Relationship between Wetland Plant Communities and Environmental Factors in the Tumen River Basin in Northeast China

Xiaojun Zheng,Weihong Zhu,Chunguang He,Chunyan Lu,Jing Fu,Noelikanto Ramamonjisoa

doi:10.3390/su11061559

Xiaojun Zheng, Weihong Zhu + Show 4 more

Open Access

https://doi.org/10.3390/su11061559

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Abstract

Understanding what controls wetland vegetation community composition is vital to conservation and biodiversity management. This study investigates the factors that affect wetland plant communities and distribution in the Tumen River Basin, Northeast China, an internationally important wetland for biodiversity conservation. We recorded floristic composition of herbaceous plants, soil properties, and microclimatic variables in 177, 1 × 1 m2 quadrats at 45 sites, located upstream (26), midstream (12), and downstream (7) of the Basin. We used TWINSPAN to define vegetation communities and canonical correspondence analysis (CCA) to examine the relationships between environmental and biological factors within the wetland plant communities. We recorded 100 plant species from 93 genera and 40 families in the upstream, 100 plant species from 57 genera and 31 families in the midstream, and 85 plant species from 76 genera and 38 families in the downstream. Higher species richness was recorded upstream of the River Basin. The plant communities and distribution were influenced by elevation, soil properties (total potassium, pH, and available phosphorus), and microclimate variables (surface temperature, precipitation, average temperature, sunshine hours, and relative humidity). More than any other factor, according to our results, elevation strongly influenced the structure of wetland plant communities. These findings support prevailing models describing the distribution of wetland plants along environmental gradients. The determination of the relationship between soil and plants is a useful way to better understand the ecosystem condition and can help manage the wetland ecosystem.

Highlights

Freshwater wetlands are one of the most productive ecosystems and are indispensable for the countless benefits or “ecosystem services” they provide, such as biodiversity support, food and building materials, flood abatement, freshwater supply, and carbon sequestration [1,2,3]
One hundred taxa were found in the upstream area, from 93 genera and 40 families, and 100 taxa were in the midstream area from 57 genera and 31 families
Upstream communities were mostly affected by elevation, precipitation, and total potassium, whereas midstream and downstream communities appear to be mostly structured by soil properties such as available potassium and available phosphorus

Summary

Introduction

Freshwater wetlands are one of the most productive ecosystems and are indispensable for the countless benefits or “ecosystem services” they provide, such as biodiversity support, food and building materials, flood abatement, freshwater supply, and carbon sequestration [1,2,3]. Information on the factors that govern community assembly rule and distribution is required [4] Such information can benefit restoration programs, in regard to choosing suitable species/communities to initiate re-vegetation [5] as well as site improvement in degraded wetlands [6,7]. One body of literature found a greater influence of soil properties such as soil moisture, salt content [11], soil organic matter [12], nitrate-N [13], and soil microbial communities [14]. Another body of research revealed that, more than soil properties, geographical attributes are more influential. The literature suggests that (i) changes in environmental variables can have important effects on species composition and establishment, though stochastic processes may be operating [18,19], and (ii) the driving factors affecting wetland plant communities could be site specific and depend on the actual plant community [20]

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