Les things Flashcards

Question

what are biomes

Answer 1

Biomes are the fundamental unit of ecological heirarchy. Based on structure of dominant vegetations. Ex: forest, tundra, grasslands, etc

Answer 2

Terrestrial biomes can be charted based on mean annual temp and annual precipitation. These charts can predict the biome in a region with X temp and Y precipitation. Maps are also used frequently to divide earth into biomes.

Answer 3

Biomes have influence on the ecology of the region, and regulate the regulations and opportunities present in that region. Useful for humans as we can determine where certain things might be able to grow (plantations and crops) theoretically useful to predict change in biomes based on changing climates.

Answer 4

Temperate Rainforests: mild (average temp above 6º C) wet (150-350 cm) Dominated bu a diversity of long lived conifers like sika and spruce. Western hemlock, western redcedar, amabilis fir, yellow cedar, douglas fir. Structually complex, diverse ecosystems. Large disturbances are relatively uncommon.

Answer 5

Temperature deciduous forests Warm summers, average temp around 3º C Moderate precipitation (150-200 cm) dominated by deciduous trees, like oak, maple, chestnut, ash, beaches, etc. Relatively restricted distributions in Canada (mostly Ontario)

Answer 6

Boreal forests (Taiga) cold winters and short warm summers, average temp around -4º C precipitation 50-150 cm has 1/3 of global trees. The boreal forests form a continuous band across the northern hemisphere. Half of canada. Ecosystem structure and composition are strongly influenced by stand replacing disturbances like fire and insects. Dominated by conifers like spruce, pine, larch, and fur.

Answer 7

Tundra Cold, average < -5º C dry, < 125 cm treeless areas dominated by dwarf shrubs, sedges, mosses, and lichens. Underlain by perennially frozen ground (permafrost) Highly variable: from complex shrubs to barren

Answer 8

Montane forests: forested areas below mountain treeline. In northern hemisphere this biome is dominated by conifers, disturbances like fire and insect outbreaks give it a patchy structure like the boreal forest. Can turn into tundra at high elevations.

Answer 9

Temperate grasslands dry, < 60 cm warm > -3 º C soil moisture deficit prevents forest development. Historical extant extended into wetter areas, because fire and herbivores suppressed tree establishment. In Canada it has been severely impacted by land use.

Answer 10

Deserts dry, < 25 cm / year occur across a range of temperature conditions. Soil moisture deficit limits most vegetation depending on definition can occur in Canada in small portions. Technically, none in Canada.

Answer 11

Different parts of the ocean have different productivities. Ocean can be divided into open ocean (which is less productive) and continental shelf (more productive) adjacent to continents.

Answer 12

Ecozones are delineated based on dominant vegetation geology, 15 terrestrial, 2 marine. Ecozones are divided into 194 ecoregions based on climate, vegetation, and soil. Most regions, further divid ecoregions in a larger number homogenous terrain or vegetation units

Answer 13

Biogeoclimatic zones of BC BEC zones are ecologically classified regions by BC ministry of forests. Used to predict climax vegetation based on climate, soil, and geology. 14 zones in BC developed in 60-70s by V.J Krajina (UBC) BEC subzones are additional divisions based on precipitation. Moist maritime vs very wet maritime. Further divided into site association, site series, and site types based on soils, nutrients, and topography.

Answer 14

A problem with the biome classifications is that many ignore human impact, classifying cities as forests, or farm areas as grasslands. Don’t represent contempary state of world. In most cases humans exert stronger control on ecosystems than natural processes. in 2008, Ellis and Ramanutty argued that due to human influence, we should use anthropogenic biomes to account for how we have changed many areas. (Anthromes) = Anthropogenic biomes Ecological classifications are a useful oversimplification, but have many limitations.

Answer 15

Electromagnetic (photons) EM spectrum: gamma → radio waves Kinetic energy (motion): thermal, mechanical, etc Potential energy (stored): chemical, electrical, elastic, etc Joules are the standard unit

Answer 16

Energy flow to different areas in an ecosystem follows thermodynamic laws. 1st law of thermodynamics: law of conservation, energy cannot be created nor destroyed, only changed 2nd law of thermodynamics: Spontaneous energy transformation increases entrophy in a system. No real process can be 100% efficient.

Answer 17

Entropy = measure of disorder in a system, the amount of energy that is not available for work during certain processes.

Answer 18

All life requires energy, where does the energy come from. Solar radiation, in the form of electromagnetic radiation. Energetically, the earth is an open system. Sunlight is reflected or absorbed by the earth.

Answer 19

1. In = Out, all incoming energy exits at some point 2. The greenhouse effect helps hold the energy on earth for a time, keeping the earth ~33º C higher than it would be (increasing GH gases, increase this). H2O, CO2, CH4, absorb some dissipated IR radiation and reradiate it keeping the temp higher. 3. Photosynthesis is a small budget item. < 1% of incoming energy is captured

Answer 20

Autotrophs capture inorganic energy and fix it into organic energy. They are the base of the energy web Photosynthetic autotrophs: those that use the sun for energy. Most important. Chemoautotrophs: take energy from chemical sources

Answer 21

6CO2 + 6H2O + light → C6H22O11 + 6O2 Converts solar energy into chemical energy, fundamental mechanism by which energy enters the ecosystems

Answer 22

Rubsico, a key enzyme involved in photosyntesis is likely the most abundant protein on the planet

Answer 23

Some like Monotropa uniflora have no chlorophyll and get energy parasitically from other plants via mycorrhizal fungi Others like Drosera rotunifolia are photosynthetic but get additional energy by capturing insects.

