REN3301 Revision Flashcards

Question

M3 - Why are species that live on islands more vulnerable than those on the mainland?

Answer 1

Vulnerable to catastrophic events that occur in a single place as there is nowhere else to go and the entire population would be affected. They also have small populations, narrow range, limited dispersal, etc. They often have not developed the capability to deal with potential threats (i.e. invasive species) the way mainland species do.

Answer 2

Values are enduring beliefs about appropriate conduct or end states of existence, representing worth in usefulness or importance to the possessor of those values. Ethics is the branch of philosophy concerned with right and wrong, establishing a basis for judging what is right and what is wrong.

Answer 3

i) Instrumental or utilitarian value says something is good if it provides the means for acquiring something else of value ii) Intrinsic value is good ‘in and of itself’, as in good for its own sake.

Answer 4

When attributing non-instrumental values in any biodiversity issue, the burden of proof is with conservationists (i.e. they must prove potential impacts or effects when only instrumental values are considered). When we consider non-anthropocentric values, the burden of proof is with developers etc. This consideration keeps with the precautionary principle of sustainability.

Answer 5

- Direct use values apply to components of biodiversity that are harvested directly and used by humans. These uses include consumptive use (local markets) and productive use (standard economic markets). - Indirect values are values assigned to functional aspects of biodiversity: non-consumptive (determined on service provided), option value (economic value of species or ecosystem in the future) and existence value (value we get from knowing a species exists).

Answer 6

i) anthropocentrism is the belief that nature exists for human benefit ii) biocentrism is life-centred; opposes anthropocentrism, focuses on intrinsic value of nature, particularly on individual species iii) ecocentrism (earth centred); provides a more holistic view in that the entire biotic and abiotic environment has an inherent value

Answer 7

It is a form of anthropocentrism, and assigns intrinsic value to all forms of life. It is an objective intrinsic value of nature by way of divine decree.

Answer 8

i) Provisioning services (i.e. food, timber, water and fibre) ii) Regulating services (affect climate, floods, disease, etc.) iii) Cultural services (provide recreational, aesthetic and spiritual benefits) iv) Supporting services (soil formation, photosynthesis, nutrient cycling)

Answer 9

Habitat change is the most significant anthropogenic driver of species extinction. This includes agricultural activity, urban expansion, and system modification.

Answer 10

i) Overexploitation of vegetation for domestic use (i.e. fuelwood and fencing), overharvesting of fish leading to ecosystem collapse and physical modification of ecosystems ii) Overgrazing of habitats leading to loss of grass cover, soil compaction, loss of soil fertility, etc. iii) Agriculture, which is harmful to soil ecosystem, freshwater ecosystems, cultivation of soils, nitrification, uncontrolled fire, river diversion for irrigation, etc. iv) Industrialisation, including extractive industries such as mining, contaminating soils and waterways

Answer 11

Fragmentation can be caused by natural disturbances (i.e. fire and wind) or human-induced (such as the clearing of natural vegetation for roads and agriculture). The two important consequences of fragmentation include a reduction in the area of the habitat type and a change in habitat configuration. Impacts may include increase in edge populations, smaller localised populations, loss of area-sensitive species, increased habitat vulnerability.

Answer 12

The unsustainable exploitation and harvesting of biotic resources, and essentially consists of some form of over-harvesting through hunting, fishing and collecting. It is a major cause of extinctions.

Answer 13

Can be native (indigenous local resident), introduced (non-native / foreign, bought in / dispersed from its place of origin, weed (plant growing in undesirable location) or feral (domesticated animal that has reverted to living in the wild)

Answer 14

i) Dispersal: organisms disperse to a new location, resulting in range expansion ii) Establishment and population increase in the invaded locality iii) Regional spread from initial successful population

Answer 15

The ecological opportunities – must not be hostile to growth or reproduction

Answer 16

i) An ability to occupy vacant niches ii) High survival rates iii) High adaptability iv) Defence mechanisms

Answer 17

It allows populations to tolerate a large range of environmental extremes, such as climatic extremes, heavy metal pollutants, herbicides, pesticides, etc.

Answer 18

i) Increased susceptibility to disease ii) Increased inbreeding iii) Loss of ability to respond to environmental change

Answer 19

Variation within individuals. An organism is heterozygous when two different alleles occupy the gene’s position on the homologous chromosomes.

Answer 20

Changes in allele frequencies that result from chance matings in very small populations.

