The Interactive Effects of Fire and Diversity on Short-Term Responses of Ecosystem Processes in Experimental Mediterranean Grasslands

We conducted a field experiment using constructed communities to test whether species richness contributed to the maintenance of ecosystem processes under fire disturbance. We studied the effects of diversity components (i.e., species richness and species composition) upon productivity, structural traits of vegetation, decomposition rates, and soil nutrients between burnt and unburnt experimental Mediterranean grassland communities. Our results demonstrated that fire and species richness had interactive effects on aboveground biomass production and canopy structure components. Fire increased biomass production of the highest-richness communities. The effects of fire on aboveground biomass production at different levels of species richness were derived from changes in both vertical and horizontal canopy structure of the communities. The most species-rich communities appeared to be more resistant to fire in relation to species-poor ones, due to both compositional and richness effects. Interactive effects of fire and species richness were not important for belowground processes. Decomposition rates increased with species richness, related in part to increased levels of canopy structure traits. Fire increased soil nutrients and long-term decomposition rate. Our results provide evidence that composition within richness levels had often larger effects on the stability of aboveground ecosystem processes in the face of fire disturbance than species richness per se.     

Public Acceptance of Wildland Fire and Fuel Management: Panel Responses in Seven Locations

Wildland fire affects both public and private resources throughout the United States. A century of fire suppression has contributed to changing ecological conditions and accumulated fuel loads. Managers have used a variety of approaches to address these conditions and reduce the likelihood of wildland fires that may result in adverse ecological impacts and threaten communities. Public acceptance is a critical component of developing and implementing successful management programs. This study examines the factors that influence citizen support for agency fuel reduction treatments over time—particularly prescribed fire and mechanical vegetation removal. This paper presents findings from a longitudinal study examining resident beliefs and attitudes regarding fire management and fuels treatments in seven states: Arizona, Colorado, Oregon, Utah, Michigan, Minnesota, and Wisconsin. The study was implemented in two phases over a 6-year period using mail surveys to residents of communities adjacent to federal lands in each location. Questions replicated measures from the original project as well as some new items to allow a more in-depth analysis of key concepts. The study design enables comparisons over time as well as between locations. We also assess the factors that influence acceptance of both prescribed fire and mechanical vegetation removal. Findings demonstrate a relative stability of attitudes toward fuels management approaches over time and suggest that this acceptance is strongly influenced by confidence in resource managers and beliefs that the treatments would result in positive outcomes.     

Plant Community Composition and Biomass in Gulf Coast Chenier Plain Marshes: Responses to Winter Burning and Structural Marsh Management

Many marshes in the Gulf Coast Chenier Plain, USA, are managed through a combination of fall or winter burning and structural marsh management (i.e., levees and water control structures; hereafter SMM). The goals of winter burning and SMM include improvement of waterfowl and furbearer habitat, maintenance of historic isohaline lines, and creation and maintenance of emergent wetlands. Although management practices are intended to influence the plant community, effects of these practices on primary productivity have not been investigated. Marsh processes, such as vertical accretion and nutrient cycles, which depend on primary productivity may be affected directly or indirectly by winter burning or SMM. We compared Chenier Plain plant community characteristics (species composition and above- and belowground biomass) in experimentally burned and unburned control plots within impounded and unimpounded marshes at 7 months (1996), 19 months (1997), and 31 months (1998) after burning. Burning and SMM did not affect number of plant species or species composition in our experiment. For all three years combined, burned plots had higher live above-ground biomass than did unburned plots. Total above-ground and dead above-ground biomasses were reduced in burned plots for two and three years, respectively, compared to those in unburned control plots. During all three years, belowground biomass was lower in impounded than in unimpounded marshes but did not differ between burn treatments. Our results clearly indicate that current marsh management practices influence marsh primary productivity and may impact other marsh processes, such as vertical accretion, that are dependent on organic matter accumulation and decay.     

