Forestry

Demography

Ecology

Biology

Forest structure

Diameter at breast height

Mathematics

Geography

Population

Sociology

Geometry

Population structure

Pyramid (geometry)

Subtropics

Canopy

Acta oecologica. Oecologia applicata

Population structure based on diameter measurements of individuals of five common and economically important tree species, Manglietia insignis (Wall.) Bl., Myrica esculenta Buch. Ham., Quercus dealbata L., Q. griffithii Hk. and Schima khasiana Dyer., was studied in the disturbed and protected (undisturbed sacred grove) stands of the subtropical wet-hill forests of Meghalaya, north-east India. The diameter structure of the populations putting small diameter individuals at the base of the diameter pyramid was drawn. The population structure of these species was like an inverted pyramid (i. e., large diameter individuals were greater in number than the small diameter individuals) in the undisturbed stands, whilst in the disturbed stand, except for Q. dealbata the diameter structure was upright pyramidal (i. e. small diameter individuals were more numerous than the large diameter individuals). Seedlings of the five species constituted C. 40 % of the populations in the disturbed stand compared to C. 10 % in the protected stand. The sapling populations were also larger in the disturbed than in the protected stand. The proportion of individuals having thick trunk (designated as trees) was, however, greater in the undisturbed stand. The diameter structure of populations of all tree species in a stand considered together was upright pyramidal in shape in the disturbed and inverted pyramidal in the protected forest. The difference in diameter structure and its implications for forest management has been discussed in light of prevailing conditions in the two types of forest.

Population structure of some tree species in disturbed and protected subtropical forests of north-east India