June 25, 1998
Prelim questions from Shaw for Fitzsimmons
1. Many people believe that loss of biodiversity is among the greatest threats facing humans.
a. How do you feel about this topic?
I do not believe that even massive loss of biodiversity is a threat to human survival. However, it is a threat in that it greatly reduces the life total of the biosphere. As that pertains to us, it impacts the human experience. When we lose ecosystems, species or even a large portion of the genetic complement within species, the world is made less rich. It is a loss that can never be recovered. In most cases we can never know what was lost. The unrecognized beauty or the potential beneficial uses are gone before we can appreciate them. The role of that portion of the genetic material may or may not be known. I feel that we should strive to maintain all the diversity of life from a mix of personal, religious, aesthetic and practical reasons.
In the case of the large scale systems, the loss of diversity could have major environmental impacts. Floods from over-logging, drought brought on by removal of rainforest cover, insect plagues from removal of predators are examples of impacts from biodiversity loss. The only benefit of these cases is that the impact may be great enough to force us to react and reverse our damage. More dangerous is the slow loss of genetic material of individual species. In many cases we do not even realize how much of the diversity within a species has been lost until it is too late. The genetic complement can be reduced so low that there is not enough plasticity left to adjust to changing conditions and the species may become extinct.
The loss of biodiversity, even on a massive scale, is not likely to be a threat to the existence of humans. I expect that we can adjust and adapt to almost any biodiversity losses. We change and survive. Any potential losses that truly constitute a significant threat to our existence, would be met with a rapid infusion of resources. For example, a few years ago concerns were raised regarding the concentration of food production into just a small genetic base of grain crops. There were reports of loss of biodiversity in the corn, wheat, rice and millet used to feed much of the world population. This was based on the fact that much of the world production was in fact devoted to a few highly selected strains of seed. The fear was that a new insect pest or disease could wipe out production leading to mass starvation. In fact, there was already a world-wide effort to develop seed banks and conduct selective breeding programs that would retain and enhance genetic diversity. These programs were widespread and ranged in scale from individuals collecting and nurturing native seeds and plants to the biggest multi-national conglomerates and governmental bureaucracies. In addition, many crops that had fallen into relative disfavor have been resurrected. Some of these efforts were out of fear of loss of diversity and but many more were the result of economics. They cater to niche markets of consumers who want to try different foods and flavors, to people who have moved from one part of the world to another but want to still have some of their traditional foods, and to farmers who just want to grow something different as a challenge or for other environmental reasons.
In general I am more optimistic than some in our field. I will explain in greater detail in the section below on conservation strategies, but in short I have confidence that we will see a reduction in the rate of loss of biodiversity in the future. I think humans will always cause a disproportionate loss of genetic material amongst our fellow species, but my gut instinct is that we will learn to live much lighter on the land in the future.
b. Define biodiversity.
I consider biodiversity to be the sum of the ecosystems, species and their total genetic complement. Although the term biological diversity has been used for many years and native peoples have recognized the diversity of life for centuries, the term biodiversity was coined in the mid-1980’s. The contraction of biological diversity came from the planning stages of a conference on the subject and was used as the title of the proceedings (Wilson and Peter 1988) and was later popularized in the scientific (Ehrlich and Wilson 1991) and the popular (Wilson 1992) press.
In 1992 the United Nations sponsored a world conference on the subject in Rio de Janeiro. The Rio Convention declared Biological diversity means the variability among living organisms from all sources including, inter alia, terrestrial, marine, and other aquatic ecosystems and the ecological complexes of which they are a party; this includes diversity within species, between species and of ecosystems. (CBD, Article 2, 1992). This has become a defacto definition in the international environmental movement and in reprinted in many UN sponsored works on biodiversity.
The more difficult problem comes in trying to measure biodiversity. The first problem is encountered in developing a hierarchy of what should be measured. One example from Heywood and Watson (1995)
Organismal Diversity / Ecological Diversity / Genetic DiversityKingdoms / Biomes / Populations
Phyla / Bioregions / Individuals
Families / Landscapes / Chromosomes
Genera / Ecosystems / Genes
Species / Habitats / Nucleotides
Subspecies / Niches
Populations
Individuals
A simplistic measure is to select a geographic area and count the number of species in a particular taxon. This is a measure of species richness and is frequently used for comparative purposes. A slightly more sophisticated measure would count the number of species and number of individuals in each species. A still more sophisticated measure is to take the number of species, individuals and their degree of difference. This can be differences between taxonomic designations or ecological roles or some other criteria. Another measure is to select a particular geological era followed by the criteria described above using the fossil record.
c. List and explain the primary reasons why conserving biodiversity is considered by many to be so important.
