Presentation on theme: "Lecture 3/4 topics Biomes (what the heck are those?)"— Presentation transcript:
1 Lecture 3/4 topics Biomes (what the heck are those?) Global and localGradients (physical and biological)How plants growProductivity and biomass – importance in production forestry and carbon sequestration
2 Week 2 Learning Objectives You should be able to:Recognize characteristics and general distribution of biomes and what factors influence their spatial coverageDescribe difference between biome based on actual cover and potentialcover (spatially and temporally)Describe various biome/life zone types (globally and locally) and their productivityUnderstand spatial variation (gradients) in forest types (e.g., elevation, latitude, disturbance, temperature, precipitation)Describe basic photosynthesis and plant productivity (gross primary productivity, net primary productivity, differences in plant requirements)Understand the role of vegetation in carbon storage (sequestration)Think about spatial and temporal differences in ecosystems
3 How can we tell different biomes apart? THE CONCEPT OF BIOMESBiome: a major regional community of plants and animals with similar life forms and environmental conditions. It is the largest geographical biotic unit.How can we tell different biomes apart?Generally named after the dominant type of life form (normally vegetation in terrestrial systems), such as tropical rain forest, grassland, or coral reef.
4 Vegetation serves many critical functions: Produces oxygen via photosynthesis2. Role in nutrient cycling and energy flows3. Affects soil characteristics4. Provides wildlife habitat and energy (food) sourceProduces food, wood, fuel and other materials for humans6. Psychologically important to humans, who evolved in direct contact with, and dependence on, vegetation, for food, shelter, and medicine.
5 Much of the work on vegetation classification comes from European and North American ecologists, and they have fundamentally different approaches.North America based on a combination of the following criteria:climate pattern,plant habit,phenology and/or growth form, anddominant species.Europe, classification relies heavily on species composition alone, without explicit reference to climate, phenology or growth forms.
6 Factor for defining biomes Biomes are defined based on factors such as:plant structures (such as trees, shrubs, and grasses),leaf types (such as broadleaf and needleleaf),plant spacing (forest, woodland, savanna),and other factors like climate, soils, etc.Example systemsUdvardy system -1975Bailey systemWorld Wildlife fund – 14 biomes, 852 ecoregions
7 Five Major Biomes Aquatic Forest Desert Grassland Tundra Five Major BiomesAquaticForestDesertGrasslandTundraearthobservatory.nasa.gov
8 8 major biomesPhysical Geography of the Global Environment, 2nd Edition, by H. J. De Blij, et al; 1998
10 WWF systemWorld Wildlife Fund (WWF) developed an ecological land classification system that identified 14 biomes, called major habitat types, and further divided the world's land area into 825 terrestrial ecoregions. This classification is used to define the list of ecoregions identified by the WWF as priorities for conservation.Tundra(arctic)Boreal forests/taiga (subarctic, humid)Temperate coniferous forests (temperate, humid to semi-humid)Temperate broadleaf and mixed forests (temperate, humid)Temperate grasslands, savannas, and shrublands (temperate, semi-arid)Mediterranean forests, woodlands, and shrub (temperate warm, semi-humid to semi-arid with winter rainfall)Tropical and subtropical coniferous forests (tropical and subtropical, semi-humid)Tropical and subtropical moist broadleaf forests (tropical and subtropical, humid)Tropical and subtropical dry broadleaf forests (tropical and subtropical, semi-humid)Tropical and subtropical grasslands, savannas, and shrublands (tropical andsubtropical, and semi-arid)Montane grasslands and shrublands (alpine or montane climate)Deserts and xeric shrublands (temperate to tropical, arid)Mangrove (subtropical and tropical, salt water inundated)Flooded grasslands and savannas (temperate to tropical, fresh or brackish water inundated)
11 In 1975, Miklos Udvardy published a system of 12 terrestrial biomes: Tropical humid forestsSubtropical and temperate rainforests or woodlandsTemperate broad-leaf forests or woodlands and subpolardeciduous thicketsTemperate needle-leaf forests or woodlandsEvergreen sclerophyllous forests, scrub, or woodlandsTropical dry or deciduous forests (including Monsoon forests)or woodlandsTemperate grasslandsWarm deserts and semidesertsCold-winter (continental) deserts and semidesertsTundra communities and barren Arctic desertsMixed mountain and highland systems with complex zonationMixed island systems
12 Based on soil moisture and temperature (14 biomes)
16 Humans are major forces in ecosystem structure and function We consume one third of all terrestrial net primary production,We move more earth and produce more reactive nitrogen than all other terrestrial processes combined,We are causing global extinctions and changes in climate that are comparable to any observed in the natural record
17 Rexford F. Daubenmire, 85, professor emeritus of botany at Washington State University, died August 26, 1995 at his home in Mt Plymouth, Florida. He was one of the nation's foremost authorities on plant ecology.Daubenmire's classification of forest and gressland vegetation in the Pacific Northwest became a standard management tool for both government agencies and the timber industry of the West.Considered radical when introduced in the early 1950's, his classification scheme emphasized the potential vegetation of a site, rather than existing vegetation that often had been altered through fire, logging and grazing. He also made lasting contributions in explaining the environmental restrictions that determine the range of tree species, ecological succession, the migration history of plant species in North America, and the role of fire in shaping many plant communities.
23 Biome subdivisionsLife Zones (e.g., Merriam 1889, Holdridge 1947) based on observed differences in plant and animal communities that change with physical characteristicsTemperature, latitude, elevations, precipitation, etc.Ecoregion- (e.g., Bailey 1995, World Wildlife Fund) ecoregions have similar latitudinal and continental locations and are defined by the processes that produce them. The divisions are more specific than biomes, taking into account biogeographical divisions.
