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Fire management is increasingly focusing on introducing heterogeneity in burning patterns under the assumption that "pyrodiversity begets biodiversity." This concept has been formalized as patch mosaic burning (PMB), in which fire is manipulated to create a mosaic of patches representative of a range of fire histories to generate heterogeneity across space and time. Although PMB is an intuitively appealing concept, it has received little critical analysis. Thus we examined ecosystems where PMB has received the most attention and has been the most extensively implemented: tropical and subtropical savannas of Australia and Africa. We identified serious shortcomings of PMB: the ecological significance of different burning patterns remains unknown and details of desired fire mosaics remain unspecified. This has led to fire-management plans based on pyrodiversity rhetoric that lacks substance in terms of operational guidelines and capacity for meaningful evaluation. We also suggest that not all fire patterns are ecologically meaningful: this seems particularly true for the highly fire-prone savannas of Australia and South Africa. We argue that biodiversity-needs-pyrodiversity advocacy needs to be replaced with a more critical consideration of the levels of pyrodiversity needed for biodiversity and greater attention to operational guidelines for its implementation.

The tropics contain the overwhelming majority of Earth's biodiversity: their terrestrial, freshwater and marine ecosystems hold more than three-quarters of all species, including almost all shallow-water corals and over 90% of terrestrial birds. However, tropical ecosystems are also subject to pervasive and interacting stressors, such as deforestation, overfishing and climate change, and they are set within a socio-economic context that includes growing pressure from an increasingly globalized world, larger and more affluent tropical populations, and weak governance and response capacities. Concerted local, national and international actions are urgently required to prevent a collapse of tropical biodiversity.

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Although many taxa show a latitudinal gradient in richness, the relationship between latitude and species richness is often asymmetrical between the northern and southern hemispheres. Here we examine the latitudinal pattern of species richness across 1003 local ant assemblages. We find latitudinal asymmetry, with southern hemisphere sites being more diverse than northern hemisphere sites. Most of this asymmetry could be explained statistically by differences in contemporary climate. Local ant species richness was positively associated with temperature, but negatively (although weakly) associated with temperature range and precipitation. After contemporary climate was accounted for, a modest difference in diversity between hemispheres persisted, suggesting that factors other than contemporary climate contributed to the hemispherical asymmetry. The most parsimonious explanation for this remaining asymmetry is that greater climate change since the Eocene in the northern than in the southern hemisphere has led to more extinctions in the northern hemisphere with consequent effects on local ant species richness.

Summary1. Despite the fact that fire is considered an important disturbance in savannas across the world and is used widely as a management tool in conservation areas, little is known about the effects of burning on their insect communities. 2. This study made use of a 50-year fire experiment to investigate the responses of ant assemblages to long-term burning regimes. The effects of fire frequency, season and time since fire (fuel age) were tested on epigaeic ants across three savanna vegetation types (Mopane woodland, Acacia savanna and Terminalia woodland) in Kruger National Park, South Africa. 3. There was no significant effect of burning on mean ant species richness and abundance between treatments, although there were significant differences in ant assemblage composition between burned (treatment) and unburned (control) plots. The effects of season, frequency of burn and plot age on assemblage structure were weak and often not significant. 4. Epigaeic ant assemblages in this savanna system appeared to be highly resistant and resilient to burning. The response of ants to fire was linked to changes in habitat cover and structure: the effect of fire on vegetation and ants was less pronounced in lower rainfall areas, where differences in vegetation structure between burnt and unburnt plots were less pronounced than in higher rainfall areas. 5. Synthesis and applications. The effect of fire on ant assemblages in the mid-to northern Kruger National Park depends on whether a patch burns or not, rather than the specifics of the burning treatment. Thus, conservation managers can focus concerns regarding the subtleties of fire regimes on other taxa or areas of particular concern.

Protected areas provide major benefits for humans in the form of ecosystem services, but landscape degradation by human activity at their edges may compromise their ecological functioning. Using multiple lines of evidence from 40 years of research in the Serengeti-Mara ecosystem, we find that such edge degradation has effectively “squeezed” wildlife into the core protected area and has altered the ecosystem’s dynamics even within this 40,000-square-kilometer ecosystem. This spatial cascade reduced resilience in the core and was mediated by the movement of grazers, which reduced grass fuel and fires, weakened the capacity of soils to sequester nutrients and carbon, and decreased the responsiveness of primary production to rainfall. Similar effects in other protected ecosystems worldwide may require rethinking of natural resource management outside protected areas.

Wildfires underpin the dynamics and diversity of many ecosystems worldwide, and plants show a plethora of adaptive traits for persisting recurrent fires. Many fire-prone ecosystems also harbor a rich fauna; however, knowledge about adaptive traits to fire in animals remains poorly explored. We review existing literature and suggest that fire is an important evolutionary driver for animal diversity because (1) many animals are present in fire-prone landscapes and may have structural and phenotypic characters that contribute to adaptation to these open landscapes; and (2) in some cases, animals from fire-prone ecosystems may show specific fire adaptations. While there is limited evidence on morphological fire adaptations in animals, there is evidence suggesting that different behaviors might provide a rich source of putative fire adaptations; this is because, in contrast to plants, most animals are mobile, unitary organisms, have reduced survival when directly burnt by fire and can move away from the fire. We call for research on fire adaptations (morphological, behavioral, and physiological) in animals, and emphasize that in the animal kingdom many fire adaptations are likely to be behavioral. While it may be difficult to discern these adaptations from other animal behaviors, making this distinction is fundamental if we want to understand the role of fire in shaping biodiversity. Developing this understanding is critical to how we view and manage our ecosystems in the face of current global and fire regime changes.