Answer 24

GPP = Gross Primary Productivity It is the rate at which energy (or biomass) is generated by primary producers. Measured in Joules/m^2/day Energy is contained in chemical compounds within biomass

Answer 25

Plants also burn sugar through respiration to get usable energy C6H22O11 + 6O2 → 6CO2 + 6H2O + energy ATP = energy currency Aerobic respiration uses O2 and produces CO2. Anaerobic respiration doesn’t use O2 and produces CH4, HO2, or other compounds.

Answer 26

NPP = GPP - respiration Plants use 25-75% of energy fixed for growth At global scale NPP roughly equals 1/2 GPP NPP is energy available to consumers

Answer 27

Humans use around 20-25% of global NPP

Answer 28

- available radiation - growing season - temperature - Available moisture - nutrients

Answer 29

One of the reasons plants need tons of water, is that for them to take in CO2, they open their stomata, which let CO2 in, but also let H2O out, increasing water loss

Answer 30

At a global scale nutrients and soil development are controlled by climate, parent material, and topography Climate change makes some areas more productive, others less. Effects are mixed. Tundra productivity is increasing due to warmth. Places like boreal forests seem to get less productive.

Answer 31

In the ocean NPP is controleed by nutrient availability, upwelling. Limited by lack of light wth depth. 97.5% of ocean is below photosynthetic zone. In tropics, warm waters prevent upwelling/mixing with nutrient rich deeper levels.

Answer 32

- the most productive biomes are less constrained by resource availability (sun, water, nutrients) - Reefs and estuaries have productivities comparable to productive terrestrial ecosystems (8-9 Tons of Carbon per hectare per year) 6% of global productivity - Open oceans are less productive (0.57 T C /ha*yr) on a per area basis, because they are limited by low nutrient levels - However because open oceans occupy a huge area it accounts for 30% of global NPP

Answer 33

Continental: 48.3 * 10^9 T C/yr 66% Marine: 24.9 * 10^9 T C/yr 34% Total: 73.2 * 10^9 T C/yr

Answer 34

Trillions of phytoplankton live on the surface of the ocean, taking in CO2 and releasing O2. They are studied from space, showing how earth is changing over the years. Higher ocean temps correlate to lower levels of phytoplankton due to less nutrient cycling from lower water.

Answer 35

Energy moves from food to consumer. But food webs can be very complex. Food webs show interactions between predator, prey, plants, animals, etc within an ecosystem.

Answer 36

Autotrophs - make energy from inorganic materials Heterotrophs - eat Autotrophs (primary consumers) or other heterotrophs (secondary+ consumers) Detritivores - eat dead material

Answer 37

In many ecosystems the amount of energy and biomass produced declines as you move up trophic levels (producers → consumers) Partially due to thermodynamics, inefficiency, and messiness of animals Secondary Productivity: the rate of biomass production by heterotrophs Only a small percent (~10%) of energy moves to next trophic level Trophic efficiency Pn/Pn-1 = 0.1 = 10%

Answer 38

Only a portion of NPP is consumed 1. Consumption efficiency Not all consumed energy is used 1. Assimilation efficiency Not all energy used is converted into new biomass 1. Production Efficiency

Answer 39

NEP (Net Ecosystem Productivity) The net accumulation of carbon by an ecosystem NEP = GPP - (leaching + disturbance + respiration) Some ecosystems store more carbon than others. Ex: High biomass in old growth forests compared to low biomass in disturbed or young ecosystems

Answer 40

Currently about 1/2 of earth’s soil carbon is stored in the soil of tundras and boreal forests. 2x that in the atmosphere. Global carbon sinks have importance for global warming Ecosystems that accumulate biomass and store it are often called carbon sinks Peat lands are ecosystems where peat (partly decomposed organic matter) accumulated at the surface. Waterlogged (Anaerobic) conditions and sometimes cold temperature, limit decomposition more than NPP Land use also impacts the climate system. 23% of GHG emissions

Answer 41

Total Continental NEP = 55.5 TC/ha Total Marine NEP = 0.05 TC/ha in marine ecosystems there are higher turnovers, most material is consumed The ocean still acts as a carbon sink, but this is inorganic carbon brought into solution and stored deep in the ocean, not from autotrophs

Answer 42

rivers carry nutrients to their deltas creating rich ecosystems. But this can be a problem when algal blooms are so intense they change the ecology of the region. Creating a dead zone which persists for a variable amount of time. ~1.6 million tons of fertilizer runoff enters the mississipi river, leading to algal blooms.

Answer 43

Movement of energy and matter in ecosystems = Energy Flow The planetary energy budget: in = out. In moderate timescales all energy that comes in, exits (with a minor exception in NEP) For nutrients earth is a closed system as no new nutrients enter earth.

Answer 44

Macronutrients: required in high concentrations Carbon (46-50%), Oxygen (45%), Hydrogen (6%), Nitrogen (1.5%), Potassium (1%), Calcium (0.5%), Magnesium (0.2%), phosphorus (0.2%) and sulphur (0.1%)

Answer 45

Micronutrients: required in low concentrations <100 ppm Chloride, Iron, Manganese, Boron, Zinc, Sodium, Copper, Nickle, Molybdenium

Answer 46

Elements like nickle and copper can be toxic in high concentrations Long exposure can lead to evolution of tolerant populations and species Halophytes are plants which can tolerate high levels of salinity. Some plants can hyperaccumulate metals and are important in environmental remediation

Answer 47

1. Soils = diverse communities of bachial fungi, plants, and animals critical to nutrient cycling 2. Soil formation involves biotic and abiotic processes and occur over long millennial time scales 3. Critical soil forming factors include: 1. parent material 2. climate 3. topography 4. organisms 5. time

Answer 48

Pool = where materials are found in ecosystems (qualitative or quantitative)

Answer 49

Flux = quantitative value representing transfer of materials between pools

Answer 50

Sources = exporters of material to other parts of the ecosystem

Answer 51

Sinks = parts of the system that have a net input of material, receive more than they output

