A Tale of Grass and Trees: Characterizing Vegetation Change in Payne’s Creek National Park, Belize from 1975 to 2019
A Tale of Grass and Trees: Characterizing Vegetation Change in Payne’s Creek National Park, Belize from 1975 to 2019
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草与树的故事：1975 年至 2019 年伯利兹佩恩溪国家公园的植被变化特征
作者：
Luke Blentlinger;H. Herrero
伯利兹的低地稀树草原是保护其生物多样性的重要地区。这项研究发生在佩恩溪国家公园（PCNP）在南部沿海平原的伯利兹。五氯苯酚和氯化萘保护各种陆地和沿海生态系统、独特的自然特征和野生动物。采用支持向量机（SVM）分类技术对PCNP的异质景观进行分类，以表征1975年，1993年，2011年和2019年遥感数据时间序列中的木本和非木本转化。结果表明，SVM分类器在这个小的热带稀树草原景观（平均整体准确率为91.9%）与输入变量的原始Landsat图像，归一化差异植被指数（NDVI），海拔和土壤类型表现良好。我们的变化轨迹分析表明，PCNP是一个相对稳定的景观，但在时间序列中，某些领域容易发生多次转换。木本植被主要出现在可变坡度和河岸带，养分供应增加。这项研究并没有显示广泛的木本转换PCNP，相反，在其他大陆的稀树草原正在发生的广泛的木本入侵。这些高性能的SVM分类地图和未来的研究将是一个重要的信息资源，对热带草原科学家和土地管理人员，使用适应性管理生态系统保护的中美洲热带草原植被动态。
The lowland savannas of Belize are important areas to conserve for their biodiversity. This study takes place in Payne’s Creek National Park (PCNP) in the southern coastal plain of Belize. PCNP protects diverse terrestrial and coastal ecosystems, unique physical features, and wildlife. A Support Vector Machine (SVM) classification technique was used to classify the heterogeneous landscape of PCNP to characterize woody and non-woody conversion in a time-series of remotely sensed data from 1975, 1993, 2011 and 2019. Results indicate that the SVM classifier performs well in this small savanna landscape (average overall accuracy of 91.9%) with input variables of raw Landsat imagery, the Normalized Difference Vegetation Index (NDVI), elevation, and soil type. Our change trajectory analysis shows that PCNP is a relatively stable landscape, but with certain areas that are prone to multiple conversions in the time-series. Woody vegetation mostly occurs in areas with variable slopes and riparian zones with increased nutrient availability. This study does not show extensive woody conversion in PCNP, contrary to widespread woody encroachment that is occurring in savannas on other continents. These high-performing SVM classification maps and future studies will be an important resource of information on Central American savanna vegetation dynamics for savanna scientists and land managers that use adaptive management for ecosystem preservation.