Post Midterm COPY

Question 1

whats the formula for toxic units (TU)?

Answer 1

TU = [exposure] / LC50 or EC50

Question 2

what is the community-conditioning hypothesis?

Answer 2

ecological communities retain information about unique events in their history; akin to the population bottleneck theory; may account for persistence of toxicant effects long after degradation

Question 3

Differentiate between observational and experimental studies

Answer 3

observational studies use biomonitoring, surveying, epidemiology. Experimental studies are manipulative, they change things.

Question 4

these ecosystems are typically antagonistic, some synergistic

Answer 4

freshwater

Question 5

explain the stability hypothesis for increased tropic biodiversity

Answer 5

tropics are more stable/predictable, species can specialize

Question 6

why are aquatic systems typically more sensitive?

Answer 6

because they have high NPP but low biomass

Question 7

in the river continuum concept, upstream is ___trophic and downstream is ____trophic

Answer 7

heterotrophic, autotrophic

Question 8

what is QSAR

Answer 8

quantitative structure-activity relationship: method used to attempt to group chemicals that are structurally related by their mode of action or chemical properties using stats

Question 9

what is the intermediate disturbance hypothesis?

Answer 9

researchers have found that exposure to intermediate disturbance or stress will maximize species diversity and stability

Question 10

explain the heterogeneity hypothesis for increased tropic biodiversity

Answer 10

tropics are more physically complex, more habitats for specialization

Question 11

Define community ecotoxicology

Answer 11

the study of the pollutant effects on species abundance, diversity and interactions in a common environment

Question 12

What is trophic cascade

Answer 12

Lethal or sublethal pollutant effects on predators, grazers, or scavengers leading to cascading effects at lower trophic levels

Question 13

What is the “salting out effect”?

Answer 13

increased salinity in water increases persistence of pesticides and POPs

Question 14

What are the shannon and simpson diversity indices individually sensitive to?

Answer 14

shannon to rare species, simpson to dominance

Question 15

These types of effects usually decrease organism abundance (indirect or direct)

Answer 15

Direct effects

Question 16

what is dose-ratio dependent deviation

Answer 16

shift between synergism and antagonism dependent on ratio of mixture constituents

Question 17

name four major ecosystem process that can be affected by contaminants

Answer 17

(1) decomposition (2) nutrient cycling (3) primary production (4) energy flow

Question 18

name 5 community characteristics that can influence stability and recovery

Answer 18

community complexity, community maturity, community history, recolonization ability, and life history traits of community members

Question 19

What is competitive release

Answer 19

When a pollutant resistant species wins or gains advantage. Niche overlap, interspecific competition

Question 20

describe component based mixture studies

Answer 20

use knowledge of individual toxicities of mixture components to predict/assess combined effect

Question 21

what are the 5 key features that determine severity of community resistance to disturbance?

Answer 21

(1) magnitude (2) frequency (3) duration (4) scale (5) timing

Question 22

These types of effects usually increase or decrease abundance (indirect or direct)

Answer 22

Indirect effects

Question 23

What are some problems associated with acidification in boreal lakes

Answer 23

Declines in DOC and DIC, reduced base cations, elevated dissolved metals, biota increased exposure to DNA-damaging UV-B radiation and metal toxicity, impairs biodiversity and certain processes

Question 24

what is macroecology

Answer 24

subfield of ecology that studies relationships between organisms and their environment at large spatial and temporal scales to characterize and explain patterns of abundance, distribution and diversity

Question 25

describe bottom-up mixture studies

Answer 25

identify most hazardous components of mixture to set thresholds; could apply uncertainty factor

Question 26

Define community ecology

Answer 26

the study of species abundance, diversity and interaction among all populations in a common environment

Question 27

what is the rivet popper hypothesis?

Answer 27

species are like rivets on airplanes with each species playing a small but critical role in keeping the plane/community airborne

Question 28

Name 4 global scale anthropogenic contaminants

Answer 28

(1) Organochlorines (2) Brominated flame retardants (3) Mercury (4) Perfluorooctane suflonate (PFOS)

Question 29

what is PICT?

Answer 29

Pollution induced community tolerance

Question 30

What are the 6 factors/filters controlling community composition and biodiversity

Answer 30

(1) historical and evolutionary (2) biogeographical (3) dispersal ability, colonization (4) physical environment (5) species interaction (6) anthropogenic

Question 31

what are the 6 leading hypotheses why amphibians are declining?

Answer 31

1) alien species 2) over-exploitation 3) land use change 4) global change (UV, warming) 5) increased pesticide use 6) emerging infectious disease

Question 32

What are five projected consequences of the "new climate"

Answer 32

(1) surface temperature rise (2) heat waves more frequent, long, intense (3) extreme precipitation (4) ocean warming and acidification (5) global sea level rise

Question 33

what are the pros and cons of MIXTOX?

Answer 33

Pro: allows for complex mixture analysis Con: complex and difficult, limited applicability in field settings

Question 34

What is the most important environmental policy in Canada?

Answer 34

CEPA (1999) Canadian Environmental Protection Act

Question 35

Define community

Answer 35

Communities are groups of interacting species that occur together at the same place and time and interact either directly or indirectly

Question 36

what are some major contaminants found in OSPW?

Answer 36

naphthenic acids, PAHs, benzene, phenols, heavy metals

Question 37

What is Rapaport's Rule of environmental gradients?

Answer 37

species found in more variable habitats have greater tolerance than those in more benign habitats; Hypothesis that states that plant and animal ranges are generally smaller and richness is higher at lower latitude/elevations than at higher latitude/elevations

Question 38

what is dose-level dependent deviation

Answer 38

shift between synergism and antagonism dependent on TU of mixture constituents

Question 39

explain the evolutionary time hypothesis for increase tropic biodiversity

Answer 39

tropics are "older", not subjected to recent glaciation, thus more time for speciation

Question 40

multiple stressors in an organism can cause: (3)

Answer 40

1) increased contaminant exposure 2) increased susceptibility 3) reduced adaptive capacity

Question 41

What are four reported consequences of climates change

Answer 41

(1) rising temperatures (2) increased melting/thawing (3) rising sea levels (4) increased weather severity

Question 42

explain the productivity hypothesis for increased tropic biodiversity

Answer 42

tropics have more primary productivity, more food, greater food web complexity

Question 43

Name two mechanisms of indirect pollution impacts on communities

Answer 43

Competitive release and trophic cascade

Question 44

what is the redundancy hypothesis?

Answer 44

species with similar niche are considered redundant because they could be eliminated or replaced by others with no loss in community function

Question 45

what are the 6 key features that determine resilience from disturbance?

Answer 45

(1) magnitude (2) frequency (3) duration (4) scale (5) timing (6) physical features of affected habitat

Question 46

these ecosystems are typically synergistic or additive

Answer 46

marine

Question 47

give three examples of environmental gradients

Answer 47

pH, elevation, temperature

Question 48

on a species abundance curve, what do the y-intercept, the length of x, and m represent?

Answer 48

y-intercept indicates dominance, the length of x indicates richness, the m indicates evenness