TY - JOUR
T1 - Structural features of fragmented woodland communities affect leaf litter decomposition rates
AU - Hastwell, Graeme T.
AU - Morris, E. Charles
PY - 2013
Y1 - 2013
N2 - Disruption to the physical structure of plant communities by habitat fragmentation can change microclimates, so leaf litter decomposition rates, being dependent on temperature and moisture, may also be affected. Similarly, smaller-scale structural features of plant communities can modify microclimates, and so may produce distinctive spatial patterns in decomposition rates. We investigated the effects of three types of structural feature having the potential to alter litter layer microclimates: fragmentation-induced modification that diminishes with distance from remnant edges (edge-core); concentric zones of locally modified conditions imposed by individual trees (Belsky-Canham); and highly localised abiotic modification collectively imposed by herbaceous plants (ground cover). We conducted a litter bag experiment in woodland remnants, testing whether the observed spatial variability in litter decomposition was attributable to one or more of these three structural features. The data provided the strongest support for the Belsky-Canham hypothesis, and the least support for the ground cover hypothesis. However, the hypotheses were not mutually exclusive, for each explained a component of the observed variability not explained by either of the other two. Proximity to remnant edge, proximity to trees, canopy light penetration, and ground cover density each explained part of the observed variability between plots. Decomposition rates did not differ with remnant area per se, for the effects of fragmentation were weak, and differed with cardinal direction. In contrast, the effects of individual trees were much stronger, and accounted for most of the between-plot variability. We found that litter decomposition rates in small remnants are only weakly affected by fragmentation, and we consider that the contributions of small remnants to landscape-scale functioning warrant closer attention.
AB - Disruption to the physical structure of plant communities by habitat fragmentation can change microclimates, so leaf litter decomposition rates, being dependent on temperature and moisture, may also be affected. Similarly, smaller-scale structural features of plant communities can modify microclimates, and so may produce distinctive spatial patterns in decomposition rates. We investigated the effects of three types of structural feature having the potential to alter litter layer microclimates: fragmentation-induced modification that diminishes with distance from remnant edges (edge-core); concentric zones of locally modified conditions imposed by individual trees (Belsky-Canham); and highly localised abiotic modification collectively imposed by herbaceous plants (ground cover). We conducted a litter bag experiment in woodland remnants, testing whether the observed spatial variability in litter decomposition was attributable to one or more of these three structural features. The data provided the strongest support for the Belsky-Canham hypothesis, and the least support for the ground cover hypothesis. However, the hypotheses were not mutually exclusive, for each explained a component of the observed variability not explained by either of the other two. Proximity to remnant edge, proximity to trees, canopy light penetration, and ground cover density each explained part of the observed variability between plots. Decomposition rates did not differ with remnant area per se, for the effects of fragmentation were weak, and differed with cardinal direction. In contrast, the effects of individual trees were much stronger, and accounted for most of the between-plot variability. We found that litter decomposition rates in small remnants are only weakly affected by fragmentation, and we consider that the contributions of small remnants to landscape-scale functioning warrant closer attention.
UR - http://handle.uws.edu.au:8081/1959.7/531135
U2 - 10.1016/j.baae.2013.03.002
DO - 10.1016/j.baae.2013.03.002
M3 - Article
SN - 1439-1791
VL - 14
SP - 298
EP - 308
JO - Basic and Applied Ecology
JF - Basic and Applied Ecology
IS - 4
ER -