Module 2 Ecosystems and Assessment Techniques PDF

Summary

This document details various land and water ecosystems, including rainforests, deserts, grasslands, and freshwater/marine environments. It discusses key concepts like biodiversity, species richness, evenness, and Simpson's diversity index. The document also covers ecological sampling techniques and how to determine biodiversity.

Full Transcript

Module 2 Ecosystems and Assessment Techniques Session Overview 1. Land Biomes and Water Ecosystems 2. Measuring Biodiversity 3. OE 2 (Lec) Diversity Indices 4. Ecological Sampling: Measuring Biotic Components of a System 5. OE 2 (Lab) Article Review: Biodiversity Measurement What is a...

Module 2 Ecosystems and Assessment Techniques Session Overview 1. Land Biomes and Water Ecosystems 2. Measuring Biodiversity 3. OE 2 (Lec) Diversity Indices 4. Ecological Sampling: Measuring Biotic Components of a System 5. OE 2 (Lab) Article Review: Biodiversity Measurement What is a biome? A biome is a group of land ecosystems with similar climates and organisms There are 6 major land biomes and 2 major water ecosystems? LAND (6): RAINFORESTS, DESERTS, GRASSLANDS, DECIDOUS FORESTS, BOREAL FORESTS, & TUNDRA WATER (2): FRESHWATER & MARINE ECOSYSTEMS An area’s biome is determined mostly by its climate (temperature and precipitation) RAIN FORESTS There are 2 main types of rain forests: Temperate Rain Forests and Tropical Rain Forests. TEMPERATE RAIN FORESTS “Temperate”= having moderate temperatures. Northwestern coast of U.S. is a temperate rain forest. Receives more than 300 cm of rain per year. Huge trees: Cedars, Redwoods, Douglas Firs. TROPICAL RAIN FORESTS Found in regions close to the equator Warm and humid all year long. Lots of precipitation. Diverse plant growth. Trees in the rain forest form several layers… Canopy: A leafy roof formed by the tallest trees. Understory: A second layer of shorter trees and vines. Understory plants grow well in the shade formed by the canopy, but the forest floor is nearly dark and only a few plants live there. DESERTS Desert = An area that receives less than 25 cm of rain per year. Some deserts receive NO precipitation at all during one year. Deserts often undergo large shifts in temperature during the course of a day. The scorching Namib desert in Africa cools rapidly after the sun goes down. The Gobi desert in central Asia is cooler and even experiences freezing temperatures in the winter. Organisms that live in the desert must be adapted to the lack of rain and extreme temperatures. – Saguaro Cactus: Stem expands to store water. – Gila monster spends weeks in its cool, underground burrows. – Many other organisms are only active at night when it is cooler. GRASSLANDS Grassland (prairie)= An area that is populated mostly by grasses and other non-woody plants. Receive 25 to 75 cm of rain per year. Fires and droughts are common. Savanna: Grassland that is located closer to the equator than prairies. – Savannas can receive as much as 120 cm of rain per year. – In addition to grass, scattered shrubs and small trees can grow in the savanna. Grasslands are home to many of the largest animals on Earth. Examples: Grazing by these large herbivores helps to maintain these grasslands. DECIDUOUS FOREST Deciduous trees= Trees that shed their leaves and grow new ones each year (Oaks, Maples…) Receive enough rain to support the growth of trees and other plants (at least 50 cm per year). Growing season is 5 to 6 months long. BOREAL FOREST (taiga) – Mostly contains coniferous trees (trees that produce their seeds in cones and have leaves shaped like needles). Ex. Fir, Spruce, Hemlock… – Very cold winters (a lot of snow). – Warm and rainy summers. TUNDRA Tundra = Extremely cold and dry biome. Usually receives NO more precipitation than a desert biome. Most soil is frozen all year long (permafrost) During summer, the top layer of soil thaws, but the rest remains frozen. PERMAFROST o Because rainwater cannot soak into the permafrost, there are many shallow ponds and marshy areas of the tundra during the summer Tundra Plants and Animals POLAR BEAR WOLF REINDEER ARCTIC FOX ARCTIC HARE FRESHWATER ECOSYSTEMS Freshwater ecosystems include streams, rivers, ponds and lakes. Rivers and Streams – Animals adapt to the stream/river’s current (hooks and suckers to cling to rocks, streamline bodies). – Few -plants or algae can grow because of the strong currents. – Animals rely on