World's Wetlands Research Articles

29 years of carbon sequestration in two constructed riverine wetlands

The International Panel on Climate Change (IPCC) has made it clear that a reduction in carbon emissions and a promotion in carbon sequestration are necessary in order to prevent the planet from reaching catastrophic warming levels of 1.5 °C globally. The IPCC identifies the investment in “high‑carbon ecosystems” as a potential mitigation strategy, with one such ecosystem being wetlands. Historically, the majority of the world's wetlands have been destroyed due to human activities, with the midwestern U.S. being one of the most affected regions. Only in recent history has the U.S. sought to remedy this by mandating the construction of wetlands to replace those that are drained. While long-term carbon sequestration rates for natural wetlands are well-documented, it is unknown how constructed wetlands sequester carbon long-term. The Olentangy River Wetland Research Park (ORWRP) in Columbus, Ohio, USA is an ideal location to research this due to its extensive datasets collected over 29 years of biogeochemical and ecological monitoring. We used soil core samples taken across two constructed freshwater wetlands to quantify carbon storages and paired this data with similar studies at 18-month, 10-year, and 15-year milestones to create a timeline of carbon sequestration across 29 years. Our findings suggest that both wetlands have sequestered relatively equal amounts of carbon since construction and neither have shown a net gain or loss since year 15. At year 29, the average carbon storage between both wetlands is 3.58 ± 2.21 kg C m−2 which equates to 0.12 ± 0.08 kg C m−2 yr−1, which is similar to other constructed wetlands. Results indicate that these wetlands likely have reached stability and are not expected to exhibit future carbon gains or losses under current conditions. Because these and other constructed wetlands have greater carbon sequestration rates than other options for conversion of croplands, they represent a successful climate change mitigation strategy.

Nutrient Use Efficiency and Cucumber Productivity as a Function of the Nitrogen Fertilization Rate and the Wood Fiber Content in Growing Media.

A peat substrate is made from peat from drained peatlands, which is a limited resource. A realistic estimate is that 50% of the world's wetlands have been lost. Peat is used in horticulture, especially for the cultivation of vegetables in greenhouses. The consequences of peatland exploitation are an increase in the greenhouse effect and a decrease in carbon stocks. Wood fiber can be used as an alternative to peat. The chemical properties of growing media interact and change continuously due to the small volume of growing media, which is limited by the growing container. This study aims to gain new knowledge on the impact of nutrient changes in the microbial degradation of carbon compounds in wood fiber and mixtures with a peat substrate on the content and uptake of nutrients required by plants. The cucumber (Cucumis sativus L.) variety 'Dirigent H' developed in the Netherlands was cultivated in growing media of a peat substrate and wood fiber: (1) peat substrate (PS); (2) wood fiber (WF); (3) wood fiber and peat substrate 50/50 v/v (WF/PS 50/50); (4) wood fiber and peat substrate 25/75 v/v (WF/PS 25/75). The rates of fertilization were the following: (1) conventional fertilization (CF); (2) 13 g N per plant (N13); (3) 23 g N per plant (N23); (4) 30 g N per plant (N30). The experiment was carried out with three replications. As the amount of wood fiber increased, the humidity and pH of the growing media increased. The fertilization of the cucumbers with different quantities of nitrogen influenced the nutrient uptake. The plants grown in the 50/50 and 25/75 growing media had the best Cu uptake when fertilized with N23. When the plants grown in the wood fiber media and the 50/50 media were fertilized with N13, N23, and N30, the Mn content in the growing media at the end of the growing season was significantly lower than the Mn content in the media with conventional fertilization. Thus, nitrogen improved the uptake of Mn by the plants grown not only in the wood fiber, but also in the combinations with a peat substrate. Growing plants in wood fiber and fertilizing them with N13 can result in the optimum uptake of micronutrients. The number and biomass of cucumber fruits per plant were influenced by the amount of wood fiber in the growing media and the application of nitrogen fertilizer. The highest number of fruits and biomass of fruits per plant obtained were significantly higher when the cucumbers were grown in WF/PS 50/50 growing media with additional N13 fertilization.

