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1.
The use of Ecosystem Services (ES) indicators can help designing, implementing and monitoring public environmental policies. Such indicators may be used as a support tool for natural resources management, like in forest areas, which are important ES providers. In this context, military areas are particularly challenging due to the nature of the activities conducted and the need to conciliate them with ecological protection, without undermining military readiness. It is argued that in addition to technical issues, considering stakeholders’ opinions is beneficial for the selection and design of ES indicators. The main aim of this research is to develop forest ES indicators supported by a participatory indicator selection process. A case study is made of an Atlantic Forest area in the Northeast of Brazil, under the jurisdiction of the Brazilian Army. To accomplish that aim, a questionnaire survey was sent to a group of stakeholders in order to evaluate an initial set of proposed 44 indicators for several forest ES. Through a weighting of stakeholders’ scores, 25 ES indicators for the Atlantic forest were obtained. The selected indicators portray the study area mainly as a provider of regulating, cultural and habitat services and less of provisioning services, which can be related with military and nature protection restrictions on the use of provisioning ES. Nevertheless, the three top-rated indicators dealt with water availability, regulation and quality (for human consumption). Together with the predominance of water-related ES that was observed (ten out of 25 indicators), this points out the relevance of forest water-related ES in the study area. On the other hand, the specificity of the military context was not clearly reflected by the indicators selected, since most of them are applicable in areas or contexts other than a military one. Alongside indicators expressing the benefits provided by nature, stakeholders’ scorings reveal recognition of the importance of biodiversity and resilience of the area. This stresses the importance of biodiversity and resilience to support ES supply, but is also linked with one of the major challenges for managing a military area with high natural value: that of conciliating military activities (that support military readiness) with nature protection. Other forest areas under military or similar particular jurisdiction, often representing a major fraction of national forests, could learn from this approach and identify areas for priority response measures. These indicators could be also a driver to increase and improve environmental management of military training activities and safeguarding natural resources in important ES providing areas like Atlantic forests.  相似文献   

2.
We examined long-term ecological change in two Hudson River tributaries, the Wappinger and Fishkill Creek watersheds in Dutchess County, New York State. Fish data spanning 65 years (1936, 1988, 1992, and 2001) and shorter term macroinvertebrate data (1988, 2001) were used to assess the influence of land use practices. Between 1988 and 2001, macroinvertebrate index Biotic Assessment Profile (BAP) improved by 113–165% in the Fishkill Creek watershed, and fish Index of Biotic Integrity (IBI) improved by 117–140%. Fish IBI and fish species richness were significantly different (p < 0.01) between the watersheds, with Wappinger Creek in better condition. Long-term fish IBI scores showed degradation in both watersheds since the 1930s. Changes in species composition suggest community homogenization on par with overall changes in the fish fauna of New York. Most notable were increases in tolerant species and declines in intolerant or moderately tolerant species. Whereas Fishkill Creek IBIs showed decline in 1988 relative to 1936, followed by improvement, Wappinger Creek declined monotonically in environmental quality. Development has intensified in both watersheds, but Fishkill Creek is improving while Wappinger Creek watershed is undergoing less mitigated degradation. We find that older, semi-quantitative data can be used to construct environmental quality indicators, and can be of great use for measuring long-term change.  相似文献   

3.
Transfer processes from a eutrophic ecosystem, the river Rhône, to an oligotrophic environment, the north-west Mediterranean Sea, were studied during the winter period, when inputs of dissolved and particulate matter are at their highest.During a cruise carried out in February 1987, salinity, temperature, turbidity, nutrients, pigments, suspended particulate matter and particulate carbon and nitrogen were measured in surface and subsurface waters near the Rhône outlet.For most of the parameters the results show that during this period a simple dilution process occurs in the river plume of the Rhône without adsorption, desorption, precipitation or biological uptake, contrary to recordings for some other rivers. All the nutrients discharged into the sea by the Rhône are available for utilization by marine phytoplankters.  相似文献   

4.
5.
Coastal dunes provide a variety of cultural and ecological ecosystem services to local communities. However, most of these ecosystems are globally threatened by anthropic factors. Chile is home to important dune ecosystems such as the emblematic Ritoque coastal dunes located in the hotspot for biodiversity conservation in central Chile where there is a delicate relationship between conservation and human development interests, among local communities and authorities. Here, we performed a choice experiment study to determined willingness to implement conservation measures in the Ritoque dunes. In particular, we assessed residents’ preferences for improvements of the current state of local ecosystem services such as scenic beauty, biodiversity and archaeological sites. Residents showed preferences for improvements in Ritoque coastal dunes’ ecosystem services, and a high willingness to pay for protecting biodiversity and archeological sites, rather than for recreational infrastructure. Our study highlights the importance of place-based research that specifically addresses residents and stakeholders’ conservation priorities, which could be used to design and implement effective conservation management strategies for coastal ecosystems and coastal cities near them.  相似文献   