Convergent and Contingent Community Responses to Grass Source and Dominance During Prairie Restoration Across a Longitudinal Gradient

Restoring prairie on formerly cultivated land begins by selecting propagule seed sources and the diversity of species to reintroduce. This study examined the effects of dominant grass propagule source (cultivar vs. non-cultivar) and sown propagule diversity (grass:forb sowing ratio) on plant community structure. Two field experiments were established in Kansas and Illinois consisting of identical split plot designs. Dominant grass source was assigned as the whole-plot factor, and sown dominance of grasses (five levels of seeded grass dominance) as the subplot factor. Species density, cover, and diversity were quantified for 5 years. The effect of dominant grass source on the cover of focal grasses, sown species, and volunteer species was contingent upon location, with variation between dominant grass sources observed exclusively in Kansas. Species density and diversity showed regionally convergent patterns in response to dominant grass source. Contrary to our hypotheses, total species density and diversity were not lower in the presence of grass cultivars, the grass source we had predicted would be more competitive. Sown grass dominance effects on the cover of the focal grass species were contingent upon location resulting from establishment corresponding better to the assigned treatments in Illinois. All other cover groups showed regionally convergent patterns, with lower cover of volunteers and higher cover of sown forbs, diversity, and species density in the lowest sown grass dominance treatment in both sites. Thus, decisions regarding the diversity of propagules to reintroduce had more consequence for plant community structure than cultivar or non-cultivar source of dominant grasses.     

Community Responses to Government Defunding of Watershed Projects: A Comparative Study in India and the USA

When central governments decentralize natural resource management (NRM), they often retain an interest in the local efforts and provide funding for them. Such outside investments can serve an important role in moving community-based efforts forward. At the same time, they can represent risks to the community if government resources are not stable over time. Our focus in this article is on the effects of withdrawal of government resources from community-based NRM. A critical question is how to build institutional capacity to carry on when the government funding runs out. This study compares institutional survival and coping strategies used by community-based project organizations in two different contexts, India and the United States. Despite higher links to livelihoods, community participation, and private benefits, efforts in the Indian cases exhibited lower survival rates than did those in the U.S. cases. Successful coping strategies in the U.S. context often involved tapping into existing institutions and resources. In the Indian context, successful coping strategies often involved building broad community support for the projects and creatively finding additional funding sources. On the other hand, the lack of local community interest, due to the top-down development approach and sometimes narrow benefit distribution, often challenged organizational survival and project maintenance.     

Sustainable Management for the Eastern Mediterranean Coast of Turkey

The objective of this article is to propose a program for the integrated coastal zone management that is required to stimulate and guide sustainable development of the Mediterranean coastal zone of Turkey. Improved data collection, quality control, analysis, and data management will provide a firm basis for future scientific understanding of the East Mediterranean coast of Turkey and will support long-term management. Various innovative procedures were proposed for a promising ecosystem-based approach to manage coastal wetlands in the Mediterranean: remote data acquisition with new technologies; environmental quality monitoring program that will provide a baseline for monitoring; linking a Geographic Information System (GIS) with natural resource management decision routines in the context of operational wetlands, fisheries, tourism management system; environmental sensitivity analysis to ensure that permitted developments are environmentally sustainable; and use of natural species to restore the wetlands and coastal dunes and sustain the system processes. The proposed management scheme will benefit the scientific community in the Mediterranean and the management/planning community in Eastern Turkey.     

Evaluation of the Fire Simulation Processes of the National Fire Management System's Initial Attack Analysis Processor

The fire simulation processes of the National Fire Management System's (NFMAS) Initial Attack Analysis (IAA) processor were evaluated by conducting two types of sensitivity analysis: one based on a hypothetical set of data to assess IAA's outputs under a wide range of fire input values, and the other using an actual Stanislaus National Forest database to test IAA's validity with a real set of data. The results revealed that IAA's outputs (projected annual number of fires and area burned) were most sensitive, in descending order, to the input values of the fire spread rate, the productivity rates of the suppression forces, and the initial attack time, for all fuel models tested. In contrast, IAA's outputs were extremely insensitive to variations in the fire size at discovery. Changes are necessary in the ways IAA incorporates the fire size at discovery to facilitate the comparison among various fire detection options. The program's “escaped fire situation” analysis was found inadequate, because the projected annual frequencies and final sizes of the simulated escaped fire events produced unacceptable results with the Stanislaus National Forest database. Assigning final sizes to simulated escaped fires according to the fire intensity level in which they are historically expected to occur provides a consistent way of calculation of the projected annual area burned and the consequent cost plus net value change (C + NVC).     