Hydroclimatic Vulnerability of Wetlands to Upwind Land Use Changes

AbstractDespite their importance, wetland ecosystems protected by the Ramsar Convention are under pressure from climate change and human activities. These drivers are altering water availability in these wetlands, changing water levels or surface water extent, in some cases, beyond historical variability. Attribution of the effects of human and climate activities is usually focused on changes within the wetlands or their upstream surface and groundwater inputs. However, the reliance of wetland water availability on upwind atmospheric moisture supply is less understood. Here, we assess the vulnerability of 40 Ramsar wetlands to precipitation changes caused by land use and hydroclimatic change occurring in their upwind moisture‐supplying regions. We use moisture flows from a Lagrangian tracking model, atmospheric reanalysis data, and historical land use change (LUC) data to assess and quantify these changes. Our analyses show that historical LUC has decreased precipitation and terrestrial moisture recycling in most wetland hydrological basins, decreasing surface water availability (precipitation minus evaporation). The most substantial effects on wetland water availability occurred in the tropic subtropical regions of Central Europe and Asia. Overall, we found wetlands in Central Asia and South America to be the most vulnerable by a combination of LUC‐driven effects on runoff, high terrestrial precipitation recycling, and recent decreases in surface water availability. This study stresses the need to incorporate upwind effects of land use changes in the restoration, management, and conservation of the world's wetlands.

Long-term quantification of pre and post-monsoon surface water area of Bangladesh

Since the 1990s, about 70 percent of the world's wetland ecosystem have been lost, despite the acknowledged contribution of surface waters to human well-being. Surface water is a prerequisite for agriculture, fisheries, and other human activities. It also significantly impacts the groundwater reserve, soil conditions, the environment, and the surrounding area's ecology. Bangladesh's population and economic expansion have increased the need for water resources. Therefore, monitoring the spatial and temporal distribution of surface water resources is essential. The present study used more than 2700 Landsat scenes from 1990 to 2020 to quantify the total surface water area utilizing the strength of cloud computing in the Google Earth Engine platform. Mann-Kendall trend analysis was performed to understand the trend of the surface water area. In 1990 the total pre-monsoon and post-monsoon surface water areas were 7994.91 km2 and 11453.43 km2 which is 5.38% and 7.71% of the total countries area, respectively. In 2010 and 2020, the water area was 10748.61 km2 (7.24%) and 10313.49 km2 (6.94%), respectively, in the pre-monsoon; and 10794.05 km2 (7.27%) and 15570.36 km2 (10.48%) respectively in the post-monsoon season. The overall change between 2020 and 1990 is 7994.91 km2 (1.89%) in the pre-monsoon season and 4116.93 (2.77%) in the post-monsoon season. The maximum average surface water area in the post-monsoon season was found in Sylhet (22.68%), followed by Khulna (14.52%). Rangpur was found to have the least average surface water area in both seasons (2.85% and 3.57%). Coastal regions showed a significant increasing trend in the surface water area in the pre-monsoon and post-monsoon seasons. These findings have significant implications for sustainable surface water management decisions, priority interventions, legal frameworks, and public policies to conserve valuable surface water resources in Bangladesh.

Mapping and assessment wetland ecological risk: A case on a peri-urban wetland of lower Gangatic plain, Eastern India

Wetland ecosystems (WE) are considered the most valuable natural resources and highly productive ecosystems. However, 50% of the world's wetland disappeared due to urbanization and human disturbance in the last few years. This study aims to examine the wetland ecological risk (WER) modelling of a peri-urban wetland (Chatra wetland) in English Bazar Urban Agglomeration (EBUA) located in Eastern India using subjective (knowledge-based raster mapping or KBRM model) and objective (pressure-state-response or PSR model) approaches. A Multi-co-linearity test was performed to find out the association among the parameters. WER spatial clustering was assessed using spatial autocorrelation analysis. The Friedman Wilcoxon rank test was performed to determine the significant difference between the models. The receiver operating characteristics (ROC) was used to validate the models. From both the models, it was found that eastern and southern parts of the wetland were under high to very high-risk areas compared to central and western parts of the wetland. About 70% of the total wetland was under high to very high-risk areas. The cluster maps showed that eastern and southern parts of the wetland were high-high clustered of WER, and the north-west and central parts of the wetland were characterized by low-low clustered WER. Thus, the proposed models are capable of implementing spatial management of WE and ecological sustainability.

