Presentation is loading. Please wait.

Presentation is loading. Please wait.

Explanatory Theories of Degradation NREM 612. 2 I. EXPLANATORY THEORIES OF DEGRADATION Degradation as much an: economic, social/cultural, & political.

Similar presentations

Presentation on theme: "Explanatory Theories of Degradation NREM 612. 2 I. EXPLANATORY THEORIES OF DEGRADATION Degradation as much an: economic, social/cultural, & political."— Presentation transcript:

1 Explanatory Theories of Degradation NREM 612

2 2 I. EXPLANATORY THEORIES OF DEGRADATION Degradation as much an: economic, social/cultural, & political problem as it is a biophysical problem (Eswaran et al. 2001)

3 3 A. Natural Factors/Disasters (independent of human activity) 1. Some areas more prone to degr.: What are some examples? How many of these apply to the Hawaiian Islands?* Steep slopes Areas subject to intense rainfall Drylands or drought-risk areas Hurricane-prone areas Lowlands close to sea Areas w/ earthquake, volcanic activity Areas w/ easily-damaged soils Areas subject to invasion by exotic spp. * * * * * * *

4 4 2. WORST CASE = human-induced degr. in disaster-prone areas i. examples: clearcutting forests leads to landslides in SE Asia, or wetland loss in coastal Louisiana + Katrina + Deep Horizon/BP oil spill

5 5 B. Population Pressure 1. Malthusian view. Who was Malthus? a. predicted earth would outrun food supply by mid- 19th cent. b. based on idea that population, if unchecked, increases @ geometric rate whereas food supply grows @ arithmetic rate a. Rev. & Prof. @ Haileybry College, lived 1766-1834 2. In 1798 wrote: Essay on the Principle of Population

6 6 P(t) = P o e rt Time Population Resources Point of Crisis Limiting factors in nature, i.e. food production, stay constant or grow linearly Time Population Carrying Capacity (CC) When CC is reached, limiting factors begin to take place P(t) = mt + b P o = initial population r = growth rate t = time

7 7 4. Was Malthus’ correct? Some argue main reasons he was wrong were Transportation & Medical Revolutions, Haber-Bosch, Green Revolution Others argue just a matter of time... c. ↑ pop pressure causes overuse of quality land, misuse of marginal land d. Double edged sword: ↑ demand on env, & ↑ degr. 3. Caveats? a.areas w/ high pop. density, & low degr. (e.g., Japan) b.areas w/ low pop. den., & high degr. (e.g., Iceland, Australia)

8 8 In the time since Malthus introduced the idea: Population increase is frequently cited as the cause of land degradation As increasing demographic pressure builds and high quality land is overused, marginal land, that often is more easily degraded, is used (Barrow 1991). In the current food vs fuel debate over bioenergy production: Proposed that non-prime agricultural land (i.e., marginal or degraded lands) be used for fuel production. What implications are there for this?

9 9 C. Poverty (Marginalization) 1. Puts focus on immediate needs, not long-term sustainability a. Pov. induces degr., which induces pov., induces degr. i. INTERACTION of damage to veg. & soil (Brady & Weil 1999) Positive Feedbacks

10 10 2. Exceptions: Not all poor farmers cause degr, nor do all rich farmers prevent it. “All countries, rich or poor, arid or humid, cool or tropical suffer it (from Barrow 1991)” a. Ethiopia: poor farmers invest more in land than rich, because they’re wholly dependent on land b. Trop. forests: Commercial agents more important actors pursuing logging than poor farmers (Repetto 1990, Goodland 1991, Duraiappah 1998)

11 11 D. Land Ownership/Tenure 1. Public land: degr. occurs, controlled by regulations, pricing, public works 2. Private land: degr. diff. to control, occurs when owners seek short-term profits a. Don’t wait for unforeseen benefits of conservation 3. Security of ownership implicit in willingness to invest $, labor in cons. (Stocking 2001) a. w/ secure tenure, poor farmers exhibit sustain. activities (Duraiappah 1998)

12 12 4. Common property: degr. occurs as individuals seek to maximize gains a. Tragedy of Commons ~ demand of individual small, when pursued by many, degr. occurs (Hardin 1968) b. Herder example:

