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Biological Sciences
Marc Cadotte

DEFINITIONS Lecture Term Definition 24 Imperiled Critically endangered, mostly fish, and angiosperms Passenger pigeon High abundance to extinct Conservation biology Integreative discipline applies principle of ecology to conservation of biodiversity and affects maintenance, loss and restoration of biodiversity. For ex: stabilization of red-cockaded woodpecker required cont. from several disciplines (law, polisci, and socio) ESA (eco soc. of Am) 1915: disagreement about mission: ecologists or conservers? 1917: a wing within ESA was Com of preserv of natural cond. 1946: renamed to ecologists union and took direct action to save threatened natural areas 1950: renamed to nature conservancy Objectivity Collection and interpretation of data without bias based on scientific method Alwyn Gentry Identified, classified and mapped immense diversity in Central and South America and witnessed species extinction and deforestation Threats to biodiversity Habitat degradation, invasive species and overexploitation Habitat degradation reduce quality of habitat for many, but not all species Habitat fragmentation Breaking up of continuous habitat into habitat patches in a human dominated landscape Habitat loss Conversion of ecosystem to another use Invasive species Non-native, introduced species that sustain growing pop and have larger effects on communities Order of chaos Habitat fragmentation  habitat degradation  more vulnerable to invasive species Bycatch Species of conservation concern: marine mammals, birds and turtles U.S. endangered species Indentifies and protects ciritical habitat act Ex situ Endangered species and moving them to an off-site conservation to a wild area or within care of humans. Very expensive and had limited success in restoring wild populations (SMALL POP) Fine filter Genes/populations/ species Coarse filter Landscape/ecosystem/habitat : protects many species at once Core natural areas Conservation of biod and ecological intregity. Uncut by roads and trails, not all areas qualify Buffer zone Large areas with less stringent controls on land use but are partially 23 compatible with species’ resource requirmnts 80% endemic Reserve conf Largest pop, habitat for species, largest area Surrogate species Protecting one species result in protection of another w/ overlapping habitat req: red-cockaded woodpecker Flagship species Charismatic organism people give protection ; giant panda Umbrella species Assume protection of habitat will protect other species with similar habitat req. have large ranges : grizzly bear, specialized habitats (red- woodpecker) , easy to count (butterflies) Biogeography Species comp and diversity across geo locations South NZ Dominated by birch trees and small leaves , branch of divaricating understory shrubs have a zigzag (20 species) North NZ Dominated by emergent conifers, flowering trees, has kauris one of largest species , and ancient ferns fiddleheads Regional species pool All the species in a region (gamma diversity) Global biogeography Controlled by geographic area & isolation, evolutionary history (tropical regions have longer history being temporally stable) global climate(higher lat, severe climactic conditions such as ice ages increase extinction rate and hinder speciation) and productivity (species div higher in tropics->higher produc->larger pop sizes-> lower extinct rates) Alfred russel Wallace Study of species distribution across large spatial scales/ in 1862, he went to the Malay archipelago, singapore and collected beetles. Noticed mammamls of philipines were more similar to Africa (5,500 km away) than those of new guinea (750 km). Wallace’s line Separation between two faunas. Noticed: earth’s mass can be divided into 6 geographic regions based on terrestrial animals, gradient of species diversity with latitude ( diversity greatest in tropics and decreases towards poles) Great biotic interchange NA part of laurentia SA part of gondwana. Came together 3-6 ma. Movement of species from one continent to another Vicariance Evolutionary separation of species due to barrier – c.d. Ratites Large flightless birds whose ancestor came from gondwana Species richness Migration, speciation and extinction. increases with area, decreases controlled by with distance , balance between immigration and extinction Cradle(birth of species) Tropics have higher rates of speciation than temp and polar Museum (preservation Tropics have lower extinction rates than temp or polar regions of species) Species diversity in High species diversity + low extinction of tropics due to large area, tropics high pop and stable temp Regional biogeography Species diversity increases with area and decreases by distance due to balance b/w immigration and rates Species-area Species richness increases with increasing larea sampled. Great Britain relationship has the largest area therefore more species Species-area curves S=zA + c Channel Islands (steeper slopes, higher z, greater variation in species richness) and French mainland Equilibrium theory of Number of