Indicator system construction and health assessment of wetland ecosystem——Taking Hongze Lake Wetland, China as an example

Abstract Wetland is one of the most productive ecosystems in the world, a unique habitat for creatures. However, nearly half of the world's wetlands have deteriorated and disappeared in the past 100 years due to human disturbance, and the wetlands are still in a situation of continuous degradation. Current wetland evaluation cannot reveal spatial heterogeneity and its changes within the wetland. Therefore, based on remote sensing technology and landscape index, this study constructed a wetland health indicator system consisting of 12 indicators and used analytic hierarchy process (AHP) to calculate their weights. Using remote sensing data, experimental data and auxiliary data, this indicator system was applied to the Hongze Lake wetland in Jiangsu Province, China and the spatial pattern of health status was mapped. The health index of the edge of Hongze Lake is relatively lower, and the interior is healthier. The whole health index is 5.63. This study indicated that the wetland health assessment methodology proposed can effectively evaluate the spatial pattern of wetland ecosystem health and provide technical support for the protection and restoration of wetlands.

After Wetlands

Since 1900, 64 percent of the world's wetlands have disappeared. But in western literature, wetlands have been dead and dying for much longer. In our lived present, "after wetlands" is at once a material fact (since we can measure wetlands loss and count its costs) and an as-yet-unrealized fantasy spun through centuries of writing about wetlands. Attentive to this double vision, this essay performs its own temporal juxtapositions of early modern and more recent writing. Plying an "unfast" approach informed by the temporal and material indeterminacy of wetlands themselves, I offer readings of Aldo Leopold's "Marshland Elegy" (1949) and two landmark texts in the history of drainage in England: Walter Blith's The English Improver, Improved (1652) and the anonymous History or Narrative of the Great Levell of the Fenns (1685). I argue that both the promotion of early drainage schemes and latter-day lamentations of wetlands loss are tightly bound up with notions of historical time. Yet for all their focus on a future "after wetlands," the conceptual margins and drifts of these texts reveal how the ever-transforming past and present seep into the imagined future. Such temporal juxtapositions defy attempts to bring wetlands' amphibious untimeliness into the calendrical regimes of settled agriculture and the historical purview of the law. I conclude by discussing some contemporary examples of wetlands resurgence—examples that not only expose the failures of enterprising human agents to secure control over the nonhuman but also offer models for embracing those failures.

Trends in the ecological character of the world's wetlands

We assessed trends in the ecological character of wetlands generally and of Ramsar Sites reported in 2011, 2014 and 2017 by the Contracting Parties to the Ramsar Convention on Wetlands in their national reports. There was more widespread deterioration than improvement in the ecological character of wetlands generally, with deterioration increasingly more widespread between 2011 and 2017. The ecological-character trends in Ramsar Sites were significantly better than those of wetlands generally, but an increasingly more widespread deterioration of ecological character was reported between 2011 and 2017. Trends in the ecological character of wetlands generally, and of Ramsar Sites were worst in Africa and Latin America and the Caribbean, and recently also in Oceania, and better in North America and Europe. Deterioration in the ecological character of Ramsar Site was more widespread in countries with a large average area of their Ramsar Sites. This information on trends of wetland ecological character can contribute to assessing the achievement of the 2030 Sustainable Development Goal Target 6.6 and Aichi Biodiversity Target 5. Our analysis indicated that the 1971 aim of the Ramsar Convention to stem the degradation of wetlands has not yet been achieved.

Delimitación y descripción biofísica de dos turberas y de una laguna endorreica en el sector Salsipuedes-Cerro Asunción, Parque Nacional Tapantí - Macizo de la Muerte, Costa Rica

El reconocimiento de las turberas como parte esencial de los recursos humedales del mundo ha aumentado en los últimos años. Aproximadamente la mitad de los humedales del mundo son turberas y son particularmente vulnerables a las actividades humanas y el cambio climático. Presentamos la primera descripción biofísica de la vegetación, el micro relieve y el agua de turberas en el Parque Nacional del Macizo de la Muerte, Costa Rica. Tres transectos y las imágenes de LANDSAT 8 indican que las turberas difieren en las tendencias de la capa freática y la vegetación. Una turbera tenía una zona central inundada dominada por Sphagnum spp.; un sector de transición con Puya dasylirioides, Blechnum buchtienii y Chusquea subtessellata; y una capa de arbustos dominada por Pernettya prostrata y Vaccinium consanguineum. La mayoría de los árboles eran Quercus seemanni y Drymis granadensis. Otra turbera se caracterizó por Puya dasylirioides, Blechnum buchtienii y las hierbas acuáticas Paepalanthus costaricensis e Hypericum strictum, incluidos los árboles Quercus seemannii y Drymis granadensis (en los bordes del humedal). La reducción progresiva del agua en los humedales representa un riesgo de degradación y transformación de las turberas en otro tipo de ecosistema

