How Fern and Fern Allies Respond to Heterogeneous Habitat— A Case in
Yuanjiang Dry-Hot Valley
Feng-Chun Yang 1, 2, 3, Chaya Sarathchandra4, 5, Jing-Xin Liu 6, Hua-Ping Huang7, Jian-Yong Gou 8, Ye Li7, Xiao-Ye Mao 1, Hui-Ting Wen1, Suthathong Homya 9, Kritana
Prueksakorn 10 *, Jun Zhao 1, 3 and
Ming-Fu Yang 3, 11
1 Yibin Vocational and Technical College, Yibin,
Sichuan, 644000, China
2 School of Chinese Medicinal Material Resources,
Guangdong Pharmaceutical University, Guangzhou, 510006, China
3 Yi Minority Culture Research Center of the Key
Research Base of Philosophy and Social Sciences of Sichuan Province
4 State Key Laboratory of Urban and Regional Ecology,
Research Center for Eco-Environmental Sciences, Chinese Academy of
Sciences, Beijing 100085, China
5 Department of Biological Science, Faculty of Applied
Sciences, Rajarata University of Sri Lanka, Mihintale, 50300, Sri Lanka
6 Environmental Education Center, Xishuangbanna
Tropical Botanical Garden, Chinese Academy of Sciences, Mengla Yunnan,
666100, China; xtbg_liujx@qq.com
7 Environment and Plant Protection Research Institute,
Chinese Academy of Tropical Agricultural Sciences,Haikou, 570100,
China; hhp18@163.com
8 Honghe Meteorological Bureau, Yunnan, 661100, China;
125529676@qq.com
9 Department of Environmental Science, Faculty of
Science and Technology, Phuket Rajabhat University, 83120, Thailand;
suthathong.h@pkru.ac.th
10 Faculty of Environment and Resource Studies,
Mahidol University, Nakhon Phathom, 73170, Thailand
11 Yanyuan Vocational Middle School of Liangshan Yi
Autonomous Prefecture, Sichuan, 615500, China
First author: yangfengchun@gdpu.edu.cn
Co-first author: chayasarathchandra@gmail.com
Correspondence: kritana.pru@mahidol.ac.th
Abstract: The Yuanjiang dry-hot valley features hot and dry
climate, low vegetation and soil degradation. It had lush vegetation in
the past, but has become degraded in recent decades. Understanding the
interrelationship between species and the habitat is necessary to
explain this change. In this study, a link between fern and fern allies
- a group that is hypersensitive to environmental factors and their
circumstances is constructed. Intensive transects and plots were
designed to be proxies for extant fern and fern allies, and their
habitats. Fifty years of meteorological records of precipitation and
temperature along altitude and river running direction (latitudinal)
were employed. Alpha and beta diversity are used to access diversity.
Species_estimated, Singletons, Uniques, ACE, ICE, and Chao2, which
associate to abundance and rarity, are subscribed to the correlation
between fern and fern allies, and their ecosystem. Eight species,Selaginella pseudopaleifera, Aleuritopteris squamosa, Adiantum
malesianum, Pteris vittata, Davallia trichomanoides, Sinephropteris
delavayi, Selaginella jugorum, and Lygodium japonicum are used
as indicators of a typical xeric and sun-drying habitat. The results
indicate (1) accompanied by dramatically shrinking habitats, fern and
fern allies are in very low diversity and abundance, whereas the rarity
is relatively high; (2) for fern and fern allies, environmental factors
are positive when altitude goes up; and (3) eight indicator species are
latitudinally correlated with fern and fern allies along the river
running direction.
Keywords: diversity; dry-hot valley; fern; indicator; rarity
1. Introduction
The dry-hot valley
is
represented by high temperature and dry air throughout the year, and it
is one of the arid ecosystems in the world influenced by climate change
(Dong et al ., 2014; Wang et al ., 2016; Srivastava et
al ., 2018).
Climate
change has resulted in extensive alteration of terrestrial ecosystems,
including the change in biogeographic distribution and biological
diversity, and the interaction between organisms and their living
circumstances (Hea et al ., 2018). Understanding the
interrelationship between plants and their environmental conditions in
arid ecosystems is a preliminary step to interpret the mechanism of
adaptation, or giving a feasible solution for saving earthbound
environment (Jina et al ., 2019).
Yuanjiang dry-hot valley is located in the upper and middle region of
Yuanjiang-Red River, an international river shared by China and Vietnam
(6. GMS Operations Center, 2017). In the valley, the nature of soil,
water and fertilizer are not in good condition (Su et al ., 2015;
Yang et al ., 2018). The vegetation has changed gradually in the
past 500 years, but has been degraded significantly in recent decades
causing a dry and hot tropical ecosystem (Xu et al ., 1985).
Broadleaf and evergreen plants have been shrinking, while it is
currently dominated by montane savannah, covered with few trees and high
grasses (Zhang et al ., 2009). To elucidate this change, it is
necessary to understand a corresponding pattern between plants and
environmental factors such as humidity, temperature and water
availability.
Fern
and fern allies are traditionally considered hypersusceptible to
environmental changes; their occurrence or disappearance is closely
correlated to their living place (Abotsi et al ., 2020). In this
study, the relationship between fern and fern allies and environments in
the Yuanjiang dry-hot valley is investigated together with species
population and environment factors.
2. Materials & Methods
2.1. Transect and plot designing
The research site is the core area of Yuanjiang dry-hot valley with a
length of 105.26 km along the river channel, oriented northwest to
southeast (Figure 1, A). Six transects were arranged randomly (Figure 1,
B) with a concept of no interference by human activities, where three
transects
were set up altitudinally along a mountain slope, and the other three
latitudinally along the riverside (Table 1). Altitudinal transects were
in height vertically, with ten plots
arranged equidistantly 20 m apart from the lower plot to the higher. The
latitudinal transects were in length along the river channel, and ten
plots were spaced at a distance of 100 m evenly (Figure 2). Plots were 2
m × 2 m squared. All fern species in the sampling sites were
investigated and nomenclature following Flora Yunnanica (Wuet al ., 2006).
Table 1. Location, altitude and circumstance, and orient of
each transect