Set-aside- a saviour? (2)

Although not the primary intention, set aside has had a significant impact on biodiversity. This is well known despite a lack in comprehensive UK study. The UK Biodiversity Action Plan (UKBAP) identified cereal field margins, in which set aside can be included, as priority habitats and aimed to increase the number of hectares to 15 000ha by 2010, although this was met in 2008  (Hodge et al, 2006).

An integrated assessment by Firbank et al,  assessed environmental impacts of the scheme. They first carried out botanical surveys to assess the development of vegetation on set aside land. This involved analysing a single field using six nested quadrants on 100 farms with rotational set aside,  and one field from 100 farms with non rotational set aside. The same process was also used to test for aphids, slugs and deadhearts (the visible affect of damage by insect pests). Surveys of breeding birds were carried out using a territory mapping method on 92 farms in 1996 and 63 in 1997. Farmers were also given questionnaires and asked to note observations during the study.(Firbank et al, 2003)

A mean of 12 plant taxa were recorded on rotational set aside, and the plant species were fairly similar at each site although one nationally rare plant, Chrysanthemum segetum L was recorded. There was also no significant increase in weeds next to crops, which had been a concern for farmers following the introduction of the scheme. On non rotational set aside, in which the land is left alone for a number of years, plant species richness was great on natural regeneration than on sown set aside, 26.5 and 20.0 per site respectively. However, there was little sign these areas were developing into sites of conservation value although older sites did have more perennial species such as Fistula pratences typical of grasslands which are of conservation value. As part of the questionnaire farmers were asked to note increases in wildflowers. 20% of farmers with rotational set aside and 51% with non rotational set aside reported an increase. According to farmers, levels of crop disease was not affected by set aside with 85% noting that the risk of fungal disease on adjacent crops was unchanged.(Firbank et al, 2003).  

Slugs were present throughout the year and were observed on 60-80% of set aside and adjacent cropped sites in the autumn 1995 but fell to 10-40% of sites the following summer. During autumn 1995, 9% of non-rotational set aside sites were infected with aphids. The proportion of cropped fields with aphids rose to 33% of sites in 1996 and 54% in 1997 although the proportion of set aside fields with aphids remained below 10%. The trend in dead harts appears similar as they occurred in 7-24% of sites in cropped fields and between 0-10% in set aside fields. 80% of farmers reported no change in numbers of these insect pests next to set aside.(Firbank et al, 2003) 

Skylark

The territory mapping method reported that rotational set aside supported nine times the density of birds on crops compared with seven times in non rotational sown grassland set aside. Vegetation structure did effect bird numbers and species type. For example, further studies looked at bird species in different areas of the field. Game birds, typically seed eaters, preferred bare ground with the blackbird (Turdus merula L), song thrush (Turdus philomelos ) and pheasant (Phasianus colchicus L.) preferring the outer 5m of the field. Goldfinch (Carduelis carduelis L.) , greenfinch (C. chloris L.)  skylark (Alauda arvensis) and the combined group of wading birds increasing towards the field centre (Henderson et al, 2000). Maintaining a variety of habitat structures, management techniques and plant and insect diversity therefore benefits overall bird diversity and species richness. Overall, 47% of farmers with rotational set aside and 69% of farmers with non rotational set aside reported an increase in numbers (Firbank et al, 2003) .

From these studies it is clear that the fears farmer held, that set aside would increase insect pests and crop disease, did not occur to a great extent in the areas under study. Plant and bird diversity increased significantly, particularly in non rotational set aside where the land was left to naturally progress. Maintaining a variety of habitats, for example some areas left as stubble, is the ideal method for maximum diversity. However, the scheme was suspended in 2008/9 due to public pressure and those leaving land as set aside were no longer entitled to payments. This was replaced in 2010 by alternative policies to promote biodiversity conservation as farmers were required to manage a small percentage of land for environmental purposes, as opposed to just leaving land alone (HMRC, 2014). Furthermore, the 900 million payment scheme entitled the ‘Wild Pollinator and Farm Wildlife Package’ announced in 2014 will hope to carry on what the set aside scheme established, providing space for wildlife for the benefit of all (Trust, 2014). 

Sources: 

Firbank, L. G.et al. 2003. Agronomic and ecological costs and benefits of set aside in England. Agriculture, ecosystems and environment. Vol. 95 (1). pp73-85.  

Henderson, I. et al. 2000. The relative abundance of birds on set-aside and neighbouring fields in summer. Journal of applied ecology. Vol. 37 (2). pp. 335–347.

HMRC. 2014. IHTM24064 - Agricultural purposes: Set-aside scheme. [online]. Available at: http://www.hmrc.gov.uk/manuals/ihtmanual/ihtm24064.htm. [Accessed 30.12.14]

Hodge, I. et al. 2006. Project to assess future options for set aside. University of Cambridge. [online]. Available at: http://archive.defra.gov.uk/evidence/economics/foodfarm/evaluation/futuresetaside/Fullreport.pdf [Accessed 30.12.14]

Trust, E. 2014. Environment and the Rural Economy.   [transcript]. 4.11.2014. Available at:https://www.gov.uk/government/speeches/elizabeth-truss-speech-on-the-environment-and-the-rural-economy [Accessed: 31.12.2014]

Set-aside- a saviour? (1)

Set aside is probably the most well known and frequently debated management technique in european agriculture. It was introduced by the European Community as part of the Common Agricultural Policy in 1988 to reduce surpluses and counteract environmental problems as result of intensification of agriculture. In 1995/6, it was estimated that 500 000 ha were designated as set aside, equivalent to 11% arable land although the scheme was suspended in 2008 (Firbank, 1998)(HMRC, 2014).  

