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1.
在系统分析与初期实施的基础上,通过计算机仿真技术对后期~2010年提出进一步综合开发治理规划,并对规划实施的支撑条件进行了研究,这些研究丘陵农村的发展提供了具有参考意义的信息资料。 相似文献
2.
关于生态用水研究的讨论 总被引:25,自引:2,他引:25
十几年生态用水研究进展,其概念从自然地理平衡说法到生态系统稳定说法,至今未明确统一。按生态用水概念的内涵,将生态、环境、生态环境与用水、需水、耗水6个词的多样组合归纳为生态需水和生态用水两个词。地带性植被生态用水是生态用水研究的基础,可为生态保护和植被建设提供依据和目标。建议生态用水概念定义为:维持各类生态系统正常发育与相对稳定所必需消耗和现存的水称为生态用水。 相似文献
3.
探讨了“乡村聚落”和“乡村聚落生态系统”等基本概念以及乡村聚落生态研究的主要内容 ,包括乡村聚落生态评价和生态区划、对特殊聚落的研究、乡村聚落的选址以及乡村聚落生态与生态村建设 ,以期推动乡村聚落生态研究的发展。 相似文献
4.
合肥城市绿地系统的景观生态评价 总被引:1,自引:0,他引:1
城市绿地作为城市结构中的自然生产力主体,在城市生态系统中起着重要的作用。为科学合理地评价合肥城市绿地系统的景观生态现状,建立较为全面、科学的评价指标体系,运用景观生态学的原理和方法,选取多样性指数、均匀度指数、破碎度指数、分离度指数、分维度指数、连通性指数等8个景观指数对合肥市城市绿地系统的景观格局进行研究和分析。研究结果表明,合肥市城市绿地生态格局总体上较好,绿地率和人均公园绿地面积较高;但也存在绿地分布不均,各种类型相差较大,破碎度较高,多样性程度不高,分形维数指数偏低,绿地景观的自然性和复杂性不够,连通度较低等问题。针对存在的问题,提出了合肥城市绿地景观生态规划的优化建议。研究结果为合肥 相似文献
5.
Eric C. Merten Nathaniel A. Hemstad Randall K. Kolka Raymond M. Newman Elon S. Verry Bruce Vondracek 《Journal of the American Water Resources Association》2010,46(4):733-743
Merten, Eric C., Nathaniel A. Hemstad, Randall K. Kolka, Raymond M. Newman, Elon S. Verry, and Bruce Vondracek, 2010. Recovery of Sediment Characteristics in Moraine, Headwater Streams of Northern Minnesota After Forest Harvest. Journal of the American Water Resources Association (JAWRA) 46(4): 733-743. DOI: 10.1111/j.1752-1688.2010.00445.x Abstract: We investigated the recovery of sediment characteristics in four moraine, headwater streams in north-central Minnesota after forest harvest. We examined changes in fine sediment levels from 1997 (preharvest) to 2007 (10 years postharvest) at study plots with upland clear felling and riparian thinning, using canopy cover, proportion of unstable banks, surficial fine substrates, residual pool depth, and streambed depth of refusal as response variables. Basin-scale year effects were significant (p < 0.001) for all responses when evaluated by repeated-measures ANOVAs. Throughout the study area, unstable banks increased for several years postharvest, coinciding with an increase in windthrow and fine sediment. Increased unstable banks may have been caused by forest harvest equipment, increased windthrow and exposure of rootwads, or increased discharge and bank scour. Fine sediment in the channels did not recover by summer 2007, even though canopy cover and unstable banks had returned to 1997 levels. After several storm events in fall 2007, 10 years after the initial sediment input, fine sediment was flushed from the channels and returned to 1997 levels. Although our study design did not discern the source of the initial sediment inputs (e.g., forest harvest, road crossings, other natural causes), we have shown that moraine, headwater streams can require an extended period (up to 10 years) and enabling event (e.g., high storm flows) to recover from large inputs of fine sediment. 相似文献
6.
