A comparison of Colombian Pacific mangrove extent estimations: Implications for the conservation of a unique Neotropical tidal forest (original) (raw)
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Colombia has approximately 379,954 hectares of mangrove forests distributed along the Pacific Ocean and the Caribbean Sea coasts. Such forests are experiencing the highest annual rate of loss recorded in South America and, in the last three decades, approximately 40,000 hectares have been greatly affected by natural and, especially, human impacts. This study determined, by the use of Landsat multispectral satellite images, the evolution of three mangrove forests located in the Colombian Caribbean Sea: Malloquín, Totumo, and La Virgen swamps. Mangrove forest at Mallorquín Swamp recorded a loss of 15 ha in the period of 1985-2018, associated with alterations in forest hydrology, illegal logging, urban growth, and coastal erosion. Totumo Swamp lost 301 ha in the period 1985-2018 associated with changes in hydrological conditions, illegal logging, and increased agricultural and livestock uses. La Virgen Swamp presented a loss of 31 ha in the period of 2013-2018 that was linked to the construction of a roadway, alterations of hydrological conditions, illegal logging, and soil urbanization, mainly for tourist purposes. Although Colombian legislation has made efforts to protect mangrove ecosystems, human activities are the main cause of mangrove degradation, and thus it is mandatory for the local population to understand the value of the ecosystem services provided by mangroves.
Recent advances in understanding Colombian mangroves
Throughout the last 15 years, researchers at the National University of Colombia at Medellin have studied Colombian mangroves. Remote sensing, pollen analysis of superficial and deep sediments, Holocene coastal vegetation dynamics, sediment dating using 14 C and 210 Pb, sampling in temporary plots, sampling in temporary and permanent plots, and other techniques have been applied to elucidate long-and shortterm mangrove community dynamics. The studied root fouling community is structured by several regulatory mechanisms; habitat heterogeneity increases species richness and abundance. Fringe mangroves were related to Ca concentration in the soil and the increased dominance of Laguncularia racemosa and other nonmangrove tree species, while the riverine mangroves were associated with Mg concentration and the dominance of Rhizophora mangle. The seedling and mangrove tree distributions are determined by a complex gradient of natural and anthropogenic disturbances. Mangrove pollen from surface sediments and the existing vegetation and geomorphology are close interrelated. Plant pollen of mangrove and salt marsh reflects environmental and disturbance conditions, and also reveals forest types. Forest dynamics in both coasts and their sensitivity of to anthropogenic processes are well documented in the Late Quaternary fossil record. Our studies of short and long term allow us to predict the dynamics of mangroves under different scenarios of climate change and anthropogenic stress factors that are operating in Colombian coasts. Future research arises from these results on mangrove forests dynamics, sea-level rise at a fine scale using palynology, conservation biology, and carbon dynamics.
Mangrove Forests in Ecuador: A Two-Decade Analysis
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Mangroves are one of the most important ecosystems especially due to the services they provide, but in contrast are one of the most threatened by human activities at a global level. In Ecuador, mangrove forests are currently fragile and threatened due to the great anthropic pressure, which has largely reduced the area they occupy. However, there is already evidence that certain actions are contributing both to their conservation and the recovery of the lost mangrove area. In this study, we assessed the multitemporal dynamics of changes in mangrove cover in four coastal provinces of the country over a period of 20 years (1998–2018) based on remote sensing data analyzed using GIS tools. Our results showed that the area affected by mangrove forest destruction reached its maximum during the 1998–2010 period, when 4.56% (194.57 km2) of the mangrove forest was lost. This situation especially affected the provinces of El Oro and Guayas. The main cause for the loss of mangrove cover was the...
Conserving Latin American and Caribbean mangroves: issues and challenges
Madera y Bosques, 2002
This is a literature review of the distribution, salient features, uses, and conservation of mangroves in the Caribbean and Latin America. These ecosystems have played a vital role in the development of the region and their value increases as tropical countries develop and commercialize their coastal zones. Unfortunately, markets ignore or underestimate the value of products and non-market services from mangroves. Science informs and improves the effectiveness of the conservation of mangroves. Professional management with participation of all sectors of society also benefits the conservation of mangroves. Understanding mangrove ecosystems requires consideration of multiple spatial and temporal scales and attention to paradoxes that can lead to ineffective conservation measures. The review includes guidelines for mangrove restoration and conservation.
