Tropical rain forest fragmentation and its ecological
and species diversity changes in southern Yunnan
H. ZHU*, Z.F. XU, H. WANG and B.G. LI
Xishuangbanna Tropical Botanical Garden, The Chinese Academy of Sciences, Xue Fu Road 88,
Kunming 650223, Yunnan, P.R. China; *Author for correspondence (e-mail: zhuh@xtbg.ac.cn; fax:
þ86-871-5160916)
Received 2 December 2002; accepted in revised form 7 May 2003
Key words: Ecological factors, Rainforest fragments, Southern Yunnan of China, Species diversity
Abstract. Three fragmented rain forests and one primary forest in southern Yunnan were plotted. The
microclimate and soil conditions of these forests were also studied. The following conclusions were
drawn: (1) The microclimatic differences between inside and outside forest are less in the fragmented
forests than in the primary forest, which indicates that the buffer effects to climatic change have been
reduced in the fragmented forests. The soil has deteriorated to some extent due to forest fragmentation.
(2) In species composition, especially the abundance of some species and the dominant ranks of some
families have changed with fragmentation. Barringtonia macrostachya, the most dominant species in the
control primary forest, disappeared from the fragmented forests, while Antiaris toxicaria, which is a
characteristic but not dominant species in the primary forest, is dominant in fragmented forests. (3) The
total number of species per plot was reduced in the fragmented forests and the more seriously disturbed
the fragment was, the more the species richness diminished. (4) In life form spectra, the liana and
microphanerophyte species increased, but epiphyte, megaphanerophyte, mesophanerophyte and cha-
maephyte species decreased in the fragmented forests. (5) The plant species diversity is generally lower
in the fragmented forests than in the primary forest, although for some life forms it could be higher. (6)
The tree species with small populations could be lost first in the process of rain forest fragmentation. (7)
The heliophilous or pioneer tree species increased and the shade-tolerant species were reduced in the
fragmented forests.
Introduction
Studies on the biodiversity changes of fragmented tropical rain forests have been
undertaken independently in many tropical areas of the world since the 1980s
(Diamond et al. 1987; Laurance 1991, 1994; Newmark 1991; Williams-Linera
1992; Fonseca de Souza and Brown 1994; Kattan et al. 1994; Daily et al. 1995;
Murcia 1995; Turner 1996; Fox et al. 1997; Laurance and Bierregaard 1997;
Oliveira-Filho et al. 1997; Laurance et al. 1998a, b). The most representative are
those in Manaus, Brazil (Lovejoy et al. 1986; Klein 1989; Bierregaard et al. 1992;
Fonseca de Souza and Brown 1994; Malcolm 1994, 1997; Camargo et al. 1995;
Ferreira and Laurance 1997; Benitez-Malvido 1998; Laurance et al. 1998a, b).
Many interesting results have been obtained. It is commonly accepted that species
richness reduces with the fragmentation of tropical forests (Lovejoy 1986;
Bierregaard 1992; Chittibabu and Parthasarathy 2000). The smaller the fragments
are, the less species richness the fragments display (Newmark 1991; Leigh et al.
# 2004 Kluwer Academic Publishers. Printed in the Netherlands.
Biodiversity and Conservation 1355–1372, 2004.
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