A geomorphic approach to global classification for natural inland wetlands and rationalization of the system used by the Ramsar Convention – a discussion

Globally, the most widely used wetland classification is that adopted by the contracting parties of the Ramsar Convention, which is the Convention on Wetlands of International Importance especially as Waterfowl Habitat. A review of the Inland Wetland component of this system shows that mixed criteria are used to separate the wetlands, and that not all natural inland wetlands have been addressed. A classification system using landform and hydro-period, which results in 13 primary geomorphically non-emergent types for natural wetlands, is proposed to describe the full variety of wetlands at a primary level around the globe, and is suggested to be incorporated as the first-tier of the Ramsar classification.The proposed classification has been designed so wetlands can be described, classified and compared systematically. This paper attempts to reconcile the Ramsar Classification system with the proposed approach. The intention in this paper is not to displace the Ramsar Classification, but rather to indicate its inherent underlying geomorphic structure, and hence re-order its hierarchical framework. This adjustment to the existing classification system would highlight underlying similarities between wetlands so that global comparisons can be more readily made. It also has considerable advantages for a staged, systematic discrimination and classification of the vast array of differing wetlands globally.The use of geomorphic and hydrologic elements as the primary and secondary divisions with the more commonly used Ramsar Classification terms as a tertiary division, provides a logical structure to compare and contrast wetlands globally.     

Conservation and management issues of Prespa National Park

The present article describes the human activities inthe area and their changes and trends, given that thecontemporary nature conservation key issues areclosely related to past and present socio-economic andcultural conditions, both within Prespa itself andoutside of it. The liberation of Prespa, a remote andrather socially isolated borderline area, from Ottoman occupation took place in 1912–13. Recentevents in its environmental history have been forestclearings and human depopulation in the Civil War(1944–49), irrigation system construction in the1960s, its discovery by ornithologists in the late1960s, the high emigration rates of 1960–1980, itsdesignation as a National Park in 1974, thedestructive development works of 1984–86 afterGreeces entry to the EEC and the conversion to intensivebean cultivation in the mid 1980s.The human population of ca 7000 at the start of thiscentury suffered an almost 80% decrease after theCivil War. A resettlement in the mid 1950s increasedthe population by 40% but in the 1970s emigrationreduced it to its previous size of around 1500, stillits present size. The extensive and diverse farmingsystems of previous centuries changed gradually afterthe construction of an irrigation network in the1960s, which twenty years later and along withinternational changes in production and economypatterns, made possible the present day domination ofa bean monoculture within irrigated croplands. Thiswas accompanied by increased energy inputs,mechanisation and the use of chemicals.Intensification of agriculture brought increasedincomes which attracted also livestock keepers,resulting in a 56% decrease in numbers of livestockin 1964–1993. Cattle are presently kept for meatproduction only. They graze on the mountains, and nolonger in the meadows around the lakeshore. A localshorthorn breed accounting for 93% of all cattle in1963 declined to less than 18% in 1993. Fishing aimedmainly at carp and Prespa bleak, continues today as inthe past to be a source of supplementary income.Eighty-six per cent of the – mainly oak and beech –forests are State owned and the rest belong to localmunicipalities. The forest area has not changedessentially in the last 40 years, but forest roadshave expanded. Forests provide mainly fuelwood forlocal needs and small quantities of industrial timber.No specific management is conducted to safeguard theconservation values of the forest, the majority ofwhich consists of even aged coppiced stands withlimited value for wildlife. Manufacturing never playedan important role for the economy of the area. Tourismhas increased in the last 20 years, concentratedmainly in summer and spring. Accommodation in thevillages is not yet satisfactory though it hasimproved enormously in recent years. The NationalParks infrastructure for visitors remains poor.Tourist pressure generally is not yet that high toimpact drastically the social and environmentalfabric. In places, hunting, angling and poaching cannegatively affect the target species. The constructionof the irrigation network in the eastern part of LakeMikri Prespa was the most important change to thelandscape and the habitats of Prespa the last 30years. It resulted in the embankment of free-flowingstreams, drainage of wet meadows and dramaticreduction of trees and hedges. In the last 15 years,the reedbeds, no longer burnt or mowed and assisted byincreased nutrient loadings from agricultural runoff,have expanded landward to occupy formerly open,periodically flooded, areas. The above changes inhabitats and land use have brought an impoverishmentof biodiversity which can be seen in the exterminationor the decrease in the numbers of certain plant andbird species.The problems preventing a better management of theNational Park and the perpetuation of its values areinappropriate legislation, the poor degree ofcoordination of the public services, the lack of botha specific National Park Service in Greece and amanagement authority for the Park and the hostileattitude of local people due to their limitedinformation and involvement. The scenic beauty, thewetlands and a number of rare habitats, the diversityof habitats, flora and fauna, the endemic life forms,the rare mammals and the colonial waterbirds, thelocal architecture and the cultural expressions suchas the Byzantine monuments, are the values of Prespathat must be preserved as a whole. The initialconservation efforts aimed at preserving biodiversitybut later it became apparent that not only are humansan inseparable part of the whole, but additionally,several of their extensive activities have contributedsubstantially to the rich biodiversity of the area.Through the prerequisites of keeping a balance betweenprimary and tertiary sector activities and ofrevitalizing the social fabric, the following are thekey management and conservation issues of today: anunequivocal agreement on the values to be preservedand their limits; the formation of a managementauthority; a new realistic protection and land usezoning; the diversification and extensification of allfarming activities; the restoration of the wet meadowhabitats; the ensuring of a high water level and agood water quality for both lakes through tri-lateralcooperation between Greece, Albania and FYROM; and theestablishment of a permanent environmental monitoringscheme.     

