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Abstract: Mediterranean ecosystems are global hotspots of biodiversity threaten by human disturbances. Growing evidence indicates that regeneration of Mediterranean forests can be halted under certain circumstances and that successional stages can become notoriously persistent. The Mediterranean sclerophyllous forest in central Chile is been largely transformed into savannas dominated by the invasive legume tree Acacia caven as result of interacting management and ecological factors. We used multi-temporal satellite imagery to study the transition dynamics of these major vegetation types over the last four decades (1975–2008). Vegetation changes were related to indicators of resource availability (topography, water availability, solar radiance), potential propagule availability (distance to forest remnant patches) and disturbance regimes (grazing, fire occurrence and distance to roads and cities). During this study period, forests were mostly converted into Acacia savannas (46.1%). Acacia savanna was the most persistent natural vegetation type. The probability of sclerophyllous forest degradation into Acacia savanna increased on drier northern-exposed slopes, close to roads and further away from forest remnants. In contrast, forest regeneration from Acacia savanna was higher on moister southern-exposed slopes and closer to forest remnants. Acacia savannas are increasingly being converted into cultivated land on the moister locations or switching into a bare soil state in locations close to cities and further away from forest remnants. These results highlight the vulnerability of diverse sclerophyllous forests and its increasing conversion into persistent Acacia savannas in the Mediterranean region of central Chile and identify the ecological conditions for successful conservation and restoration of the native sclerophyllous forest vegetation that can be used for sensible land use planning. [Copyright &y& Elsevier]

Aim Few studies have explicitly examined the influence of spatial attributes of forest fragments when examining the impacts of fragmentation on woody species. The aim of this study was to assess the diverse impacts of fragmentation on forest habitats by integrating landscape-level and species-level approaches. Location The investigation was undertaken in temperate rain forests located in southern Chile. This ecosystem is characterized by high endemism and by intensive recent changes in land use. Method Measures of diversity, richness, species composition, forest structure and anthropogenic disturbances were related to spatial attributes of the landscape (size, shape, connectivity, isolation and interior forest area) of forest fragments using generalized linear models. A total of 63 sampling plots distributed in 51 forest fragments with different spatial attributes were sampled. Results Patch size was the most important attribute influencing different measures of species composition, stand structure and anthropogenic disturbances. The abundance of tree and shrub species associated with interior and edge habitats was significantly related to variation in patch size. Basal area, a measure of forest structure, significantly declined with decreasing patch size, suggesting that fragmentation is affecting successional processes in the remaining forests. Small patches also displayed a greater number of stumps, animal trails and cow pats, and lower values of canopy cover as a result of selective logging and livestock grazing in relatively accessible fragments. However, tree richness and β-diversity of tree species were not significantly related to fragmentation. Main conclusions This study demonstrates that progressive fragmentation by logging and clearance is associated with dramatic changes in the structure and composition of the temperate forests in southern Chile. If this fragmentation process continues, the ability of the remnant forests to maintain their original biodiversity and ecological processes will be significantly reduced. [ABSTRACT FROM AUTHOR]

Abstract: A comprehensive understanding of the patterns that occur as human processes transform landscapes is necessary for sustainable development. We provide new evidence on how landscapes change by analysing the spatial patterns of human processes in three forest landscapes in southern Chile at different states of alteration (40%–90% of old-growth forest loss). Three phases of landscape alteration are distinguished. In Phase I (40%–65% of old-growth forest loss), deforestation rates are < 1% yr−1, forests are increasingly degraded, and clearance for pastureland is concentrated on deeper soils. In Phase II (65%–80%), deforestation reaches its maximum rate of 1–1.5% yr−1, with clearance for pastureland being the main human process, creating a landscape dominated by disturbed forest and shrubland. In this phase, clearance for pastureland is the primary driver of change, with pastures expanding onto poorer soils in more spatially aggregated patterns. In Phase III (80%–90%), deforestation rates are again relatively low (<1% yr−1) and forest regrowth is observed on marginal lands. During this phase, clearance is the dominant process and pastureland is the main land cover. As a forest landscape is transformed, the extent and intensity of human processes vary according to the existing state of landscape alteration, resulting in distinctive landscape patterns in each phase. A relationship between spatial patterns of land cover and human-related processes has been identified along the gradient of landscape alteration. This integrative framework can potentially provide insights into the patterns and processes of dynamic landscapes in other areas subjected to intensifying human use. [Copyright &y& Elsevier]

