ABSTRACT

Floodplain wetlands are among the most productive and biodiverse ecosystems on Earth and provide a major subsidy of food resources for consumers in river systems. The basal energy source for those consumers in many systems comes from aquatic algal production influenced by different characteristics of the floodplain environment. Our aim was to estimate relationships between algal productivity and environmental variables in the channels and wetlands of the Mitchell River floodplain in tropical Australia. We measured physical, chemical, and biological variables in a range of different wetland types (palustrine, lacustrine, and riverine) and different habitat types (emergent macrophytes, floating macrophytes, submerged macrophytes, and open water). The most productive areas were found among riverine wetlands and submerged habitats. The statistical models showed that habitat type and turbidity alone can predict algal productivity with reasonable accuracy (pseudo-R² = 0.35, n = 63). Importantly, those attributes can be measured using remote sensing, and hence the model can be used to predict algal productivity over wider spatial scales and identify important “hotspot” areas of primary productivity that sustain aquatic food webs. Through this approach we can inform current conservation and water planning frameworks to manage the impact of human development on the productivity of wetlands at large spatial scales.

摘要

漫滩湿地是地球上生产力和生物多样性最高的生态系统之一，为河流系统中的消费者提供了主要的食物资源补贴。许多系统中这些消费者的基础能源来自受洪泛区环境不同特征影响的水生藻类生产。我们的目的是估计热带澳大利亚米切尔河漫滩的河道和湿地中藻类生产力与环境变量之间的关系。我们测量了一系列不同湿地类型（沼泽、湖泊和河流）和不同栖息地类型（新兴植物、漂浮植物、沉水植物和开放水域）的物理、化学和生物变量。在河流湿地和水下栖息地中发现了生产力最高的地区。R ²  = 0.35，n  = 63）。重要的是，这些属性可以使用遥感进行测量，因此该模型可用于预测更广泛空间尺度上的藻类生产力，并确定维持水生食物网的初级生产力的重要“热点”区域。通过这种方法，我们可以为当前的保护和水资源规划框架提供信息，以在大空间尺度上管理人类发展对湿地生产力的影响。