Seagrass ecosystems support high biodiversity and productivity and constitute critical links to adjacent ecosystems. However, there is a growing concern that increasing recreational navigation may affect its ecologica...Seagrass ecosystems support high biodiversity and productivity and constitute critical links to adjacent ecosystems. However, there is a growing concern that increasing recreational navigation may affect its ecological processes and functions, which may affect its recreational and tourism values, compromising local economies and livelihoods. The long-term impacts (1996-2011) of recreational navigation on seagrass benthic community structure were assessed by addressing the question of whether long-term effects of recreational navigation had a significant impact on seagrass community structure and on its benthic faunal assemblages. Findings evidenced: 1) a consistent spatio-temporal gradient in the ecological conditions of seagrasses across the scoured areas, with increased percent seagrass cover, density and canopy height, and seagrass benthic biodiversity with increasing distance from disturbed areas;2) a decline in percent seagrass cover, and an increased macroalgal and cyanobacterial percent cover through time around the disturbed areas;3) a significant shift in seagrass assemblage biodiversity as a response to boating that followed the intermediate disturbance hypothesis;4) an adverse effect on the spatial distribution and survival of multiple benthic invertebrate taxa;and 5) a significant decline in cnidarians, echinoids, ophiuroids, holothurians, and gastropods, and an increase in polychaetes, platyhelminths, and hermit crabs, particularly in areas exposed to boating. Spatio-temporal variation in seagrass community structure explained the observed variation in benthic faunal assemblages. The long-term consequences on ecosystem functions and management needs are discussed to foster the conservation of seagrasses.展开更多
Seagrass research in China is still in its infancy. Even though there has been progress recently, there is still a great deal of research needed to gain a better understanding of seagrass. In this article we review an...Seagrass research in China is still in its infancy. Even though there has been progress recently, there is still a great deal of research needed to gain a better understanding of seagrass. In this article we review and discuss the advances in seagrass research in China from two aspects: (1) seagrass species and their distribution; (2) seagrass research in China, including studies on their taxonomy, ecology, photosynthesis, applications in aquaculture, salt-tolerance mechanisms and other research topics. A total of 18 seagrass species belonging to 8 genera are distributed in nine provinces and regions in China (including Hong Kong and Taiwan), as well as the Xisha and Nansha Archipelagos. They can be divided into two groups: a North China Group and a South China Group. Based on the seagrass distribution, the Chinese mainland coast can be divided into three sections: North China Seagrass Coast, Middle China Seagrass Coast, and South China Seagrass Coast. Ecological studies include research on seagrass communities, nutrient cycling in seagrass ecosystems, genetic diversity, pollution ecology and research in the key regions of Shandong, Guangdong, Guangxi, and Hainan. Seagrass species and their locations, community structure, ecological evaluation, epiphytes, ecological functions and threats in the key regions are also summarized. Other studies have focused on remote sensing of seagrass, threatened seagrass species of China, and pollen morphology of Halophila ovalis.展开更多
Suspended particulate matter(SPM) has been known as an important variable in the organic matter flow of coastal ecosystem. Half of burial carbon in seagrass meadows is contributed by allochthonous sources that compose...Suspended particulate matter(SPM) has been known as an important variable in the organic matter flow of coastal ecosystem. Half of burial carbon in seagrass meadows is contributed by allochthonous sources that compose the SPM such as phytoplankton, seagrass detritus, marine snow aggregates and terrestrially derived particles. Each composition of the SPM contributes different roles and is important to be identified, for instance,the exact contribution of seagrass detritus will be useful for determination of carbon export through the detritus form in seagrass meadows. Here, the SPM of seagrass meadows is studied in Bintan Island and the Selayar Archipelago. The aim of this research is to determine the source origin of the SPM using a stable isotope signature.In order to fulfill this aim, the objectives are defined as:(1) to specify the stable isotope signature(δ13C and δ15N)of the SPM, and(2) to determine the proportional distribution of the SPM's prospectus sources. The result shows that the possibility of the source origin of the SPM includes a seagrass fraction(Enhalus acoroides and Thalassia hemprichii), terrestrial C4 plant, macroalgae, and terrestrial C3 plant. The SPM lies between the marine-and terrigenous-end members. However, it seems that the SPM is more to be terrigenous-end and allochthonous.According to a Bayesian mixing model, the terrestrial C4 has the highest contribution of the SPM at all sites except Barugaia and Pasi Island in Selayar(i.e., the highest contribution of the SPM is from the detritus of E. acoroides).The second contribution has been contributed by either seagrass detritus(E. acoroides or Th. hemprichii) or terrestrial C3 plant. The finding of this study indicates that there is a strong influence of the terrigenous sources in the SPM of the seagrass meadows.展开更多