Answer 52

Pools: - atmosphere - ocean - oil, coal and natural gas - minerals and rocks - living matter - peatland - permafrost - soil

Answer 53

Fluxes: - respiration - decomposition - combustion - photosynthesis - thawing of permafrost - consumption - Erosion

Answer 54

Since 1960 atmospheric carbon has gone from 320 ppm to 428.5 ppm

Answer 55

Nitrogen is the most abundant gas, but it is also a limiting nutrient in growth as its hard to access in its N2 form So organisms do nitrogen fixation which turn N2 into usable forms like ammonia

Answer 56

4 Processes to Remember: - Nitrogen Fixation (N2 → organic nitrogen) - Ammonification (organic nitrogen to ammonium) - Nitrification (ammonium to nitrate) - Denitrification (nitrogen to nitrogen oxide)

Answer 57

- most organisms access nitrogen as NO3 or NH4 (some can also use N2) - some plants and lichens form symbiotic relations with bacteria which can fix N2 - free living bacteria can fix N2

Answer 58

Ammonification produces ammonium Nitrificaiton forms nitrate from ammonium Denitrification reverses ecological effect of N-fixation Anaerobic process that produces nitrogen gas Processes described above are driven by bacteria and fungi

Answer 59

Phosphorus can be a limiting nutrient in ecosystems, especially in aquatic environments Lacks atmospheric phase, enters from weathering of rocks Ecosystems drive the one way movement of phosphorus from earth materials to ocean sediments

Answer 60

A few animals go against this flow by transporting it from ocean to land Salmon impart phosphorus to riparrian environments when they spawn Piscivorous birds can also import phosphorus from aquatic to terrestrial environments

Answer 61

Sulphur is needed for amino acids, proteins, enzymes, vitamins, hormones, etc Abundant in rocks and ocean sediments Weathering of rocks drives a large input of sulphur to ecosystems Atmospheric sulphur from volcanoes and human combustion also constitutes a large input.

Answer 62

Smelting various ores like nickle releases sulphur into the atmosphere leading to the formation of sulphur oxide, and sulphuric acid. Leading ot acid rain which lowered the pH of lakes, soils, and other things, in the 20th century. Recently the pH in many lakes have been recovering from those times.

Answer 63

Atmospheric CO2 has increase by 36% and methane has doubled. Increases in atmospheric CO2 are caused by fossil fuel use and global patterns of land use change The increased concentration of greenhouse gases is changing the radiative properties of the planet and altering the global climate.

Answer 64

Industrial nitrogen fixation via the Haber-Bosch process changed the world by decoupling food production from manure and composet. We now fix as much nitrogen as natural sources. In 100 years we have double the terrestrial N pool

Answer 65

Acid Rain. SO2 produced from fossil fuel combustion and smelting of sulphide-ric ores reacts in the atmosphere to sulfuric acid

Answer 66

Cultural Eutrophication. Nutrient enrichment (N,P) increases productivity, decreases oxygen, and reduces diversity (fish and invertebrates)

Answer 67

Ecologists use statistics to understand variation and deal with uncertainty. With any statistics there is a degree of uncertainty associated with a value. Due to measurements, variability, error, etc. A 95% confidence interval is used to show where the true value should fall with 95% confidence.

Answer 68

Mean: average observation Median: Central observation Mode: most frequent observation These describe the central tendency of a population of data

Answer 69

$x_n=(∑x_i)/n$ $x_n=(x_1+x_2+x_3...+x_n)/n$

Answer 70

Differences in the true value and the measure value. Measurement error is caused by random error and systematic errors in measurement

Answer 71

Error that arises when statistical characteristics of a population are estimated from a sample

Answer 72

In ecology the groups of things we are interested in tend to be large. Instead of measuring everything we focus on a sample of the entire population. We use the sample to infer characteristics about the population. A small sample size raises the impact of individual variation.

Answer 73

Random: Are your data selected at random from the population you are studying? Has every data point available got the same chance of being selected? Independent: Are subsequent observations independent from each other?

Answer 74

Ecological systems are highly variable We estimate population characteristics by sampling. Variability effects our estimates parameters like the mean Ecologists seek to distinguish natural variability from differences caused by processes of interest (Climate, pollution, predation, succession).

Answer 75

Theoretical probability distribution, Fundamental in statistical inference. Symmetrical around the mean (mean = median = mode) Most observations are clustered around the mean. A few observation are much smaller or much larger than the mean. Bell curve.

Answer 76

If something is normally distributed, 68% of all values are within 1 standard deviation of the mean. 95% of all values are within 2 standard deviations of the mean. >99% of all values are within 3 standard deviations of the mean.

Answer 77

The range of values various significantly. The size of one standard deviation changes based on a population of data. Different normal distributions have different means and variences. Some things are highly variable, others are uniform.

Answer 78

Sample variance $s^2=(∑(x_i-x_m)^2)/(n-1)$ $x_m = mean$ $x_i$ = individual observation n = number of samples Sample variance is the average of the squared deviations from the mean.

Answer 79

Standard Deviation $S=√S^2=√((∑(x_i-x_m)^2)/(n-1))$ Standard deviation is the square root of the variance. 68% of observations should fall within 1 standard deviation of the mean. 95% should fall within 2 standard deviations of the mean.

Answer 80

Biodiversity = sum total of variation of life on earth Biodiversity = Biological diversity “the total diversity and variability of living things and the systems which they are a part” Heywood 1995

Answer 81

Genetic Diversity: Genetic variation in species, including within and among population variability

Answer 82

Species Diversity: the number of distinct species (in a given place at a given time)

Answer 83

Ecosystem Diversity: Diversity of communities and their environmental interactions

Answer 84

“The variability among living organisms from all sources, including, inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species and of ecosystems.” - Convention on Biological Diversity 1992

Answer 85

Individuals in different populations and individuals within the same population differ genetically. Individual with different alleles (variant for a gene) Populations with different allele frequencies (proportion of the population with a given allele).

