1. Introduction
Climate is one of the most important factors in determining the distribution of species. The response of vegetation to climate change and the regional changes of plant distribution under the influence of climate are hot topics in biogeography, macroecology, and other disciplines (Y. Chen, Le, et al., 2022; O’Connor et al., 2020). With the continuous intensification of global warming, the global average surface temperature will rise by 1.1℃ to 6.4℃ by the end of the 21st century (P. Gao et al., 2023). Global warming is likely to significantly alter the structure and function of terrestrial ecosystems and increase the risk of species extinction (Thomas et al., 2004). To adapt to these changing conditions, plants can modify their ecological niche and distribution areas to match the new environment (Tang et al., 2021; Moran & Alexander, 2014). Climate change will pose significant uncertainty for future rational cultivation of medicinal plants (Higa et al., 2013). Blind introduction and expansion of medicinal plants without scientific guidance not only jeopardizes their quality but also misallocates resources (He et al., 2021). Long-term field introduction trials have traditionally been the most reliable way to identify suitable areas for herbal plant cultivation. However, it requires substantial resources and observation of several growth cycles (F. Li et al., 2019). Therefore, it is crucial to predict the potential suitable areas of medicinal plants under future climate change, which facilitates a better understanding of the cultivation potential of medicinal plants in new habitats.
Habitat loss caused by land use change will exacerbate the impact of climate change on species and ecological dynamics globally (Pant et al., 2021). Most studies that explore changes in plant species distribution and their future distribution only consider climate factors, with little attention paid to the synergistic effects of habitat and climate change (Sirami et al., 2017). However, in exploring changes in plant distribution, climate change-driven range expansion occurs in a spatial context. Yet each species’ habitat is unique. Thus, although many regions are suitable for survival, they may not be suitable as natural population habitats due to land use limitations. With increasing human activity, it is expected that 10% to 20% of natural grasslands and forests will be replaced by agriculture and urban infrastructure by 2050, leading to substantial habitat loss for most wild species (Y. Chen, Li, et al., 2022; X. Li et al., 2016). In this sense, it is necessary to explore the impact of land use change on species’ habitat. Integrating both climate and land use changes is essential for gaining a more accurate understanding of species’ distribution range under future climate and land use change.
Thesium chinense Turcz. is a semi-parasitic perennial herb of the genus Thesium in the Santalaceae. Its wild population is distributed in China, Japan, Korea, and other places (Chinese botanical society, 1988). As an important medicinal plant in China, dried whole grass of T. chinense has significant anti-inflammatory and analgesic effects. It is often used to prevent and treat all kinds of acute inflammation, so it has the reputation of a ”plant antibiotic” (Luo & Guo, 2011). In recent years, due to the deterioration of the ecological environment caused by excessive harvesting and the intensification of human activities, the population of T. chinense has sharply decreased throughout China and even disappeared in some ecological areas, seriously reducing the production of T. chinense (J. Gao et al., 2023). The supply-demand contradiction has become more prominent with the increasing demand from medicinal herb manufacturers (Luo et al., 2012). But at present, the system of artificial breeding of T. chinenseis not fully mature, which can not meet the rapid development of theT. chinense industry (J. Gao et al., 2023). Wild tending is a way to artificially or naturally increase the population in its native or similar environment according to the growth characteristics of the target species and its requirements for ecological environmental conditions. The significance of this method is to make the amount of resources available for people to collect and use, and to maintain the balance of the community (S. Chen et al., 2004, 2016). Therefore, planning a wild tending area for T. chinense is very important.
In this study, Biomod2 based ensemble species distribution model was used to investigate the relationship between population distribution and environmental factors in the complete ecological niche, and to predict and analyze the changes of population distribution under climate warming conditions in the century and the changes of natural habitat areas in the climate stable areas of China. In addition, we planned the wild tending areas of T. chinense in China based on ZONATION software (integrating future climate and land use change results). Furthermore, the synergistic effects of climate and land use change were considered, aiming to provide a more effective reference for the sustainable use ofT. chinense in China under the land use and climate change. The purpose of this study is: (1) To determine the main environmental factors limiting the distribution of T. chinense ; (2) To investigate the effects of climate change on the population distribution of T. chinense ; (3) To identify habitat changes within the climate-stable areas of T. chinense in China; (4) To plan wild tending areas for T. chinense in China and put forward management strategies.