共查询到20条相似文献,搜索用时 15 毫秒
1.
The importance of the surrounding landscape to aquatic ecosystems has been well established. Most research linking aquatic
ecosystems to landscapes has focused on the one-way effect of land on water. However, to understand fully the complex interactions
between aquatic and terrestrial ecosystems, aquatic ecosystems must be seen not only as receptors of human modification of
the landscape, but also as potential drivers of these modifications. We hypothesized that the presence of aquatic ecosystems
influences the spatial distribution of human land use/cover of the nearby landscape (≤1 km) and that this influence has changed
through time from the 1930s to the 1990s. To test this hypothesis, we compared the distribution of residential, agricultural,
and forested land use/cover around aquatic ecosystems (lakes, wetlands, and streams) to the overall regional land use/cover
proportion in an area in southeast Michigan, USA; we also compared the distribution of land use/cover around county roads/highway
and towns (known determinants of many land use/cover patterns) to the regional proportion. We found that lakes, wetlands,
and streams were strongly associated with the distribution of land use/cover, that each ecosystem type showed different patterns,
and that the magnitude of the association was at least as strong as the association with human features. We also found that
the area closest to aquatic ecosystems (<500 m) was more strongly associated with land use/cover distribution than areas further
away. Finally, we found that the strength of the association between aquatic ecosystems and land use/cover increased from
1938 to 1995, although the overall patterns were similar through time. Our results show that a more complete understanding
is needed of the role of aquatic ecosystems on the distribution of land use/cover. 相似文献
2.
Agricultural expansion and deforestation are spatial processes of land transformation that impact on landscape pattern. In
peninsular Malaysia, the conversion of forested areas into two major cash crops—rubber and oil palm plantations—has been identified
as driving significant environmental change. To date, there has been insufficient literature studying the link between changes
in landscape patterns and land-related development policies. Therefore, this paper examines: (i) the links between development
policies and changes in land use/land cover and landscape pattern and (ii) the significance and implications of these links
for future development policies. The objective is to generate insights on the changing process of land use/land cover and
landscape pattern as a functional response to development policies and their consequences for environmental conditions. Over
the last century, the development of cash crops has changed the country from one dominated by natural landscapes to one dominated
by agricultural landscapes. But the last decade of the century saw urbanization beginning to impact significantly. This process
aligned with the establishment of various development policies, from land development for agriculture between the mid 1950s
and the 1970s to an emphasis on manufacturing from the 1980s onward. Based on a case study in Selangor, peninsular Malaysia,
a model of landscape pattern change is presented. It contains three stages according to the relative importance of rubber
(first stage: 1900–1950s), oil palm (second stage: 1960s–1970s), and urban (third stage: 1980s–1990s) development that influenced
landscape fragmentation and heterogeneity. The environmental consequences of this change have been depicted through loss of
biodiversity, geohazard incidences, and the spread of vector-borne diseases. The spatial ecological information can be useful
to development policy formulation, allowing diagnosis of the country’s “health” and sustainability. The final section outlines
the usefulness of landscape analysis in the policy-making process to prevent further fragmentation of the landscape and forest
loss in Malaysia in the face of rapid economic development.
相似文献
Adnan A. HezriEmail: |
3.
Wildfire, like many natural hazards, affects large landscapes with many landowners and the risk individual owners face depends
on both individual and collective protective actions. In this study, we develop a spatially explicit game theoretic model
to examine the strategic interaction between landowners’ hazard mitigation decisions on a landscape with public and private
ownership. We find that in areas where ownership is mixed, the private landowner performs too little fuel treatment as they
“free ride”—capture benefits without incurring the costs—on public protection, while areas with public land only are under-protected.
Our central result is that this pattern of fuel treatment comes at a cost to society because public resources focus in areas
with mixed ownership, where local residents capture the benefits, and are not available for publicly managed land areas that
create benefits for society at large. We also find that policies that encourage public expenditures in areas with mixed ownership,
such as the Healthy Forest Restoration Act of 2003 and public liability for private values, subsidize the residents who choose
to locate in the high-risk areas at the cost of lost natural resource benefits for others. 相似文献
4.
