Utilization of mangrove wood products around mida creek (Kenya) amongst subsistence and commercial users

Mida Creek (Kenya) comprises mangrove forests and other marine resources that are of economic, ecological, and environmental importance to the local village communities. In total 116 households (100 of which could be used for numerical analysis), which are estimated to correspond to a coverage of ca. 30% of the total Mida Creek population, were interviewed to assess the human reliance on mangrove resources in Mida Creek. The survey indicates that mangroves are a major resource of wood for house construction, fuel wood, charcoal, and boat building. Minor uses of mangrove products include pharmaceutical and medicinal applications, tanning material, and furniture making. Rhizophora mucronata, Ceriops tagal, and Bruguiera gymnorrhiza are the major resources for house construction and fuel wood, while Sonneratia alba and Xylocarpus granatum were reported to be useful for boat building and medicinal uses respectively. The survey further describes harvesting activities and house construction, and reveals species preferences within this one particular use. As a result of depletion of the supply and the banning of mangrove harvesting, the local people are turning to other wood materials and to poaching. In our view, local utilization patterns rather than global usefulness data are required to establish a conservation policy of both mangroves and users’ subsistence requirements.     

The current status of mangroves along the Kenyan coast: a case study of Mida Creek mangroves based on remote sensing

Mangroves form a unique ecosystem of limited extent covering an area of about 53 000 ha along the Kenyan coast which need protection from overexploitation. Background information on the areal extent and status of these mangroves is limited and makes their protection and management difficult.A model study has been carried out on the Mida Creek mangroves based on a double sampling approach starting with SPOT multispectral satellite imagery followed by ground checks to provide information on species composition, density and distribution of mangroves. The utilization of mangroves and uses around and within the mangroves were determined.During this study, seven mangrove species were identified in Mida Creek, namely:Avicennia marina, Bruguiera gymnorrhiza, Ceriops tagal, Rhizophora mucronata, Sonneratia alba, Xylocarpus granatum andLumnitzera racemosa. This report briefly outlines the present utilisation of mangrove species. It is recommended that a multidisciplinary management plan be developed in order to conserve and manage the mangroves of Kenya on a sustainable yield basis.     

Poverty and institutional management stand-off: a restoration and conservation dilemma for mangrove forests of Tanzania

Mangrove forests of Tanzania are reserved by law, but the capacity to effectively enforce this institution has remained far from reach and mangrove forests continue to be exploited as cheap sources of wood and forest land for other uses. Often, the rural poor who depend on mangroves for their subsistence are pointed out by the state institutions as culprits of the degradation. Promisingly though, this paradigm is being offset by the emerging positive view about human proclivity for caring and nurturing common resources. Traditional and community based forest management practices are emerging as appropriate alternatives to state control and institutional arrangement for ensuring sustainable management of forest resources. Nonetheless, community based management has not yet been robustly implemented for mangrove forests in Tanzania. Retrospectively, this paper argues that nationalization of mangrove forests has not been successful in reversing mangrove degradation. The experiences have instead been the frictions between people and the state, as desperate rural poor continue to plunder on and make a living at the expense of mangrove forests. The paper exemplify how policy failure, weak or dysfunctional state institutions in Tanzania compounded by little participatory awareness and self commitment are ruining the restoration and conservation initiatives.     

基于多源遥感的红树林监测

红树林是生长在热带以及亚热带海岸潮间带上的生态群落, 其生产力高, 固碳能力强, 对保持海岸带生物多样性具有十分重要的价值。本文介绍了利用多源遥感数据监测红树林的一些主要研究内容, 分为3个方面: (1)在时空模式研究方面, 利用高空间分辨率影像像素和对象结合的方法对红树林树种进行分类以及利用Landsat影像对红树林进行动态变化监测并分析其驱动因素; (2)在结构参数研究方面, 利用无人机多光谱数据及地面激光雷达数据对红树林叶面积指数进行反演; (3)在生理生化参数研究方面, 探讨了红树林叶绿素含量对淹没状况的响应、互花米草(Spartina alterniflora)入侵是否影响红树林光能利用率, 以及光化学反射指数(photochemical reflectance index, PRI)与光能利用率(light use efficiency, LUE)的关系。上述系列研究为提取红树林相关信息要素时如何选择合适的分析方法提供了有力的参考, 强调了遥感在研究红树林时空模式, 提取结构参数和生物生化参数监测的有效性, 从而更好地促进红树林生态系统的生物多样性保育工作。     

