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Pleystocene Parks & Rewilding
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  *This image is copyright of its original author  *This image is copyright of its original author MAMMOTH STEPPE During the Last Glacial Maximum, the mammoth steppe was the Earth’s most extensive biome. It spanned from Spain eastwards across Eurasia to Canada and from the arctic islands southwards to China. It had a cold, dry climate; the vegetation was dominated by palatable high-productivity grasses, herbs and willow shrubs, and the animal biomass was dominated by the bison, horse, and the woolly mammoth. This ecosystem covered wide areas of the northern part of the globe, thrived for approximately 100,000 years without major changes, and then suddenly became all but extinct about 12,000 years ago. During glacial periods, there is clear evidence for intense aridity due to water being held in glaciers and their associated effects on climate.The mammoth steppe was like a huge 'inner court' that was surrounded on all sides by moisture-blocking features: massive continental glaciers, high mountains, and frozen seas. These kept rainfall low and created more days with clear skies than are seen today, which increased evaporation in the summer leading to aridity, and radiation of warmth from the ground into the black night sky in the winter leading to cold. This is thought to have been caused by seven factors: -The driving force for the core Asian steppe was an enormous and stable high-pressure system north of the Tibetan Plateau. -Deflection of the larger portion of the Gulf Stream southward, past southern Spain onto the coast of Africa, reduced temperatures (hence moisture and cloud cover) that the North Atlantic Current brings to Western Europe.  *This image is copyright of its original author  *This image is copyright of its original author -Growth of the Scandinavian ice sheet created a barrier to North Atlantic moisture. -Icing over of the North Atlantic sea surface with reduced flow of moisture from the east. -The winter (January) storm track seems to have swept across Eurasia on this axis. -Lowered sea levels exposed a large continental shelf to the north and east producing a vast northern plain which increased the size of the continent to the north. -North American glaciers shielded interior Alaska and the Yukon Territory from moisture flow. These physical barriers to moisture flow created a vast arid basin or protected 'inner court' spanning parts of three continents.  *This image is copyright of its original author Animal biomass and plant productivity of the mammoth steppe were similar to today's African savannah. There is no comparison to it today. The mammoth steppe was dominated in biomass by bison, horse, and the woolly mammoth, and was the center for the evolution of the Pleistocene woolly fauna. On Wrangel Island, the remains of woolly mammoth, woolly rhinoceros, horse, bison and musk ox have been found. Reindeer and small animal remains do not preserve, but reindeer excrement has been found in sediment. In the most arid regions of the mammoth steppe that were to the south of Central Siberia and Mongolia, woolly rhinoceros were common but woolly mammoths were rare.Reindeer live in the far north of Mongolia today and historically their southern boundary passed through Germany and along the steppes of eastern Europe, indicating they once covered much of the mammoth steppe. Mammoths survived on the Taimyr Peninsula until the Holocene. A small population of mammoth survived on St. Paul Island, Alaska, up until 3750 BC, and the small mammoths of Wrangel Island survived until 1650 BC. Bison in Alaska and the Yukon, and horses and muskox in northern Siberia, have survived the loss of the mammoth steppe.One study has proposed that a change of suitable climate caused a significant drop in the mammoth population size, which made them vulnerable to hunting from expanding human populations. The coincidence of both of these impacts in the Holocene most likely set the place and time for the extinction of the woolly mammoth The mammoth steppe had a cold, dry climate. During the past interglacial warmings, forests of trees and shrubs expanded northwards into the mammoth steppe, when northern Siberia, Alaska and the Yukon (Beringia) would have formed a mammoth steppe refugium. When the planet grew colder again, the mammoth steppe expanded. This ecosystem covered wide areas of the northern part of the globe, thrived for approximately 100,000 years without major changes, and then suddenly became extinct about 12,000 years ago.  *This image is copyright of its original author
New paper here
Pleistocene Arctic megafaunal ecological engineering as a natural climate solution? Abstract: Natural climate solutions (NCS) in the Arctic hold the potential to be implemented at a scale able to substantially affect the global climate. The strong feedbacks between carbon-rich permafrost, climate and herbivory suggest an NCS consisting of reverting the current wet/moist moss and shrub-dominated tundra and the sparse forest–tundra ecotone to grassland through a guild of large herbivores. Grassland-dominated systems might delay permafrost thaw and reduce carbon emissions—especially in Yedoma regions, while increasing carbon capture through increased productivity and grass and forb deep root systems. Here we review the environmental context of megafaunal ecological engineering in the Arctic; explore the mechanisms through which it can help mitigate climate change; and estimate its potential—based on bison and horse, with the aim of evaluating the feasibility of generating an ecosystem shift that is economically viable in terms of carbon benefits and of sufficient scale to play a significant role in global climate change mitigation. Assuming a megafaunal-driven ecosystem shift we find support for a megafauna-based arctic NCS yielding substantial income in carbon markets. However, scaling up such projects to have a significant effect on the global climate is challenging given the large number of animals required over a short period of time. A first-cut business plan is presented based on practical information—costs and infrastructure—from Pleistocene Park (northeastern Yakutia, Russia). A 10 yr experimental phase incorporating three separate introductions of herds of approximately 1000 individuals each is costed at US$114 million, with potential returns of approximately 0.3–0.4% yr−1 towards the end of the period, and greater than 1% yr−1 after it. Institutional friction and the potential role of new technologies in the reintroductions are discussed.
