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As the United Nations develops a post-2020 global biodiversity framework for the Convention on Biological Diversity, attention is focusing on how new goals and targets for ecosystem conservation might serve its vision of 'living in harmony with nature'1,2. Advancing dual imperatives to conserve biodiversity and sustain ecosystem services requires reliable and resilient generalizations and predictions about ecosystem responses to environmental change and management3. Ecosystems vary in their biota4, service provision5 and relative exposure to risks6, yet there is no globally consistent classification of ecosystems that reflects functional responses to change and management. This hampers progress on developing conservation targets and sustainability goals. Here we present the International Union for Conservation of Nature (IUCN) Global Ecosystem Typology, a conceptually robust, scalable, spatially explicit approach for generalizations and predictions about functions, biota, risks and management remedies across the entire biosphere. The outcome of a major cross-disciplinary collaboration, this novel framework places all of Earth's ecosystems into a unifying theoretical context to guide the transformation of ecosystem policy and management from global to local scales. This new information infrastructure will support knowledge transfer for ecosystem-specific management and restoration, globally standardized ecosystem risk assessments, natural capital accounting and progress on the post-2020 global biodiversity framework.

Little is known about odonate ecology and phenology in warm mediterranean climates where most wetlands are intermittent. We identified variables associated with the presence, relative abundance, assemblage composition and body size of odonates in spring and summer, to understand the influence of intermittency and season. We hypothesized that size at eclosion would be smaller in seasonal wetlands in summer due to time stress caused by drying. Nymphs, exuviae and adults were sampled in spring and summer from 22 intermittent and perennial suburban wetlands in south‐western Australia. Spatial and environmental variables within and between wetlands were measured and associated with adult and nymph distributions. Exuviae were collected to quantify size at eclosion. As in temperate perennial wetlands, wetland‐scale variables (submerged, emergent and terrestrial vegetation, water temperature) were most strongly associated with assemblage composition of adults and nymphs, but landscape‐scale variables (distance to nearest patch of native vegetation, distance to nearest large lake) were also associated with adult assemblages. Two abundant dragonfly (Orthetrum caledonicum Libellulidae, Hemicordulia tau Hemicorduliidae) and one damselfly (Xanthagrion erythroneurum Coenagrionidae) species emerged at smaller body sizes in summer than spring, but from both intermittent and perennial wetlands. Consequently, declining photoperiod and warmer summer temperatures, rather than wetland drying, probably caused reduced size at eclosion. Although the influence of vegetation, temperature and photoperiod on odonate assemblages appears similar in temperate and mediterranean climates, odonate phenology differs markedly. Fitness cost of emerging at a smaller adult size may be outweighed by the increased likelihood of successfully reaching emergence in drying waterbodies in summer. More field data on size at eclosion in warm climate regions, and laboratory experiments manipulating temperature and photoperiod, are needed to confirm the generality of patterns shown here. [ABSTRACT FROM AUTHOR]

Crayfish perform important roles within freshwater ecosystems, including in regions where global warming is causing prolonged drying of waterbodies. However, little is known about responses of crayfish to habitat drying from both a behavioural and physiological perspective. We compared burrowing ability, survival and metabolism of the crayfish Cherax quinquecarinatus from a seasonal stream and a perennial stream. Burrowing ability and crayfish survival were quantified in a mesocosm experiment contrasting sediment type (sand vs. clay/sand mixture) and water regime. Aerobic scope, standard metabolic rate (SMR) and maximum metabolic rate (MMR) were also compared using intermittent flow respirometry. Crayfish from the seasonal stream showed limited burrowing ability but higher survival in the drying treatment, while the perennial stream crayfish burrowed strongly in the clay/sand sediment. Higher survival suggests that crayfish from seasonal streams might be physiologically better adapted to drying. Larger crayfish burrowed more proficiently, reaching the saturated hyporheic zone refuge in the clay/sand sediment treatment. SMR/MMR/aerobic scope did not differ between populations or respirometry runs; however, SMR differed between individuals, perhaps due to personality traits. There was a significant negative relationship between MMR/aerobic scope and weight. Sediment type may limit C. quinquecarinatus burrowing and persistence through drying. Crayfish populations did not differ in terms of metabolism; however, crayfish from seasonal habitats may possess more efficient physiological adaptations to drying. This study highlights the need for greater research attention on the effects of climatic drying on both the behaviour and the physiology of species exposed to climate change. [ABSTRACT FROM AUTHOR]

