ECOL212 notes - Steph, Linn Hoffman, Lisa Ellis PDF

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Steph, Linn Hoffman, Lisa Ellis ...

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ECOL212 LECTURE 2- APPLIED PHYSIOLOGICAL ECOLOGY Autecology: individual/species (physiology, behaviour) Population ecology: population, disease Community ecology: disease, community translational ecology: ‘real world’ What is physiological ecology? • Also termed ecophysiology • Involves understanding the interaction between organisms and their environment • Can be scaled up to understand how individual physiological tolerances influence distributional dynamics What can it tell us about organisms and their function? • Reproduction • Survival (and physiological tolerances) • Adaptation and acclimation • Thermal requirements and preferences • Stress physiology • Photosynthesis/metabolism real life q’s-> e.g. by understanding physical tolerances we can anticipate effects of climate change on species -construction affecting distribution/migration -stress -less energy for reproduction -translocating -> associated with migration, knowing thermal requirements is important -climate niche and human impact -ecotoxicology Example 1: Photosynthesis of lichenson retention trees Green tree retention -clear cutting removes dependent biodiversity e.g. lichens, epiphytes etc. -> response: green tree retention to speed up regeneration of logging forests -A number of large trees are retained during felling to increase biodiversity and enhance regeneration of forested sites. -Widely accepted technique in commercial forest management -Study in Estonia -common in North America, Estonia

-‘life boating’ of species Biodiversity is one thing, but function is another – are the organisms that remain functioning at the same level? dependent on factors affected e.g. light level, humidity, incoming solar radiation Lichens Fungi/algal/cyanobacteria mutualism How do lichens respond to the abrupt changes in microclimate after harvesting – the increased light, higher temperature and lower humidity? measured by Chlorophyll fluorescence parameter: Fv /Fm, this measures photosynthetic potential control had a higher photosynthetic potential than treatment (felling) difference changes depending on lichen species

Example 2: Predicting invasion risk from physiological tolerances Ecological niche concept The ecological ‘niche’ that a species does/can occupy Can include: - Habitat - Refuge - Food - Physical environment ecological niche modelling: Calculates the realised niche of a species based on where it occurs and the physicochemical properties of those occurrences has been used for translocating takahe map can replace a lack of historic knowledge of range Example 3: Western corn rootworm (Diabrotica virgifera virgifera) • Worms feed on roots, adults feed on ears, leading to a reduction in yield of maize crops by around 15% • Originally from USA, recently introduced to Europe

• Where may this pest be able to establish? • What locations are at risk from this pest species? • Niche factor analysis -> identify environmental variable determining the niche of a species, by using distribution to compare to environmental variable e.g. temperature • use to measure risk of establishment in new geographic environment • application: biosecurity effort increase in high risk areas e.g. near airports more applications: invasive species/pathogens translocations e.g. tuatara (especially with regard to sex ratios)

The ecology of stress Stress involves the activation of the hypothalamic–pituitary–adrenal axis Two types of stress: acute (fight or flight) – and chronic (longer-term, low levels of stress) Even as humans, we know that stress can have negative effects on health – same is true for animals: -Increased susceptibility to disease, lowers immune system -Interfere with reproduction -Metabolism -Survival Glucocorticoid metabolites can be sampled from blood (invasive), but also from faeces (noninvasive) to measure stress levels. Example: Reproductive failure in the American kestrel (Falco sparverius) Strasser, E.H. and Heath, J.A. (2013) Reproductive failure of a human‐tolerant species • As human populations encroach on wildlife populations, what impact does this have on wildlife populations? • Kestrels are considered ‘humantolerant’ – occupy urban areas • What impact does urbanisation have on this species? Urbanisation results in higher rates of reproductive failure of nests Why would this be? • Traffic noise unlikely to impact reproductive behaviours (e.g. courtship, mate-choice) • Nest initiation time not affected by disturbance score • Abandonment occurs during incubation, so not to do with parent-offspring interactions or juvenile survival. Management recommendations for reducing noise In protected areas – noise reduction methods could be implemented: • Sound barriers around roads • Reduce speed limits or traffic volume in sensitive areas In urban areas, the challenge is greater: -> Economic incentives that encourage engineering innovations that result in quieter roads, vehicles Example 4: Non-lethal impacts of tourism on wildlife Ellenberg, U., Setiawan, A.N., Cree, A., Houston, D.M. and Seddon, P.J., 2007. Elevated hormonal stress response and reduced reproductive output in Yelloweyed penguins exposed to unregulated tourism. General and Comparative Endocrinology, 152(1), pp. 54-63. • Ecotourism activities often involve increased activity of humans around wildlife • What impact does this have on their function? Collected blood samples from hoihoi (Megadyptes antipodes) at two sites: • Green Island – permit only access, low tourist activity • Sandfly Bay – presence advertised, high tourist activity (unregulated)

Penguins at Sandfly Bay ‘stress’ more easily -> Birds exposed to unregulated tourism appear to display a more sensitive stress response. Birds at Sandfly Bay have learned to see humans as a more eminent threat compared to those at Green Island. Corticosterone levels affect fledgling weight-> Feeding could be interrupted by human traffic at Sandfly Bay, leading to overall lower fledgling weights Management recommendations? • Promotion of specific penguin viewing sites to concentrate impacts will fail if tourism is unregulated • Visitor education and management is required. • Minimise tourism in breeding areas, and reduce disturbance at penguin landing sites. • Encouraging more predictable behaviour by visitors could promote habituation and reduce negative effects of tourism.

