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61.
62.
Len N. Gillman 《New Zealand geographer》2008,64(1):57-67
Abstract: There has been considerable international progress towards sustainable forest management (SFM) of temperate and boreal forest. However, the effectiveness of SFM legislation in providing for the protection of natural forest values has been largely undemonstrated. In this study, all the SFM Plans in the North Island, New Zealand, approved under the Forests Amendment Act (1993) are assessed. It is concluded that the requirements in the plans for assessing, monitoring and maintaining natural values are inadequate with the lack of public participation, and associated appeal rights over decisions, viewed as the key gap in the legislation. 相似文献
63.
EFFECTS OF HARVEST STAGE ON THE TOTAL LIPID AND FATTY ACID COMPOSITION OF FOUR CYLINDROTHECA STRAINS
INTRODUCTIONPeopleshowedgreatinterestsinmicroalgaeduetotheirgoodcharacteristics,suchashigheffi ciencyofusingsolarenergy,smallsize ,nutritionalvalue ,rapidgrowthandmultiplicationrate .Mi croalgaehaveanimportantroleinmaricultureasfoodforlarvalstagesofcrusta… 相似文献
64.
Kara L. Webster Jason A. Leach Paul W. Hazlett Robert L. Fleming Erik J. S. Emilson Daniel Houle Kara H. Y. Chan Fariborz Norouzian Amanda S. Cole Jason M. O'Brien Karen E. Smokorowski Stephanie A. Nelson Shelagh D. Yanni 《水文研究》2021,35(4):e14109
The Turkey Lakes Watershed (TLW) study is a federal, interdepartmental study established in 1979 to investigate the effects of acid rain on terrestrial and aquatic ecosystems. The 10.5 km2 watershed, located in the Eastern Temperate Mixed Forest on the Canadian Shield, has been the site of multidisciplinary studies on biogeochemical and ecological processes conducted across plot to catchment scales. The whole-ecosystem investigative approach was adopted from the outset and has allowed research to evolve from its original (and continuing) acidification focus to include investigations on the effects of climate change, forest harvesting and other forest ecosystem perturbations. The extensive scientific and support infrastructure allows for collection of a comprehensive data record essential for understanding long-term environmental trends. Data include atmospheric deposition, meteorology, stream hydrology and chemistry, soil, pore and ground water properties, understory and overstory vegetation, lake and outflow physical and chemical properties, and aquatic macroinvertebrate and fish community composition and abundance. These data have contributed to over 400 published research papers and graduate theses. The watershed has also figured prominently in many continent-wide comparisons advancing fundamental watershed theory. The knowledge gained at TLW has influenced pollutant emission and natural resource management policies provincially, nationally and internationally. 相似文献
65.
中国单季稻种植北界的初步研究 总被引:1,自引:2,他引:1
确定单季稻种植北界可为调整单季稻生产布局和科学应对气候变化提供依据.基于中国单季稻种植区地理分布及其主导气候因子,结合最大熵模型,研究了雨养(水热共同作用)与灌溉(热量限制)条件下中国单季稻种植区的北界,并与已有方法确定的中国单季稻北界进行了对比验证.结果表明:雨养条件下,中国单季稻种植北界可达黑龙江漠河县北部,沿漠河—塔河—呼玛中部以西的大兴安岭地区及龙江—泰来—杜尔伯特—大庆—肇州—肇源以西的地区不适合种植水稻;灌溉条件下中国单季稻种植的北界则不存在,即在中国最北部的漠河地区仍可种植单季稻,沿漠河—塔河—呼玛中部的水稻种植界限往西略有偏移.本研究确定的中国单季稻种植北界与当前单季稻种植北界更为接近,明显优于已有方法确定的单季稻种植北界. 相似文献
66.
