AGW Observer

Observations of anthropogenic global warming

New research – climate change impacts on biosphere (September 14, 2016)

Posted by Ari Jokimäki on September 14, 2016

Some of the latest papers on climate change impacts on biosphere are shown below. First a few highlighted papers with abstracts and then a list of some other papers. If this subject interests you, be sure to check also the other papers – they are by no means less interesting than the highlighted ones.


Increasing nest predation will be insufficient to maintain polar bear body condition inthe face of sea-ice loss (Dey et al. 2016)

Abstract: Climate change can influence interspecific interactions by differentially affecting species-specific phenology. In seasonal ice environments, there is evidence that polar bear predation of Arctic bird eggs is increasing because of earlier sea ice break-up, which forces polar bears into near-shore terrestrial environments where Arctic birds are nesting. Because polar bears can consume a large number of nests before becoming satiated, and because they can swim between island colonies, they could have dramatic influences on seabird and seaduck reproductive success. However, it is unclear whether nest foraging can provide an energetic benefit to polar bear populations, especially given the capacity of bird populations to redistribute in response to increasing predation pressure. In this study, we develop a spatially explicit agent-based model of the predator-prey relationship between polar bears and common eiders, a common and culturally important bird species for northern peoples. Our model is composed of two types of agents (polar bear agents, and common eider hen agents) whose movements and decision heuristics are based on species-specific bioenergetic and behavioral ecological principles, and are influenced by historical and extrapolated sea ice conditions. Our model reproduces empirical findings that polar bear predation of bird nests is increasing, and predicts an accelerating relationship between advancing ice break-up dates and the number of nests depredated. Despite increases in nest predation, our model predicts that polar bear body condition during the ice-free period will continue to decline. Finally, our model predicts that common eider nests will become more dispersed and will move closer to the mainland in response to increasing predation, possibly increasing their exposure to land-based predators, and influencing the livelihood of local people that collect eider eggs and down. These results show that predator-prey interactions can have non-linear responses to changes in climate, and provides important predictions of ecology change in Arctic ecosystems.

Lizards fail to plastically adjust nesting behavior or thermal tolerance as needed to buffer populations from climate warming (Telemaco et al. 2016)

Abstract: Although observations suggest the potential for phenotypic plasticity to allow adaptive responses to climate change, few experiments have assessed that potential. Modeling suggests that Sceloporus tristichus lizards will need increased nest depth, shade cover, or embryonic thermal tolerance to avoid reproductive failure resulting from climate change. To test for such plasticity, we experimentally examined how maternal temperatures affect nesting behavior and embryonic thermal sensitivity. The temperature regime that females experienced while gravid did not affect nesting behavior, but warmer temperatures at the time of nesting reduced nest depth. Additionally, embryos from heat-stressed mothers displayed increased sensitivity to high-temperature exposure. Simulations suggest that critically low temperatures, rather than high temperatures, historically limit development of our study population. Thus, the plasticity needed to buffer this population has not been under selection. Plasticity will likely fail to compensate for ongoing climate change when such change results in novel stressors.

Adapt, move, or die – how will tropical coral reef fishes cope with ocean warming? (Habary et al. 2016)

Abstract: Previous studies hailed thermal tolerance and the capacity for organisms to acclimate and adapt as the primary pathways for species survival under climate change. Here we challenge this theory. Over the past decade more than 365 tropical stenothermal fish species have been documented moving pole-ward, away from ocean warming hotspots where temperatures 2-3 °C above long-term annual means can compromise critical physiological processes. We examined the capacity of a model species – a thermally-sensitive coral reef fish, Chromis viridis (Pomacentridae) – to use preference behaviour to regulate its body temperature. Movement could potentially circumvent the physiological stress response associated with elevated temperatures and may be a strategy relied upon before genetic adaptation can be effectuated. Individuals were maintained at one of six temperatures (23, 25, 27, 29, 31 and 33 °C) for at least six weeks. We compared the relative importance of acclimation temperature to changes in upper critical thermal limits, aerobic metabolic scope, and thermal preference. While acclimation temperature positively affected the upper critical thermal limit, neither aerobic metabolic scope nor thermal preference exhibited such plasticity. Importantly, when given the choice to stay in a habitat reflecting their acclimation temperatures or relocate, fish acclimated to end-of-century predicted temperatures (i.e., 31 or 33 °C) preferentially sought out cooler temperatures, those equivalent to long-term summer averages in their natural habitats (~29 °C). This was also the temperature providing the greatest aerobic metabolic scope and body condition across all treatments. Consequently, acclimation can confer plasticity in some performance traits, but may be an unreliable indicator of the ultimate survival and distribution of mobile stenothermal species under global warming. Conversely, thermal preference can arise long before, and remain long after, the harmful effects of elevated ocean temperatures take hold and may be the primary driver of the escalating pole-ward migration of species.