LECTURE 3: Behavioural ecology (aka ethology) Involves understanding how animals behave, interact (social interactions, mating patterns), or utilise the environment/landscape (e.g. different habitats) • Key way in which organisms can mitigate negative experiences with their environment (e.g. escape/move/disperse) What can it tell us about the ecology of species? • Activity patterns • Social behaviour • Courtship behaviour and mating systems • Home ranges and habitat selection • Animal ‘personality’ • Territoriality & contests/fighting • Sexual selection -knowing behavioural aspects important for management and conservation e.g. for translocations territoriality- space-limned species e.g. tigers impacts of urban environments -> personality composition of species social behaviour changes study designs pest management -> biological controls e.g. disease spreads (K5 virus for rabbits) -activity patterns and budgets are an important aspect of how animals survive and function Example 1: Tourism impacts on activity patterns of sharks Huveneers, C., Watanabe, Y.Y., Payne, N.L. and Semmens, J.M., 2018. Interacting with wildlife tourism increases activity of white sharks. Conservation physiology, 6(1), p.coy019. • Cage-diving: great white sharks are attracted to tourists using bait or sound emitting devices • Altering animal behaviour: what impact does this have on great white sharks? -Activity budgets? -Energy balance? -Fitness and survival of populations? Measuring activity using accelerometers • Accelerometers are tri-axial devices that record momentum (much like your fit-bit or smart-watch) in different directions • Tagged 10 sharks & recorded their behaviour across different contexts •

Lecture 5: Applied Disease Ecology - What is disease ecology? • transmission methods and life cycles • dynamics and seasonality of disease • heterogeneity and drivers of transmission • impacts of disease on host populations - How are diseases transmitted? • directly e.g. coughing, physical contact • indirectly - e.g. faecal-oral, i.e. parasite in faeces, infects pasture, eaten by intermediate host e.g. cat eating infected small mammal, - environmental reservoir e.g. waterways with geardia - vector borne e.g. malaria with mosquitos • density dependent transmission depends on the density of the host and the transmission method, this is true for lots of parasites/diseases spread directly -> not a good model for vector borne disease • frequency dependent transmission e.g. STI’s, vectors -> occur regardless of density - Population dynamics of disease e.g. red grouse, host population = grey, disease = red

- Applications of disease ecology • disease as a conservation concern- understanding the role of disease in population declines, and how we might manage these threats

• disease of economic or human importance- understanding the transmission of diseases and their management

• diseases as biocontrol agent- how can we obtain maximum impact when using disease as a biocontrol

- e.g. 1 Devil Face Tumor Disease and the plight of the Tasmanian devil (conservation) • transmissible cancer- technically not a disease but behaves like one • dotted line = % hosts with disease • solid line = population density • animals are aggressive, so behaviour leads to unlikely density-dependent behaviour of disease

• management options: - culling -> reducing population density so infection is slower, removing infected individuals.

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When this was modelled it was found that 80% of the population would need to be removed quarterly, which is inappropriate for an endangered species - insurance populations: best options for devils currently, disease free devils transferred to offshore islands, - vaccines have been developed and trialled - released vaccinated devils back into Tasmania, but many got hit by cars as they are possibly more naïve to traffic than wild devils. e.g. 2 controlling bovine tuberculosis by managing wildlife reservoirs (disease of economic importance) • spread by possums in NZ, badgers in UK- carried by wildlife species, transmitted to cattle from contaminated food, or direct interaction with badgers • culling is technique used - ‘breakdown’ is when a disease is detected in a herd - breakdown- 1 cattle is infected, the rest of the herd is culled - fewer breakdowns when badger culling occurs, but outside culling zones there is an increase - assumption of density dependent selection is that interactions ore random- by culling populations there is an increase of badger-badger interactions • controversial as badgers are native to the UK, evidence of efficacy of culling in controlling Tb is mixed- yet in the UK the government proposed expanding culling program • badgers are social animals, so there is the issue of disruption to social structure by culling • HR= home range (territory overlap) e.g. 3 using disease as a biocontrol- rabbits and RHDV in Australia and New Zealand • significant agricultural pest in Australia and NZ • rabbits have an economic influence • flies are a mechanical vector: move virus from dead rabbits to live rabbits as the flies eat the carcass, defecate on living rabbit, and then the rabbit cleans itself and becomes infected first imported into Australia in 1991, experimental trials in 1995- accidental release into • mainland Australia was unable to be contained • New Zealand government rules against its use but it ‘appeared’ anyway in Central Otago in 1997 • Farmers perpetuated spread across South Island by preparing infected baits • disease has been effective in controlling rabbit populations- reduced rabbit population by ~85% • good at population supression, but will not eliminate pests altogether • resistance builds up after time, disease becomes less virulent = efficacy declines