Answer 21

When a population is reduced to small numbers, a demographic bottleneck occurs (an extreme example of genetic drift). It refers to the loss of variation at the level of individual genes that contribute to genetic diversity. When the population is small, genetic drift is accelerated, hence the bottleneck can reduce size of population quickly.

Answer 22

Inbreeding is the production of offspring by individuals related by descent (e. g. self-fertilization, brother-sister, parent-offspring, cousin matings, etc.). Inbreeding reduces reproduction and survival (reproductive fitness) – referred to as inbreeding depression.

Answer 23

i) Deterministic: Result of systematic forces that cause population decline (e.g. loss of pollinators, inability to find mates, inability to defend against predators). ii) Stochastic: The result of random fluctuations that have no systematic direction (e.g. extreme events, etc.)

Answer 24

i) Genetic: refers to changes in the genetic composition of a population unrelated to systematic forces (selection, inbreeding or migration / genetic drift). May reduce amount of diversity and increase chance of deleterious recessive alleles being expressed. ii) Demographic: refers to the variability in population growth rates arising from random differences among individuals in survival and reproduction within a breeding (reproductive) season. In absence of external factors, a populations chance of survival depends on balance between fecundity and mortality. iii) Environmental: refers to variation in birth (natality) and death (mortality) rates from one season to the next in response to weather, disease, competition, predation, or other factors external to the population. Environmental stochasticity is represented by temporal changes in a populations vital rates that often affect all individuals of given age or stage similarly. iv) Catastrophes: (i) are often distinguished as events at random intervals over time in which a large proportion of the individuals in the population die. (ii) even though catastrophic declines may occur very rarely, they have a large impact on whether populations are able to persist.

Answer 25

Fecundity (natality) and survivorship (mortality) are measurements used. The following equation can be used to determine population size after time: Nt+1 = Nt + (Bt + lt) – (Dt + Et) Whereby Nt+1 is population size after time (t) Nt is initial population size Bt is number of births over time lt is number of immigrants into population over time Dt is number of deaths over time Et is number of emigrants leaving population

Answer 26

Density-dependent factors vary as a function of population size or density and include intra-specific competition (breeding spaces, food, mates, foraging spots) and interactions between species (e.g. predation, parasitism, and competition). Density-independent population factors influence birth and/or survival in ways that have no relation to the density of individuals and include a wide range of environmental factors (e.g. climate, topography, latitude, altitude, rainfall, and availability of light).

Answer 27

Source habitats are 'good' quality habitats where reproduction exceeds mortality. Sink habitats are poorer in quality and mortality exceeds reproduction

Answer 28

A metapopulation is a group of discrete local populations ('sub-populations') which are interconnected by occasional migration events and that mutually affect each other.

Answer 29

The rescue effect is where migration between sub-populations can reverse local extinction or reduce the probability of extinction by bolstering a population that is reduced in size.

Answer 30

Endogenous disturbances are those to which community repeatedly exposed to over evolutionary time and tend to be 'natural' disturbances; exogenous disturbances are those which are 'novel' to the community and tend to be human-induced disturbances. Many endogenous disturbances are essential for maintaining overall ecosystem structure and function particularly in maintaining species richness in many ecosystems.

Answer 31

i) fragmented: modified or unmodified ecosystems destroyed over substantial parts of landscape; communities still occupy small proportion of landscape but tend to have abrupt boundaries ii) variegated: ecosystems still form significant component of the landscape matrix, although there may be areas where they have been destroyed; these ecosystems tend to have more gentle gradients of modification (i.e. ‘fuzzy’ boundaries) iii) relict: ecosystem largely destroyed with only very small areas containing elements of the modified communities remaining in the landscape.

Answer 32

A species whose impact on its ecosystem is disproportionately large relative to its abundance. This is a species whose presence or absence, or substantial increase or decrease in abundance, profoundly affects other species in the community.

Answer 33

i) time: temporal scales important for sustained conservation ii) space: includes spatial scale from habitats to landscapes and recognises ‘open’ systems iii) degree of inclusion: particularly in relation to the human dimension.

Answer 34

Stakeholders are those members of society who want to or should be involved in a decision or action because they have some interest or stake in it.

Answer 35

i) Hierarchial context – understanding of all levels of biological organisation required ii) Ecological boundaries – need to focus on natural (ecological) boundaries iii) Ecological integrity – includes all levels of ecological hierarchy iv) Information base – where sound scientific data is acknowledged as basis for decisions v) Monitoring – Linked to carefully chosen indicators that reflect management goals vi) Adaptive management – management is learning process and flexible in adapting vii) Inter-agency cooperation – cooperation among NGO, local, state & federal governments viii) Organisational change – change structures and methods of operation of resource management ix) Humans embedded in nature – we are a fundamental part of ecosystems & must be included x) Values – human values play dominant role in ecosystem management goals

Answer 36

Assumes that scientific knowledge is provisional and that management is a learning process and must be flexible enough to adapt to uncertainty.