Pleistocene rewilding is the advocacy of the reintroduction of descendants of Pleistocene megafauna, or their close ecological equivalents. An extension of the conservation practice of rewilding, which involves reintroducing species to areas where they became extinct in recent history (hundreds of years ago or less).
So what are our thoughts on this idea? Is it a good way for ecological restoration, or has it been too long since certain creatures traversed certain areas for their proxies to simply be put back in? Interested in hearing everyone's opinions on this. Here's a paper on it: Pleistocene Rewilding: An Optimistic Agenda for Twenty-First Century Conservation Abstract: Large vertebrates are strong interactors in food webs, yet they were lost from most ecosystems after the dispersal of modern humans from Africa and Eurasia. We call for restoration of missing ecological functions and evolutionary potential of lost North American megafauna using extant conspecifics and related taxa. We refer to this restoration as Pleistocene rewilding; it is conceived as carefully managed ecosystem manipulations whereby costs and benefits are objectively addressed on a case-by-case and locality-by-localitybasis. Pleistocene rewilding would deliberately promote large, long-lived species over pest and weed assemblages, facilitate the persistenceand ecological effectiveness of megafauna on a global scale, and broaden the underlying premise of conservation from managing extinction to encompass restoring ecological and evolutionary processes. Pleistocene rewilding can begin immediately with species such as Bolson tortoises and feral horses and continue through the coming decades with elephants and Holarctic lions. Our exemplar taxa would contribute biological, economic, and cultural benefits to North America. Owners of large tracts of private land in the central and western United States could be the first to implement this restoration. Risks of Pleistocene rewilding include the possibility of altered disease ecology and associated human health implications, as well as unexpected ecological and sociopolitical consequences of reintroductions. Establishment of programs to monitor suites of species interactions and their consequences for biodiversity and ecosystem health will be a significant challenge. Secure fencing would be a major economic cost, and social challenges will include acceptance of predation as anoverriding natural process and the incorporation of pre-Columbian ecological frameworks into conservation strategies. https://biology.unm.edu/fasmith/Web_Page...%20Nat.pdf
A Geographic Assessment of the Global Scope for Rewilding with Wild-Living Horses (Equus ferus)
Abstract Megafaunas worldwide have been decimated during the late Quaternary. Many extirpated species were keystone species, and their loss likely has had large effects on ecosystems. Therefore, it is increasingly considered how megafaunas can be restored. The horse (Equus ferus) is highly relevant in this context as it was once extremely widespread and, despite severe range contraction, survives in the form of domestic, feral, and originally wild horses. Further, it is a functionally important species, notably due to its ability to graze coarse, abrasive grasses. Here, we used species distribution modelling to link locations of wild-living E. ferus populations to climate to estimate climatically suitable areas for wild-living E. ferus. These models were combined with habitat information and past and present distributions of equid species to identify areas suitable for rewilding with E. ferus. Mean temperature in the coldest quarter, precipitation in the coldest quarter, and precipitation in the driest quarter emerged as the best climatic predictors. The distribution models estimated the climate to be suitable in large parts of the Americas, Eurasia, Africa, and Australia and, combined with habitat mapping, revealed large areas to be suitable for rewilding with horses within its former range, including up to 1.5 million ha within five major rewilding areas in Europe. The widespread occurrence of suitable climates and habitats within E. ferus’ former range together with its important functions cause it to be a key candidate for rewilding in large parts of the world. Successful re-establishment of wild-living horse populations will require handling the complexity of human–horse relations, for example, potential conflicts with ranchers and other agriculturalists or with other conservation aims, perception as a non-native invasive species in some regions, and coverage by legislation for domestic animals. 
Do you think the cave bear would help the snow from thawing in the Pleistocene park and around that area ? The owner of the land said he needed large herbivores since the mammoth is extinct so maybe a large mostly herbivorous bear could help.
