%0 Journal Article %A 3 %A 2 %A 2 %A 3 %A HOU Yuan-rui1 %A TAN Yi-bo1 %A HE Qin-fei1 %A 2 %A 2 %A 2 %A 3* %A ZHENG Wei1 %A 2 %A 3 %A 3 %A 3 %A PENG Yu-hua1 %A HE Feng1 %A SHEN Wen-hui1 %A 2 %A 3 %T Effects of canopy structure on understory vegetation in shelterbelt forests along the middle and upper reaches of Pearl River. %D 2016 %R %J Chinese Journal of Ecology %P 3148-3156 %V 35 %N 12 %X Understory vegetation of shelterbelt forest is important for water conservation, soil retention and ecosystem service enhancement. Five types of shelterbelts along the middle and upper reaches of Pearl River in Du’an, Guangxi were observed, including Eucalyptus robusta forest, Zenia insignis forest, Pinus massoniana forest, Pinus massoniana + Schima superba mixed forest and Cyclobalanopsis glauca forest, to study the effect of canopy structure and understory light on vascular species composition and regeneration. We used DMCLX5 and external Nikon FC-E8 fisheye lens to record canopy openness (CO), leaf area index (LAI), transmitted direct solar radiation, transmitted diffuse solar radiation and transmitted total solar radiation, and investigated relations among the indexes and their effects on the understory vegetation. The results showed that: 1) P. massoniana + S. superba mixed forest was more conducive to maintaining shrub layer diversity than other pure forests; 2) The canopy structure indexes (CO and LAI) were significantly correlated with understory light indicators (P<0.001), and canopy structure had a greater effect on transmitted diffuse solar radiation than on transmitted direct solar radiation; 3) CO and understory light were significantly negatively correlated to shrub layer species richness (S) and Shannon index (H) (P<0.001), suggesting that higher light in understory did not facilitate the maintenance of the shrub layer diversity. We concluded that canopy structure was a key factor affecting the shrub diversity and regeneration, and the interspecific competition between shrub layer and herb layer might be another important factor. To improve ecosystem services of the forests, we recommend planting associated tree species to increase canopy density, promoting the development of shrub layer species. For herb layer improvement, single dominant herb species should be moderately reduced in coverage to provide space for other species’ regeneration. %U http://www.cje.net.cn/EN/abstract/article_22528.shtml