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1.
Vicenç Bros 《Forest Ecology and Management》2011,261(3):611-619
In fire-prone regions, understanding the response of species to fire is a major goal in order to predict the effects on biodiversity. Furthermore, postfire management can also model this response through the manipulation of environmental characteristics of the burnt habitat. We have examined the taxonomic and functional response to fire and postfire management of a Mediterranean snail community affected by a summer fire in 2003. After the fire, the area was logged, leaving wood debris on the ground, and three alternative practices were implemented in several plots within the burnt area: subsoiling, removal of trunks having branches, total removal of trunks and branches, as well as one area not logged. Our results indicated that fire exerted a major impact on the snail community, strongly reducing diversity and species richness, particularly for forest species living in the humus and having European distribution ranges. By contrast, we found slight differences within the postfire practices, presumably because of the strong initial impact of fire and subsequent xerophilous postfire conditions. However, the area with only trunk removal showed a positive response of generalist snail species, probably due to moist microhabitats provided by the accumulation of wood debris on the ground. The effects of postfire management should be further explored due to the expected increase of fire risk associated with climate change and land-use histories. 相似文献
2.
Widespread declines of foundation species, such as many corals, kelps, and overstory trees, are of grave concern because, by definition, these species create and maintain habitat that supports other species. Nevertheless, past responses to their declines, many of which were caused by invasive species, have been late and ineffective, underscoring the need to predict changes in biodiversity and ecosystem function associated with species invasions and foundation species losses. One predictive, but under-used, approach is to compare the species and functions associated with the afflicted foundation species to its projected replacement communities. The taxa associated with the foundation species and subsequent successional stages would be expected to decline and increase, respectively. We used this approach to generate hypotheses for how arthropod diversity might change in response to extensive losses of eastern hemlock trees caused by the invasive, hemlock woolly adelgid (insect: Hemiptera, Adelgidae). Our all-strata survey of the arthropods in an eastern hemlock forest and its expected replacement climax community in the mid-Atlantic region of the United States, mixed hardwood forest, suggests that eastern hemlock losses might initiate increases in arthropod abundance, alpha diversity, and 23 arthropod taxa, might produce no change in evenness or composition of arthropod functional groups, but might trigger decreases in beta diversity and seven hemlock indicator taxa. These predictions are consistent with observed trends in arthropod responses to hemlock losses in other studies, and thus might be useful for targeting early monitoring, management, and conservation efforts. This research is exploratory, however, and tests of these predictions across larger spatial scales will be necessary to determine the generality of the findings. 相似文献
3.
Key message
In the African rim of the Western Mediterranean Basin, cork oak forests and pine plantations coexist. Under similar fire regimes, cork oak forest is more resilient in terms of habitat structure (canopy, understory, and complexity of vegetation strata) than pine plantation. By contrast, both woodland types show similar resilience in plant species composition. Resilience in habitat structure varies between the two woodland types because of the resprouting and seeding strategies of cork oak and pine species, respectively. These differences can be relevant for the conservation of biodiversity of forested ecosystems in a future scenario of increased fire frequency and scale in the Mediterranean basin.Context
Wildfires have major impacts on ecosystems globally. In fire-prone regions, plant species have developed adaptive traits (resprouting and seeding) to survive and persist due to long evolutionary coexistence with fire. In the African rim of the Western Mediterranean Basin, cork oak forest and pine plantation are the most frequently burnt woodlands. Both species have different strategies to respond fire: cork oak is a resprouter while pines are mostly seeders.Aims
We have examined the hypothesis that pine plantations are less resilient in habitat structure (canopy, understory, diversity of vegetation strata) and plant composition than cork oak woodlands.Methods
The habitat structure and plant species composition were measured in 30 burnt and 30 unburnt 700-m transects at 12 burnt sites from north-western Africa, where the two forest types can coexist. Habitat structure and plant species composition were compared between burnt and unburnt transects from cork oak and pine plantation woodlands with generalized linear mixed models and general linear models.Results
The results showed significant interaction effect of fire and forest type, since cork oak forest was more resilient to fire than was pine plantation in habitat structure. By contrast, both forest types were resilient to fire in the composition of the plant communities, i.e., plant composition prior to fire did not change afterwards.Conclusion
The higher structural resilience of cork oak forest compared to pine plantation is related to the resprouting and seeding strategies, respectively, of the dominant tree species. Differences in the responses to fire need to be considered in conservation planning for the maintenance of the Mediterranean biodiversity in a future scenario of changes in fire regime.4.
