Conclusion: Human Well-being and Biodiversity
The emphasis of the Ecosystem Status and Trends report for the Mixedwood Plains (Key Findings 1 to 22) has been on human impacts on the ecozone+’s biodiversity (structure, composition, and function) however, the biodiversity of the ecozone+ plays a critical role in determining the well-being of the humans that live within it. Maintenance of natural levels of biodiversity is necessary for proper ecosystem functioning and the provision of ecosystem services to humanity.472
Ecosystem services are the aspects of ecosystems utilized directly or indirectly to produce human well-being (see Ecosystem services for further detail).281,473,474,475 These life supporting services are typically undervalued by society and our market economy.281,475 Their value often goes unrecognized as our understanding of ecosystem services is still developing.476 They are worth billions of dollars per year, but need to be valued more accurately because their loss has massive economic impacts threatening health, food production, climate stability, and basic needs such as clean air and water.281,319,451,477,478
The most comprehensive review of the state of the planet and the resultant state of human well-being ever conducted is the Millennium Ecosystem Assessment. Established in 2001 as collaborative international program, it determined that human activities have changed most ecosystems and threaten the Earth’s ability to support future generations.281 The scale of change to our planet is great enough that the Stratigraphy Commission of the Geological Society of London has a working group trying to decide whether a new geologic time period, the Anthropocene will become a recognized time period of the Earth’s geologic history in recognition of the extent of change that has taken place due to human activity.480 It has been suggested314 that there are specific planetary boundaries within which humanity needs to operate in order to insure we avoid major human –induced environmental change at a global scale. Seven of these global boundaries have been established: CO2 levels below 350 ppm, a less than 5% decrease from an ozone level of 290 Dobson units, nitrogen fixation of no more than 35 Tg N/yr, phosphorous inflow to the oceans of not more than ten times the amount from natural background weathering, consumption of freshwater of less than 4000 km2 /yr, less than 15% of ice-free land as cropland, and a rate of species loss of less than 10 extinctions per million species/yr.314 If we remain within these boundaries it is suggested that we are free to pursue long-term social and economic development without concern for environmental collapse. Globally we have already surpassed three of these boundaries (CO2, nitrogen and species extinctions). It is not known where the Mixedwood Plains stands relative to most of these measures but it clearly exceeds the 15% of land in cropland as there is 68% cover of agricultural land in the ecozone+. The Mixedwood Plains is one of the smallest of Canada’s ecozones+, has 53% of the country’s human population444 yet still has one of the highest levels of plant species diversity in the country.13 With the human population expected to continue to increase, dominantly agricultural land cover (Agricultural landscapes as habitat ), continued agricultural intensification and urban expansion (Ecosystem), high levels of invasive species and pollution (Invasive non-native species , Contaminants , Nutrient loading and algal blooms , and Acid deposition), there is concern for the overall health of the ecosystems within the ecozone+ as well as concern about the implications for its human inhabitants.
The Ontario Biodiversity Council in partnership with the Ontario Ministry of Natural Resources has examined the state of Ontario’s biodiversity through Ontario’s Biodiversity 2010 Highlights Report. This report assesses the health of Ontario’s biodiversity using 29 different indicators.213 Of the 20 indicators that examine either pressures on biodiversity or the state of Ontario’s biodiversity (direct measures of the ecosystem), the dominate trend was one of deterioration (8 of 20 indicators).213 Many indicators showed that the threats to Ontario’s biodiversity were most intense in the Mixedwood Plains ecozone.213 Of the nine measures of conservation and sustainable use, most showed improvement (five of nine).213 Though Ontario’s ecosystems are not yet experiencing any improvements in condition, there has been improvement in conservation and stewardship. The key findings for the Mixedwood Plains are consistent with the Ontario Biodiversity 2010 report as they show pressures on biodiversity through the issues of habitat loss and fragmentation (Theme: Biomes section, Ecosystem , and Intact landscapes and waterscapes ), species loss (Agricultural landscapes as habitat , Species of special economic, cultural, or ecological interest , and Food webs ) invasive species (Invasive non-native species ), climate change (Ice across biomes and Climate change ), and pollution (Contaminants , Nutrient loading and algal blooms , and Acid deposition ) while showing improvements in stewardship (Stewardship ).