6.
《Ostrich》2013,84(3):119-136
Animal population dynamics can be driven by rainfall variability through its influence on habitat suitability, availability and nutritional sufficiency of forage. To understand how rainfall influences ostriches, we related changes in ostrich recruitment in the Mara–Serengeti ecosystem to rainfall. Over a 15-year period, monthly counts of ostriches were made and the number of hatchlings, chicks, hens, cocks, and the size of the groups in which they occurred were recorded. Breeding was bimodal with a major peak in February and a minor peak in October. Ostriches formed larger groups in the wet (4.41 ± 5.17 (mean ± SD), range 1–72, n = 672 groups) than in the dry (2.49 ± 2.70, range 1–29, n = 398) season. The number of hatchlings plus chicks per hen increased across the duration of the study period and with increasing annual and early wet-season rainfall, affecting forage availability and quality. Recruitment was highest at intermediate levels of the five-year average of the late wet-season rainfall, implying that a change in long-term rainfall and habitat suitability would move recruitment away from the optimum. Outstanding adaptations to life in arid environments could make ostriches more resilient than sympatric ungulates if food shortages and water stress became more frequent because of widening climatic variability.  相似文献   

7.
The subalpine lake, Øvre Heimdalsvatn and its catchment, situated in the mountains of southern Norway, has been the subject of extensive ecosystem studies over the last 50 years covering a wide range of disciplines. The lake is located at 1,088 m a.s.l., has an area of 0.78 km2, a maximum depth of 13 m, and a catchment area of 23.6 km2. It lies more or less on the limit of the birch forest, while the catchment extends up over 1,800 m a.s.l. and into the high alpine zone. The valley is little influenced by human activity and there is no permanent habitation, although the area is used for grazing of domestic livestock during summer. Otherwise the lake and its catchment have always been important for fish and game. The catchment also received major radionuclide fallout from the Chernobyl accident in 1986. The studies include Quaternary history, the development of algorithms for remote sensing of snow conditions, long-term changes in lake ice cover and temperature, the zooplankton and benthic communities, as well as the uptake of Chernobyl radionuclides and mercury by the biota. The consequences of the introduction of the European minnow (Phoxinus phoxinus) on the benthos, zooplankton and the brown trout (Salmo trutta) have also been investigated. The lake and its catchment are widely used in university teaching and thesis work. On account of the substantial knowledge base, Øvre Heimdalsvatn is well suited to long-term monitoring.  相似文献   

8.
Plant and Soil - Plant diversity – ecosystem processes relationships are essential to our understanding of ecosystem functioning. We aimed at disentangling the nature of such relationships in...  相似文献   

9.
Srivastava DS 《Oecologia》2006,149(3):493-504
Although previous studies have shown that ecosystem functions are affected by either trophic structure or habitat structure, there has been little consideration of their combined effects. Such interactions may be particularly important in systems where habitat and trophic structure covary. I use the aquatic insects in bromeliads to examine the combined effects of trophic structure and habitat structure on a key ecosystem function: detrital processing. In Costa Rican bromeliads, trophic structure naturally covaries with both habitat complexity and habitat size, precluding any observational analysis of interactions between factors. I therefore designed mesocosms that allowed each factor to be manipulated separately. Increases in mesocosm complexity reduced predator (damselfly larva) efficiency, resulting in high detritivore abundances, indirectly increasing detrital processing rates. However, increased complexity also directly reduced the per capita foraging efficiency of the detritivores. Over short time periods, these trends effectively cancelled each other out in terms of detrital processing. Over longer time periods, more complex patterns emerged. Increases in mesocosm size also reduced both predator efficiency and detritivore efficiency, leading to no net effect on detrital processing. In many systems, ecosystem functions may be impacted by strong interactions between trophic structure and habitat structure, cautioning against examining either effect in isolation.  相似文献   