seeds and leaves to fall in the water as food. River/Stream Organisms Ponds and Lakes – Bodies of standing or still freshwater. – Lakes are larger and deeper than ponds. – Ponds: Shallow enough for sunlight to hit bottom (allowing plants to grow there). – Lakes (and large ponds): Too deep for plants to grow on the bottom, so algae grows and floats on top of water. Pond/Lake Organisms MARINE ECOSYSTEMS Marine ecosystems include estuaries, intertidal zones, neritic zones, and the open ocean. Estuary: Where freshwater of a river meets saltwater of the ocean. Intertidal Zone: The area between the highest high tide line and the lowest low tide line. Organisms here must be able to survive the pounding waves, water level changes, and temperature changes Ex. (barnacles, starfish, snails, clams….) Neritic Zone: The area below the low tide line which extends over the continental shelf. Sunlight passes through this zone, so photosynthesis can occur (plants can grow). Many living things. Coral reefs may form in water is warm. Open Ocean: Separated into two zones: Surface Zone: The first few hundred meters deep of the ocean (where light penetrates). Deep Zone: Below the surface zone (totally dark and home to many BIZZARE organisms). SURFACE DEEP This is Our World: www.smalltownproject.org/ http://news.nationalgeographic.com/news/ Global changes http://www.oceansatlas.org/ http://library.thinkquest.org/ Overharvest Pollution Species invasions http://www.ourworldfoundation.org.uk/polar.jpg Climatic change Land use change Loss of biodiversity - type - intensity Molles 2007 Land Use Change: Madagascar Deforestation, there And here… ~50% of ice-free land transformed by humans. Much fragmented. Land Conversion in Washington by Ecoregion Washington Biodiversity Council 2007 Areas in Cultivation Total Plant Production on Land g C*m-2*yr-1 http://www.ntsg.umt.edu/ecosystem_modeling/spatial/pik-npp/ The “Sixth Extinction”? Current Extinction Rates are 10-100 Fold Higher than Past Loss of Biodiversity: Reasons for Concern - Extinctions are irrevocable - Ethical/moral/religious - Benefits to humanity - Goods: food, fuel, building, medicines, etc. - Services: - Regulating (climate, disturbance, water) - Cultural (Recreation/Education/Aesthetic/Spiritual) Biodiversity Affects Human Well-Being Human Global activities changes Ecosystem services Biodiversity Ecosystem processes Ecosystem Services MEA 2005 Shifts in species can be difficult, expensive, or impossible to reverse. Reed canary grass, Whatcom County Buffelgrass invasion – Sonoran desert (Pennisetum ciliare) http://www.buffelgrass.org/stories.php http://www.desertmuseum.org/invaders/invaders_buffelgrass.htm Source: https://www.youtube.com/watch?v=gYNAtw1c7hI Measuring Biodiversity Key Concepts: Species richness Species evenness Simpson’s Index or abundance of Diversity (D) Metric Normal range Species richness 10-100 species per hectare Species evenness 0.7-0.9 Simpson's index of diversity 0.8-1.0 Species Richness This is a qualitative description… Eg “how many different species can I see?” More species does not always mean more biodiversity…why not? …because there may not be many individuals of each species (evenness) Species Evenness This is a quantitative measurement It is a measure of the abundance of individuals in each species. Percentage cover – the proportion of each quadrat occupied by the species. Abundance Population density – the can be number of individuals per measured… quadrat Species frequency – the proportion of quadrats with the species in it. When both species richness and species evenness increase, there is by definition an increase in BIODIVERSITY. Which field shows the most biodiversity? Species observed Percentage cover Field A Field B Cocksfoot grass 57 38 Timothy grass 32 16 Buttercup 3 14 Clover 3 22 Thistle 1 5 Dandelion 4 5 Total 100 100 Both have the same ‘richness’ ( 6 species), but Field B has greater ‘evenness’; so Field B is more diverse. Simpson’s diversity index (D) is a measure of biodiversity that takes into account richness and evenness. A high value for D is ‘good’ and means the habitat is diverse, species rich, and able to withstand some environmental impact. A low value for D is ‘poor’ and means the habitat is low in species, so a small change to the environment ( eg pollution) would have a serious impact. Looks complex but it’s not..! D = 1 – [ ∑ ( n / N)2 ] n = number of individuals N = total number of