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131.
The ecology and culture of landscape sustainability: emerging knowledge and innovation in landscape research and practice 总被引:4,自引:1,他引:3
Laura R. Musacchio 《Landscape Ecology》2009,24(8):989-992
Landscape researchers and practitioners, using the lens of sustainability science, are breaking new ground about how people’s
behaviors and actions influence the structure, function, and change of designed landscapes in an urbanizing world. The phrase—the
scientific basis of the design for landscape sustainability—is used to describe how sustainability science can contribute
to translational landscape research and practice about the systemic relationships among landscape sustainability, people’s
contact with nature, and complex place-based problems. In the first section of this article, important definitions about the
scientific basis of the design for landscape sustainability are reviewed including the six Es of landscape sustainability—environment, economic, equity, aesthetics, experience, and ethics. A conceptual framework about the six Es of landscape sustainability for designed landscapes is introduced. The interrelatedness,
opportunities, contradictions, and limitations of the conceptual framework are discussed in relation to human health/security,
ecosystem services, biodiversity, and resource management. The conceptual framework about the six Es of landscape sustainability
for designed landscapes follows the tradition in which landscape researchers and practitioners synthesize emerging trends
into conceptual frameworks for advancing basic and applied activities. 相似文献
132.
133.
The discipline of landscape ecology recognizes the importance of measuring habitat suitability variables at spatial scales
relevant to specific organisms. This paper uses a novel multi-scale hierarchical patch delineation method, PatchMorph, to
measure landscape patch characteristics at two distinct spatial scales and statistically relate them to the presence of state-listed
endangered yellow-billed cuckoos (Coccyzus americanus occidentalis) nesting in forest patches along the Sacramento River, California, USA. The landscape patch characteristics calculated were:
patch thickness, area of cottonwood forest, area of riparian scrub, area of other mixed riparian forest, and total patch area.
A third, regional spatial variable, delineating the north and south portions of study area was also analyzed for the effect
of regional processes. Using field surveys, the landscape characteristics were related to patch occupancy by yellow-billed
cuckoos. The area of cottonwood forest measured at the finest spatial scale of patches was found to be the most important
factor determining yellow-billed cuckoo presence in the forest patches, while no patch characteristics at the larger scale
of habitat patches were important. The regional spatial variable was important in two of the three analysis techniques. Model
validation using an independent data set of surveys (conducted 1987–1990) found 76–82% model accuracy for all the statistical
techniques used. Our results show that the spatial scale at which habitat characteristics are measured influences the suitability
of forest patches. This multi-scale patch and model selection approach to habitat suitability analysis can readily be generalized
for use with other organisms and systems. 相似文献
134.
Combining top-down and bottom-up dynamics in land use modeling: exploring the future of abandoned farmlands in Europe with the Dyna-CLUE model 总被引:9,自引:0,他引:9
Land use change is the result of interactions between processes operating at different scales. Simulation models at regional
to global scales are often incapable of including locally determined processes of land use change. This paper introduces a
modeling approach that integrates demand-driven changes in land area with locally determined conversion processes. The model
is illustrated with an application for European land use. Interactions between changing demands for agricultural land and
vegetation processes leading to the re-growth of (semi-) natural vegetation on abandoned farmland are explicitly addressed.
Succession of natural vegetation is simulated based on the spatial variation in biophysical and management related conditions,
while the dynamics of the agricultural area are determined by a global multi-sector model. The results allow an exploration
of the future dynamics of European land use and landscapes. The model approach is similarly suitable for other regions and
processes where large scale processes interact with local dynamics. 相似文献
135.
Russell Fairfax Rod Fensham Don Butler Kelvin Quinn Bernice Sigley James Holman 《Landscape Ecology》2009,24(10):1363-1373
There is circumstantial evidence that grasslands on the Bunya Mountains were once maintained by Aboriginal burning, and with
lack of fire under European management are being colonised by trees. To assess the efficacy of burning for maintaining grasslands,
119 fires were lit between 1996 and 2006. The total area of unburnt grasslands decreased by 27%, while grasslands burnt at
least once decreased by 1%. The density of invading trees was recorded from fixed plots on 23 grasslands burnt between one
and six times. Cassinia was virtually eliminated and the density of the Rainforest species guild slowly but continually declined. Acacia irrorata exhibited a humped response, with initial increases resulting from vegetative resprouting and gradual decline with persistent
burning. Phyllodinous Acacia and Woodland trees were the least fire sensitive guilds, having stable or increased density with repeated burning. Multi-factor
regression modelling detected no significant relationships between changes in woody plant density and the interval between
fires, fire intensity, the initial density of large trees, an index of soil moisture, or the cumulative number of fires for
any species guild. The survivorship of both Cassinia and Rainforest guilds was significantly lower with summer burning than winter burning, but a seasonal effect of burning was
not evident for other guilds. The findings suggest that regardless of fire conditions, frequent burning will reduce the number
of adult trees, maintain resprouts in an immature state, facilitate further fire and reduce the rate of grassland loss. Woodland
species are especially resilient to fire, and burning to maintain grassy ecosystems will be most successful where the main
colonisers are rainforest species and burning is conducted in summer. The findings suggest that the montane grasslands of
the Bunya Mountains were maintained by anthropogenic burning and active fire management will prolong their existence. 相似文献
136.
