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民勤沙区气候概况及其特点 总被引:1,自引:0,他引:1
民勤沙区气候干燥云量少,晴天多、光照丰富、有利于植物光合作用,辐射强,可作为能源。冬季漫长约半年,夏季短促炎热,昼夜温差大,在植物生长活跃期积温较高,平均可达3279.6℃。干燥少雨,为全国最干旱地区之一。植物生长期短,且在生长期内常有霜冻(旱、晚霜)危害,风多沙大,春季对植物苗期危害严重。 相似文献
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为探讨抗旱造林粉、BGA激活剂、ABT生根粉和浸根造林等抗旱技术对梭梭造林的影响,在民勤干旱沙区开展了有关应用技术研究.结果表明:(1)不同抗旱造林技术处理对造林林分保水作用存在一定的差异,BGA土壤激活剂使梭梭造林林分(100 cm)土壤含水率提高53.24%;(2)抗旱造林技术对梭梭的生长差异显著,BGA土壤激活剂处理的梭梭植株高相对对照处理增长5.32 cm,枝长增长2.81 cm; (3)抗旱造林技术对于提高梭梭造林成活率有促进作用.ABT生根粉、抗旱造林粉2种处理对于对照处理成活率分别提高8个百分点和6个百分点. 相似文献
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抗旱造林粉在民勤干旱沙区梭梭造林上的应用 总被引:2,自引:0,他引:2
2010年通过抗旱造林粉在民勤干旱沙区沙丘"双眉式"麦草方格沙障上进行梭梭裸根苗浸根法造林应用试验,结果表明:抗旱造林粉在民勤干旱沙区能提高造林成活率,可以提高植物体自身抗性,控制水分丧失,维持植物体水分平衡,延缓植物生命周期,抑制林木生长状态,降低造林成本,促进梭梭生长发育.因此,抗旱造林粉在干旱、半干旱地区应用已成... 相似文献
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民勤沙漠区气候特征的分析 总被引:9,自引:2,他引:7
民勤县位于甘肃河西走廊东北部荒漠区 ,地处巴丹吉林和腾格里2大沙漠的相壤地带 ,风沙危害严重。民勤沙漠区的气候特征是 :光热资源丰富 ,气温较差大 ,冬春季气温表现偏暖趋势 ;大风频繁 ,1年当中 ,大风主要分布在 3~ 5月份 ,在一昼夜之间主要分布在下午至傍晚 ;风向以西北风为主 ,≥ 6m/s的风速在 1 6个风向中 ,NW、WNW、W、NNW、N5个风向占 97 6 % ;降水稀少 ,且集中分布在 6~ 9月份。大面积沙漠裸露 ,是造成春季气温高 ,气压低 ,大风沙尘暴频繁的主要原因之一。节水、保护水资源和建造沙漠植被是改善当地生态环境的关键措施。 相似文献
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We examined 65 lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) sites in Alberta using a dendrochronological approach in order to examine the relationships between climate and growth of lodgepole pine across elevational ecoregions and diameter size classes. The 4 elevational ecoregions sampled included the Boreal Highlands (BH: 13 sites); the Foothills (FH: 36 sites); a grouping of the montane and subalpine zones of the southern Rocky Mountains (RM: 12 sites); and the montane zone of the Cypress Hills (CH: 4 sites). The first diameter size class was comprised of the three largest (top) diameter trees at each site. The tree list of each plot was ranked, then divided into three groups of equal basal area and the tree at the midpoint of each group (small, medium, and large) was selected for the other three size classes. Annual growth in basal area of lodgepole pine was generally sensitive to heat and moisture stress in late summer of the previous year, the degree of winter harshness, and the timing of the start of the growing season. Growth was inhibited by low temperature in all winter months at the most northern BH sites which had the coldest winters, but this effect was interrupted in some of the midwinter months in the more southerly sites in the RM, and we postulated this was due to the damaging influences of Chinook winds. Interannual growth patterns were strongly correlated between top diameter trees and the other classes, and trees of all diameter classes generally responded to climate in the same way, which indicated that it is sufficient to sample only the largest diameter trees in a stand to provide insight into growth–climate relationships. The forecasted growth estimates indicate that future climate warming will negatively impact the productivity of lodgepole pine in the FH, the heart of lodgepole distribution and productivity in Alberta. 相似文献
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By using the forest gap model-FAREAST, we simulated the effects of future climate change on forest composition and forest biomass of typical forests in northeastern China. We selected three different climate change scenarios, developed from GCMs results, of the ECHAM5-OM and HadCM3 models: the current climate, a warmer climate and a state of changing precipitation with higher temperatures. The results are as follows: if the climate does not change, the composition and forest biomass of the northeastern forests will retain their dynamic balance. A warmer climate is detrimental to the major forest types in the northeast. The percentage of major conifers is expected to decrease, along with a proportional increase of some broad-leafed species. The southern treeline of the mixed broad-leafed tree species/Korean pine forest in the temperate zone will tend to move northward. The warmer the climate, the more distinct the transition. If, furthermore, we were to take account of rainfall, the treeline in the northeast will tend to move northward. Rainfall seems to have little effect on the mixed broad-leafed tree species/Korean pine forests in the temperate zone. 相似文献
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在湖南省CO2排放与森林碳汇对比分析的基础上,根据湖南省生态公益林区划标准和湖南省生态区位重要性分析,对全省生态公益林面积需求量进行了测算。全省共测算生态公益林616.70万hm2,占全省林业用地总面积(1 293.29万hm2)的47.7%。 相似文献
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This paper examines how foresters have adapted to important supply and demand driven shocks in the last century that affected timber prices and forest investments. Many of the adaptations that foresters made to changing economic conditions will be the same types of adaptations that society will need foresters to make in the future in order to adapt to climate change. These include changing rotation ages to adapt to shifting disturbance conditions, increasing intensification of management in response to dwindling old growth stocks, movement of species across regions to find better growing conditions, among other things. The paper presents results of an integrated assessment of climate change impacts in forestry and shows how projected future changes for the next century are well within the historical context. 相似文献
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N. Kruchi 《Forest Pathology》1993,23(1):28-50
Review of literature indicates that many uncertainties and assumptions exist in predicting the impacts of a climate change on forest ecosystems. However, current knowledge is sufficient to encourage any measures that are combating climate change, that is to reduce first and foremost the release of harmful substances to the atmosphere, lithosphere and biosphere. 相似文献