individuals Calculating Simpsons diversity index (D) Species observed Percentage cover Field A (n) Field B (n) Cocksfoot grass 57 38 Timothy grass 32 16 Buttercup 3 14 Clover 3 22 Thistle 1 5 Dandelion 4 5 Total (N) 100 100 D = 1 – [ ∑ ( n / N)2 ] Calculating Simpsons diversity index (D) Species observed Percentage cover Field A (n) n/N Cocksfoot grass 57 0.57 Timothy grass 32 0.32 Buttercup 3 0.03 Clover 3 0.03 Thistle 1 0.01 Dandelion 4 0.04 Total (N) 100 D = 1 – [ ∑ ( n / N)2 ] Calculating Simpsons diversity index (D) Species observed Percentage cover Field A (n) n/N (n/N)2 Cocksfoot grass 57 0.57 0.349 Timothy grass 32 0.32 0.1024 Buttercup 3 0.03 0.0009 Clover 3 0.03 0.0009 Thistle 1 0.01 0.0001 Dandelion 4 0.04 0.0016 Total (N) 100 ∑ = 0.4308 D = 1 – [ ∑ ( n / N)2 ] D = 1 – 0.4308 D = 0.5692 Now calculate (D) for Field B… Species observed Percentage cover Field A (n) Field B (n) Cocksfoot grass 57 38 Timothy grass 32 16 Buttercup 3 14 Clover 3 22 Thistle 1 5 Dandelion 4 5 Total (N) 100 100 D = 1 – [ ∑ ( n / N)2 ] Field B (D) Species observed Percentage cover Field B (n) n/N (n/N)2 Cocksfoot grass 38 0.38 0.1444 Timothy grass 16 0.16 0.0256 Buttercup 14 0.14 0.0196 Clover 22 0.22 0.0484 Thistle 5 0.05 0.0025 Dandelion 5 0.05 0.0016 Total (N) 100 ∑ = 0.243 D = 1 – [ ∑ ( n / N)2 ] D = 1 – 0.243 D = 0.757 Conclusion: D for Field A = 0.5692 D for Field B = 0.757 “Field B has the higher diversity index, so has more species richness AND evenness. It would be more resistant to any environmental damage or change.” OE 2 (Lec) Diversity Indices 1 2 3 Upload the Field Compute the Explain/Interpret Worksheet Diversity Indices the results of the given data Due: Sep 9, 2024, 11:59 PM Ecological Sampling What is a sample? – “A portion, piece, or segment that is representative of a whole” Why do we sample? – it is usually impossible to measure the whole Assumptions… That the sample is representative of the whole. It is necessary to take enough samples so that an accurate representation is obtained. It is important to avoid bias when sampling. Sampling Methods Transects and Plants and Non-motile Quadrants animals Capture –Mark- Recapture Lincoln Index Small animals Aerial Large trees and animals observations Sampling along Transects Samples taken at fixed intervals Set up along an environmental gradient (e.g. high to low on a mountain) Line Transect Method A measured line laid across the area in the direction of the environmental gradient All species touching the line are be recorded along the whole length of the line or at specific points along the line Measures presence or absence of species Used to measure coverage and abundance of plants or animals A grid of known size is laid Quadrats out and all the organisms within each square are counted. Belt Transect Method Transect line is laid out and a quadrant is placed at each survey interval Samples are identified and abundance is estimated – Animals are collected – For plants, a percent coverage is estimated Data collection should be completed by an individual as estimates can vary person to person Lincoln Index Capture-Mark-Recapture – Animals are captured, counted, tagged and released. – After a period of time another capture occurs. – Previously tagged animals are counted and unmarked organisms are marked. – Abundance is calculated using the following formula: Measurements Sampling methods measure – Density – Coverage – Frequency – Biomass – Diversity Density (D) The number of individuals per unit area – D=ni/A ni=number of individuals for species i – Eg. 10 dandelions/m2 A=the area sampled Relative density i (Rdi) (could be the volume V) – The Density of species i, Di, Divided by the sum of all the densities of the other species sampled – Rdi=Di/ D – Eg. 10/5+8+16 Coverage (C) The proportion of ground that is occupied or area covered by the plant/species – Ci=ai/A ai=the area covered by species i Relative coverage A=the total area – The Coverage of species 1, Ci, divided by the sum total of the coverage of the other species sampled Frequency (f) The number of times a given event occurs – Eg. the number of quadrants that contain maple trees as a ration of all the quadrants – fi=ji/k ji=number of quadrants with species i Relative frequency k=total number of quadrants – The frequency of species i relative to the sum total of the frequencies of the other species found Biomass (B) Can be calculated by measuring the mass of the individuals