Data from Beyond MAP: A guide to dimensions of rainfall variability for tropical ecology

AbstractTropical ecologists have long recognized rainfall as the key climate filter shaping tropical ecosystem structure and function across space and time. Still, tropical ecologists have historically had a limited toolkit for characterizing rainfall, largely relying on simple metrics like mean annual precipitation (MAP) and dry season length to characterize rainfall regimes that vary along many more dimensions. Here, we review methods for quantifying dimensions of rainfall variability on multiple time scales, with a focus on ecological applications of these methods. We also discuss key considerations for tropical ecologists looking to use rainfall metrics that better align with hypothesized biological or ecological mechanisms or that more effectively describe rainfall variability in the systems we study, and provide a toolkit (R scripts and gridded datasets) to do so. We argue that incorporating more sophisticated approaches to quantify rainfall variability into study design and statistical analyses will enhance our understanding of past, ongoing, and future changes in tropical ecosystems.  , MethodsDataset contains four gridded datasets of dimensions of rainfall variation as described in Schwartz et al. All variables were derived from monthly rainfall time series, derived from TRMM data from 1997-2016 and are presented at 0.25 degree resolution. Each .tif file has two bands. Band 1 is the mean value for the DRV and band 2 is its standard deviation over the 20-year time period.  Also included are R functions and example scripts for calculating DRVs. , Usage notesNecessary information is in the readme files.

摘要：热带生态学家长期以来已明确，降雨是塑造热带生态系统时空结构与功能的关键气候过滤因子。但长期以来，热带生态学家用于表征降雨的可用工具十分有限，大多仅依赖年平均降水量（mean annual precipitation，MAP）、旱季时长等简单指标，来描述维度繁多的降雨格局。本研究综述了多时间尺度下降雨变异性维度的量化方法，并重点探讨了这些方法的生态学应用。此外，本文还针对热带生态学家探讨了关键考量要点：他们希望采用更贴合假设的生物学或生态学机制、或能更有效地描述所研究系统中降雨变异性的降雨指标，并提供了可实现该目标的工具包（R脚本与格点数据集）。我们认为，将更精密的降雨变异性量化方法融入研究设计与统计分析，将有助于深化我们对热带生态系统过去、当前及未来变化的认知。, 方法：本数据集包含Schwartz等人所述的4套降雨变异性维度格点数据集。所有变量均源自1997-2016年热带降雨测量任务（Tropical Rainfall Measuring Mission，TRMM）数据生成的月降雨时间序列，数据分辨率为0.25度。每个.tif文件包含两个波段：波段1为20年研究期内DRV的平均值，波段2为其标准差。此外还包含用于计算DRV的R函数与示例脚本。, 使用说明：相关必要信息详见自述文件（readme files）。