Climate change and faunal turnover: testing the mechanics of the turnover-pulse hypothesis with South African fossil data

Paleobiology ◽  
10.1666/12043 ◽  
2013 ◽  
Vol 39 (4) ◽  
pp. 609-627 ◽  
Author(s):  
J. Tyler Faith ◽  
Anna K. Behrensmeyer
Keyword(s):  
Climate Change ◽  
Vegetation Change ◽  
Feeding Habits ◽  
Habitat Preferences ◽  
Biotic Interactions ◽  
Cape Floristic Region ◽  
Climate Oscillations ◽  
Faunal Turnover ◽  
Temporal Correlations ◽  
And Migration

The turnover-pulse hypothesis (TPH) makes explicit predictions concerning the potential responses of species to climate change, which is considered to be a major cause of faunal turnover (extinction, speciation, and migration). Previous studies have tested the TPH primarily by examining temporal correlations between turnover pulses and climatic events. It is rarely possible to dissect such correlations and observe turnover as it is occurring or to predict how different lineages will respond to climate change. Thus, whether climate change drives faunal turnover in the manner predicted by the TPH remains unclear. In this study, we test the underlying mechanics of the TPH using well-dated Quaternary ungulate records from southern Africa's Cape Floristic Region (CFR). Changes in sea level, vegetation, and topographic barriers across glacial-interglacial transitions in southern Africa caused shifts in habitat size and configuration, allowing us to generate specific predictions concerning the responses of ungulates characterized by different feeding habits and habitat preferences. Examples from the CFR show how climatically forced vegetation change and allopatry can drive turnover resulting from extinction and migration. Evidence for speciation is lacking, suggesting either that climate change does not cause speciation in these circumstances or that the evolutionary outcome of turnover is contingent on the nature and rate of climate change. Migrations and extinctions are observed in the CFR fossil record over geologically short time intervals, on the order of Milankovitch-scale climate oscillations. We propose that such climate oscillations could drive a steady and moderate level of faunal turnover over 104-year time scales, which would not be resolved in paleontological records spanning 105years and longer. A turnover pulse, which is a marked increase in turnover relative to previous and subsequent time periods, requires additional, temporally constrained climatic forcing or other processes that could accelerate evolutionary change, perhaps mediated through biotic interactions.

Fungi and plant co-variation in Arctic Siberia inferred from sedimentary ancient DNA metabarcoding during the last 45.000 years

2021 ◽  
Author(s):  
Barbara von Hippel ◽  
Kathleen R. Stoof-Leichsenring ◽  
Luise Schulte ◽  
Peter Seeber ◽  
Laura S. Epp ◽  
...  
Keyword(s):  
Climate Change ◽  
Ancient Dna ◽  
Mycorrhizal Fungi ◽  
Vegetation Change ◽  
Sediment Cores ◽  
Siberian Larch ◽  
Biotic Interactions ◽  
Arctic Ecosystems ◽  
Arctic Regions ◽  
Arctic Siberia

<p>Climate change has a great impact on boreal ecosystems including Siberian larch forests. As a consequence of warming, larch grow is possible in areas where climate used to be too cold, leading to a shift of the tree line into more arctic regions. Most plants co-exist in symbiosis with heterotrophic organisms surrounding their root system. In arctic ecosystems, mycorrhizal fungi are a prerequisite for plant establishment and survival because they support nutrient uptake from nutrient-poor soils and maintain the water supply. Until now, however, knowledge about the co-variation of vegetation and fungi is poor. Certainly, the understanding of dynamic changes in biotic interactions is important to understand adaptation mechanisms of ecosystems to climate change.</p><p>We investigated sedimentary ancient DNA from Lake Levinson Lessing, Taymyr Peninsula (Arctic Siberia, tundra), Lake Lama, Lake Kyutyunda (both northern Siberia, tundra-taiga transition zone) and Lake Bolshoe Toko (southern Siberia, forest area) covering the last about 45.000 years using ITS primers for fungi along with the chloroplast P6 loop marker for vegetation metabarcoding. We found changes in the fungal communities that are in broad agreement with vegetation turnover. To our knowledge, this is the first broad ecological study on lake sediment cores to analyze fungal biodiversity in relation to vegetation change on millennial time scales.</p>

scholarly journals A meta-analysis of the literature on climate change and migration

