Climate Change and Effects on Ecological Communities: Botanical Gardens as Solutions - Coursework Example

Climate Change and Effects on Ecological Communities: Botanical Gardens as Solutions 2007 Introduction Climate change has occurred for billions of years as a result of geological changes and natural ‘greenhouse effect’, a term coined by the French mathematician Fourier in 1827 (Stern Review, 2006). Gases like carbon dioxide and water vapor trap solar radiation that would otherwise radiate back to the atmosphere. It is estimated that natural greenhouse effect warms the earth by 30oC more than what the temperature would otherwise be and thus makes it habitable (Stern Review, 2006). In addition to this, human induced climate change as a result of increased emission of gases like carbon dioxide has resulted in global warming. The Intergovernmental Panel on Climate Change (IPCC) forecasts that carbon dioxide concentration may increase from 380 ppm now to 540-970 ppm in 2010 because of human development, changes in ecosystem resulting from shifts in land and energy use patterns, industrialization and other economic and livelihood factors (Stern Review, 2006). The higher concentration of carbon dioxide in turn would result in raising the average global temperature by 1.4 – 5.8oC and the sea level by 9-88cm by 2010 depending upon the intensity of various factors mentioned above (Stern Review, 2006). Rapid climate change by 2-3oC will have severe effects on the biodiversity on the earth, damaging the environment even further. This paper will study the effects of human-induced climate change on the plant and ecological communities. Rise in surface temperature as a result of global warming will not only change the geographic distribution of many species of wildlife but also affect the reproductive rates of some species, ultimately resulting in a reduced biodiversity. In order to combat this problem, growing and harvesting different species of plants in the botanical gardens, conservation and diversification of plant species may be achieved. The second part of the paper will survey attempts of some botanical gardens in doing this. Plant Migration and climate clange Migration of plant communities towards the closest poles has happened since the prehistoric times through dispersal of seeds by birds, mammals, wind and water. Both natural and human-induced climate change leads to seed dispersal faster than it can facilitate plant migration. Also, some of the species may become extinct when thrown to unfavorable geographic conditions (Pitelka, 1997). Evidence of natural plant migration is found from the fossil record of pollen accumulation in lake sediments at various sites. It was found that some tree species migrated northward in response to climate change after the Northern Glaciers retreated in the early years of the Halocen epoch that began 10,000 years ago (Pitelka, 1997). Plant migration, however, does not happen in its entirety even when only the natural dispersal mechanism is under way. On the other hand, compositions of new plant species form and develop. If plant migration had happened only through natural migration, it would perhaps been slowed down with human fragmentation of the habitat. Instead, some species that humans deliberately move – like timber or extinct species that are carried to different places – do so faster. It has been seen that plant migration and reproduction occurs faster in the northern temperate latitudes where warming as a result of greenhouse emission is higher and that it is unrelated to physical barriers like Great Lakes, North and the Baltic Seas. In addition to the seed dispersal by birds and mammals, it is thought that occasional long jumps carry seeds faster and to outlier positions resulting in foci developing when the habitat becomes favorable. Such plant communities, like the migration of Norway Spruce across Europe during the Halocen years and in Sweden 3,000 years ago, cannot be explained by migration of windborne pollen alone. Studies have inferred that the fast seed dispersal is explained by climate change and global warming that induces the long jumps and outliers (Pitelka, 1997). Effect of climate change on species distribution has been studied in the sub-Saharan region of Africa. Climate models generated for 2025, 2055 and 2085 by the Hadley Center through a genetic algorithm indicates the possibilities of major shifts in species. Nearly 81-97 percent of the 5197 African plant species will have reduced suitable areas as a result of decrease in size or shift of location. Many of the species will lose area totally by 2085 (Colin et al). By the late 21st century, more than half of the 1,350 European plant species face vulnerability to extinction by 2080. The extent of loss and turnover of species depends on the degree of change in climate variables like moisture and temperature. The greatest change is anticipated in between the Mediterranean and Siberian regions (Thuiller et al, 2005). Some plant communities are more vulnerable to climate change than others. For example, regional warming may affect Norway spruce that grows as timber in Sweden (Pitelka, 1997). Even the Amazon rainforests may be destroyed as a result of global warming, turning it into desert land, ruining the livelihood of thousands of people. Many other regions may also turn into deserts with the loss of forestland. It is projected that a 2oC increase in temperature will result in a 24 percent destruction of trees in the Central Brazil Savannas. Species might become extinct in Mexico, Bolivia, Chile and Argentina. In the region, the Caribbean, the Tropical Andes and the Atlantic forests are most likely to face an adverse effect of biodiversity. Studies predict that wildlife species will change in composition rather than becoming extinct totally (Milius, 2002). Land use and vegetation patterns may change as a result of climate change which in turn will have a snowballing effect on the climate. Chen et al (2007) have predicted that climate changes will alter the land use pattern in the United States, thereby changing the population habitat and hence anthropogenic air pollutants in certain regions. This will significantly affect the lower troposphere and the secondary pollutants in the air. Through a numerical modeling exercise