species on island depends on balance b/w immigration island biogeography rates and extinction rates Simberloff and Wilson Worked with mangrove islands in florida: island closest to source (1969) recovered species richness within 140 days, island farthest from source didn’t recover after a year Study the case study 22 Ecosystem function Physical, chemical, and biological processes that contribute to maintenance of ecosystem: carbon cycling, nutrient cycling, productivity, stability, decomp Ecosystem services Benefits people gain from ecosystems like provisioning(water filtration), regulating(waste), cultural, supporting, pollution filtration, food production, wood, pollination, erosion control biodiversity 1994: David Tilman and Stability, ability to maintain after disturbance. In Minnesota, plots w/ John Downing, diff number of plant species. As number of species increased, their Nature “Biodiversity ability to resist disturbance was better. MORE SPECIES=BETTER and stability in BOUNCE BACK CAPABILITY grasslands” Ecosystem 1994: Shahid Naeem Talks about productivity. Ability to provide living material. Has an function Nature “Declining ecotron where you control env. Conditions such as temp, humidity, Biodiversity can Alter the light and grow diff mini ecosystems. Number of species determines how well ecosystem functions . Different heights of plants. Greater % Performance of change in % cover allowed for higher diversity ecosystems” Michael Selection effect When building a fake ecosystem, you pick any of the species and put Houston: them in there. As you increase number of species in your fake hidden ecosystem, you have a large chance of selecting a keystone species= treatments higher ecosystem productivity in ecological experiments Complimentary effects All plants are growing at same height, competing for same sunray, same root depth, competes for same soil (monoculture)k. When you mix different species, there are tall species that use top light and species growing to diff. root depths partition resources Functional trait Feature of organism relates to its function. Determines organisms’ response to pressures, and/or its effects on ecosystem processes . ex, leaf C:N ratio Functional diversity Different functional roles in an ecosystem, combining multiple traits together into single diversity Phylogenetic diversity Evolutionary relatedness of species present in area Genetic diversity Heritable variation in populations which is created, enhanced, or maintained by evolutionary forces 21 Range size Extent of occurrence and area of occupancy. Many species occupy small ranges EOO ( extent of Stuff inside polygon occurance) AOO (area of Sum of occupied grid squares occupance) Establishing Range wide occurences Maxent modelling for predicting distribution of species, habitat data species such as climate and elevation distributions Maxent modelling provides habitat data such as climate and elevation Marginal occurences EOO (extent of occurrence) : area within convex polygon AOO ( area of occurrence) : sum of occupied grid squares Habitat distributions From bathymetrical data to habitat map developed Why care about range Many species occupy small ranges size? - Rarity: low abundance for small range sizes, risk of extinction, Why the range margin? Environmental factor : abiotic ( climate) Biotic ( competition or hebivory) Variation in individual or population fitness : Edge populations may suffer from: - reduced fitness (not always) - decreased abundance (not always) . “abundant center hypothesis” range margin is often undersampled and doesn’t always correspond to poor env. Mating system and Selfers may have smaller or larger ranges than outcrossers range size 20 Trait Well defined, measurable property of organisms at ind level Functional groups Groups of species withj similar functional traits. For ex, plants in the Fabaceae family host symbiotic bact that convert atmospheric nitrogen into nitrate, which is usable by plants. These plants belong to the Nitrogen fixer functional group. Some animals have sharp teeth some dull Functional richness Number of functional groups in a community Coefficient of variation Examines how variable a trait is, ex height. CV= standard dev/mean Trait evenness (TE) 1/(standard dev +TS) by van der Plas, where standard dev is TSe space between traits Branches Has meaningful lengths root Common ancestor to all species in phylogeny nodes Common ancestor to descending species Terminal branch Called a tip Estimation of Scientists used morphological traits to group species together. They phylogenies needed to figure out which traits were similar among close relatives. The longer two species evolved independently, greater their phenotypic and ecological diff Phylogenetic diversity Total amount or distribution of phylogenetic branches at the (PD) community level Taxonomic Node counting (many nodes in its ancestry has many relatives, species distinctiveness (TD) with few has few rel), when branch lengths are uncertain Faith’s phylogenetic When branches have lengths which sums the branch lengths diversity (PDfaith) connecting species 19 