Macroinvertebrate functional feeding groups and its relationship with
environmental factors in the Jingui River of Shenzhen
Chen Suna, Lixian Xiaa, Min
Zhangb, Qianyun Hea, Naiqi
Yua, Hongyong Xianga, Haijun
Yanga, *
a School of Ecology and Environmental Science,
Yunnan University, Kunming 650091, China
b Shenzhen Guanghuiyuan Environmental Water Co.
Ltd., Shenzhen 518000, China
Abstract:The differences in the functional diversity and species diversity of
macroinvertebrates can be based to evaluate the changes in local
environment. However, there are little available analysis on the effect
mechanism of seasons on the functional characteristics of
macroinvertebrate communities in the subtropical region. This work
compared the functional feeding groups (FFG) of macroinvertebrates in
wet season, normal season, and dry season of 2021 in Jingui River in
Shenzhen. This work mainly was aimed to comprehend the connection
between the environmental driving elements in the Jingui River and the
seasonal distribution of the FFG of macroinvertebrates. The highest
species diversity and abundance were found among the collector-gatherers
(GC), while the largest biomass was observed among the predators.
Overall, the functional diversity of the Jingui River exhibited a
significantly seasonal change. In particular, the functional diversity
decreased in wet season, implying a stronger disturbance. A multiple
regression analysis revealed that the species diversity and stream
environmental parameters might account for 12.8% - 72.9% of the
functional diversity of macroinvertebrates.
Keywords: Macroinvertebrate; Functional feeding groups; River
ecosystem; Functional diversity
Introduction
The
group of macroinvertebrates having the same ecological purpose is called
the functional feeding groups (FFG) of macroinvertebrates (Liu et al.,
2014). Traditional research on macroinvertebrates focuses more on
community structure analysis and *Correspondence:
Corresponding Author: yanghaijun@ynu.edu.cn
species diversity instead of FFG and diversity(Brown et al., 2018).
Applying FFG in the research on structure of the macroinvertebrate
community helps to evaluate the ecosystem structure and function
completely and to simplify the complicated internal relations(Mouton et
al., 2020). In this case, differences in FFG of macroinvertebrates can
be based to evaluate the mechanism of changes in the local
environment(Zhong
et al., 2020).
Functional diversity has recently received extensive attention to
predict the connections among various ecological processes(Wang et al.,
2019). The functional diversity is formed by fundamental variation among
the interspecific functional features in clusters and the way those
traits react to environmental stresses and interference(Baker et al.,
2021). Evaluating the aquatic ecosystems is of high significance due to
the variety of its forms and habits, which may respond to the
environmental pressures in multiple ways(Ochieng et al., 2019). For
examples, Talley used functional categories to examine the connection
between macroinvertebrate habitats and communities in California Bay
tidal flats(Talley et al., 2000), and Thrush investigated how
macroinvertebrates contribute to the intertidal ecology(Thrush et al.,
2006). The functional diversity is depended by the ability of biological
communities to predict the rapidity and dependability of environmental
processes(Mason et al., 2005). As a combination of many environmental
factors, riverbed structure influences the community structure and
functional diversity of macroinvertebrates directly or indirectly(Zhu et
al., 2020). Meanwhile, the functional diversity displays greatly
different functional features and can indicate how those traits react to
environmental interference(Zhong et al., 2020). FFG and functional
diversity indices demonstrate the responses to environmental stressors
and reflect the changes in community organization(Li et al., 2022). In
addition, functional diversity is generally handled by unique categories
in the river benthic ecosystems(Wang et al., 2019). The environmental
status depends on the biological traits that show how to respond to
pressure from the external environment(Lavorel et al., 1997). Mason
believed that the functional variety can’t be effectively represented by
a single index(Mason et al., 2005). Electing correct indexes is the
essential for creating a functional diversity biological assessment
system(Jiang et al., 2021). Villeger presented three multidimensional
indices of consecutive function features to investigate the three
distinct aspects of the functional diversity(Villeger et al., 2008).
Currently, the river benthic habitats are rarely mentioned, and the
functional diversity indices are primarily selected to investigate the
terrestrial plant ecosystems(Chen et al., 2018; Liu et al., 2019).
The Jingui River is the secondary tributary of the Pingshan River, which
is included in the Dongjiang River system. The Jingui River Basin
accounts for roughly 50% of the area of the Chi’ao Reservoir and is the
primary source of the reservoir. The ecological environment of the
Jingui River has been somewhat put in danger by year-round sediment
deposition, mountain torrents, and haphazard human activity. The
Shenzhen Municipal Bureau of Planning and Natural Resources, therefore,
started a comprehensive renovation for the limited watershed of the
Jingui River in September 2020, which primarily consisted of flood
control and ecological restoration. This work evaluated the biological
characteristics and FFGs of the macroinvertebrates in the Jingui River,
and analyzed the connection between species diversity and functional
diversity. Results in this work may offer some useful information for
assessing the community structure and ecosystem stability of the
macroinvertebrates.
Materials and methods
Study area and macroinvertebrate sampling
The Jingui River was situated in the Pingshan New District of Shenzhen,
Guangdong Province, China (Fig. 1). The Pingshan River Basin is affected
by a subtropical marine monsoon climate, and the average annual
temperature and precipitation are 22°C and 1,984 mm, respectively. The
river originates on the southern slope of Tianxin Mountain and flows
from southeast to northwest before accessing the Chi’ao Reservoir.
Macroinvertebrates in the Jingui River were sampled in July (wet
season), October (normal season), and December (dry season) in 2021
using a Surber sampler (30 × 30 cm, 500 μm mesh) from three quantitative
replicates. The samples covered the most representative
macroinvertebrate microhabitats of each site. The sampled
macroinvertebrates were preserved in 75% ethanol and then recognized
and categorized in the laboratory with a stereo microscope (Olympus
SZX7). The FFGs were employed to further classify the macroinvertebrates
into shredder (SH), collector-filterer (FC), collector-gatherer (GC),
scraper (SC) and predator (PR)(Lin et al., 2022).