Carbon and nutrient fluxes from floodplains and reservoirs in the Zambezi basin

Inland waters are under increasing anthropogenic stresses. In the last century, roughly two thirds of the world's wetland area disappeared, and so many dams have been constructed that currently 50% of river water passes through reservoirs before reaching the ocean. Large river systems in tropical and subtropical areas often develop extensive floodplain areas that will suffer from modifications in the flow regime as another boom in dam construction is under way. In the Zambezi catchment, we developed a comparative analysis of the biogeochemical effects of floodplains (Barotse Plains) and reservoirs (Lake Kariba) on tropical river biogeochemistry, to provide a basis to assess the net effect of eliminating wetland areas and transforming rivers into artificial lakes. To support such analyses, we propose a combination of specific sampling campaigns with sensor deployments to capture the seasonality of fluxes over large regional scales in remote areas.Dams and reservoirs alter the riverine biogeochemistry in distinct, and often different ways. While the Barotse Plains floodplain releases particles during a flood cycle, this suspended material is effectively trapped in Kariba reservoir. Seasonal production of biomass on the floodplain binds nutrients in the form of organic matter that sustains biological productivity in downstream ecosystems. Degradation of the biomass can lead to significant greenhouse gas emissions from the floodplain. The reservoir traps particles and nutrients, but carbon burial (120·103tCperyear) is offset by annual emissions of methane to the atmosphere with about 3000·103t C-CO2-equivalents. Therefore, building new dams will add permanent sinks of particles and nutrients to the land-ocean aquatic continuum, while draining riparian wetlands will disrupt their functions as temporal storage systems and source of terrestrial biomass for aquatic food chains.

Creating a safe operating space for wetlands in a changing climate

Many of the world's wetlands may be profoundly affected by climate change over the coming decades. Although wetland managers may have little control over the causes of climate change, they can help to counteract its effects through local measures. This is because direct anthropogenic impacts, such as water extraction and nutrient loading, work in concert with climate change to damage wetlands. Control of these local stressors may therefore ameliorate undesired effects of climate change, such as a shift towards dominance by invasive floating plants, increasingly frequent cyanobacteria blooms, or extinction of key species. Using the iconic Doñana wetlands in Spain as a case study, we illustrate how the concept of creating a “safe operating space” may be implemented to better ensure that ecosystems do not surpass thresholds for collapse during an era of global change.

Wetlands: conservation's poor cousins

Abstract About 5–10% of the world's land surface is currently wetland but possibly >70% is already destroyed or impaired. Conservation of these unique ecosystems lags progress in other realms, reflected in high rates of biodiversity loss. Wetlands provide a range of critically important ecosystem services including fresh water, nutrient cycling, food and fibre production, carbon fixation and storage, flood mitigation and water storage; water treatment and purification and habitats for biodiversity. There is increasing recognition that these services provide real economic values. Wetlands are affected by numerous threats including habitat loss and degradation, climate change, pollution, invasive species, overharvesting and disease. The most serious impact is from habitat loss and degradation caused by upstream water resource developments and conversion to agriculture, industry and transport, and urban development. The status of the distribution and extent of the world's wetlands remains poorly known, varying among countries. Wetland loss has varied internationally, with generally higher impacts in the Northern Hemisphere, with its long history of conversion to urban centres, ports and agriculture and yet there are increasing losses occurring in developing continents in the south. Wetland conservation needs to focus primarily on identification of priority areas for biodiversity conservation and legal protection, including Ramsar‐listing. Identification of wetland biodiversity hotspots for conservation should be an imperative, with associated Ramsar‐listing. There also needs to be effective protection of flow regimes. Mitigation of other deleterious processes, pollution, overharvesting, invasive species and disease, also remains particularly important. Conservation of wetlands remains especially challenging, given the importance of fresh water for human communities, industry and agriculture. Without effective conservation actions, mitigation of threats, rigorous risk assessment and acknowledgement of the value of wetland ecosystem services, wetland conservation will continue to lag behind conservation in other realms in protecting the Earth's biodiversity. Copyright © 2016 John Wiley & Sons, Ltd.

