| China is one of the largest forest producer country in Asia and the P.massoniana has been widely planted for timber production and habitat restoration.Evaluation and monitoring of forest structure,diversity,and biomass carbon dynamics are essentials for effective forest biodiversity and carbon conservation.Forest structural diversity is expected to provide potential tool for forest management planning and the rapid and accurate estimation of large-scale forest structural attributes.It also provides an important base for the development of sustainable forest management planning.Forest are important in the global carbon cycle,and necessary to estimate forest above ground biomass and above carbon storage,which are the basis for studying the structure and function of forest ecosystem.In this study,first,it was imperative to evaluate the effect of altitudinal gradient in P.massoniana forest attributes in Guangxi Zhong Autonomous region,South China.We estimated the forest structure,species diversity,growing stock characteristics and allometric regression models used to estimate biomass carbon.The data was collected from Inventory data of woody stem of 174 permanent systematic sampling field plots with a size of 400 m2.In the 2nd study,we further studied the effect of altitudinal gradient on P.massoniana forest attributes to investigated the variation pattern of basal area,density and biomass carbon of P.massoniana along altitudinal gradients?elevation,slope and slope aspects?.The data was collected from inventory data with a permanent circular sample plot,the size was 400 m2.The altitudinal gradients were further categorized into sub classes namely;elevation?ELV-1 ELV-2,ELV-3?,slope?slope-1,slope-2,slope-3?,and slope aspects(E?East?,NE?North East?,N?North?,W?West?,NW?North West?SE?South East?,S?South?and SW?South West?.The main conclusions are as follows;1.We found a total of 198 species belonging to 51 families,and 128 genera were found.The forest was classified into three different diameter classes,?Class 1,9.63±0.21.Class 2,14.30±0.17 and Class 319.95±0.40?the average diameter varied significantly between the different diameter classes.The highest mean diameter was recorded in the class-3,while the lowest was found in the class-1.For growing stock volume,the diameter of trees at breast height and height was measured in each sample plot,and then measured biomass carbon.The results of different diversity indices showed a greater species variation across the forest.Furthermore,different tree attributes were recorded for forest structure.In this regard,the mean tree height was 10.3 m,while the mean basal area was 5.94 m2 ha-1.The mean growing stock volume was 104.14 m3ha-1,and the average biomass carbon was 110.36Mg ha-1.Among the dominant tree species,the maximum importance value index?IVI?14.81%and basal area?BA?17.3±3.03 m2 ha-1 was recorded for P.massoniana.While the maximum growing stock volume?GSV?116.4±20.2 m3 ha-1 and biomass carbon 114±18.3 Mg ha-1 were recorded in the Styrax subniveus.Our results also highlighted that the basal area is a strong predictor of growing stock volume and biomass carbon compared to diameter and height.Moreover,the correlation between biomass carbon and diversity indices indicated a weak positive correlation,which provided the insight that high-value carbon-diversity forest can be achieved.2.The results showed that along elevation gradients,the basal area was highest at ELV-3,the tree biomass increased with increasing elevation,while density was highest on ELV-1.In case of slope range,the basal area,biomass carbon was highest at slope-3,while and density was maximum at slope-2.The slope aspects also showed different patterns of variation,i.e.,the highest density was calculated in North aspects,while the basal area and biomass carbon showed highest value on North West.These findings provide a sound base for estimating the variation in forest attributes with respects to altitudinal gradients. |
PDF Full Text Request