* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Forest and Range Ecology
Survey
Document related concepts
Biogeography wikipedia , lookup
Restoration ecology wikipedia , lookup
Molecular ecology wikipedia , lookup
Introduced species wikipedia , lookup
Latitudinal gradients in species diversity wikipedia , lookup
Occupancy–abundance relationship wikipedia , lookup
Biological Dynamics of Forest Fragments Project wikipedia , lookup
Island restoration wikipedia , lookup
Ecological fitting wikipedia , lookup
Biodiversity action plan wikipedia , lookup
Theoretical ecology wikipedia , lookup
Reconciliation ecology wikipedia , lookup
Transcript
Outline •Discuss definitions and components of range and forest ecosystems •Introduction to biological organization •How and why do we classify organisms? •What is a species? Why do we need to identify them? •Interaction with environment: variability within species •Examples Definitions of range: •‘Those areas of the world, which by reason of physical limitations, low and erratic precipitation, rough topography, poor drainage, or cold temperatures, are unsuitable for cultivation and which are a source of forage for free-ranging native and domestic animals, as well as a source of wood products, water and forest wildlife'. (Stoddart et al. 1975). Society for Range Management: •Vegetation is predominantly grasses, graminoids, forbs or shrubs; managed as a natural ecosystem. •If plants are introduced they are managed similarly. •Rangelands include natural grasslands, savannas, shrublands, many deserts, tundras, alpine communities, marshes, and meadows. Forest: • Area of 0.5-1 Ha, 10-30% tree canopy cover, trees >2-5 m at maturity • 10% stocked by trees, and not subject to uses preventing normal tree regeneration (eg. Heavy grazing, mowing) • “Area managed for production of timber and other forest products, or maintained as wooded vegetation for such indirect benefits as protection of catchment areas or recreation”. (Lund 1998) Range management: Rangeland management is ‘the science and art of optimizing the returns from rangelands in combinations that are most desired by and suitable to society through the manipulation of the range ecosystem’ (Stoddart et al. 1975) Range management: Applies knowledge from range science and practical experience. • Protection and improvement of resources (ie sustainability). • Optimum production of goods and services. • “The overriding goal is rangeland resource rehabilitation, protection, and management for multiple objectives including biological diversity, preservation, and sustainable development for people." (Heady and Child 1994) Components of Ecosystems • Abiotic: • Biotic: Processes of Ecosystems • • • • • • Carbon fixation (productivity) Nutrient cycling Water cycling Energy transfer between trophic levels Materials transport (erosion, deposition) Decomposition (cycling) Forests • What processes, components, services are important in forests? Rangeland • What processes, components, services are important in rangelands? Classifying Biotic components • How do we classify organisms? – – – – – Trophic levels (ecosystem roles) Life form (e.g. plant growth forms) Life history (e.g. length of life) Phylogeny (evolutionary relationships) Taxonomy Classifying Biotic components • Why do we classify organisms? – To understand ecosystem functioning – To understand relationship of organisms to environment and each other, and predict responses. Species • What is a species? – Many definitions (25 +) – Some definitions based on characteristics of organsims, some based on reproduction, some based on phylogenetic descent. – 3 main ideas: • Morphological • Biological (BSC) • Evolutionary/phylogenetic Species Concepts • Morphological: group of animals or plants sharing one or more distinct characters. • Biological: Similar natural populations that are reproductively isolated from other populations. • Phylogenetic: a cluster of individuals with a common evolutionary ancestry. “Units of evolution”. Species Concepts • Species definition combines morphology, breeding, and habitat. • Taxonomic species: combines mainly morphology and BSC. Somewhat arbitrary and distinctions are not clear. • Composed of “ecologically important subunits”? Or is variation continuous? (ecotypes or ecoclines) Species Concepts “A species is a group of individuals, which, in the sum total of their attributes, resemble each other to a degree usually accepted as specific, the exact degree being ultimately determined by the more or less arbitrary judgement of taxonomists” Why are species important? Why are species important? • We consider that “species” respond as units to environmental conditions (=ecotypes?). • Considered to be “units of evolution” – stage where biological discontinuity takes place. • “Specieshood” related to genetic and ecological differences (even if not perfectly). Species richness =simple measure of biological diversity. • Endangered species: populations with distinct characteristics (ecological, reproductive, and morphological). In danger of extinction, are different enough from similar groups to warrant salvage. Species in range and forest ecology Species in range and forest ecology • May use species-based measures to assess health, identify potential land uses, predict habitat quality,etc. • Species composition related to community characteristics. • Economically important species (e.g. timber trees, good forage species) Species in range and forest ecology: summary • “Species” difficult to precisely define. • All definitions are somewhat arbitrary. • Variation in response to environment within given species. • We need and want to classify organisms, so “species” still used. • Even though imperfect, taxonomic species ID can and is for assessing ecosystem characteristics, understanding community dynamics, and making management decisions. Species in range and forest ecology: summary Variation in species (ch. 3) • Substantial variation within taxonomic species: heritable, adaptive characters (Turesson) • e.g. hawkweed in Sweden (ecotypes): – – – – Three habitats (woodland, field, dune) Differ in traits: habit, leave shape, dormancy Traits maintained when grown in greenhouse All groups interfertile • Similar experiment in California (Clausen et al 1940). Variation in species • “common gardens” at Stanford, Mather (Midelevation Sierra Nevada), and Timberline (3000m elevation) • Grew 60 different species collected from a range of sites from coast to eastern slopes • Potentilla glandulosa ecotypes (subspecies) differ in growth form, frost and disease and survival in different gardens (see textbook Ch. 3) Variation in species • Additional examples: readings – Saltgrass frost tolerance: Crop Science 43:2142-2147 – Norway Spruce altitudinal ecotypes: Functional Ecology 12:573-590 Subspecies or different species? • Pinus contorta – three subspecies. Contorta not fire adapted (shore pine). Latifolia (rocky mountain lodgepole) fire dependent; dominance in landscape and proportion serotinous cones related to fire frequency. Murrayana (sierra lodgepole) fire sensitive, but early after-fire coloniser. Not serotinous. • Pinus ponderosa and Pinus jeffreyi. Differ in resin chemistry and habitat (elevation). Are sympatric at midelevation, and hybridize. • Ord’s kangaroo rat in Alberta – hibernate. Don’t hibernate anywhere else. Is this peripheral population worth saving as a distinct taxon?