10.
During December and January, dry northeasterly surface winds (the Harmattan)distribute dust over West Africa. Rate of deposition and some chemical andphysical characteristics of Harmattan dust were measured in Taï NationalPark in the southwest corner of Côte d'Ivoire during the 1990–1991 dryseason. The dust deposition was estimated by the classical water-filled basinmethod and by using canopy drip to account for deposition on tree canopies.Contamination by local biotic debris in both, water-filled basin and canopydrip collectors, was corrected for by using Ti (which appears to be wholly ofatmospheric origin) as a reference element. Harmattan dust in Taï consistedmainly of kaolinitic silt finer than that collected in North Nigeria, closer tothe source area in the Chad basin. The estimates of seasonal deposition rateswere 33 to 47 kg ha-1 for the water-filled basin method andaround 80 kg ha-1 for the canopy drip method. The higher valuein canopy drip was in agreement with expected higher deposition of fine duston the canopies than on a water surface, and was therefore considered morereliable to estimate nutrient inputs by Harmattan dust deposition. The seasonalnutrient input by dust was thus estimated to be 0.11 kg ha-1for P, 2.5 kg ha-1 for K, 3.5 kg ha-1 for Caand 0.4 kg ha-1 for Mg.  相似文献   

11.
Insect herbivores are considered vulnerable to extinctions of their plant hosts. Previous studies of insect-damaged fossil leaves in the US Western Interior showed major plant and insect herbivore extinction at the Cretaceous–Palaeogene (K–T) boundary. Further, the regional plant–insect system remained depressed or ecologically unbalanced throughout the Palaeocene. Whereas Cretaceous floras had high plant and insect-feeding diversity, all Palaeocene assemblages to date had low richness of plants, insect feeding or both. Here, we use leaf fossils from the middle Palaeocene Menat site, France, which has the oldest well-preserved leaf assemblage from the Palaeocene of Europe, to test the generality of the observed Palaeocene US pattern. Surprisingly, Menat combines high floral diversity with high insect activity, making it the first observation of a ‘healthy’ Palaeocene plant–insect system. Furthermore, rich and abundant leaf mines across plant species indicate well-developed host specialization. The diversity and complexity of plant–insect interactions at Menat suggest that the net effects of the K–T extinction were less at this greater distance from the Chicxulub, Mexico, impact site. Along with the available data from other regions, our results show that the end-Cretaceous event did not cause a uniform, long-lasting depression of global terrestrial ecosystems. Rather, it gave rise to varying regional patterns of ecological collapse and recovery that appear to have been strongly influenced by distance from the Chicxulub structure.  相似文献   

12.
Historically, the role of parasites in ecosystem functioning has been considered trivial because a cursory examination reveals that their relative biomass is low compared with that of other trophic groups. However there is increasing evidence that parasite-mediated effects could be significant: they shape host population dynamics, alter interspecific competition, influence energy flow and appear to be important drivers of biodiversity. Indeed they influence a range of ecosystem functions and have a major effect on the structure of some food webs. Here, we consider the bottom-up and top-down processes of how parasitism influences ecosystem functioning and show that there is evidence that parasites are important for biodiversity and production; thus, we consider a healthy system to be one that is rich in parasite species.  相似文献   

13.
Experiment on jute crop was conducted during pre-kharif to kharif seasons (April to August) at Bidhan Chandra Krishi Viswavidyalaya (BCKV), West Bengal, India in a view to record the pest incidence on olitorius jute and to determine the weather parameters impacting on pest population in jute under West Bengal conditions. Seventeen different species of pests belonging to insects, mites and nematodes were found feeding on jute. Among them, jute semilooper (Anomis sabulifera Guen.), Bihar hairy caterpillar (Spilarctia obliqua Wlk.), grey weevil (Myllocerus discolor Bohemus), yellow mite (Polyphagotarsonemus latus Banks), stem weevil (Apion corchori Marshall), and root knot nematode, Meloidogyne incognita are causing economic damage to the crop and other pests were considered as minor pests. Correlation studies with weather parameters showed that incidence of semilooper was negatively correlated (r = ?0.795 to ?0.725) with the maximum temperature but had positive significant association with minimum temperature (r = 0.528–0.715), morning relative humidity (RH) (r = 0.579–0.857) and afternoon RH (r = 0.876). Bihar hairy caterpillar incidence also exhibited positive significant relationship with morning RH (r = 0.577) and afternoon RH (r = 0.545). Morning and afternoon RH and rainfall also had significant positive correlation with the incidence of M. discolor with r = 0.535, 0.570, and 0.700, respectively. None of the meteorological parameters had any significant influence on the incidence of A. corchori. Yellow mite incidence showed positive association with morning RH (r = 0.563–0.679) and afternoon RH (r = 0.526–0.618). Rainfall was found favourable for proliferation and incidence of M. discolor only but had a negative effect on the incidence of stem weevil and yellow mite. Thus climatic factors particularly temperature, relative humidity and rainfall played a pivotal role on occurrence and existence of different pests on jute crop.  相似文献   