Dramatic variations in emergent wetland area in China's largest freshwater lake, Poyang Lake

Freshwater wetlands are important ecosystems experiencing rapid degradation around the world. As much as 64% of world's wetland area has been lost since 1900; the situation is even more serious in Asia, where land reclamation and anthropogenic modifications of rivers are increasing the rate of wetland disappearance. In this study, we provide a first complete estimation of daily Emergent Wetland Area (EWA) in Poyang Lake, China's largest freshwater lake, from 1955 to 2012. A wavelet analysis indicates a strong periodicity in the monthly EWA time series with two oscillations having a period of 12 and 60–72 months, respectively. A dramatic increase in mean annual EWA is detected since 2003, when the Three Gorges Dam (TGD) was completed, mainly due to the seasonal drying of 1078km2 of wetlands in October. It is found that the timing of wetland emergence during the dry season has been anticipated of one month, from November to October, since the establishment of TGD. It is argued that a significant increase in wetland exposure and an observable shift in the seasonal timing of flooding and drying will seriously degrade the wetland system and threaten the endangered migratory birds that inhabit it unless effective countermeasures are implemented.

Investigation of Influenza A, West Nile and Newcastle Disease Viruses in Birds from the Pantanal Wetlands of Mato Grosso, Brazil

The Pantanal is the world's largest wetland biome with a seasonal flood pulse that attracts a great diversity of birds, many of which are migratory. Birds can be natural reservoirs Influenza A, West Nile and Newcastle Disease viruses. However, the occurrence of carriers for these viruses in the Pantanal was not verified yet. The present study evaluated the occurrence of natural infection by Influenza A, WN and ND virus of birds in the municipality of Pocone, a subregion of the Pantanal in the state of Mato Grosso, Brazil. A total of 76 birds belonging to 11 orders and 20 families were captured using mist nets. The most representative order was Passeriformes, followed by the other nine orders, which included Columbiformes, Psittaciformes, Charadriiformes and Anseriformes. The most representative family was Thamnophilidae, with 16 individuals (21.0%), followed by the family Tyrannidae with 10 individuals (7.6%) and the family Furnariidae, with eight individuals (10.5%). The bird species were identified, and cloacal and tracheal swab samples were collected. The samples were subjected to RNA extraction and tested for the presence of the three agents by real-time polymerase chain reaction (qRT-PCR). All the sampled birds were considered healthy, had no clinical sign of infection, and were tested negative for the three viruses. Based on our findings, we can conclude that Influenza, West Nile and Newcastle Disease viruses were absent from the samples in this region of the Pantanal wetlands during the period of this study.

Access to and allocation of ecosystem services in Malaysia's Pulau Kukup Ramsar Site

This paper explores how the Ramsar Convention, a key multilateral environmental agreement for the world's wetlands, influences the allocation and use of ecosystem goods and services. Focusing on the world's second largest uninhabited mangrove island, Pulau Kukup, this study illustrates the social and ecological risks and opportunities surrounding protected wetlands. Interviews with, and observations of, nearby communities reveal that Pulau Kukup has continued to render regulatory, cultural, provisioning and supporting ecosystem services under different governance regimes and institutional arrangements. Under the current governance regime, national conservation agencies focus largely on conservation and have struggled to implement the principles of wise use as specified by the Ramsar Convention. Nevertheless, such strict local (formal) conservation rules restricting public access have improved the ecological integrity of the mangrove island, with little negative impact on the locals. While restrictions in access may be seen as a trade-off for local communities wishing to pursue cultural activities, tourism linked to the island's Ramsar designation has boosted the local economy. Despite these benefits, changes in property rights and growing influxes of tourists visiting the protected wetland may affect the long-term ecological integrity and the balance between wetlands, communities, livelihood options, and sustainability. Such challenges demand governance that recognises and responds to these emerging issues.

State of the World's Wetlands and Their Services to People: A Compilation of Recent Analyses

Ramsar Resolution XI.17 requested the Convention’s Scientific and Technical Review Panel to report on the state of the world’s wetlands and their services to people. As a contribution to this task, this Briefing Note summarizes and highlights for Contracting Parties and other decision makers key points from select scientific reports and articles published in 2013 and 2014. In particular, the Briefing Note discusses wetland status and trends, the loss of wetland ecosystem services and future steps for data collection and assessment. The negative trends shown by recent studies should serve as a call to Contracting Parties to avoid further wetland loss and degradation and to strengthen wetland assessment, monitoring and restoration.