Equilibrium theory Ecological and evolutionary comprises lead to resource partitioning. Carrying capacity is reached as resources are limiting. Ecologists argue this is unrealistic b/c species’ populations fluctuate in space and time Nonequilibrium theory Fluctuating conditions such as disturbance, stress, predation keep dominant species from controlling resources. This mediates resource availability and affects species interaction and coexistence. When dominant competitor is unable to reach its own carrying capacity, co- existence will be maintained Neutral theory Species don’t differ and diversity patterns are a product of dispersal, speciation and demographic stochasticity Neutral theory order 1. Individual dies at random 2. Area colonized by any other species in community 3. If new species aren’t introduced, all but one will go extinct New species thru immigration and speciation Neutral theory predicts Diversity patterns even when all species are competitively equivalent an use the same resources Landscape ecology Examines spatial patterns and their relationships to ecological processes and changes. Sub-discipline of ecology that emphasizes the causes and consequences of spatial variation Landscape ecologist Looks at spatial arrangement of different landscape elements across earth’s surface and how those patterns affect and are affected by ecological processes Elements of landscape Biotic (plants, animals) abiotic (rain, soil, water, topography) ecology landscape An area in which at least one element is spatially heterogeneous heterogeneous Displaying a varied composition or a mixture of elements. Many differences across space and/time homogeneous Consisting of elements which are similar or identitical. Few to no differences across space/time mosaic Composite of heterogeneous elements Remote sensing Provides images of Earth of large scale ecological patterns GIS Standard for landscape planning, conservation and urban development. Collects, stores, analysis, and displays geologically explicit data thru aerial photographs, satellite image and ground based field studies GAP analysis in USGS Identifies species of concern that aren’t adequately represented on existing conservation lands scale Spatial or temporal dimension of object or process, characterized by grain and extent grain Size of smallest homogenous unit of study (pixel in digital image) determines resolution extent Boundary of the area or time period of study What does grain affect? Quantity of data that must be manipulated. Large grained may be good for regional to continental scales How is extent defined? Can change the composition of landscape being described Landscape composition 4. The kinds of elements or patches and how much of each kind is present. These elements are defined by the source of the data used and investigator. For ex, Yellowstone national park researchers designated five different age classes of lodgepole pine forest using fieldwork, aerial photographs, and GIS. How can the By counting the kinds of elements in the mapped area, y calculating composition of a the proportion of the mapped area covered by each element, or by landscape by measuring the dominance of diff landscape elements such as of a quantified? specie using Shannon index Landscape structure Physical configuration of landscape elements What is landscape Size of patches, whether patches are aggregated or dispersed, structure characterized complexity of patch shape, degree of fragmentation by? What causes landscape Disturbance. In 1988, forest fires burned nearly 1/3 of Yellowstone. A heterogeinty? complex mosaic of patches that burned at different intensities resulted. This dictates landscape composition for decades to centuries Landscape legacies Agriculture, logging, and other disturbances that affect current biodiversity and ecosystem processes even when people have left Examples of landscape In central France, effects of Roman farming settlements were evident legacies after 1600 years: Soil ,PH, phosphorus and plant species richness increased near the Roman ruins which resulted from lime mortar used in Roman buildings and agriculture What does habitat loss Decreases habitat area, isolations populations and alters conditions at and fragmentation do? habitat edges Example of habitat loss In 1986, a massive hydroelectric project in Venezula created islands of and fragmentation tropical forest surrounded by water in what was an intact forest. Small and medium sized islands lacked top predators found on mainland (cats, raptors, snakes). Herbivores, seed eaters and predators of invertebrates were 10-100 times more abundant on islands. The increase in herbivores had a dramatic effect on vegetation as treat recruitment decreased and tree mortality increased. What do human Convert large blocks of landscapes by flooding, clearing, urbanization, activities do? roads etc What are the Reduction of habitat available for other species(results in decline of consequences of human thousands of species), fragmentation(increases edge effects and activities? results in spatial isolation of populations making them vulnerable