STRUCTURAL, FLORISTIC AND EDAPHIC ATTRIBUTES OF THE GRASSLAND SHOLA FORESTS OF ERAVIKULAM IN PENINSULAR INDIA

The high elevation shola-grassland vegetation types of the Western Gha ts apparently remained in a stable equilibrium for many decades, imply ing that both vegetational types are highly developed and attained sta bility under the same climatic regime. Several authors considered thes e two distinct vegetation formations occuring in juxtaposition, as cli max formations. According to the Clementsian view of climatic climax, however, two distinctly different vegetation types cannot form climati c climaxes under the same regional climate. Possibly some edaphic or b iotic factors are responsible for rendering stability to the grassland s in this system. We tested the following three hypotheses in this con text. ( 1 ) The physico-chemical properties of the soil such as depth, organic matter, nutrient status and water holding capacity are more f avourable in the depressions than in the exposed surfaces, which in tu rn might be responsible for the development of the woody vegetation in the depressions. (2) The shola forests exhibit similar structural att ributes and a higher floristic diversity compared with the medium and low elevation wet evergreen forests of the Western Ghats region. (3) T he shola trees are characterised by a low regeneration capacity, thus probably making it a shrinking resource base. With its characteristic deep fertile soil and high moisture holding capacity, the shola forest s may remain in the same steady climax state, provided anthropogenic a nd other catastrophic disturbances do not destroy them. The grasslands were, however, characterised by generally shallow soils, low water ho lding capacity and low site nutrient capital. Hence, the assumption th at grasslands are steady state vegetations maintained by edaphic facto rs, holds good. Structural and floristic elements of the shola forest revealed a very high floristic richness and diversity, probably the hi ghest in the Western Ghats region. A total of 942 stems of at least 10 cm girth at breast height (GBH) and belonging to 5 3 species were enc ountered in the 5000 m2 sampling area (basal area 48 M2 ha-1). Contrar y to the widely held dogma that shola forest does not possess adequate regeneration potential, the present study reveals that under the fore st cover, profuse regeneration of almost all of the overstorey species occur. However, regeneration characteristics were different along the margins and in open grasslands, possibly as a result of differences i n ecological conditions.