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51.
在现代景观的体验过程中,色彩是由视觉而感知的,它既依附于具象的实体,也依赖于光这一抽象的实体而存在。该研究通过分析色彩的视觉属性、心理知觉,对现代景观设计中的色彩进行解析,从色彩在场所文化中的应用、色彩技法在景观设计中的体现几方面来阐述色彩在景观设计中的应用类型和应用方法。 相似文献
52.
Chris J. Johnson Mark S. Boyce Robert Mulders Anne Gunn Rob J. Gau H. Dean Cluff Ray L. Case 《Landscape Ecology》2005,19(8):869-882
Multiscale analyses are widely employed for wildlife-habitat studies. In most cases, however, each scale is considered discrete and little emphasis is placed on incorporating or measuring the responses of wildlife to resources across multiple scales. We modeled the responses of three Arctic wildlife species to vegetative resources distributed at two spatial scales: patches and collections of patches aggregated across a regional area. We defined a patch as a single or homogeneous collection of pixels representing 1 of 10 unique vegetation types. We employed a spatial pattern technique, three-term local quadrat variance, to quantify the distribution of patches at a larger regional scale. We used the distance at which the variance for each of 10 vegetation types peaked to define a moving window for calculating the density of patches. When measures of vegetation patch and density were applied to resource selection functions, the most parsimonious models for wolves and grizzly bears included covariates recorded at both scales. Seasonal resource selection by caribou was best described using a model consisting of only regional scale covariates. Our results suggest that for some species and environments simple patch-scale models may not capture the full range of spatial variation in resources to which wildlife may respond. For mobile animals that range across heterogeneous areas we recommend selection models that integrate resources occurring at a number of spatial scales. Patch density is a simple technique for representing such higher-order spatial patterns. 相似文献
53.
Recent research shows that land use history is an important determinant of current ecosystem function. In the United States,
characterization of land use change following European settlement requires reconstruction of the original property mosaic.
However, this task is difficult in unsystematically surveyed areas east of the Appalachian Mountains. The Gwynns Falls watershed
(Baltimore, MD) was originally surveyed in the 1600-1700s under a system of warrants and patents (commonly known as ‘metes
and bounds’). A method for the reconstruction and mapping of warrant and patent properties is presented and used to map the
original property mosaic in the Gwynns Falls watershed. Using the mapped mosaic, the persistence of properties and property
lines in the current Gwynns Falls landscape is considered. The results of this research indicate that as in agricultural areas,
the original property lines in the Gwynns Falls watershed are persistent. At the same time, the results suggest that the property
mosaic in heavily urbanized/suburbanized areas is generally ‘reset.’ Further, trends in surveying technique, parcel size,
and settlement patterns cause property line density and property shape complexity to increase in the less urbanized upper
watershed. The persistence of original patterns may be damping expression of heterogeneity gradients in this urban landscape.
This spatial pattern of complexity in the original mosaic is directly opposite of hypothesized patterns of landscape heterogeneity
arising from urbanization. The technique reported here and the resulting observations are important for landscape pattern
studies in areas settled under unsystematic survey systems, especially the heavily urbanized areas of the eastern United States.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
54.
Introduction 总被引:1,自引:0,他引:1
The realization of strategies for sustainable land use assumes specificresearch concepts from the local to the global scale (micro-, meso- andmacroscale). Therefore, landscape ecological science has to provideinvestigation methods for all these different scales. By combiningtop-down and bottom-up approaches in addition tocoupled GIS-model applications and traditional methods, the investigation oflandscape ecological structures and processes seems to be possible. Thepresented studies show this approach on examples of two study areas in EasternGermany: A watershed of 400 km2 and an administrativedistrict of about 4000 km2. The scale-specificapplicability of several models and methods were tested for theseinvestigations, and the validation of the calculated results are presented. Animportant outcome of the project should be the prevention of conflicts betweenagriculture, water management and soil, and water and nature conservation;based onrecommendations for land use variants with decreased pollutant loading withinagricultural areas. The scale specific investigations can be considered as abase for establishing sustainable land use.This revised version was published online in May 2005 with corrections to the Cover Date. 相似文献
55.
蕨类植物在园林绿化中的应用 总被引:2,自引:0,他引:2
蕨类植物种类丰富、适应性强、管理简便,非常适合园林应用。在简要分析我国蕨类植物种质资源的基础上,探讨蕨类植物在园林植物造景如庭院、地被、水景、岩石园等的应用,提出应在园林建设中重视蕨类植物,尤其是中国原产的蕨类植物和从国外引进的一些新优园艺蕨类品种,以丰富植物多样性和园林景观。 相似文献
56.
In mountainous Mediterranean regions, land abandonment processes in past decades are hypothesized to trigger secondary vegetal
succession and homogenization, which in recent years has increased the size of burned areas. We conducted an analysis of temporal
changes in landscape vegetal spatial pattern over a 15-year period (1984–1998) in a rural area of 672.3 km2 in Eastern Spain to investigate the relationship between local landscape heterogeneity and wildfire occurrence. Heterogeneity
was analyzed from textural metrics derived from non-classified remote sensing data at several periods, and was related to
wildfire history in the study area. Several neural network models found significant relationships between local spatial pattern
and future fire occurrence. In this study, sensitivity analysis of the texture variables suggested that fire occurrence, estimated
as probability of burning in the near future, increased where local homogeneity was higher. 相似文献
57.