文摘Seagrass ecosystems support high biodiversity and productivity and constitute critical links to adjacent ecosystems. However, there is a growing concern that increasing recreational navigation may affect its ecological processes and functions, which may affect its recreational and tourism values, compromising local economies and livelihoods. The long-term impacts (1996-2011) of recreational navigation on seagrass benthic community structure were assessed by addressing the question of whether long-term effects of recreational navigation had a significant impact on seagrass community structure and on its benthic faunal assemblages. Findings evidenced: 1) a consistent spatio-temporal gradient in the ecological conditions of seagrasses across the scoured areas, with increased percent seagrass cover, density and canopy height, and seagrass benthic biodiversity with increasing distance from disturbed areas;2) a decline in percent seagrass cover, and an increased macroalgal and cyanobacterial percent cover through time around the disturbed areas;3) a significant shift in seagrass assemblage biodiversity as a response to boating that followed the intermediate disturbance hypothesis;4) an adverse effect on the spatial distribution and survival of multiple benthic invertebrate taxa;and 5) a significant decline in cnidarians, echinoids, ophiuroids, holothurians, and gastropods, and an increase in polychaetes, platyhelminths, and hermit crabs, particularly in areas exposed to boating. Spatio-temporal variation in seagrass community structure explained the observed variation in benthic faunal assemblages. The long-term consequences on ecosystem functions and management needs are discussed to foster the conservation of seagrasses.
基金Supported by Guangxi Science Foundation (No. 0832030)Scientific Research Fund of Guangxi University (2008)+1 种基金UNDP/GEF/SCCBD Project (SCCBD/CPR/02/31)Guangxi Key Lab Fund (No. 07109007)
文摘Seagrass research in China is still in its infancy. Even though there has been progress recently, there is still a great deal of research needed to gain a better understanding of seagrass. In this article we review and discuss the advances in seagrass research in China from two aspects: (1) seagrass species and their distribution; (2) seagrass research in China, including studies on their taxonomy, ecology, photosynthesis, applications in aquaculture, salt-tolerance mechanisms and other research topics. A total of 18 seagrass species belonging to 8 genera are distributed in nine provinces and regions in China (including Hong Kong and Taiwan), as well as the Xisha and Nansha Archipelagos. They can be divided into two groups: a North China Group and a South China Group. Based on the seagrass distribution, the Chinese mainland coast can be divided into three sections: North China Seagrass Coast, Middle China Seagrass Coast, and South China Seagrass Coast. Ecological studies include research on seagrass communities, nutrient cycling in seagrass ecosystems, genetic diversity, pollution ecology and research in the key regions of Shandong, Guangdong, Guangxi, and Hainan. Seagrass species and their locations, community structure, ecological evaluation, epiphytes, ecological functions and threats in the key regions are also summarized. Other studies have focused on remote sensing of seagrass, threatened seagrass species of China, and pollen morphology of Halophila ovalis.
基金The Core Competence Research Project 2014the Research Agenda COREMAP-CTI 2015-2016the "Unggulan LIPI" Research Project 2017
文摘Suspended particulate matter(SPM) has been known as an important variable in the organic matter flow of coastal ecosystem. Half of burial carbon in seagrass meadows is contributed by allochthonous sources that compose the SPM such as phytoplankton, seagrass detritus, marine snow aggregates and terrestrially derived particles. Each composition of the SPM contributes different roles and is important to be identified, for instance,the exact contribution of seagrass detritus will be useful for determination of carbon export through the detritus form in seagrass meadows. Here, the SPM of seagrass meadows is studied in Bintan Island and the Selayar Archipelago. The aim of this research is to determine the source origin of the SPM using a stable isotope signature.In order to fulfill this aim, the objectives are defined as:(1) to specify the stable isotope signature(δ13C and δ15N)of the SPM, and(2) to determine the proportional distribution of the SPM's prospectus sources. The result shows that the possibility of the source origin of the SPM includes a seagrass fraction(Enhalus acoroides and Thalassia hemprichii), terrestrial C4 plant, macroalgae, and terrestrial C3 plant. The SPM lies between the marine-and terrigenous-end members. However, it seems that the SPM is more to be terrigenous-end and allochthonous.According to a Bayesian mixing model, the terrestrial C4 has the highest contribution of the SPM at all sites except Barugaia and Pasi Island in Selayar(i.e., the highest contribution of the SPM is from the detritus of E. acoroides).The second contribution has been contributed by either seagrass detritus(E. acoroides or Th. hemprichii) or terrestrial C3 plant. The finding of this study indicates that there is a strong influence of the terrigenous sources in the SPM of the seagrass meadows.
