scholarly journals Introduced herbivores restore Late Pleistocene ecological functions

2020 ◽  
Vol 117 (14) ◽  
pp. 7871-7878 ◽  
Author(s):  
Erick J. Lundgren ◽  
Daniel Ramp ◽  
John Rowan ◽  
Owen Middleton ◽  
Simon D. Schowanek ◽  
...  
Keyword(s):  
Introduced Species ◽  
Late Pleistocene ◽  
Human Impacts ◽  
Ecological Functions ◽  
Large Herbivores ◽  
Mammalian Herbivores ◽  
Introduced Herbivores ◽  
Extant Species ◽  
Herbivore Species ◽  
Trait Space

Large-bodied mammalian herbivores dominated Earth’s terrestrial ecosystems for several million years before undergoing substantial extinctions and declines during the Late Pleistocene (LP) due to prehistoric human impacts. The decline of large herbivores led to widespread ecological changes due to the loss of their ecological functions, as driven by their unique combinations of traits. However, recently, humans have significantly increased herbivore species richness through introductions in many parts of the world, potentially counteracting LP losses. Here, we assessed the extent to which introduced herbivore species restore lost—or contribute novel—functions relative to preextinction LP assemblages. We constructed multidimensional trait spaces using a trait database for all extant and extinct mammalian herbivores ≥10 kg known from the earliest LP (∼130,000 ybp) to the present day. Extinction-driven contractions of LP trait space have been offset through introductions by ∼39% globally. Analysis of trait space overlap reveals that assemblages with introduced species are overall more similar to those of the LP than native-only assemblages. This is because 64% of introduced species are more similar to extinct rather than extant species within their respective continents. Many introduced herbivores restore trait combinations that have the capacity to influence ecosystem processes, such as wildfire and shrub expansion in drylands. Although introduced species have long been a source of contention, our findings indicate that they may, in part, restore ecological functions reflective of the past several million years before widespread human-driven extinctions.

Dispersal ofAcaciaseeds by ungulates and ostriches in an African savanna

1996 ◽  
Vol 12 (3) ◽  
pp. 345-356 ◽  
Author(s):  
Maxine F. Miller
Keyword(s):  
South Africa ◽  
Seed Dispersal ◽  
Seedling Recruitment ◽  
Seedling Survival ◽  
Tree Crown ◽  
African Savanna ◽  
Large Herbivores ◽  
Mammalian Herbivores ◽  
Open Environments ◽  
Presence And Absence

ABSTRACTThe dispersal of AfricanAcaciaseeds in the presence and absence of large mammalian herbivores and ostriches was assessed in a savanna ecosystem in South Africa. In the absence of large herbivores,A. tortilisandA. niloticapods were mainly dispersed in the shade, directly beneath the tree crown and seeds remained in pods for over 18 months. In the presence of large herbivores,A. tortilis, A. niloticaandA. karrooseeds were freed from pods and were dispersed into open, non-shaded habitats. Impala dispersed mostA. tortilisseeds (18,900 ha−1), giraffe mostA. niloticaseeds (1060 ha−1) and giraffe and kudu mostA. karrooseeds (452 and 448 ha−1, respectively). Seedling survival in dung in open environments may exceed that of seedlings in soil shaded beneath the tree crown. It appears that seed dispersal by large herbivores may be advantageous to future seedling recruitment.

New Source of Dietary Data for Extinct Herbivores

1988 ◽  
Vol 30 (1) ◽  
pp. 92-97 ◽  
Author(s):  
William A. Akersten ◽  
Theresea M. Foppe ◽  
George T. Jefferson
Keyword(s):  
Late Pleistocene ◽  
Indirect Evidence ◽  
Bison Bison ◽  
Large Herbivores ◽  
Usual Assumption ◽  
Microhistological Analysis ◽  
Rancho La Brea ◽  
Very High ◽  
Control Study ◽  
Dietary Data