Ethnobiology, socio-economics and management of mangrove forests: A review

There is growing research interest in the ethnobiology, socio-economics and management of mangrove forests. Coastal residents who use mangroves and their resources may have considerable botanical and ecological knowledgeable about these forests. A wide variety of forest products are harvested in mangroves, especially wood for fuel and construction, tannins and medicines. Although there are exceptions, mangrove forest products are typically harvested in a small-scale and selective manner, with harvesting efforts and impacts concentrated in stands that are closer to settlements and easiest to access (by land or by sea). Mangroves support diverse, local fisheries, and also provide critical nursery habitat and marine productivity which support wider commercial fisheries. These forests also provide valuable ecosystem services that benefit coastal communities, including coastal land stabilization and storm protection. The overlapping of marine and terrestrial resources in mangroves creates tenure ambiguities that complicate management and may induce conflict between competing interests. Mangroves have been cut and cleared extensively to make way for brackish water aquaculture and infrastructure development. More attention is now given to managing remaining forests sustainably and to restoring those degraded from past use. Recent advances in remotely sensed, geo-spatial monitoring provide opportunities for researchers and planners to better understand and improve the management of these unique forested wetlands.     

The ecology of mangrove conservation & management

Despite the recent better understanding and awareness of the role of mangroves, these coastal forest communities continue to be destroyed or degraded (or euphemistically reclaimed) at an alarming rate. The figure of 1% per year given by Ong (1982) for Malaysia can be taken as a conservative estimate of destruction of mangroves in the Asia-Pacific region. Whilst the Japanese-based mangrove wood-chips industry continues in its destructive path through the larger mangrove ecosystems of the region, the focus of mangrove destruction has shifted to the conversion of mangrove areas into aquaculture ponds and the consequences of the unprecedented massive addition of carbon dioxide to the atmosphere by post industrial man.Mangroves are non-homogeneous; characterised by distinct vegetative zones that occupy the interface between land and sea and dynamically interacting with the atmosphere above as well as with the influences of the adjacent land and sea. The conservation of mangroves should thus include not only the various vegetation and tidal inundation zones but also the adjacent marine and terrestrial areas (including the water catchment area).On the current concern with global climate change, it is pointed out that relative sea level change is very much site dependent. For effective planning and management, it is vital to know if a particular site is stable, rising or sinking so efforts should be directed to find suitable methods for determining this. However, should rapid relative sea level rise take place, there is very little likelihood of saving mangroves whose landward margins have been developed by man, a fact to bear in mind when selecting sites for conservation. The Matang mangroves of Malaysia is rare case of successful sustainable management of a tropical rain forest. Although the tools of management are available they are not widely applied. We particularly urge the Japanese mangrove wood-chips industry to look to long term sustainable use rather than short term gains. A suggestion is made to appeal to the new Government of Japan to take the lead in environmental friendliness especially to the rain forests of the Asia-Pacific region.     

Ecology and systematics of mangrove crabs of the genus Perisesarma (Crustacea: Brachyura: Sesarmidae) from East Africa

East Africa has a reduced mangrove crab species richness when compared to Asian mangroves. To date, only one species of Perisesarma de Man, 1895 has been reported in East Africa, despite more than 30 years of mangrove research in this region. Based on morphology, colour, mtDNA and behaviour, we describe a new species of Perisesarma from Kenya, P. samawati sp. nov. Surprisingly, when comparing molecular data from other species within this genus, P. samawati sp. nov. and the sympatric P. guttatum (A. Milne Edwards, 1869) are not sister species. Some aspects of the ecology of P. guttatum and P. samawati sp. nov. are compared and the differences discussed. Additionally, we compare P. samawati sp. nov. with the ecological literature of a possible sister species P. eumolpe de Man, 1895 from Malaysian mangroves. Our findings suggest that the new species is an ecologically important species in East African mangroves.  © 2004 The Linnean Society of London, Zoological Journal of the Linnean Society , 2004, 141 , 435–445.     