137.
Tradable biodiversity credit systems provide flexible means to resolve conflicts between development and conservation land-use
options for habitats occupied by threatened or endangered species. We describe an approach to incorporate the influence of
habitat fragmentation into the conservation value of tradable credits. Habitat fragmentation decreases gene flow, increases
rates of genetic drift and inbreeding, and increases probabilities of patch extinction. Importantly, tradable credit systems
will change the level of fragmentation over time for small and/or declining populations. We apply landscape equivalency analysis
(LEA), a generalizable, landscape-scale accounting system that assigns conservation value to habitat patches based on patch
contributions to abundance and genetic variance at landscape scales. By evaluating habitat trades using two models that vary
the relationship between dispersal behaviors and landscape patterns, we show that LEA provides a novel method for limiting
access to habitat at the landscape-scale, recognizing that the appropriate amount of migration needed to supplement patch
recruitment and to offset drift and inbreeding will vary as landscape pattern changes over time. We also found that decisions
based on probabilities of persistence alone would ignore changes in migration, genetic drift, and patch extinction that result
from habitat trades. The general principle of LEA is that habitat patches traded should make at least equivalent contributions
to rates of recruitment and migration estimated at a landscape scale. Traditional approaches for assessing the “take” and
“jeopardy” standards under the Endangered Species Act based on changes in abundance and probability of persistence may be
inadequate to prevent trades that increase fragmentation. 相似文献
138.
The question of what determines plant community composition is fundamental to the study of plant community ecology. We examined
the relative roles of historical land use, landscape context, and the biophysical environment as determinants of plant community
composition in regenerating citrus groves in north-central Florida. Results were interpreted in light of plant functional
traits. Herbaceous and woody plants responded differently to broad-scale variables; herbs correlated most strongly with surrounding
land cover at a scale of 8 km, while the only significant determinant of woody species distributions was local land use history.
There were significant correlations between herbaceous species and spatial context, habitat isolation, environmental variables,
and historical variables. Partial Mantel tests indicated that each variable provided a unique contribution in explaining some
of the variation in the herbaceous dataset. The correlation between woody plants and local historical variables remained significant
even with other effects corrected for. In the herbaceous community, species composition was linked to functional traits much
as expected from classical theory. While spatial influences in our study system are important for both woody and herbaceous
plants, the primary determinant of plant community composition in regenerating citrus groves is historical land use. Our results
suggest that the fine-scale mechanisms of local competition, tolerance and facilitation invoked by many classical studies
may ultimately be less important than land use history in understanding current plant community composition in regenerating
agricultural areas. 相似文献
139.
Bahiagrass (Paspalum notatum) is a warm-season grass used primarily in pastures and along highways and other low maintenance public areas in Florida.
It is also used in landscapes to some extent because of its drought tolerance. Bahiagrass can survive under a range of moisture
conditions from no irrigation to very wet conditions. Its well-watered consumptive use has not been reported previously. In
this study, bahiagrass crop coefficients (K
c) for an irrigated pasture were determined for July 2003 through December 2006 in central Florida. The eddy correlation method
was used to estimate crop evapotranspiration (ETc) rates. The standardized reference evapotranspiration (ETo) equation (ASCE-EWRI standardization of reference evapotranspiration task committee report, 2005) was applied to calculate
ETo values using on site weather data. Daily K
c values were estimated from the ratio of the measured ETc and the calculated ETo. The recommended K
c values for bahiagrass are 0.35 for January–February, 0.55 for March, 0.80 for April, 0.90 for May, 0.75 for June, 0.70 for
July–August, 0.75 for September, 0.70 for October, 0.60 for November, and 0.45 for December in central Florida. The highest
K
c value of 0.9 in May corresponded with maximum vapor pressure deficit conditions as well as cloud free conditions and the
highest incoming solar radiation as compared to the rest of the year. During the summer (June to August), frequent precipitation
events increased the cloud cover and reduced grass water use. The K
c annual trend was similar to estimated K
c values from another well-watered warm-season grass study in Florida. 相似文献
140.
Eddy covariance (EC) systems are being used to assess the accuracy of remote sensing methods in mapping surface sensible and
latent heat fluxes and evapotranspiration (ET) from local to regional scales, and in crop coefficient development. Therefore,
the objective was to evaluate the accuracy of EC systems in measuring sensible heat (H) and latent heat (LE) fluxes. For this
purpose, two EC systems were installed near large monolithic weighing lysimeters, on irrigated cotton fields in the Texas
High Plains, during the months of June and July 2008. Sensible and latent heat fluxes were underestimated with an average
error of about 30%. Most of the errors were from nocturnal measurements. Energy balance (EB) closure was 73.2–78.0% for daytime
fluxes. Thus, daylight fluxes were adjusted for lack of EB closure using the Bowen ratio/preservation of energy principle,
which improved the resulting EC heat flux agreement with lysimetric values. Further adjustments to EC-based ET included nighttime
ET (composite) incorporation, and the use of ‘heat flux source area’ (footprint) functions to compensate ET when the footprint
expanded beyond the crop field boundary. As a result, ET values remarkably matched lysimetric ET values, with a ‘mean bias
error ± root mean square error’ of −0.03 ± 0.5 mm day−1 (or −0.6 ± 10.2%). 相似文献