%0 Journal Article
%T Relationship between fragmentation, degradation and native and exotic species richness in an Andean temperate forest of Chile Relaci車n entre fragmentaci車n, degradaci車n y riqueza de especies nativas y ex車ticas en un bosque templado andino de Chile
%A ISABEL ROJAS
%A PABLO BECERRA
%A NICOL芍S G芍LVEZ
%A JERRY LAKER
%J Gayana. Botanica
%D 2011
%I Universidad de Concepci車n
%X Human impact such as forest fragmentation and degradation may have strong effects on native and exotic plant communities. In addition, these human-caused disturbances occur mostly in lowlands producing greater fragmentation and degradation there than in higher elevations. Plant invasion should be greater in more fragmented and degraded forests and hence lowlands should be more invaded than higher elevations. In turn, native species richness should be negatively related to fragmentation and degradation and hence greater in higher elevations within a forest type or elevation belt. We assessed these hypotheses in an Andean temperate forest of southern Chile, Araucan赤a Region. We recorded the vascular plant composition in twelve fragments of different size, perimeter/area, elevation level and evidence of human degradation (logging, fire, cattle faeces). Based on these variables we performed a fragmentation and a degradation index. Pearson correlations were used to analyze the relationship between all these variables. We found that fragmentation and degradation were positively correlated, and each of them decreased with altitude. Furthermore, fragmentation and degradation affected native and exotic species richness in different ways. Invasion was enhanced by both fragmentation and degradation, and as consequence of the altitudinal patterns of these human-caused disturbances, invasion seems to occur mainly in lowlands. In turn, native species richness decreased with fragmentation, and it was not related to degradation nor altitude. Impactos humanos tales como la fragmentaci車n y degradaci車n de bosques pueden tener fuertes efectos en las comunidades de especies vegetales nativas y ex車ticas. Adem芍s, perturbaciones antr車picas ocurren principalmente en menores altitudes produciendo mayores grados de fragmentaci車n y degradaci車n que en mayores altitudes. La invasi車n de plantas ex車ticas deber赤a ser mayor en bosques m芍s fragmentados o degradados y, por lo tanto, en menores altitudes dentro de un tipo de bosque o piso altitudinal. En cambio, la riqueza de especies nativas deber赤a ser negativamente afectada por la fragmentaci車n y degradaci車n, encontr芍ndose mayor riqueza en mayores altitudes dentro de un tipo de bosque determinado. En este trabajo evaluamos estas hip車tesis en un bosque templado andino de la Regi車n de la Araucan赤a, Chile. Registramos la composici車n de plantas vasculares en doce fragmentos de diferente tama o, raz車n per赤metro/芍rea, altitud y degradaci車n antr車pica (cortas, incendios, fecas de ganado). En base a estas variables construimos un 赤ndice de fragm
%K Fragmentaci車n
%K degradaci車n
%K gradiente altitudinal
%K invasi車n
%K diversidad vegetal
%K Fragmentation
%K forest degradation
%K elevation gradient
%K invasion
%K plant diversity
%U http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-66432011000200006