Recent Changes in the Riparian Forest of a Large Regulated Mediterranean River: Implications for Management

The structure of the floodplain forests of the Middle Ebro River (NE Spain) was examined at patch and landscape scales along a three-step chronosequence defined according to the extent of flow regulation-induced hydrogeomorphic changes, with the ultimate purpose of producing baseline information to guide through management and restoration plans. At patch scale, a total of 6,891 stems within 39 plots were registered for species, diameter and health status. The stem density, size class distribution, canopy dieback and mortality were further compared by means of non-parametric tests. At landscape scale, the temporal evolution of the area occupied by forest stands of different ages in the floodplain along the chronosequence was evaluated using four sets of aerial photographs dated in 1927, 1957, 1981 and 2003. The within-patch structure of pioneer forests (<25–30 years old) was characterized by dense and healthy populations of pioneer species (Populus nigra, Salix alba and Tamarix spp.), but the area occupied by these forest types has progressively decreased (up to 37%) since the intensification of river regulation (ca. 1957). In contrast, non-pioneer forests (>25–30 years old) were characterized by declining and sparse P. nigra–S. alba–Tamarix spp. stands, where late-seral species such as Ulmus minor and Fraxinus angustifolia were frequent, but only as small-size stems. At landscape scale, these type of senescent forests have doubled their surface after river regulation was intensified. Populus alba only appeared in the oldest plots recorded (colonized before 1957), suggesting sexual regeneration failure during the last five decades, but usually as healthy and dense stands. Based on these findings, measures principally aimed at recovering some hydrogeomorphic dynamism are recommended to guarantee the self-sustainability of the floodplain forest ecosystem.     

Spatial Patterns of Land Use Changes Across a Mediterranean Metropolitan Landscape: Implications for Biodiversity Management

Land use and land cover change (LUCC) is an acknowledged cause of the current biodiversity crisis, but the link between LUCC and biodiversity conservation remains largely unknown at the regional scale, especially due to the traditional lack of consistent biodiversity data. We provide a methodological approach for assessing this link through defining a set of major pressures on biodiversity from LUCC and evaluating their extent, distribution, and association with a set of physical factors. The study was performed in the Metropolitan Region of Barcelona (MRB, NE of Spain) between 1956 and 2000. We generated a LUCC map for the time period, which was reclassified into a set of pressures on biodiversity (forestation, deforestation, crop abandonment, and urbanization). We then explored the association of these pressures with a set of physical factors using redundancy analysis (RDA). Pressures encompassed 38.8 % of the MRB area. Urbanization and forestation were the dominating pressures, followed by crop abandonment and deforestation. RDA showed a significant distribution gradient of these pressures in relation to the studied physical factors: while forestation and deforestation are concentrated in remote mountain areas, urbanization mainly occurs in lowlands and especially on the coast, and close to previous urban centers and roads. Unchanged areas are concentrated in rainy and relatively remote mountain areas. Results also showed a dramatic loss of open habitats and of the traditional land use gradient, both featuring Mediterranean landscapes and extremely important for their biodiversity conservation. Implications of these results for biodiversity management are finally discussed.     

火对野生动物的生态作用

本文主要阐述了自然生态系统中，火对野生动物的直接影响及其通过改变动物的栖息环境、食物组成等因素给动物带来或可能带来的间接影响。强调火烧给动物生物多样性带来的威胁。最后探讨了人类控制火因子为人类服务的问题。     

Nutrient and Phytoplankton Analysis of a Mediterranean Coastal Area

Identifying and quantifying the key anthropogenic nutrient input sources are essential to adopting management measures that can target input for maximum effect in controlling the phytoplankton biomass. In this study, three systems characterized by distinctive main nutrient sources were sampled along a Mediterranean coast transect. These sources were groundwater discharge in the Ahuir area, the Serpis river discharge in the Venecia area, and a submarine wastewater outfall 1,900 m from the coast. The study area includes factors considered important in determining a coastal area as a sensitive area: it has significant nutrient sources, tourism is a major source of income in the region, and it includes an area of high water residence time (Venecia area) which is affected by the harbor facilities and by wastewater discharges. We found that in the Ahuir and the submarine wastewater outfall areas, the effects of freshwater inputs were reduced because of a greater water exchange with the oligotrophic Mediterranean waters. On the other hand, in the Venecia area, the highest levels of nutrient concentration and phytoplankton biomass were attributed to the greatest water residence time. In this enclosed area, harmful dinoflagellates were detected (Alexandrium sp. and Dinophysis caudata). If the planned enlargement of the Gandia Harbor proceeds, it may increase the vulnerability of this system and provide the proper conditions of confinement for the dinoflagellate blooms’ development. Management measures should first target phosphorus inputs as this is the most potential-limiting nutrient in the Venecia area and comes from a point source that is easier to control. Finally, we recommend that harbor environmental management plans include regular monitoring of water quality in adjacent waters to identify adverse phytoplankton community changes.     

