Jessie C. Buettel

Biodiversity losses and conservation responses in the Anthropocene

Biodiversity is essential to human well-being, but people have been reducing biodiversity throughout human history. Loss of species and degradation of ecosystems are likely to further accelerate in the coming years. Our understanding of this crisis is now clear, and world leaders have pledged to avert it. Nonetheless, global goals to reduce the rate of biodiversity loss have mostly not been achieved. However, many examples of conservation success show that losses can be halted and even reversed. Building on these lessons to turn the tide of biodiversity loss will require bold and innovative action to transform historical relationships between human populations and nature.

Emigration is costly, but immigration has benefits in human‐altered landscapes

Fragmented habitats are a signature of anthropogenically disturbed landscapes. When human activities act to disaggregate once-contiguous forest or other terrestrial ecosystems, and convert intervening spaces into a ‘matrix’ of agriculture, roads and urban areas, it can be difficult for resident species to sustain connected populations (Saunders, Hobbs & Margules 1991). Dispersal ability and inter-patch migration rates are therefore important determinants of a species’ ability to persist and navigate throughout these human-altered environments. But mobility can also be a double-edged sword (Fahrig 2007). Movement involves certain risk to individuals, resulting in costs to energy expenditure that amplifies with time spent moving, and increased mortality risk that has the potential to deplete source populations of potential future breeders. The trade-off between the benefits and costs of mobility in fragmented landscapes and its implications for extinction risk have consequently been a central problem for conservation.

Impact of intense disturbance on the structure and composition of wet-eucalypt forests: A case study from the Tasmanian 2016 wildfires

Fire is a key process in eucalypt communities, exerting a strong influence on the composition, structure and functioning of forests. Much of the research on the fire response of temperate, wet-sclerophyll trees in Australia comes from Victoria, where the dominant eucalypt is Eucalyptus regnans. In contrast, central and northern Tasmanian forests, dominated by Eucalyptus delegatensis, are relatively understudied. There is a need to determine whether Tasmanian wet-sclerophyll forests, though the same forest type in name, are functionally different in floristics and response to fire. Here we document the forest community response to a natural wildfire event in Tasmania—using opportunistic before/after control/impact (BACI) data from pre-existing monitoring plots. Uniting pre- and post-fire floristic data, we quantified mortality and regeneration of eucalypt, acacia and other dominant tree species, and tree ferns, Dicksonia antarctica, in response to wildfire. We also evaluated the density of eucalypt and acacia seedling establishment between burnt and unburnt forests, and quantified faunal responses to fire. Despite moderate-to-high intensity burning in patches across the plot, mortality of eucalypts, acacias and tree ferns due to fire were low. By contrast, fire-sensitive rainforest species showed low survival, though were able to persist in unburnt refugia. Eucalypt and acacia seedling regeneration was high in the burnt plot, suggesting that E. delegatensis forests regenerate without stand-replacing fire events. This contrasts to Victorian E. regnans forests, whose persistence is dependent on high-severity stand-replacing events. We also found some group-specific avifaunal and invertebrate responses to the fire event, which are broadly reflective of responses documented in other Victorian-based studies. Our results have implications for Tasmanian wet-forest silvicultural practices, which are based on the principle of stand-replacement after fire. The broader relevance of this work to forest ecology is in demonstrating the serendipitous opportunities that can arise with baseline monitoring plots.

Forecasting future global food demand: A systematic review and meta-analysis of model complexity

Predicting future food demand is a critical step for formulating the agricultural, economic and conservation policies required to feed over 9 billion people by 2050 while doing minimal harm to the environment. However, published future food demand estimates range substantially, making it difficult to determine optimal policies. Here we present a systematic review of the food demand literature-including a meta-analysis of papers reporting average global food demand predictions-and test the effect of model complexity on predictions. We show that while estimates of future global kilocalorie demand have a broad range, they are not consistently dependent on model complexity or form. Indeed, time-series and simple income-based models often make similar predictions to integrated assessments (e.g., with expert opinions, future prices or climate influencing forecasts), despite having different underlying assumptions and mechanisms. However, reporting of model accuracy and uncertainty was uncommon, leading to difficulties in making evidence-based decisions about which forecasts to trust. We argue for improved model reporting and transparency to reduce this problem and improve the pace of development in this field.

Astro-ecology? Shifting the interdisciplinary collaboration paradigm

We present a case study whereby ecological research on fallen trees in forest plots was advanced by a collaboration with astronomers working on the vector fields of stars and gas, and we propose a framework by which such novel collaborations can progress.