Modern farming has always been a source if pollutants, particularly nitrates in surface and groundwater and phosphates in surface water from pesticides, sediments and eutrophication. In 2006 a DEFRA funded study analysed the affect of the set aside scheme on levels of certain pollutants. By changing land use, set-aside can reduce the levels of diffuse pollutants entering surface and ground waters as significantly less is sprayed, as demonstrated in the table below.(DEFRA, 2007) 

Fig. 1- Areas treated with different kinds of pesticides as a percentage of area grown. Treated areas above 100% have been sprayed more than once (DEFRA, 2007). 

The Environment Agency as part of the Water Framework Directive found pollution from nitrate leaching was a major issue in arable areas of the country with East Anglia, Lincolnshire and Humberside worst affected. The study compared nitrate losses for arable systems in clay or sandy soils in dry and wet years with or without the application of organic manure as shown in the table below. The table suggests that the removal of set aside and the reintroduction of arable practice will increase nitrate output by 23-47kg per ha per year for non manure systems (IGER, 2005). When levels are already high, such as the Humberside, additional measures would need to be introduced that may result in increased public expenditure (Hodge et al, 2006). 

Fig.2- Nitrogen losses from different arable systems with mitigation measures (IGER, 2005). 

A cost benefit analysis was carried out based solely on the area understudy. This suggested that in the cases where additional measures were required, the gain would be the value of net output on 21 000ha plus the value of the output less mitigation costs on 157 000ha. This therefore suggests that in the case of nitrogen leaching, it makes sense to convert set aside. However, the study is simplistic and  fails to consider measures to address loss of phosphates and other pollutants along side other risks. Similar results were also found for studies looking at phosphorus levels. Furthermore, evidence also suggests reversion of set aside increased N2O, a greenhouse gas, as a result of an increase in field operations(Hodge et al, 2006)(DEFRA, 2007). 

Although set aside does reduce leaching of nitrates and phosphates with slight impact on greenhouse gas emissions, it appears that these impacts do not outweigh the economic impacts of reversion to working land. However, there has been little research on combined pollutants or the impact of set aside as a buffer zone. In addition, the following post will assess the impacts of set aside on plant, vertebrate and invertebrate biodiversity to further assess the schemes significance. 

Sources: 

DEFRA. 2007. Change in the area and distribution of set-aside in England and its environmental impact. [online]. Available at: http://archive.defra.gov.uk/evidence/statistics/foodfarm/enviro/observatory/research/documents/observatory08.pdf [Accessed 30.12.14] 

Firbank, L.  1998. Agronomic and environmental evaluation of set-aside under the EC Arable Area Payments Scheme, vols. 1–4. Institute of Terrestrial Ecology/Ministry of Agriculture, Fisheries and Food, London.

HMRC. 2014. IHTM24064 - Agricultural purposes: Set-aside scheme. [online]. Available at: http://www.hmrc.gov.uk/manuals/ihtmanual/ihtm24064.htm. [Accessed 30.12.14]

Hodge, I. et al. 2006. Project to assess future options for set aside. University of Cambridge. [online]. Available at: http://archive.defra.gov.uk/evidence/economics/foodfarm/evaluation/futuresetaside/Fullreport.pdf [Accessed 30.12.14] 

IGER. 2005. Cost Curve of nitrate mitigation options NT2511. Report for Defra. Institute of

Grassland and Environmental Research. 

Agro-ecosystems

In agricultural systems biodiversity perform a number of ecosystem services including nutrient recycling, micro climate control, regulation of the local hydrological cycle and pest control. The persistence and health of these services depends on the maintenance of diversity, without which constant human intervention is required (Altieri, 1994).

As a result of expanding human populations, globalisation, and the intensification of agriculture there is increased reliance on a small number of crop species. Across the 1440 million ha of presently cultivated land, only 70 plant species are grown (Perry, 1994). There is also limited genetic variability. For example in the US 72% of the area planted with potato consist of just four species increasing vulnerability to disease and pests (National Academy of Sciences, 1972). 

In agro-ecosystems the degree of biodiversity depends on the diversity of vegetation within and around the agro-ecosystem, the permanence of various crops, the intensity of management and extent of the isolation of the system (Southwood and Way, 1970). As a result, biodiversity can be grouped into productive biota or crops and livestock deliberately selected, resource biota or organisms that contribute e.g. pollinators and pest controllers such as Apis mellifera,the common honeybee, and finally destructive biota such as Phytophthora infestans or potato blight. To promote the required ecosystem services, it is important to determine the best practices that maximise productive and resource biota (Altieri, 1999). 