on US air quality for the period 1990-2000 and stimulating for 2045-2050, the authors predict that anthropogenic, fire and biogenic emissions will increase because of land use and vegetation pattern changes. Natural and human-induced disturbances in the ecosystem may occur as a result of climate change. Dale (2001) studied the effect of such disturbances on the forests of the United States. Each disturbance like fire, drought, flood, ice storms, landslides, insect and pathogen outbreaks, hurricanes and introduced species affect forests differently. While some disturbances may cause large-scale mortality, others may change community compositions. Natural disturbances interact with human-induced ones like air pollution and land-use change resulting in a complicated process of vegetation change. The vegetation usually is resistant to natural disturbances like droughts. However, if human-induced climate change results in large-scale change of disturbances, it might lead to species mortality. Climate change adaptation strategies require vulnerability assessment and risk management. Forest ecosystems and species adapt to climate change automatically and society needs to adapt itself to such changes in the forests (Spittlehouse, 2005). Anthropogenic changes in the environment, like scarcity of plant resources and suitable habitat, high densities of predators and pathogens, physical disturbances, temperature and climate change, aggravated by human action, as also human fragmentation of vegetation affect biodiversity and plant communities. It results in vacant niches and domination of weedier varieties that are poor competitors and faster dispersers. The extent of such anthropogenic effect depends on the composition of changes and their magnitude (Tilman and Lehman, 2001). Many plant species, however, kept pace with climate change and remained static communities. Besides the long jump-outlier processes, contemporary plant invasions have also happened through human efforts. For example, the B. Tectorum arrived in the 1880s in the intermountain West, bounded by the Rocky Mountains on one side and the Cascade-Sierra Nevada ranges through agricultural seed contaminations. For 20 years, despite the growth of 50 foci, the grass remained small. Over the next 10 years, the grass species dominated the entire region. Similar plant invasion has happened all over the northern latitudes through the introduction of parasites and predators in insecticides. The natural dispersal mechanism is also bypassed and superceded by human cultivation activities that plant seeds thousands of kilometers away from the native habitat. Plant communities are also disturbed through fire, flood, windstorms, burrowing and grazing. Through introduction of livestock and through agricultural, horticultural and landscaping practices, man has assisted plant invasion and migration (Pitelka, 1997). The Impact of Botanical Gardens One way to overcome the issue of plant migration and loss of biodiversity is to grow species in botanical gardens that may serve as official depositories of endangered species. The first botanical garden was perhaps built in the Hanging Gardens of Babylon by Nebuchadnezzar in 570 BC (Biodiversity International). Research on biodiversity began by the 16th century, particularly in the study of taxonomy and aromatic and medicinal plants. At present, there are more than 200 botanical gardens in 100 countries, playing crucial roles in conservation programs. They have in situ projects like field genebank as well as ex situ projects like seed genebank or both. The Royal Botanical Gardens is trying to restore the aquatic habitat of the Cootes Paradise marsh and lower Grindstone Creek that flow into Hamilton Harbor in western lake Ontario. The Garden has a number of restoration projects, including the Project Paradise, the largest conservation project in North America. The marshes in Cootes Paradise and Grindstone Creek has faced human induced stressors provided plenty of fishing and hunting opportunities for the settlers since the 1800s. Further, by the end of the 19th century, exotic plant species like purple loosestrife and reed manna grass invaded the marshes and began to compete with native plants. By the 1930s, plant diversity in the marshes fell permanently by 15 percent and by 1985, 85 percent of the original plant cover in the area was lost. In 1986, the Hamilton Harbor Remedial Plan was initiated to rectify the environmental degradation of the marshes (rbg.org). All countries partnering the Convention of Biological Diversity held at Rio in 1992 agreed to use biological resources for scientific and environmental uses for the purpose of maintaining biodiversity and sustainable development. The University of British Columbia (UBC) Botanical Garden and Center for Plant Research conducts research in plant diversity and maintains living plants ex situ or off site for conserving genetic resources. It also maintains in its collection Japanese and British Columbian plants (ubcbotanicalgarden.org). Seed banking is one way of ex situ or off-site technique that is most popular for conserving genetic resources of rare plant species. Storing seeds ex situ in the botanical garden is an inexpensive way of conserving biodiversity. However, storing seeds is risky since it may well turn out to be ultimately inadequate hence it is used as one of the methods for conserving biodiversity. The Berry Seed Bank was the first to set up a seed bank in North America in 1983 to conserve the rare flora of the Pacific Northwest (Berrybot). The seed bank at the Chicago Botanical Garden is part of the Seeds of Success (SOS) program of the Plant Conservation Alliance developed by the Royal Botanical Garden that aims to collect seeds from 10 percent of the world’s flora, constituted by 24,000 species, by 2010. The Chicago Botanical Plant plans to collect 1,500 prairie species as the tallgrass prairie is one of the most endangered species that now cover only 0.01 percent of the original cover (chicagobotanic.org). Although seed banking is the most popular technique for conservation of plant species, there are many areas like in Africa and the Middle East where neither facilities nor knowledge about seed banking exist. The Key Millennium Seed Bank Project, that targets conservation of 10 