Climate change archaeology: building resilience from research in the world's coastal wetlands

Climate change archaeology: building resilience from research in the world's coastal wetlands

Greenhouse Experimental Methods Towards in-situ Burial and Restoration of Contaminated Sites in Submerged Wetlands

As a result of commercial and industrial activit ies conducted in the absence of environmental regulations and enforcement in the past, sediments contaminated by organic compounds, heavy metals, and other potentially to xic chemicals have accu mulated in many of the world's deepwater and wet land environ ments. These sediment-borne contaminants can eventually become incorporated into aquatic food webs and adversely affect ecological receptors like benthic organisms and fish, and u ltimately pose a risk to hu man health. This laboratory research tested a commercial product AquaBlok TM (patented, composite-aggregate technology comprised of a solid core, an outer layer of clay material, and polymers) as an in-situ capping technology that could be used to remediate and/or manage contaminated sediments in the New Jersey Hackensack Meadowlands, a superfund site. In a greenhouse setting, tubs containing representative Meadowland marsh soil and water were capped with AquaBlok. This research not only examined the potential use of this product as an in-situ capping material and possible substrate for flora co lonization, but also examined the imp rovements of the same patented, clay mineral-based composite aggregate technology (SubmerSeed TM ) as an alternative to tradit ional means of wetland p lant propagation. At the end of a two-year period, both the sediment/cap and vegetation plant tissues were examined for metallic contaminants (including Cd, Cr, Cu, Pb, Hg, and Zn). Overall, capping provided a less contaminated substrate. Results indicated that AquaBlok cap alone did not allow contaminants in the sediment belo w to breakthrough. Nevertheless, vegetation colonization was restricted to a limited number of plant species. Furthermore, plants growing in AquaBlok were less robust with lower dry weight and s maller root system than plants growing in uncapped sediments despite the fact that their tissue contained smaller amounts of metallic contaminants. The improvements of the clay mineral-based composite aggregate technology (Sub merSeeds) as an alternative to trad itional means of plant propagation worked very well in successfully delivering aquatic plant seeds into permanently inundated conditions.

How wetland type and area differ through scale: A GEOBIA case study in Alberta's Boreal Plains

It is estimated that Canada comprises approximately 28% of the world's wetlands (~ 1.5 million km 2) providing essential ecological services such as purifying water, nutrient cycling, reducing flooding, recharging ground water supplies, and protecting shorelines. In order to better understand how wetland type and area differ over a range of spatial and thematic scales, this paper introduces a multi-scale geographic object-based image analysis (GEOBIA) approach that incorporates new object-based texture measures ( geotex) and a decision-tree classifier ( See5), to assess wetland differences through five common spatial resolutions (5, 10, 15, 20 and 30 m) and two different thematic classification schemes. Themes are based on (i) a Ducks Unlimited (DU: 15 class) regional classification system for wetlands in the Boreal Plain Ecosystem and (ii) the Canadian Wetland Inventory (CWI: 5 classes). Results reveal that the highest overall accuracies (67.9% and 82.2%) were achieved at the 10 m spatial resolution for both the DU and CWI classification schemes respectively. It was also found that the DU wetland types experienced greater area differences through scale with the largest differences for both classification schemes occurring in classes with a large treed component. Results further show that the inclusion of geotex channels (generated from dynamically sized and shaped window that measures the spatial variability of the wetland components composing a scene, rather than of individual pixels within a fixed sized window) improved wetland classification.

Implications of Rice Agriculture for Wild Birds in China

Abstract. Data on wild birds in rice fields in China are scarce. The potential significance of Chinese rice fields, which represent about 6% of the world's wetland area, is considerable but whether this potential is met is largely unknown. In this review, traditional and modern Chinese rice agriculture are compared, including detailing historical changes and their implications for wild birds. Traditional practices, with one crop each year and long periods of fallow flooding, provide greater benefit to biodiversity and species such as the Crested Ibis (Nipponia nippon). The method and alternatives, such as rice-fish, duck-rice and swidden agriculture, are contrasted with modern techniques which, through associated water regimes and chemical use, have been implicated in the decline of biodiversity and of species such as the Black-faced Spoonbill (Platalea minor). Agrochemical use is particularly pertinent because China is likely to have been the world's largest pesticide consumer since the mid-1990s, with u...