Does climate warming favor early season species?



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Does climate warming favor early season species?

The study published on the Frontiers in plant science, entitled Does Climate Warming Favor Early Season Species? explains in his research: "Plant species that start early in spring are generally more responsive to rising temperatures, raising concerns that climate warming may favor early season species and result in altered interspecific interactions and community structure and composition.

This hypothesis is based on changes in spring phenology and therefore active growing season length, which would not be indicative of possible changes in growth as would changes in cumulative forcing temperatures (growing degree days / hours) in the Northern Hemisphere.

In this study we analyzed the effects of a moderate climate warming (2 ° C warmer than the 1981-2010 baseline) on the leaf-out of hypothetical species without chilling restriction and actual plant species with different chilling and forcing requirements in different parts of the globe.

In both cases, early season species had larger phenological shifts due to low leaf-out temperatures, but accumulated fewer forcing gains (changes in cumulative fo rcing temperatures by warming) from those shifts because of their early spring phenology.

Leaf-out time was closely associated with leaf-out temperatures and therefore plant phenological responses to climate warming. All plant species would be equally affected by climate warming in terms of total forcing gains added from higher temperatures when forcing gains occurring between early and late season species are included.

Our findings will improve the understanding of possible mechanisms and consequences of differential responses in plant phenology to climate warming."

Due to the acidification of the oceans, marine fauna is endangered

The lowering of the marine pH creates the phenomenon of coral bleaching; the calcium carbonate that makes up shells, molluscs, crustaceans and even coral, decreases in relation to the increase in acidity, thus losing the algae that live above the surface of the organism, leading it to death.

Although many organisms suffer from this increasing acidification, some photosynthetic organisms benefit from it. One case is represented by diatoms; that is microscopic algae belonging to phytoplankton. For these organisms, the increase of CO2 in water increases their ability to carry out their own photosynthesis processes.

These processes can be carried out if in the presence of certain environmental conditions. The research: Major loss of coralline algal diversity in response to ocean acidification, published on the Global change biology, said us: "Calcified coralline algae are ecologically important in rocky habitats in the marine photic zone worldwide and there is growing concern that ocean acidification will severely impact them.

Laboratory studies of these algae in simulated ocean acidification conditions have revealed wide variability in growth, photosynthesis and calcification responses, making it difficult to assess their future biodiversity, abundance and contribution to ecosystem function.

Here, we apply molecular systematic tools to assess the impact of natural gradients in seawater carbonate chemistry on the biodiversity of coralline algae in the Mediterranean and the NW Pacific, link this to their evolutionary history and evaluate their potential future biodiversity and abundance.

We found a decrease in the taxonomic diversity of coralline algae with increasing acidification with m ore than half of the species lost in high pCO2 conditions. S porolithales is the oldest order (Lower Cretaceous) and diversified when ocean chemistry favored low Mg calcite deposition; it is less diverse today and was the most sensitive to ocean acidification.

Corallinales were also reduced in cover and diversity but several species survived at high pCO2; it is the most recent order of coralline algae and originated when ocean chemistry favored aragonite and high Mg calcite deposition.

The sharp decline in cover and thickness of coralline algal carbonate deposits at high pCO2 highlighted their lower fitness in response to ocean acidification. Reductions in CO2 emissions are needed to limit the risk of losing coralline algal diversity. "