Montados are silvo-pastoral systems, typical of the western Mediterranean Basin. When well managed, these ecosystems provide relevant ecosystem services and biodiversity conservation. In the northern part of the Mediterranean Basin, cork oak areas are mainly privately owned and a source of income to landowners, chiefly through cork and livestock production. Sustainable use is essential to maintain the ecological sustainability and socio-economic viability of these ecosystems. Biodiversity conservation and non-provisioning ecosystem services may generate additional incentives promoting sustainable use and conservation of montados, but require adequate mapping and identification. The high conservation value forest (HCVF) framework allows systematic inventory of biodiversity and non-provisioning ecosystem services and is widely applied in forest ecosystems. Here we exemplify the application of HCVF to the cork oak landscape of southern Portugal using a WebGIS tool that integrates the HCVF framework, in conjunction with Pareto optimization, to identify areas important for the conservation of biodiversity and ecosystem services. We present a case study using threatened bird and reptile species, as examples of biodiversity attributes, and carbon storage and water recharge rate of aquifers, as examples of ecosystem services attributes. We identify those areas in a cork oak landscape of southern Portugal where biodiversity and ecosystem services attributes are optimized. These areas can be prioritized for implementing conservation mechanisms, such as payment for ecosystem services, to promote sustainable forest management. 相似文献
5.
《Forest Ecology and Management》2002,155(1-3):347-356
Modeling silviculture after natural disturbance to maintain biodiversity is a popular concept, yet its application remains elusive. We discuss difficulties inherent to this idea, and suggest approaches to facilitate implementation, using longleaf pine (Pinus palustris) as an example. Natural disturbance regimes are spatially and temporally variable. Variability leads to a range of structural outcomes, or results in different pathways leading to similar structures. In longleaf pine, lightning, hurricanes, surface fires, and windthrow all lead to similar structures, but at different rates. Consequently, a manager can select among various natural disturbance patterns when searching for an appropriate silvicultural model. This facilitates management by providing flexibility to meet a range of objectives. The outcomes of natural disturbances are inherently different from those of silviculture, for example, harvesting always removes boles. It is instructive to think of silvicultural disturbances along a gradient in structural outcomes, reflecting degree of disparity with natural disturbance. In longleaf pine this might involve managing for two-cohort structure, instead of multi-cohort structure characteristic of old growth stands. While two-cohort structure is a simplification over the old growth condition, it is an improvement over single-cohort management. Reducing structural disparity between managed and unmanaged forests is key to sustaining biodiversity because of linkages that exist between structural elements, forest biota, and ecosystem processes. Finally, interactions of frequency, severity, intensity, seasonality, and spatial pattern define a disturbance regime. These components may not have equal weight in affecting biodiversity. Some are easier to emulate with silviculture than are others. For instance, ecologists consider growing-season fire more reflective of the natural fire regime in longleaf pine and critical for maintenance of biodiversity. However, dormant season fire is easier to use and recent work with native plants suggests that seasonality of fire may be less critical to maintenance of species richness, as one component of biodiversity, than is generally believed. Science can advance the goal of modeling silviculture after natural disturbances by better illustrating cause and effect relationships among components of disturbance regimes and the structure and function of ecosystems. Wide application requires approaches that are adaptable to different operational situations and landowner objectives. A key point for managers to remember is that strict adherence to a silvicultural regime that closely parallels a natural disturbance regime may not always be necessary to maintain biodiversity. We outline examples of silvicultural systems for longleaf pine that demonstrates these ideas. 相似文献
6.
Climate change impacts,adaptive capacity,and vulnerability of European forest ecosystems 总被引：3，自引：0，他引：3
Marcus Lindner Michael Maroschek Sigrid Netherer Antoine Kremer Anna Barbati Jordi Garcia-Gonzalo Rupert Seidl Sylvain Delzon Piermaria Corona Marja Kolström Manfred J. Lexer Marco Marchetti 《Forest Ecology and Management》2010
This study compiles and summarizes the existing knowledge about observed and projected impacts of climate change on forests in Europe. Forests will have to adapt not only to changes in mean climate variables but also to increased variability with greater risk of extreme weather events, such as prolonged drought, storms and floods. Sensitivity, potential impacts, adaptive capacity, and vulnerability to climate change are reviewed for European forests. The most important potential impacts of climate change on forest goods and services are summarized for the Boreal, Temperate Oceanic, Temperate Continental, Mediterranean, and mountainous regions. Especially in northern and western Europe the increasing atmospheric CO2 content and warmer temperatures are expected to result in positive effects on forest growth and wood production, at least in the short–medium term. On the other hand, increasing drought and disturbance risks will cause adverse effects. These negative impacts are very likely to outweigh positive trends in southern and eastern Europe. From west to east, the drought risk increases. In the Mediterranean regions productivity is expected to decline due to strongly increased droughts and fire risks. 相似文献
7.
