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621.
Carlson PR Yarbro LA Madley K Arnold H Merello M Vanderbloemen L McRae G Durako MJ 《Environmental monitoring and assessment》2003,81(1-3):393-408
We examined the response of demographic, morphological, and chemical parameters of turtle grass (Thalassia testudinum), to much-higher-than-normal rainfall associated with an El Niño event in the winter of 1997–1998. Up to 20 inches of added rain fell between December 1997 and March 1998, triggering widespread and persistent phytoplankton blooms along the west coast of Florida. Water-column chlorophyll concentrations estimated from serial SeaWiFS imagery were much higher during the El Niño event than in the previous or following years, although the timing and magnitude of phytoplankton blooms varied among sites. Seagrass samples collected in 1997, 1998, and 1999 provided an excellent opportunity to test the responsiveness of Thalassia to decline and subsequent improvement of water quality and clarity in four estuaries. Using a scoring technique based on temporal responsiveness, spatial consistency, and statistical strength of indicators, we found that several morphological parameters (Thalassia shoot density, blade width, blade number, and shoot-specific leaf area) were responsive and consistent measures of light stress. Some morphological parameters, such as rhizome apex density, responded to declines and subsequent improvement in water clarity, but lacked the statistical discriminating power necessary to be useful indicators. However, rhizome sugar, starch, and the total carbohydrate concentrations also exhibited spatially and temporally consistent variation as well as statistical strength. Because changes in shoot density, as well as water clarity, affect rhizome carbohydrate levels, a composite metric based on Thalassia shoot density and rhizome carbohydrate levels together is probably more useful than either parameter alone as an indicator of seagrass health. 相似文献
622.
Jorge Ares Mónica Bertiller Alejandro Bisigato 《Environmental Modeling and Assessment》2003,8(1):1-13
We present a technique to quantify and model the intensity of structural changes produced by management of dry grazing lands at a landscape scale. The technique is illustrated with the analysis of digitized black–white (b/w) imagery and an application to the study of changes induced by grazing gradients. Structural changes in patchy vegetation canopies were studied in the Patagonian Monte (Chubut, Argentina) at two resolution scales by means of linear transects in the field (50 m) and others drawn on aerial b/w photographs (2–5 km) of grazed paddocks. Spatial series of plant cover values along transects in the field and on photographs were analyzed with standard techniques of spectral analyses, including auto-correlation spectra and Fourier transforms. In order to test the internal consistency of the techniques used, synthetic plant canopies with patches of varying cover and size were generated by means of a stochastic model of plant growth under different stocking rates or after varying periods of recovery. The behavior of the simulation model is consistent with the observed dynamics of plant canopies in semiarid environments. There is a consistent relation between the number and geometric properties of plant patches (patch number, patch size, patch connectivity) and the signal/noise ratios of the Fourier decomposition describing plant density data. Signal/noise ratios corresponding to plant cover data in paddocks with different grazing treatment are consistent with the assumptions derived from modeled canopies, as well as those estimated from optical density of b/w aerial photographs of paddocks. We tested the hypotheses that patch arrangements as quantified by the signal/noise ratios vary in accordance with grazing gradients in paddocks with a permanent corner-located watering point. The use of digitized b/w images allows inspecting permanent changes over time periods when other types of images were not yet available. 相似文献
623.
Criteria and Indicators of Sustainable Forest Management 总被引:2,自引:0,他引:2
Hall JP 《Environmental monitoring and assessment》2001,67(1-2):109-119
624.
Ariane de Bremond 《Ambio》2021,50(7):1299
This perspective recognizes the seminal Ambio articles of Sombroek et al. (1993), Turner et al. (1994) and Brussaard et al. (1997), identifying their individual and collective role in laying the ground work for a global change research agenda on land and its human use through increased understanding of terrestrial ecosystem dynamics and global change, and furthering nascent interdisciplinary efforts within the global change science community to better understand the ‘human driving forces’ of change. From these efforts, land system science, as a systemic science focused on complex socio-ecological interactions around land use and associated trade-offs and synergies, emerges as an ‘interdiscipline’ challenged to better understand land systems as the ‘meeting ground’ for multiple claims on land for biodiversity, carbon, livelihoods, food production among others, and support pathways to sustainability for people and nature. 相似文献
625.
规划环境影响评价指标体系及评价方法浅析 总被引:4,自引:0,他引:4
对规划环境影响评价的内容作出了概述性的介绍,并根据规划环境影响评价的特点,得出规划环境影响评价的指标体系应包括自然环境指标、生态环境指标、资源利用指标、能源利用指标和社会经济指标5大体系。列举了当前适用于规划环境影响评价的技术方法,并对其进行简单的对比分析。 相似文献
626.