Ecological Responses to Trout Habitat Rehabilitation in a Northern Michigan Stream

Monitoring of stream restoration projects is often limited and success often focuses on a single taxon (e.g., salmonids), even though other aspects of stream structure and function may also respond to restoration activities. The Ottawa National Forest (ONF), Michigan, conducted a site-specific trout habitat improvement to enhance the trout fishery in Cook’s Run, a 3^rd-order stream that the ONF determined was negatively affected by past logging. Our objectives were to determine if the habitat improvement increased trout abundances and enhanced other ecological variables (overall habitat quality, organic matter retention, seston concentration, periphyton abundance, sediment organic matter content, and macroinvertebrate abundance and diversity) following rehabilitation. The addition of skybooms (underbank cover structures) and k-dams (pool-creating structures) increased the relative abundance of harvestable trout (>25 cm in total length) as intended but not overall trout abundances. Both rehabilitation techniques also increased maximum channel depth and organic matter retention, but only k-dams increased overall habitat quality. Neither approach significantly affected other ecological variables. The modest ecological response to this habitat improvement likely occurred because the system was not severely degraded beforehand, and thus small, local changes in habitat did not measurably affect most physical and ecological variables measured. However, increases in habitat volume and in organic matter retention may enhance stream biota in the long term.     

Use of ecosystem information to improve soil organic carbon mapping of a Mediterranean island

Detailed maps of soil C are needed to guide sustainable soil uses and management decisions. The quality of soil C maps of Italian Mediterranean areas may be improved and the sampling density reduced using secondary data related to the nature of the ecosystem. The current study was conducted to determine: (i) the improvements obtainable in mapping soil C over a Mediterranean island by using ecosystem features and (ii) the effect of different sampling densities on the map accuracy. This work relied on field sampling (n=164) of soil properties measured over the island of Pianosa (Central Italy). Statistical analysis assessing the relationship between soil properties and ecosystem features revealed that the conceptual model of ecosystems defined on the basis of environmental features such as vegetation cover, land use, and soil type was mainly related to the variation of soil organic carbon (OC) content and to the type of Mediterranean environment. The distribution of ecosystems was used to improve the accuracy of soil OC maps obtainable by a simple interpolation approach (ordinary kriging). Substantial improvement was obtained by: (i) stratification into ecosystem types and (ii) applying locally calibrated regressions to satellite imagery that introduced both inter-ecosystem and intra-ecosystem information linked to vegetation features. This study showed that interpolation methods using information on ecosystem distribution can produce accurate maps of soil OC in Mediterranean environments, mostly because of the linkage between soil OC and vegetation types, which are spatially fragmented and heterogeneous.     

Using Satellite Fire Detection to Calibrate Components of the Fire Weather Index System in Malaysia and Indonesia

Vegetation fires have become an increasing problem in tropical environments as a consequence of socioeconomic pressures and subsequent land-use change. In response, fire management systems are being developed. This study set out to determine the relationships between two aspects of the fire problems in western Indonesia and Malaysia, and two components of the Canadian Forest Fire Weather Index System. The study resulted in a new method for calibrating components of fire danger rating systems based on satellite fire detection (hotspot) data. Once the climate was accounted for, a problematic number of fires were related to high levels of the Fine Fuel Moisture Code. The relationship between climate, Fine Fuel Moisture Code, and hotspot occurrence was used to calibrate Fire Occurrence Potential classes where low accounted for 3% of the fires from 1994 to 2000, moderate accounted for 25%, high 26%, and extreme 38%. Further problems arise when there are large clusters of fires burning that may consume valuable land or produce local smoke pollution. Once the climate was taken into account, the hotspot load (number and size of clusters of hotspots) was related to the Fire Weather Index. The relationship between climate, Fire Weather Index, and hotspot load was used to calibrate Fire Load Potential classes. Low Fire Load Potential conditions (75% of an average year) corresponded with 24% of the hotspot clusters, which had an average size of 30% of the largest cluster. In contrast, extreme Fire Load Potential conditions (1% of an average year) corresponded with 30% of the hotspot clusters, which had an average size of 58% of the maximum. Both Fire Occurrence Potential and Fire Load Potential calibrations were successfully validated with data from 2001. This study showed that when ground measurements are not available, fire statistics derived from satellite fire detection archives can be reliably used for calibration. More importantly, as a result of this work, Malaysia and Indonesia have two new sources of information to initiate fire prevention and suppression activities.     

