Conservation Biology (Biol 4350/5350) Fall 2012 Chapter 1: What is Conservation Biology?

1. Conservation Biology (Biol 4350/5350) Fall 2012 Chapter 1: What is Conservation Biology? (A fairly brief overview)

2. Almost all ecosystems on Earth have been impacted by humans to some extent; rate and degree is increasing exponentially with growth of the human population (about 6 billion people currently). Climate change, pollution, biogeochemical cycles, extinctions, habitat destruction and change, loss or alteration of genetic variation... Affects humans directly and indirectly.

3. 1.1 Estimated global human population size from the last Ice Age to the present

4. 1.2 United Nations projections for human population growth to 2050

5. 1.3 Number of global hectares per person needed to support current lifestyles

6. 1.4 Map of the human footprint

7. BUT: Human growth rate has slowed in many countries. Much depends on how people act and how much they consume, not just how many there are -- and consumption is much lower in 3rd World countries; this can change in developed countries too.

8. And: Highest birth rates are in places where many family members are needed to achieve success at low-skill tasks. Education and targeted economic development can reduce the incentive to produce large families.

9. Try to achieve a balance between human needs and maintenance of biodiversity through sustainable development. Conservation biology: Many ideas are old, but really became a science in the 1980s: ties together areas of biology such as wildlife and habitat management, to population genetics, to evolution, to ecological modeling etc. Integrates with chemistry, geology, anthropology, sociology, economics...

10. Elements unique to the “new” conservation biology: Spans the previous gap between pure and applied research; management plans consider genetic, theoretical, and many other kinds of data (not just counting trees, deer, etc.). Now, conservation biology is firmly established as rooted in real academic research.

11. 2) Earlier approaches were largely human-oriented (anthropocentric) and utilitarian: focused on maintaining species that people use or like (timber, fisheries, flashy species etc.), and “useful” components of ecosystems (e.g., water). Now much more concern about diversity of a wide range of species (which may in turn help preserve the ones that are directly useful to humans).

12. And -- growing recognition that biodiversity itself has inherent value; healthy ecosystems are the “support system” of the planet. (Also, wider view of “intrinsic value” -- biodiversity is valuable regardless of its direct benefits to humans -- we’ll discuss this more later).

13. 3) Realization of the importance of integrating conservation strategies with work of non-scientists: economics, politics, social sciences, urban planning, etc. People have to cooperate, establish viable alternatives, and understand the benefits of preserving biodiversity.

14. In the broadest sense, conservation biology tries not only to maintain diverse species, but also genetic diversity and genetic “integrity”: protect populations and gene flow. And, keep entire ecosystems functioning normally while recognizing that change (ecological, evolutionary) does occur even without human intervention.

15. Conservation biology, from a scientific perspective, is an attempt to maintain normal evolutionary processes within normally functioning ecological settings.

16. Even in ancient Greece (for example), massive habitat destruction was in progress, and was recognized. Huge areas of S. Europe, Mediterranean, and SW Asia were once called “the land of perpetual shade”; forests were destroyed to build ships etc.; now barren and/or desert.

17. The degree of human impact has depended partly on population density and partly how long people stayed in one place. Small groups of hunter-gatherers often have low impact; move on when local resources become scarce and resources can regenerate.

18. Some societies practiced sustainable agriculture, using selected areas, moving on, and allowing these areas to go through normal successional stages. But as agriculture became more sophisticated and permanent, ability of ecosystems to regenerate diminished. And -- demand for resources continues to grow.

19. Europe was essentially deforested by the 1700s, except for land held by the rich; many areas of China etc. similar. So, by the time there was a real interest in conservation, much of the natural habitat was lost. North America: Originally aboriginal peoples; probably low impact (except hunting of large mammals?).

20. Then: European colonization, exploitation of forests and other resources. And -- a lot of resources were sent back to Europe, where the demand was much greater; exploitation was no longer just local (and this continues to be a problem throughout the World).

21. Early approaches to conservation biology in the U.S.: • Romantic-Transcendental Conservation Ethic: Rooted partly in the writings of Thoreau, Emerson, Muir. Philosophical view that nature is the work of God -- a “temple” -- not just for human/economic benefit. Today, this view is exemplified by groups such as the Sierra Club.

22. 2) Resource Conservation Ethic: Formalized around the beginning of the 20th Century by Pinchot, following J.S. Mill and others. View of “useful” versus “non-useful” components of nature (an anthropocentric approach). Multi-use concept: get as much as possible out of an area (timber, fish, grazing, etc.); develop management strategies to achieve this.

23. Still seen with groups like the Forestry Service, fisheries management agencies, Ducks Unlimited etc. This established the “preservationist” versus “utilitarian” schools of thought. Then 3) Leopold’s Evolutionary-Ecological Land Ethic (EELE): mid-20th Century.