Status and exploitation of the mangrove and associated fishery resources in Zanzibar

The distribution and growth forms of the mangroves on Zanzibar island (Unguja and Pemba) were investigated. Pemba island, with approximately 12000 ha of mangroves, had nine species; and Unguja island, with 6 000 ha, had eight. Average cropping intensities in Pemba island varied between 350–1937 cut plants per ha while in Unguja these were between 777–3567 cut plants per ha. In Pemba, mangrove forests were relatively less heavily exploited compared to those in Unguja, where clear felling was common. Charcoal, lime and salt production are the major activities which involve heavy utilization of mangrove wood.The fishery resources (shellfish and finfish) associated with the mangrove vegetation were also investigated by examining the composition of fish catches at landing stations in mangrove as well as nonmangrove zones of fishing districts. A survey on the fauna associated with mangrove forests was also conducted. A number of the local commercial fish species were found to be associated with the mangrove vegetation. The fishes of the genusLethrinus and the rabbit fishSiganus were found to constitute the bulk of the fish caught from waters adjacent to mangroves using movable traps. The molluscPyrazus sp., which is commonly used by the local people for food and bait, was found only in the mangroves.     

The assessment of mangrove biomass and carbon in West Africa: a spatially explicit analytical framework

Mangrove forests are highly productive and have large carbon sinks while also providing numerous goods and ecosystem services. However, effective management and conservation of the mangrove forests are often dependent on spatially explicit assessments of the resource. Given the remote and highly dispersed nature of mangroves, estimation of biomass and carbon in mangroves through routine field-based inventories represents a challenging task which is impractical for large-scale planning and assessment. Alternative approaches based on geospatial technologies are needed to support this estimation in large areas. However, spatial data processing and analysis approaches used in this estimation of mangrove biomass and carbon have not been adequately investigated. In this study, we present a spatially explicit analytical framework that integrate remotely sensed data and spatial analyses approaches to support the estimation of mangrove biomass and carbon stock and their spatial patterns in West Africa. Forest canopy height derived from SRTM and ICESat/GLAS data was used to estimate mangrove biomass and carbon in nine West African countries. We developed a geospatial software toolkit that implemented the proposed framework. The spatial analysis framework and software toolkit provide solid support for the estimation and relative comparisons of mangrove-related metrics. While the mean canopy height of mangroves in our study area is 10.2 m, the total biomass and carbon were estimated as 272.56 and 136.28 Tg. Nigeria has the highest total mangrove biomass and carbon in the nine countries, but Cameroon is the country with the largest mean biomass and carbon density. The resulting spatially explicit distributions of mangrove biomass and carbon hold great potential in guiding the strategic planning of large-scale field-based assessment of mangrove forests. This study demonstrates the utility of online geospatial data and spatial analysis as a feasible solution for estimating the distribution of mangrove biomass and carbon at larger or smaller scales.     

全球红树林时空变化及演变趋势

红树林是全球重要的生态系统,了解红树林的时空变化特征及演变趋势对开展红树林的保护、恢复及可持续管理具有重要意义。基于谷歌地球工程(Google Earth Engine,GEE)云平台,利用全球红树林分布数据和陆地卫星(Landsat)系列光学影像特征指数数据,结合Theil-Sen中值趋势分析、Mann-Kendall检验、Hurst指数等方法,分析了全球红树林的时空分布特征、时空演变趋势及其可持续特征。结果表明:1990-2020年全球红树林面积呈先下降后上升趋势,总面积减少52174.18km²,年平均流失率达1.2%,红树林面积减少最多的地区为东南亚,其次为澳大利亚和新西兰、南美洲和东南非洲;红树林呈退化趋势变化的面积(81.44%)明显多于改善区域的面积(17.43%),其中澳大利亚和新西兰的退化趋势最为明显;2015-2020年全球红树林变化趋势有所改善,有73.85%的区域在未来是可持续的,持续改善区域面积(38.58%)大于持续退化区域面积(33.06%),且改善区域的可持续性明显高于不可持续性,表明2020年之后全球红树林整体上呈改善趋势变化。全球红树林时空变化特征和演变模式,可为生物多样性保护、沿海经济发展、生态环境的可持续改善提供重要支撑,对评估联合国2030可持续发展目标实现的状况具有重要影响。     

The implications of harvesting on the population structure and sediment characteristics of the mangroves at Mngazana Estuary,Eastern Cape,South Africa