Herbicide transport to surface waters at field and watershed scales in a Mediterranean vineyard area

The contamination of soil and runoff water by two herbicides, diuron [N'-(3,4-dichlorphenyl)-N,N-dimethylurea] and simazine (6-chloro-N,N'-diethyl-1,3,5-triazine-2,4-diamine), were monitored on two fields, one no-till and one tilled. Experiments were carried out in a 91.4-ha watershed in southern France during the 1997 growing season in order to understand the patterns of pesticide transport from field to watershed. The persistence of the herbicides in soil was prolonged due to the climatic conditions. At the field scale, annual herbicide loads were due to overland flow and amounted to 65.6 and 6.3 g ha(-1) of diuron for the no-till and tilled field, respectively, and to 29.6 and 1.83 g ha(-1) of simazine. Maximum herbicide concentrations exceeded 580 microg L(-1) during the first storm event after application and decreased thereafter but remained for 8 mo above 0.1 microg L(-1). At the watershed outlet, estimated annual loads amounted to 4.12 g ha(-1) of diuron and 0.56 g ha(-1) of simazine. Among them, 96% of the losses in diuron and 83% of those in simazine were caused by the fast transmission through the network of ditches of the overland flow exiting the fields. For diuron, which was sprayed over most of the vineyards, its in-stream concentrations during storm flow were close to those at the outlet of the fields. The herbicide loads in baseflow were smaller than 0.2 g ha(-1). The patterns of the loads at the field and watershed scales suggested that a major part of the herbicides leaving the fields reinfiltrated to the ground water by seepage through the ditches, and was there degraded or adsorbed.     

社区共管：保护自然保护区与发展社区经济的“双赢”模式

随着生态环境的恶化和生物多样性的急剧丧失,自然保护区的建立应运而生。但遗憾的是,自然保护区的保护工作面临着来自周边社区不断增加的压力与矛盾。在这种情况下,人们便提出“社区共管”这一管理模式,     

Community and individual reaction to environmental hazards: Developing a measurement technology

This study was an attempt to develop an efficient method of monitoring and assessing how members of a community react to a toxic hazard in their community. The intent was to develop a short instrument which could be applied in multiple settings, or in the same setting several times. The methodology was a short questionnaire that addressed six issues: sources of information about the hazard, beliefs about justice and responsibility, beliefs about why the hazard is a problem, extent of active concern, involvement in community affairs, and satisfaction with life. A mailed questionnaire was developed and tested in a community near an EPA Superfund site in the United States. Results of the effort are discussed relative to the particular community studied, and relative to furthering the assessment technology begun in this research.     

Politics of Co-Optation: Community Forest Management Versus Joint Forest Management in Orissa,India

The article considers the impact of introducing government co-management policy in the form of Joint Forest Management (JFM) in an area with a five-decade-old self-organized community forest management system in Orissa, India. We ask a question that appears not to have been previously examined: What happens when JFM replaces an already existing community forest management arrangement? Our comparison of the JFM arrangement with the self-organized community forest management regime (pre- and post-2002 in a selected village) provides three conclusions: (1) The level of villager participation in forest management has declined, along with the erosion of the bundle of common rights held by them; (2) multiple institutional linkages between the village and outside agencies, and reciprocal relations with neighboring villages have been abandoned in favor of a close relationship with the Forestry Department; and (3) the administration of the forestry resource has become politicized. We conclude that the “one-size-fits-all” approach of the JFM, with its pre-packaged objectives and its narrow scope of forest management, is likely to limit experimentation, learning, and institutional innovation that characterizes community forest management.