per unit area – B=  W/A – More appropriate measure than density or frequency when Number of individuals in hard to determine Photosynthesis and carbon fixation, energy and nutrient transfer are more dependent upon biomass than the total number of individuals Biomass Measurement Methods Fresh or wet weight – Used when organisms are alive Dry weight – Used when the water content varies greatly – Oven dry at 105oC to remove water Ash-Free Weight – Used when inorganic content varies greatly – Oxidize at 500oC until only inorganic ash remains Diversity The measure of variety of an ecosystem Consists of 2 components – The number of different species or the richness of species in a specific area – The relative abundance of the individuals of each species in a specific area Simpson's Diversity (D) Measures species richness D=N(N-1) D=Diversity  n(n-1) N=total number of organisms of all species found n=number of individuals of a particular species If D is high the area may be a stable ancient site. Low D may suggest pollution, recent colonization, or agricultural management Forest Measurements What are forest measurements? “How-to-do-it” for tree overstory, i.e.,timber volume, tree form, growth, cull factors, mortality, etc. Deals with direct measurements, sampling, and prediction There are still many measurement problems for which no perfect solutions exist Why measure forest resources? Forest management requires knowledge of the location and their current features The role of measurements is to supply the numerical data required to make management decisions Accurate measurements allow scientifically sound management decisions being made Types of Measurements Direct measurements – Tree height – Tree diameter Sampling – A portion of the entire resource - expand to characterize entire resource Prediction – Those resources, such as tree volumes, not easily measured Scales of Measurements Nominal scale – Numbering objects for field identification, e.g., tree number, plot number Ordinal scale – Expressing rank or position in a series, where rank has meaning, e.g., tree crown classes, lumber grades, site quality classes Interval scale – A series of graduations marked off at uniform intervals from an arbitrary origin, e.g., temperature Ratio scale – A series of graduations marked off at uniform intervals from an origin of absolute zero, e.g., tree height, volume, length of trail, amount of habitat Standard Practices Abbreviations and symbols Significant digits and rounding off – Don’t record more significant digits than were observed – Ignore the 5 when the digit preceding is an even number. Conversely, if the digit preceding is an odd number? – Rounding off should be carried at least two places beyond that of the final rounded figures Conversions between metric and English units Natural Resource Measurements Forestland Sampling units: fixed- Features measured: trees radius plots, variable radius plots, strips Sampling schemes: Measures: timber systematic sampling, volume, wildlife habitat, stratified random forest density sampling Rangeland Features measured: Sampling units: small grasses, forbs, shrubs square plots Sampling schemes: Measures: weight of systematic sampling, herbage, grazing capacity, stratified random range condition and sampling trend Wildlife Features measured: animals, Sampling units: plots, strips, habitat areas Measures: animal presence, Sampling schemes: direct animal species richness, census, indirect census, animal populations, wildlife mark-recapture techniques habitat suitability Water Resources FEATURES SAMPLING UNITS: SAMPLING SCHEMES: MEASURES: WATER MEASURED: WATER WEIRS, FLUMES, WATERSHEDS, QUANTITY, WATER CURRENT METERS STREAM REACHES QUALITY Recreation Sampling units: visitor Features measured: days, vehicles, water people usage Measures: recreation Sampling schemes: quality, recreation complete registration, opportunity, visitor self registration, surveys satisfaction Presentation and Submission Due: Sep 9, 2024, 7:00 PM Transects and Quadrants 1. Tayam Lincoln Index 2. Flores Aerial observations Density 3. Castor Coverage 4. Gabiosa L. Frequency OE 2 (Lab) Article 5. De Leon Biomass Diversity 6. Desamero Review: Biodiversity Direct measurements 7. Alvarez Measurement 8. Bungaos Sampling Prediction 9. Aguilar Forestland 10. Gonzales Rangeland 11. Mandapat Wildlife 12. Bartolome Water Resources 13. Gabiosa, N. Recreation

Use Quizgecko on...
Browser
Browser