海南霸王岭山地原始林与伐后林中木质藤本对支持木的选择

通过对海南霸王岭热带山地原始林与伐后林中树木及其攀附木质藤本的调查,研究原始林与伐后林中木质藤本对支持木的选择性。结果表明:1)6科优势树木中附藤率最高的是野牡丹科(Melastomataceae),附藤率最低的科,原始林中是山矾科(Symplocaceae),伐后林中是茜草科(Rubiaceae)。2)原始林中,谷木(Memecylon ligustrifolium)与线枝蒲桃(Syzygiumaraiocladum)的附藤比率和每木藤本数均高于样地平均水平;三角瓣花(Prismatomeris tetrandra)和龟背灰木(Symplocosandenophylla)的附藤比率均低于样地平均水平,而每木藤本数与样地平均水平之间没有显著差异。伐后林中,谷木的附藤比率和每木藤本数高于样地平均水平;九节(Psychotria rubra)的附藤比率和每木藤本数低于样地平均水平。3)杜仲藤(Parabariummicranthum)的主要支持木是谷木,夜花藤(Hypserpa nitida)的主要支持木是线枝蒲桃。研究表明,木质藤本对支持木在科和种水平上都具有选择性,因此木质藤本会对树木造成不对称影响,进而影响森林的结构和动态。

Liana-host tree associations in the tropical montane primary forest and post- harvest forest of Bawangling, Hainan Island, China

In the present study, the associations between trees and lianas were investigated along four ridge transects in primary forest and post-harvest forest in tropical evergreen mountain rain forest in Bawangling Nature Reserve, Hainan Island. The results showed that, in primary forest, Melastomataceae had a higher proportion of trees with lianas than the other five dominant families while Symplocaceae had a lower proportion. However, the percentage of trees with lianas showed no significant overall difference among six dominant families (P = 0.09). In post-harvest forest, Melastomataceae had a higher proportion of trees with lianas as well, but Rubiaceae had the lowest proportion. The percentage of trees with lianas showed a significant overall difference among six dominant families (P < 0.01). At the species level, in primary forest, Memecylon ligustrifolium and Syzygium araiocladum both had a significantly higher proportion of trees with lianas, while Prismatomeris tetrandra and Symplocos crassifolia both had a lower proportion. M. ligustrifolium, S. araiocladum and Symplocos laurina were infected by lianas more than other host tree species, however, the number of lianas per tree were not significantly different from the average level of plots. In post-harvest forest, M. ligustrifolium, had a higher proportion of trees with lianas and Psychotria rubra had a lower proportion. M. ligustrifolium, S. araiocladum and Acronychia pedunculata were infected by lianas more than other host tree species, but P. rubra was rarely infected by lianas. In primary forest, M. ligustrifolium was the dominant host tree species, and four liana species selected them as their main host. Hypserpa nitida and Parabarium micranthum had obvious selectivity to the host tree species in five main liana species. In post-harvest forest, M. ligustrifolium and S. araiocladum were the dominant host tree species, and two liana species selected M. ligustrifolium as their main host, while two liana species selected S. araiocladum as their main host trees. H. nitida, P. micranthum, Smilax amaurophlebia and Smilax china had obvious selectivity to the host tree species in seven main liana species. In two forest types, P. micranthum and H. nitida infected the same host tree species. M. ligustrifolium was infected more by P. micranthum and S. araiocladum more by H. nitida. This study showed that the percentage of trees with lianas varied among families and species. Lianas affect host trees that belong to different families and different species in different ways. In conclusion, trees could suffer from asymmetric influences from the interference of lianas, which would affect forest structure and dynamics during forest succession.