14.
Biodiversity conservation strategies that overlook the interests of local people are prone to create conflicts. The ecosystem service approach holds potential for more comprehensively integrating the social dimension into decision-making in protected areas, but its implementation in conservation policies is still in its infancy. This research assesses the extent to which ecosystem services have been implemented in conservation strategies in protected areas. The study was conducted in two outstanding Spanish protected areas, covering a wetland (Doñana Natural and National Parks) and a Mediterranean mountain system (Sierra Nevada Natural and National Parks). Data were collected from deliberative workshops with managers and researchers, face-to-face surveys with users and a review of management plans. We found that, beyond intrinsic values of ecosystems and biodiversity, these areas provide multiple ecosystem services that deserve further attention to ensure their sustained delivery. Our research shows that environmental managers and researchers have different perceptions and priorities regarding ecosystem services management compared with ecosystem service users. Environmental managers and researchers in both protected areas perceived that human-nature relationships and ecosystem services are already widely included in management plans, if often not explicitly. We found that different ecosystem service categories receive uneven attention in management plans. These contained measures to manage provisioning and cultural services whereas measures for managing regulating services were perceived to be largely absent. We conclude by summarizing insights on how the ecosystem service approach may enhance the consideration of social interests in the management of management protected areas.  相似文献   

15.
The Paris agreement on climate change requires rapid reductions in greenhouse gas emissions. One important mitigation strategy, at least in the intermediate future, is the substitution of fossil fuels with bioenergy. However, using agriculture- and forest-derived biomass for energy has sparked controversy regarding both the climate mitigation potential and conflicts with biodiversity conservation. The urgency of the climate crisis calls for using forests for carbon sequestration and storage rather than for bioenergy, making agricultural biomass an attractive alternative for fossil energy substitution. However, this calls for comprehensive assessments of its sustainability in terms of consequences for biodiversity and ecosystem services. In this review, we provide a first holistic overview of the impacts on ecosystems of land-use changes from bioenergy crop production in temperate climates, by synthesizing results on both biodiversity and ecosystem service impacts. We found that bioenergy-related land-use changes can have both positive and negative effects on ecosystems, with original land use, bioenergy crop type and scale of bioenergy production being important moderators of impacts. Despite the risk of opportunity cost for food production, perennial crop cultivation on arable land had the lowest occurrence of negative impacts on biodiversity and ecosystem services. Growing biomass for bioenergy on surplus land has been suggested as a way to alleviate competition with food production and biodiversity conservation, but our results demonstrate that utilizing marginal or abandoned land for bioenergy crop production cannot fully resolve these trade-offs. Furthermore, there is a lack of empirical studies of the biodiversity value of marginal and abandoned land, limiting our understanding of the sustainability implications of biomass cultivation on surplus land. We argue that future research and policies for bioenergy production must explicitly consider biodiversity and ecosystem services in combination to avoid potential trade-offs between the two and to ensure sustainable bioenergy production.  相似文献   

16.

Background and aims

Our objective was to assess the effects of long-term continuous grazing on soil enzyme activities in relation to shifts in plant litter attributes and soil resources in an arid ecosystem, considering both spatial and temporal variations.

Methods

We randomly extracted soil samples with the respective litter cover at 5 modal size plant-covered patches (PCP) and the nearest inter-canopy areas (IC) at Patagonian Monte sites with low, medium and high grazing intensity in winter and summer from 2007 to 2009. We analyzed enzyme activities (dehydrogenase, ß-glucosidase, protease, alkaline and acid phosphatase), microbial biomass-C, organic-C, total soil-N, and moisture in soil and mass and quality in plant litter. We assessed faeces density and plant cover in the field.

Results and conclusions

Grazing led to reduced grass cover, decreasing plant litter mass with increasing soluble phenolics, and reduced phosphatases, ß-glucosidase and microbial biomass-C at PCP. A localized nutrient input from animal excreta seems to promote microbial biomass-C, alkaline phosphatase and dehydrogenase activities but only at IC from the site with high grazing intensity. Plant heterogeneous distribution, plant litter quantity and quality, nutrient inputs from grazers and seasonal variation in soil moisture, also affecting soil resources and microbial biomass, modulate soil enzyme responses to long-term grazing in the arid Patagonian Monte.  相似文献   