In 2014 the INSPIA project was initiated, bringing together the European Conservation Agriculture Federation, the Institute for Sustainable Agriculture and the European Crop Protection Association. The project aims to raise awareness about the value of Best Management Practices (BMPs) to both biodiversity and agricultural productivity and how to implement them. These BMPs include the use of minimum soil disturbance practices. This favours the proliferation of  Lumbricus terrestris, the common earthworm, improving soil aeration and water infiltration. They also include the implementation of field margins or buffer strips. These areas enhance agro-biodiversity by providing habitats for birds, other pollinators and soil fauna. They also prevent soil erosion, the transfer of agricultural pollutants from crop land to non crop land and slow runoff.  As it stands, the project promotes 15 BMPs, many of these drawing on more traditional agriculture practices (INSPIA, 2014).

Sources:

Altieri, M. 1994. Biodiversity and Pest Management in Agroecosystems. Haworth Press: New York. p185 

Altieri, M. 1999. Th ecological role of biodiversity in agro-ecosystems. Agriculture, Ecosystems and Environment. vol 74. pp19–31. 

INSPIA. 2014. European Index for sustainable productive agriculture. [online]. Available at: http://www.inspia-europe.eu/ [accessed 28.12.14]. 

National Academy of Sciences. 1972. Genetic vulnerability of major crops. NAS: Washington. p307 

Perry, D.1994. Forest Ecosystems. Johns Hopkins University Press: Baltimore. p649.

Southwood, R and Way, M.J. 1970. Ecological background to pest management. In: Rabb, R and Guthrie, F.E. (Eds.). Concepts of Pest Management. North Carolina State University: Raleigh.  pp. 6–29. 

Brazil is home to the largest extent of tropical forests in the world but with a yearly annual deforestation rate of 1.8 to 2.0 million hectares between 1995 and 2000 (Ruiz-Pérez, 2005). Extractive reserves, drawing on traditional land use techniques are thought to be an innovative approach to land use; protecting biodiversity, promoting development and preserving traditional ways of life (Barnes,1999).  

Rubber tapping is considered a method for sustainable development as it incurs very little damage to the forest as only a small amount of biomass os removed from select trees (Barnes, 1999). During the 1980s the state of Acre in western Brazil was the site of protest led by the rubber tapper Chico Mendes against environmentally destructive national development plans. His assassination and subsequent international condemnation led to the establishment of extractive reserves and the 1999 Chico Mendes Law (IUCN, 2008). The law provided subsides for rubber tappers registered with the executive secretary of forest and extractivism and the state government. These reserves are organised into seringais, a traditional rubber estates, surrounding colocação, a rubber tapping unit containing a family home, agricultural plot and rubber trees. These were divided up according to the number of rubber trail units, typically three each at approximately 100-125ha her unit. Each colocação are members of the national council of rubber tappers who distribute the subsides (Vadjunec, 2009. Each tapper receives US$0.20 for every kilogram of rubber extracted and between 1999 and 2002.  the total paid to rubbers increased from R$305,000 to $1600000 (Barnes, 1999). 

The reserves and law would be considered successful if they promoted the redistribution of resources and participation resulting in the strengthening of social capital. This refers to the networks of relationships and values binding groups together for collective action. Originally, the social structure of rubber economy was vertical; patron-clientage and from estate owners or intermediary merchants downwards ensuring the workers were trapped in cycles of poverty and dependence. The protest and subsequent reserves attempted to democratise and unionise the workers. Although this did improve conditions and social capital in some instances, it also resulted in additional conflict amongst the rubber tappers. For example, rubber tapper groups better organised and loyal to the unions are likely to be favoured and this undermines improvements to social capital and collective resource governance (Hall, 2004). 

The Chico Mendes Law and the subsides it provides was an attempt to reboot the rubber tapping industry as since the mid 1990’s it became apparent that rubber tapping and nut harvesting alone  were unlikely to generate adequate levels of income. Between 1992 and 2002, a total of R$1.2 million was paid in subsides to rubber tapper communities with the state receiving 70% back in tax. Furthermore, the total paid to rubbers increased from R$305 000 to $1600000 (Barnes,1999). Although the rubber tapping economy has seen a boost, it is unclear whether this has led to poverty alleviation, partly due to the social difficulties discussed above. Furthermore, many families have adapted, increasingly relying on beans instead of rubber as a key commodity with developments also made in rubber processing plants and livestock (Ruiz-Perez, 2005). 

Since the reserves were implemented, 12 000 km2 of rainforest have been designated protected areas (Barnes, 1999). Furthermore, studies by Vandjunec et al among others have assessed the impact of extractive reserves on forest preservation. They selected two sites of similar geographical characteristics and in close proximity linked to the same municipality. However, one was increasingly focusing on non timber forest products and the other cattle production. Satellite imagery and measures of diversity including the Margalef index were calculated to compare species richness, abundance, composition and distribution of trees. By 2003, the cattle community had cut 8.26% of its forest with an average annual rate of 0.38%/year across the 18 year study. The rubber tapping community however had only cut 3.835 of its forest with an average annual deforestation rate of 0.20%/year.  However, when comparing species richness, the cattle ranching community scored greater (Vandjunec, 2004). It is unadvisable to extrapolate out from this study although it suggests that although rubber tapping reserves may preserve forests from deforestation, they may result in some damage to species richness and biodiversity. 