13 13 E. Economic Factors 1. Entrepreneurs maximize short-term profits a. cause degr., invest profits elsewhere, avoid consequences b. CEOs, BoDs don’t care about deforestation in dvping countries 2. Incentives/disincentives a. Ag. price structures favor urban purchaser over rural vendor (no incentive for conservation) 3. Subsidies often distort farmers’ priorities a. i.e. grow tobacco when unsustainable b. will not conserve w/o incentives Exceptions: Consumer/market preferences -Boycotts (e.g., Styrofoam) -Demand for organics and or free range animal products

14 14 4. Free market economy: No inherent financial value to natural ecosystems, so a free-market society will not protect the environment a. Ecosystem services neither produce goods nor have defined ownership, economic valuation remains difficult (Foley et al. 2005)

15 15 F. Social/Cultural Factors 1. Weddings & funerals & festivals a. farmers/ranchers overuse land to generate $ for W & F 2. Certain pastoral societies a. herd size assoc. w/ wealth & social standing b. herders keep as many animals as possible despite assoc. degr. Exceptions: Positive social pressures, e.g., curbside recycling

16 16 G. External Factors 1. World markets fluctuate beyond local, regional control (Vandermeer 2011, from Vandermeer & Perfecto 2005) 2. Legacy of Colonialism a. Trade links, communications, & linkages promote exploitation b. Neo-Marxism? - dvped countries achieve(d) wealth by exploiting dvping

17 17 H. Political Instability & Poor Admin. 1. Political instability puts focus on immediate survival, not conservation a. 70% of Africa experienced conflict since 1950s (Harrison 1987) i. Africa:10% of world pop, 50% of refugees (Barrow 1991) b. Afghanistan @ war since 1970s c. Haiti (Diamond 2004)

18 18 a. Gov’t refuses to acknowledge degr. b. Gov’t decrees bad policy, adheres to it stubbornly c. Special interest groups discourage reaction to degr. i. pride, ignorance, etc. ii. instead of admitting it was wrong 2. Poor Administration

19 19 I. Inappropriate Technology 1. Western attitudes, science a. In various cases, replaced estab., successful non- western practices, w/ negative results 2. Culturally insensitive solutions a. Ex: fenced paddocks to control overgrazing in Africa b. doesn’t fit w/ idea of common property access, use

20 20 Ask mankind their views about the land: -Land in use -Land to be used -Land that is useless Perception of the utility, i.e., the productive capacity of land dominates the human psyche 1.Until land degradation impacts the economy, tends to go unnoticed -Massive events, landslides, Dust Bowls get attention -Gradual losses are much more threatening 2. Poverty and powerlessness contribute enormously to degradation -May know what it happening -Unwilling or unable to do anything about it because survival is primary 3. What is one man’s loss may be another’s gain -Difficult to agree on whether degradation is occurring -Does degradation need attention? When action is taken, it is often the easy solution that is chosen. (Barrow 1991) SUMMARY

21 21 II. MODELS FOR PREDICTING/UNDERSTANDING DEGRADATION To determine the significance of land degradation you must be able to assess it. -Measurement has always been difficult -In the 70’s economists dismissed environmental matters as intangible and therefore immeasurable and not to be included in analysis (Barrow 1991)

22 22 A. Exploitation of land has been described as a “Lollipop Model” (Chisholm & Dumsday 1987) -With each act or lick, less is available for future -But, with good management it might be possible to sustain land for indefinite usage How fast are we licking? How long will the lollipop last? Is the process reversible?

23 23 B. Net Degradation Model (Barrow 1991 uses this to define degradation) Net Degr. = Nat. Degr. Processes + Human Interference Natural Reproduction + Restorative Mgmt. + (-) (+) Net Degr. Forest = Example Geol. Erosion + Clear Cut Reforestation of landslide + Invasive removal & native planting + Definition (from Barrow 1991): “Land degradation is something that can result from any causative factor or combination of factors, which reduces the physical, chemical, or biological status of the land and which may restrict the land’s utility, or productive capacity.”

24 24 C. I = PAT Model Describes the impact of human activity on the environment (Ehrlich & Holdren 1971) Impact = Population * Affluence * Technology Pros & Cons of model? Elegantly simple or oversimplification? Linear relationships? Interactions? Affluence? Consumption: industrialized countries, per capita consumption of resources is 5x that of non-industrialized

Download ppt "Explanatory Theories of Degradation NREM 612. 2 I. EXPLANATORY THEORIES OF DEGRADATION Degradation as much an: economic, social/cultural, & political."

Similar presentations

Ads by Google