Regionalization, or the grouping of objects in space, is a useful tool for organizing, visualizing, and synthesizing the information contained in multivariate spatial data. Landscape pattern indices can be used to quantify the spatial pattern (composition and configuration) of land cover features. Observable patterns can be linked to underlying processes affecting the generation of landscape patterns (e.g., forest harvesting). The objective of this research is to develop an approach for investigating the spatial distribution of forest pattern across a study area where forest harvesting, other anthropogenic activities, and topography, are all influencing forest pattern. We generate spatial pattern regions (SPR) that describe forest pattern with a regionalization approach. Analysis is performed using a 2006 land cover dataset covering the Prince George and Quesnel Forest Districts, 5.5 million ha of primarily forested land base situated within the interior plateau of British Columbia, Canada. Multivariate cluster analysis (with the CLARA algorithm) is used to group landscape objects containing forest pattern information into SPR. Of the six generated SPR, the second cluster (SPR2) is the most prevalent covering 22% of the study area. On average, landscapes in SPR2 are comprised of 55.5% forest cover, and contain the highest number of patches, and forest/non-forest joins, indicating highly fragmented landscapes. Regionalization of landscape pattern metrics provides a useful approach for examining the spatial distribution of forest pattern. Where forest patterns are associated with positive or negative environmental conditions, SPR can be used to identify similar regions for conservation or management activities. 相似文献
5.
Protected areas (PAs) are cornerstones of biodiversity conservation, but small parks alone cannot support wide-ranging species,
such as the tiger. Hence, forest dynamics in the surrounding landscapes of PAs are also important to tiger conservation. Tiger
landscapes often support considerable human population in proximity of the PA, sometimes within the core itself, and thus
are subject to various land use activities (such as agricultural expansion and road development) driving habitat loss and
fragmentation. We synthesize information from 27 journal articles in 24 tiger landscapes to assess forest-cover dynamics in
tiger-range countries. Although 29% of the PAs considered in this study have negligible change in overall forest cover, approximately
71% are undergoing deforestation and fragmentation. Approximately 58% of the total case studies have human settlements within
the core area. Most changes—including agricultural expansion, plantation, and farming (52%), fuelwood and fodder collection
(43%), logging (38%), grazing (38%), and tourism and development (10%)—can be attributed to human impacts largely linked to
the nature of the management regime. This study highlights the need for incorporating new perspectives, ideas, and lessons
learned locally and across borders into management plans to ensure tiger conservation in landscapes dominated by human activities.
Given the increasing isolation of most parks due to agricultural, infrastructural, and commercial developments at the periphery,
it is imperative to conduct planning and evaluation at the landscape level, as well as incorporate multiple actors and institutions
in planning, instead of focusing solely on conservation within the PAs as is currently the case in most tiger parks. 相似文献
6.
Chantal Gascuel-Odoux Florence Massa Patrick Durand Philippe Merot Olivier Troccaz Jacques Baudry Claudine Thenail 《Environmental management》2009,43(5):921-935
While many scientific studies show the influence of agricultural landscape patterns on water cycle and water quality, only
a few of these have proposed scientifically based and operational methods to improve water management. Territ’eau is a framework
developed to adapt agricultural landscapes to water quality protection, using components such as farmers’ fields, seminatural
areas, and human infrastructures, which can act as sources, sinks, or buffers on water quality. This framework allows us to
delimit active areas contributing to water quality, defined by the following three characteristics: (i) the dominant hydrological
processes and their flow pathways, (ii) the characteristics of each considered pollutant, and (iii) the main landscape features.
These areas are delineated by analyzing the flow connectivity from the stream to the croplands, by assessing the buffer functions
of seminatural areas according to their flow pathways. Hence, this framework allows us to identify functional seminatural
areas in terms of water quality and assess their limits and functions; it helps in proposing different approaches for changing
agricultural landscape, acting on agricultural practices or systems, and/or conserving or rebuilding seminatural areas in
controversial landscapes. Finally, it allows us to objectivize the functions of the landscape components, for adapting these
components to new environmental constraints. 相似文献
7.
8.