Answer 37

Also called reserves, protected areas are clearly defined geographical space, recognized, dedicated and managed, through legal or other effective means, to achieve the long-term conservation of nature with associated ecosystem services and cultural values

Answer 38

The Convention on International Trade in Endangered species of Wild Fauna and Flora (CITES 1973) has been successful in restricting international trade in endangered species. The Convention aims to ensure that international trade in specimens of wild animals and plants does not threaten their survival.

Answer 39

i) Category Ia – Strict Nature Reserve: Protected area managed mainly for science. Area of land / sea possessing some outstanding or representative ecosystems, geological or physiological features and / or species. ii) Category Ib – Wilderness area: a protected area managed mainly for wilderness protection. Generally a large area of unmodified or slightly modified land and / or sea. iii) Category II – National park: mainly for ecosystem protection and recreation. Natural area of land and/or sea, designated to (a) protect the ecological integrity of one or more ecosystems for present and future generations, (b) exclude exploitation or occupation inimical to the purposes of designation of the area and (c) provide a foundation for spiritual, scientific, educational, recreational and visitor opportunities,

Answer 40

i) Comprehensiveness – includes many different habitat types of region / area ii) Representiveness – inclusion of critically threatened species and representative of the broader biodiversity iii) Adequacy – determination of minimum critical areas to ensure persistence over time. Must be adequate in size, contributing units, etc. iv) Efficiency – requires balance between costs and benefits; appropriately distributed v) Flexibility – providing for opportunities for expansion of reserve network vi) Risk spreading – spacing out reserves to minimise risk, balanced with connectivity vii) Irreplaceability – extent that inclusion preserves unique features viii) Connectivity – maintaining dispersal corridors for species ix) Protected area shape – minimising perimeter / edge ratios x) Minimising fragmentation – reducing edge effects

Answer 41

- The nature of the disturbance regime - Degree of spatial continuity - Dispersal capabilities of species - Population demographics - The characteristics of species concerned

Answer 42

- Habitat loss and degradation due to conversion of natural vegetation to pastureland and intensive agriculture - Overexploitation of natural resource The underlying causes were attributed to: population growth and immigration, the open nature of resources, insecure land tenure, weak law enforcement, local dependency on natural resources, illegal trade, cultural habits, weak incentives

Answer 43

I) Restoration: Bringing something (usually ecosystems) back to its former state. This often involves intensive management. II) Rehabilitation: attempt to restore any element of a structure or function – partial return to original state (passive or active) III) Reclamation: restoration work on most severely degraded sites – reclaim lost areas and make them function (active process) IV) Re-creation: attempts to reconstruct an ecosystem on a site so severely disturbed and degraded there is virtually nothing left to restore V) Recovery: leaving the system alone to recover with no intervention (passive process)

Answer 44

[SEE WORD DOCUMENT FOR DIAGRAM]

Answer 45

i) Restored ecosystem contains a characteristic assemblage of species that occur in reference ecosystem, providing appropriate community structure ii) Physical environment of restored ecosystem is capabale of sustaining reproducing populations of species necessary for continued stability iii) Restored ecosystem apparently functions normally for ecological stage of development iv) Restored ecosystem is suitably integrated into a larger ecological matrix or landscape, with which biotic and abiotic flows and exchanges v) Restored ecosystem is resilient enough to endure normal periodic stress events in the local environment

Answer 46

[SEE WORD DOCUMENT FOR DIAGRAM]

Answer 47

i) Setting realistic goals ii) Understanding community aspirations and policy framework iii) Understanding and addressing cause of degradation iv) Monitoring and assessing restoration work over a long time period using appropriate methodologies

Answer 48

- a clear rationale indicating the purpose of restoration project - an ecological description of the site designated for restoration - clear indication of goals and objectives - identification of appropriate reference ecosystem or suite of desired attributes of an acceptable end point - explicit plans, schedules and budgets for works to be undertaken - strategies for long term protection and maintenance of the restored ecosystem

Answer 49

Effective ecosystem management involves inducing a willingness among participants to give up some degree of control. It is a broad process involving 3 key components: - The recognition of ecosystem as appropriate management unit - Stakeholders are included in process of decision making from beginning - A flexible and ongoing adaptive management model used

