docEcoregion Mapping
download 
Report Transcription
Ecoregion Mapping
Ecoregion Mapping ENSC502 January 10, 2006 What’s an ecoregion? • Must have something in common • More in common within the same region than between a region and others • Q: geographically contiguous? ENSC502 January 10, 2006 What do we want to use ecoregions for? • Protected area designation • Applying norms and standards like building codes • Capability to support some human activity • Flow modelling, e.g. carbon cycle • Agricultural equivalency or ability to support a given crop ENSC502 January 10, 2006 How big is an ecoregion? • “Region” is a generic term • Hierarchical models allow subdivisions depending on the scale you’re interested in ENSC502 January 10, 2006 What can we use to define them? • Usually, “permanent” features such as climate, natural plants • How do we cope with climate and plant change? • What about degree of human development? • Some use taxonomic systems ENSC502 January 10, 2006 Basic idea of why ecoregions exist • Organisms adapt and co-evolve to fit their conditions • Each organism or community spreads as far as conditions allow them to do – May be external conditions or competition • Genetically unrelated organisms may fit into same niche, so ecoregions not related to taxonomy ENSC502 January 10, 2006 World Wildlife/National Geographic • Use terms derived from taxonomic regions • Originally served to figure out migration and colonization patterns of plants and animals • “Palearctic”, “Afrotropical” etc. • See http://www.nationalgeographic.com/wildwo rld/terrestrial.html (sorry, their map server is down for January!) ENSC502 January 10, 2006 Ecoregions as domains • Idea that climate is the major controlling factor to organism location ENSC502 January 10, 2006 Polar domain • Polar: icecap, tundra, subarctic, each mountainous or not • Basis of divisions: plant development in summer – How well can plants use what energy is available? • Annual energy range greater than daily energy range • Dry, most ppn in summer ENSC502 January 10, 2006 Polar plants • Tundra (grass, sedge, lichen, willow shrubs) • Lichen-birch woodlands • Needleleaf forest ENSC502 January 10, 2006 Humid temperate domain • • • • • • • • Subtropical Hot continental Warm continental Marine Prairie Mediterranean Basis: importance of winter frost for plants Strong seasonality ENSC502 January 10, 2006 Humid temperate plants • Mix of broadleaf deciduous and needleleaf evergreen ENSC502 January 10, 2006 Humid tropical domain • • • • Savanna Rainforest Monsoon Basis of division: winter temperature and rainfall • Energy flux is much greater daily than annually ENSC502 January 10, 2006 Dry domain • • • • • • Hot desert Hot steppe Temperate desert Temperate steppe Basis of divisions: rainfall seasonality Short and mid grasses, shrubs and woodlands locally • Crops usually require irrigation or other water mitigation (summerfallow, for example) ENSC502 January 10, 2006 ENSC502 January 10, 2006 Next lower (more detailed) mapping level • Systems of mapping start diverging here • Baily: US Forest Service – Provinces depend on vegetation macrofeatures (structure) – Interaction of plants with microclimate, landform, soil, fauna – Names related to specific locations: Bering tundra – Mainly descriptive ENSC502 January 10, 2006 CEC (NAFTA environmental) • Mandate: ecology including human activity as part of ecosystem • Need to understand ecoregions that might impact on sustainability of economic activity • Want a system expressing problems linked to local ecosystems that might need to be prevented, remediated. ENSC502 January 10, 2006 CEC system continued • Interplay of geology, landform, soil, vegetation, climate, wildlife, water, settlement, industry • Mapping uses overlays of soil maps, landform maps, veg maps, etc.: less hierarchical • Ecotones are left to the mapper’s judgement ENSC502 January 10, 2006 What is a CEC ecoregion? • An area of land with a distinctive combination of actually occurring characteristics • Abstracted mapping from reality, not a theoretical framework • Levels of increasing detail: I at most general, down to IV as needed ENSC502 January 10, 2006 CEC ecoregion titles • Fit into “polar domain: arctic cordillera, tundra, taiga • Fit into humid temp domain +/-: Hudson plains, northern forests, marine west coast forests, Mediterranean California, etc. – Note sometimes mainly called by climate, other times by location, others by vegetation. ENSC502 January 10, 2006 Environment Canada mapping http://www.ccea.org/ecozones/intro.html ENSC502 January 10, 2006 EnCan • An ecozone is an area where organisms and their physical environment endure as a system • 15 level I zones • Include landforms and climate • Plants • Wildlife • Human activities • Similar to CEC but more adapted to Canada alone ENSC502 January 10, 2006 Canadian system contd • Hierarchical subdivision • Ecozones, e.g. prairies – Ecoregions, e.g. fescue grassland • Ecodistricts, local ENSC502 January 10, 2006 How Canadian zonation system is used • Reporting: soil degradation, water contamination, similar items • Monitoring – Baseline ecosystem properties and changing conditions are recorded – Permanent sample plots set up in each ecoregion • Locating protected sites – One national park in each ecoregion, terrestrial and marine is the goal ENSC502 January 10, 2006 ENSC502 January 10, 2006 Mapping from satellite imagery • Less reliant on permanent features, can get instantaneous view of what is there • Can include dynamic features ENSC502 January 10, 2006 Satellite contd • Major subdivision: seasonality – Each region has similar onset of greenness, magnitude of max vegetation density, growing season duration • Add overlay of terrain, land-cover ENSC502 January 10, 2006 Satellite contd. • “Continuous field” mapping – Value of 0-100 for forest cover, temperature range, etc. – Individual users can then specify how they want to “harden” the classification for their needs • Maps for specific years can highlight changes or variability ENSC502 January 10, 2006 Raw data to overlay ENSC502 January 10, 2006 Seasonally-distinct classes for 1990 http://ciesin.columbia.edu/docs/005-347/005-347.html ENSC502 January 10, 2006 AB Natural Subregions • Similar system but tied to AB physical properties • AB has ppn gradient from SE to NW, topographical gradient from W to E, and temperature gradient from S to N ENSC502 January 10, 2006 ENSC502 January 10, 2006 AB subregions • Each of the natural subregions is described in terms of ecosites • Ecosite is a property at a location, defined as a point on a nutrient vs. wetness gradation • Characterized by an association of species • Used to evaluate potential damage under activity scenarios, or remediation prescriptions • Not a map per se, a series of tables and descriptions. ENSC502 January 10, 2006 Relating satellite maps to AB subregions ENSC502 January 10, 2006 • The image colours are an overlay of average seasonal vegetation density, degree of seasonality, and greenup time for each year • Some years correspond well to subregions, others do not • Provides possibility of mapping variability ENSC502 January 10, 2006 Summary • Ecoregions have a lot of different terminology • Most systems are hierarchical • How mapping is done depends on purpose in mind and technology/data available ENSC502 January 10, 2006 Summary Defined by: ¾ Potential of long-term actual vegetation composition as influenced by ¾Physiography ¾Substrate and soils ¾Climate: temperature and precipitation means and extremes ¾ Sometimes includes degree and type of human alteration ENSC502 January 10, 2006 Summary Useful for: ¾ Designating protected areas ¾ Defining area over which parameters apply in modelling ¾ Evaluating agroforestry potential ¾ Assessing potential impacts of natural or human induced change ENSC502 January 10, 2006
