Transcript Historical Lanscapes and Legacies
Historical Landscapes and Legacies
Why study historical landscapes?
(from Delcourt et al. 1983)
Human Scale Human Scale (from Bissonnette 1997)
Why study historical landscapes?
1) Broad-scale ecosystem processes can be slow and/or infrequent.
Why study historical landscapes?
1) Ecosystem processes can be slow and/or infrequent.
2) To improve our understanding of ecosystem stability and resilience – natural variability.
Ecological Stability and Resilience
Ecosystems:
•
closed vs. open
•
deterministic vs. stochastic
•
homogeneous vs. heterogeneous
Natural Variability • Understanding and maintaining dynamic ecosystems.
• Spatial and temporal variation in ecological conditions, that are relatively unaffected by people, within a period of time and over a geographical area (Landres et al. 1999).
• Assumptions: 1) Disturbance is an natural part of any ecosystem, 2) Ecosystems are resilient to disturbance, 3) Maintaining ecosystem types maintains ecosystem integrity, over broad spatial scales.
Why study historical landscapes?
1) Ecosystem processes can be slow and/or infrequent.
2) To improve our understanding of ecosystem stability and resilience.
3) To improve our predictions of future ecosystem states.
Complex Systems Theory • • Ecological systems are complex and often dependent on initial conditions.
Legacies – structures that affect ecosystem functioning long after disturbance event.
Message from a Mountain - Franklin and MacMahon (2000) Extant Theory Predicted • Slow • Uniform encroachment by hardy species • Ecological Succession Ecosystem Recovery Actually Occurred • Rapid • Via diverse pathways: largely nucleation • Largely due to legacies
Biotic Legacies – the types, quantities, or patterns of organisms and biotic structures that persist from the pre-disturbance ecosystem.
Biotic Legacies of Mt. St. Helens:
Biotic Legacies – the types, quantities, or patterns of organisms and biotic structures that persist from the pre-disturbance ecosystem.
Biotic Legacies of Mt. St. Helens: • rhizomes, roots, seeds, and spores below ground • pocket gophers and deer mice below ground • tree saplings and shrubs below snow • invertebrates and amphibians in ponds • snags and downed logs
Abiotic Legacies – physical modifications of the environment that may result from disturbance.
Abiotic Legacies of Mt. St. Helens:
Abiotic Legacies – physical modifications of the environment that may result from disturbance.
Abiotic Legacies of Mt. St. Helens: • ash deposition • mud slides and erosion channels
Why study historical landscapes?
1) Ecosystem processes can be slow and/or infrequent.
2) To improve our understanding of ecosystem stability and resilience.
3) To improve our predictions of future ecosystem states.
4) To provide background for natural resources management decisions.
Ecological Restoration • • Requires defensible baselines.
Baselines are used to: 1) assess the need for restorative treatments, and 2) to evaluate their success.
Why study historical landscapes?
1) Ecosystem processes can be slow and/or infrequent.
2) To improve our understanding of ecosystem stability and resilience.
3) To improve our predictions of future ecosystem states.
4) To provide background for natural resources management decisions.
5) General interested in where we have been.
Ways to Study Historical Landscapes • The Environmental Record • Lake Sediments, Bogs, Forest Hollows • Tree Cores • Packrat middens • Field evidence • The Written Record • Land Surveys, Wills, Tax Rolls • Aerial Photos, Maps, Landscape Photos • Laws, Diaries, Artwork
Ways to Study Historical Landscapes • Lake Sediments, Bogs, Forest Hollows
Palynology – species, not communities, migrate (Davis 1981)
Ways to Study Historical Landscapes • Tree Cores
Dendrochronology – Southwestern fire regimes (Swetnam and Baisan 1996) • Southwestern Ponderosa Pine experience high frequency, low intensity fires • High intensity stand replacing fires rare • Fire frequency climate driven • Fire suppression coincided with Anglo American settlement
Ways to Study Historical Landscapes • Packrat middens
Packrats middens – vegetation migration along elevation gradients (Thompson 1990)
Ways to Study Historical Landscapes • Field evidence
Ways to Study Historical Landscapes • Land Surveys, Wills, Tax Rolls
Township 48 N Section corner Quarter corner Meander corner # # # 1 mile 4th Principal meridian Township 1 N Baseline
Land Surveys – some uses and insights… • Determining the ecological niche of tree species (Whitney 1982) • Determine fire regime in even-aged systems (Radeloff et al. 1999) • Baseline in documenting land cover change (White and Mladenoff 1996) • Baseline for ecological restoration (Parker 1997)
Ways to Study Historical Landscapes • Aerial Photos, Maps, Landscape Photos
Maps, Aerial Photos – White and Mladenoff (1994) Presettlement (1860s) – Public Land Surveys Process: Broad-scale human disturbance Post-settlement (1930s) – Wisconsin Land Economic Inventory Process: Forest succession Current (1989) – Color infrared Aerial photos
Ways to Study Historical Landscapes • Laws, Diaries, Artwork
“The soil is a red loam, supporting a heavy forest of oak, pine, hickory, and maple, and interspersed with occasional patches of highland prairie.”