Projections of climate change impacts on central America tropical rainforest (Lyra et al. 2016)

Abstract: Tropical rainforest plays an important role in the global carbon cycle, accounting for a large part of global net primary productivity and contributing to CO2 sequestration. The objective of this work is to simulate potential changes in the rainforest biome in Central America subject to anthropogenic climate change under two emissions scenarios, RCP4.5 and RCP8.5. The use of a dynamic vegetation model and climate change scenarios is an approach to investigate, assess or anticipate how biomes respond to climate change. In this work, the Inland dynamic vegetation model was driven by the Eta regional climate model simulations. These simulations accept boundary conditions from HadGEM2-ES runs in the two emissions scenarios. The possible consequences of regional climate change on vegetation properties, such as biomass, net primary production and changes in forest extent and distribution, were investigated. The Inland model projections show reductions in tropical forest cover in both scenarios. The reduction of tropical forest cover is greater in RCP8.5. The Inland model projects biomass increases where tropical forest remains due to the CO2 fertilization effect. The future distribution of predominant vegetation shows that some areas of tropical rainforest in Central America are replaced by savannah and grassland in RCP4.5. Inland projections under both RCP4.5 and RCP8.5 show a net primary productivity reduction trend due to significant tropical forest reduction, temperature increase, precipitation reduction and dry spell increments, despite the biomass increases in some areas of Costa Rica and Panama. This study may provide guidance to adaptation studies of climate change impacts on the tropical rainforests in Central America.

Interactive effects of temperature and pCO2 on sponges: from the cradle to the grave (Bennett et al. 2016)

Abstract: As atmospheric CO2 concentrations rise, associated ocean warming (OW) and ocean acidification (OA) are predicted to cause declines in reef-building corals globally, shifting reefs from coral-dominated systems to those dominated by less sensitive species. Sponges are important structural and functional components of coral reef ecosystems, but despite increasing field based evidence that sponges may be ‘winners’ in response to environmental degradation, our understanding of how they respond to the combined effects of OW and OA is limited. To determine the tolerance of adult sponges to climate change, four abundant Great Barrier Reef species were experimentally exposed to OW and OA levels predicted for 2100, under two CO2 Representative Concentration Pathways (RCPs). The impact of OW and OA on early life history stages was also assessed for one of these species to provide a more holistic view of species impacts. All species were generally unaffected by conditions predicted under RCP6.0, although environmental conditions projected under RCP8.5 caused significant adverse effects; with elevated temperature decreasing the survival of all species, increasing levels of tissue necrosis and bleaching, elevating respiration rates and decreasing photosynthetic rates. OA alone had little adverse effect, even under RCP8.5 concentrations. Importantly, the interactive effect of OW and OA varied between species with different nutritional modes, with elevated pCO2 exacerbating temperature stress in heterotrophic species but mitigating temperature stress in phototrophic species. This antagonistic interaction was reflected by reduced mortality, necrosis and bleaching of phototrophic species in the highest OW/OA treatment. Survival and settlement success of C. foliascens larvae were unaffected by experimental treatments, and juvenile sponges exhibited greater tolerance to OW than their adult counterparts. With elevated pCO2 providing phototrophic species with protection from elevated temperature, across different life-stages, climate change may ultimately drive a shift in the composition of sponge assemblages towards a dominance of phototrophic species.

Other papers

Stability in a changing world – palm community dynamics in the hyperdiverse western Amazon over 17 years (Olivares et al. 2016)

Recent climate hiatus revealed dual control by temperature and drought on the stem growth of Mediterranean Quercus ilex (Lempereur et al. 2016)

Environmental constraints on Holocene cold-water coral reef growth off Norway: Insights from a multi-proxy approach (Raddatz et al. 2016)

Projected shifts in fish species dominance in Wisconsin lakes under climate change (Hansen et al. 2016)

Phenological research of climate changes in the north part of Lithuania by the phenological garden of Šiauliai University (Klimienė et al. 2016)

Stream network geomorphology mediates predicted vulnerability of anadromous fish habitat to hydrologic change in southeast Alaska (Sloat et al. 2016)

Diatom assemblages reveal regional-scale differences in lake responses to recent climate change at the boreal-tundra ecotone, Manitoba, Canada (Shinneman et al. 2016)

Temperature sensitivity thresholds to warming and cooling in phenophases of alpine plants (Meng et al. 2016)

Relationships between climate, topography, water use and productivity in two key Mediterranean forest types with different water-use strategies (Helman et al. 2016)

Ant assemblages have darker and larger members in cold environments (Bishop et al. 2016)

Spring blooms in the Baltic Sea have weakened but lengthened from 2000 to 2014 (Groetsch et al. 2016)

Current and projected global distribution of Phytophthora cinnamomi, one of the world’s worst plant pathogens (Burgess et al. 2016)

Assessing drought-driven mortality trees with physiological process-based models (Hendrik & Maxime, 2016)

Global patterns in lake ecosystem responses to warming based on the temperature dependence of metabolism (Kraemer et al. 2016)

Additive effects of temperature and infection with an acanthocephalan parasite on the shredding activity of Gammarus fossarum (Crustacea: Amphipoda): the importance of aggregative behavior (Labaude et al. 2016)

Growth of northern deciduous trees under increasing atmospheric humidity: possible mechanisms behind the growth retardation (Sellin et al. 2016)

Responses of net primary productivity to phenological dynamics in the Tibetan Plateau, China (Wang et al. 2016)

Variation in White Stork (Ciconia ciconia) diet along a climatic gradient and across rural-to-urban landscapes in North Africa (Chenchouni, 2016)

Species-specific responses to climate change and community composition determine future calcification rates of Florida Keys reefs (Okazaki et al. 2016)

Aleppo pine forests from across Spain show drought-induced growth decline and partial recovery (Gazol et al. 2016)

Climate change will increase the naturalization risk from garden plants in Europe (Dullinger et al. 2016)

Coarse climate change projections for species living in a fine-scaled world (Nadeau et al. 2016)

Confounding effects of spatial variation on shifts in phenology (de Keyzer et al. 2016)

Climate warming reduces fish production and benthic habitat in Lake Tanganyika, one of the most biodiverse freshwater ecosystems (Cohen et al. 2016)

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