Date of this Version
Shiels, A.B. and L.R. Walker. 2013. Landslides cause spatial and temporal gradients at multiple scales in the Luquillo Mountains of Puerto Rico. In: G. González, M. Willig, and R. Waide, editors. Ecological Gradient Analyses in a Tropical Landscape. Ecological Bulletins. Blackwell Science, Oxford, U.K. 211-222.
Landslides represent one of the most severe disturbances in montane forests because the main consequence of their occurrence is loss or downslope redistribution of the majority of the above- and below-ground biomass. We examined among-landslide gradients (size, slope, aspect, age, elevation) on 142 landslides in the Luquillo Mountains, Puerto Rico, created by three storms in 2003–2004. We also examined within-landslide gradients (top to bottom, edge to center, successional development) by reviewing 20 yr of landslide data in the Luquillo Mountains. Landslide abundance and plant successional patterns do not closely reflect the elevation gradient that is characteristic of this mountain range, unlike many abiotic and biotic factors that do. Numerous physical gradients resulting from landslides, including soil nutrients, slope, age, and distance to edges and the base of a landslide, strongly influence colonization, growth, and survival of vegetation in the Luquillo Mountains. However, some gradients appear more pronounced than others, and the influence of each gradient on landslide recovery likely depends on both biotic responses to the net effects of multiple, overlapping interactions among gradients (e.g. soil slope and fertility) and the temporal and spatial scale at which attributes are measured. Therefore, even when the many gradients that influence plant colonization and landslide development are known, accurate predictions of species composition and time to forest recovery remain challenging.