N. Van Cauwenbergh K. Biala C. Bielders V. Brouckaert L. Franchois V. Garcia Cidad M. Hermy E. Mathijs B. Muys J. Reijnders X. Sauvenier J. Valckx M. Vanclooster B. Van der Veken E. Wauters A. Peeters 《Agriculture, ecosystems & environment》2007,120(2-4):229-242
Sustainable development and the definition of indicators to assess progress towards sustainability have become a high priority in scientific research and on policy agendas. In this paper, we propose a consistent and comprehensive framework of principles, criteria and indicators (PC&I) for sustainability assessment of agricultural systems, referred to as the Sustainability Assessment of Farming and the Environment (SAFE) framework. In addition we formulate consistent and objective approaches for indicator identification and selection. The framework is designed for three spatial levels: the parcel level, the farm level and a higher spatial level that can be the landscape, the region or the state. The SAFE framework is hierarchical as it is composed of principles, criteria, indicators and reference values in a structured way. Principles are related to the multiple functions of the agro-ecosystem, which go clearly beyond the production function alone. The multifunctional character of the agro-ecosystem encompasses the three pillars of sustainability: the environmental, economic and social pillars. Indicators and reference values are the end-products of the framework. They are the operational tools that are used for evaluating the sustainability of the agro-ecosystems. The proposed analytical framework is not intended to find a common solution for sustainability in agriculture as a whole, but to serve as an assessment tool for the identification, the development and the evaluation of agricultural production systems, techniques and policies. 相似文献
627.
Aysel?KarafistanEmail author Fatma?Arik-Colakoglu 《Mitigation and Adaptation Strategies for Global Change》2005,10(1):127-143
Manyas, also known as the Bird Paradise Lake, is situated near the south-eastern coasts of the Marmara Sea in Turkey. This shallow lake, is a unique natural reserve providing habitat for migratory birds with its rich fauna and plankton species. The objective of this work is to study the ecological and water quality changes resulting from increasing anthropogenic pollution and human intervention on the natural variations of the water level. For this purpose, physical, chemical and microbiological aspects of the aquatic ecosystem in the lake of Manyas are being measured semimonthly since more than a year. After the completion of field measurements associations between different parameters will be searched by means of a water quality model. Results obtained will be used in the sustainable restoration of the lake. In this paper, firstly the nutrient and trophic dynamics of the planktonic ecosystem are associated with the bio-geochemical water cycle in the lake. Secondly, space and time distributions of all physical, chemical and microbiological data are presented and interactions between the nutrient availability and some microscopic communities are discussed. 相似文献
628.
Krol Maarten Alcamo Joseph Leemans Rik 《Mitigation and Adaptation Strategies for Global Change》1997,1(4):341-361
Among the key issues of concern to the Climate Convention is the stabilization of greenhouse gas concentrations and the minimization
of impacts to global agriculture, natural ecosystems and economic development. The purpose of this paper is to couple these
issues in consistent, integrated scenarios, using the IMAGE 2.0 model as an integrating tool. Scenarios of gradual stabilization
of atmospheric CO2 at 350 and 450 ppm are compared to a baseline of no policy action in which CO2 concentration increases to 777 ppm. Under the stabilizaton scenarios substantially smaller areas of wheat and millet, as
well as nature reserves, are threatened by climate change, especially in temperate regions. The amount of sea level rise is
also reduced under the stabilization scenarios. However, climate continues to change under the stabilization scenarios and
therefore some ‘residual’ climate impacts occur. Hence the integrated scenarios indicate that stabilizing greenhouse gas concentrations
at or slightly above current levels will lessen impacts as compared to baseline levels, but not eliminate them.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
629.
A Method for Constructing a Social Vulnerability Index: An Application to Hurricane Storm Surges in a Developed Country 总被引:11,自引:1,他引:11
Lisa Rygel David O’sullivan Brent Yarnal 《Mitigation and Adaptation Strategies for Global Change》2006,11(3):741-764
An important goal of vulnerability assessment is to create an index of overall vulnerability from a suite of indicators. Constructing
a vulnerability index raises several problems in the aggregation of these indicators, including the decision of assigning
weights to them. The purpose of this paper is to demonstrate a method of aggregating vulnerability indicators that results
in a composite index of vulnerability, but that avoids the problems associated with assigning weights. The investigators apply
a technique based on Pareto ranking to a complex, developed socioeconomic landscape exposed to storm surges associated with
hurricanes. Indicators of social vulnerability to this hazard are developed and a principal components analysis is performed
on proxies for these indicators. Overall social vulnerability is calculated by applying Pareto ranking to these principal
components. The paper concludes that it is possible to construct an effective index of vulnerability without weighting the
individual vulnerability indicators. 相似文献
630.
真菌降解技术中载体固定和表面活性剂的作用 总被引:4,自引:0,他引:4
采用载体固定技术和加入表面活性剂的方法,以乙基橙和比布列希猩红为底物,建立黄孢原毛平霸菌-染料共培养体系。实验结果表明:聚乙烯泡沫小块和玻璃棉,可有效地固定菌体细胞,加速染料的脱色降解;在接种的同时加入0.1%~0.2%Tween80,能有效地保护降解酶的性;培养方式、菌团大小、培养体系的生理特性等,和解体系的反应效率均有明显的影响。采用本方法能克服动培养系统对真菌反应体系的破坏,乙基橙和比布列希 相似文献