Data from: High-productivity vegetation is important for lessening bird declines during prolonged drought

1.Locations in which ecological assemblages show high resistance to climate pressures, such as drought, are likely to be important refuges for biota in changing climates. We asked whether environmental characteristics of locations were associated with the capacity of bird assemblages to withstand prolonged drought.

2.We used a multi-species index to quantify trends in bird assemblages during a 13-year drought at >500 locations (>18,000 surveys) in the Murray-Darling Basin, south eastern Australia, using data from the Atlas of Australian Birds. We investigated whether the resistance of bird assemblages was associated with: (1) vegetation structure; (2) vegetation productivity (vegetation greenness); (3) landscape context (patch size, landscape vegetation cover); or (4) physical environment (elevation, terrain, topography, availability of surface water).

3.Vegetation productivity, measured by vegetation greenness (Normalized Difference Vegetation Index), was the only potential predictor with strong evidence of an effect, and was positively associated with the index of drought resistance. There was little evidence that variables characterising landscape context, vegetation structure or the physical environment of sites were associated with drought resistance of bird communities.

4.Synthesis and applications. Bird assemblages in locations with high vegetation greenness are more resistant to severe drought. Prioritizing conservation investments in areas with locally high vegetation productivity is likely to be an effective strategy for increasing the resistance of bird assemblages to extreme drought, especially in areas where mean productivity is relatively low, such as arid and semi-arid regions. Remotely sensed vegetation greenness may be a promising source of information for identifying drought refuges for birds and possibly other biota.

1. 生态群落对干旱等气候压力具备高抵抗力的区域，很可能成为气候变化背景下生物群落的重要避难所。本研究旨在探究区域环境特征与鸟类群落抵御长期干旱的能力之间是否存在关联。
2. 本研究依托澳大利亚鸟类图鉴（Atlas of Australian Birds）的观测数据，针对澳大利亚东南部墨累-达令盆地（Murray-Darling Basin）内500余个调查点位（累计超过18000次野外调查），采用多物种种群指数量化了13年干旱期间鸟类群落的动态变化。本研究探究了鸟类群落的抗旱能力与以下四类因素的关联：(1) 植被结构；(2) 植被生产力（植被绿度）；(3) 景观背景（斑块面积、景观植被覆盖率）；(4) 物理环境（海拔、地形、地貌、地表水可获得性）。
3. 以植被绿度（归一化差异植被指数，Normalized Difference Vegetation Index）为量化指标的植被生产力，是唯一被证实具备显著影响的潜在预测因子，且与鸟类群落抗旱指数呈正相关。现有研究证据极少支持景观背景、植被结构或调查点位物理环境相关变量与鸟类群落抗旱能力存在关联。
4. 研究总结与应用启示：植被绿度较高区域的鸟类群落，对严重干旱的抵抗力更强。将保护资源优先投向本地植被生产力较高的区域，或可有效提升鸟类群落对抗极端干旱的能力，这一策略在干旱、半干旱等平均植被生产力偏低的区域尤为适用。遥感获取的植被绿度数据，或可成为识别鸟类乃至其他生物群落干旱避难所的可靠信息来源。