On paper extractive reserves seem like the ideal form of sustainable development with wide reaching economic, social and environmental benefits. However, the nature of these problems are complex and relying on one management technique too naive particularly as the benefits are so uncertain. Further studies are needed on the specific effects of various types of non timber forest products along with dominant production such as logging and cattle ranching that also look at the impacts on forest structure and composition not just area preserved. Furthermore, to generate conclusive evidence these studies are needed on local and national scales over long time periods.  As it stands, these reserves and subside programmes are not viable on very large scales. Further mechanisms need implementing and testing if we are to slow deforestation and the rates of biodiversity loss whilst still supporting local communities. 

Sources:

Barnes, A. et al. 1999. Chico Mendes Law. USAID. [online]. Available at: http://www.cbd.int/financial/pes/brazil-pesrubbertappers.pdf. [Accessed 22.12.14]. 

Hall, A. 2004. Extractive Reserves: Building Natural Assets in the Brazilian Rainforest. Political Economy Research Institute. [online]. Available at: http://scholarworks.umass.edu/cgi/viewcontent.cgi?article=1060&context=peri_workingpapers [Accessed 22.12.14]

IUCN. 2008. Supporting local forest use in Amazonian Brazil: The Chico Mendes Extractive Reserve. [online]. Available at: http://cmsdata.iucn.org/downloads/rubber_story.pdf [Accessed 22.12.14]

Ruiz-Pérez, M. et al. 2005. Conservation and Development in Amazonian

Extractive Reserves: The Case of Alto Jurua´. Ambio. Vol. 34.(3). pp 218-223. 

Vadjunec, J. M., and D. Rocheleau. 2009. Beyond forest cover: land use and biodiversity in rubber trail forests of the Chico Mendes Extractive Reserve. Ecology and Society 14(2): 29. [online]. Available at: http://www.ecologyandsociety.org/vol14/iss2/art29/ [Accessed 22.12.14]

Biological and Cultural Diversity

Biological and cultural diversity are highly interconnected and mutually dependent. This extends beyond the acknowledgement that humans perceive and act upon nature in distinct ways. Certain cultural practices depend upon elements of biodiversity for their expression and existence and in many cases biodiversity is developed, maintained and managed by cultural groups (Unesco, 2003). This relationship extends from the development of human belief systems and worldview to management, knowledge, norms and institutions. 

Human belief systems and worldview is shaped by relationships to the natural world. The green theory of value developed in 1992 suggests that all humans need some sense and pattern in their lives and nature provides the backdrop for this by setting human lives in larger contexts (Goodin, 1992). This is particularly relevant to the 4 500 indigenous communities, many of which are located in areas of high biodiversity (Unesco, 2003). Different faith groups also represent the different relationships human have with nature. Judaism, Christianity and Islam, all arising from the Middle East, speak of human’s ‘dominion’ over nature, whilst Buddhism and Hinduism all speak of the inter- relationships between the two factors (Dudley, 2006).

Managing nature has also shaped human culture. This may be through livelihoods, practices and resource management systems. As a result, in many cases near pristine environments are often sacred sites such as the Tabul in Papa New Guinea (Pretty, 2009). Due to the extent of population growth and migration around the globe, human manipulation of the landscape is so great scientists now debate whether we have entered a new epoch, the Anthropocene (Crutzen, 2007). 

Knowledge across the word is dynamic and shaped by the natural world. This understanding is transferred through cultural mechanisms such as stories and observations as individuals travel. Local knowledge is central to the sustainable management of resources as well as species requirements and ecosystem dynamics. Medicines generated from natural products is an excellent example of this as discussed in an early blog post. This local knowledge often results in norms and regulations such as rules on resource extraction and land use zoning. As this is highly contextual, these norms and regulations and subsequent institutions surrounding them are highly diverse.(Pretty, 2009)(Stevens, 1997). 

Sources:

Crutzen, P. et al. 2007. The  Anthropocene: are humans now overwhelming the great forces of nature?.Ambio. Vol. 36(8).pp 614-621

Dudley, N. et al.  2006. Beyond belief: Linking faiths and protected areas to support biodiversity conservation. WWF and Alliance of Religions and Conservation. Switzerland and

Manchester: Gland. 

Goodin, R.E. 1992. Green political theory. Cambridge: Polity Press.

Pretty, J. 2009. The Intersections of Biological Diversity and Cultural Diversity:

Towards Integration.Conservation and Society 7(2): 100-112. 

Stevens, S. 1997. Conservation through cultural survival: Indigenous

peoples and protected areas. Washington, DC: Island Press.

Unesco, 2003. Cultural diversity and biodiversity for sustainable development.  [pdf]. Available at: http://unesdoc.unesco.org/images/0013/001322/132262e.pdf [Accessed: 19.12.14]. 

