Benavides-Varela Catalina, Samper-Villareal Jimena, Cortés Jorge
Rev Biol Trop. 2016 Sep;64(3):955-64.
Despite the economic and environmental services that mangroves provide, they continue to be threatened by overexploitation, pollution, and land use change. Costa Rica has mangrove areas on the Pacific and Caribbean coasts, and cover has been declining since the 1980s. However, data on mangrove coverage are not continually updated and are often based on inaccurate estimates. It is therefore necessary to assess the current extension and variation of the mangrove cover in recent years, to determine changes. The mangrove cover was analyzed in two mangrove forests located in Bahía Culebra, North Pacific: Iguanita and Playa Panamá. For this, aerial photographs and satellite imagery were used to study changes for a 65 year period (1945-2010). Spatio-temporal changes were found in mangroves coverage, and adjacent forests and areas without vegetation. Lower mangrove cover occurred during the 1970s (28.4 ha in Iguanita and 4.8 ha in Playa Panamá); but increased in recent years (38.9 ha in Iguanita and 12.0 ha in Panamá). Changes in forest cover by the Iguanita and Playa Panama mangroves were related to the history of land use around Bahía Culebra. Before 1980, there was extensive and intensive cattle ranching, increasing the deforestation rate; after that year, these practices were abandoned and secondary forest coverage increased until 2000. To ensure the adequate protection of mangroves, it is not only important to protect mangrove forests, but it is also necessary to establish buffer zones on their surroundings, to mitigate and/or reduce possible impacts.
尽管红树林提供了经济和环境服务,但它们仍继续受到过度开发、污染和土地利用变化的威胁。哥斯达黎加在太平洋和加勒比海岸都有红树林区域,自20世纪80年代以来,其覆盖面积一直在下降。然而,红树林覆盖面积的数据并未持续更新,且往往基于不准确的估计。因此,有必要评估近年来红树林覆盖面积的当前范围和变化情况,以确定变化情况。对位于北太平洋库莱布拉湾的两片红树林——伊瓜尼塔和巴拿马海滩的红树林覆盖情况进行了分析。为此,使用了航拍照片和卫星图像来研究65年期间(1945 - 2010年)的变化。在红树林覆盖区域、相邻森林和无植被区域发现了时空变化。红树林覆盖面积在20世纪70年代较低(伊瓜尼塔为28.4公顷,巴拿马海滩为4.8公顷);但近年来有所增加(伊瓜尼塔为38.9公顷,巴拿马为12.0公顷)。伊瓜尼塔和巴拿马海滩红树林的森林覆盖变化与库莱布拉湾周边的土地利用历史有关。1980年之前,存在广泛且密集的养牛业,森林砍伐率上升;那一年之后,这些做法被放弃,次生林覆盖面积增加,直至2000年。为确保对红树林的充分保护,不仅要保护红树林森林,还必须在其周边建立缓冲区,以减轻和/或减少可能的影响。