林火干扰与森林群落动态研究综述 总被引：3，自引：0，他引：3
林火是森林生态系统最常见的干扰类型,在森林群落演替中起着重要的作用。本文回顾了林火对森林群落演替的影响、物种对火干扰的适应、火干扰与森林更新、火干扰与物种和景观多样性、火干扰森林群落动态的研究方法,讨论了未来研究方向。 相似文献
8.
9.
This review summarizes the current state of knowledge on pine and oak forest dynamics in the mid-montane central Himalayan forest and the ecosystem services associated with these vegetation types. Forest ecosystems play a crucial role in the livelihood of the central Himalayas as well as the adjacent plains, providing a number of tangible and intangible ecosystem services, at each stage of succession. The successional sequence starts from warm temperate grasslands, followed by early successional pine forests, mid-successional pine-oak mixed forests and eventually culminating in a late successional oak community. This successional sequence is considerably influenced by disturbances like fire, grazing, and lopping, which maintain the vegetation types in their current form and can act as potential drivers of change. Fire and grazing in grasslands and pine forests inhibit the successional process by hindering the establishment of pioneer and late successional species, respectively. Potential land-cover changes with forest succession can lead to changes in ecosystem services supply. We found that the number of ecosystem services associated with these vegetation types increase from early to late successional community. Current management approaches fail to include the dynamic nature of vegetation, which is essential for maintenance of ecosystem service supply. In conclusion, the trade-offs between ES of global (biodiversity and carbon) and local importance (fuel wood and fodder) have to be examined carefully in order to have effective conservation and management plans for the region. 相似文献
10.
11.
《Forest Policy and Economics》2002,4(1):43-54
All of the Mediterranean countries face a serious forest fire problem. The main factors that affect the problem of forest fires in Greece are vegetation, climate conditions and most of all, arson (Proceedings of Forest Fires in Greece, Thessaloniki, 1990, p. 97). In Greece, after 1974, the number of forest fires and the total burned areas have risen dramatically. The design of an effective fight and prevention policy is a very important matter, as it can minimize the destruction. This paper describes an expert system that classifies the prefectures of Greece into forest fire risk zones, using a completely new methodology. The concept of fuzzy expected intervals (F.E.I.) was defined by Kandel and Byatt (Proc. IEEE, 66, 1978, 1619) and offered a very good approach towards forest fire risk classification. Fuzzy expected intervals are narrow intervals of values that best describe the forest fire problem in the country or a part of the country for a certain time period. Fuzzy logic was applied to produce a F.E.I. for each prefecture of the country. A successful classification of the prefectures of Greece (in forest fire risk zones) was performed by the expert system by comparing the produced fuzzy expected intervals to each other and by using a supervised machine learning algorithm that assigns a certain weight of forest fire risk to each prefecture (Machine Learning, John Wiley and Sons, 1995). 相似文献
12.
Forest changes over a century in Sardinia: implications for conservation in a Mediterranean hotspot 总被引：1，自引：0，他引：1
The Mediterranean basin is one of the most important biodiversity hotspots. However, only 5% of its original vegetation is still in place, and the landscape has been managed and transformed by humans for at least the last two millennia. In the last century the mechanization of agriculture and the over-use of semi-natural habitats have influenced the region even more than before, with huge consequences, especially on islands. Sardinia is the second largest island in the Mediterranean basin, and it has been considered for long as a semi-natural area with an economy based on traditional agroforestry and pastoral practices. Considering four maps covering Sardinia and ranging from 1935 to 2007, we measured the rate of forest changes demonstrating a constant trend towards forest increase, and with a complete recovery of the total forest surface compared to the late 1800s. The traditional agroforestry practices decrease in time due to socio-economic reasons, with deeper consequences for the mosaic of traditional agricultural areas and semi-natural habitats, as well as for the conservation of the unique biodiversity of Sardinia. Species typically linked to Mediterranean forests recovered and are recovering, while species linked to traditional semi-natural landscapes decreased, facing conservation problems. We suggest that the current challenges for biodiversity conservation in the island should be focused together with the agricultural policies towards the preservation and improvement of traditional open areas, even important in the history of the entire Mediterranean hotspot. 相似文献
13.
