Effects of Shrub Islands Created by Rhodomyrtus tomentosa (Aiton) Hassk. on the Growth, Chlorophyll Fluorescence, and Chloroplast ultrastructure of Pine Seedlings in Degraded Land of South China

Abstract

AbstractIn degraded land of South China, the shrub Rhodomyrtus tomentosa (Aiton) Hassk. grows in aggregations and creates “shrub islands” with increased soil porosity and soil moisture but reduced soil nutrient content and light penetration. Previous researches indicated that these shrub islands can facilitate establishment of broad‐leaved tree seedlings. Because conifers are commonly used in reforestation projects, we determined whether shrub islands created by R. tomentosa also facilitate coniferous seedlings. Two common conifers, the native Pinus massoniana and the exotic Pinus elliottii, were transplanted on shrub islands and in open spaces (controls) between islands, and their growth, chlorophyll fluorescence, and chloroplast ultrastructure were investigated. Neither of the pine species was facilitated by the shrub islands. P. elliottii grew obviously higher in the open than under the R. tomentosa canopy, while P. massoniana was not facilitated by shrub islands, but it was not hindered either. The reduced growth of P. elliottii on shrub islands was associated with dilation of thylakoids in chloroplasts of mesophyll cells, lowered chlorophyll content, and reduced electron transport rate values. The results of this study indicate that P. elliottii should be transplanted in open spaces, and P. massoniana can be transplanted in open spaces or on shrub islands as part of restoration efforts, and the restoration technology of shrub island should be carefully used in degraded land of South China according to the species identity. Copyright © 2015 John Wiley & Sons, Ltd.