Kim Hy Proposed Nature Reserve - Frontier-publications.co.uk

3.4 Discussion
3.4.1 Description of vegetation types found within the regeneration and
administrative zones (II and III) of Kim Hy P.N.R.
The north and north-eastern region of the proposed nature Reserve, which comprise the
regeneration and administrative areas and which are to a greater extent excluded in the
proposal by FREC, are comprised of a patchwork of vegetation types, largely derivatives
of, or directly threatened by, human activity. The land-cover has been classified by FIPI
(1997) into various categories depending primarily upon level of human impact and
potential for regeneration or rehabilitation. Aside from hill cultivation and the relatively
extensive areas of paddy rice adjoining highway 279 and its associated settlements in
Luong Thuong and Lang San, the principle FIPI categories are summarised in Figure 3.5
overleaf. Much of the northern area is classified on FIPI maps as ‘non-permanent forest’,
indicating the mosaic of regenerative habitats, and which has been included in the
classification of ‘scrub with scattered trees’ in Map 3 of this report.
The areas of scrub with few or no trees are mainly in Luong Thuong and Lang San’s
northern and eastern areas as well as much of eastern An Tinh, which comprises the main
body of the administrative/service zone, i.e. much of the accessible east and south-east of
the P.N.R. This habitat is also found scattered in northern parts of Kim Hy commune
(sub-regions 172 and 165), and it is largely a consequence of previous slash and burn
practices of local populations during the 1980s and to a lesser extent the 1990s. It has had
little chance to regenerate and the ferralitic soil supporting it is typically dry and
exhausted, with little water retention capacity. This results in the many grassland species
growing there, such as Ormosia balansae and Psychotria sp., which regularly dry out in
the winter months. These areas also typically support herbaceous communities of
Mimosa, Crotalaria and Desmodium (Fabaceae). In some areas, this scrub savannah is
adjacent to areas of settlement, rice paddy and hill cultivation, and is currently serving as
fallow ground awaiting future cultivation, or as grazing for domestic ruminants (buffalo
and, to a lesser degree, cattle). In cases where grazing of ruminants is not regulated
(leading to over-grazing), grass species of low forage value such as Chrysopogon sp. and
Paspalum conjugatum tend to colonise. Invasions of inedible Imperata cylindrica and
Chromolena odorata more commonly invade when the pastures are not maintained
(Castella et al, 2001). In the FREC revised proposal’s south-western area in Bach Thong
district, degraded scrub land forms much of the land area bordering the poor forest and
the relatively extensive areas of hill cultivation in Cao Son commune, due to a historical
shortage of paddy land and lack of technical development in agriculture in that region,
which has led to the intensive use of the non-karst hillsides.
Frontier Vietnam Forest Research Programme Technical Report No.24. 29