17.
The projected recession of forests in the forest–steppe ecotone under projected climate drying would restrict the carbon sink function of terrestrial ecosystems. Previous studies have shown that the forest–steppe ecotone in the southeastern Inner Mongolia Plateau originally resulted from climate drying and vegetation shifts during the mid- to late-Holocene, but the interrelated processes of changing soil carbon storage and vegetation and soil shifts remain unclear. A total of 44 forest soil profiles and 40 steppe soil profiles were excavated to determine soil carbon storage in deciduous broadleaf forests (DBF), coniferous forests (CF) and steppe (ST) in this area. Carbon density was estimated to be 106.51 t/hm2 (DBF), 73.20 t/hm2 (CF), and 28.14 t/hm2 (ST) for these ecosystems. Soil organic carbon (SOC) content was negatively correlated with sand content (R = −0.879, P < 0.01, n = 42), and positively correlated with silt (R = 0.881, P < 0.01, n = 42) and clay (R = 0.858, P < 0.01, n = 42) content. Consistent trends between fractions of coarse sand and a proxy index of relative aridity in sediment sequences from two palaeo-lakes further imply that climate drying reduced SOC through coarsening of the soil texture in the forest–steppe ecotone. Changes in carbon storage caused by climate drying can be divided into two stages: (1) carbon storage of the ecosystem was reduced to 68.7%, mostly by soil coarsening when DBF were replaced by CF at ~5,900 14C years before present (BP); and (2) carbon storage was reduced to 26.4%, mostly by vegetation shifts when CF were replaced by ST at ~2,900 14C years BP.  相似文献   

18.
生物多样性常常和生态系统多功能性(生态系统同时提供多个生态系统功能的能力)正相关。然而,生物多样性与生态系统多功能性的关系是否依赖于生态系统功能的数目有诸多争议。其中,生物多样性对生态系统多功能性的影响或许不随生态系统功能数目的变化而变化,或者随生态系统功能数目的增多而增强。我们期望通过研究不同生态系统多功能性指数的统计原理来解决这些争议。 我们使用了模型模拟和一系列来自不同空间尺度(从局域到全球)和不同生物群系(温带和高寒草地、森林和干旱地)的经验数据。我们回顾了量化生态系统多功能性的三种方法,包括平均值法、加和法和阈值法。我们发现随着生态系统功能数目的增加,生物多样性与生态系统多功能性的关系要么不变,要么增强。这些结果可由平均和加和的多功能性指数的统计原理来解释。具体来讲,当利用生态系统功能的平均值计算多功能性指数时,由于多样性对多功能性的效应等于多样性对单个生态系统功能效应的平均值,所以不会随生态系统功能数目的变化而变化。同样的道理,当利用单个生态系统的加和值计算多功能性指数时,多样性的效应会随着生态系统功能数目的增加而增强。我们提出了一个改进的多功能性指数,将平均或加和多功能性指数转化为标准化的多功能性指数, 以便于对不同研究的结果进行比较。此外,我们提出了基于变量数值范围的标准化方法来解决阈值法的数学假象问题(多样性效应随生态系统功能数目的增加而增强)。我们的研究结果表明,量化多功能性指数的方法不同,结果也不同。因此,有必要加深对不同方法数理基础的理解。而标准化的多功能性指数为比较不同研究中的生物多样性与生态系统多功能性的关系提供了有效的方法。  相似文献   

19.
In this paper, we investigate the problem of secondary extinction in food webs through the use of dominator trees, network topological structures that reduce food webs to linear pathways that are essential for energy delivery. Each species along these chains is responsible for passing energy to the taxa that follow it, and, as such, it is indispensable for their survival; because of this it is said to dominate them. The higher the number of species a node dominates, the greater the impact resulting from its removal. By computing dominator trees for 13 well-studied food webs we obtained for each of them the number of nodes dominated by a single species and the number of nodes that dominate each species. We illustrate the procedure for the Grassland Ecosystem showing the potential of this method for identifying species that play a major role in energy delivery and are likely to cause the greatest damage if removed. Finally, by means of two indices that measure error and attack sensitivity, we confirm a previous hypothesis that food webs are very robust to random loss of species but very fragile to the selective loss of the hubs.  相似文献   

20.
Experiments have been carried out in Lake Lugano, Switzerland, in order to study the biodegradation of poly(3-hydroxyalkanoates) (PHA) in an aquatic ecosystem under natural conditions. Commercially available plastic articles made from PHA, such as bottles and films, were incubated for 254 days in a water depth of 85 m. Shampoo bottles were positioned precisely on the sediment surface by the use of a small manned submarine. A set of bottles was attached to a buoy in order to incubate plastic material in diffent water depths. When incubated in the water column or on the sediment surface, a life span of five to ten years for this specific bottle type was calculated. In situ degradation rates of 10 to 20 mg/d were determined. PHA films were completely degraded when incubated in the top 20 cm of the sediment. The results clearly demonstrate that in an aquatic ecosystem (water column as well as sediment) under in situ conditions (i.e. low temperatures, seasonal variations of the oxygen concentration) plastic goods made from PHA are degraded.  相似文献   

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