Changes in plant collection practices from the 16 th to 21 st centuries: implications for the use of herbarium specimens in global change research

Abstract Background and aims Herbaria were recently advertised as reliable sources of information regarding historical changes in plant traits and biotic interactions. To justify the use of herbaria in global change research, we asked whether the characteristics of herbarium specimens have changed during the past centuries and whether these changes were due to shifts in plant collection practices. Methods We measured nine characteristics from 515 herbarium specimens of common European trees and large shrubs collected from 1558‒2016. We asked botanists to rank these specimens by their scientific quality, and asked artists to rank these specimens by their beauty. Key results Eight of eleven assessed characteristics of herbarium specimens changed significantly during the study period. The average number of leaves in plant specimens increased threefold, whereas the quality of specimen preparation decreased. Leaf size negatively correlated with leaf number in specimen in both among-species and within-species analyses. The proportion of herbarium sheets containing plant reproductive structures peaked in the 1850s. The scientific value of herbarium specimens increased until the 1700s, but then did not change, whereas their aesthetic value showed no systematic trends. Conclusions Our findings strongly support the hypothesis that many characteristics of herbarium specimens have changed systematically and substantially from the 16 th to 21 st centuries due to changes in plant collection and preservation practices. These changes may both create patterns which could be erroneously attributed to environmental changes and obscure historical trends in plant traits. The utmost care ought to be taken to guard against the possibility of misinterpretation of data obtained from herbarium specimens. We recommend that directional changes in characters of herbarium specimens which occurred during the past 150‒200 years, primarily in specimen’s size and in the presence of reproductive structures, are accounted for when searching for the effects of past environmental changes on plant traits.

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Using insect natural history collections to study global change impacts: challenges and opportunities

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2017.0405 ◽

2018 ◽

Vol 374 (1763) ◽

pp. 20170405 ◽

Cited By ~ 18

Author(s):

Heather M. Kharouba ◽

Jayme M. M. Lewthwaite ◽

Rob Guralnick ◽

Jeremy T. Kerr ◽

Mark Vellend

Keyword(s):

Natural History ◽

Global Change ◽

Global Changes ◽

Genomic Information ◽

Theme Issue ◽

The Past ◽

Natural History Collections ◽

Global Change Research ◽

Challenges And Opportunities

Over the past two decades, natural history collections (NHCs) have played an increasingly prominent role in global change research, but they have still greater potential, especially for the most diverse group of animals on Earth: insects. Here, we review the role of NHCs in advancing our understanding of the ecological and evolutionary responses of insects to recent global changes. Insect NHCs have helped document changes in insects' geographical distributions, phenology, phenotypic and genotypic traits over time periods up to a century. Recent work demonstrates the enormous potential of NHCs data for examining insect responses at multiple temporal, spatial and phylogenetic scales. Moving forward, insect NHCs offer unique opportunities to examine the morphological, chemical and genomic information in each specimen, thus advancing our understanding of the processes underlying species’ ecological and evolutionary responses to rapid, widespread global changes. This article is part of the theme issue ‘Biological collections for understanding biodiversity in the anthropocene’.

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Using herbaria to study global environmental change

10.7287/peerj.preprints.26886v1 ◽

2018 ◽

Author(s):

Patricia L M Lang ◽

Franziska M Willems ◽

J F Scheepens ◽

Hernán A Burbano ◽

Oliver Bossdorf

Keyword(s):

Global Change ◽

Environmental Change ◽

Global Environmental Change ◽

Herbarium Specimens ◽

Long Term Effects ◽

Temporal Dimension ◽

Global Environmental ◽

Evolutionary Changes ◽

Global Change Research

During the last centuries, humans have transformed global ecosystems. With their temporal dimension, herbaria provide the otherwise scarce long-term data crucial to track ecological and evolutionary changes over these centuries of global change. The sheer size of herbaria, together with their increasing digitization and the possibility of sequencing DNA from the preserved plant material, makes them invaluable resources to understand ecological and evolutionary species responses to global environmental change. Following the chronology of global change, we highlight how herbaria can inform about long-term effects on plants of at least four of the main drivers of global change: pollution, habitat change, climate change, and invasive species. We summarize how herbarium specimens so far have been used in global change research, discuss future opportunities and challenges posed by the nature of these data, and advocate for an intensified use of these 'windows into the past' for global change research and beyond.

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