Biology subjects

Sanderson, F. J.

Publications and source records attributed to Sanderson, F. J..

3 recordsLinked to original sources

bioRxiv2025

Shifting baselines increase the risk of misinterpreting biodiversity trends

Ecological studies quantifying the impact of land-use change on biodiversity may be sensitive to the choice of reference points - or baselines - particularly when sampling across human land-use gradients and other space-for-time comparisons. Much depends on whether the chosen baseline has already undergone shifts in species composition because of hunting, habitat loss and degradation. However, few studies have assessed the influence of shifting baselines on estimates of anthropogenic impacts. Using new survey data from five West African land-use gradients, we examine how habitat patch size and structure influences the estimated impact of land-use change on bird species richness and functional diversity. We show that smaller forests have already lost many forest-dependent birds, particularly those with large body size or specialised ecological niches, leading to reduced estimates of biodiversity loss after deforestation. The steepest biodiversity loss was found in mid-sized forests whereas relatively shallow declines were estimated for the most extensive forests - despite their richer taxonomic and functional diversity. In these larger forest blocks, accurate estimates of biodiversity loss may require longer transects extending beyond the biodiversity shadow caused by the more extensive spillover of forest species into the surrounding landscape, potentially linked to source-sink dynamics. These findings suggest that biodiversity assessments are highly sensitive to baseline selection and transect design, highlighting the risk of underestimating land-use impacts unless shifting baselines are carefully considered.

ecology↗

bioRxiv2024

Predicting near-future deforestation in West African Key Biodiversity Areas to inform conservation urgency

Site-based protection is a cornerstone of 21st century conservation and a core component of global biodiversity conservation targets. However, loss of tropical forests, the most biodiverse of habitats, is a major threat to such sites. Here, we predict near-future deforestation risk in 113 Key Biodiversity Areas (KBAs) - sites of objectively defined global conservation importance - in the Guinean Forest biodiversity hotspot and identify those factors associated with loss. We find that (i) KBAs in the Guinean Forests have lost over 265,000 hectares of forest cover over the past decade, with those in Cote dIvoire experiencing the highest forest loss; (ii) future deforestation risk is highest among KBAs in Liberia and Cote dIvoire (on average 10% predicted loss across KBAs), where some are predicted to lose over a fifth of remaining forest cover by 2033. Models indicate that deforestation is highly contagious, with historical forest loss effectively predicting further adjacent loss, and that forest fragmentation and ease of human access also increased the localised deforestation risk. Conversely, predicted forest loss was lower in sites under some form of conservation protection. Our methods to predict near-future hotspots of deforestation risk in KBAs are reproducible and therefore applicable to other biodiversity hotspots. In the Guinean forests, our results highlight where conservation interventions to mitigate forest loss should be urgently prioritised.

ecology↗

bioRxiv2020

The environmental impacts of palm oil and its alternatives

The destruction of ecosystems for vegetable oil production represents a major cause of global biodiversity loss and greenhouse gas emissions 1. Over the last two decades, oil palm, in particular, has caused societal concern due to its high impacts on biodiverse and carbon-dense tropical rainforests 2-8, leading to calls to source vegetable oils from alternative oil-producing crops. However, given the high yields of oil palm, how does that damage compare with other oil crops that require more land? Here, we estimate the carbon and biodiversity footprints, per unit of oil produced, of the worlds five major vegetable oil crops. We find that oil palm has the lowest carbon loss and species richness loss per-tonne-oil, but has a larger impact on range-restricted species than sunflower and rapeseed. We go on to identify global areas for oil crop expansion that will minimise future carbon and biodiversity impacts, and argue that closing current yield gaps and optimising the location of future growing areas will be much more effective at reducing future environmental impacts of global vegetable oil production than substituting any one crop for another.

ecology↗