Biology subjects

Allan, J. R.

Publications and source records attributed to Allan, J. R..

6 recordsLinked to original sources

bioRxiv2021

The role of elections as drivers of tropical deforestation

Tropical forests support immense biodiversity and provide essential ecosystem services for billions of people. Despite this value, tropical deforestation continues at a high rate. Emerging evidence suggests that elections can play an important role in shaping deforestation, for instance by incentivising politicians to allow increased utilisation of tropical forests in return for political support and votes. Nevertheless, the role of elections as a driver of deforestation has not been comprehensively tested at broad geographic scales. Here, we created an annual database from 2001 to 2018 on political elections and forest loss for 55 tropical nations and modelled the effect of elections on deforestation. In total, 1.5 million km2 of forest was lost during this time period, and the rate of deforestation increased in 37 (67%) of the analysed countries. Deforestation was significantly lower in years with presidential or lower chamber elections compared to non-election years, which is in contrast to previous local-scale studies. Moreover, deforestation was significantly higher in presidential or lower chamber elections that are competitive (i.e. when the opposition can participate in elections and has a legitimate chance to gain governmental power) compared to uncompetitive elections. Our results document a pervasive loss of tropical forests and suggest that competitive elections are potential drivers of deforestation. We recommned that organisations monitoring election transparency and fairness should also monitor environmental impacts such as forest loss, habitat destruction and resource exploitation. This would benefit the tracking of potential illegal vote buying with natural resources.

ecology↗

bioRxiv2021

Limiting the loss of terrestrial ecosystems to safeguard nature for biodiversity and humanity

Humanity is on a pathway of unsustainable loss of the natural systems upon which we, and all life, rely. To date, global efforts to achieve internationally-agreed goals to reduce carbon emissions, halt biodiversity loss, and retain essential ecosystem services, have been poorly integrated. However, these different goals all rely on preserving natural ecosystems. Here, we show how to unify these goals by empirically deriving spatially-explicit, quantitative area-based targets for the retention of natural terrestrial ecosystems. We found that at least 67 million km2 of Earths natural terrestrial ecosystems (~79% of the area remaining) require retention - via a combination of strict protection but more prominently through sustainably managed land use regimes complemented by restoration actions - to contribute to biodiversity, climate, soil and freshwater objectives under four United Nations Resolutions. This equates to retaining natural ecosystems across ~50% of the total terrestrial (excluding Antarctica) surface of Earth. Our results show where retention efforts could be focussed to contribute to multiple goals simultaneously. The retention targets concept that we present explicitly recognises that such management can and should co-occur alongside and be driven by the people who live in and rely on places where natural and semi-natural ecosystems remain on Earth.

ecology↗

bioRxiv2020

Threatened terrestrial vertebrates are exposed to human pressures across 94% of Europe's protected land

Protected areas (PAs) are the last refuges for wild biodiversity, yet human pressures (or threats) are increasingly prevalent within their boundaries. Human pressures have the potential to negatively impact species and undermine their conservation, but their overlap with sensitive threatened species in PAs remains rarely quantified. Here, we analyse the co-occurrence of nineteen threatening human activities within the distributions of 146 threatened terrestrial vertebrates in the European Union (EU), accounting for species-specific sensitivities to each pressure and thereby mapping potential human impacts on species within EU PAs. We find that human pressures extend across > 1.022 million km2 (94.5%) of EU protected land, with potential negative impacts on threatened species across 1.015 million km2 (93.8%). A total of 122 out of 146 species (84%) have > 50% of their EU protected ranges potentially impacted, and 83 out of 146 species (57%) more than 90% of their protected range. More species have a smaller proportion of their protected range potentially impacted in Natura2000 sites than in non-Natura2000 sites, and the same is true for species in nature reserves and wilderness areas compared to less strictly managed PAs. Our results show that threatened species in Europes PAs are exposed to immense human pressures, and suggest that areas designated for species conservation are ineffective for halting biodiversity decline. We recommend that the EU Biodiversity Strategy develops and enforces a comprehensive PA threat management program to reduce the negative impacts of human activities on wildlife in European protected lands.

ecology↗

bioRxiv2020

Change in terrestrial human footprint drives continued loss of intact ecosystems

Our ability to map humanitys influence across Earth has evolved, thanks to powerful computing, a network of earth observing satellites, and new bottom-up census and crowd-sourced data. Here, we provide the latest temporally inter-comparable maps of the terrestrial Human Footprint, and assessment of change in human pressure at global, biome, and ecoregional scales. In 2013, 42% of terrestrial Earth could be considered relatively free of anthropogenic disturbance, and 25% could be classed as wilderness (the least degraded end of the human footprint spectrum). Between 2000 and 2013, 1.9 million km2 - an area the size of Mexico - of land relatively free of human disturbance became highly modified. The majority of this occurred within tropical and subtropical grasslands, savannah, and shrubland ecosystems, but the rainforests of Southeast Asia also underwent rapid modification. Our results show that humanitys footprint is eroding Earths last intact ecosystems, and greater efforts are urgently needed to retain them.

ecology↗

bioRxiv2020

Only ten percent of the global terrestrial protected area network is connected via intact land

Land free of direct anthropogenic disturbance is considered essential for achieving biodiversity conservation outcomes but is rapidly eroding. In response, many nations are increasing their protected area estates but little consideration is given to the context of the surrounding landscape. This is despite the fact that connectivity between protected areas is critical in a changing climate and mandated in international protected area targets. By utilizing the latest human pressure assessment, which shows that [~]40% of the terrestrial planet is still intact, and a connectivity method, we found just 9.7% of Earths terrestrial protected network can be considered connected. On average, 11% of each nations protected area estate is connected via intact land. As the global community commits to bolder action on abating biodiversity loss, only an increased focus on landscape-scale habitat retention and restoration efforts will ensure those critical areas safeguarded for conservation outcomes will remain (or become) connected. One Sentence SummaryOnly 9.7% of the global protected area network can be considered connected by intact land.

ecology↗

bioRxiv2019

Conservation attention necessary across at least 44% of Earth’s terrestrial area to safeguard biodiversity

More ambitious conservation efforts are needed to stop the global biodiversity crisis. Here, we estimate the minimum land area to secure important sites for terrestrial fauna, ecologically intact areas, and the optimal locations for representation of species ranges and ecoregions. We discover that at least 64 million km2 (44% of terrestrial area) requires conservation attention. Over 1.8 billion people live on these lands so responses that promote agency, self-determination, equity, and sustainable management for safeguarding biodiversity are essential. Spatially explicit land-use scenarios suggest that 1.3 million km2 of land requiring conservation could be lost to intensive human land-uses by 2030, which requires immediate attention. However, there is a seven-fold difference between the amount of habitat converted under optimistic and pessimistic scenarios, highlighting an opportunity to avert this crisis. Appropriate targets in the post-2020 Global Biodiversity Framework to ensure conservation of the identified land would contribute substantially to safeguarding biodiversity.

ecology↗