BCI Soil Survey

1.2 Soil – Related Ecological Research on BCI

BCI is the most intensively researched tropical forest in the world (Ocana et al. 1988; Rubinoff & Leigh, 1990).  Work done on BCI has greatly contributed to current understanding of the ecology of neotropical moist forests and of the tropical forest biome in general.  There are overviews of scientific investigations and publications on BCI in Leigh (1999) and Leigh et al. (1996).

One of the activities pioneered on BCI was the setting up of large long-term ecological research (LTER) plots in tropical forests.  There is now a pantropical network of 16 such plots, coordinated by the Center for Tropical Forest Science (CTFS), an entity within STRI, and, for the nine Asian plots, by the Arnold Arboretum of Harvard University.  The plots are large (ideally 50 ha, with up to a third of a million stems on each), so that they contain statistically robust populations (ideally > 100 stems) of all but really rare species.  The freestanding vegetation (i.e. excluding climbers) down to 1 cm diameter at reference height (1.3 m above ground level or 0.6 m above the highest buttress) is initially inventoried and then monitored at five-year intervals, so that the life history of every tree in the forest can be traced from young sapling to death and disappearance. 

The first CTFS plot was established on BCI, and the CTFS standard methodologies were pioneered, tested and codified on the BCI 50 ha LTER plot (Condit, 1998).  The monitoring period for BCI is longer than for any other CTFS plot, with the initial inventory in 1981-2, and the sixth quinquennial re-census in 2005.  This enables analyses of the dynamics of the forest on BCI to extend over decades rather than just years, and a picture of the effects of medium term climatic variations on tropical forest is starting to emerge (Condit et al.1995 & 1996; Chave et al. 2003).
One of the themes that consistently interests plant ecologists on BCI, and in CTFS and in other tropical forests, is the origin and maintenance of high tree species diversities at local, regional and biome scales.  Possible influences and determinants include:

(Leigh et al., 2004).

In general, less importance has been accorded to abiotic niche specialisation on BCI than in some Asian forests.  This is true for island–wide studies (e.g. Knight, 1975; Svenning et al., 2004), and on the BCI 50 ha LTER plot (e.g. Harms et al., 2001).

Research into the possibility of abiotic niche specialisation cannot progress far without detailed characterisation of the physical environment, including soils.  Soil data for BCI are limited.  Edaphic habitats have hitherto been characterised as topographic classes, and by topographic attributes, such as elevation, slope angle, and hydrological indices.  BCI soils have so far been differentiated only as generalised classes (Brenes-Arguedas & Coley, 2005; Croat 1978; Harms et al., 2001; Knight, 1975; Svenning et al. 2004).

 

next   1.1 Barra Colorado Island  1.3 Aims of BCI soil survey   next