The sheltered environments of coastal embayments have played a vital role for humans for millennia and their resources have underpinned modern industrial development globally. Their effective management and restoration remains an enormous challenge, owing, in part, to lack of recognition of the threshold changes that occurred in many bays prior to scientific study (i.e. >50 years ago). Advances in marine extraction technologies and increased clearing of catchments for agriculture and urbanisation in recent history (∼400 years) have resulted in profound physical, chemical and biological changes to these ecosystems. More recently, the integration of ecology, history, archaeology, economics and fisheries science have contributed to the emerging field of 'marine historical ecology' (MHE). The synthesis of information from these different disciplines can markedly improve knowledge of past ecosystem condition, thereby assisting managers to set realistic goals for environmental restoration to improve biodiversity and ecosystem function. This paper reviews historical knowledge of long-term environmental degradation processes in coastal embayments, summarising the wide range of methods and techniques used as evidence and providing examples from around the world, thereby illustrating the need for longer time-frames of reference for contemporary restoration ecology. Coastal bays have supported human communities for millennia. Their effective management and restoration remains a challenge, in part as a result of human impacts that occurred before scientific studies. This review examines the historical ecology of bays and the tools and techniques used to discover environmental change to support effective management and restoration. [ABSTRACT FROM AUTHOR]

Climate change is altering hydrologic regimes globally. In the Mediterranean climate region of south‐western Australia (SWA), climate drying has caused many perennial streams to switch to intermittent flow regimes. Shifts in flow regime are expected to alter physical and biological processes in streams, including litter decomposition, which is the basis of detrital food webs.Decomposition of jarrah (Eucalyptus marginata) leaves and associated macroinvertebrates, were measured over 320 days in 2018–19 using leaf bags in four headwater streams in SWA. Two streams retained perennial reaches and two were formerly perennial streams that are now intermittent. Pre‐planned comparisons that formed a partial multiple before–after, control–impact design were used to compare the results to an experiment conducted in 1982–83 in some of the same streams when all were perennially flowing. Both experiments used coarse and fine‐mesh bags containing 10 g of dry leaves.In one perennial stream, coarse bags lost more weight than fine bags at the last sampling time only, when shredding caddisflies arrived on the leaf bags. In the other perennial stream, leaf‐mining chironomids entered fine‐mesh bags and accelerated decomposition so that they lost more weight than the coarse‐mesh bags. There was no difference in weight loss between fine and coarse‐mesh leaf bags in the two intermittent streams.In 2018–19, decomposition was slower in dry reaches of intermittent streams than in perennial reaches. Leaf weight loss increased with the resumption of flow in intermittent streams, so that by the end of the experiment, similar amounts of leaf weight had been lost in intermittent and perennial reaches. Thus, although the temporal pattern of decomposition differed between intermittent and perennial reaches, after 320 days, they had reached a similar endpoint.Over similar experimental duration, mean leaf weight remaining in perennial reaches at the end of the experiment did not differ between the 1982–83 study and 2018–19, showing that leaf decomposition had not changed in reaches that retained perennial flow. As mean leaf weight remaining also did not differ between intermittent and perennial streams in 2018–19, leaf decomposition was robust to flow regime change. However, since 1982–83, these streams have lost populations of shredding caddisflies and stoneflies, which were replaced by other shredders (e.g. leaf mining chironomids Stenochironomus sp.), showing that there was some redundancy amongst shredder species.As climate change progresses, drying flow regimes will become commonplace in Mediterranean (and other) climate regions globally. This study indicates that litter decomposition may be maintained as streams transition to intermittency although shredder species may change. However, the impact of shredding species on leaf decomposition varies amongst studies, so effects of the loss of shredder species sensitive to drying may also vary, and in some cases their loss may substantially alter ecosystem processes. [ABSTRACT FROM AUTHOR]