Answer 86

Diversity provides opportunities to adapt to changin environments and increases productive fitness. Different alleles can result in altered resource use efficiency, morphology salt tolerance, disease resistance. Small populations with low genetic diversity have low fitness Genetic diversity varies at three fundamental levels: 1) individual, 2) within population, and 3) among populations

Answer 87

Agrobiodiversity (diversity in agricultural systems) Genetic diversity in crop varieties and their wild relatives Vital to sustained food production because it offers solutions to problems encountered in agriculture (disease, pests, salinity, drought stress, nutrient limitation, etc)

Answer 88

Agrobiodiversity is maintained by local/indigenous knowledge-practice- belief complexes. Extension of the concept of biodiversity to include linguistic and cultural dimensions

Answer 89

Biocultural diversity is the diversity of life in all its manifestations, biological, cultural, and linguistic, which are interrelated within a complex socio-ecological adaptive system.

Answer 90

Alpha diversity is the number of species in a given area (usually small homogenous) Gamma diversity is species richness over a larger area (region-continent) Beta diversity is the difference in species diversity among habitats or communities. Higher means there are larger differences in the species present between / among regions

Answer 91

A few ways to calculate (Sensu whittaker): Bw = y / a mean Regional richness (gamma) divided by average local richness (Turnover) Bt = (a1-overlap1+2) + (a2 - overlap 1+2) The number of unique species at tow (or more) locations, referred to as species turnover between habitats

Answer 92

How variable is community composition and ecological unit in region / continent? How many distinct ecological communities are there in a given area? Ecozone? Biogeoclimatic Zone? Biome? Scale is a key consideration here (biomes vs BEC subzones)

Answer 93

There have been five mass extinctions in geological history 1. Ordovician - half of all animal families lost, (trilobites were particularly hard hit). 2. Devonian - 30% of all animal families 3. Permian - over half of all families of marine invertebrates and vertebrates went extinct (largest mass extinction event) 4. Triassic - 35% of existing families 5. Cretaceous - end of the dinosaurs

Answer 94

We are witnessing the sixth major extinction event Estimates of the potential magnitude of the crisis range from 1-10% loss per decade (Gibbs 2001). Causes: Habitat destruction/alteration, Introduced species, overexploitation, climate change, nitrogen deposition

Answer 95

The convention on Biological Diversity As of 2002, 193 Nations had committed to reducing rates of biodiversity loss through the CBD. Reducing biodiversity loss is also a component of the Millennium development goals.

Answer 96

About 2 million species have been described. There is a huge bias in the data we have. Some groups and places have been better studies than others (mammals, birds, temperate regions) The plant hosts between 30-50 million species (according to Freedman et al 2014). Other estimates give a larger range (5-150 million). About 60-99% of species diversity is unknown. Methodes for estimating the total number of species involve examinations of genetic variation and the use of species area relationships.

Answer 97

Biological species concept “groups of actually or potentially interbreeding populations, which are reproductively isolated from other such groups” (Mayr 1942)

Answer 98

Morphological Species Concept “A group of individuals that is morphologically, physiologically, or biochemically distinct from other groups” (Primack 1998) Problems: Sibling species (species that are indistinguishable based on morphology and physiology, but are biologically distinct and do not interbreed).

Answer 99

To enumerate species diversity wee need more taxonomists / systematists 20000 new species are described / year. Describing 5-150 million species would take 175-7500 years.

Answer 100

There are more species in the Tropics. Birds, plants, and other species increase in diversity towards the Equator.

Answer 101

Ambient Energy Hypothesis: Diversity is controlled by available energy

Answer 102

Stability Hypothesis: Tropical areas have been free of major disturbance for longer, and uninterrupted, have accumulated more species

Answer 103

Evolutionary speed hypothesis: Warmer temperatures and shorter generation times may cause more rapid speciation in the tropics.

Answer 104

Competition Intensity: more intense species interactions (predation, competition, etc) in the tropics increases specialization and thus diversity.

Answer 105

Population Ecology: The study of populations and their interactions with their environment Focus on the factors that influence population dynamics (changes in #, movement, etc).

Answer 106

Population 1: Group of individuals of the same species with no, or very limited genetic exchange, with other populations. Population 2: All the individuals of a given species in a given place at a given time.

Answer 107

Nt = N0e^rt Populations with a constant growth rate expand exponentially. They double after t = ln(2)/r

Answer 108

r = the instantaneous rate of increase The units of r are individuals / individual * time let’s assume that r = 0.25 (so 1 in every 4 individuals has offspring in a given year)

Answer 109

System is closed - no immigration or emigration No population structure (differences in size and age) Spatial area remains constant Resources infinite

Answer 110

Can happen in some cases, early stages of succession, or bacteria in a petri dish before the exhaust the space and resources. But generally, does not accurately predict population.

Answer 111

Since populations with low r take longer to increase, they can be more vulnerable to disruption of population or extinction events. Dictates recovery time. Higher r helps respond to pressure better. Population recovery in endangered species Productivity in commercially harvested species r is also used as a measure of fitness and is linked to reproduction

Answer 112

Population growth when the environment it limiting In logistic growth we assume that the change in population size depends on population size, relative to the carrying capacity.

Answer 113

K = carrying capacity, the maximum population that can be supported by an environment.

