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Journal ArticleDOI

The Botany of Mangroves

01 Feb 1987-Taxon-Vol. 36, Iss: 1, pp 304
About: This article is published in Taxon.The article was published on 1987-02-01. It has received 1361 citations till now. The article focuses on the topics: Mangrove.
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Journal ArticleDOI
TL;DR: In this article, Saenger et al. reviewed the status of mangrove swamps worldwide and assessed the effect of human activities on mangroves in the coastal environment using satellite imagery.
Abstract: he mass media and scientific press have widely reported losses of tropical environments, such as fellingof rain forests and bleaching of coral reefs.This well-meritedattention has created a worldwide constituency that supportsconservation and restoration efforts in both of these threat-ened ecosystems. The remarkable degree of public aware-ness and support has been manifested in benefit rock concertsat Carnegie Hall and in the designation of ice cream flavorsafter rain forest products. Mangrove forests are another im-portant tropical environment,but these have received muchless publicity.Concern about the magnitude of losses of man-grove forests has been voiced mainly in the specialized liter-ature (Saenger et al. 1983, Spalding et al. 1997).Mangrove trees grow ubiquitously as a relatively narrowfringe between land and sea, between latitudes 25°N and30°S.They form forests of salt-tolerant species,with complexfood webs and ecosystem dynamics (Macnae 1968,Lugo andSnedaker 1974, Tomlinson 1986).Destruction of mangrove forests is occurring globally.Global changes such as an increased sea level may affect man-groves (Ellison 1993,Field 1995),although accretion rates inmangrove forests may be large enough to compensate for thepresent-day rise in sea level (Field 1995).More important,itis human alterations created by conversion of mangroves tomariculture,agriculture,and urbanization,as well as forestryuses and the effects of warfare, that have led to the remark-able recent losses of mangrove habitats (Saenger et al. 1983,Fortes 1988, Marshall 1994, Primavera 1995, Twilley 1998).New data on the magnitude of mangrove area and changesin it have become more readily available, especially with theadvent of satellite imagery and the Internet. Moreover, in-formation about the function of mangrove swamps, theirimportance in the sustainability of the coastal zone, and theeffects of human uses of mangrove forests is growing. Somepublished regional assessments have viewed anthropogenicthreats to mangrove forests with alarm (Ong 1982,Fortes 1988,Ellison and Farnsworth 1996),but reviews at the global scaleare dated (Linden and Jernelov 1980, Saenger et al. 1983).We collated and revised published information to reviewthe status of mangrove swamps worldwide.To assess the sta-tus of this major coastal environment, we compiled and ex-amined available data to quantify the extent of mangroveforest areas in different parts of the world,the losses of man-grove forest area recorded during recent decades, and therelative contributions by various human activities to theselosses.We first assessed current mangrove forest area in tropicalcountries of the world.It is difficult to judge the quality of thesedata in the published literature, because in many cases themethods used to obtain them were insufficiently described andthe associated uncertainty was not indicated. Much infor-mation based on satellite imagery is summarized in the

1,641 citations

Journal ArticleDOI
TL;DR: In this paper, a bottom-up approach derived from upscaling a compilation of published individual estimates of carbon burial in vegetated habitats (seagrass meadows, salt marshes, and mangrove forests) to the global level and a top-down approach derived derived from considerations of global sediment balance and the organic carbon content of vegeatated sediments was evaluated.
Abstract: . The carbon burial in vegetated sediments, ignored in past assessments of carbon burial in the ocean, was evaluated using a bottom-up approach derived from upscaling a compilation of published individual estimates of carbon burial in vegetated habitats (seagrass meadows, salt marshes and mangrove forests) to the global level and a top-down approach derived from considerations of global sediment balance and a compilation of the organic carbon content of vegeatated sediments. Up-scaling of individual burial estimates values yielded a total carbon burial in vegetated habitats of 111 Tmol C y-1. The total burial in unvegetated sediments was estimated to be 126 Tg C y-1, resulting in a bottom-up estimate of total burial in the ocean of about 244 Tg C y-1, two-fold higher than estimates of oceanic carbon burial that presently enter global carbon budgets. The organic carbon concentrations in vegetated marine sediments exceeds by 2 to 10-fold those in shelf/deltaic sediments. Top-down recalculation of ocean sediment budgets to account for these, previously neglected, organic-rich sediments, yields a top-down carbon burial estimate of 216 Tg C y-1, with vegetated coastal habitats contributing about 50%. Even though vegetated carbon burial contributes about half of the total carbon burial in the ocean, burial represents a small fraction of the net production of these ecosystems, estimated at about 3388 Tg C y-1, suggesting that bulk of the benthic net ecosystem production must support excess respiration in other compartments, such as unvegetated sediments and the coastal pelagic compartment. The total excess organic carbon available to be exported to the ocean is estimated at between 1126 to 3534 Tg C y-1, the bulk of which must be respired in the open ocean. Widespread loss of vegetated coastal habitats must have reduced carbon burial in the ocean by about 30 Tg C y-1, identifying the destruction of these ecosystems as an important loss of CO2 sink capacity in the biosphere.

