Revista Chilena de Historia Natural 80 (1): 27-42, 2007
RESEARCH ARTICLE
Effect of forest fragmentation on vegetation structure of Legrandia concinna
(Myrtaceae) threatened populations in south-central Chile
Habitat fragmentation is one of the main threats to ecosystems integrity. In this study we
assessed the influence of forest fragmentation on vegetation structure of populations of tree specie Legrandia concinna in
south-central Chile. Occupancy pattern of Legrandia populations in remaining fragments of native forests was described,
and relationship between landscape indices and vegetation structure variables were evaluated. Landscape indices, such as area,
proximity mean index, shape and edge distance to fragment were applied to forest cover maps generated from a Landsat ETM+
satellite scene for the year 2001. Results showed high predominance of reduced size fragments, high isolation levels and regulars
shapes of the fragments. Occupancy pattern suggests that Legrandia populations are found mainly in small and more
isolated fragments. No significant difference was found between fragment distribution with and without presence of Legrandia
related to size and isolation. However, we found that size, isolation and distance to fragment edge are significantly related to the
presence of this specie. As conservation measures for this specie, we propose to include populations with high disappearance risk in
protected areas, promote ex situ conservation and set up a monitoring program. This study sets a precedent related by linking
landscape scale information obtained from satellite imagery and vegetation structure information measured in the field with
conservation status of threatened populations. This innovative method allows monitoring changes over time to assess effectiveness of
conservation strategies for these populations.
Key words:
Legrandia
concinna, fragmentation, landscape indices, conservation
