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141.
A. P. Sizykh 《Russian Journal of Ecology》2007,38(4):234-237
As a result of monitoring spatial changes in the cenotic structure of plant communities at the taiga-extrazonal steppe boundary on the western coast of Lake Baikal, models of taiga-steppe communities reflecting the formation, dynamics, and genesis of forests in the taiga zone have been constructed. Changes in the species composition of communities, mesophytization of steppes, the expansion of moss synusiae characteristic of polydominant dark conifer and light conifer taiga forests, active forest invasion into steppe areas, and the presence of dark conifer tree species in light conifer forests have been revealed. 相似文献
142.
选取荒漠草原无林地的PM_(2.5)、PM_(10)浓度以及气象因子数据,对颗粒物浓度的时间变化特征及其与气象因子的关系进行分析。结果表明:(1)1月的PM_(2.5)、PM_(10)月平均浓度最高,7月的PM_(2.5)与PM_(10)达到最低。季节尺度上PM_(2.5)、PM_(10)浓度变化为由大到小顺序依次为冬季秋季春季夏季。(2)风速≤4.0 m/s时,随着风速增加,PM_(2.5)、PM_(10)浓度不断降低;当风速4.0 m/s时,PM_(2.5)、PM_(10)浓度随风速增加而增加。PM_(2.5)、PM_(10)浓度与温度负相关。相对湿度≤50%时,随着相对湿度增加,PM_(2.5)、PM_(10)浓度呈增加趋势;相对湿度50%时,随着空气湿度增加,PM_(2.5)、PM_(10)浓度呈降低趋势。随着大气气压上升,PM_(2.5)与PM_(10)浓度随之增加。(3)不同季节的气象因子对PM_(2.5)、PM_(10)影响存在差异。 相似文献
143.
基于RUE的不同草地类生态评价研究——以河西走廊为例 总被引:1,自引:1,他引:0
选择降水利用效率(RUE)作为评价指标,对河西走廊代表性草地类--温性荒漠、高寒草甸、温性草原进行生态评价研究。通过植被指数提取、降水Co-Kriging插值、图层叠加,得到河西走廊区域2006-2010年的RUE(NDVI)、RUE(PVI)、RUE(TSAVI)数据,并与地上生物量进行相关分析,筛选出适合不同草地类的RUE作为该区域生态评价的指标。结果表明:1)温性荒漠区RUE(PVI)与草地生物量风干重正相关性最高(R2=0.879),高寒草甸区RUE(NDVI)与草地生物量风干重的正相关性最高(R2=0.876),温性草原区RUE(TSAVI)与草地生物量风干重的正相关性最高(R2=0.895)。2)温性荒漠区、温性草原区生态均处于退化过程,高寒草甸区处于恢复过程。研究认为选择合适的RUE值可作为不同草地类生态评价指标,并具有理论的可行性和实践的可靠性。 相似文献
144.
145.
内蒙古乌兰布和沙漠旅游资源开发研究 总被引:1,自引:0,他引:1
旅游业对于开发区域丰富的资源及提高区域经济竞争力有着不可忽视的作用。沙漠是一种特殊的旅游资源,国际上沙漠旅游正成为一种新兴的旅游方式。积极开发沙漠旅游资源,既利于区域人地关系的和谐演进,又利于全面推进区域的可持续发展。以内蒙古乌兰布和沙漠旅游资源为研究对象,通过对沙漠中自然和人文资源的分析,探讨了沙漠旅游资源在开发利用中的优势和劣势。最后对乌兰布和沙漠旅游可持续发展的对策进行了探讨,并结合区情,提出了开发的具体措施,目的在于全面推进乌兰布和沙漠旅游业的发展。 相似文献
146.
/ Mechanized military maneuvers are an intensive form of disturbance to plant communities in large areas throughout the world. Tracking by heavy vehicles can cause direct mortality and indirectly affect plant communities through soil compaction and by altering competitive relationships. We assessed the long-term condition of structural attributes of open woodland, grassland, and shrubland communities at Fort Carson, Colorado, in relation to levels of disturbance and soil texture. Covariate analyses were used to help separate the directional forcings by the chronic disturbance from the regenerative capacities in order to assess the relative resistance and resilience of the communities and to determine whether the continual disturbance-recovery processes balanced under current levels of utilization. All three communities responded differently to disturbance. In open woodlands, altered understory/overstory relationships were suggested by increased grass, forb, shrub, and total vegetation cover and smaller decreases in shorter than taller woody species with increasing levels of disturbance. Grassland communities generally displayed greater responses to disturbance than other communities, but temporal dynamics were often similar, indicating relatively less resistance but greater resilience of this community. Weed and exotic species increased both temporally and in relation to levels of disturbance in all three community types. Temporal trends in community-level indices of dissimilarity and diversity also indicate that rates of disturbance were greater than rates of recovery. Few variables were related to within-community differences in soil texture. While total aerial cover was temporally stable, changes in species composition and in basal cover in grasslands and shrublands suggest increasing erosion potential. 相似文献
147.
Matveev N. M. Divnova M. A. Bazhanova A. V. Lobanova A. V. 《Russian Journal of Ecology》2004,35(4):220-224
The results of field studies at the Krasnosamarskii Station of Samara State University (the Samara River valley, the subzone of herb–sheep's fescue–feather grass steppes on ordinary chernozem) have shown that the age structure, ecological density, age index, and regeneration capacity of green strawberry cenopopulations depend on the trophic level and moisture content of soil and on the shading and mulching action of litter. 相似文献
148.
E. Jamie Trammell J. Scott Thomas Dave Mouat Quinn Korbulic Scott Bassett 《Journal of Environmental Planning and Management》2018,61(1):64-85
Scenario planning is an effective approach for examining possible futures by exploring the implications and consequences of different policy responses to landscape stressors. We present here a case study that explores plausible futures of urban growth in Southern Nevada, USA that illustrates how scenario analysis can be used to inform region-wide resource management by spatially modeling drivers of change, resource impacts, and potential policy responses. Using a suite of energy, water and biodiversity impact models, we assess the outcomes of the various futures on priority resources, resulting in a clear basis of comparison between alternative policies and their potential outcomes. This case study demonstrates the utility of scenario modeling for natural resource management by exploring crucial policy decisions that might be made in the near-term that could have lasting and sometimes conflicting influences on regional resources over the long term. 相似文献
149.
甘肃河西荒漠能源植物资源利用与产业化研究 总被引:1,自引:0,他引:1
从生物质能源开发利用意义开始,对河西地区的自然资源现状做了调查及分析,并对河西地区实施荒漠能源产业进行研究。分析了河西地区的自然环境特征、区域现状和人类不合理活动等多种因素作用下,自然资源出现的一系列问题;针对各类生态系统中存在的问题,提出了科学、合理的发展荒漠能源产业的对策建议。 相似文献
150.