Answer 114

In logistic growth: dN/dt = rN*(K-N/K). The higher the N value, the slower it is compared to exponential growth. When N = K, growth stops Nt=K/(1+[K-No/No]e^-rt

Answer 115

changes in population size are a function of distance form carrying capacity (K) growth slows as a population approaches K

Answer 116

there’s no population structure Closed system, no immigration or emigration Spatial area remains constant

Answer 117

Autecology is the study of the relationships of individual species with their environment

Answer 118

Differences in growth and reproduction among species are referred to as life history strategies. Key Life history traits: 1. Age at maturity 2. Lifespan 3. Fecundity (the potential number of offspring that can be produced) 4. Size and number of offspring 5. Amount of parental care

Answer 119

Life history traits are significant because they impact population growth rate and fitness (reproductive success) Population growth rate increases as the age at maturity decreases. Population growth rate decreases as organisms size increases. Fitness (the contribution that an individual makes to future generations) depends on reproduction and survival.

Answer 120

Ecologists studying life histories have focussed on understanding trade offs. Trade offs. The idea that organisms cannot invest in all traits at the same time. It is not possible to maximize: Offspring size and offspring number, Growth and reproduction

Answer 121

There are two influential life history classifications that we will cover 1. rK model (Macarthur and Wilson 1967) 2. Triangular model (Grimes 1969)

Answer 122

K strategists (Efficient resource use) Slow growth few offspring later reproduction large body size repeat reproduction poor colonizers k strategist are successful in stable habitats where competition is high and survival is Key

Answer 123

r strategists (Rapid Reproduction) rapid growth many offspring Early reproduction small body size single reproduction Good colonizers but poor competitors r strategists are successful in variable habitats, where population is not close to capacity and competition for resources is typically low. Where rapid reproduction is Key

Answer 124

Grime developed a conceptual model that included three factors influencing life-history adaptation in plants. 1. Competition 2. Disturbance 3. Stress (low resource availability) Putting these together effectively characterizes the environment faced by plants

Answer 125

Grime’s Triangle maps three main life history strategies in plants. 1. Ruderals (small/rapid + prolific seed production) High disturbance, low stress 2. Competitors (efficient resource acquisition and growth) High competition and low distrubance 3. Stress-tolerators (allocate resources to maintenance and survival)

Answer 126

In stable environment ecological processes are controlled by the environmental factor that is present in the lowest quantity relative to demand for it. There are some examples where this is clearly evident. examples include: Phosphorus in oligotrophic lakes and nitrogen in Arctic tundra. In many systems this idea is not that useful, because environmental conditions vary in very complex ways in space and time.

Answer 127

Shelford’s law states that the success of species and populations is controlled by a suite of environmental factors. Each of these factors has a maximum and minimum value, and an optimal range. Include: Abiotic factors like temperature, salinity, soil nitrogen. And Biotic factors like predation, competition, and herbivory.

Answer 128

Within the optimum range growth, reproduction and abundance are highest. A given species or population has theoretical tolerances, above and below which it cannot survive. Outside the optimum range environmental factors slow or prevents growth/reproduction.

Answer 129

Within the optimum range growth, reproduction and abundance are highest. A given species or population has theoretical tolerances, above and below which it cannot survive. Outside the optimum range environmental factors slow or prevents growth/reproduction.

Answer 130

The sum total of these tolerances for different environmental factors defines the ecological amplitude (valence) for a particular species. Generally, species with a large amplitude are more abundant and have large ranges. Alternatively: rare species have restricted ranges. This general pattern is referred to as the distribution - abundance relationship

Answer 131

the niche is another way to define the limits of where a species can exist. Based on conditions and resources required for survival. Moisture, Nutrients, substrate. Hutchinson described the niche as an n-dimensional hyper volume. Individual dimensions are defined by the upper and lower limits for a given parameter. **Resources**: food, nesting sites, space, light, CO2, and **Conditions**: temperature, relative humidity, pH, etc. Each condition / resource adds a dimension to a species.

Answer 132

Climate envelope models (CEM) infer a species environmental requirement by correlating their occurrence with environmental data. ex charting present of a tree species based on temperature and precipitation. The ‘envelope’ defined by these statistical associations can be used to make predictions about how species will respond to future (or past) environment.

Answer 133

- Model input defines output, so models are limited by lack of information. - Projections of future climates won’t be completely accurate/precise. - We don’t know how organisms will adapt - Limited to a number of variables, hard to account for many variables. - Other factor’s include: Competition, herbivory, seed predation, disease, soils, nutrients, disturbance - Shift in species distrubution requires dispersal, establishment and survival. - Just because a species can live in an environment doesn’t mean they will.

Answer 134

Communities are groups of species in the same place at the same time. They have complicated interactions within them between different species of plants, animals, fungi, etc.

Answer 135

Focus in community ecology is on how interactions between species, population and the environment affect the structure of communities in space and time. Can we predict what a community will look like over time with varying conditions. Community ecologists have also spent considerable effort searching for theory to explain community structure. Why are some species rare? Why do communities assemble in the way they do?

Answer 136

A biological community consists of all the species that occupy a given place and the interactions among those species. Includes all organisms (bacteria, viruses, fungi, plants, animals, protists, etc)

Answer 137

Research on communities is often taxonomically focused on a subset of a given community (certain groups of organisms - plants, birds, etc) Some community ecologists focus on **guilds** (species that use the same resources, ex seed eaters) Others focus on **functional groups** (species that perform similar functions, like shredding invertebrates or nitrogen fixers) Other focus on **trophic levels**

Answer 138

An **association** is a well defined community that must occur in more than one place, have consistent floristic composition, uniform vertical structure and physical appearance and occur in a specific habitat. Defining boundaries is not always straightforward. There are opposing vies on whether associations are real entities.

Answer 139

The organismic view Communities are discrete and distinct entities (associations) Clements asserted that species in associations have evolved and adapted together and have integrated function and tight linkages. Clements likened the consistent development of plant communities to that of an organism.