Major changes in Mediterranean forests have occurred in recent decades, mainly as a result of the abandonment of traditional
activities and population decline in rural areas. In this study, we analyzed the short-term (11-year) evolution of forests
in the region of Catalonia (NE Spain) and the role of management, by comparing seven biodiversity indicators estimated from
7,664 plots from the Second and Third Spanish National Forest Inventory. We evaluated the changes in unmanaged and managed
stands with different silvicultural treatments, and considered the effect of stand density and land ownership on these dynamics.
We found a general naturalization and maturation of forests and an increase in all of the biodiversity indicators investigated
during the study period, with the increments being greater in unmanaged than in managed plots. Some types of silvicultural
treatments, such as selection cutting or thinning, were shown to be compatible with an increase in the analyzed indicators,
and thus were more adequate for a multifunctional management that considers forest production together with the maintenance
or improvement of the diversity of forest communities. The increases in shrub species richness and in the number of large-diameter
trees after silvicultural treatments were more prominent in dense stands. Private lands presented greater short-term increases
than public forests in all biodiversity indicators, except for large-diameter trees. From these results, we concluded that
the application of silvicultural treatments can be a key tool to shape and maintain diverse and healthy forest structures
in the context of socioeconomic and environmental changes in the Mediterranean region, which may induce potentially excessive
densification and homogenization of some forest stands and landscapes. 相似文献
14.
采用人工清理和计划烧除相结合的方法建立并维护改培型蒙古栎生物防火林带,对建设前后防火林带的林分结构、可燃物载量及土壤环境等因子对比分析的结果表明：防火林带内优势树种基本都是耐火树种,建设和维护防火林带的过程中,胸径〉2cm的乔木树种未发生明显变化;林带下土壤物理性质和养分含量未产生显著影响;可燃物载量大幅减少,一般在2t／ha以下;卫生条件有了显著改善,可有效地阻隔低强度地表火和地下火的蔓延,并可以此为依托采取适当措施有效控制高强度森林大火的发生和蔓延。 相似文献
15.
It is widely accepted that for many North American forest ecosystems, changes in species composition and structure are associated with departures from natural disturbance regimes (e.g., fire exclusion). It also widely accepted that restoration of species composition and structure, similar to those which existed under natural disturbance regimes, will in turn restore and maintain: (1) ecosystem resilience to a broad range of environmental challenges; (2) important elements of ecosystem function; and (3) disturbance-adapted species assemblages and thus conservation of biodiversity. Much of the research relevant to emulating natural disturbance regimes (ENDR) in North America has focused on natural fire regimes, particularly those characterized by frequent/low-severity fires. Increasingly, attention is being focused on natural disturbance regimes other than fire and on interactions between different disturbance types. However, the greatest challenges to implementation of ENDR are socioeconomic rather than ecological. There is, for example, limited social acceptance of management based on high-severity natural disturbance regimes. And while there is much broader acceptance of ENDR based on frequent/low-severity disturbance regimes, there is nevertheless strong disagreement concerning how ENDR is to be implemented. 相似文献
16.
不炼山造林技术及应用效果 总被引：4，自引：0，他引：4
不炼山造林具有防止水土流失、保持土壤肥力、保护生物多样性、保护林区生态环境、减少CO2及烟尘大量排放、预防和减少森林火灾发生等优点,其生态和社会效益均明显高于炼山造林,利大于弊。为了进一步推广应用不炼山造林技术,从科学采伐、林地清理、整地挖穴、树种选择、良种壮苗、混交造林、控草抚育等技术环节总结了应用此项技术的实践经验,并对其推广应用的成效进行了初步评价。 相似文献
17.