percent of the earth’s plants species by 2010, has undertaken a massive seed collection program in these areas. The team of seed collectors also captures detailed information of the native habitat, ecology and state of plant population. The seeds are dried and stored at the National Plant Genetic Resource Center in the UK. The seeds are reintroduced under different conditions. For example, 40 species identified to be suitable for village communities in Botswana are being developed in a nursery there to test for suitability for use by village-based industries (Smith). The Center for Plant Conservation set up in 1985 in the Missourie Botanical Garden as the consortium of all botanical gardens for conserving rare plant species. Seeds are collected, cleaned and stored mostly in frozen conditions in the seed banks. Orthodox seeds can sustain extremely low temperatures and can be frozen for long. But, certain seeds like the tropical fruits or acorns cannot be frozen since they do not sustain freezing. The moisture level and the storage temperature determine how long the seeds can be stored (bgci.org). Gene banks conserve genetic resources, for which storing and monitoring of quality is crucial. The effectiveness of the reproduction or regeneration of the genetic resource is the vital function of the gene bank that use in vitro storage and cryopreservation to conserve recalcitrant seeds or species that are vegetatively propagated (Biodiversity International). The cryopreservation technique stores living tissues at extremely low temperatures in liquid nitrogen, facilitating long term storage. The Botanical Gardens of Adelaide Seed Conservation Center uses ex situ methods integrated with in situ techniques for plant conservation. It collects endangered plant species from South Australia and develops germination and storage protocols for each species. The center aims to collect at the most 20 percent of the native seed so that there is no long term effect of the seed collection. However, sufficient seed is collected to enable testing and germination that is conducted in a temperature-monitored atmosphere. The center also undertakes alternate conservation techniques like recalcitrant of long-term storage, tissue culture based propagation or embryo culture (Seed Conservation Center). Flora translocation through seeds, cuttings or propagated seedlings is another way of conserving plant species in cases where survival of the species is nearly impossible without intervention. This process of conservation may be undertaken by many methods, like augmenting, planting more trees where the species already exists, reintroducing the species where it used to occur but now has become extinct, introducing new species in areas that are within the distribution range and where habitats are similar or are favorable (Naturebase). Conclusion Thus, climate change and global warming is enhancing migration of plant communities faster than can be sustained. Human-induced climate change through greenhouse gas emission and air pollution has altered plant biodiversity through disturbances in the ecosystem that ruin a large number of plant species or alter the composition. This not only results in loss of biodiversity but also aggravates the problem of climate change through loss of vegetation, thereby resulting in increased temperature, soil erosion and raising of sea levels. To mitigate the spiraling effects of climate change and loss of biodiversity, various conservation techniques – both in situ and ex situ – have been adopted. In particular, ex situ methods like seed banks and gene banks in botanical gardens have been found to be useful in conserving rare plant species. But the effectiveness of such techniques depends on the efficiency in cryopreservation, monitoring and regeneration of seeds. Works Cited Intergovernmental Panel of Climate Change (IPCC). Climate Change: Third Assessment Report, 2001. Retrieved on January 25, 2007 from http://www.grida.no/climate/ipcc_tar/ Milius, S, Climate upsets: big model predicts many new neighbors - how global climate change affects animal communities, Science News, April 13, 2002. Retrieved on January 24, 2007 from http://www.findarticles.com/p/articles/mi_m1200/is_15_161/ai_85175718 Stern Reviews of the Economics of Climate Change. Technical Annex: The Science of Climate Change, 2006. Retrieved from January 24, 2007 from http://www.hm-treasury.gov.uk/media/695/0E/Oxonia_Technical_Annex_FINAL.pdf Pitelka, Louis F, Plant Migration and Climate Change, American Scientist 85.5, 1997 Tilman, David, and Clarence Lehman, Human-Caused Environmental Change: Impacts on Plant Diversity and Evolution, Proceedings of National Academy of Sciences, 98, 2001: 5433-5440 http://www.anbg.gov.au/bibliography/climate-change.html Colin, J McClean, et al, African Plant Diversity and Climate Change, Annals of the Missouri Botanical Garden: Vol. 92, No. 2, pp. 139 152.http://apt.allenpress.com/aptonline/?request=get-abstract&issn=0026 6493&volume=092&issue=02&page=0139 Thuiller, Wilfried, et al, Climate change threats to plant diversity in Europe, Proceeding of the National Academy of Sciences of the United States of America, May 26, 2005, http://www.pnas.org/cgi/content/full/102/23/8245 Dale, Virginia et al., Climate Change and Forest Disturbances, Bioscience, September 2001, Vo 51 No 9 Chen, J et al (2007), Impact of Climate Change on U.S Air Quality Using Multi-scale Modeling with the MM5/SMOKE/CMAQ System. Undated. Retrieved on January 25, from http://ams.confex.com/ams/pdfpapers/74084.pdf Spittlehouse, David.L, Adaptation to Climate Change in Forestry, http://www.for.gov.bc.ca/hre/pubs/docs/Spittlehouse2005_Species@Risk.pdf Botanical Garden Consortium International (BGCI), http://www.bgci.org/worldwide/article/0185/ The Berry Botanic Garden, http://www.berrybot.org/pubs/ar_ssfuture.html Biodiversity International, http://www.bioversityinternational.org/Themes/Genebanks/index.asp Chicago Botanical Garden, http://www.chicagobotanic.org/research/staff/havens.php Nature Base, Nature and Biodiversity, http://www.naturebase.net/content/view/2598/1332/ Seed Conservation Center, http://www.environment.sa.gov.au/botanicgardens/seed_conservation.html Smith, Paul, Seeds for the Future, Plant Talk, http://www.plant-talk.org/stories/43kewmsb.html Read More