Restoration efforts to increase wildlife habitat quality in agricultural landscapes have limited funding and are typically
done on a first come, first serve basis. In order to increase the efficiency of these restoration efforts, a prioritized ranking
system is needed to obtain the greatest increase in habitat quality possible for the fewest amount of hectares restored. This
project examines the use of a GIS based multi-criteria approach to prioritize lands for reforestation along the Kaskaskia
River in Illinois. Loss of forested area and corresponding increase in forest fragmentation has decreased songbird habitat
quality across the Midwestern United States. We prioritized areas for reforestation based on nine landscape metrics: available
agricultural land, forest cover gaps, edge density, proximity to river, 200 m corridor area, total forest core area, fringe
core area, distance to primary core value, and primary core area. The multi-criteria analysis revealed that high priority
areas for reforestation were most likely to be close to the riparian corridor and existing large blocks of forest. Analysis
of simulated reforestation (0, 0.5, 1.0, 5.0 10.0, 25.0, and 50.0% of highest priority parcels reforested) revealed different
responses for multiple landscape metrics used to quantify forest fragmentation following reforestation, but indicated that
the study area would get the greatest rate of return on reforestation efforts by reforesting 10.0% of the highest priority
areas. This project demonstrates how GIS and a multi-criteria analysis approach can be used to increase the efficiency of
restoration projects. This approach should be considered by land managers when attempting to identify the location and quantity
of area for restoration within a landscape. 相似文献
9.
Wyoming’s Green Mountain Common Allotment is public land providing livestock forage, wildlife habitat, and unfenced solitude,
amid other ecological services. It is also the center of ongoing debate over USDI Bureau of Land Management’s (BLM) adjudication
of land uses. Monitoring resource use is a BLM responsibility, but conventional monitoring is inadequate for the vast areas
encompassed in this and other public-land units. New monitoring methods are needed that will reduce monitoring costs. An understanding
of data-set relationships among old and new methods is also needed. This study compared two conventional methods with two
remote sensing methods using images captured from two meters and 100 meters above ground level from a camera stand (a ground,
image-based method) and a light airplane (an aerial, image-based method). Image analysis used SamplePoint or VegMeasure software.
Aerial methods allowed for increased sampling intensity at low cost relative to the time and travel required by ground methods.
Costs to acquire the aerial imagery and measure ground cover on 162 aerial samples representing 9000 ha were less than $3000.
The four highest correlations among data sets for bare ground—the ground-cover characteristic yielding the highest correlations
(r)—ranged from 0.76 to 0.85 and included ground with ground, ground with aerial, and aerial with aerial data-set associations.
We conclude that our aerial surveys are a cost-effective monitoring method, that ground with aerial data-set correlations
can be equal to, or greater than those among ground-based data sets, and that bare ground should continue to be investigated
and tested for use as a key indicator of rangeland health. 相似文献
10.
Understanding and Integrating Local Perceptions of Trees and Forests into Incentives for Sustainable Landscape Management 总被引:1,自引:0,他引:1
Pfund JL Watts JD Boissière M Boucard A Bullock RM Ekadinata A Dewi S Feintrenie L Levang P Rantala S Sheil D Sunderland T Sunderland TC Urech ZL 《Environmental management》2011,48(2):334-349
We examine five forested landscapes in Africa (Cameroon, Madagascar, and Tanzania) and Asia (Indonesia and Laos) at different stages of landscape change. In all five areas, forest cover (outside of protected areas) continues to decrease despite local people's recognition of the importance of forest products and services. After forest conversion, agroforestry systems and fallows provide multiple functions and valued products, and retain significant biodiversity. But there are indications that such land use is transitory, with gradual simplification and loss of complex agroforests and fallows as land use becomes increasingly individualistic and profit driven. In Indonesia and Tanzania, farmers favor monocultures (rubber and oil palm, and sugarcane, respectively) for their high financial returns, with these systems replacing existing complex agroforests. In the study sites in Madagascar and Laos, investments in agroforests and new crops remain rare, despite government attempts to eradicate swidden systems and their multifunctional fallows. We discuss approaches to assessing local values related to landscape cover and associated goods and services. We highlight discrepancies between individual and collective responses in characterizing land use tendencies, and discuss the effects of accessibility on land management. We conclude that a combination of social, economic, and spatially explicit assessment methods is necessary to inform land use planning. Furthermore, any efforts to modify current trends will require clear incentives, such as through carbon finance. We speculate on the nature of such incentive schemes and the possibility of rewarding the provision of ecosystem services at a landscape scale and in a socially equitable manner. 相似文献
11.
