Tagged: Arctic


Effects of warming and N addition on seedling establishment in tundra

Climate change is expected to cause (sub)arctic plant species to move polewards to track their climatic niche. However, rapid migration requires recruitment from seed, which is rare in arctic regions where most plants reproduce vegetatively. In a recent study published in AoB PLANTS, Milbau et al. examined whether recruitment from seed would improve under warmer and more fertile future conditions. They found that seedling establishment was barely affected by warming and fertilization, suggesting that (sub)arctic species may experience difficulties in tracking their climatic niche. Predictions of future species’ distributions in arctic regions based solely on abiotic factors may therefore overestimate...

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Plant conservation genetics in an Arctic archipelago

Small and peripheral populations often contain low levels of genetic variation. This may limit their ability to adapt to environmental change, including climate warming. In a recent study published in AoB PLANTS, Birkeland and colleagues show that many rare and threatened plant species in the High Arctic archipelago Svalbard harbour low levels of genetic variation. Most of them are probably relicts from the early Holocene warmer period. They have likely experienced strong genetic founder/bottleneck effects due to climatic limitations. Even though temperatures now are rising, it is highly uncertain whether this will be beneficial for these warmth-demanding species.

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Population genetics of purple saxifrage (Saxifraga oppositifolia L.) in the high Arctic archipelago of Svalbard

The genetic characteristics of species impact their capacity to maintain populations and colonize new areas, and the presence of genetic diversity is especially important for plant populations in highly stochastic environments like the Arctic. Purple saxifrage, Saxifraga oppositifolia, is a circumpolar, ecologically and morphologically variable species with a wide range of habitats. Although not endangered at the moment, climate change, the potential warming or drying of northern areas, and increased UV radiation could become a threat in the future. In a recent study published in AoB PLANTS, Pietiläinen and Korpelainen used DNA markers and sequencing to investigate patterns of genetic...

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Image: Hannes Grobe, Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany/Wikimedia Commons.

That sinking feeling…

Whilst forests – aided and abetted by cryptogams (see my previous post) – have a major role as biotic carbon sinks on land, in the oceans that role is largely down to the activity of cryptogamous phytoplankton, which ‘draw-down’ vast amounts of CO2 during photosynthesis. However – and unlike trees – much of that aquatic primary productivity is consumed by herbivores, which in turn are preyed upon by various levels of carnivores. Ultimately, a lot of the CO2 that is fixed is released quite soon thereafter in respiration. Which is why attempts to consign such fixed carbon that is retained...

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Rejoice, ‘tis the real Bloom’s Day (to be sure…)

June 16th is the date upon which certain individuals around the world celebrate Irish writer James Joyce’s 1904-set literary classic Ulysses. Termed Bloom’s Day – after Leopold Bloom, the famously impenetrable novel’s main character, whose Dublin comings-and-goings are minutely catalogued over a 24-hour period – this is only a day-long phenomenon. A recently discovered bloom of another – phytoplankton – kind, and which lasts far longer than one day, is reported by Kevin Arrigo et al. But such blooms – a ‘rapid increase or accumulation in the population of algae… in an aquatic system’  – are common enough, and the well-documented,...

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