Megafauna extinctions have reduced biotic connectivity worldwide
Abstract Aim Connectivity among ecosystems is necessary to sustain ecological processes that promote biodiversity, community stability and ecosystem resilience, such as organism and nutrient dispersal. Along with human land use and habitat fragmentation, connectivity can also be affected by faunal changes. Here, we address this issue by studying how human‐driven late Quaternary extinctions and extirpations of terrestrial mammals have affected the movement capacity of assemblages, an estimate of the potential connectivity among ecosystems promoted by wildlife. Location Global. Time period Late Pleistocene to the Anthropocene. Major taxa studied All 4,395 (4,073 extant and 322 extinct) terrestrial mammals alive in the Late Pleistocene. Methods We combined macroecological estimates of home range size with range maps of current and natural geographical distributions of species to investigate how human pressure has modified natural movement capacity of terrestrial assemblages and how movement capacity will respond to future extinction and rewilding scenarios. Results Our results showed that 74% of average and 83% of maximum movement capacity of Late Pleistocene mammal assemblages has been lost owing to prehistorical and historical extinctions and extirpations. We also found that movement capacity will decrease further if current extinction trajectories are not averted. However, our results showed that current average and maximum movement capacity can be restored to twice their current values under a full rewilding scenario and that average, but not maximum movement capacity, will increase under a conservative rewilding scenario, that is, without restoring the largest megafauna most likely to cause major human–wildlife conflicts. Main conclusions Prehistorical and historical losses of megafauna have caused severe decreases in movement capacity of mammal assemblages, hence large reductions in ecosystem connectivity. Reintroductions can partly restore biotic connectivity, especially when the largest megafauna are also restored. However, natural levels of movement capacity cannot be recovered fully without including ecological replacements for extinct species in rewilding efforts.
Introduced herbivores restore Late Pleistocene ecological functions
Abstract 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.
A figure from the study above
 *This image is copyright of its original author Fig. 3. Select introduced herbivores and their extinct nearest neighbors in those continents most impacted by extinctions and introductions. The color of the top bar indicates the number of extant species (per body mass bin and climate zone) that are more similar to the nearest neighbor than the introduced species is, while the lower bar color indicates dietary guild. For a full list of pairs see the SI Appendix, Fig. S3.
Macroecological perspectives on the functional impacts of late-Quaternary megafauna extinctions and potential restoration through trophic rewilding
Abstract: [b]Background/Question/Methods: During the last 100,000 years, approximately 50% of terrestrial mammal species with body mass ≥10 kg (megafauna s.l.) have been in lost in a selective extinction event increasingly strongly linked to the global expansion of Homo sapiens. Hereby, current mammal assemblages in much of the world are megafauna-poor and deviate from the norm across the mid to late Cenozoic. There are likely strong functional consequences, but these are poorly understood, as are their consequences for restoration efforts. We address these questions through a macroecological approach, with a focus on large herbivores given their importance for ecosystem structure and functioning in many areas and their strong, but controversial role in conservation and restoration efforts. To this end, we compiled a new global dataset containing habitat, body mass and diet information on all late-Quaternary mammal herbivore species ≥10 kg that existed during the last 130,000 years, using it to 1) compare the functional composition of current herbivore assemblages with that of no-extinction assemblages, and 2) assess the extent to which reestablishment of extirpated herbivores via trophic rewilding efforts have potential to restore ecosystem functioning (assessing the impact of varying restoration baselines: historical (1500 AD), prehistorical Holocene, Late Pleistocene). Results/Conclusions: We find that roughly 41% of terrestrial ecosystems contain herbivore assemblages that are functionally non-analogous to their no-extinction counterparts. They lack major functional types (generally down-sized and with greater dominance by browsers), and their functional composition is regionally more heterogeneous, suggesting the late-Quaternary extinctions have fundamentally altered the functional composition of herbivore assemblages worldwide. Furthermore, they imply that many parts currently experience herbivory regimes to which the local biota are not evolutionarily adapted. We furthermore find these functional losses could be partially restored by re-establishing extant species within their native ranges, especially for the deeper baselines, but only partially so due to global extinctions (e.g., still strongly reduced assemblage median and maximum body mass). These findings show that without using non-native species as functional replacements or so far unfeasible deextinction, restoration can only achieve partial recovery of herbivore assemblages. Real-world implementation of trophic rewilding furthermore needs to tackle complexities such carnivores, societal acceptability, habitat availability and ongoing climate changes. Nevertheless, we suggest that a fuller consideration of the potential for restoring herbivores towards their pre-extinction typical functional composition would promote self-regulating, biodiverse ecosystems for the large areas needed to overcome the ongoing biodiversity crisis.[/b]