Applying Gap Analysis and a Comparison Index to Evaluate Protected Areas in Thailand 总被引:1,自引:0,他引:1
Trisurat Y 《Environmental management》2007,39(2):235-245
Protected areas in Thailand were first established 40 years ago. The total area of existing protected areas covers 18.2% of
the country’s land area and the Class 1 Watershed, another form of protection, encompasses 18.1%. The government of Thailand
intends to increase protected area systems to 25% of the country in 2006 and 30% in 2016. There are always questions arising
about how much is enough protected areas to effectively protect biodiversity. The objective of this article is to assess the
representation of ecosystems in the protected area network. This article also recommends which underrepresented ecosystems
should be added to fill the gaps in representativeness. The research applies a gap analysis and a comparison index to assess
the representation of ecosystems within the protected area network. The spatial analyses were applied to measure three aspects
of representativeness, namely forest type, altitude, and natural land system. The analyses indicate that the existing protected
area system covers 24.4% of the country’s land area, nearly meeting the 25% target proposed by the National Forest Policy;
and 83.8% of these areas are under forest cover. Most protected areas are situated in high altitudes, where biological diversity
is less than in lowlands. Mangrove forest and riparian floodplain are extremely underrepresented in the existing system. Peat
swamp forest, dry dipterocarp forest, and beach forest are relatively well represented. In addition, these five ecosystems
are threatened by human pressures and natural disasters; therefore, they should be targeted as high priorities for the selection
of new reserves. Future research should incorporate aquatic and marine ecosystems, as well as animal distributions, which
were not included in this research due to data unavailabilities. 相似文献
12.
Noncrop areas such as hedgerows in agricultural landscapes can perform several ecological and agronomic functions (e.g., habitat,
movement corridors, windbreak, etc.), but their dynamics and drivers of changes are often poorly known. We conducted a study
in three agricultural landscapes of southern Quebec, Canada, to assess and compare the spatial and temporal (1958–1997) dynamics
of three hedgerow networks in relation to geomorphic conditions (marine, glacial, and mixed deposit) and land-use changes.
Hedgerow networks were mapped and described in terms of their structure (density, degree of connectivity, and presence of
trees or shrubs) and their relationship to other components of the landscape (connection to woodland). Relationships were
assessed in time and space using nonparametric correlation, Mantel test, and principal components analysis (PCA). Results
show significant differences between hedgerow structure for the three landscapes and distinct temporal and spatial dynamics
that can be related to changes in management practices and agricultural policies. On marine deposits, increases in hedgerow
density did not always correspond to an increase in their degree of connectivity, suggesting a possible reduction in network
quality. On glacial deposits, hedgerow density declined following abandonment of agricultural land, but rather than disappearing,
these linear structures were integrated into adjacent brush or forested areas. Our analysis reveals the complex spatial and
temporal dynamics of the hedgerow networks and highlights the need to take into account spatial attributes such as connectivity
and connection to woodland to evaluate more accurately overall network quality. 相似文献
13.
Many ecologists focus on the effects of roads on landscapes, yet few consider how landscapes affect road systems. In this
study, therefore, we quantitatively evaluated how land cover, topography, and building density affected the length density,
node density, spatial pattern, and location of roads in Dongzhi Yuan, a typical loess region in China. Landscape factors and
roads were mapped using images from SPOT satellite (Système Probatoire d’Observation de la Terre), initiated by the French
space agency and a digital elevation model (DEM). Detrended canonical correspondence analysis (DCCA), a useful ordination
technique to explain species–environment relations in community ecology, was applied to evaluate the ways in which landscapes
may influence roads. The results showed that both farmland area and building density were positively correlated with road
variables, whereas gully density and the coefficient of variation (CV of DEM) showed negative correlations. The CV of DEM,
farmland area, grassland area, and building density explained variation in node density, length density, and the spatial pattern
of roads, whereas gully density and building density explained variation in variables representing road location. In addition,
node density, rather than length density, was the primary road variable affected by landscape variables. The results showed
that the DCCA was effective in explaining road–landscape relations. Understanding these relations can provide information
for landscape managers and transportation planners. 相似文献
14.
