Tree species diversity along altitudinal gradient on southeastern and northwestern slopes of Mt. Huanggang, Wuyi Mountains, Fujian, China

Abstract

To investigate altit udinal changes of t ree species biodiversity and community st ruct ures , we investigated 30 plot s on t he sout heastern slope and 13 plot s on t he nort hwestern slope of Mt . Huang2 gang , Wuyi Mountains , Fujian Province. We recorded 151 t ree species f rom 42 families and 73 genera on t he sout heastern slope , and 102 t ree species f rom 32 families and 54 genera on t he nort hwestern slope. There was no significant difference of t ree species composition between t hese two slopes. The number of families , genera and species in t he t ree layer decreased as altit ude increased. The richest families , genera and species were recorded at t he altit udes between 800 -1000 m a. s. l. on t he sout h2 eastern slope , and between 1500 -1600 m a. s. l. on t he nort hwestern slope. The species diversity of t ree layer on t he nort hwestern slope was higher t han t hat of t he sout heastern slope f rom 1200 -1800m a. s. l. . Shannon2Wiener index ( H ) correlated negatively wit h elevation on bot h slopes. S renson in2 dex ( IA c) varied in t ransitional zones between vegetation types , and was lowest at t he ecotone be2 tween evergreen broad2leaved forest s and mixed coniferous and broad2leaved forest s. Considering com2