Easter Island Emergency

Small islands, as a result of their size, remoteness and high levels of endemism are vulnerable to environmental changes and frequently used as an environmental morality tale. For example, the population collapse of Rapa Nui, or Easter Island, has been well documented as a parable for the dangers of environmental destruction.

Easter island, one of the worlds most isolated inhabited island in the southeastern pacific ocean was first settled by Polynesian people in the first millennium and a thriving culture developed. However, as a result of a multitude of factors discussed below, by 1772 their population had crashed significantly and was reduced down to 11 by 1877 (Peiser, 2005). 

Literature including ‘collapse’ by Jared Diamon takes an environmental determinist approach to the catastrophe. The island was covered in subtropical broadleaf forests, in particular the now extinct endemic palm Paschalococos disperta.  Supposedly, a growing population overexploited the environment, deforesting the island, using the palms for agriculture, canoe building, fire settling and the transport of the famous Moai statues. This process worsened as a result of the introduction of the Polynesian rat, as the palm fruit and nut acted as a primary food source. The pressures that led to forest removal led to competition between islanders which quickly spiralled into chaos- triggering war, famine and cultural collapse (Diamond, 2005)(Hunt, 2006).

However, further research is not so quick to label the Easter Island population collapse as just a result of careless human behaviour and overexploitation. Drought, winds, poor soil and no permanent streams meant Rapa Nui was never an ideal location for farming, even before colonisation in A.D.1200. Deforestation therefore had little effect on soils, since they were not particularly fertile in the first place. In fact, studies found the behaviour of the islanders may have in fact increased fertility. Paeloarcheology studies have identified the presence of Mania. These are circular rock lined enclosures that provide a productive stable environment for the propagation of staple crops. The walls protect plants from harsh winds and dehydration and household debris, ash and other organic material were added to increase soil nutrients. Although change did occur, the scenario in which reckless destruction lead to chaos seems extreme,  in fact communities manipulated their environment increasing productivity (Hunt, 2012). 

This however does not answer what actually caused the crash. The arrival of the Europeans by 1722 and subsequent visits is likely to have been the most destabilising factor. Although some propose it was the introduction of unfamiliar goods that rocked society, in fact the introduction of diseases such as syphilis and the taking of more than a thousand Raoanui as slaves probably had the greatest impact on population numbers in the islands history. (Hunt, 2009)(Rainbird, 2010). It is likely that evidence for a large population crash before settlers arrived was incorrect. Dates regarding the initial colonisation and subsequently the maximum population size estimated was misguided. 

Although now not the perfect example of uncontrollable exploitation of the environment by humans resulting in loss of biodiversity, degradation and then subsequent demise of that population, lessons should still be taken from Rapa Nui about our relationship with and dependence on the natural environment. Factors are so interconnected we must consider the short and long term impact of all behaviour to prevent future catastrophe. 

Sources:

Diamond, J. 2005. Collapse: How Societies Choose to fail

or Succeed. New York: Viking. 

Hunt T. 2009. ‘Rethinking the fall of easter island’. American scientist. vol 95(4). p412. 

Hunt, T. Lipo, C. 2012. ‘Ecological catastrophe and collape: The Myth of ‘Ecocide’ on Rapa Nui’ . Property and Environment Research centre. [online]. Available at: 

http://papers.ssrn.com/sol3/papers.cfm?abstract_id=2042672 . [Accessed: 12.12.2014]. 

Peiser, B .2005. ‘From Genocide to Ecocide: The Rape of Rapa Nui’. Energy & Environment 16. p3-4

Rainbird, P. 2010. ‘A message for our future? The Rapa Nui ecodisaster and Pacific island environments’. World Archaeology, Vol 33(3), pp436-451. 

Changes in human diseases or epidemiological transitions have always occurred during shifts in human social organisations and many scientists propose that we are about to enter another as a result of globalisation and ecological disruption (mcMichael 2001). Habitat complexity influences the composition, abundance and distribution of animals that play a role in the transmission cycles of many common human infectious diseases such as malaria and schistosomiasis. As a result, habitat and biodiversity loss influences transmission cycles by affecting the abundance, behaviour and condition of hosts or vectors (Keesing 2010).

Biodiversity affects the abundance of the host or vector organisms involved in disease transmission. For example, plants growing in experimental fields not hosts for fungal pathogens decreased the pathogen load of species that are hosts by reducing host density through competition (Mitchell 2002). 

Furthermore, the behaviour of host, vectors and parasites can change as a result of biodiversity loss affecting rates of transmission and prevalence in human populations. In more diverse habitats, a parasite is more likely to end up in an unsuitable intermediate host reducing the probability of infecting a human. This was demonstrated by studies on parasitic worms that cause schistosomiasis (Laracuente 1979).