Eucalyptus albens (White Box) woodlands are among the most poorly conserved and threatened communities in Australia. Remnants are under further
threat from stock grazing, deteriorating soil conditions, weed invasion, and salinity. There is an urgent need to restore
degraded White Box and other woodland ecosystems to improve landscape function. However, there is still a poor understanding
of the ecology of degraded woodland ecosystems in fragmented agricultural landscapes, and consequently a lack of precise scientific
guidelines to manage these ecosystems in a conservation context. State and Transition Models (STMs) have received a great
deal of attention, mainly in rangeland applications, as a suitable framework for understanding the ecology of complex ecosystems
and to guide management. We have developed a STM for endangered White Box woodlands and discuss the merits of using this approach
for land managers of other endangered ecosystems. An STM approach provides a greater understanding of the range of states,
transitions, and thresholds possible in an ecosystem, and provides a summary of processes driving the system. Importantly,
our proposed STM could be used to clarify the level of “intactness” of degraded White Box woodland sites, and provide the
impetus to manage different states in complementary ways, rather than attempting to restore ecosystems to one pristine stable
state. We suggest that this approach has considerable potential to integrate researcher and land manager knowledge, focus
future experimental studies, and ultimately serve as a decision support tool in setting realistic and achievable conservation
and restoration goals. 相似文献
15.
Alberto L. Teixido Luis G. Quintanilla Francisco Carreño David Gutiérrez 《Journal of environmental management》2010,91(4):879-886
Changes in forested landscapes may have important consequences for ecosystem services and biodiversity conservation. In northern Spain, major changes in land use occurred during the second half of the 20th century, but their impacts on forests have not been quantified. We evaluated the dynamics of landscape and forest distribution patterns between 1957 and 2003 in Fragas do Eume Natural Park (northwestern Spain). We used orthoimages and a set of standard landscape metrics to determine transitions between land cover classes and to examine forest distribution patterns. Eucalypt plantations showed the greatest increase in area (197%) over time. Furthermore, transitions to eucalypt plantations were found in all major land cover classes. Forest showed a net decline of 20% in total area and represented 30% of the landscape area in 2003. Forest losses were mainly due to eucalypt plantations and the building of a water reservoir, while forest gains were due to increases in shrubland, meadows and cultivated fields which had been recolonised. Forest patch size and core area decreased, and edge length increased over time. In turn, increases were obtained in mean distance between forest patches, and in adjacency to eucalypt plantations and to a water reservoir. These results suggest an increase in forest fragmentation from 1957 to 2003, as well as a change in the nature of the habitat surrounding forest patches. This study shows that land use changes, mostly from eucalypt plantation intensification, negatively affected forested habitats, although some regeneration was ongoing through ecological succession from land abandonment. 相似文献
16.
Landscape planning and restoration in mine closure areas is not only an inevitable choice to sustain mining areas but also
an important path to maximize landscape resources and to improve ecological function in mine closure areas. The analysis of
the present mine development shows that many mines are unavoidably facing closures in China. This paper analyzes the periodic
impact of mining activities on landscapes and then proposes planning concepts and principles. According to the landscape characteristics
in mine closure areas, this paper classifies available landscape resources in mine closure areas into the landscape for restoration,
for limited restoration and for protection, and then summarizes directions for their uses. This paper establishes the framework
of spatial control planning and design of landscape elements from “macro control, medium allocation and micro optimization”
for the purpose of managing and using this kind of special landscape resources. Finally, this paper applies the theories and
methods to a case study in Wu’an from two aspects: the construction of a sustainable land-use pattern on a large scale and
the optimized allocation of typical mine landscape resources on a small scale. 相似文献
17.
Watson A Glaspell B Christensen N Lachapelle P Sahanatien V Gertsch F 《Environmental management》2007,40(6):880-888
Many public land management agencies are committed to understanding and protecting recreation visitor experiences. Parks Canada
is deeply committed to that objective for visitors to Canada’s National Parks. This 2004 study, informed by a 2003 qualitative
study of visitor experiences and influences on those experiences at Auyuittuq National Park in Nunavut, worked to bring 50
potential elements of visitor experiences down to five articulated dimensions of the experience that is currently being received
at this remote eastern arctic park. A hypothesized set of 17 influences on experiences, also reduced to just two factors with
similar response patterns, and with some items that did not flow into the two factors, were used in a regression analysis
to understand the relationship between experiences and factors of influence. A sample of 61.8% (84) of the total recreation
visitor population 16 years of age or older was surveyed during deregistration after the trip. Knowledge about the dimensions
of the experiences currently received and factors of influence on those experiences can be used to guide selection of indicators
for describing objectives and prescribing monitoring protocol. 相似文献
18.
