Climate Change Induces Biodiversity

Quartz reports Climate change will force species to find new homes. We have to embrace it.
Excerpts in italics with my bolds.

During the last Ice Age, species adapted to warmer climes survived in refugia: places that, through some quirk of topography and geography, stayed temperate in a glacial world. By this century’s end, new refugia will emerge—locales where plants and animals will shelter from rising temperatures, protected until such time as they can proliferate again.

For that to happen, though, nature-loving people will need to be open-minded to change. After all, these places will become very different from what they are now.

“The important species turnover expected in northern protected areas emphasizes the hopelessness of trying to preserve a snapshot of today’s biodiversity,” write researchers led by biologist Dominique Berteaux of the Univery of Quebec in Rimouski. “This challenges the traditional paradigm of conserving the ecological integrity of national parks.”

In a study published in the journal Scientific Reports, Berteaux’s team model the likely near-future climate suitability of a 230,000-square-mile network of protected areas in Quebec for 529 species of birds, amphibians, plants, and trees. That’s only a portion of possible biodiversity, but it’s enough to signify larger trends—and by the year 2100, Quebec’s nature could be a jumble of existing and newly-arrived species.

The total number of species living in the region will soar by about 92%. An estimated 24% of species now found there will become locally extinct. Species turnover—a metric used by ecologists to represent these gains and losses—comes in at 55%. Those are just averages: Some places are predicted to experience less change, but others could have far more.

Reality is more complicated than models, of course, and the results are not intended to be exact predictions. Rather, they “provide the best-available indication of the strong pressure that climate change will impose on biodiversity,” write Berteaux and colleagues. There are several implications.

First and foremost, “northern protected areas should ultimately become important refuges for species tracking climate northward”—but only if they can get there. Urbanization and habitat fragmentation could block them, squeezing species between inhospitable climate to the south and impassable landscapes to the north. Protecting migration corridors is vital.

And once new species do arrive, ecological disruption is inevitable. Newcomers may degrade ecosystem function; they may also be necessary to preserve ecosystem function. These are not mutually exclusive propositions. “In this context,” write Berteaux’s team, “deciding which new species should be controlled and which should be tolerated or favored will represent an immense challenge.”

Ultimately it may make more sense to take a big-picture approach, protecting a diversity of habitats rather than worrying about particular species. It may also be sensible, says Berteaux, to be more welcoming of newcomers than conservationists now tend to be.

People tend to “see all the bad things they could bring. We forget that nature is always transient,” said Berteaux when asked about dismay over the northward expansion of beavers into the Arctic—something not discussed in this study, but emblematic of its themes. “Change has to be accepted and conservation must be thought in this context of permanent change.”

Source: Berteaux et al. “Northern protected areas will become important refuges for biodiversity tracking suitable climates.” Scientific Reports, 2018.

Berteaux et al provide a summary of results and a plan for adapting.

The Northern Biodiversity Paradox predicts that, despite its globally negative effects on biodiversity, climate change will increase biodiversity in northern regions where many species are limited by low temperatures. We assessed the potential impacts of climate change on the biodiversity of a northern network of 1,749 protected areas spread over >600,000 km2 in Quebec, Canada. Using ecological niche modeling, we calculated potential changes in the probability of occurrence of 529 species to evaluate the potential impacts of climate change on (1) species gain, loss, turnover, and richness in protected areas, (2) representativity of protected areas, and (3) extent of species ranges located in protected areas.

We predict a major species turnover over time, with 49% of total protected land area potentially experiencing a species turnover >80%. We also predict increases in regional species richness, representativity of protected areas, and species protection provided by protected areas. Although we did not model the likelihood of species colonising habitats that become suitable as a result of climate change, northern protected areas should ultimately become important refuges for species tracking climate northward. This is the first study to examine in such details the potential effects of climate change on a northern protected area network.

Conservation implications
The protected areas of Quebec are poised to becoming biodiversity refuges of continental importance, which has four imbricated conservation implications. First, the efficiency of the Quebec network of protected areas in preserving biodiversity could be compromised by limitations to species dispersal. A biodiversity deficit could occur in some areas of Quebec if many species are trapped for decades or centuries between rapid retreat at their southern edge and slow advance at their northern edge38. Therefore, increasing connectivity between protected areas and preserving and restoring potential immigration corridors are priorities.

Second, colonizing species favour protected over unprotected sites and managers of protected areas in northern regions will have to deal with an increasing number of new immigrant species. Newly arriving species can impact negatively ecosystem structure and function. At the same time, self-sustaining populations of non-native species could become necessary in some protected areas to ensure local ecosystem functions and services if historical communities are deeply modified. In this context, deciding which new species should be controlled and which should be tolerated or favored will represent an immense challenge.

Third, in Canada as in several other high-latitude countries, northern peripheral species are already a significant portion of species at risk. These species can have negative impacts on native communities locally, but from a wider point of view, genetic diversity of leading-edge peripheral populations may help species to cope with climate change. Hence, assigning conservation status to rare and recently naturalized species is a thorny issue, and conservation value of rare new species should be considered in a long-term continental perspective rather than short-term national perspective.

Fourth, the important species turnover expected in northern protected areas emphasizes the hopelessness of trying to preserve a snapshot of today’s biodiversity. This challenges the traditional paradigm of conserving the ecological integrity of National Parks. Designing conservation to preserve site resilience and a diversity of physical features and abiotic conditions that are associated with ecological diversity could be a valuable biodiversity conservation strategy under climate change.

Source: Phanerozoic_Biodiversity.png Author: SVG version by Albert Mestre

See Also:  Sixth Mass Genesis, Not Extinction

via Science Matters

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July 5, 2018 at 04:21PM

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