ECOLOGICAL STUDIES ON TILE SYMBIOSIS OF TER ITOMYCES ...

2*1,1 VEGETATION
2.1 DESCRIPTION OF STUDY AREAS
The fieldwork associated with this project was carried out in and
around Holwa Agricultural Research Stations in Niger State, Nigeria at
9018IN9 50046E. Mokwa lies close to the boundary of the Southern
Guinea savanna vegetation zone of West Africa (Figure 2.1.1).
The sites in which work wan carried out include
(1) Prim. -x= savanna woodland. This was mainly at zugurmal 15 km
northwest of Ik)kwa (Figure 2olo2), and as far as could be determined
had never been cultivated, The natural vegetation was closed savanna
woodland of semi-deciduous trees 12-15 m high with tall perennial
grasses uP to 2-3 m high (Wood and Johnson 1978)e The most common
trees were 3 Caesalpiniaceous legumes, Afzelia africana Smo, Burkea
africana. Iloo1c. and Detarlum microcaum Guille and Per. (Collins 1977)e
The grasses were composed mainly of Andron2gon nayanus Kunth.
Eragrostis trenula Olochat
ex Steud) and Ilyparrhenia dissoluta Noes.
ex Steud (Wood et al. 1977)9 Annual fires in the dry season burned
most of the grass, leaf litter and killed leaves-on trees,
(2) Seconda! Z woodlands Theno areas around tho Agricultural
lResearch'Station vere cleared during the 1949-1953 Colonial Development
Corporations Groundnut Scheme (Baldwin 1957). Piegrowth was prevented
by cutting until 1959 after which time regrowth was unchecked* The
species present were those In (1) but without largo trees.
(3) Experimental plots. * This area (Figure Zel,, Z) had been
cleared and regenerated as Wo In 1973 it was cleared again and 12
plots established in the 1974 growing season
(Wood ot ^1,1980). Two
j
35.