Javier Madrigal Irma Fernández-Migueláñez Carmen Hernando Mercedes Guijarro Daniel J. Vega-Nieva Eduardo Tolosana 《European Journal of Forest Research》2017,136(1):13-26
The Mediterranean basin is a fire-prone area and is expected to continue being so according to projected climate and socioeconomic changes. Sustainable exploitation of forest biomass could have a positive effect on wildfire hazard mitigation. A modelling approach was used to compare how four different Scenarios for biomass collection for energy use affect fire behaviour and potential burnt area at landscape level under extreme meteorological conditions in a typical Mediterranean Massif. A case study of Pinus halepensis stands in Valencia (Eastern Spain) was conducted. The FARSITE simulator was used to evaluate the burnt area and fire behaviour parameters. Simulations predicted a significant increase in the burnt area and the values of most fire behaviour parameters in a Scenario of rural abandonment, relative to the current situation. Biomass management through thinning reduced canopy bulk density; however, no differences in the values of the main fire behaviour parameters were detected. Thinning and understory clearing, including biomass collection in large shrub fuel model areas, significantly reduces fire hazard. Forest biomass sustainable harvesting for energy is expected to reduce fire hazard if management includes intense modification of fuel models, comprising management of shrub biomass at the landscape level. Strong modification of forest fuel models requires intensive silvicultural treatments. Therefore, forest biomass collection for energy in the Mediterranean basin reduces fire hazard only if both tree and shrub strata are managed at landscape level. 相似文献
18.
火是森林生态系统演替过程中的一种自然干扰因子, 在促进森林发育、维持生物多样性特别是景观多样性方面起着积极的作用。森林中的多种干扰间有关联性, 火灾、虫害和病原体之间存在着复杂的相互作用。文中综述了火干扰与森林病虫害的相互影响。火灾会引起森林组成和景观的变化, 进而影响森林病虫的生存与发生条件。病虫害通过改变可燃物特性及其分布, 影响火烧频度和强度。这一研究领域的未来发展趋势是更注重火与病虫害之间的量化关系, 研究结果将为开展科学的林火管理提供理论依据, 实现森林经营的可持续。 相似文献
19.
Old trees are one of many habitat attributes associated with old forests. They are known to be required by many wildlife species including cavity-dependent birds. Forest managers need to select strategies for retaining and regrowing old trees to maintain suitable numbers over time at appropriate configurations in the forest landscape. This paper presents data from wet forests in south-eastern Australia to help elucidate the effects of different strategies on forest birds as one element of biodiversity that needs to be conserved in these forests. 相似文献
20.
《Forest Ecology and Management》2002,155(1-3):369-385
Forest ecosystem management, based partly on a greater understanding of natural disturbance regimes, has many variations but is generally considered the most promising approach to accommodating biodiversity concerns in managed forested regions. Using the Lake Duparquet Forest in the southeastern Canadian boreal forest as an example, we demonstrate an approach that attempts to integrate forest and stand-level scales in biodiversity maintenance. The concept of cohorts is used to integrate stand age, composition and structure into broad successional or stand development phases. Mean forest age (MFA), because it partly incorporates historic variability of the regional fire cycle, is used as a target fire cycle. At the landscape level, forest composition and cohort objectives are derived from regional natural disturbance history, ecosystem classification, stand dynamics and a negative exponential age distribution based on a 140 year fire cycle. The resulting multi-cohort structure provides a framework for maintaining the landscape in a semi-natural age structure and composition. At the stand level, the approach relies on diversifying interventions, using both even-aged and uneven-aged silviculture to reflect natural stand dynamics, control the passage (“fluxes”) between forest types of different cohorts and maintain forest-level objectives. Partial and selective harvesting is intended to create the structural and compositional characteristics of mid- to late-successional forest types and, as such, offers an alternative to increasing rotation lengths to maintain ecosystem diversity associated with over-mature and old-growth forests. The approach does not however supplant the necessity for complementary strategies for maintaining biodiversity such as the creation of reserves to protect rare, old or simply natural ecosystems. The emphasis on maintaining the cohort structure and forest type diversity contrasts significantly with current even-aged management in the Canadian boreal forest and has implications for stand-level interventions, notably in necessitating a greater diversification of silvicultural practices including more uneven-aged harvesting regimes. The approach also presents a number of operational challenges and potentially higher risks associated with multiply stand entries, partial cutting and longer intervals between final harvests. There is a need for translating the conceptual model into a more quantitative silvicultural framework. Silvicultural trials have been established to evaluate stand-level responses to treatments and operational aspects of the approach. 相似文献