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181.
JOACHIM CLAUDET JOSÉ ANTONIO GARCÍA‐CHARTON PHILIPPE LENFANT 《Conservation biology》2011,25(1):105-114
Abstract: The links between species–environment relations and species’ responses to protection are unclear, but the objectives of marine protected areas (MPAs) are most likely to be achieved when those relations are known and inform MPA design. The components of a species’ habitat vary with the spatial resolution of the area considered. We characterized areas at two resolutions: 250 m2 (transect) and approximately 30,000 m2 (seascape). We considered three categories of environmental variables: substrate type, bottom complexity, and depth. We sought to determine at which resolution habitat characteristics were a better predictor of abundance and species composition of fishes and whether the relations with environmental variables at either resolution affected species’ responses to protection. Habitat features accounted for a larger proportion of spatial variation in species composition and abundances than differences in protection status. This spatial variation was explained best by habitat characteristics at the seascape level than at the transect level. Species’ responses to protected areas were specific to particular seascape characteristics, primarily depth, and bottom complexity. Our method may be useful for prioritizing marine areas for protection, designing MPAs, and monitoring their effectiveness. It identified areas that provided natural shelter, areas acting as buffer zones, and areas where fish species were most responsive to protection. The identification of such areas is necessary for cost‐effective establishment and monitoring of MPAs. 相似文献
182.
政和—大埔断裂带经历多期复杂的构造变形变质作用,不同地段的时空演化特征有所差异,总体上可划分为四个演化阶段。即:①前加里东期(?)—加里东期韧性剪切变形变质作用(D_1),发生于中、下地壳,是顺层剪切(固态流变)的结果,为纯韧性变形,②印支期韧性剪切变形变质作用(D_2)——政和—大埔断裂的形成,以平移型剪切为主,形成S——C糜棱岩,为半韧性变形环境;③印支末期—燕山早期逆冲—推覆作用(D_3),为多层次逆冲推覆,东部所谓的“天窗”部分为这一时期逆冲岩片的残留体,随着早燕山期花岗岩的侵入逐渐过渡到伸展拆离环境,同时西部推覆体后缘出现拉张,形成有限的火山岩盆地,为半脆性—脆性变形环境;④燕山期(—喜山期)伸展—拆离作用(D_4),在相对年轻的拆离断层之下出露变质核杂岩(如稻香组和熊山岩体),并形成裂陷盆地堆积(梨山组),东部部分“天窗”属这类成因,形成环境跨度大,为半韧性→半脆性→脆性。 相似文献
183.
污染物质在包气带中运移规律的实验研究 总被引:6,自引:0,他引:6
通过室内淋滤实验,研究了酚,氰,砷,汞,铬在粉质轻亚粘土和中砂中的积累,运移规律:(1)土体对污染物质吸附净化均可分为强吸附阶段,饱和吸附阶段和吸附饱和阶段;(2)土体对污染物质的吸附净化强度与其粒度通常呈负相关;(3)酚,氰在包气带中降解的主要原因是自身的挥发性与生物分解作用。证实污染物质在包气带中的主要迁移形式为:H3AsO3,H2AsO3^-,CrO4^2,Hg(OH)^+,GgOHCL,同 相似文献
184.
生物炭作为一种新型环保材料常被用于改良土壤和污染修复,生物炭输入对土壤中营养元素的有效态会产生明显影响.本文基于太湖滨岸带不同土地利用类型(林地、草地、耕地和荒地),对比研究生物炭施加对不同类型土壤中营养元素有效态含量的影响,并探讨其动力学变化规律.结果表明,生物炭施加能够明显影响滨岸带土壤营养元素有效态含量,但对碳氮磷的影响效果存在差别.添加生物炭之后,土壤中溶解性有机碳呈显著下降趋势,而有效氮轻微增加,有效磷则明显增加.林地、草地、耕地和荒地土壤中溶解性有机碳含量分别下降了33. 3%、27. 4%、29. 5%和51. 4%;有效氮含量分别提高了10. 8%、18. 2%、16. 4%和15. 2%;有效磷含量分别增加了40. 0%、50. 2%、34. 0%和43. 6%.对比控制组(CK)和添加组(BC)的变化,土壤溶解性有机碳和有效磷含量在两组之间差别不大,而有效氮的含量变化差距较大,且在4种利用类型土壤中,生物炭施加后对不同营养元素有效态的影响程度有所差异. 相似文献
185.
186.