24 Holdrige Life ZonesBased on biotemperature, precipitation, potential evapotranspiration, and humidityearthscienceeducation.org
25 Ecoregions – started by the US Forest Service in 1978, The technique of mapping ecoregions was subsequently expanded to include the rest of North America and the world. In 1993, as part of the Forest Service's National Hierarchical Framework of Ecological Units (ECOMAP).ecoregions were adopted for use in ecosystem management.Robert G. Bailey developed a biogeographical classification system for the United States in a map published in Bailey subsequently expanded the system to include the rest of North America in 1981, and the world in The Bailey system is based on climate, and is divided into four domains (Polar, Humid Temperate, Dry, and Humid Tropical), with further divisions based on other climate characteristics (subarctic, warm temperate, hot temperate, and subtropical, marine and continental, lowland and mountain).
29 b. Physiognomic (or structural – height and spacing of the vegetation) –based on general appearance, dominant life forms, layered structure of plant communitiesi UNESCO – hierarchical systemii. Current US standard (adopted by the Federal Geographic Data Committee (FGDC), and originally developed by UNESCO and The Nature Conservancy), the classification is hierarchical : system, class, subclass, group, formation, alliance, and association. The lowest level, or association, is thus the most precisely defined, and incorporates the names of the dominant one to three (usually two) species of the type. In practice, the levels of the alliance and/or association are the most often used, particularly in vegetation mapping, just as the Latin binomial is most often used in discussing particular species in taxonomy and in general communication.
30 Nature ConservancyOver the past twenty years, The Nature Conservancy has developed a science-based approach to conserving biological diversity. The Conservancy's approach to conservation science relies on the consistent and systematic accumulation, management, and analysis of information on the "elements of biological diversity" specifically the status and location of plants, animals, and ecological communities.National Vegetation Classification SystemThe national vegetation classification system focuses on existing vegetation rather than potential natural vegetation, climax vegetation, or physical habitats. The vegetation types covered in the classification range from the short-lived to relatively stable and persistent plant communities. The classification includes natural, seminatural, modified, and cultural vegetation.Many regional classification schemes have been developed – For example, in the Pacific Northwest (Daubenmire, Franklin and Dyrness) and British Columbia
31 SAF Forest Cover Type for Western U.S. code name201White spruce202 White spruce - paper birch203 Balsam poplar204 Black spruce205 Mountain hemlock206 Engelmann spruce –subalpine fir207 Red fir208 Whitebark pine209 Bristlecone pine210 Interior Douglas-fir211 White fir212 Western larch213 Grand fir215 Western white pine216 Blue spruce217 Aspen218 Lodgepole pine219 Limber pine220 Rocky Mountain juniper221 Red alder222 Black cottonwood - willow223 Sitka spruce224 Western hemlock225 Western hemlock - Sitka spruce226 Coastal true fir - hemlock227 Western redcedar - western hemlock228 Western redcedar229 Pacific Douglas-fir230 Douglas-fir - western hemlock231 Port Orford-cedar232 Redwood
32 Example of US standard classification, through association level System: Terrestrial/Aquatic - (hydrological regime)Class: Woodland - (spacing & height of dominant form)Subclass: Evergreen Woodland - (morphological & Phenological similarity)Group: Temperate Evergreen Needle-leaved - (climate latitude, growth form, leaf form)Formation: Evergreen needle-leaved forest with conical crowns - (mapable units)Alliance (or cover type): Abies lasiocarpa Forest (dominant species)Association (or community): Abies lasiocarpa/Vaccinium scoparium [Subalpine fir/Grouseberry] (subdominant or associated species with similar ecological processes)
33 PNV is the "climax" vegetation that will occupy a site without disturbance or climatic change. PNV is an expression of environmental factors such as topography, soils and climate across an area. Where cover type is a classification of existing vegetation, PNV is a site classification based on climax vegetation. Because the existing cover type at any particular location and time may reflect a vegetation community anywhere along its successional pathway - from seral to climax - the cover type may be the same as the PNV.Terrain-matched refinement of Kuchler's Potential Natural Vegetation (PNV) map have been produced. Kuchler's PNV map was digitized for the conterminous United States, then adjusted to match terrain using a 500 m Digital Elevation Model, 4th Code Hydrologic Unit delineations, and Ecological Subregions (Bailey's Sections). These biophysical data layers were integrated with current vegetation layers, Resource Planning Act's Forest Types and Forest Densities of the United States, and USGS EROS Data Center's Land Cover Characterization database, to develop generalized successional pathway diagrams. Expert regional panels refined the PNV map based on these successional pathways.
34 Why classify biomes/vegetation? Better communication among professionalsBetter understanding of ecosystem interactionsUseful aid for land and natural resource management and monitoring ,U.S. Forest Service, Forest Inventory Analysis (FIA) plots (http://www.fs.fed.us/pnw/fia/)EPA Environmental Monitoring and Assessment Program (EMAP)IUCN Red List for Ecosystems (http://www.iucnredlistofecosystems.org/)Identify the presence of invasive speciesEcosystem health issues – climate change, fire effects
35 Wildlife reintroduction Climate change predictions of distribution How can the classifications be used?CorridorsWildlife reintroductionClimate change predictions of distributionPlant restoration
37 Figure 2. Planning unit cost based on naturalness. Less naturalColumbia PlateauSchloss CA, Lawler JJ, Larson ER, Papendick HL, et al. (2011) Systematic Conservation Planning in the Face of Climate Change: Bet-Hedging on the Columbia Plateau. PLoS ONE 6(12): e doi: /journal.pone
38 No universal classification scheme SummaryNo universal classification schemeBased on various physical, chemical and biological characteristics and assemblagesSome based on current vs. potential life formsSome include humans others do notUsed for planning, management, restoration