to the problems of small populations: harder to find mates, pollinators, food, more prone to genetic drift, demographic stochasticity Why do species locally Inadequate food resources, disruption for mutualism, shelter, or go extinct due to nesting sites so animals need to forage beyond their site fragmentation? What was an example Beginning of 1620, vast regions of old growth forest (ancient/virgin of habitat loss and forest) in U.S. were cut down to provide lumber and to make room for fragmentation agriculture, housing An intact eucalyptus forest in Western Aus have been cleared for grazing, further fragmented and only a few remnants of the forest remain (GRADUAL process of habitat loss and fragmentation) What are some animals In the Hudson river valley, forest fragments contain high pop of white- that benefited from footed mice and there are no predators and few competitors. The habitat fragmentation? mice are the reservoirs for lyme disease bacterium and ticks are the vector. Ticks in small fragments(<2 ha) are more prone to carry the bacterium = increased risk of human disease What is the main effect Habitat loss of fragmentation? Edges Total length of habitat boundary that increase as fragmentation increases Edge effects Biotic and abiotic changes associated with the boundary. Physical environment changes over a certain distance into the fragment thus biological interactions and ecological processes change too Amount of edge p/a = perimeter to area. A round habitat has the lowest p/a and measurement irregular shaped patches p/a What is an example of When an intact forest is first fragmented, abiotic conditions change edge effects in the near the edge of the patch of forest that remains, giving rise to biotic Amazon rainforest? changes. After logging, air temperatures increased for 65 m into the remaining patch of forest. The increased air temperature and other abiotic changes lead to tree mortality and the arrival of disturbance adapted plants What were the biotic Higher rates of decomposition, more wind thrown trees and woody conclusions of Chen et debris, and differential tree seedling survival. Pacific fir seedlings al. edge effects in old- survived better in the edges than Douglas fir and western hemlock growth Douglas fir forest? What were the Proximity to a wooden edge increased the probability of nest conclusions of Johnson predation and nest parasitism by cowbirds lowering reproductive and temple’s 5 species success of ground-nesting birds in tallgrass prairies? 18 What are some Heterogeneity, disturbances/ fluctuations and grazing/enemies solutions to the paradox of the plankton? How does species Variation in regional species pool and dispersal or immigration(species richness differ among supply), abiotic conditions, and species interactions communities? What does the regional Provides an upper limit on the number and types of species species pool do? present in a community. Importance of dispersal is seen in non-native species invasions What is a vector for Humans invasive species? What is an example of Zebra mussel destructive invader of inland waterways of US was invasive species in carried there from Europe in ballast water water of USA? How many a specie be By competition, predation, parasitism and disease excluded from a community? Species interaction For species that depend on other species for growth, reproduction, or survival, those species must be present Paradox of the plankton High species diversity despite extreme resource limitation? Conditions in lake changed seasonally, which kept one species from outcompeting the others Resource partitioning Competing species likely to coexist when they use resources in different ways. This reduces competition and increases species richness What does bird species Higher foliage diversity (number of vegetation layers), indication of diversity have in habitat complexity common with? Resource ratio Theory by Tilman suggested species coexist by using resources in diff hypothesis proportions. For example, two tiatom species were grown in media w/ diff SiO2:PO4 concs. Cyclotella dominated when ratio was low, Asterionella dominated when ratio was high What was Robert Control and experimental. Removed starfish (top predator) and Paine’s competitive diversity in experimental plot declined from 15 to 8 (7 lost species). exclusion study on Starfish was a keystone and when it was removed, other species came rocky intertidal zone? and hogged space Immediate disturbance Species diversity should be highest at intermediate levels of hypothesis disturbance by Connell Competitive Growth rate of strongest competitors in community, dependent on displacement productivity of community Dynamic equilibrium Disturbance frequency and rate of competitive displacement combine model to determine species diversity. Levels of disturbance and competitive displacement = same Lottery model Resources are captured at random by recruits from a larger pool of potential colonists. Species have similar interaction strengths and population growth rates, and ability to dis
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