The Mngazana Estuary has the third largest area of mangroves in South Africa (118 ha) and one of the main environmental threats is the cumulative effects of long term small scale harvesting from local communities. This study investigated the change in aerial cover of the mangrove forest over time and assessed the effect of harvesting on the microenvironment and the population structure of Rhizophora mucronata (preferred harvested species) in both harvested and non-harvested sites. In 1982 there were 150 ha of mangroves of all species and since then 32 ha (21%) of the forest area has been lost. Areas of the estuary where mangroves have been completely removed showed significant differences in sediment characteristics. Changes in population size, ratios of adult trees to juveniles (harvested sites—1:5.5, non-harvested sites 1:3.4) and significant differences in height structure are some of the indications that harvesting is affecting the mangrove populations. Results show that while it is necessary to suggest proposals aimed at the sustainable use of the Mngazana mangroves, it is equally important in the short-term to make available alternative sources of materials to replace mangrove poles for building. The formation of the Mngazana Mangrove Management Forum provides an ideal opportunity to drive Participatory Forest Management (PFM) but this would require scientific and management support. The data shown here will provide ecological information required for PFM.     

Subtropical Brazilian mangroves as a refuge of crab (Decapoda: Brachyura) diversity

This study characterized seven mangrove areas of different sizes, located on the southeastern Brazilian coast, with respect to their sediment and vegetation features. We also estimated the richness and composition of the brachyuran assemblages in these mangroves. Crab, vegetation and sediment data were collected during low tide. The larger mangroves showed richer and complex forests, and may be more ecologically stable than smaller mangroves. Twenty-eight species of crabs were recorded, members of nine families: Panopeidae, Pinnotheridae, Gecarcinidae, Grapsidae, Sesarmidae, Varunidae, Ocypodidae, Ucididae, and Portunidae. Ocypodoidea predominated over Grapsoidea in the smaller mangrove areas in pioneer stages of forest establishment, whereas the opposite was recorded for larger and more stable mangroves, where the forest can reach advanced stage of development. Comprido is a small mangrove, but its crab assemblage was similar to the larger ones, probably because of other factors not investigated here (e.g., megalopa settling rate). This study provided basic knowledge for developing conservation strategies for vulnerable mangrove ecosystems.     

红树林生态系统遥感监测研究进展

随着现代遥感技术的迅速发展,遥感监测已经成为红树林生态系统变化监测的重要手段和方法。从遥感技术在生态系统变化监测应用领域入手,综述了国内外红树林遥感监测的发展历程,系统总结了遥感技术在红树林湿地动态、种间分类、群落结构(叶面积指数、冠幅、树高等)、生物量、灾害灾情(病虫害、风暴潮等)、景观格局动态、驱动力、红树林湿地保护与管理等领域应用现状,归纳了不同应用领域遥感监测的理论、方法及研究现状。指出我国在红树林遥感监测中存在的不足。提出红树林遥感监测应在分类标准体系规范化、分类精度提升、红树林生态学特征参数(物种多样性、优势度等)、生态系统环境空间演变过程及遥感监测的尺度效应方面加大研究力度。充分发挥区域综合监测模型在红树林生态系统变化遥感监测中的作用。     

Assessment of mangrove management alternatives in village-fringe forests of Indian Sunderbans: resilient initiatives or short-term nature exploitations?

The village-fringe mangroves throughout the Indian Sunderbans have become ecologically fragile due to decades of unsustainable utilization practices and changes in hydro-geomorphic conditions. These mangroves are generally managed by the state-run Forest Department, community institutions and non-governmental organizations either separately or in collaboration. This paper attempts to assess the forest health of three such mangrove sites managed by these different institutions using quantitative vegetation surveys. Transformations of land use and land cover patterns of these sites from 2003 to 2013 have also been analyzed by geospatial techniques. Moreover, a qualitative estimation of the products and services provided by these mangroves was performed through participatory appraisals among the local forest dependents to comprehend the level of economic sustenance achieved. Results indicate that the overall performance of the site managed by a non-governmental organization in collaboration with local forest dependents was better than the other two sites managed by Forest Department and joint state-community institution respectively. Proper recognition of the causes of forest degradation and subsequent creation of zonal plantations with respect to species associations and utilization patterns were identified as the prime determinants of comparative success of the former site. Restructuring of community institutions by strengthening participation of actual forest dependents in decision making was suggested to be beneficial for mangrove restoration of sites performing poorly. In general, adaptation of collaborative approaches towards addressing the issues of tenure rights, legitimate sharing of mangrove produces and services, conflict resolutions among and within these institutions were found to be imperative for resilient management of these mangroves.     

