1 These authors contributed equally to this
work
Abstract: Satyrium is an endangered and rare genus of
plant that has various pharmacodynamic functions.
In this study, MaxEnt default
parameters were adjusted by the ENMeval package. Optimized MaxEnt models
were used in analyzing potential geographical distributions under
current and future climatic conditions (the 2050s and 2070s) and
dominant environmental variables influencing their geographic
distribution. The results provided reference for implementation of
long-term conservation and management approaches for the species. The
results showed the area of the total suitable habitat for Satyrium
ciliatum (S. ciliatum ) in China is 32.51 × 104km2, the total suitable habitat area forSatyrium nepalense (S. nepalense ) in China is 61.76 ×
104 km2, and the area of the total
suitable habitat forSatyrium yunnanense(S. yunnanense ) in China is 89.73 × 104km2 under current climatic conditions. The potential
suitable habitat of Satyrium is mainly distributed in Southwest
China. The major environmental variables influencing the geographical
distribution of S. ciliatum were isothermality (bio3),
temperature seasonality (bio4), and mean temperature of coldest quarter
(bio11). Environmental variables
such as isothermality (bio3), temperature seasonality (bio4), and
precipitation of coldest quarter (bio19) affected the geographical
distribution of S. nepalense ; and environmental variables such as
isothermality (bio3), temperature seasonality (bio4), and lower
temperature of coldest month (bio6) affected the geographical
distribution of S. yunnanense . The distribution range ofSatyrium was extended as global warming increased, showing
emissions of greenhouse gases with lower concentration (SSP1-2.6) and
higher concentration (SSP5-8.5). According to the study, the
distribution of suitable habitat will shift with a change to higher
elevation areas and higher latitude areas in the future.
Keywords: Satyrium , MaxEnt, potential suitable habitat,
environmental variables.
INTRODUCTION
Global warming is one of the crucial environmental problems facing the
world today (Bayer et al., 2021). The global temperature has risen by
about 1℃ in the past century, especially in the past 30 years, causing
some plant species to move to higher elevation
and higher latitude areas, as the
Fifth Assessment Report (AR5) of the United Nations Intergovernmental
Panel on Climate Change reported (Allen et al., 2014). Climate change in
the future will affect the distribution range of species, resulting in a
loss of biodiversity and the extinction of endangered species (Bellard
et al., 2012). After climate change, the prediction of suitable habitats
of species will be considered important in the future (Kumar et al.,
2021).
In research on the geographical distribution range of plants affected by
climate change, the species distribution model (SDM) uses distribution
data of species and environmental variables in species habitats to
predict the basic niche of species (Elith & Leathwick, 2009). These
data are combined with environmental data in different periods for
simulating the potential distribution areas of species in those periods
(Araújo & Peterson, 2012). Among
the many algorithms used in modeling species distribution, the maximum
entropy approach (MaxEnt) has demonstrated fast modeling, wide use, high
accuracy, and stability even with small sample sizes (Merow et al.,
2013; Pearson et al., 2007). It can better anticipate the possible
distribution of species compared with other SDMs (Phillips et al.,
2006). If the MaxEnt model and ArcGis predict potential species
distributions and biodiversity risks, relative strategies can be
established to reduce climate change’s negative influence on global
biodiversity.
S atyrium (Orchidaceae) is a rare and endangered plant
genus with about 92 species—mostly found in Africa, with five species
found in Madagascar alone, and four species found in Asian countries
(Mahendran & Bai, 2009). Only
three species have been found in China alone (all of which are endemic
in China) (Cun, 2005). They are mostly distributed throughout Southwest
China. Satyrium is also used for traditional herbal medicinal
purposes; for example, Greek medics used Satyrium tubers as
aphrodisiacs (Teoh, 2016). Traditional health-care centers in India use
the tubers of S atyrium nepalense (S. nepalense ) to
make energy tonics and cure different types of fevers (Mishra et al.,
2018). The number of Satyrium resources has been rapidly
diminishing. Its population has a fragmented distribution, and it is in
a rare and endangered status because of the value of herbal medicine and
the serious deterioration of the ecological environment in recent times
(Mahendran & Bai, 2009). Changes in climate will result in changes in
the biological phenology period. This in turn will result in changes in
the geographical distribution of species and an acceleration in the rate
of species extinction. Therefore, it is necessary to adequately
understand the changing trends of the geographical distribution of
species under climate change conditions and to develop relative
protection strategies.
Geographical distributions of three species from Satyrium genus
were predicted by employing the MaxEnt model: (1) In current climatic
conditions, the geographical distributions of Satyrium species in
China and the relationships between these distributions and
environmental variables were studied. (2) The main environmental
variables limiting their potential geographical distribution were
outlined. (3) The potential geographical distribution and shifting
trends of the centroid of suitable habitats in China were predicted in
future climate change scenarios. This study could offer a scientific
foundation for the suitable protection and use of Satyrium .