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Ecosystem function relies in part on aligned relationships between functional traits of animals and the environments in which they live. Studies of trait-environment relationships have largely focused on communities of native species, but domestic and non-native species also play a role in the functioning of modern ecosystems. We use ecometrics, or study of functional trait-environment relationships, to evaluate the impact of domestic and non-native species on community-level trait composition and its relationship with precipitation by comparing four community compositions: modern native, modern native plus domestic, modern native plus non-native, and late Pleistocene (0.126–0.0117 Ma). We integrate large and small herbivorous mammals into a single ecometric model of hypsodonty (i.e., tooth crown height) and annual precipitation (n=8439, r=-0.7, R2=0.4, p<0.001). We hypothesize: 1) ecometric models of modern native communities will differ from those for late Pleistocene communities, 2) inclusion of domestic species will align ecometric relationships with those from the late Pleistocene, 3) inclusion of non-native species will maintain ecometric relationships of modern native communities. We found modern communities of native species have lower hypsodonty values and higher precipitation estimates than late Pleistocene communities. Domestic species shift modern communities toward higher hypsodonty values and lower precipitation estimates like those in the late Pleistocene. Today’s domestics are mostly high-crowned grazing species representative of the fauna lost prior to the Holocene. Non-native species do not shift modern native trait composition or the associated precipitation estimates, illustrating the success of non-native species due to trait alignment with their new environments. Thus, conservation and restoration efforts should consider trait composition of whole communities because it provides unique information to measures of taxonomic composition.
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Ecometric models of small mammal hypsodonty can estimate paleoprecipitation across eastern Africa
Ecometric analyses use the relationships between functional traits and the environment at the community level to quantitatively estimate past climatic and environmental variables at fossil sites. Hypsodonty (tooth crown height) in North American rodent and lagomorph (Glires) communities is correlated with mean annual temperature and annual precipitation. Here, we examine the community hypsodonty of African Glires to test if this relationship translates to a continent with more extreme climates and to quantify paleoprecipitation at important fossil sites. Categorical hypsodonty values were gathered from the literature and museum collections for 94 modern African taxa (88%). We used maximum likelihood to model the ecometric relationship between hypsodonty and annual precipitation. We then produced trait-based estimates of paleoprecipitation for 26 well sampled fossil localities from eastern Africa over the last 5.7 Ma. We confirmed other regional studies by identifying increasing aridity and decreasing annual precipitation (824 mm to 480 mm) in the Late Miocene of Kenya. From the Ethiopian Shungura Formation, we estimated temporal fluctuations in precipitation that correspond with the presence or absence of paleolakes and rivers. Small mammal community hypsodonty illustrates that east African communities have converged towards mesodont means and high standard deviations in response to climate change.
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- PAR ID:
- 10534181
- Publisher / Repository:
- Palaeogeography, Palaeoclimatology, Palaeoecology
- Date Published:
- Journal Name:
- Palaeogeography, Palaeoclimatology, Palaeoecology
- Volume:
- 643
- Issue:
- C
- ISSN:
- 0031-0182
- Page Range / eLocation ID:
- 112181
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1016/j.palaeo.2024.112181
