220 likes | 321 Views
Lecture 8: Anthropomorphic Change. Farming, Oysters, & Succession. Objectives. Understand how the colonists altered the land surrounding the Chesapeake Bay Understand how the colonists altered the near-shore communities of the Chesapeake Bay. Farming.
E N D
Lecture 8: Anthropomorphic Change Farming, Oysters, & Succession
Objectives • Understand how the colonists altered the land surrounding the Chesapeake Bay • Understand how the colonists altered the near-shore communities of the Chesapeake Bay
Farming • Indians method of farming maintained the topography of the land • No metal implements e.g. axes or plows • treated land as gift from Manitou • Colonists method of farming altered the topography of the land • Metal implements used to fall trees and till soil • Land belonged to colonial user
Tobacco • Chief cash crop of colonists (big buck export item used to make cigars) • First cultivated in Chesapeake Bay Region by John Rolfe (came from West Indies) • Demands rich soil • Depletes soil of nutrients in ~ 5 yrs. so there was a great need to clear more land • Labor intensive crop demanding additional workers
Tobacco Pictures • Tobacco requires • early germination under burlap • planting • topping • harvesting • drying • rotation
Oysters • Sessile (cannot move so cannot run away) • Tasty? • Can be eaten year round although best during months of the year containing “R” • Readily available during colonial time
The Oyster Story • Oysters record changes in Bay conditions • “Meats” accumulate heavy metals & environmental toxins as a result of the oysters feeding via the “filter” method. • “Shell” is a permanent record of Bay conditions and position in the water column. The shell (mantle) grows daily trapping water within the shell. Growth is modified by temperature and pressure
Oyster Story • 3 shell morphologies • Sand oyster: • ridges on shell • height roughly = width • Mid-water oysters • no pronounced ridges • length exceeds width • Tongue Oysters • length >> width
Colonial Garbage • Colonists did not have indoor plumbing so they utilized Privies (out houses). • Several times a year the “waste” material would be layered with dirt and shell to reduce odor • Trash was also disposed in a pit (typically an old well) and routinely layered with shell
Oyster Analysis • There is a gradual change in the kind of oyster shell morphology correlated with the length of time a “colony” existed at a particular site • The early “privy “ layers have predominately sand oyster shell morphology but the newer layers have mid-water shell morphology
Summary • Tobacco farming initiated change in near shore terrestrial communities • Loss of tree cover • Loss of food for animals • Soil nutrient depletion • Erosion • Changes in near shore aquatic communities can also be documented • over use of resources
References • http://www.gmu.edu/bios/bay/cbpo/intro.htm#wetlands • http://www.inform.umd.edu/wetlands/index.html