Mangrove timber use as an ecosystem service in the Colombian Pacific
Hydrobiologia, 2017
Mangroves provide ecosystem services for local communities. However, in coastal systems it is yet unknown how human settlements are directly interacting with mangroves. We assessed the use of mangroves as an ecosystem service at Málaga and Buenaventura bays, on the Colombian Pacific coast, by interviewing local communities and examining the impact of mangrove harvest on the structure of the forest, an often overlooked effect. Results showed that mangroves are mainly harvested for their wood. Rhizophora spp. are the main source of wood for fuel purposes, whereas Mora oleifera (Triana ex Hemsl.) Ducke, a mangrove associate, provides 100% of the wood used for the construction of stilt houses. The selective extraction of these species has altered the composition and structure of the forest. Sample sites undergoing harvest have relatively low densities of mangroves; however, one site at Quebrada Valencia shows signs of copious regeneration ([9000 seedlings/ha). Due to the importance of mangroves for the subsistence of coastal communities, and the threat that mangroves are exposed to in Colombia, the management of mangroves should be a priority. Managers must address the sustainability of critical species as part of conservation strategies in order to maintain ecosystem services for local communities.
Mangroves and people: Lessons from a history of use and abuse in four Latin American countries
From native pre-Columbian subsistence economies to the modern global economy, mangroves have played an important role providing goods and services to human societies for millennia. More than 90% of the world's mangroves are located in developing countries, where rates of destruction are increasing rapidly and on large scales. In order to design effective conservation strategies, it is critical to understand the natural dynamics and anthropogenic drivers of these coastal wetland habitats. We use retrospective techniques to reconstruct mangrove forest history in the Eastern Tropical Pacific. We examine available, present day estimates of mangrove area and evaluate the representation of mangroves in the protected area systems of Costa Rica, Panama, Colombia and Ecuador, evaluating existing policies regarding mangroves. Archaeozoological evidence shows that mangroves were exploited for many thousands of years by pre-Columbian societies. Post-conquest deforestation prevailed during the next 400 years. Since 1990, despite increasingly positive attitudes towards mangroves and their inclusion in protected areas and conservation policies, mangrove cover has continued to decline due to expanding human activities (agriculture, aquaculture, coastal development), even in the presence of laws prohibiting their removal. Here we provide an historical ecology baseline of mangroves in the Eastern Tropical Pacific, from which to view current trends and map future trajectories. Given the myriad negative consequences of mangrove loss recorded worldwide, and the strong ecological connectivity of the region, developing effective strategies for mangrove management at an appropriate scale will be paramount to protect coastal livelihoods and biodiversity.
On the reliability of the data of the extent of mangroves: A case study in Mexico
Ocean & Coastal …, 2008
We analyze part of the available information on the extent of mangroves and discuss the consistency of the records, because of the importance of mangrove cover at both a global and local scale and because of the differences among time-series figures and estimated trends, with special emphasis on the mangroves in Mexico. The analysis includes the most important scientific and technical reports on the surface of this cover on a national scale. The methods reported in literature were compared when possible, because many cases were poorly described and the accuracy of the data was not indicated. Finally we discuss the possible implications of using the statistics of the extent of the mangroves on mangrove deforestation rates estimated for Mexico when these data have a high degree of uncertainty.
Mangroves are ecologically important and extensive in the Neotropics, but they are visibly threatened by selective logging and conversion to pastures in the Southern Caribbean. The objective of this paper was to summarize the impacts of both threats on forest structure, species composition, aboveground biomass and carbon reservoir, species introgressions, and benthic fauna populations by collating past and current data and by using an interdisciplinary approach in the Urabá Gulf (Colombia) as a case study. Mangroves in the Eastern Coast have been decimated and have produced unskewed tree-diameter (DBH) distributions due to the overexploitation of Rhizophora mangle for poles (DBH range: 7–17 cm) and of Avicennia germinans for planks and pilings (DBH > 4 0 cm). Selective logging increased the importance value of the light-tolerant white mangrove Laguncularia racemosa, also increasing biomass and carbon storage in this species, thus offsetting reductions in other species. Introgressions (cryptic ecological degradation) by L. racemosa and Acrostichum aureum (mangrove fern) and low densities of otherwise dominant detritivore snails (Neritina virginea) were observed in periurban basin mangroves. Finally, basin mangroves were more threatened than fringing mangroves due to their proximity to expanding pastures, villages, and a coastal city.