Unknown ecological impacts - One of the primary reasons is the simple fact that we know so little of the interactions between species. We have seen how apparently minor changes in numbers of animals can have major impacts on entire ecosystems. Removal of predators allowing rodent populations to explode, loss of birds followed by insect invasions, and insecticides killing needed pollinators are all examples of how a small reduction in biodiversity can result in unintended consequences. These consequences can sometimes snowball and further reduce biodiversity so that a much more depauperate ecosystem is left. Monostands of single species of plants or bodies of water with only a single species of fish can sometimes be traced back to the removal of a particular plant or animal.
The interactions between vastly different taxa in natural systems provide a level of complexity that we can only partially understand and never really control. Often we do not realize the role that a constituent plays until it is lost from the system and its effects are obvious. For a while there was an interest in describing keystone species and top predators and how they impacted particular ecosystems. This was an instructive stage of ecological study but as it progressed it became obvious that even these models were too simplistic. There are just too many variables interacting to predict the effects of loss of one species. In a similar vein, the role of primary producers has been reviewed and predictions made regarding their loss. Again, real systems tend to be too complicated to predict results on a consistent level.
Loss of products or ecosystems of direct human use - There are many organisms that are used directly by human populations for food, fiber, shelter and other products. The loss of these species would have direct impacts on human populations. Forest, agro-ecosystems and many aquatic systems are heavily used by humans for production or collection of natural resources, loss of these systems could have even greater impacts.
Indirect impacts on humans - Certain ecosystems and species provide indirect impacts on human populations. Mangrove forests protect populations from flooding and storm damage, riparian areas and vegetated watersheds filter and retain water for human use, and forests and oceans absorb excessive CO2 and other pollutants generated by humans.
Loss of potential products of human interest - For many people a major concern over the loss of biodiversity is the anthropocentric view of what humans lose. Specifically the products that might have been developed. Many useful medicinal compounds, foods, fibers and fuels are probably lost when we reduce biodiversity.
Aesthetics - The sure beauty of living organisms is often enough to justify protecting organisms from loss. Historical records recount the amazement of seeing vast herds of buffalo and flocks of cranes that we have lost. With microphotography and electroscopy, even the smallest organisms demonstrate qualities and features that intrigue us. So that the loss of something we might have once thought inconsequential before is clearly worth protecting.
Religious - There are numerous religious aspects that direct us to protect forms of life. The Christian religions encourage believers to be stewards of the land and animals and to protect them from harm. Native Americans and other groups believe that all living things are linked spiritually and should be protected. Eastern religions also believe that humans are linked to other living things.
d. What are the primary strategies available to us to conserve biodiversity?
The strategies for conserving biodiversity can roughly be grouped into insitu and exsitu strategies (Heywood and Watson 1995). The insitu strategies include all efforts to protect the resources in their original setting. This would include preservation parks, reduction in harmful pollutants, protection from human development, ecotourism, endangered species protection, and habitat restoration. Exsitu strategies would include the use of seed banks, arboreta, museums, zoos, captive breeding programs, aquaria, tissue and cell cultures.
The protection of resources in place is the most important of all strategies. National Parks, Biosphere Regions and Wildlife Refuges are the best examples. Preservation of relatively whole and intact ecosystems is the single best method for maintaining biodiversity. Only large scale protection is likely to include sufficient habitat for the many species that together create functioning ecosystems. The rapidly developing approach of ecosystem management is also important. By approaching management of an ecosystem, often anchored by a park or other public lands, from an encompassing point of view, rather than a piece meal aspect, we increase the chance maintaining biodiversity. Obviously natural systems do not recognize boundaries created by humans. Ecosystem management has two major aspects; inclusion of appropriate stakeholders who have interests in the ecosystem and development of operating plans that incorporate all aspects of the ecosystem rather than individual species or habitats.
Reduction of harmful pollutants is another insitu strategy to protect biodiversity. Since the time of Rachel Carson and “Silent Spring” we have recognized that there are unanticipated impacts from human activities. The overall loss of diversity due to pollution is difficult to measure, but specific instances are quite numerous; DDT and birds, selenium and waterfowl, oil spills and marine mammals, PCB’s and striped bass, etc. By reducing pollutant input to natural preserves we further protect ecosystems and maintain diversity.
