How planting trees can damage the environment?

Stanford university, 22nd June 2020 - Projects of plating large quantities of non-native, mono culture plantations has become very common to comeback the climate change pandemic. Recent research led by the Stanford University has no carbon sequestration benefits and there is significant correlation between the replacement of a natural ecosystem to larger non-native, monocultures with significant losses in the biodiversity. 

These monocultures are described as 'highly uniform agricultural systems that replaces natural ecosystems and their rich biodiversity' by Sandy Gauntlett of the Pacific Indigenous People Environment Coalition. 

The native fauna have taken centuries of evolution with their environment which creates a suitable habitat for these individuals in terms of food, shelter etc. 

Polyculture forests are said to be significantly more beneficial for biodiversity as they provide a larger realized niche for the fauna as they provide a greater diversity of shelters, food, leaf litter, habitat type suitable for a wide range of different fauna. Monocultures often provide an environment which benefits generalist species which are widespread and will then out compete the specialist species. This habitat will typically have little diversity with one dominant species. This is negative because we are replacing rare species that can only habituate in a small number of ecosystems with species that have no treat. 

Studies performed before and after transforming a native ecosystem into a monoculture plantation where it was discovered that there was a 40-60% decline in bird populations and a 25% decline in amphibian populations.

Studies published in 'Nature' has stated that youthful monoculture plantations may act as emitters. Old native forest climaxes are associated with storage of high volumes of carbon content, however, the disturbance and degradation resulting from replacing the previous ecosystem (similar to how disturbed peatlands act as methane emitters). These monocultures are typically raised for the purpose of reaching a nations timber production goals which will release much of the carbon stored which will often make these habitats release more carbon than it has stored throughout it's life. 

It would be significantly more environmentally friendly on all aspects if less trees would be planted and more efforts are put into raising native polyculture woodlands.

References

• University, S., 2020. When Planting Trees Threatens The Forest | Stanford News. [online] Stanford News. Available at: <https://news.stanford.edu/2020/06/22/planting-trees-threatens-forest/> [Accessed 28 July 2020].

• Butler, R., 2008. Monoculture Tree Plantations Are “Green Deserts” Not Forests, Say Activists. [online] Mongabay Environmental News. Available at: <https://news.mongabay.com/2008/09/monoculture-tree-plantations-are-green-deserts-not-forests-say-activists/> [Accessed 28 July 2020].

The Red Squirrel's are Back?!?!?!

As of the 15th of June, 2020, research led by National University of Ireland, Galway has recorded an increase in the native red squirrel population thanks to the growth in abundance to the native carnivore called pine martens in the Irish midlands. There is a significant correlation between the increase of pine martens and decrease of grey squirrels in habitats in the presence of red squirrels because of the grey squirrel's larger size, decreased agility and greater time spent on the ground foraging in comparison to the native red's. This interaction is a classic top-down trophic cascade where the top carnivores dictates the structure of the surrounding ecosystem. These pine martens were studied through a non-invasive, DNA analysis on the pine marten used to study the food consumed. It was discovered wood mice were the primary food source, followed by the grey squirrel and very few red squirrels. The reduction of the invasive American grey squirrel has resulted in an increase in the red squirrel population as grey's transmit a fatal parapox virus that they've built an immunity towards and they also consume all of the green acorns. Red squirrels can only consume green acorns as they  cannot digest mature acorns. This will put pressure onto the population of the red squirrels which will prevent them from breeding which will then increase grey squirrel populations further and so worsening the situation.

Queen's University, Belfast (QUB) also performed studies on this trophic cascade and back's this correlation between pine martens and grey squirrels. Studies performed in Northern Ireland (NI) are more important as it's predicted there will no longer be any red squirrels remaining in NI within the next few decades. This study predicts there will be an increase in grey squirrels in urban parks due to the lack of wooded areas in these parks. Joshua Twinning of QUB stated "As the pine maten does not occupy urban areas anywhere within it's European range, it (Pine martens) is not likely to be the sole solution to the invasive grey squirrel". 

https://www.thetimes.co.uk/article/first-they-cloned-dolly-the-sheep-now-they-are-targeting-grey-squirrels-xdjzm3rgb

References

• Nuigalway.ie. 2020. June - NUI Galway. [online] Available at: <http://www.nuigalway.ie/about-us/news-and-events/news-archive/2020/june/red-squirrels-making-comeback-as-return-of-native-pine-marten-spells-bad-news-for-invasive-grey-squirrel-1.html> [Accessed 16 July 2020].
• Dwyer, S., 2020. Pine Martens Could Be Solution To Saving Red Squirrels In Urban Areas. [online] TheJournal.ie. Available at: <https://www.thejournal.ie/grey-squirrel-and-pine-marten-relationship-5121288-Jun2020/> [Accessed 16 July 2020].
•   O'Sullivan, K., 2019. Good Neighbours: How Pine Martens Are Helping Red Squirrels Survive. [online] The Irish Times. Available at: <https://www.irishtimes.com/news/environment/good-neighbours-how-pine-martens-are-helping-red-squirrels-survive-1.3822153> [Accessed 16 July 2020].