Abstract Detail

Paleobotany

Quirk, Zack [1], Smith, Selena [2], Acosta, R. Paul [3].

Where did they come from, where did they go: examining niche conservatism through time in a primarily tropical plant lineage.

Many plant and animal species will be greatly affected by anthropogenic climate change in the coming years, which raises the question of whether climatic niches of species change. Fossils can provide insight on how organisms were affected by climatic change through larger timescales. While the fossil record has been used to test for niche conservatism (organismal preservation of original ecological traits over time) in fossil invertebrates to determine how the environmental constraints for these organisms have changed through time compared to the modern, niche conservatism is largely unexplored in plants, despite being invaluable to terrestrial ecosystems and global agriculture. In this study, we aim to test if climatic niche constraints have remained consistent through time by characterizing climate niches of living ginger plants (Zingiberaceae) and comparing them with the paleo-niches reconstructed based on fossil distribution. Gingers are primarily found in the tropics today, but have they inhabited tropical climates since their origin in the Cretaceous? If ginger niches have remained conserved through time, then we can use extant ginger climate regimes for reconstructing past climates. To test this, we used ArcGIS Pro to calculate the modern climate niches of Zingiberaceae and its four subfamilies from living occurrence data and bioclimatic variable data, namely cold month mean temperature (CMMT), mean annual temperature (MAT), and mean annual precipitation (MAP). Fossil ginger occurrences were collected from the literature, with the distribution mapped using GPlates and PALEOMAP. Based on cold month mean temperature (CMMT) and mean annual temperature (MAT), only one subfamily is deemed as tropical (CMMT > 18^oC) while the rest are subtropical (CMMT < 18^oC, but MAT is > 16^oC). The fossil ginger distribution shows a Cretaceous presence in both higher latitudes and the tropics, but then remains only in those upper latitudes for the rest of the Cenozoic fossil record. With impending paleoclimate modeling data, we expect to confirm that the climatic conditions for these upper latitude fossil gingers was similar to those of the modern day, as much of the Cenozoic had expanded (sub)tropical climates. If this assertion is correct, then we can use fossil ginger occurrences for reconstructing past climates. Fossil gingers today are taxonomically placed in either Zingiberaceae or the subfamily Alpinioideae, but we recommend to only use Alpinioideae-linked fossils because species of this group better represent a subtropical climate regime, since some living species within the other subfamilies of Zingiberaceae can persist in below freezing conditions.

1 - University Of Michigan Ann Arbor, Earth And Environmental Science, 2534 CC Little Bldg, Michigan, MI, 48103, United States
2 - Department Of Earth & Environmental Sciences, 1100 North University Avenue, Room 2534, NUB, Ann Arbor, MI, 48109, United States
3 - University of Michigan Ann Arbor, Earth & Environmental Sciences, 1100 North University Avenue, Ann Arbor, MI, 48109, United States

Keywords:
Paleobotany
gingers
Zingiberaceae
climate niche
niche conservatism.

Presentation Type: Oral Paper
Session: PL2, Paleobotany: Cookson Student Presentations - Session II
Location: /
Date: Monday, July 19th, 2021
Time: 1:15 PM(EDT)
Number: PL2004
Abstract ID:300
Candidate for Awards:Isabel Cookson Award