Finally, biodiversity loss and human led habitat alteration clearly involves changing conditions. This can lead to increased encounter rates between pathogens and hosts when the host species has not undergone declines.  Furthermore, another plant study comparing genetically diverse and non diverse experimental fields found that those growing in species rich conditions had dryer leaves as a result of changes in microclimatic conditions and as a result had lower prevalence of a fungus. (Keesing 2010)

As ecosystem health and transmission processes are so nuanced, it is difficult to separate individual mechanisms to find direct cause and effect. Clearer patterns emerge when considering different infectious diseases independently. Malaria, one of the most damaging infectious diseases, resulting in 1 million deaths in 2007 alone is caused by one of four Plasmodium species via the female anopheles mosquito. Habitat alteration, particularly deforestation, is having a huge influence on transmission rates. Deforestation acts to raise surface water availability through the formation of puddles and pools that act as new breeding sites for the mosquito. Furthermore, microclimates as mentioned above are also affected. Larvas may be exposed to greater sunlight raising temperatures which cause mosquitos to digest more quickly so feed more often and lay more eggs. Higher temperatures affect the adult mosquito by reducing development time. In addition to this human factors clearly play a great role. Globalisation changes migration patterns and leads to the emigration of non immune individuals into high malaria risk areas affecting incidence and transmission (Pongsiri et al 2009).

As the links between ecosystems, biodiversity and disease occupy varying temporal and spatial realms and across political boundaries nuanced research is needed.  Furthermore, this is a relatively new field of study so there is far more to be discovered. Policy informed by this evidence can then be formulated that acts to preserve both human life and local and global habitats. 

Sources:

Keesing et al. 2010. Impacts of biodiversity on the emergence and transmission of infectious disease. Nature. Vol 468 (7324). pp 647- 652.  

Laracuente, A. 1979. Comparison of four species of snails as

potential decoys to intercept schistosome miracidia. Am. J. Trop. Med. Hyg. Vol 28. pp

99–105

McMichael, A. 2002. Population, environment, disease and survival: past patterns, uncertain futures. The Lancet. Vol 359. pp 1145-1148. 

Mitchell, C et al. 2002. Effects of grassland plant species diversity, abundance, and composition on foliar fungal disease. Ecology. Vol 83. pp1713–1726

Pongsiri et al. 2009. Biodiversity loss affects global biodiversity. Bioscience. Vol 59(11). pp 945-954. 

Drug Discovery 2

Much pharmacognosy is focused on cancer, as with over 10 million new cases in the year 2000 alone there is huge demand for new treatments. For example, the US’s National Cooperative Drug Discovery Group (NCDDG) is working on “Novel Strategies for Plant-derived Anticancer Agents” alongside several leading universities and pharmaceutical companies. 

They collected 5886 plant accessions from 2582 species with collections primarily carried out in tropical forests due to their capacity to support a very diverse range of taxa and species. 

Chloroform-soluble extracts were then prepared and screened by a variety of in vitro bioassays. Active extracts were then subject to ‘dereplication’ to determine of they contained previously isolated cytotoxic compounds. Treating cells with cytotoxic compounds can result in cells undergoing apoptosis (programmed cell death), necrosis (where cells lose membrane integrity and die via cell lysis) or stopping growing and dividing. Potential extracts are isolated by fractionation and further follow up studies are carried out on compounds of interest (Balunas, M et al.  2005).

Following from this initial collection and subsequent testing, 3 main chemicals are still undergoing further study. One chemical of interest includes Pervilleine A, found in extracts from the roots of the Madagascan plant Erythroxylum pervillei. This chemical acts to restore sensitivity of certain multi drug resistant cells, as the development of multi-drug resistant tumour cells is a serious problem associated with chemotherapy (Mi, Q et al. 2001).  

Further developments in cancer treatment drawing on plant resources have occurred in Australia. EBC-46 developed by the QIMR Berghofer Medical Research Institute is thought to destroy cancerous tumours by cutting of blood supply and is produced from the berry of  Fontainea picrosperma (Boyle, G et al. 2014).

It is clear then, considering global plant biodiversity and the extent of plant collection and subsequent testing required, preserving tropical forests and maintaining maximum biodiversity for future drug potential is a priority.   

Sources:

Balunas, M et al. 2005. Drug Discovery from Medicinal Plants. Life Sciences. 78(5). pp 431-441. 

Boyle, G et al. 2014. Intra-Lesional Injection of the Novel PKC Activator EBC-46 Rapidly Ablates Tumors in Mouse Models. Plos:One. [online]. Available at: http://www.plosone.org/article/authors/info%3Adoi%2F10.1371%2Fjournal.pone.0108887.[Accesssed: 19 November 2014] 

Mi, Q et al. 2001. Pervilleine A, a novel tropane alkaloid that reverses the multidrug-resistance phenotype. Cancer Research. 61(10). pp 4030- 4037. 

Conserving Drugs

The development of pharmaceutical drugs from plants is known as Pharmacognosy or ‘a molecular science that explores naturally occurring structure–activity relationships with a drug potential’. This encapsulates fields including plant ecology, ethnobotany, phytochemistry and molecular biology (Bruhn and Bohlin, 1997). The term has only been in use for the past 200 years although treatments from medicinal plants is clearly nothing new (Balunas, M. 2005).

