Comparison of methane emissions among invasive and native mangrove species in Dongzhaigang, Hainan Island

Yixin He; Wei Guan; Dan Xue; Liangfeng Liu; Changhui Peng; Baowen Liao; Ji Hu; Qiu'an Zhu; Yanzhen Yang; Xu Wang; Guanyi Zhou; Zhongming Wu; Huai Chen

doi:10.1016/j.scitotenv.2019.133945

Comparison of methane emissions among invasive and native mangrove species in Dongzhaigang, Hainan Island

Sci Total Environ. 2019 Dec 20:697:133945. doi: 10.1016/j.scitotenv.2019.133945. Epub 2019 Aug 15.

Authors

Yixin He¹, Wei Guan², Dan Xue¹, Liangfeng Liu¹, Changhui Peng³, Baowen Liao², Ji Hu¹, Qiu'an Zhu⁴, Yanzhen Yang⁴, Xu Wang², Guanyi Zhou², Zhongming Wu², Huai Chen⁵

Affiliations

¹ CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China.
² Research Institute of Tropical Forestry, Chinese Academy of Forestry, Guangzhou 510520, China.
³ State Key Laboratory of Soil Erosion and Dryland Farming, College of Forestry, Northwest A&F University, Yangling 712100, China; Institute of Environment Science, Department of Biology Science, University of Quebec at Montreal (UQAM), 201 President-Kennedy, Montréal H2X 3Y7, Canada.
⁴ State Key Laboratory of Soil Erosion and Dryland Farming, College of Forestry, Northwest A&F University, Yangling 712100, China.
⁵ CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China; State Key Laboratory of Soil Erosion and Dryland Farming, College of Forestry, Northwest A&F University, Yangling 712100, China. Electronic address: chenhuai@cib.ac.cn.

PMID: 31473551
DOI: 10.1016/j.scitotenv.2019.133945

Abstract

The strength of methane (CH₄) source of mangroves is not well understood, especially when including all CH₄ pathways in consideration. This study measured CH₄ fluxes by five pathways (sediments, pneumatophores, water surface, leaves, and stems) from four typical mangrove forests, including Kandelia candel without pneumatophores and three species with pneumatophores: Sonneratia apetala, Laguncularia racemosa and Bruguiera gymnorhiza-Bruguiera sexangula. The CH₄ fluxes from sediments were 4.82±1.46mgCH₄m^-2h^-1 for K. candel and 1.36±0.17mgCH₄m^-2h^-1 for the other three with pneumatophores. Among the three communities with pneumatophores, S. apetala community had significantly greater emission rate than the other two (P<0.05). Pneumatophores in S. apetala were found to significantly decrease CH₄ emission from sediments (P<0.01), while those in B. gymnorhiza-B. sexangula were significantly increase it (P<0.05). CH₄ fluxes from waters were 3.48±1.11mgCH₄m^-2h^-1, with the highest emission rate in the K. candel community for the duck farming. Leaves of mangroves except for those of K. candel were a weak CH₄ daytime sink, but stems were a weak source. The total 72ha of mangroves in the Changning river basin emitted about 8.10Gg CH₄ per year, with a weighted emission rate of about 1.29mgCH₄m^-2h^-1. Our results suggested that mangroves are only a small methane source to atmosphere with great contribution from sediments and waters, only slight contribution from leaves and stems. Pneumatophores of different mangrove species played different roles in CH₄ fluxes from sediments.

Keywords: Biogeochemistry; Greenhouse gases; Mangrove forests; Methane budget; Tropical ecosystems.

MeSH terms

Air Pollutants / analysis*
China
Environmental Monitoring
Introduced Species*
Methane / analysis*
Rhizophoraceae
Wetlands*

Substances

Air Pollutants
Methane