24. Still seen with groups like the Forestry Service, fisheries management agencies, Ducks Unlimited etc. This established the “preservationist” versus “utilitarian” schools of thought. Then 3) Leopold’s Evolutionary-Ecological Land Ethic (EELE): mid-20th Century.

25. EELE was rooted in the emerging science of evolutionary ecology. Can’t just break nature into “useful” and “non-useful” elements, and need to understand how it works. Study various components of ecosystems and their interactions to protect them as a whole in an informed way. Larger an “equilibrium” view (shifted more to non-equilibrium as knowledge grew).

26. The EELE provided the broadest and most useful approach, and much of the fundamental basis of modern conservation biology (although now, there’s much more emphasis on the human element as well).

27. 1960s-1970s: Biologists started to wake up to the fact that entire ecosystems were disappearing; biodiversity was disappearing rapidly; also, pollution and other human-induced problems gained wide awareness. Conservation efforts at the time were largely utilitarian or focused on appealing species; need for an ecosystem approach became evident.

28. 1980: Soulé and Wilcox published Conservation Biology: An Evolutionary Perspective Major turning point, followed by other works that emphasized evolutionary biology as much of the basis for conservation.

29. 1985: Society for Conservation Biology (and their journal Conservation Biology) were established. Provided a venue for evolutionary and genetic approaches to conservation. The field continues to grow, integrating a wide range of areas of science (including new genomic tools) and study of human activities.

30. Our text: Three guiding principles that establish a paradigm (“world view”) for conservation biology. 1) Evolutionary change: A unifying theme throughout biology: explains origins and patterns of biodiversity; genetic change is central to evolution; don’t want to stop evolution -- instead, ensure that populations and species experience natural genetic change, including adaptation, in response to natural forces.

31. 2) Dynamic ecology: Ecological systems are rarely at equilibrium, and if so don’t stay that way long -- no truly stable point. External forces -- floods, fires, invaders, etc. can “perturb” the system or change it drastically; ecosystems are usually patchy and shift over time.

32. This view is directly relevant to factors such as preserve design; e.g., habitat corridors to allow movement and gene flow, and consideration of temporal factors. And of course -- ecosystems are inherently dynamic because evolution of the organisms within them is happening all the time.

33. 3) Human presence: Can’t leave humans out of the picture; we’re here to stay (?), and people won’t support conservation efforts if natural areas are simply barricaded off etc. Need to consider human needs, educate/build pride in local habitats, tie conservation to economic incentives, recognize rights of native groups -- and also, incorporate the knowledge that they have of the ecosystems and organisms.

34. Conservation biology is inherently interdisciplinary, and also inherently inexact in many ways: blending complex systems, human components, “hard” versus “soft” science, public policy etc. And, since ecology and evolution are not strictly predictable, there’s a strong component of probability, plus the need to consider many factors that could alter expected outcomes -- need to build in safety margins.

35. 1.9 The interdisciplinary nature of conservation biology

37. Chapter 2: Global biodiversity: Patterns and processes

38. Biodiversity (biological diversity -- here diversity is used in a broader sense than we’ll use later): Variation across Life. What kind of variation?

39. Essay 2.1 (A) Compositional, structural, and functional attributes of biodiversity

43. Genetic diversity: Determines every level of biodiversity. Number of genes ranges from a few (viruses), to several hundred (many bacteria) to tens of thousands (e.g., humans: 20,000 +). Genetic variation is constantly arising (mutation, recombination): essential to evolution.

44. Levels of genetic variation are often considered indicators of the “health” of a population or species: may provide resilience to changing conditions. Also critical in captive breeding and management.

45. Understanding genetic diversity is essential to understanding gene flow, population structure, intra- and interspecific interactions, relationships to environment, species boundaries and evolutionary history...

46. Population level diversity: Describes, in part, nature and distribution of genetic variation within and among populations. e.g., local adaptations; species-wide variation (disease resistance, nutrient use, etc. And: genetically-determined phenotypic plasticity may be very important.

47. Prioritization of populations for conservation: maximize diversity? Different populations may play different roles in different ecosystems (may or may not be genetically determined). e.g., a pollinator, predator, etc. may be crucial in some systems: not always obvious until after it’s gone.

48. 3) Human cultural diversity: Cultures evolve too, and interactions with environment vary tremendously (good and bad): many have a long history of managing/sustaining natural resources. How many human cultures are there? Over 6500 known languages (one indicator).

49. Can also measure by number of indigenous populations: generally highest in tropics (where biodiversity is usually highest too). So: complex human/environment interactions; these determine cultural adaptation. Often overlooked, especially in context of conservation strategies.

50. 2.1 Linguistic diversity and numbers of indigenous cultures across the world (Part 1)