Reintroducing extirpated herbivores could partially reverse the late Quaternary decline of large and grazing species
Abstract: Aim Reinstating large, native herbivores is an essential component of ecological restoration efforts, as these taxa can be important drivers of ecological processes. However, many herbivore species have gone globally or regionally extinct during the last 50,000 years, leaving simplified herbivore assemblages and trophically downgraded ecosystems. Here, we discuss to what extent trophic rewilding can undo these changes by reinstating native herbivores. Location Global. Time period We report functional trait changes from the Late Pleistocene to the present, and estimated trait changes under future scenarios. Major taxa studied Wild, large (≥ 10 kg), terrestrial, mammalian herbivores. Methods We use a functional trait dataset containing all late Quaternary large herbivores ≥ 10 kg to look at changes in the body mass and diet composition of herbivore assemblages, a proxy for species’ ecological effects. First, we assess how these traits have changed from the Late Pleistocene to the present. Next, we quantify how the current body mass and diet composition would change if all extant, wild herbivores were restored to their native ranges (and if no functional replacements were used), exploring scenarios with different baselines. Results Defaunation has primarily removed large and grazing herbivores. Reinstating extant herbivores across their native ranges would reverse these changes, especially when reinstating them to their prehistoric distributions. It would partially restore herbivore body mass and diet composition to pre‐anthropogenic conditions. However, in the absence of complementary interventions (e.g., introducing functional replacements), many herbivore assemblages would remain down‐sized and browser dominated, relative to pre‐anthropogenic conditions. Main conclusions Many terrestrial herbivore assemblages—and hence ecosystems—would remain trophically downgraded, even after bringing back all extant, native herbivores. Therefore, complementary interventions would be required to achieve complete functional restoration. Nevertheless, our findings suggest that reintroducing the remaining native herbivores would diversify the herbivory and disturbances of herbivore assemblages.
Figures from the study above
 *This image is copyright of its original author Body mass and dietary structure of herbivore assemblages. (a) Median assemblage body mass of current herbivore assemblages; (b) median assemblage body mass of present‐natural herbivore assemblages; © dietary composition of current herbivore assemblages; (d) dietary composition of present‐natural herbivore assemblages; (e–g) median assemblage body mass following restoration without functional replacements, using a 1500s, Holocene or Pleistocene baseline; (h–j) dietary composition of herbivore assemblages following restoration without functional replacements, using a 1500s, Holocene or Pleistocene baseline  *This image is copyright of its original author Changes in the body mass and dietary structure of herbivore assemblages following rewilding without functional replacements. (a–c) Changes in median assemblage body mass following restoration when using a 1500s, Holocene or Pleistocene baseline. (d–f) Dietary changes following restoration with herbivores when using a 1500s, Holocene or Pleistocene baseline
Based on this it seems Pleistocene park is still very far away from achieving its goal of reviving the mammoth steppe
Effects of large herbivore grazing on relics of the presumed mammoth steppe in the extreme climate of NE-Siberia Abstract The Siberian mammoth steppe ecosystem changed dramatically with the disappearance of large grazers in the Holocene. The concept of Pleistocene rewilding is based on the idea that large herbivore grazing significantly alters plant communities and can be employed to recreate lost ecosystems. On the other hand, modern rangeland ecology emphasizes the often overriding importance of harsh climates. We visited two rewilding projects and three rangeland regions, sampling a total of 210 vegetation relevés in steppe and surrounding vegetation (grasslands, shrublands and forests) along an extensive climatic gradient across Yakutia, Russia. We analyzed species composition, plant traits, diversity indices and vegetation productivity, using partial canonical correspondence and redundancy analysis. Macroclimate was most important for vegetation composition, and microclimate for the occurrence of extrazonal steppes. Macroclimate and soil conditions mainly determined productivity of vegetation. Bison grazing was responsible for small-scale changes in vegetation through trampling, wallowing and debarking, thus creating more open and disturbed plant communities, soil compaction and xerophytization. However, the magnitude of effects depended on density and type of grazers as well as on interactions with climate and site conditions. Effects of bison grazing were strongest in the continental climate of Central Yakutia, and steppes were generally less affected than meadows. We conclude that contemporary grazing overall has rather limited effects on vegetation in northeastern Siberia. Current rewilding practices are still far from recreating a mammoth steppe, although large herbivores like bison can create more open and drier vegetation and increase nutrient availability in particular in the more continental Central Yakutian Plain. |
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