The work was supported by Science and Technology Plan Projects
of Zhejiang Province [grant numbers 2019C02024].
Abstract: Satyrium is an endangered and rare genus of
plant that has various pharmacodynamic functions.
The prediction of potentially
suitable habitat of Satyrium species and to analyze their
changes, the model MaxEnt niche was applied; furthermore, the receiver
operating characteristic curve was applied to analyze accuracy. The
results provided an available reference for implementation of long-term
conservation and management approaches for the species. Under the
current climatic conditions, the area of the total suitable habitat forSatyrium ciliatum (S. ciliatum ) in China is 32.51 ×
104 km2, the total suitable habitat
area for Satyrium nepalense (S. nepalense ) in China is
61.76 × 104 km2, and the area of the
total suitable habitat for Satyrium yunnanense (S.
yunnanense ) in China is 89.73 × 104km2. The potential suitable habitat ofSatyrium is mainly distributed in Southwest China. The major
environmental changes influencing the geographical distribution ofS. ciliatum were temperature seasonality (Bio4), isothermality
(Bio3), and mean temperature of coldest quarter (Bio11).
The geographical distribution ofS. nepalense was mainly affected by environmental variables like
temperature seasonality (Bio4), isothermal environment (Bio3), and
precipitation of the coldest quarter (Bio19); and the geographical
distribution of the species S. yunnanense were mainly affected by
the environmental variables such as temperature seasonality (Bio4),
isothermality (Bio3) and lower temperature of the coldest month (Bio6).
The distribution range of Satyrium’s extended with global warming
increased, in both situations’ emissions of greenhouse gases with lower
concentration (SSP1-2.6) and the emission of greenhouse gases with
higher concentration (SSP5-8.5). According to the study, the
distribution of suitable habitat would shift with change to higher
elevated areas in the coming time.
Keywords: Satyrium , MaxEnt niche, the potential
suitable habitat, environmental variables.
Global warming is one of the crucial environmental problems facing the
world today (1). The global temperature has risen by about 1℃ in the
past century, especially in the past 30 years, causing some florae
species to move to higher altitude areas, as reported by the Fifth
Assessment Report (AR5) of the United Nations Intergovernmental Panel on
Climate Change (2). According to the different suggestions that the
future change in climate has an impact on the distribution range of
species, resulting in the loss of biodiversity and the endangered
species will be extinct (3). After climate change, the prediction of the
appropriate habitat of species was considered important in the future
(4). In research on the geographical distribution range of plants
affected by climate change, the species distribution model (SDM) uses
the distribution data of species and environmental variables in their
habitat to predict the basic niche of species. These data are combined
with environmental data in different periods for simulating the
potential distribution areas of species in those periods (5). Among many
SDMs, the maximum entropy model (MaxEnt) has the advantages of fast
modeling, wide use and high accuracy, and stability even with a small
sample size (6, 7). It can better anticipate the possible distribution
of species compared with other SDMs (8).
Satyrium (Orchidaceae) is rare and endangered plant genus with
about 92 species, mostly found on continents of Africa, 5 species found
in Madagascar and 4 species are found in Asian countries (9). Just 3
species are found in China alone, namely, Satyrium ciliatum(S. ciliatum ), Satyrium nepalense (S. nepalense ),
and Satyrium yunnanense (S. yunnanense ) (10).Satyrium is also used for traditional herbal medicinal purposes;
such as the traditional healthcare centers in India used the tubers ofS. nepalense to make energy tonics and it is mostly used for
curing different types of fevers.
The number of Satyrium resources has been rapidly diminishing.
Its population has a fragmented distribution and is in a rare and
endangered state. It is facing extinction because of the value of herbal
medicine and the serious deterioration of the ecological environment in
recent times (9). The 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 a quickening of the rate of
species extinction. Therefore, it is necessary to adequately understand
the changing trends of the geographical distribution of species under
the conditions of climate change and to develop relative protection
strategies.
The diversity of Satyrium species were predicted by employing the
MaxEnt model:
(1) In current climatic conditions, the geographical diversity ofSatyrium species in China were studied, and relationship between
these distributions and environmental changes were studied. The main
environmental variables limiting their potential geographically
diversity was outlined.
(2) The potential geographical distribution and shifting trend of the
centroid of suitable areas in China were predicted under the scenario of
future climate change. To offer a scientific foundation for the
appropriate protection and utilization of Satyrium, the conceivable
geographical distribution, dynamic change features, and affecting
environmental elements in China under different climate conditions were
defined.