transitional area. All the indicator layers were overlaid and desertification assessed using simplified equation with equal weights for each indicators. The assessment results showed that in 336. 09 km^2 of total woodland area, 311.35 km^2 woodland were under degradation, and the area for slight, medium, severe degradation was 78.97, 119.73 and 112.65 km^2, respectively. It was suggested that much attention should be paid on woodland improvement and plant species selection, especially shrub species, before revegetation in similar areas.

How will climate change affect the potential distribution of Eurasian tree sparrows Passer montanus in North America？

Habitat suitability models have been used to predict the present and future potential distribution of a variety of spe- cies. Eurasian tree sparrows Passer montanus, native to Eurasia, have established populations in other parts of the world. In North America, their current distribution is limited to a relatively small region around its original introduction to St. Louis, Missouri. We combined data from the Global Biodiversity Information Facility with current and future climate data to create habitat suitability models using Maxent for this species. Under projected climate change scenarios, our models show that the distribution and range of the Eurasian tree sparrow could increase as far as the Pacific Northwest and Newfoundland. This is potentially important in-formation for prioritizing the management and control of this non-native species [Current Zoology 57 （5）： 648--654, 2011].