Though all ecosystem services contribute to human health and well-being, there are three ecosystem services that have very direct links to human health: constraint of infectious diseases; provision of medicinal resources; and improved of quality of life.481
Constraint of infectious disease
Globally, evidence that high biodiversity can protect human health by reducing the risk of certain infectious diseases is growing.482,483 When the global incidence of rodent-borne hemorrhagic fevers was examined,484 it was found that all the outbreaks occurred in highly disturbed habitats which had low biodiversity and that in each case the rodent host was a generalist/opportunistic species which did well in human disturbed areas. In Panama, experimentally induced decreases in small mammal diversity caused increases in hantavirus prevalence (hantavirus can infect humans) in the viral host small mammal population as well as an increase in the size of the host population.485 When the impacts of habitat fragmentation and species loss were examined in a field trial in Panama,486 it was found that habitat loss, fragmentation and species loss were altering hantavirus infection dynamics and that greater species diversity likely reduces the number of encounters between infected and susceptible hosts thus reducing the spread of the virus.486 Similar results were found an outbreak of hantavirus in central Bolivia.487
Both West Nile Virus (WNV – transmitted by mosquitoes) and Lyme disease (LD – transmitted by ticks) are found in the Mixedwood Plains and research into their dynamics reveal similar findings as to what is being discovered about biodiversity and the transmission of disease globally. When there is a high diversity of species for the disease bearing mosquitoes and ticks to feed upon, and most of the species are poor reservoirs for the diseases of concern, then there is a very low infection rate of these diseases within the human population, however, when there are few species for the mosquitoes and ticks to feed upon, and those available are good reservoirs for the pathogens, there is a high rate of infection within the human population.488
In the case of WNV, some of the best reservoirs for the virus are common bird species such as American robin, American crow, house sparrow, blue jay, common grackle, and house finch, all of which are highly adapted to living in human modified environments. When the incidence of WNV and bird diversity were examined at the county level in the United States, it was found that as bird diversity went down, the incidence of WNV went up.488
The primary reservoirs of Lyme disease are white-footed mice, eastern chipmunks, short-tailed shrews, and masked shrews and all but the masked shrews are abundant in degraded and fragmented habitats. One of the major factors determining the species richness of terrestrial mammals in many areas is the actual size of the habitat area. When the prevalence of Lyme disease in ticks was examined relative to the size of forest habitat areas in Dutchess County New York State, it was found that as patch size decreased the rate of infection with Lyme disease increased,488 again indicating that decreased biodiversity is associated with increased disease.
A study of the prevalence of antimicrobial drug resistance in E. coli bacteria found in small mammals done in the Ottawa area,489 found that wild mammals living in the proximity of farms were generally more likely to harbour antimicrobial resistant bacteria (such as bacteria resistant to tetracycline) than wild mammals living in natural areas. These results suggest that the use of antimicrobial agents in farming, may have a impact on the amount of antimicrobial resistance seen in nature.489
Provision of medicinal resources
Plants have been used as a source of medicine throughout history and continue to serve as the basis for many pharmaceuticals used today.490 An example of a drug derived from a native species found within the Mixedwood Plains Ecozone+ is the cancer fighting drug “Taxol”. Taxol can be derived from both the Canada Yew (Taxus canadensis) and the Pacific yew (Taxus brevifolia). Canada Yew is a common understory shrub found in the mature forests of the ecozone+. Once considered of little commercial interest, it is now prized by the pharmaceutical industry.491
Plants are not the only sources of medicinal resources, mammal venom is also being investigated for potential medicinal use.492 Though the scientific research has not been completed, patents have been issued for the use of soridicin493,494 (the venom of the northern short-tailed shrew, Blarina brevicauda, which is found throughout the Mixedwood Plains) as an analgesic, a wrinkle treatment, a mechanism to immobilise muscles to treat neuromuscular diseases, and a treatment for excessive sweating.492
In a study of plants traditionally used by the Cree Nation of Quebec in the treatment of diabetes,495 three species (pitcher plant Sarracenia purpurea, Labradour tea Rhododendron groenlandicum, and black spruce Picea mariana ) were found to be especially promising candidates for in-depth analysis. All three of these species are found in many of Canada’s ecozones+, including the Mixedwood Plains.