We adapted Newton's law of cooling to model downstream water temperature change in response to stream‐adjacent forest harvest on small and medium streams (average 327 ha in size) throughout the Oregon Coast Range, USA. The model requires measured stream gradient, width, depth and upstream control reach temperatures as inputs and contains two free parameters, which were determined by fitting the model to measured stream temperature data. This model reproduces the measured downstream temperature responses to within 0.4 °C for 15 of the 16 streams studied and provides insight into the physical sources of site‐to‐site variation among those responses. We also use the model to examine how the pre‐harvest to post‐harvest change in daily maximum stream temperature depends on distance from the harvest reach. The model suggests that the pre‐harvest to post‐harvest temperature change approximately 300 m downstream of the harvest will range from roughly 82% to less than 1% of that temperature change that occurred within the harvest reach, depending primarily on the downstream width, depth and gradient. Using study‐averaged values for these channel characteristics, the model suggests that for a stream representative of those in the study, the temperature change approximately 300 m downstream of the harvest will be 56% of the temperature change that occurred within the harvest reach. This adapted Newton's law of cooling procedure represents a highly practical means for predicting stream temperature behaviour downstream of timber harvests relative to conventional heat budget approaches and is informative of the dominant processes affecting stream temperature. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
67.
胶州湾扇贝养殖对海域环境影响的初步研究 总被引:5,自引:0,他引:5
在2004年11月17日对胶州湾西部扇贝养殖区及周围海区进行的综合海洋环境调查的基础上,分析了胶州湾秋季扇贝养殖区与非养殖区的海洋环境状况,初步探讨了扇贝养殖在收获期对养殖区环境的影响。胶州湾养殖区表层水中COD和无机营养盐含量,除了NO2 -N的变化不明显外,均高于非养殖区的值。养殖区底层水中溶解氧含量和表层沉积物中硫化物的含量均明显超标。因此,肢州湾的扇贝养殖在收获期对环境的影响也是综合性的,且养殖海域的环境同时受陆源、水动力状况及养殖活动的综合影响。 相似文献
68.
EFFECTS OF HARVEST STAGE ON THE TOTAL LIPID AND FATTY ACID COMPOSITION OF FOUR CYLINDROTHECA STRAINS 总被引:1,自引:0,他引:1
Four strains of Cylindrotheca (B156, B164, B196, and B200) were harvested at three phases in the growth curve and their total lipid and fatty acid composition were determined. Total lipid reached highest values in the late stationary phase in B156 (24.0%), B164 (26.6%) and B200 (17.3%), in the exponential phase in B196 (15.5%). Saturated fatty acids increased with the devel-opment of the culture in B156 and B196, and reached their highest values in the late stationary phase in B156 (41.7%) and B196 (45.1%), in the early stationary phase in B164 (45.4%) and B200 (37.6%). Monounsaturated fatty acids increased with the development of the culture in B196 and B200, and reached their highest values in the late stationary phase in B196 (32.4%) and B200 (32.8%), in the early stationary phase in B164 (31.0%) and in the exponential phase in B156 (29.3%). Polyunsaturat-ed fatty acids decreased in the later phases of the culture in B164, B196 and B200, and peaked in theexponential phase in B164 (29.5%), B196 (42.9%) and B200 (37.3%), and in the early stationary phase in B156 (32.0%). 相似文献
69.
70.
2020年9—11月贵州省出现了1961年以来持续时间和影响范围最强的秋绵雨天气,1149站(总数的75.0%)出现特重级秋绵雨。秋绵雨天气造成秋收进度缓慢、秋种进度受阻,同时也不利于水果成熟采摘上市,2020年水稻单产较上年减产1.9%。针对该次秋绵雨天气过程,贵州省山地环境气候研究所及时启动应急保障服务,修正秋收及秋种气象适宜度等级指标,建立6 h、12 h、24 h秋收(抢收)气象适宜度指标,提前预警、及时发布秋收气象适宜度等级,滚动跟进服务,采用多种手段对外发布各种预报、预警信息,减少损失,保障贵州省水稻收获、颗粒归仓以及秋播顺利进行。 相似文献