Answer 50

i) A lack of knowledge about future conditions (i.e. weather and climate) ii) An imperfect understanding and representation of major processes in physical and biological models iii) Imprecise measurements of important physical and biological parameters iv) Randomness in models with stochastic components

Answer 51

i) Often too small to support all species ii) Often too small to contain normal patterns of disturbance that generate important processes of resource diversity iii) Often so fragmented that natural migration is unable to balance local extinctions iv) Often surrounded by hostile anthropogenic forces that harbour invasive species and degrade the environment v) Direct pressure for development

Answer 52

i) Proactive: proactive planning and strategies attempt to identify and deal with potential problems before they manifest as major problems ii) Need for wide array of professional and stakeholder viewpoints for iii) Management should be a means along the way, not as an end itself iv) Must be open to new ideas and not have preconceived ideations about pitfalls – progressive thinking is crucial

Answer 53

Adaptive management is a formal process for continually improving management policies and practices by learning from their outcomes, and requires planning, collaboration, careful measurement and analysis, and commitment to progressive change. Two key concepts are feedback (learning) and adjustment (adapting).

Answer 54

i) Assess: key gaps in understanding of the system are identified ii) Design: design a management plan and monitoring program iii) Implementation: put plan into practice iv) Monitor: indicators monitored to determine how effective actions are v) Evaluation: comparing outcomes to forecasts vi) Adjustment: models, objectives etc. are adjusted to reflect new understanding

Answer 55

- feedback – knowledge or data on the effects or results of an action, purposefully collected and used to improve future actions - adjustment – using knowledge and data provided through feedback to redirect subsequent action - experience – important of experience is implicitly recognised and change made to reflect experience – acknowledges learning-based approach to conservation management - consists of simultaneous attention to ecological, socio-economic and institutional concerns - includes large spatial and temporal scales - includes all relevant stakeholders - understands and deals with sources of uncertainty and risk, such as environmental stochasticity, independent effects and cumulative effects.

Answer 56

- explicit recognition of uncertainty about the outcome of management activities - deliberate design of management actions to increase understanding of the system - careful implementation of the policy or plan - monitoring key response indicators - comparing the outcomes to the objectives and predictions and - incorporating the results into future decisions.

Answer 57

- Reactive: change is driven by factors external to the management system, including politics, legal actions, public reactions, and research findings. - Passive: this approach is characterised by the implementation of a single policy on the assumption that the most likely hypothesis is true. - Active: this is characterised by accelerated learning through suites of policies and practices that can be compared in management experiments

Answer 58

[SEE WORD DOCUMENT FOR DIAGRAM]

Answer 59

i) Inherent complexity of systems and feedbacks. Understanding the interrelation and interconnectedness of population, ecosystem and landscape changes is important. ii) All biodiversity resides within landscapes, and despite placing higher value on wilderness and naturalness, humans affect all landscapes iii) Change is rapid and ongoing. Even if we eliminated all future climate change or land use, landscapes would still change rapidly.

Answer 60

- quality, depth and breadth of information available - complexity and non-linearity of processes whose outcome we are trying to predict - how far into the future we wish to carry predictions.

Answer 61

- stabilise then reverse human population growth - protect tropical forests and other major centres of biodiversity – bulk of biodiversity occurs in tropical forests and a few other hotspots around the globe. Immediate protection necessary to save as many species as possible. This may also impact on global warming by preservation of important ecosystem functions. - develop a more global perspective of resources, while solving problems locally wherever possible – political time frames are generally short (few years), human interest most often local – need to move away from ‘not-in-my-backyard’ phenomenon – although can act very effectively locally. - develop ecologically (steady-state) economics to replace growth economics. - modify human value systems to reflect ecological reality – all of the above points require a major change in human value systems – we need to drastically change the way humans perceive and value natural systems. This change in value systems could be manifest in several ways: (i) accepting limits to growth (ii) replace narrow anthropocentrism (iii) adopt ecological design principles.

Answer 62

i) Gene flow ii) Mutation iii) Genetic drift - demographic bottlenecl iv) Genetic drift - Founder effects

Answer 63

Habitat fragmentation dramatically increases the amount of edge relative to the amount of interior habitat. The microenvironment at a fragment edge is different from that of the forest interior (core area) (Fig. 9.3). Some of the more important edge effects are greater fluctuations in levels of light, temperature, humidity, and wind. It is generally recognized that reserves should be designed to minimize harmful edge effect as much as possible. Protected areas with rounded shape are more capable to minimize the edge effects than the long linear parks with the most edge