1,145 citations

Book
01 Apr 1994
TL;DR: In a world of increasing atmospheric CO2, there is intensified interest in the ecophysiology of photosynthesis and more attention is being given to other aspects of carbon exchange and storage in natural ecosystems.
Abstract: In a world of increasing atmospheric CO2, there is intensified interest in the ecophysiology of photosynthesis and more attention is being given to other aspects of carbon exchange and storage in natural ecosystems. For example, how much will the photosynthesis of terrestrial and aquatic vegetation change as global CO2 increases? Are there major ecosystems, such as the boreal forests, which may become important sinks of CO2 and slow down the effects of anthropogenic CO2 emissions on climate? This volume reviews the progress which has been made in understanding photosynthesis in the past few decades at several levels of integration, from the molecular level to canopy, ecosystem and global scales.

886 citations

Journal ArticleDOI
TL;DR: In this article, the authors review 72 published articles to elucidate characteristics of biomass allocation and productivity of mangrove forests and also introduce recent progress on the study of MANGEO to solve the site and species-specific problems.

688 citations

Journal ArticleDOI
TL;DR: There is growing research interest in the ethnobiology, socio-economics and management of mangrove forests as discussed by the authors, with harvesting efforts and impacts concentrated in stands that are closer to settlements and easiest to access (by land or by sea).

687 citations

References
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Journal ArticleDOI
TL;DR: Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols used xiii 1.
Abstract: Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols Used xiii 1. The Importance of Islands 3 2. Area and Number of Speicies 8 3. Further Explanations of the Area-Diversity Pattern 19 4. The Strategy of Colonization 68 5. Invasibility and the Variable Niche 94 6. Stepping Stones and Biotic Exchange 123 7. Evolutionary Changes Following Colonization 145 8. Prospect 181 Glossary 185 References 193 Index 201

14,171 citations

Journal ArticleDOI
16 Apr 1965-Science
TL;DR: A method is described which permits measurement of sap pressure in the xylem of vascular plants, and finds that in tall conifers there is a hydrostatic pressure gradient that closely corresponds to the height and seems surprisingly little influenced by the intensity of transpiration.
Abstract: A method is described which permits measurement of sap pressure in the xylem of vascular plants. As long predicted, sap pressures during transpiration are normally negative, ranging from -4 or -5 atmospheres in a damp forest to -80 atmospheres in the desert. Mangroves and other halophytes maintain at all times a sap pressure of -35 to -60 atmospheres. Mistletoes have greater suction than their hosts, usually by 10 to 20 atmospheres. Diurnal cycles of 10 to 20 atmospheres are common. In tall conifers there is a hydrostatic pressure gradient that closely corresponds to the height and seems surprisingly little influenced by the intensity of transpiration. Sap extruded from the xylem by gas pressure on the leaves is practically pure water. At zero turgor this procedure gives a linear relation between the intracellular concentration and the tension of the xylem.

4,079 citations

Journal ArticleDOI
TL;DR: The objective was to establish an experimental procedure and show direct AFM measurements that unequivocally can be assigned as a mode of action for the conversion of NalK to Na6(SO4)(SO3) during the cycling process.
Abstract: INTRODUCTION 89 BACKGROUND: THE BASIC PHYSIOLOGY 91 Conclusions 9S ION RELATIONS 96' Ion Uptake and Osmotic Adjustment 96 Nutrient Uptake: NalK Specificity 99 Ion Distribution within the Plant 100 Ion Distribution within the Cell 100 Metabolic evidence 100 Physical measurements .... .... ......... ...... 104 Energetics 106 ROLE OF ORGANIC SOLUTES ........ 108 OrganiC Acids 108 Nitrogen Compounds 109 Carbohydrotes 110 CONCLUSIONS 114

1,959 citations