Answer 140

The individualistic View - Gleason, Henry Allen Changes in species composition occur gradually across environmental gradients and communities are not grouped into defined associations. Gleason argued that individual species have their own environmental tolerances and that plant communities are the product of chance historical events and interactions between individual species and the environment.

Answer 141

Where environmental change is abrupt the line between communities is distinctive and association are clear. Where environmental change is gradual the individualistic response of species make these lines and association fuzzy. Boundaries between communities and the factors controlling them are scale dependent.

Answer 142

Diversity Indices Alpha diversity = number of species in a given area This doesn’t tell you the evenness (is one species more abundant, are some rare, etc) and abundance of species in the community (one ecosystem might have way more organisms than another but the same number of species). Relative Abundance = Dominance/Rarity

Answer 143

The abundance of individual species in a community are each variables that describe a single dimension of community composition. Species abundance can be measured in many ways (%cover, # of individuals, biomass, etc,) Most Communities have 10-1000s of species that define their compositions. n - dimensional hyper-volume that defines the community.

Answer 144

In the logistic and exponential growth models all individuals are treated reproductively equivalent. They assume populations have no structure for some rapidly maturing (r-selected) species this is realistic, but for many slow to mature species this is too simplistic Individuals of different ages are more or less likely to survive and Individuals of different ages differ in their reproductive output.

Answer 145

Graph number of survivors (on a log scale) vs age in relative units Generally three types Type 1: Low mortality at young age, most survive into old age. Ex People now a days (k strategist), big mammals Type 2: More or less linear, equal chance to die throughout lifespan. Mortality is evenly distributed over age classes. Rare but some bird species have it Type 3: Most individuals die at a young age, very few make it to old age. Ex Trees (r strategist) Real populations don’t follow perfectly, but some approximate them.

Answer 146

Reproductive value = Present progeny + future expected progeny Reproductive values are dependent on timing of reproductive maturity and probability of survival

Answer 147

Matrix models use estimates of vital rates at different ages (or stages) to project future population change Extension of life tables (used by insurance companies) which estimate the probability of further life based on age Incorporate age (or stage) specific estimates of fertility and survival probability. Also male vs female. These models can be used to project population size into the future and estimate stable growth rate.

Answer 148

Look like this: Stage 1 - yearlings Stage 2 - Juveniles Stage 3 - Reproductive adults Stage 4 - Post reproductive adults G(1-3) - probability of moving into next stage P(2-4) - probability of surviving and staying in stage F(2-4) - stage specific reproduction

Answer 149

Population Viability Analysis: PVA Use of population models to estimate the probability of extinction for populations of different sizes. Typically include factors such as demographic stochasticity, environmental stochasticity, natural catastrophes. Projections can also be run using simulated conditions including harvesting intensity, initial population size. It can be used to determine how much of a population can be harvested without leading to decline. Along with how many individuals are needed to keep the extinction risk below 5% over 100 years.

Answer 150

- Habitat fragmentation - Closed populations

Answer 151

Most Populations are not closed, but are lined into metapopulations through immigration and emigration. Metapopulation: network of semi-isolated populations with some level of regular exchange (Immigration (I) and Emigration (E)) and gene flow. Connectivity varies among species and contexts.

Answer 152

Metapopulations models focus on extinction, persistance, and colonization of local populations. The simplest model (The Levin Metapopulation Model) predicts the proportion of local populations occupied. Not the number of individuals. More complex models also track the number of individuals.

Answer 153

- Metapopulations models teach us that the number of patches (occupied or empty) influence species/population persistance - The importance of empty patches highlights the importance of regional and landscape conservation - some patches are better than others - Source: patches where habitat is good (growing population that are net exporters of individuals) - Sink: patches where habitat is generally poor (declining population that depend on immigration from sources)

Answer 154

Over the last 150 years the Earth’s temperature has risen by 1º C It is likely to rise between 2-5 degrees by the end of the century As the global temperature increases, organisms move toward the cooler poles. On average, land-based species are shifting poleward at a rate of 17 km a decade. But some species are moving faster, slower, or in the other direction, resulting in a cascade of consequences.

Answer 155

Bombus affinis, the rusty-patched bumble bee, was once common across eastern North America. Its population has plummeted to where nobody in Canada has seen one since 2009. It is the only endangered bumblebee species in the U.S or Canada, but not the only one under pressure.

Answer 156

Bumblebees and other species are on the move. For land-based species this is at a rate of between 6-17 Km a decade on average based on different estimates. For marine species this is four times as fast. However, ecosystems aren’t moving at the same rate, two trees might respond totally differently, and two animals that would never meet might be trust into contact.

Answer 157

The honeybee, Apis mellifera is a single domesticated species imported to NA 400 years ago. (Indigenous people called them the white man’s fly.) Like any livestock they are continuously managed by humans.

Answer 158

Evidence is mounting that a class of widely used pesticides neonicotinoids is damaging honeybee colonies. And having an impact on bumblebee colonies too. European honeybees are dis-similar to the 42 species of wild bumblebees in Canada, and not all species will behave the same way under the same stressors. A lot of the declining species have ranges in the boreal forests, or protected areas like the Smoky mountains. Living the question of why wild bees are in decline.

Answer 159

in 2015 a team of researches tried to answer the question by analyzing 67 different species of bumblebees. They gathered more than 400,000 instances when a specific bumblebee was observed in a specific location. Then they compared records of observations gathered between 1901 and 1974 to records collected in recent years. Nearly all the species had seen losses along the southern edges of their ranges. On average more than 230 km of range were lost. But the northern edges had failed to shift poleward, and in some cases moved south.

