The Potential Distribution Of Seven Woody Oil Plants In China Under Climate Change

Forest-based biodiesel is a type of bioenergy that has a good potential for development due to its features such as easy to convert,easy to utilize,and "does not compete with crop production".To develop forest-based biodiesel,suitable planting areas need to be selected.Woody oil plants normally grow for a long time and have a long fruiting time.Therefore,planning of forest-based biodiesel should consider areas that are suitable distribution areas both for now and future climates.At the same time,some woody oil plants have the characteristics such as strong adaptability to environments and high fecundity.It will be necessary to consider their potential to invade sensitive ecosystems and the associated negative impacts when growing them in large-scale.The risk of developing forest-based biodiesel may increase and ecosystems may be impacted negatively if one ignores these issuesIn this study,we first selected the suitable species distribution model and used it to predict the climate change impact on the potential distribution ranges of seven woody oil plants under two scenarios(RCP2.6 and RCP8.5).These species have been included in the National Forestry Biomass Energy Development Plan(2011-2020).The suitability of areas specified in the plan for developing these species is also studied.In addition,the possibility of invasion by these woody oil plants and the potential consequences was predicted.Main findings are as following(1)On selecting suitable models for predicting the climate change impact,all models performed well for seven tree species(AUC value higher than 0.9,TSS value higher than 0.8)except for SRE.However,there were differences in the estimated distribution tree species among the 10 models,especially at the borders of the distribution regions.The performance of ensemble model(AUC value 0.989-0.996,TSS value 0.882-0.958)was better than that of any single model(AUC value 0.762-0.991 TSS value 0.624-0.948).The ensemble model was then selected for predicting future distrbutions(2)The distribution ranges of the seven woody oil plants will shift to high latitudes under the future climate change.The shifting distances will be higher in the high-emission scenario(33 lan-195 km)than under the low-emission scenario(31 km-100 km).The potential distribution ranges of Pistacia chinensis,Sapindus mukorossi,Xanthoceras sorbifolium,Jatropha curcas,Sapium sebiferum,and Vernicia fordii will shrink in the south but the shrift to high latitude will offset the shrinkage.Overall,the distribution ranges of the six woody oil plants will increase by 0.3%to 12.9%.The distribution range of Swida wilsoniana will also shift to high latitude but reduction of its distribution at the south will be larger than the gain.The distribution range of S.wilsoniana will have a net loss of 10%-34%(3)For P.chinensis,S.mukorossi,S.wilsoniana,and J cuicas,the future potential distribution ranges overlap with the key development areas specified in National Forestry Biomass Energy Development Planning(2011-2020)by more than 80%.Among them,the future potential distribution ranges of P.chinensis,S.mukorossi,S.wilsoniana match with the planned growing areas as high as 93%.This high overlap indicates that the plan for these four woody oil plants is reasonable.For X.sorbifolium,the overlap between the potential distribution ranges and the planned key development areas is less than 75%.Therefore,when implementing the plan,attentions should be paid on the suitability of areas for X.sorbifolium under the future climate conditions(4)Among the seven species,J curcas has invasive potential.By 2050s and 2070s,it may pose threats to 11 and 14 protected areas under the low-emission scenario,respectively.It may spread to these protected areas.The affected area will be 2329 km2 and 2333 km2,respectively.It may affect seven and nine rare plants respectively,and three types of forest ecosystems.Under the high-emission scenario,it can pose a threat to 15 and 20 protected areas,respectively.Affected areas can reach 3312 km2 and 3453 km2,respectively.It may affect eight and nine rare plants respectively,and three types of forest ecosystems.