- Henry Rowe Schoolcraft’s description of the lower Fox River in Wisconsin.
Artwork - Mt. Trumbull, AZ (Moore et al. 1999) 1870 sketch by artist, H.H. Nichols Mid-1990s photograph
All Data Sources have Strengths and Limitations!!!
• Environmental Record • Pollen of some species over/under represented due to differences in dispersal or preservation.
• Extreme events can erase a previously recorded event.
• Written Record • Bias or self-interest of observer.
• Knowledge of the observer.
• Context of the statement.
Multi-data Source • Moore, et al. (1999) use historical data to determine reference conditions in Southwestern Ponderosa Pine Forests: Fire regime Dendrochronology Vegetation composition Pollen Data Vegetation structure Dendrochronology, Historical records & photos Pack rats
All Data Sources have Strengths and Limitations!!!
P =
f
(Production, Dispersal, Preservation, Identification)
Some important things we have learned studying historical landscapes • Ecosystems are NOT static, deterministic, homogenous, or closed.
• Species, not communities, migrate latitudinally and elevationally with climate change.
• Biotic and abiotic legacies from disturbances can have prolonged effects on ecosystem composition, function, and structure.
• Human land use can have large and persistent affects on vegetation patterning and stream quality.
• Reconstruct disturbance regimes.
• And much, much more….
Ecologists Landscape Architects Climatologists Historical Ecology Historians Managers Geographers
References Davis, M. B. 1981. Quaternary history and the stability of forest communities. Pages 132 – 153
in
West, D. C., H. H. Shugart, and D. B. Botkin, editors. Forest Succession. Springer Verlag, New York, New York, USA.
Bissonette, J.A. 1997. Wildlife and landscape ecology. Springer, New York, New York, USA.
Delcourt, H. R., P. A. Delcourt, and T. Webb. 1983. Dynamic plant ecology: the spectrum of vegetation change in space and time. Quaternary Science Review 1:153-175.
Egan, D., and E.A. Howell. 2001. The historical ecology handbook: a restorationist’s guide to reference ecosystems. Island Press, Washington, D.C., USA.
Franklin, J.F., and J.A. MacMahon. Messages from a mountain. Science 288:1183-1184.
Landres, P. B., P. Morgan, and F. J. Swanson. 1999. Overview of the use of natural variability concepts in managing ecological systems. Ecological Applications 9:1179-1188.
Moore, M.M., W.W. Covington, and P.Z. Fule. 1999. Reference conditions and ecological restoration: a southwestern ponerosa pine perspective. Ecological Applications 9;1266 1277.
References (cont.) Parker, L. 1997. Restaging an evolutionary drama: thinking big on the Chequamegon and Nicolet National Forests. Pages 218-219
in
forestry for the 21 st Kohm, K.A., and J.F. Franklin, editors. Creating a century: the science of ecosystem management. Island Press, Washington, DC, USA. Radeloff, V. C., D. J. Mladenoff, H. S. He, and M. S. Boyce. 1999. Forest landscape change: The northwest Wisconsin Pine Barrens before European settlement and today. Canadian Journal of Forest Research 29:1649-1659.
Russell, E.W.B. 1997. People and the land through time: linking ecology and history. Yale University Press, New Haven, Connecticut, USA.
Thompson, R.S. 1990. Late Quaternary vegetation and climate in the Great Basin Pages 200 239
in
Betancourt, J.L., T.R. Van Devender, and PS. Martin, editors. Packrat middens: the last 40,000 years of biotic chance. University of Arizona press, Tucson, Arizona, USA.
White, M.A., and D.J. Mladenoff. 1994. Old-growth forest landscape transitions from pre European settlement to present. Landscape Ecology 9:191-205.
Whitney, G. G. 1982. Vegetation-site relationships in the presettlement forests of northeastern Ohio. Botanical Gazette 143:225-237.