Changes in the riparian zone of the lower Eygues River,France, since 1830

The riparian forests along braided rivers are dynamic, frequently rejuvenated by floods and channel changes, and thus dominated by pioneer to middle stages of succession; they are sites of high biodiversity in some regions. The Lower Eygues River (drainage area 1150 km² in southeastern France) is such a braided river system with large alluvial forests dominated by Salix alba, Populus alba, and P. nigra. It was identified as a site of ecological interest by the EU under the Natura 2000 program. Such forests elsewhere in Europe have been identified as reference ecosystems. We documented the historical evolution of this alluvial forest from detailed (1:2500 scale) early 19th C parcel maps, early 20th C topographic maps, aerial photography from 1947 to 1996, and field surveys of topography and riparian vegetation in 1997–1998. Our results show that in 1830, the channel was wide, aggraded, and agricultural pressure extended literally to the channel edge. With decline in the rural population and reduced agricultural and grazing pressure in the catchment, erosion rates declined. Reduced sediment supply led to channel narrowing and incision. This channel narrowing, coupled with reduced agricultural pressure along the banks, has allowed riparian forest to colonize former active channel areas, especially within late 19th-century 20th century flood dykes. In recent decades, aggregate mining, and clearing for recreation and agriculture have fragmented the forest. Thus, the alluvial forest of the Lower Eygues is largely an artifact of changing human land-use over the past century, a context that should frame efforts for preservation and restoration.     

A method for locating potential tree-planting sites in urban areas: A case study of Los Angeles, USA

A GIS-based method for locating potential tree-planting sites based on land cover data is introduced. Criteria were developed to identify locations that are spatially available for potential tree planting based on land cover, sufficient distance from impervious surfaces, a minimum amount of pervious surface, and no crown overlap with other trees. In an ArcGIS environment, a computer program was developed to iteratively search, test, and locate potential tree-planting sites by virtually planting large, medium and small trees on plantable areas, with large trees given priority as more benefits are expected to accrue to them. A study in Los Angeles, USA found 2.2 million potential planting sites, approximately 109.3 km² of potential tree canopy cover.     

A gradient analysis of urban landscape pattern: a case study from the Phoenix metropolitan region,Arizona, USA

Landscape Ecology - Urbanization is arguably the most dramatic form of land transformation that profoundly influences biological diversity and human life. Quantifying landscape pattern and its...     

Landscape planning for a rural ecosystem: case study of a resettlement area for residents from land submerged by the Three Gorges Reservoir,China

The goals of landscape planning are multiple for rural ecosystems of the resettlement area in the Hubei Province of China. They relate to the types, diversity and patterns of the ecosystems, and to the conservation of ecosystem functions and biodiversity. We were interested in the improvement of socio-economic conditions, and the promotion of the development of farmland ecosystems and natural forest ecosystems. The landscape planning took into account the conservation and the restoration of forestlands, and the reconstructions of farmlands, towns and villages. The areas of towns and villages were assigned by trade-off analysis balancing ecological, economic and social benefits. The spatial pattern of used lands was designed by a multi-criteria optimal spatial planning, resulting in the strengthening of some primary ecosystem functions. In the resettlement area forests will expand to a matrix, and cropland patches together with tree fences will form patch-corridor systems. Significant ecological, economic and social benefits can be derived from this landscape pattern.This revised version was published online in May 2005 with corrections to the Cover Date.     

Landscape patterns as habitat predictors: building and testing models for cavity-nesting birds in the Uinta Mountains of Utah,USA

The ability to predict species occurrences quickly is often crucial for managers and conservation biologists with limited time and funds. We used measured associations with landscape patterns to build accurate predictive habitat models that were quickly and easily applied (i.e., required no additional data collection in the field to make predictions). We used classification trees (a nonparametric alternative to discriminant function analysis, logistic regression, and other generalized linear models) to model nesting habitat of red-naped sapsuckers (Sphyrapicus nuchalis), northern flickers (Colaptes auratus),tree swallows (Tachycineta bicolor), and mountain chickadees (Parus gambeli) in the Uinta Mountains of northeastern Utah, USA. We then tested the predictive capability of the models with independent data collected in the field the following year. The models built for the northern flicker, red-naped sapsucker, and tree swallow were relatively accurate (84%, 80%, and 75% nests correctly classified,respectively)compared to the models for the mountain chickadee (50% nests correctly classified). All four models were more selective than a null model that predicted habitat based solely on a gross association with aspen forests. We conclude that associations with landscape patterns can be used to build relatively accurate, easy to use, predictive models for some species. Our results stress, however, that both selecting the proper scale at which to assess landscape associations and empirically testing the models derived from those associations are crucial for building useful predictive models. This revised version was published online in July 2006 with corrections to the Cover Date.