The teeth of many large herbivores contain “pockets” (fossettes, fossettids, etc.) which entrap impacted samples of food (dental boluses) during mastication. These do not preserve well in most fossil deposits, but at Rancho La Brea, paleobotanical remains survive essentially intact and dental boluses from late Pleistocene forms are amenable to microhistological analysis. Of the identifiable bolus contents, those from Bison antiquus averaged 87% nonmonocotyledons; from Camelops hesternus, 90% nonmonocotyledons; and from Equus occidentalis (one specimen), 56% nonmonocotyledons. A control study on modern Bison bison shows that the boluses contain somewhat lower percentages of monocotyledons than do alimentary samples from the same individuals. However, this accounts for only a part of the very high percentage of nonmonocotyledons in the boluses of the extinct Bison. We conclude that the populations of B. antiquus and C. hesternus represented at Rancho La Brea probably fed little on grasses and that there is enough indirect evidence to suggest that the same may be true for other populations of these taxa. The Equus data are not sufficient to do more than question the usual assumption that Pleistocene horses were always obligate grass eaters.

Review of feeding ecology data of Late Pleistocene mammalian herbivores from South America and discussions on niche differentiation

2015 ◽  
Vol 140 ◽  
pp. 158-165 ◽  
Author(s):  
Lucas de Melo França ◽  
Lidiane de Asevedo ◽  
Mário André Trindade Dantas ◽  
Adriana Bocchiglieri ◽  
Leonardo dos Santos Avilla ◽  
...  
Keyword(s):  
South America ◽  
Late Pleistocene ◽  
Feeding Ecology ◽  
Niche Differentiation ◽  
Mammalian Herbivores

scholarly journals Long-lasting modification of soil fungal diversity associated with the introduction of rabbits to a remote sub-Antarctic archipelago

2015 ◽  
Vol 11 (9) ◽  
pp. 20150408 ◽  
Author(s):  
Johan Pansu ◽  
Richard C. Winkworth ◽  
Françoise Hennion ◽  
Ludovic Gielly ◽  
Pierre Taberlet ◽  
...  
Keyword(s):  
Plant Communities ◽  
Fungal Diversity ◽  
Extracellular Dna ◽  
Fungal Communities ◽  
Late Nineteenth Century ◽  
Mammalian Herbivores ◽  
Introduced Herbivores ◽  
Compositional Changes ◽  
Late Nineteenth ◽  
Soil Fungal Diversity

During the late nineteenth century, Europeans introduced rabbits to many of the sub-Antarctic islands, environments that prior to this had been devoid of mammalian herbivores. The impacts of rabbits on indigenous ecosystems are well studied; notably, they cause dramatic changes in plant communities and promote soil erosion. However, the responses of fungal communities to such biotic disturbances remain unexplored. We used metabarcoding of soil extracellular DNA to assess the diversity of plant and fungal communities at sites on the sub-Antarctic Kerguelen Islands with contrasting histories of disturbance by rabbits. Our results suggest that on these islands, the simplification of plant communities and increased erosion resulting from the introduction of rabbits have driven compositional changes, including diversity reductions, in indigenous soil fungal communities. Moreover, there is no indication of recovery at sites from which rabbits were removed 20 years ago. These results imply that introduced herbivores have long-lasting and multifaceted effects on fungal biodiversity as well as highlight the low resiliency of sub-Antarctic ecosystems.

Beringia as an Ice Age genetic museum

2003 ◽  
Vol 60 (1) ◽  
pp. 94-100 ◽  
Author(s):  
Beth Shapiro ◽  
Alan Cooper
Keyword(s):  
Time Scales ◽  
Late Pleistocene ◽  
Ancient Dna ◽  
Human Impacts ◽  
Phylogenetic Analyses ◽  
Genetic Data ◽  
Ice Age ◽  
Ecological Change ◽  
Landscape Mosaics ◽  
New Perspective

