An evaluation of the afforestation outcome of six tree species in more than 40 years in Meng-shan Mountain, Shandong Province, China

Abstract

Aims Vegetation restoration is always a key problem and primary objective in restoration ecology.Our objectives were to evaluate forest restoration and reconstruction in Mengshan Mountain,including the impact on plant diversity of using different tree species in afforestation,and to select species for afforestation,in order to provide the basis for regulation and prediction of forest vegetation restoration and reconstruction in the Yimeng Mountain Area.Methods Six kinds of major artificial forest over 40 years in age were selected for study using a typical sampling method.Species richness,Shannon-Wiener diversity index,Simpson diversity index and Pielou evenness index were used to evaluate species diversity of the tree,shrub and herb layers.Analysis of tree diameter-class distribution was applied in determining the type of development of the plant.Important findings Each of the four indexes indicated that Pinus densiflora,Quercus variabilis,P.thunbergii,Larix kaempferi and Robinia pseudoacacia have better outcomes in afforestation and P.tabuliformis has relatively poor outcomes.In the tree layer,the four diversity indices of the P.tabuliformis artificial forest community were significantly different from those of P.densiflora,Q.variabilis,P.thunbergii,L.kaempferi and R.pseudoacacia artificial forest(p 0.05).In terms of diversity,shrub layer tree layer herb layer,and the differences were significant(p 0.01).There are 29 expansive species,3 seclusive species,9 enhancing invasive species and 11 randomly invasive species.Pinus densiflora and P.tabuliformis had great difficulty in population regeneration,and L.kaempferi had no seedlings.Shrub layers and herb layers may be the key factors hindering the natural regeneration of coniferous forest.Fifteen kinds of species for afforestation of Mengshan Mountain have been screened,including seven species for early afforestation(A) and eight for afforestation(B).Two types of A1(constructive species) are P.densiflora and P.tabuliformis.Five types of A2(companion species) are Dalbergia hupeana,Fraxinus rhynchophylla,Cerasus serrulata,Albizia kalkora and Carpinus turczaninowii.Two types of B1(constructive species) are Q.variabilis and Q.acutissima.Six types of B2(companion species) are Sorbus alnifolia,Q.dentata,Diospyros lotus,Celtis bungeana,Celtis koraiensis and Lindera obtusiloba.