This paper focuses on understanding human impact on landscape. Both ecological and human practices are analysed as interacting
processes. An agent-based model integrating biological and historical knowledge is used to analyse the pattern of Scots Pine
encroachment in a French Mediterranean upland. In the STIPA model, pine trees are autonomous agents and a cellular automaton
simulates land-use. We test the effects of shifting cultivation on tree establishment at the landscape scale. This allows
us to understand how agropastoral practices patterned this area from the 17th to 19th century: simulations show the importance
of shifting cultivation in limiting woodland progression. Fallow duration linked to environmental heterogeneity is a significant
factor for explaining pine dynamics and landscape patterning at the scale of the study region. We put this result in perspective
with current rangeland management policies that often consider grazing as the most relevant tool for open landscape maintenance.
Our results also show the importance of taking into account time-scale effects when linking landscape patterns to agricultural
systems. 相似文献
58.
Tobias Plieninger 《Landscape Ecology》2006,21(1):91-105
Mediterranean agroforestry landscapes, dehesas, experience significant structural changes that affect their ability to support
habitats for a rich biodiversity. The goal of this study is to provide quantitative information on loss, fragmentation, and
alteration of holm oak (Quercus ilex) stands over a 42-year period, based on two sites in the lowlands of Cáceres province, Spain. Aerial photography and orthoimages
from 1956, 1984, and 1998 were processed in a geographic information system (GIS). Important changes in demography and land-use
were rural depopulation, abandonment of traditional agricultural activities, and a sharp increase in livestock stocking levels.
These were related to intensification and extensification of land-uses determined by national and EU agricultural policies.
Results of the land cover analysis indicated that dehesas suffered an annual 0.27% and 0.04% decrease in cover in the two
sites. From 1984 loss rate had markedly accelerated (0.83% and 0.30%). Most dehesas were lost by shrub encroachment or conversion
to open grassland. Fragmentation through roads increased by 28% and 45%, while rural buildings decreased by 17% and 50% from
1956 to 1998. Mean tree density decreased from 1956 to 1984, but a recovery was found since 1984. Significant factors determining
stand densities in most time points were altitude (related with different land-uses and geological substrates), ownership,
and proximity to villages. This suggests that stand structure is controlled both by human interventions and ecological settings.
The findings support the view that opposite trends of land abandonment and intensification of land-uses arise in most northern
Mediterranean countries as an effect of the EU Common Agricultural Policy. 相似文献
59.
Repeated sequences of digitised and geo-referenced historical aerial photography provide a powerful means of understanding
landscape change. We use this method to demonstrate a landscape wide expansion of closed forest (42% increase in total coverage)
in the Australian monsoon tropics over the past five decades. Retrospective habitat suitability models (HSI) of closed forest
derived using four landscape measures (drainage distance, slope angle, aspect and elevation) for imagery taken in 1947 correctly
forecast the subsequent spatial distribution of the expansion, with topographic fire protection primarily determining the
closed-forest distribution. The dynamics of the closed forest-savanna boundary were predicted accurately by generalised linear
models, with closed-forest expansion in fire-protected sites along forest edges and regression in the more fire-prone areas.
Two factors may plausibly explain the expansion of closed forests. First, eco-ethnographic records stress the skilful use
of fire by Aboriginal people in protecting isolated and locally resource-rich closed-forest patches. Second, the recent global
increase in atmospheric CO2 may be changing the competitive balance between savanna and forest by enabling C3 trees to grow fast enough to escape the fire trap presented by flammable C4 grasses. 相似文献
60.
Recent quantitative site-based monitoring and qualitative aerial and ground traverses provide contrasting assessments of the
health of much of the arid shrublands of Western Australia extensively grazed by livestock (‘rangelands’). Although these
results seem incompatible, we explain the apparent contradictions based on landscape succession processes operating at multiple
levels of ecological organisation. Specifically, we suggest that the intact areas in which site-based monitoring is conducted
are contracting as catchment canalisation and desiccation increase. However, the impacts of these processes have not yet become
manifest at the site scale. The site-based system addresses important regional questions. These relate to the large, relatively
intact areas away from most active surface flows, which should be a focus for resource conservation, given practical limits
to repairing widespread degradation with low management inputs. We provide a complementary set of questions to provide a more
comprehensive audit of rangeland dynamics in the context of underlying hierarchical landscape patterns and processes that
might threaten intact areas. We recognise the need to match questions and levels of ecological organisation and the implications
these have for sampling. We also recognise the difficulty in producing concise statements of change for clients when reporting
on complex ecological issues and processes. Without a clearly articulated, and well understood, hierarchical model of pattern
and process within which apparently contradictory findings can be reported meaningfully, policy makers may be confused by
the results, with the consequent risk of policy inaction. 相似文献