Recognition of co-existence pattern of salt marshes and mangroves for littoral forest restoration

Climate-change driven sea level rise causes a increase in salinity in coastal wetlands accelerating the alteration of the species composition. It triggers the gradual extinction of species, particularly the mangrove population which is intolerant of excessive salinity. Thus despite being crucial to a wide range of ecosystem services, mangroves have been identified as a vulnerable coastal biome. Hence restoration strategy of mangroves is undergoing rigorous research and experiments in literature at an interdisciplinary level. From a data-driven perspective, analysis of mangrove occurrence data could be the key to comprehend and predict mangrove behavior along different environmental parameters, and it could be important in formulating management strategy for mangrove rehabilitation and restoration. As salt marshes are the natural salt-accumulating halophytes, mitigating excessive salinity could be achieved by incorporating salt-marshes in mangrove restoration activities. This study intends to find a novel restoration strategy by assessing the frequent co-existence status of salt marshes, with the mangroves, and mangrove associates in different zones of degraded mangrove patches for species-rich plantation. To achieve this, we primarily design a novel methodological framework for the practice of knowledge discovery concerning the coexistence pattern of salt marshes, mangroves, and mangrove associates along with environmental parameters using a data mining paradigm of association rule mining. The proposed approach has the capability to uncover underlying facts and forecast likely facts that could automate the study in the field of ecological research to comprehend the occurrence of inter-species relationships. Our findings are based on published data gathered on the Sundarban Mangrove Forest, one of the world’s most important littoral forests. The existing literature reinforces the findings that include all the sets of frequently co-occurring mangroves, their associates, and salt marshes along the salinity gradient of coastal Sundarbans. A detailed understanding of the occurrence patterns of all these, along with the environmental variables, would be able to promote decision-making strategy. This framework is effective for both academia and stakeholders, especially the foresters/ conservation planners, to regulate the spread of salt marshes and the restoration of mangroves as well.     

Differentiation between true mangroves and mangrove associates based on leaf traits and salt contents

Aims Mangrove species are classified as true mangroves and mangrove associates. However, as for some fringe species found mainly on the landward transitional zones of mangroves, no consensus among scientists could be reached in favor of this classification and much debate arises. We hypothesized that true mangroves differ from mangrove associates physiologically and ecologically in their ability to survive in mangrove environment.Methods To test this hypothesis, leaf structural traits and osmotic properties were used to describe variation in 33 mangrove species (17 true mangroves, 6 mangrove associates and 10 controversial species).Important findings Specific leaf area (SLA) of true mangroves as well as leaf nitrogen concentration on a leaf mass (Nmass) were lower than that of mangrove associates; leaf succulence was, in general, twice as high in true mangroves compared to mangrove associates; true mangroves accumulated 8–9 times more Na and Cl than mangrove associates and the former had K/Na ratios <0.5, but the latter had K/Na ratios>0.5. These results indicated that true mangroves differed reliably from mangrove associates in leaf traits and osmotic properties. True mangroves are true halophytes and mangrove associates are glycophytes with certain salt tolerance. Combining distribution pattern information, the 10 controversial species were reclassified.     

Challenges of a transition to a sustainably managed shrimp culture agro-ecosystem in the Mahakam delta,East Kalimantan,Indonesia

Around 1990, when in other countries mangrove protection took off, massive conversion of mangrove forest into shrimp ponds started in the Mahakam delta. To identify constraints to and options for sustainable management we analysed institutions and constraints with stakeholders. In 3 sites we used participatory tools and a complementary survey to assess the livelihood framework. Since 1970, ponds for shrimp farming gradually replaced 75% of mangrove forested area. After 2004, recovery of mangrove took off, as, mainly due to low shrimp yields, ponds were abandoned. In 2008, 54% of the delta was dedicated to ponds for shrimp production. Around 80% of livelihood activities of pond-farmers, pond caretakers, and fishermen was related to mangroves. The involvement of men and women in these activities varied between sites and types. Poor households depended more on mangroves. Most activities resulted in seasonal income peaks; only a few activities resulted in a full daily livelihood. Ponds, on the other hand, provide 50% of households’ livelihood, but this remains vulnerable in the context of the risky shrimp production. Skewed land holding, unequal sharing of benefits, competing claims and vested interests of stakeholders pose a great challenge to a transition to a more sustainable use of the mangrove area. In particular, ponds located on peat soils are non-sustainable and would require full restoration into mangrove; ponds on other soils could best be transformed into a mixed mangrove-pond system using a ‘green-water’ technology.     

Local Management of Mangrove Forests in the Philippines: Successful Conservation or Efficient Resource Exploitation?

