Data from: Relationships between spatial metrics and plant diversity in constructed freshwater wetlands

The diversity of plant species and their distribution in space are both thought to have important effects on the function of wetland ecosystems. However, knowledge of the relationships between plant species and spatial diversity remains incomplete. In this study, we investigated relationships between spatial pattern and plant species diversity over a five year period following the initial restoration of experimental wetland ecosystems. In 2003, six identical and hydrologically-isolated 0.18 ha wetland “cells” were constructed in former farmland in northeast Ohio. The systems were subjected to planting treatments that resulted in different levels of vascular plant species diversity among cells. Plant species diversity was assessed through annual inventories. Plant spatial pattern was assessed by digitizing low-altitude aerial photographs taken at the same time as the inventories. Diversity metrics derived from the inventories were significantly related to certain spatial metrics derived from the photographs, including cover type diversity and contagion. We found that wetlands with high cover type diversity harbor higher plant species diversity than wetlands with fewer types of patches. We also found significant relationships between plant species diversity and spatial patterning of patch types, but the direction of the effect differed depending on the diversity metric used. Links between diversity and spatial pattern observed in this study suggest that high-resolution aerial imagery may provide wetland scientists with a useful tool for assessing plant diversity.

植物物种多样性及其空间分布，均被认为对湿地生态系统的功能具有重要影响。然而，目前学界对植物物种与空间多样性之间的关联认知仍不全面。本研究针对实验湿地生态系统初始修复后的五年周期，探究了空间格局与植物物种多样性之间的关联。2003年，研究团队在俄亥俄州东北部的弃耕地中，构建了6个规格统一、水文隔离的0.18公顷湿地单元（wetland cell）。各单元通过差异化的种植处理，形成了各异的维管植物（vascular plant）物种多样性水平。研究通过年度清查对植物物种多样性进行评估，并通过对与清查同期拍摄的低海拔航空照片进行数字化处理，评估植物空间格局。由清查得到的多样性指标，与从照片提取的部分空间指标（包括覆被类型多样性与聚集度（contagion））显著相关。研究发现，覆被类型多样性较高的湿地，其植物物种多样性显著高于斑块类型更少的湿地。本研究同时发现，植物物种多样性与斑块类型的空间格局之间存在显著关联，但关联的方向因所采用的多样性指标而异。本研究中观测到的多样性与空间格局之间的关联表明，高分辨率航空影像可为湿地生态研究者提供一种评估植物物种多样性的有效工具。