AbstractThousands of Late Pleistocene remains are found in sites throughout Beringia. These specimens comprise an Ice Age genetic museum, and the DNA contained within them provide a means to observe evolutionary processes within populations over geologically significant time scales. Phylogenetic analyses can identify the taxonomic positions of extinct species and provide estimates of speciation dates. Geographic and temporal divisions apparent in the genetic data can be related to ecological change, human impacts, and possible landscape mosaics in Beringia. The application of ancient DNA techniques to traditional paleontological studies provides a new perspective to long-standing questions regarding the paleoenvironment and diversity of Late Pleistocene Beringia.

scholarly journals Varied diets, including broadleaved forage, are important for a large herbivore species inhabiting highly modified landscapes

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Annika M. Felton ◽  
Emma Holmström ◽  
Jonas Malmsten ◽  
Adam Felton ◽  
Joris P. G. M. Cromsigt ◽  
...  
Keyword(s):  
Food Availability ◽  
Diet Composition ◽  
Nutritional Composition ◽  
Large Herbivore ◽  
Large Herbivores ◽  
Winter Diet ◽  
Varied Diet ◽  
Survival And Reproduction ◽  
Herbivore Species ◽  
Free Ranging

AbstractDiet quality is an important determinant of animal survival and reproduction, and can be described as the combination of different food items ingested, and their nutritional composition. For large herbivores, human landscape modifications to vegetation can limit such diet-mixing opportunities. Here we use southern Sweden’s modified landscapes to assess winter diet mixtures (as an indicator of quality) and food availability as drivers of body mass (BM) variation in wild moose (Alces alces). We identify plant species found in the rumen of 323 moose harvested in Oct-Feb, and link variation in average calf BM among populations to diets and food availability. Our results show that variation in calf BM correlates with variation in diet composition, diversity, and food availability. A varied diet relatively rich in broadleaves was associated with higher calf BM than a less variable diet dominated by conifers. A diet high in shrubs and sugar/starch rich agricultural crops was associated with intermediate BM. The proportion of young production forest (0–15 yrs) in the landscape, an indicator of food availability, significantly accounted for variation in calf BM. Our findings emphasize the importance of not only diet composition and forage quantity, but also variability in the diets of large free-ranging herbivores.

scholarly journals Interactions between large herbivores and litter removal by termites across a rainfall gradient in a South African savanna

2011 ◽  
Vol 27 (4) ◽  
pp. 375-382 ◽  
Author(s):  
Robert Buitenwerf ◽  
Nicola Stevens ◽  
Cleo M. Gosling ◽  
T. Michael Anderson ◽  
Han Olff
Keyword(s):  
Plant Biomass ◽  
Spatial Scales ◽  
Landscape Scale ◽  
Local Scale ◽  
Arid Ecosystems ◽  
Annual Rainfall ◽  
Large Herbivores ◽  
Mammalian Herbivores ◽  
Litter Removal ◽  
Semi Arid

Abstract:Litter-feeding termites influence key aspects of the structure and functioning of semi-arid ecosystems around the world by altering nutrient and material fluxes, affecting primary production, foodweb dynamics and modifying vegetation composition. Understanding these complex effects depends on quantifying spatial heterogeneity in termite foraging activities, yet such information is scarce for semi-arid savannas. Here, the amount of litter that was removed from 800 litterbags in eight plots (100 litterbags per plot) was measured in Hluhluwe–iMfolozi Park (HiP) South Africa. These data were used to quantify variation in litter removal at two spatial scales: the local scale (within 450-m2 plots) and the landscape scale (among sites separated by 8–25 km). Subsequently, we attempted to understand the possible determinants of termites’ foraging patterns by testing various ecological correlates, such as plant biomass and bare ground at small scales and rainfall and fences that excluded large mammalian herbivores at larger scales. No strong predictors for heterogeneity in termite foraging intensity were found at the local scale. At the landscape scale termite consumption depended on an interaction between rainfall and the presence of large mammalian herbivores: litter removal by termites was greater in the presence of large herbivores at the drier sites but lower in the presence of large herbivores at the wetter sites. The effect of herbivores on termite foraging intensity may indicate a switch between termites and large herbivore facilitation and competition across a productivity gradient. In general, litter removal decreased with increasing mean annual rainfall, which is in contrast to current understanding of termite consumption across rainfall and productivity gradients. These results generate novel insights into termite ecology and interactions among consumers of vastly different body sizes across spatial scales.

