IMBIV   05474
INSTITUTO MULTIDISCIPLINARIO DE BIOLOGIA VEGETAL
Unidad Ejecutora - UE
artículos
Título:
Livestock reduces juvenile tree growth of alien invasive species with a minimal effect on natives: a field experiment using exclosures
Autor/es:
RENISON D.; AGUILAR R.; CAPÓ E.A.
Revista:
BIOLOGICAL INVASIONS
Editorial:
SPRINGER
Referencias:
Lugar: Berlin; Año: 2016 vol. 18 p. 2943 - 2950
ISSN:
1387-3547
Resumen:
Many alien invasive tree species were originallyintroduced to their non-native ranges for use in forestry and as urban trees.These alien species were selected for their fast growth and not necessarily forpossessing mechanisms which deter browsing. Instead,many tree species native tosemiarid areas of the world evolved mechanisms which deter browsing, presumablyat the cost of slower growth. In a semiarid rangeland we observed thatlivestock exclusion greatly promoted the growth of juveniles of several alienspecies but not of native species, and we hypothesized that this increase in growth ofaliens was due to livestock preference for alien and not native trees. With theobjective of quantifying our observations and understanding the mechanismunderlying the increased growth rates of alien juvenile trees under livestock exclusion,we assessed growth and browsing levelsin juveniles of two alien invasive and four abundant native tree species withinthree parcels where livestock was excluded and three parcels with livestock at0.20 cattle equivalents.ha-1. Alien species grew around four-foldfaster under livestock exclusion than with livestock and, as predicted,received five times more browsing than natives. Instead, native species did notsignificantly increase their growth rate with livestock exclusion. The resultssupport our hypothesis and the implications for management would be thatstocking paddocks with livestock to browse existing alien juveniles andre-growth of felled adults should be effective in delaying invasions of treesused for forestry without significantly affecting the growth of the mostabundant native trees.