Abstract: Chile has more than half of the temperate forests in the southern hemisphere. These have been included among the most threatened eco-regions in the world, because of the high degree of endemism and presence of monotypic genera. In this study, we develop empirical models to investigate present and future spatial patterns of woody species richness in temperate forests in south-central Chile. Our aims are both to increase understanding of species richness patterns in such forests and to develop recommendations for forest conservation strategies. Our data were obtained at multiple spatial scales, including field sampling, climate, elevation and topography data, and land-cover and spectrally derived variables from satellite sensor imagery. Climatic and land-cover variables most effectively accounted for tree species richness variability, while only weak relationships were found between explanatory variables and shrub species richness. The best models were used to obtain prediction maps of tree species richness for 2050, using data from the Hadley Centre’s HadCM3 model. Current protected areas are located far from the areas of highest tree conservation value and our models suggest this trend will continue. We therefore suggest that current conservation strategies are insufficient, a trend likely to be repeated across many other areas. We propose the current network of protected areas should be increased, prioritizing sites of both current and future importance to increase the effectiveness of the national protected areas system. In this way, target sites for conservation can also be chosen to bring other benefits, such as improved water supply to populated areas. [Copyright &y& Elsevier]

Abstract: Land cover and its configuration in the landscape are crucial components in the provision of biodiversity and ecosystem services. In Mediterranean regions, natural landscapes mostly covered by evergreen vegetation have been to a large extent transformed into cultural landscapes since long time ago. We investigated land cover changes in Central Chile using multi-temporal satellite imagery taken in 1975, 1985, 1999 and 2008. The major trends in this highly dynamic landscape were reduction of dryland forest and conversion of shrubland to intensive land uses such as farmland. The average net annual deforestation rate was −1.7%, and shrubland reduction occurred at an annual rate of −0.7%; agriculture, urban areas and timber plantations increased at annual rates of 1.1%, 2.7% and 3.2%, respectively, during the 1975–2008 period. Total forest and shrubland loss rates were partly offset by passive revegetation. However, most of the areas that were passively revegetated remained as shrubland and did not turn into forests due to a low capacity of forest recovery. This resulted in a progressive loss and degradation of dryland forest over the entire region. Overall, the documented land cover changes increase provisioning services such as crops, cattle, and timber that are characteristic of cultural landscapes in the area but may cause an irreversible loss of biodiversity and a depletion of other ecological services provided by forests and shrubland. The implications for conservation of this area and the need for territorial planning and adapted land-use strategies are discussed. [Copyright &y& Elsevier]

Abstract: The temperate forests of Chile are classified a biological “hotspot” as a result of their high species diversity and high endemism. However, they are being rapidly destroyed, with significant negative impacts on biodiversity. Three land-cover maps were derived from satellite imagery acquired over 25 years (1975, 1990 and 2000), and were used to assess the patterns of deforestation and forest fragmentation in the coastal range of south-central Chile. Between 1975 and 2000, there was a reduction in natural forest area of 67% in the study area, which is equivalent to an annual forest loss rate of 4.5% per year using a compound-interest-rate formula. Forest fragmentation was associated with a decrease in forest patch size, which was associated with a rapid increase in the density of small patches (<100ha), and a decrease in area of interior forest and in connectivity among patches. Since the 1970s, native forest loss was largely caused by an expansion of commercial plantations, which was associated with substantial changes in the spatial configuration of the native forests. By 2000, most native forest fragments were surrounded by highly connected exotic-species plantations. The assessment of forest loss and fragmentation provides a basis for future research on the impacts of forest fragmentation on the different component of biodiversity. Conservation strategies and land use planning of the study area should consider the spatial configuration pattern of native forest fragments and how this pattern changes over time and space at landscape level. [Copyright &y& Elsevier]