The first records of plants as medicines were found in Mesopotamia dating back to 2500BC. These included oils of cedar and cypress as well as elements of liquorice and myrrh all still used today to treat a range of ailments from coughs and colds to inflammation. The world health organisation estimates that 80% of the global population still rely predominately on traditional medicine such as the above, although plant sources still play a surprising role in the drugs used by the remaining 20% (Newman et al, 2000). For example, in 2001 and 2002 a quarter of the best selling drugs worldwide were derived from natural products (Balunas, M. 2005). This includes Artemesinin  an anti-malarial drug derived from the Chinese herb Qinghao or Sweet Wormwood and Cromoglycate, a compound based on a chemical from the Khella plant used to treat asthma (Shetty, P. 2010). 

Artemesinin

Qinghao / Sweet Wormwood

The link between conservation and the search for new pharmaceuticals is clearly apparent. We never know when the next new drug may arise from so it is vital to preserve high biodiversity regions to preserve potential sources. Furthermore, it can be of great benefit to conservation efforts that may have previously focused on alternate issues if a new plant derived drug is found in an area.  In these cases governments are likely to place higher values on the area as a result of profit potential and future economic impact (Balik, 1994).

The protection of biodiversity for medical and health reasons is one of the most compelling arguments for conservation. However, it requires long term focus and planning considering the length of time between discovery and the large scale production of a drug. 

Sources:

Balik, M. 1994. Ethnobotany, drug development and biodiversity conservation -exploring the linkages. Ciba Foundation Symposium. 185. pp 4-18. 

Balunas, M et al. 2005. Drug Discovery from Medicinal Plants. Life Sciences. 78(5). pp 431-441. 

Bruhn, J. Bohlin, L. 1997. Molecular Pharmacognosy: An explanatory model. Drug Discovery Today. 2(6). pp 243-246.

Newman, D et al. 2000. The Influence of Natural Products Upon Drug Discovery. Natural Products Report. 17. pp 215-234.

Shetty, P. 2010. Integrating Modern and Traditional Medicine: Facts and Figures. SciDevNet. [online]. Available at: http://www.scidev.net/global/disease/feature/integrating-modern-and-traditional-medicine-facts-and-figures.html. [Accessed: 19 November 2014]. 

Floundering Fisheries

I always knew I would include a blog post on the impact of declining fish stocks but when it came about to researching for the post I was surprised. Compared to the sheer quantity of media hype over the plight of the bees there was very little concerning fish despite the wide ranging implications.

European fish stocks, and the UK's in particular, are in decline for a multiple of reasons including pollution and climate change yet it is direct human action through overfishing that is considered the greatest threat to marine ecosystems. Damage to marine ecosystems has far reaching impacts on human populations from protein consumption to employment to rural ways of life. 

Research on 43 european fish stocks assessed the impact of healthy, biodiverse fisheries on local employment and economies.  They found that 72% of stocks were below optimal level with €3 billion lost every year as a result. This money could support 100,000 jobs in the industry across Europe and boost local and national economies (Crilly, R et al, 2012) .  
Local economies, reliant on this primary sector have already experienced slow decline. For example, the Marine Conservation society and researchers from the University of York found that fishing fleet in the UK are having to work 17 times harder to make the same catch than the 1880s with peak fish landings in 1937. This is despite significant technological advances (Thurstan et al, 2010). With dwindling job opportunities and economic prospects, many face poverty or are abandoning this traditional way of life resulting in rural decline.

Marine ecosystems in Europe are a truly interdisiciplinary problem. A policy overhaul is required that balances the demands of human populations whilst allowing for recovery and then sustainable management. 

Sources:

Crilly, R et al. 2012. Jobs Lost at Sea. New Economics Forum. [pdf]. Available at: http://b.3cdn.net/nefoundation/e966d4ce355b7485c1_a7m6brn5t.pdf [Accessed 18.11.2014]

Thurstan, R. et al. 2010. The effects of 118 years of industrial fishing 
on UK bottom trawl fisheries. Nature Communication. [online]. 1(15). Available at: http://www.nature.com/ncomms/journal/v1/n2/pdf/ncomms1013.pdf. [Accessed 12.11.2014]

A Step In The Right Direction?

On Tuesday, Liz Trust the Secretary of State for Environment, Food and Rural Affairs delivered a speech on the link between the natural environment and the economy where she announced a number of interesting policy initiatives.

A highlight included the Wild Pollinator and Farm Wildlife Package, a 900 million payment scheme to encourage farmers to maintain hedgerows and strips of wildlife-friendly ground round the edges of fields, providing sources of food and nesting sites for insects. Other pollinator friendly initiatives included “Bees Needs” a website with guidelines and strategy to help individuals and groups improve their local environment for bees in both rural and urban areas and investment in research to gather more information on the condition of pollinators in the UK.

It is really encouraging to find an environment policy that has been so widely applauded as a step in the right direction, from conservation groups such as the RSPB to the Daily Mail. However, I do feel that initiatives such as this are a way of ‘greening’ the appearance of the current Conservative government whilst they continue to fail to tackle more complex issues such as our fossil fuel dependence (Trust, 2014). 

The full speech can be found here:  
Trust, E. 2014. Environment and the Rural Economy.   [transcript]. 4.11.2014. Available at:https://www.gov.uk/government/speeches/elizabeth-truss-speech-on-the-environment-and-the-rural-economy [Accessed: 6.11.2014]

Bye Bye Bees 2

In 2011, the United Nations Environment Programme (UNEP) published a report entitled Global Honeybee disorders and other threats to insect pollinators. This assessed the extent of honeybee decline and its causes.

