P.S.....

My grandma sent me this video today and as soon as I watched it, I had to post it here.  I was hoping it would have a happy ending about our planet - instead it's pretty grim but very powerful... anyway hope you enjoy...

OVER AND OUT!

Time to say goodbye...!

For the last 13 weeks I have been keeping this blog about species distribution and how ranges are likely to change with climate variations.  I have investigated past, present and future changes in population ranges of both plants and animals.  I have really enjoyed blogging and have having never written a blog before, think I have discovered my blogging style.  When I am most inspired by something I have read or watched I wanted to blog about it straight away.  This often led to other blog ideas and so often I would blog several times a week.  Other times I would blog less as I had less inspiration!  Never the less, I have learnt a lot since I started this blog, and have gained a much wider knowledge in this area which still persists to amaze and interest me!

My views have been changed since writing this blog.  I started with the idea because I thought that species moving pole-wards and to higher altitudes was only a recent phenomenon.  I began this blog with knowledge of previous range shifts due to climate variations (i.e. during the ice age) but thought that these were on a much smaller scale and at a much slower rate than current levels.  I believed that range shifts had occurred previously but would have taken centuries or millennia to show great movement (unlike the patterns of the present day with the average species moving at 18km pole-wards per decade and 5-10m upwards on slopes).  However, while keeping this blog I have realised that species, if possible, have and always will shift their ranges with climate change.

 

I have realised the more important factor in this phenomena is not itself, or how quickly it is occurring, but that combined with human interference it could be fatal to many species.  In the past, before humans as we currently know them existed, animals and plants could expand and contract their ranges much easier as there were far less barriers that could interfere this.  Oceans are a large natural barrier to land-bound species, however many human barriers now exist that are preventing species from shifting their ranges.  These include urban areas (from small roads to whole cities), cropland (deforestation is a major problem) and other barriers such as dams.  The combination of climate change forcing species to shift their ranges, and human actions (i.e. deforestation) preventing easy movement of these species is the largest problem.

In order to prevent a near future of mass extinction, great amounts of consideration during future planning will have to be taken.  Assisted migration is one idea – humans ‘helping’ species shift their ranges by moving individuals to new suitable areas which naturally they wouldn’t be able to reach due to barriers.  In theory, this idea seems very viable – however, in reality it is not simple.  Generalist species will be the easiest to relocate as they are more adaptable and have a larger number of conditions they can survive in.  However, specialist species may not be able to adapt to other areas, or may only survive on one prey which cannot be relocated.  Another idea is conservation areas which will need large amounts of planning to incorporate future changes in climate.  This was particularly interesting to me as it was not an idea I had thought about before, and is quite significant in protecting biodiversity and rare species in the future.

I am glad I chose this subject to blog about.  I have found the whole experience of great interest and it has further increased my interest in conservation.

Climate change and reserves

I read this really interesting article yesterday about reserves and climate change.  It focussed on existing reserves and took into account future reserve selection, looking at how climate change will affect this in the next 50-100 years.  It's an interesting concept as many species within reserves will start to move north in order to escape hotter conditions within this time period.  If restricted to a reserve these species could either become extinct or simply move out of the reserve - leaving the reserve with a lower biodiversity.  The study investigated 1,200 different plant species in reserves all over Europe and modelled their change in range and distribution for the next 50 year period.  It was estimated that 6-11% of species present in each reserve would be lost from that area within this period of time.

This makes future reserve selection a difficult process as many factors need to be taken into consideration.  The solution to planning a good reserve is larger areas with good connections to other reserves.  This enables species to move northward into other reserves without extinction.

However, it is important to note that many of the species (~5%) modelled showed a complete loss of range across Europe - not just in the reserves - meaning that reserve selection and planning will not always solve the problem of species extinction.

References:
[1] Araujo et al (2004), 'Would climate change drive species out of reserves? An assessment of existing reserve-selection methods', Global Change Biology, 10, 1618-1626.

Case study: Madagascar, a biodiversity hotspot in danger

Madagascar was once connected to Africa. Since its isolation as an island, its species have evolved and now 80% of the species present are endemic. This means these species are found nowhere else on the earth and would become extinct if they could no longer thrive on the island. Madagascar is home to a large and diverse number of species, many of which are specialist species and would find it hard to adapt to changes in their environment. Climate change is putting Madagascar at risk of mass extinction.

