Predicting the Potentially Suitable Climate Areas for Four Varietas of Toona ciliata, in Yunan Province by Maximum Entropy (MaxEnt) Model

PurposeTo predicting the potentially and climate suitable areas of the valuable timber species, Toona ciliata var. henryi, T. ciliata var. pubescens, T. ciliata var. ciliata, and T. ciliata var. yunnanensis in Yunnan Province, and also examining the influences of environmental factors on their distribution pattern, as well as providing theoretical basis for resource protection, introduction, and large-diameter timber cultivation of T. ciliata.

MethodsThe current distribution sites of four T. ciliata varietas and the corresponding altitude variables, 19 bioclimatic factors were applied to predict the potentially and climate suitable areas of T. ciliata varietas in Yunnan Province by a maximum entropy (MaxEnt) model.

ResultsThere were a high reliability and accuracy (AUC>0.9) in the MaxEnt models of four T. ciliata varietas. The influencing factors and the contribution of specific environmental factor were different among four T. ciliata varietas. The first restriction factors in the suitable establishment areas were the isothermality with 66.2% contribution, minimum temperature of the coldest month with 49.0% contribution, standard deviation of temperature seasonal variation with 61.4% contribution, and annual mean temperature with 63.6% contribution for T. ciliata var. ciliata, T. ciliata var. pubescens, T. ciliata var. henryi, and T. ciliata var. yunnanensis, respectively. Their second restriction variables were standard deviation of temperature seasonal variation with 18.4% contribution, annual precipitation with 18.7% contribution, precipitation of the driest month with 15.2% contribution, and the isothermality with 15.8% contribution, respectively. The potential areas of predicted distribution were 7.40×10⁴, 10.82×10⁴, 20.31×10⁴, and 22.58×10⁴ km² for T. ciliata var. henryi, T. ciliata var. yunnanensis, T. ciliata var. pubescens, and T. ciliata var. ciliat.

Concludings According to the magnitude of the predicted areas, the order of species protection priority are T. ciliata var. henryi, T. ciliata var. yunnanensis, T. ciliata var. pubescens, and T. ciliata var. ciliata. This finding would promote the resource protection, introduction, and large-diameter timber cultivation of T. ciliata varietas in the different regions under the principle of selecting suitable species for sites.