Rasmi Patnaik Gopalsamy Poyyamoli 《Journal of Environmental Planning and Management》2015,58(6):976-996
Over the past few years, the eco-industrial park (EIP) concept has been emerging as a significant driving force for sustainable industrialisation. Accumulating evidence indicates that the transition of existing industries into eco-industrial networking through industrial ecology (IE) principles would provide an excellent opportunity for facilitating such innovative industrialisation. A SWOT analysis was carried out to identify the potential and constraints for the successful implementation of an eco-industrial park in the ecologically fragile coastal zone of Puducherry. The results indicated significant potential for EIP development with few challenges. The lessons learnt can be used to provide broad guidelines for facilitating EIP development in the Puducherry region and similar scenarios found elsewhere across the world, especially in developing countries. 相似文献
7.
This study quantifies the disruption of zooplankton population fluctuations in relation to two magnitudes of fire retardant contamination events using artificial ponds as model systems. Population time series were analysed using redundancy analysis where time was modelled with a principal coordinate of neighborhood matrices approach that identified relevant scales of fluctuation frequencies. Analyses of temporal coherence provided insight whether population fluctuations correlated with system intrinsic or extrinsic forces. Responses to stress were species-specific and context-dependant. Contamination changed temporal structure in some species. These alterations were associated with an increased intrinsic control of dynamics. In some cases the magnitude of impact was unrelated to contamination severity. Some populations were less tolerant of pollution in the low relative to the high concentration treatment. Results suggest that population-level monitoring of degraded sites may be suboptimal because disparate population responses complicate the selection of specific sentinel organisms to monitor stress. 相似文献
8.
9.
Skiff Lobaugh Frank Farrow Xiuhong Feng Andrew Ogram 《Journal of environmental science and health. Part. B》2013,48(3):459-471
Abstract The effects of the herbicide triclopyr (3,5,6‐trichloro‐2‐pyridinyloxyacetic acid) on the mineralization of 2,4‐D (2,4‐dichlorophenoyxacetic acid) in two soils which differed in their histories of prior exposure to the two herbicides were investigated. The relative effects of triclopyr on 2,4‐D mineralization and most probable numbers of 2,4‐D degraders were dependent upon the soil. Triclopyr was shown to increase 2,4‐D mineralization rates in a soil which had been exposed to both 2,4‐D and triclopyr, but decreased the mineralization rate of 2,4‐D and inhibited the increase of most probable numbers of 2,4‐D degraders in a soil that had not been directly exposed to either herbicide. 相似文献
10.
Effects of glyphosate and foliar amendments on activity of microorganisms in the soybean rhizosphere
Nathan E. Means Robert J. Kremer Clifford Ramsier 《Journal of environmental science and health. Part. B》2013,48(2):125-132
A field study was conducted to determine the effects of glyphosate on microbial activity in the rhizosphere of glyphosate-resistant (GR) soybean and to evaluate interactions with foliar amendments. Glyphosate at 0.84 kg ae ha? 1 was applied GR soybean at the V4–V5 development stages. Check treatments included a conventional herbicide tank mix (2003 study only) and no herbicides (hand-weeded). Ten days after herbicide application, a commercially available biostimulant and a urea solution (21.0% N) were applied to soybean foliage at 33.5 mL ha? 1 and 9.2 kg ha? 1, respectively. Soil and plant samples were taken 0, 5, 10, 15, 20 and 25 days after herbicide application then assayed for enzyme and respiration activities. Soil respiration and enzyme activity increased with glyphosate and foliar amendment applications during the 2002 growing season; however, similar increases were not observed in 2003. Contrasting cumulative rainfall between 2002 and 2003 likely accounted for differences in soil microbial activities. Increases in soil microbial activity in 2002 suggest that adequate soil water and glyphosate application acted together to increase microbial activity. Our study suggests that general soil microbial properties including those involving C and N transformations are not sensitive enough to detect effects of glyphosate on rhizosphere microbial activity. Measurements of soil-plant-microbe relationships including specific microbial groups (i.e., root-associated Fusarium spp.) are likely better indicators of impacts of glyphosate on soil microbial ecology. 相似文献