Answer 160

Why they failed to shift poleward in unclear, it may have something to do with their life-cycles. Butterfiles can eat, move and eat again somewhere else. But bumblebees are “central place foragers”: a colony is tied to its nest. Queen bees build their nests in early spring and for the rest of the summer, worker bees and then new queens and males return to this nest for food. The only opportunities to relocate are when the queen emerges from overwintering in rotten logs or mulch to build the nest, and at the end of the season, when new queens mate and find a sport to overwinter. These two opportunities to disperse are brief, and in both cases, energy is scarce. Queens are starving when they first emerge in spring, and in fall, besides being busy trying to find a mate, the plants they prefer to forage on may be less available.

Answer 161

Some plants like tomatoes, peppers, eggplants, blueberries and roses, require “buzz pollination”, where bumblebees vibrate their thoracic muscles to shake pollen in the flowers loose. vibration also keeps bumblebees warm allowing native bees to be more effective in Canada’s climate.

Answer 162

The boreal is the largest intact forest system on the planet, a thick ring that circles the northern hemisphere below the Arctic circle. Roughly a third of earth is boreal, and 28% of it is in Canada. It has cultural, economical, and ecological importance.

Answer 163

For boreal-obligate species this is especially important. Recently a group led by Murray and Michael peers from UofA examined 12 species including black spruce, grey jay, caribou, and moose. The team looked at the current environmental suitability of the niches of each species, inputting climatic conditions like the hottest, coldest, wettest, and driest months. Then they modelled how those conditions would shift in the coming decades.

Answer 164

A minority of species, like northern flying squirrel and the jack pine, broadly benefited from the warmer, drier conditions. But most of the 12 species saw their ranges severely contract and shift northward. The boreal chickadee and spruce grouse lost more than 30%, Moose lost 37%, and Caribou lost over 50%. Based on these models some species like moose and caribou could have completely isolated east and west populations. Such constriction is usually bad for animals and their resilience, especially during times of rapid environmental change.

Answer 165

Caribou happen to be particularly sensitive to the pressures on their habitat. Once more than a third of their terriory is compromised, caribou populations begin to suffer. White-tailed deer move in, carrying a brain parasite that deer tolerate but kills caribou. Moose move in too, and predators like wolves follow the deer and moose.

Answer 166

Various satellite and ground level photographs from the 20th century show that low-lying deciduous plants like dwarf birch, willow, and alder, had dramatically increased. The decline in lichen might also have an impact on barren-ground caribou. Which have dropped from 2 million in the 1990s to 800,000 today.

Answer 167

Canada, as party to the international Convention on Biological Diversity, has committed to protecting 17 percent of its terrestrial area and 10 per cent of its marine territory by 2020. We have a long way to go: in 2016, Ottawa reported that it had set aside 10.6 percent terrestrially and 0.96 percent of oceans.

Answer 168

by 2100 2 billion humans will have been displaced by sea level rise. Climate change also allows disease carrying insects, mites, and ticks to spread further north into Canada. Lime disease has already started occuring in Canada.

Answer 169

Symbiosis (living together). Close long-term relationship between two organisms.

Answer 170

A simple classification of symbioses includes. 1. Mutualism (+/+) 2. Parasitism (+/-) 3. Commensalism (+/neutral) Like most things in ecology there is a spectrum here. Symbiotic relationships can be: 1. Obligate. Required fro survival 2. Facultative. Not required for survival

Answer 171

interactions between species were both benefit. Ex: Swollen thorn Acacia provides food and shelter for Acacia ants in exchange for protection.

Answer 172

Mycorrhizae. A symbiotic association between fungi and plant roots that increases access to nutrient and water. The most important symbiotic association on the planet. (often mutualistic, not always). Some estimates suggest that 20% of carbohydrates from photosynthesis are delivered to mycorrhizae.

Answer 173

Plants get more nutrients and water. Fungi get carbohydrates from photosynthesis. In tundra ecosystems mycorrhizae help tundra plants short circuit the nitrogen cycle, allowing them to utilize amino acids.

Answer 174

Fungal endophytes are another group of fungal symbionts within leaves, stems, etc. Reduce herbivory, increase disease resistance, growth, etc.

Answer 175

Common Mycorrhizal networks (CMN) can connect plants of the same or different species. May influence nutrient sharing. The importance and ubiquity of CMNs is not clear.

Answer 176

Introduction of N-fixing tree *Myrica faya* to hawaii. Faya tree forms dense, monotypic stands on ash and soils. Causes a 5-fold increase in N inputs. Dominance prevents native plant recruitment while facilitates establishment of other invasive species. Green alder is making its way into the tundra, likely due to its ability to fix nitrogen due to a symbiotic relationship. Pushing out shrubs and other vegetation.

Answer 177

Species interactions in which one species (the parasite) benefits, while the other species (the host) is negatively impacted.

Answer 178

Mountain pine beetle (*Dendroctonus ponderosae*) is a species native to N. America that feeds on, and nests in, the cambium of pine trees. Also introduces a blue staining fungus. Since 1990 high populations of MPB have killed ~50% of the marketable pine in BC. Population growth is limited by cold winters and climate change has exacerbated the spread. MPB is spreading east and north, where it now infects hack pine. Possibly stalled now

Answer 179

Parasites can have a transformative effect on community composition, structure and function. Chestnut blight is a fungal pathogen introduced to North America in 1904 that infects cambial tissue in American chestnut. In approximately 50 years the spread of this pathogen completely eliminated chestnut from north American forests (~36,000 square kilometres)

Answer 180

Interactions between two species where unequal use of the same resources (nutrients, sunlight, nesting sites, mates, forage prey, etc) leads to adverse effects for one of the species Species must exert more energy for resources in the face of competitors.