These are only a few examples of medicines derived from species which are part of the biodiversity of the Mixedwood Plains. Clearly, biodiversity loss decreases the supply of raw materials for drug discovery.483,496
Improved quality of life
The quality of our lives is also impacted by biodiversity. Many studies have shown positive psychological benefits associated with green space.497,498,499,500 Simply being able to see nature through a window has been associated with faster recovery rates in hospital,501 lower levels of illness with inmates, lower heart rate,502 higher job satisfaction,503 and better student test scores.504 Actually being in contact with nature has been shown to have a positive impact on blood pressure, cholesterol, outlook on life, and stress-reduction.505
A study done in the Netherlands498 found that people with a greener environment within a 1 to 3 km radius around their homes had better self perceived health than people living in a less green environment. The perceived general health of people living in less urban areas tended to be better. Analysis of the effects of green space in different age groups (youth 0 to 24, adults 25 to 65, and elderly 65 and older) showed that the health of all age groups benefited significantly from green space. When educational level was examined, people with lower education levels were more sensitive to the physical environmental characteristics.498 The degree of possible psychological benefit that a green space has seems to be related to the diversity of the area. In a study done in Sheffield England,497 it was found that the degree of psychological benefit was positively related to species richness of plants and to a lesser extent of birds. People’s sense of identity and ability to reflect increased as plant diversity increased while their emotional attachment to their neighbourhood increased as bird diversity increased.497 People also appear to like green spaces much better than areas without vegetation. A study done in Chicago Illinois500 found that, on average, 90% more people used green spaces than barren spaces and on average 83% more individuals engaged in social activity in green versus barren spaces. For females, greener spaces were found to support proportionately more social activity than barren spaces and the location of the spaces (front, back, or side of the apartment building) was not related to the amount of social activity that took place.500
Given the wealth of evidence that human well-being is dependent on biodiversity, the question remains as to why humanity is allowing the biodiversity that sustains it to be negatively impacted. Research indicates that the extraction of raw materials from the environment and the dumping of wastes into the environment are grounded in the quest for minimizing costs of production to maximize profits.506 The assumption has been that stressing of the environment improves human well-being.506 There is increasing evidence that this is not true. In an analysis that examined 135 nations,506 it was found that if you controlled for physical and human capital, exploitation of the environment has no net positive effect on well-being (life expectancy at birth was used as the measure of well-being). When affluence was examined relative to happiness,507 it was found that growth in affluence for very low income countries can substantially improve well-being, but this benefit rapidly diminishes so that for affluent countries, further economic growth does little to improve human well-being (a relationship of diminishing returns506). A study done in Illinois where people were asked whether they considered themselves a part of nature, and what nature was,508 yielded some very interesting and dissonant findings. Most participants (76.9%) considered themselves to be a part of nature, but interestingly 32.3% of these participants, as well as 63.6% of those who described themselves as separate from nature, perceived nature as an entity that does not involve humans. These two perceptions are at odds with each other. Most research has suggested that the more exposure people have to nature, the more connection they feel to it508 and the study respondents who considered themselves part of nature talked about their experience with nature but defined nature specifically by the absence of humans. Dissonance is generally considered to be unpleasant and people relieve themselves of the contradictory perceptions by rationalizing or denying subsequent thoughts and behaviour.508 How this sort of dissonance is relieved could have resource management implications. If, in order to relieve the contradictory perception a path of greater levels of environmental responsibility is pursued, the outcome will be very different than, if the environmentally destructive behaviour is rationalized in order to relieve the dissonance.508
Significant challenges remain for the Mixedwood Plains Ecozone+ as its population increases, resources continue to be used, climate change impacts increase, and the ecosystem continues to be degraded. Moving from where we are, to where we need to be will require not only expanding our scientific understanding of the ecozone+, but finding mechanisms through which good stewardship is not seen as luxury but as essential for human well-being.
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