scholarly journals Climate warming and humans played different roles in triggering Late Quaternary extinctions in east and west Eurasia

2017 ◽  
Vol 284 (1851) ◽  
pp. 20162438 ◽  
Author(s):  
Xinru Wan ◽  
Zhibin Zhang
Keyword(s):  
Climate Change ◽  
Late Pleistocene ◽  
Climate Warming ◽  
Human Impacts ◽  
Late Quaternary ◽  
Extinction Risk ◽  
Early Holocene ◽  
Large Mammals ◽  
Predominant Factor ◽  
Late Pleistocene To Holocene

Climate change and humans are proposed as the two key drivers of total extinction of many large mammals in the Late Pleistocene and Early Holocene, but disentangling their relative roles remains challenging owing to a lack of quantitative evaluation of human impact and climate-driven distribution changes on the extinctions of these large mammals in a continuous temporal–spatial dimension. Here, our analyses showed that temperature change had significant effects on mammoth (genus Mammuthus ), rhinoceros (Rhinocerotidae), horse (Equidae) and deer (Cervidae). Rapid global warming was the predominant factor driving the total extinction of mammoths and rhinos in frigid zones from the Late Pleistocene and Early Holocene. Humans showed significant, negative effects on extirpations of the four mammalian taxa, and were the predominant factor causing the extinction or major extirpations of rhinos and horses. Deer survived both rapid climate warming and extensive human impacts. Our study indicates that both the current rates of warming and range shifts of species are much faster than those from the Late Pleistocene to Holocene. Our results provide new insight into the extinction of Late Quaternary megafauna by demonstrating taxon-, period- and region-specific differences in extinction drivers of climate change and human disturbances, and some implications about the extinction risk of animals by recent and ongoing climate warming.

Freshwater Zooplankton Community Structure: Introduction of Large Invertebrate Predators and Large Herbivores to a Small Species Community

1988 ◽  
Vol 45 (10) ◽  
pp. 1758-1770 ◽  
Author(s):  
Michael J. Vanni
Keyword(s):  
Introduced Species ◽  
Zooplankton Community ◽  
Zooplankton Species ◽  
Small Species ◽  
Daphnia Galeata ◽  
Resident Species ◽  
Large Herbivores ◽  
Fishless Lakes ◽  
Invertebrate Predators ◽  
Daphnia Galeata Mendotae

Two hypotheses have been proposed to explain the scarcity of small zooplankton species in fishless lakes, in which large zooplankton species dominate: (1) selective predation on small species by large invertebrate predators and (2) competitive suppression of small species by large herbivores. These hypotheses were tested at the Experimental Lakes Area (ELA) by introducing a large invertebrate predator, Chaoborus americanus, and a large herbivore, Daphnia catawba, both common in fishless ELA lakes, into a zooplankton community typical of ELA lakes with fish (small zooplankton species present). Chaoborus had much more of an impact than D. catawba on resident zooplankton, although both introduced species significantly reduced the abundance of some resident species. Daphnia galeata mendotae, the dominant species in the absence of introduced species, was reduced to virtual extinction by Chaoborus. The cladocerans Bosmina and Diaphanosoma, the copepods Diaptomus spp., and the rotifer Conochilus also were reduced in abundance by Chaoborus. Daphnia galeata mendotae and Bosmina were the only resident species consistently reduced in abundance by D. catawba. These results support current conceptual models that depict invertebrate predation as an important factor responsible for the relative scarcity of small zooplankton species in fishless lakes.

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