Suarez-Castro, A. F. | bioRxiv Science

bioRxiv2021

A global map of human pressures on tropical coral reefs

As human activities on the worlds oceans intensify, mapping human pressures is essential to develop appropriate conservation strategies and prioritize investments with limited resources. Here, we map non-climatic pressures on coral reefs using the latest quantitative data layers on fishing, nitrogen and sediment pollution, coastal and industrial development, and tourism. Across 54,596 coral reef pixels worldwide, we identify the top-ranked local pressure and estimate a cumulative pressure index mapped at 0.05-degree ([~]5 km) resolution. Fishing was the most common top-ranked pressure followed by water pollution (nutrients and sediments), although there is substantial variation by regions. We also find that local pressures are similar inside and outside a proposed global portfolio of coral reef climate refugia. We provide the best available information to inform critical conservation strategies and ensure local pressures are effectively managed to increase the likelihood of the persistence of coral reefs to climate change.

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↗