Answer 181

1. Intraspecific competition (between two members of the same species) 2. Interspecific competition (between two members of different species)

Answer 182

The frequency of lake drainage is increasing in the old crow flats due to climate change influencing permafrost. In the first 8ish years after drainage the vegetation is mainly low lying R type vegetation. After 10-15 years the low lying vegetation has been overgrow by taller willows. Later on the competition causes the space to open up as not all willows can survive.

Answer 183

1. Resource competition. Competition for resources in short supply. Direct interaction is not required 2. Interference competition. Species harm each other in the process of accessing resources (physically interference, chemically altering soils.)

Answer 184

The release of growth or germination inhibiting compounds by competing species. Form of interference competition common in plants. Ex: Black walnut (Juglans nigra) Produces a molecules called Juglone in its leaves, roots, husks and fruit which inhibit respiration in sensitive plants. *Acer circinatum, Arbutus menziesii,* and *Rhododendron albiflorum* are likely Allelopathis in the Pacific Northwest. Sometimes plants that grow after forest cuttings can alter the soil beneath them and prevent the regrowth of trees in that area.

Answer 185

Hutchinson described a niche as an n-dimensional hypervolume. Individual dimensions are defined by a given upper and lower limits for a given parameter. Resource: food, nesting sites, space, light, Co2 Conditions: Temperature, relative humidity, pH etc. Each condition or resource adds a dimension to the space where a species can make a living

Answer 186

Fundamental niche: ecological space is occupied by a species in the absence of competition and other biotic interactions

Answer 187

Competition and other interactions can exclude a species from part of its fundamental niche. The actual area that a species occupies is called its realized niche. Realized Niche: that portion of the fundamental niche occupied by a species when competitors and predators are present.

Answer 188

Niche Overlap: Measure of how much specie overlap in terms of resource use. ex: Two species of cattail (T latifolia and T. angustifolia) co-oocur along pond edges Experiments show that when grown alone both species can tolerate a wind range of conditions Grown together T. latifolia is found in shallower waters and T. angustifolia is found in deeper waters. In this case competition is referred to as asymmetric. T latifolia excludes T angustifolia from shallower water, but T angustifolia does not exclude T latifolia from water. Competitive release occurs when fundamental niches overlap and one species is removed.

Answer 189

In many experimental systems when species are grown together one is excluded. **Gause’s Principle (1932)**: Complete competitors cannot coexist. Why are ecological communities diverse?

Answer 190

If two competing species co-exist in a stable environment they do so as a result of niche differentiation Competition drives niche partitioning/differentiation such that species don’t use the same resources in exactly the same way. Short term competition drives community dynamics Niche partitioning limits competition and increases fitness Over the long term this process can drive evolutionary change Ex: 5 species of warbler in eastern spruce forests use different parts of the spruce tree. (MacArthur 1958) Resources and conditions also vary over time. Species interactions change in response to environmental conditions and disturbances.

Answer 191

The positive effect of one species on another species Many species alter environmental conditions in ways that benefit other species Nitrogen fixation by Dryas spp and Alnus spp is critical to create the conditions required for the establishment of conifer forest. The structure of some organisms create favorable habitat for other organisms. Facilitation has received much less attention as a mechanism structuring communities. In general, facilitation is thought to be more common in stressful environments.

Answer 192

Biodiversity refers to the variability among living organisms from all sources, including terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part.

Answer 193

The Convention on Biological diversity defines biodiversity including the totality of variation occurring at three levels of organization: - Genetic variation occurring within populations and species - the number of species (species richness) present in an ecological community or in some other defined area; and - the assortment of communities occurring on any ecoscape, that is, the landscape of terrestrial environments and the seascapes of marine ones.

Answer 194

Within a population, differences among the phenotypes of individuals are based on two influences: - An underlying pool of genetic variation that has developed through a balance among the mixing of genotypes during sexual reproduction and the rates of mutation, genetic drift, gene flow, and natural selection - The variable expression of genetic potential known as phenotypic plasticity which occurs in response to the vagaries of environmental conditions

Answer 195

In sexual reproduction the genetic information of the offspring is distinct from that of the parents. While in vegetative (non-sexual) reproduction there is little variation between parents and offspring, and reproduction is analogous to the forming of clones. The largest example of clones is a trembling aspen that covers 43 ha consisting of 47,000 stems with an estimated weight of 6 million kg. These are connected with an extensive system of underground stems (rhizomes) and roots.

Answer 196

According to conservation biologists it is generally better for a population to have a large amount of genetic diversity. This allows for adaptive response to changes in conditions. Where as populations with lower diversity may be at higher risk from environmental challenges. Endemic species (locally distributed) especially can be vulnerable due to small, localized populations. This is also a problem for remnant populations of previously widespread species.

Answer 197

Population diversity aka ecotypic variation or provenance relates to the variation of genetic and phenotypic characters that exist among populations of a species. Each population share aspects of their attributes more closely with each other than with other populations of their species. More widespread species likely use a variety of habitats that lead to a great deal of population diversity. Population evolve quicker than species, but can also go extinct more easily.

Answer 198

Species richness refers to the number of species occurring in a specific area. While it comprises all plants, animals, and microorganisms in an area, ecological studies are usually restricted to a certain group of organisms of interest.

Answer 199

Canada has relatively low species richness due to its climate, and the fact that it was recently covered in ice and there hasn’t been enough time for many endemics to evolve in most of canada. Tropic humid forests support more species than any other habitats. Though some are not so rich. In Sumatra and Borneo lowland stands are dominated by Ironwood, comprises 96% of trees.

Answer 200

A third level of biodiversity is the variation of ecological communities that occur on a landscape or seascape. Some ecoscapes have only a few kinds communities. Others have a dynamic mosaic of many kinds of communities.

Answer 201

Food Medicine/Drugs Resources Fuel Other uses Aesthetic Value Intrinsic Value Can all be retain through sustainable practices

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