Data from: Modern pollen assemblages of the Neotropics

Aim: To provide a database of modern pollen abundances from a diversity of
Neotropical locations. Location: The Neotropics, especially western
Amazonia, the Andes, The Galápagos, Central America, Puerto Rico, and
Mexico. Methods: Over a 30-year period, mud-water interface samples, moss
polsters, soils, and pollen traps were used to assay modern pollen rain.
Standard extraction methods were used and a minimum of 300 terrestrial
pollen grains counted and identified per sample. Bioclimatic data were
assigned to each location, and sexual traits and pollination syndromes are
provided for some genera. A detrended correspondence analysis (DCA) shows
the structuring of the data relative to mean annual temperatures (MAT),
mean annual precipitation (MAP), and precipitation of the driest quarter
(PDQ). Probability density functions of distances among samples are
calculated within and between Holdridge Life Zones, based on sample DCA
scores. Results: The modern pollen of 636 locations are documented, with
>500 pollen types identified. The dataset spans settings with MAT
< 5oC to >25oC, and with MAP ranging from c. 500-5000 mm,
and PDQ from 80 - 1500 mm. Ordination of the dataset provides evidence
that assemblages differ according to temperature and precipitation,
although historical biogeography also shapes pollen rains. The pollen
grains of zoophilous species contribute important information to habitat
descriptions, but they are under-represented in the dataset. Main
conclusions: The dataset covers a broad environmental range and can help
inform biogeographic and paleoenvironmental interpretation of
paleoecological records. Some caution in using the data is needed as the
field of tropical palynology is maturing and the data gathered 30 years
ago are less detailed than those gathered recently. Although anemophilous
taxa tend to be over-represented in neotropical pollen spectra, the
majority of pollen identified in each sample are from zoophilous species.

研究目标：构建涵盖多样新热带区域的现代花粉丰度数据库。
研究区域：新热带区，尤其以西亚马逊、安第斯山脉、加拉帕戈斯群岛、中美洲、波多黎各及墨西哥为主。
研究方法：在长达30年的研究周期中，通过采集泥水界面样品、苔藓垫、土壤样品及花粉捕捉器获取现代花粉雨数据。采用标准孢粉提取流程，每份样品至少计数并鉴定300粒陆生花粉粒。为每个采样点匹配对应生物气候数据，并为部分属级类群提供繁殖性状与传粉综合征信息。通过除趋势对应分析（Detrended Correspondence Analysis, DCA），可展示数据沿年平均气温（Mean Annual Temperatures, MAT）、年平均降水量（Mean Annual Precipitation, MAP）及最干季降水量（Precipitation of the Driest Quarter, PDQ）的分布格局。基于各采样点的DCA得分，计算霍尔德里奇生命带（Holdridge Life Zones）内部及不同生命带间的样本距离概率密度函数。
研究结果：本数据库共记录636个采样点的现代花粉信息，已鉴定花粉类型超500种。数据集覆盖的环境梯度范围包括年平均气温低于5℃至高于25℃，年平均降水量约500~5000 mm，最干季降水量80~1500 mm。对数据集进行排序分析后发现，花粉组合的分异主要受温度与降水量调控，但历史生物地理学过程同样会塑造现代花粉雨的组成。虫媒植物的花粉可为生境描述提供重要信息，但本数据集内此类花粉占比偏低。
主要结论：本数据集覆盖了广泛的环境梯度，可为生物地理学及古生态记录的古环境解释提供参考。由于热带孢粉学仍处于发展完善阶段，且30年前采集的数据细节程度不及近期采集的数据，因此使用本数据集时需谨慎。尽管风媒类群在新热带区花粉谱中往往占比偏高，但每份样品中鉴定出的多数花粉仍来自虫媒植物。