With increasing temperatures, climate change has caused a large number of changes in the Madagascan area. The island has become warmer, drier, and at large risk of forest fires, desertification and mass extinction. Studies have shown that areas with a large number of endemic species are more vulnerable to climate change than other areas [1]. As Madagascar is situated at 20o south of the equator, species shifting to cooler climates would have to move towards the south end of the island. However, Madagascar has a highly fragmented environment, with the south end of the island experiencing the harshest conditions of wind and water scarcity [2]. This has also been made worse by the large amounts of deforestation that has occurred on the island. It has been made almost impossible in some cases for species to shift their range across the island [3].

Upward migration is still an option for some species such as reptiles, which can move to higher altitudes for a cooler climate. However, due to deforestation and changes in vegetation due to climate change, not all species have this option. [4,5].

The future of Madagascar and other biodiversity hotspot's endemic species looks bleak...although scientists are constantly calculating ways to conserve endangered species. A mass relocation of species via assisted migration could be the answer to this problem [5]. For the more specialist species, it would be harder to find an environment suited for their needs and adaptations. However, assisted migration is a very good starting point on the conservation front!

Watch MADAGASCAR (documentary) now on BBC iplayer!

References:
[1] Malcolm et al (2006), 'Global warming and extinctions of endemic species from biodiversity hotspots', Society for Conservation Biology, 20, 538-548.
[2] http://www.bbc.co.uk/iplayer/episode/b00z03pl/Madagascar_Land_of_Heat_and_Dust/
[3] Hannah et al (2008), 'Climate change adaptation for conservation in Madagascar', Global change biology, 4, 590-594.
[4] Ingram, J and T. Dawson (2005), 'Climate change impacts and vegetation response on the island of Madagascar', Philosophical transactions of the royal society, 363, 55-59.
[5] http://www.livescience.com/10575-species-relocated-prevent-extinction.html

Humans

In this blog I have looked at a large number of different species of whose ranges have shifted in the past, present, and will in the future, due to changes in climate.  However, I have not yet considered the implications of climate change on human populations and settlements.  Humans, like other species, are restricted in population ranges to climate.  For example, there are very few people who live in the highest mountain range, the hottest desert or the coldest reaches of the earth.  However, over time humans have adapted to living in these areas and small populations of humans can be found in most places on earth.  This has been advanced with the introduction of technology - for example, air conditioning means people can live in much hotter countries and stay cool.  Sea defence systems have enabled people to live on the coast in flood risk areas without needed to relocate.  However, climate change is threatening society as we know it, human populations will shift their ranges like any other species unless we can learn to adapt. [1]

Climate induced human migration can be due to a number of different things.  Climate change will not only increase the temperature globally, but will change weather patterns, increase desertification, cause sea level rise, increase water scarcity and melt areas of ice.  It could also increase conflict due to claims over water and land [2].  Many human inhabited areas will be affected by these changes, some drastically enough that populations will shift and people will migrate elsewhere.  It is predicted that by 2050, 250 million people could be displaced due to climate change induced factors (e.g. drought and flooding) [3].  Areas in Africa will become more and more arid, with water scarcity increasing - exacerbating current problems, including the spread of disease and increases in malnutrition and dehydration.  Bangladesh and other low lying areas will be greatly affected by sea level rise, resulting in a mass migration of people from the coast to higher areas.  In the tropic and subtopic areas of the globe, increased temperatures, decreased water availability and desertification will significantly reduce crop growth.  Scientists in the US are predicting an influx of 1.4 - 6.7 millions Mexicans into America by 2080 due to reductions in crop yield [4].

Luckily, for humans, migration to other areas is possible due to transportation links.  Other endangered species may face extinction if assisted migration is not possible.  However, overpopulation is also a growing issue and mass migration due to climate change will only make this worse.

References:

[1] Warren, R (2011), 'The role of interactions in a world implementing adaptation and mitigation solutions to climate change', Philosophical transactions of the Royal Society, 369. 217-241.

[2] Scheffran, J and A. Battaglini (2011), 'Climate and conflicts: the security risks of global warming', Regional Environmental Change, 11, 27-39.

[3]http://www.guardian.co.uk/environment/2007/may/14/climatechange.climatechangeenvironment

[4]http://www.bbc.co.uk/news/world-us-canada-10770674