Causes of honeybee decline have been linked to:

Habitat Deterioration:

- Degradation

- Increased pathogens

- Invasive Species

- Pollution

Agricultural practices:

- Chemical drifts

- Systemic Insecticides

Bee Keeping exercises:

- Health

- Chemical Use

- Types of flowering plant available

- Transport and colony splitting

Climate Change

Yearly Average of Managed Honey Bee Losses to Varroa Mite

The  Varroa mite is a particularly brutal pest for bee colonies. Varroa females enter last stage worker or drone bee larvae and feeds off the hemolymph of the prepupae, the pupae, and adults. Approximately 60hours after the bee cell is capped (the bee cells are the location of development in the hive), the mite begins to lay up to ten eggs. Once hatched, the Varroa mites suck the hemolymph from female adults and developing pupae of honey bees, weakening them and shortening life spans. The disease is thought to have spread so rapidly as a result of hive swarming and migratory bee keeping practices (Shen, 2005)(Sammataro, 2000). 

The mites significantly weaken individual bees but the impact on whole colony health is not as well known. However, several of the 18 viral diseases known to impact bee colonies were frequently encountered in hives infected by varroa mites. Studies by ball and allen 1988 used serological tests and found higher ABPV titers  in mite-infested colonies , suggesting that mites potentially activated the latent viruses (Ball and Allen, 1988). Others support the role of mites as honeybee disease vectors or as a stress factor.  To study these relationships effectively, completely virus free hives and mites are required, which is quite a challenge even in laboratory conditions (Shen, 2005). Furthermore, in wild colonies it is difficult to differentiate between the impacts of mites and disease with the alternate factors linked to honeybee decline as highlighted above. 

However, despite public fears across Europe and North America there has been an overall global increase of hives by 45% over the past 50 years. This is as a result of large scale human bee management techniques as opposed to wild colonies. To ensure sustainability, pollination and bee colonies require study and stewardship, not just managed colonies but also native pollinators (UNEP. 2010) 

Post updated 13.01.2015

Sources:

Ball, B. Allen, M. 1988. The prevalence of pathogens in honey bee (Apis mellifera) colonies infested with the parasitic mite Varroa jacobsoni. Annals of Applied Biology. Vol. 113 (1) . pp. 237–244

Sammataro, D. et al. 2000. Parasitic mites of honey bees: life history, implications, and impact. Annual Review of Entomology. Vol. 45 (1). pp 519-548. 

Shen, M. et al.  2005. The role of varroa mites in infections of Kashmir bee virus (KBV) and deformed wing virus (DWV) in honey bees. Virology. Vol. 342 (1). pp 141-149. 

UNEP. 2010. Global Bee Colony Disorder and Threats to Insect Pollinators. United Nations Environment Programme. [online]. Available at: http://www.unep.org/dewa/Portals/67/pdf/Global_Bee_Colony_Disorder_and_Threats_insect_pollinators.pdf. [Accessed: 31.10.2014]

Bye Bye Bees 1

Albert Einstein is supposed to have remarked that “Mankind will not survive the honeybees’ disappearance for more than five years.” Honeybees are a principle species of pollinators that work symbiotically with flowering plants transferring pollen resulting in fruit and seed production. The health and wellbeing of species such as the honeybee is therefore vital for sustaining habitats and human societies. 

70% of 124 main crops for human consumption are dependent on pollinators and studies by Gallai et al have attempted to assess the monetary value of pollinators using a bioeconomic approach. They used two main techniques;  assessing the total value of insect pollinated crops and a dependence ratio which calculates the production loss if there is complete loss of pollinators, the economic value of insect pollination service is equal to the corresponding loss of crop value. This is likely to vary among continents and regions due to the many crop species and heterogeneity in agricultural production.

They calculated the economic value of insect pollination for world agriculture at €135billion in 2005 which stands for about 10% of the world value of crops used directly for human food. This percentage is an indicator of the value of pollinator services relative to other factors contributing to agriculture production and therefore could be considered agriculture vulnerability.  They concluded that due to the nature of the agriculture industry (e.g. farmers adapting to pollinator loss by adopting new techniques) and the varied nature of pollinator decline it is difficult to assess the real significance of 10% vulnerability. When looking at this study alone, the fear of bee decline generated by the media seems to be a bit of an exaggeration (Gallai et al. 2008). 

However, global scale studies, particularly those looking to monetise ecosystem services, such as this will never be fully comprehensive.  This study failed to consider the value of pollinators  for seed production necessary for many vegetables grown for human consumption and seeds production for legumes often used to feed cattle. Furthermore, it failed to consider the pollination of plants that are not directly consumed; from wild plants vital to the overall health of ecosystems to biofuels.  In addition, the study principally focused on large scale agri-businesses, small scale farmers are already some of the most vulnerable people and often lack the ability to adapt. 

Sources: 

Gallai et al. 2008. Economic valuation of the vulnerability of world agriculture
confronted with pollinator decline. Ecological Economics. 68(1). pp 810-821.