2021 ◽  
pp. 1-52
Author(s):  
Michel Beine ◽  
Lionel Jeusette
Keyword(s):  
Climate Change ◽  
Climatic Factors ◽  
Human Mobility ◽  
Meta Analysis ◽  
Empirical Studies ◽  
Displacement Effect ◽  
Methodological Choices ◽  
Econometric Methods ◽  
And Migration

Abstract Recent surveys of the literature on climate change and migration emphasize the important diversity of outcomes and approaches of the empirical studies. In this paper, we conduct a meta-analysis in order to investigate the role of the methodological choices of these empirical studies in finding some particular results concerning the role of climatic factors as drivers of human mobility. We code 51 papers representative of the literature in terms of methodological approaches. This results in the coding of more than 85 variables capturing the methodology of the main dimensions of the analysis at the regression level. These dimensions include authors' reputation, type of mobility, measures of mobility, type of data, context of the study, econometric methods, and last but not least measures of the climatic factors. We look at the influence of these characteristics on the probability of finding any effect of climate change, a displacement effect, an increase in immobility, and evidence in favor of a direct vs. an indirect effect. Our results highlight the role of some important methodological choices, such as the frequency of the data on mobility, the level of development, the measures of human mobility and of the climatic factors as well as the econometric methodology.

How Should We Talk About Climate Change and Migration?

2020 ◽  
Author(s):  
James Morrissey
Keyword(s):  
Climate Change ◽  
Human Migration ◽  
Policy Response ◽  
Limited Capacity ◽  
Flexible Approach ◽  
Single Term ◽  
And Migration

Abstract This paper is a response Ferris (2020), specifically to the call for coalescence around a single term by which to talk about people migrating in response to climate change. While sympathetic to the imperative behind Ferris’ (2020) call, my overall argument is to reject this proposal. Instead I argue for less of focus on what we call people migrating in response to climate change, and more of a focus on how we talk about them. To justify this, I argue that a single term is inherently reductive and likely to play upon anti-immigrant sentiment due to the need to portray ‘migration as a problem’. At best this will result in a policy focus with limited capacity to address the challenge of migration in a context of climate change. At worst it will drive a policy response that is overtly counter-productive. As an alternative, I propose embracing a multitude of discourses, informed by principals that I argue will drive a humane climate agenda, and allow for a flexible approach that can account for the variety of concerns at the nexus of climate change and human migration.

scholarly journals How can effect the synergy of climate change, soil units and vegetation groups the potential global distribution of plants up to 2300: a modelling study for prediction of potential global distribution and migration of the N<sub>2</sub> fixing species <i>Alnus</i> spp.

2015 ◽  
Vol 12 (1) ◽  
pp. 815-864
Author(s):  
A. Sakalli
Keyword(s):  
Climate Change ◽  
Nitrogen Fixation ◽  
Global Distribution ◽  
Plant Distribution ◽  
Climate Change Scenarios ◽  
Climate System Model ◽  
Current Time ◽  
Soil Units ◽  
And Migration ◽  
The Impact

Abstract. Plant migration is a well known adaptation strategy of plant groups or species with evidence from historical to present observation and monitoring studies. Importance of N2-fixing plants has increased in last decades. Alnus (alder) is an important plant group because of its nitrogen fixation ability. Alders are generally distributed in humid locations of boreal, temperate and tropical climate zones, where the nitrogen fixation is an important nitrogen source for other plants. To model the nitrogen fixation by alder, data about the global distribution of alder is absolutely required. In this study a new method and model are presented to predict the distribution of N2-fixing genus on global scale and its migration in the future by using climate change scenarios. Three linear functions were defined for the determination of climate niche of alders. The distribution and migration model (Alnus-Distribution-Model (ADM)) was improved with the aid of the soil units from FAO-Unesco Soil Database, and vegetation types from Schmithüsen's biogeographical atlas. The model was also developed to predict the impact of climate change on alder distribution by using climate data from experiments performed by the Community Climate System Model version 4 (CCSM4) including the representative concentration pathways (RCPs) mitigation scenarios, and extensions of the scenarios beyond 2100 to 2300. The model covered basic approaches to understand the combine effect of climate, soil and vegetation on plant distribution and migration in the current time and future.

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