Meding SM Morris LA Hoover CM Nutter WL Cabrera ML 《Journal of environmental quality》2001,30(4):1411-1420
Spray irrigation of forested land can provide an effective system for nutrient removal and treatment of municipal wastewater. Evolution of N2 + N2O from denitrifying activity is an important renovation pathway for N applied to forested land treatment systems. Federal and state guidance documents for design of forested land treatment systems indicate the expected range for denitrification to be up to 25% of applied N, and most forest land treatment systems are designed using values from 15 to 20% of applied N. However, few measurements of denitrification following long-term wastewater applications at forested land treatment sites exist. In this study, soil N2 + N2O-N evolution was directly measured at four different landscape positions (hilltop, midslope, toe-slope, and riparian zone) in a forested land treatment facility in the Georgia Piedmont that has been operating for more than 13 yr. Denitrification rates within effluent-irrigated areas were significantly greater than rates in adjacent nonirrigated buffer zones. Rates of N2 + N2O-N evolved from soil in irrigated forests ranged from 5 to 10 kg ha(-1) yr(-1) N on the three upland landscape positions and averaged 38 kg ha(-1) yr(-1) N within the riparian zone. The relationship between measured riparian zone denitrification rates and soil physical and chemical properties was poor. The best relationship was with soil temperature, with an r2 of 0.18. Overall, on a landscape position weighted basis, only 2.4% of the wastewater-applied N was lost through denitrification. 相似文献
19.
Fish habitat loss has been prevalent over the last century in Canada. To prevent further erosion of the resource base and
ensure sustainable development, Fisheries and Oceans Canada enacted the habitat provisions of the Fisheries Act in 1976. In 1986, this was articulated by a policy that a “harmful alteration, disruption, or destruction to fish habitat”
(HADD) cannot occur unless authorised with legally binding compensatory habitat to offset the HADD. Despite Canada’s progressive
conservation policies, the effectiveness of compensation habitat in replicating ecosystem function has never been tested on
a national scale. The effectiveness of habitat compensation projects in achieving no net loss of habitat productivity (NNL)
was evaluated at 16 sites across Canada. Periphyton biomass, invertebrate density, fish biomass, and riparian vegetation density
were used as indicators of habitat productivity. Approximately 63% of projects resulted in net losses in habitat productivity.
These projects were characterised by mean compensation ratios (area gain:area loss) of 0.7:1. Twenty-five percent of projects
achieved NNL and 12% of projects achieved a net gain in habitat productivity. These projects were characterised by mean ratios
of 1.1:1 and 4.8:1, respectively. We demonstrated that artificially increasing ratios to 2:1 was not sufficient to achieve
NNL for all projects. The ability to replicate ecosystem function is clearly limited. Improvements in both compensation science
and institutional approaches are recommended to achieve Canada’s conservation goal. 相似文献
20.
Quantifying Terrestrial Ecosystem Carbon Dynamics in the Jinsha Watershed, Upper Yangtze, China from 1975 to 2000 总被引:1,自引:0,他引:1
Shuqing Zhao Shuguang Liu Runsheng Yin Zhengpeng Li Yulin Deng Kun Tan Xiangzheng Deng David Rothstein Jiaguo Qi 《Environmental management》2010,45(3):466-475
Quantifying the spatial and temporal dynamics of carbon stocks in terrestrial ecosystems and carbon fluxes between the terrestrial
biosphere and the atmosphere is critical to our understanding of regional patterns of carbon budgets. Here we use the General
Ensemble biogeochemical Modeling System to simulate the terrestrial ecosystem carbon dynamics in the Jinsha watershed of China’s
upper Yangtze basin from 1975 to 2000, based on unique combinations of spatial and temporal dynamics of major driving forces,
such as climate, soil properties, nitrogen deposition, and land use and land cover changes. Our analysis demonstrates that
the Jinsha watershed ecosystems acted as a carbon sink during the period of 1975–2000, with an average rate of 0.36 Mg/ha/yr,
primarily resulting from regional climate variation and local land use and land cover change. Vegetation biomass accumulation
accounted for 90.6% of the sink, while soil organic carbon loss before 1992 led to a lower net gain of carbon in the watershed,
and after that soils became a small sink. Ecosystem carbon sink/source patterns showed a high degree of spatial heterogeneity.
Carbon sinks were associated with forest areas without disturbances, whereas carbon sources were primarily caused by stand-replacing
disturbances. It is critical to adequately represent the detailed fast-changing dynamics of land use activities in regional
biogeochemical models to determine the spatial and temporal evolution of regional carbon sink/source patterns. 相似文献