Effect of climate change on species distribution has been studied in the sub-Saharan region of Africa. Climate models generated for 2025, 2055 and 2085 by the Hadley Center through a genetic algorithm indicates the possibilities of major shifts in species. Nearly 81-97 percent of the 5197 African plant species will have reduced suitable areas as a result of decrease in size or shift of location. Many of the species will lose area totally by 2085 (Colin et al). By the late 21st century, more than half of the 1,350 European plant species face vulnerability to extinction by 2080.

The extent of loss and turnover of species depends on the degree of change in climate variables like moisture and temperature. The greatest change is anticipated in between the Mediterranean and Siberian regions (Thuiller et al, 2005). Some plant communities are more vulnerable to climate change than others. For example, regional warming may affect Norway spruce that grows as timber in Sweden (Pitelka, 1997). Even the Amazon rainforests may be destroyed as a result of global warming, turning it into desert land, ruining the livelihood of thousands of people.

Many other regions may also turn into deserts with the loss of forestland. It is projected that a 2oC increase in temperature will result in a 24 percent destruction of trees in the Central Brazil Savannas. Species might become extinct in Mexico, Bolivia, Chile and Argentina. In the region, the Caribbean, the Tropical Andes and the Atlantic forests are most likely to face an adverse effect of biodiversity. Studies predict that wildlife species will change in composition rather than becoming extinct totally (Milius, 2002).

Land use and vegetation patterns may change as a result of climate change which in turn will have a snowballing effect on the climate. Chen et al (2007) have predicted that climate changes will alter the land use pattern in the United States, thereby changing the population habitat and hence anthropogenic air pollutants in certain regions. This will significantly affect the lower troposphere and the secondary pollutants in the air. Through a numerical modeling exercise on US air quality for the period 1990-2000 and stimulating for 2045-2050, the authors predict that anthropogenic, fire and biogenic emissions will increase because of land use and vegetation pattern changes.

Natural and human-induced disturbances in the ecosystem may occur as a result of climate change. Dale (2001) studied the effect of such disturbances on the forests of the United States. Each disturbance like fire, drought, flood, ice storms, landslides, insect and pathogen outbreaks, hurricanes and introduced species affect forests differently. While some disturbances may cause large-scale mortality, others may change community compositions. Natural disturbances interact with human-induced ones like air pollution and land-use change resulting in a complicated process of vegetation change.

The vegetation usually is resistant to natural disturbances like droughts. However, if human-induced climate change results in large-scale change of disturbances, it might lead to species mortality. Climate change adaptation strategies require vulnerability assessment and risk management. Forest ecosystems and species adapt to climate change automatically and society needs to adapt itself to such changes in the forests (Spittlehouse, 2005). Anthropogenic changes in the environment, like scarcity of plant resources and suitable habitat, high densities of predators and pathogens, physical disturbances, temperature and climate change, aggravated by human action, as also human fragmentation of vegetation affect biodiversity and plant communities.

It results in vacant niches and domination of weedier varieties that are poor competitors and faster dispersers. The extent of such anthropogenic effect depends on the composition of changes and their magnitude (Tilman and Lehman, 2001). Many plant species, however, kept pace with climate change and remained static communities.

Read More