以新的国土空间规划语境为背景,基于核密度估计、标准差椭圆法和分类统计对我国2006—2018年省级以上开发区的密度分布特征变化、发展重心轴向的变化和主体功能区视角下的分布变化做了分析。研究表明:该阶段我国省级以上开发区空间分布的东西差距得到一定缓解,仍存在东部连片集聚、西部据点集中的模式差异。开发区分布的总体重心已经向西北方向移动,发展轴向则由原来的南北轴向转向了东南—西北轴向。从主体功能区视角来看,开发区空间分布格局呈现出外围扩散与局部缩减的动态调整。开发区规模的增长主要集中在重点开发区域,缩减主要发生在生态功能区域。这些新变化将为我国国土空间土地利用优化和国土空间管控实践提供重要参考。 相似文献
187.
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
188.
Stream Invertebrate Communities, Water Quality, and Land-Use Patterns in an Agricultural Drainage Basin of Northeastern Nebraska, USA 总被引:2,自引:0,他引:2
We used invertebrate bioassessment, habitat analysis, geographic information system analysis of land use, and water chemistry
monitoring to evaluate tributaries of a degraded northeast Nebraska, USA, reservoir. Bimonthly invertebrate collections and
monthly water chemistry samples were collected for two years on six stream reaches to identify sources contributing to reservoir
degradation and test suitability of standard rapid bioassessment methods in this region. A composite biotic index composed
of seven commonly used metrics was effective for distinguishing between differentially impacted sites and responded to a variety
of disturbances. Individual metrics varied greatly in precision and ability to discriminate between relatively impacted and
unimpacted stream reaches. A modified Hilsenhoff index showed the highest precision (reference site CV = 0.08) but was least
effective at discriminating among sites. Percent dominance and the EPT (number of Ephemeroptera, Plecoptera, and Trichoptera
taxa) metrics were most effective at discriminating between sites and exhibited intermediate precision. A trend of higher
biotic integrity during summer was evident, indicating seasonal corrections should differ from other regions. Poor correlations
were evident between water chemistry variables and bioassessment results. However, land-use factors, particularly within 18-m
riparian zones, were correlated with bioassessment scores. For example, there was a strong negative correlation between percentage
of rangeland in 18-m riparian zones and percentage of dominance in streams (r
2
= 0.90, P < 0.01). Results demonstrate that standard rapid bioassessment methods, with some modifications, are effective for use in this agricultural
region of the Great Plains and that riparian land use may be the best predictor of stream biotic integrity. 相似文献
189.
In this study, we measure effective diffusion coefficients for trichloroethene in undisturbed soil samples taken from Picatinny Arsenal, New Jersey. The measured effective diffusion coefficients ranged from 0.0053 to 0.0609 cm2/s over a range of air-filled porosity of 0.23-0.49. The experimental data were compared to several previously published relations that predict diffusion coefficients as a function of air-filled porosity and porosity. A multiple linear regression analysis was developed to determine if a modification of the exponents in Millington's [Science 130 (1959) 100] relation would better fit the experimental data. The literature relations appeared to generally underpredict the effective diffusion coefficient for the soil cores studied in this work. Inclusion of a particle-size distribution parameter, d10, did not significantly improve the fit of the linear regression equation. The effective diffusion coefficient and porosity data were used to recalculate estimates of diffusive flux through the subsurface made in a previous study performed at the field site. It was determined that the method of calculation used in the previous study resulted in an underprediction of diffusive flux from the subsurface. We conclude that although Millington's [Science 130 (1959) 100] relation works well to predict effective diffusion coefficients in homogeneous soils with relatively uniform particle-size distributions, it may be inaccurate for many natural soils with heterogeneous structure and/or non-uniform particle-size distributions. 相似文献
190.
Almost half (354) of all fish kills (805) in South Carolina, USA, between 1978 and 1988 occurred in the coastal zone. These
kills were analyzed for causative, spatial, and temporal associations as a distinct data set and as one integrated with ambient
water quality monitoring data. Estuarine kills as a result of natural causes accounted for 42.8% followed by man-induced (35.1%)
and undetermined causes (22.1%).
Although general pesticide usage was responsible for 53.9% of man-induced kills, weed control activities around resorts and
municipal areas accounted for slightly more kills (20.9%) than did agricultural (19.8%) or vector control (13.2%) uses. A
dramatic decline in agricultural-related kills has been observed since 1986 as the integrated pest management approach was
adopted by many farmers. When taken with the few kills (12.0%) resulting from wastewaters, this suggests that these two land-use
activities have been successfully managed via existing programs (IPM and NPDES, respectively) to minimize their contributions
to estuarine fish kills.
Ambient trend monitoring data demonstrated no coastal-wide dispersion of pesticide pollution. These data confirmed the nature
of fish kills to be site-specific, near-field events most closely associated with the contiguous land-use practices and intensities.
Typically, fish kill data are considered as event-specific data limited to the bounds of that event only. Our analysis has
shown, however, that a long-term data set, when integrated with ambient water quality data, can assist in regulatory and resource
management decisions for both short- and long-term planning and protection applications. 相似文献