ENVS 202 1st Edition Lecture 3Outline of Last Lecture I. Shifting BaselinesII. Tragedy of the CommonsIII. Feedback LoopsOutline of Current Lecture I. Review of Feedback LoopsII. Willamette Valley, Then and NowCurrent LectureI. Review of Feedback LoopsPositive feedback loops are self-reinforcing loops. . . an increase in one variable leads to further increase in that variable, or decrease leads to further decrease. . this has nothing to do with whether it is beneficialNegative feedback loops are self regulating. . . a system will balance itself out, such us more zooplankton means more fish, more fish means less zooplanktonII. Willamette Valley, Then and NowForests: from: savanna-like in hills, extensive along the river . . . to: dense in hills, replaced with other land uses along river . . . Impact: oak/scrub reproduction boomsAgriculture: from: none, land was used as needed, techniques for ‘farming’ primary foodsources were natural (fire) . . . to: what most of the area is used for, major land use . . . impact: Land goes from natural prairies and savannas to agriculture and industry, there is habitat loss, air pollution, and fossil fuel consumptionWillamette River: from: wider, less controlled, complex . . . to: channelized river which lacks complexity . . . impact: some river habitats were eliminated, greater potential for impact on human structuresThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Wetlands: from: extensive, dominating . . . to: replaced with agriculture or urban lands . .. impact: more land is available, loss of this habitat, loss of the filtration and absorption capabilitiesNative Prairie: from: all of the land, carefully maintained by Natives, dominated by tall grasses and fertile soil . . . to: land now dedicated to agriculture, minimal prairie . . . impact: oak and scrub reproduction booms without the fires, land is farmed by industryRiparian Vegetation: from: dense, extensive . . . to: patchy, conifers mostly removed . . . impact: loss of habitat for riparian species, increased water temperature, impaired waterqualityFish/wildlife habitat: from: extensive availability . . . to: decrease in natural habitat . . . impact: loss of natural biodiversity, some extinctionWater Quality: from: natural state, all natural growth of riparian area, high oxygen . . . to:much smaller, less vegetation, likely pollution increase with surrounding pesticide/herbicide-using farms . . . impact: decline of susceptible aquatic species, difficult/expensive to produce clean