Recent environmental narratives suggest that local people are effective stewards of forest resources. Local restoration and management of mangrove forests, in particular, are now widely advocated as a solution to achieve both economic and environmental conservation goals. This paper presents findings from a study of 2 coastal sites in the Philippines that are renowned and often showcased as success stories in community-based, mangrove reforestation and management. These cases are especially intriguing because local tree planting and management emerged in both areas long before governments and nongovernment organizations began to promote such activities. These management systems are a successful economic innovation in that planted mangroves protect homes and fish pond dykes from wave and wind damage, and the production of high-value construction wood is dramatically enhanced through intensive plantation management. Mangrove plantations are an efficient alternative to harvesting from unplanted, natural mangroves and their spread may reduce harvesting pressures on existing forests. However, mangrove plantations are structurally and compositionaly very different from unplanted forests, a finding of particular concern given that such plantations are increasingly encroaching into and replacing natural forests. Furthermore, planted forests are not typically viewed by planters in terms of their environmental conservation values and are frequently cut and cleared to make space for alternative uses, especially fish farming and residential settlement. The suggestion that these local mangrove management systems are successful for conservation thus needs to be qualified.     

Can mangroves keep pace with contemporary sea level rise? A global data review

Coastal vegetated wetlands such as mangrove forests provide multiple ecosystem services, though are potentially threatened by contemporary accelerated sea level rise (SLR), in addition to other immediate threats such as agriculture and coastal development. Several studies have revealed that mangroves are able to adapt to, and keep pace with local relative SLR through vertical surface elevation change (SEC), however data are lacking, with often only surface accretion rate (SAR) data available. We systematically review published studies of SEC and SAR from globally distributed monitoring sites using meta-analysis, and compare them with the Intergovernmental Panel on Climate Change Fifth Assessment Report (IPCC AR5) SLR scenarios. Hydro-geomorphic setting plays an important role, with basin mangroves potentially less vulnerable to SLR through land building processes. We find that SAR in both basin and fringe mangroves can cope with low SLR scenario (RCP 2.6) throughout the 100 years projection period. However, SAR can only keep pace with high SLR scenario (RCP 8.5) up to year 2070 and 2055 in basin and fringe mangrove settings respectively. These were associated with potential sediment accumulation of 41 cm and 29 cm respectively from the baseline. Mangrove degradation promoted lowering trends of SEC, while mangrove management such as rehabilitation practice stimulated positive trends of SEC. Mangrove ecosystems may be vulnerable to contemporary SLR in small island locations such as the Caribbean, East Africa and parts of the Indo-Pacific that are dominated by fringe mangroves and where SEC cannot keep pace with both low and high IPCC AR5 SLR scenarios. A global expansion of current mangrove surface elevation monitoring effort is urgently needed in order to better assess the vulnerability of mangroves, and the factors affecting their resiliency in the face of rising sea levels.     

Using expert knowledge and modeling to define mangrove composition,functioning, and threats and estimate time frame for recovery

Mangroves are threatened worldwide, and their loss or degradation could impact functioning of the ecosystem. Our aim was to investigate three aspects of mangroves at a global scale: (1) their constituents (2) their indispensable ecological functions, and (3) the maintenance of their constituents and functions in degraded mangroves. We focused on answering two questions: “What is a mangrove ecosystem” and “How vulnerable are mangrove ecosystems to different impacts”? We invited 106 mangrove experts globally to participate in a survey based on the Delphi technique and provide inputs on the three aspects. The outputs from the Delphi technique for the third aspect, i.e. maintenance of constituents and functions were incorporated in a modeling approach to simulate the time frame for recovery. Presented here for the first time are the consensus definition of the mangrove ecosystem and the list of mangrove plant species. In this study, experts considered even monospecific (tree) stands to be a mangrove ecosystem as long as there was adequate tidal exchange, propagule dispersal, and faunal interactions. We provide a ranking of the important ecological functions, faunal groups, and impacts on mangroves. Degradation due to development was identified as having the largest impact on mangroves globally in terms of spatial scale, intensity, and time needed for restoration. The results indicate that mangroves are ecologically unique even though they may be species poor (from the vegetation perspective). The consensus list of mangrove species and the ranking of the mangrove ecological functions could be a useful tool for restoration and management of mangroves. While there is ample literature on the destruction of mangroves due to aquaculture in the past decade, this study clearly shows that more attention must go to avoiding and mitigating mangrove loss due to coastal development (such as building of roads, ports, or harbors).