The loss of habitat and destruction of whole ecosystems due to conversion for human use is the greatest threat to biodiversity. Controls on destruction of habitat, especially on private lands, are needed in many regions if we are to maintain diversity. There are many innovative strategies to address this problem and we will probably need all of them to have much success. Sustainable development is a catch phrase that applies to many projects. For example, low impact farming with minimal tillage, irrigation, or use of chemicals is less harmful. Production of endemic crops or non-destructive collection of natural products has been shown to be successful. Payments from developed countries to less developed countries to set aside private property has been used as a mitigation for air pollution. Ecotourism has also been shown to be a valuable strategy to maintain biodiversity. Preservation of natural resources for tourism and for educational media programming can become a lucrative asset.
An additional strategy that has shown some success is protection of high profile endangered species. By physically protecting some species and their habitat, we have the direct benefit of maintaining that bit of biodiversity, but in addition there are usually side benefits. The relatively large organisms being protected often will harbor other species either in or on the endangered host species, or other species will be protected along with the critical habitat.
Habitat restoration is an insitu strategy that one would hope will become more common and successful in the future. Many degraded and depauperate areas can be restored and organisms can be reintroduced. However, these efforts are often expensive and difficult to achieve. The science is still developing and many efforts are still in the evaluation phase. Their are examples of habitat restoration; replanting of eel grass beds in Florida, removal of grazers from Kaho’olawe in Hawaii, replanting trees on farmland in New York; and reintroduction of organisms into former habitat; wolves, condors,and black-footed ferrets in Arizona alone.
The exsitu strategies are also important. Preservation of genetic material in seed banks, museums and botanical gardens provides a valuable insurance policy against catastrophes and extinction in the wild. Zoos, aquaria and captive breeding programs not only provide insurance and a reservoir of some biodiversity, they also provide a opportunity for some learning and scientific examination of behaviors and other characteristics that help us to understand their natural systems.
Tissue cultures, cell lines and genetic engineering are all tools that can be used as strategies to protect and conserve biodiversity. There are many examples of how these techniques can quickly increase numbers of individuals for reintroduction, but may not contribute as much to increasing the true diversity. Unfortunately these techniques also can be misused to flood a specific set of genes into an area to the detriment of the overall genetic complement. Genetic engineering and transgenics are techniques that provide more questions than answers when applied to maintaining biodiversity.
Some strategies are overlapping between insitu and exsitu. The most important of these is education. Educating the people within a particular ecosystem is critical to making them aware of what their impacts will be and how that will affect them and the natural resources around them. Many of these people have a deep respect and love for their surrounding but still destroy them from lack of understanding. For people living outside a particular system education regarding how their actions impact a distant region is also important. Knowing that their use of a particular product can help or hurt provides them with an opportunity to do something constructive (or non-destructive).
In summation, in my personal experience Iam encouraged that several of these strategies have been adopted around the world. The amount of environmental education that has occurred even in remote third world locations is impressive. Natural parks and biosphere reserves have been designated in most countries. The highest profile species and ecosystems have been the recipients of large amounts of scientific study and habitat protection. Ecotourism is growing and providing economic stimuli to the private sector to encourage conservation. However, the success of these strategies is still overwhelmed in many areas by the shear population growth and resultant demands on natural resources. The huge populations in developing country cities and the pall of air and water pollution emanating from these centers impacts huge areas. Iexpect that we are losing and will continue to lose large measures of biodiversity as whole ecosystems are lost as well as many species even within protected areas.
2. Legal instruments are essential tools for conservation.
a. In your opinion, what are the two most important laws, conventions or treaties which deal with global conservation issues. Describe the laws and why you feel they are important.
In my opinion, the CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora) and the Convention of Biological Diversity are the two most important legal instruments when we consider global conservation.
Convention on International Trade in Endangered Species of Wild Fauna and Flora (1973) - This was the first large scale international agreement to have virtually every country agree to protect biological resources. The convention operates by havinga committeewhich places species of concern on one of two appendices. Appendix 1 is the list of species which are considered to be endangered. Individuals and the products of organisms on the list are banned from international commerce. The intent is to remove themarket demand for live animal and plants or their products. By removing the demand, the economic pressure to harm the organisms is reduced. The convention seems to have been successful in several instances where poaching was a particular problem. It has also provided a forum for publicizing the plight of endangered plants and animals. Placing an organism on the list is the equivalent to being on the international endangered species list.