A review of the salt sensitivity of the Australian freshwater biota

In Victoria, Australia, both dryland salinity and salinity in irrigation regions are serious agricultural problems. One option to control the latter is to pump groundwater to maintain it below the surface. However, this leaves a saline wastewater for disposal, probably into local streams or wetlands. This review of the salt sensitivity of the biota of Australian streams and wetlands gives information of interest to those responsible for developing controls on these discharges. The review addresses the lethal and sub-lethal effects of salinity on microbes (mainly bacteria), macrophytes and micro-algae, riparian vegetation, invertebrates, fish, amphibians, reptiles, mammals, and birds. Data suggest that direct adverse biological effects are likely to occur in Australian river, stream and wetland ecosystems if salinity is increased to around 1 000 mg L⁻¹. The review highlights a general lack of data on the sensitivity of freshwater plants and animals to salinity increases.     

Insect diversity in Gonggeom‐ji,the first protected paddy field wetland in Korea

Gonggeom‐ji pond is the first protected paddy field wetland area, designated by the Ministry of Environment of Korea in 2011, because of its high biodiversity and historic value. It contains reservoirs, paddy fields, and a forest site that provides diverse niches for insects. Quantitative methods were used in this study to estimate the insect diversity of this region. A transect of 50 m was designated in each site (reservoirs, paddy fields, and a forest site). Data were collected using sweeping and pitfall traps along each transect in May, August, and November 2017, representative of the seasons—spring, summer, and autumn, respectively. As a result, a total of 1079 individual insects representing 170 species from 60 families within nine orders were collected. Diversity, richness, and evenness indices were the highest in the forest site in May (4.77, 8.6, and 0.91, respectively). The dominance index was the highest in the forest site in November (0.64). Similarity index was the highest in the reservoir in May and August (0.519). These results would help compare different sites and their vegetation to assess relationships between insects and habitats.     

Methane emissions reduce the radiative cooling effect of a subtropical estuarine mangrove wetland by half

The role of coastal mangrove wetlands in sequestering atmospheric carbon dioxide (CO₂) and mitigating climate change has received increasing attention in recent years. While recent studies have shown that methane (CH₄) emissions can potentially offset the carbon burial rates in low‐salinity coastal wetlands, there is hitherto a paucity of direct and year‐round measurements of ecosystem‐scale CH₄ flux (F_CH4) from mangrove ecosystems. In this study, we examined the temporal variations and biophysical drivers of ecosystem‐scale F_CH4 in a subtropical estuarine mangrove wetland based on 3 years of eddy covariance measurements. Our results showed that daily mangrove F_CH4 reached a peak of over 0.1 g CH₄‐C m^?2 day^?1 during the summertime owing to a combination of high temperature and low salinity, while the wintertime F_CH4 was negligible. In this mangrove, the mean annual CH₄ emission was 11.7 ± 0.4 g CH₄‐C m^–2 year^?1 while the annual net ecosystem CO₂ exchange ranged between ?891 and ?690 g CO₂‐C m^?2 year^?1, indicating a net cooling effect on climate over decadal to centurial timescales. Meanwhile, we showed that mangrove F_CH4 could offset the negative radiative forcing caused by CO₂ uptake by 52% and 24% over a time horizon of 20 and 100 years, respectively, based on the corresponding sustained‐flux global warming potentials. Moreover, we found that 87% and 69% of the total variance of daily F_CH4 could be explained by the random forest machine learning algorithm and traditional linear regression model, respectively, with soil temperature and salinity being the most dominant controls. This study was the first of its kind to characterize ecosystem‐scale F_CH4 in a mangrove wetland with long‐term eddy covariance measurements. Our findings implied that future environmental changes such as climate warming and increasing river discharge might increase CH₄ emissions and hence reduce the net radiative cooling effect of estuarine mangrove forests.     

广州市湿地公园植物调查与分析

为更好地提高湿地公园的生态服务能力、加强湿地公园的物种保育功能并促进湿地公园建设和发展质量,对广州地区20个湿地公园植物进行了实地调查。结果表明,调查区域共有205种湿地植物;对其物种组成、生活型、生态习性、优势科属及应用频度等的分析表明,湿地公园的植物群落结构比较简单,主要植物种类同质化现象很严重,保护和珍稀植物种类应用较少等。基于此,推荐了55种本土植物作为广州市湿地公园进行生态改造和景观配置的候选物种,同时还提出了对未来湿地公园的建设和管理的若干建议。     

Length–weight relationships of four fish species from Vembanad-Kole Wetland (Kerala,India)

The length–weight relationships (LWRs) of four fish species were determined from Vembanad-Kole Wetland, Kerala, India between June 2015 and May 2016. Fish samples were collected monthly from various fishing gears such as gill nets (50 m long and 1.5 m height, mesh sizes 30–100 mm, soaking time 8 hr) and seine nets (mesh sizes 8–16 mm). Values of the parameter b ranged from 2.896 to 3.165 and such values are within the expected range. This study reports the new maximum total length for Channa pseudomarulius and Hyporhamphus xanthopterus.