• myxomatosis = virus affecting rabbits, relies on a mosquito vector, in 70’s fleas were introduced

- challenges of disease as a biological control • host specificity • evolution of resistance/virulence • ethical concerns • effects on other components of ecosystem • costs of research and development • e.g. carp- pest fish species, impact structure of ecosystems, have a large biomass which becomes a source of nutrition when they die

Lecture 6- Applied Community Ecology - What is community ecology? • More than one species; looking at the organisms that occupy and ecosystem, and how they interact community structure- what species are there and what are their relative abundances • trophic relationships (e.g. hosts, parasites) and food webs • ecological interaction networks • - What can we learn from applying community ecology? • measure the impacts of disturbance in the structure of ecological communities • measure the success of ecological restoration activities • understand the impacts of disturbance on ecosystem function/ecosystem services • conservation either focussed on place or species, we assume this provides additional protection to the ecosystem • new theory suggests that we focus on networks and processes/community ecology instead as it is more effective • look at interactions instead of assemblage - e.g. 1 does livestock trampling impact snail communities? • how do land use changes impact the structure of ecological communities? • forest fragments adjacent to farmland can be used as a livestock shelter • what impact does this occasional use have on ecosystems? • Used a BACI designs (Before, After, Control, Impact) • 3 types of trampling: - soil only - soil and litter - soil and half-litter removes Four levels of trampling • - 0 (control) - 2 trampling events - 4 trampling events - 6 trampling events • trampling alters community structure

• fencing to keep cattle out? - even low levels of tramping can have significant effects on snail community structure

-fences are advisable to keep cattle out of remnant forest -~77% of framers value forest fragments as a livestock shelter as well as for their conservation value- mutually exclusive •ecological interactions -community structure- tells us about how a community is composed -but doesn’t necessarily tell us how the community is functioning -measure the interactions in an ecosystem -diagram: each circle represents a different species -e.g. 2 pollination networks in organic vs nonorganic farming •organic practices mainly fulfil a consumer demand, but should hold benefits for ecosystems as well • how do different farming practices affect

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plant-pollinator interactions? 2x100m transects were walked, and pollinator-plant interactions were recorded it was found that there was no effect of farming type on species richness of pollinators hoverflies and bees were more diverse in the edges of the filed than in the centre more interactions in organic farms than in conventional farms visitors per plant higher in organic farms- could be more vulnerable to disturbances higher rates of pollination (fruit production) in organic farms organic pollination networks are more connected, and lead to a better fruit-set than conventional farms networks still small and unstable (vulnerable to disturbance)

- e.g. 3: predicting changes to food webs following ecosystem perturbation • ecological networks can also be used to represent trophic interactions • what happens to these networks when we remove one part of the system? e.g. rabbit suppression from RHDV

• direct and indirect impacts • e.g. in AUS increased competition with kangaroos and increased predation by cats at higher rabbit removal rates

•both cats and foxes decrease with increasing rates of rabbit control due to reduced food availability •top predator numbers increase with increases in rabbit control- reduced rabbits increases kangaroos which are preferred prey for dingoes, increase in digress reduces abundance of other predators e.g. cats and foxes •Top down and bottom-up influences on network changes: -bottom up: reduced rabbis increases food for kangaroos, which increase abundance and cause increase competition for food with small mammals - top down: increases in dingoes reduced the abundance of mesopredators, compounded by reduction of food (rabbits) available)

- Ridding NZ of possums, rats and stoats by 2050- what will the ecological consequences of this be?

Lecture 7: Translational Ecology - The scales of applied ecology • individuals-> populations-> communities • ecologists -> users of ecological knowledge • research to form political changes • translational ecology: mutual multi-way learning, ongoing engagement, promotes trust and buy-in. involves understanding of the social, ecological, and political contexts of the issue through • dialogue with stakeholders • ecologists need to know what research is the most relevant • both applied and translational ecology are use-inspired, but where applied ecology may have implications for management, it is developed in isolation of stakeholders, wherever in translational ecology stakeholders are involved in the process, not just delivered information at the end • stakeholders may include: businesses/industry, local iwis, councils, landowners, NGO’s, ecotourism operators, communities and reserve managers etc.

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process behind translational ecology varies depending on the project not all translational ecology projects will utilise all of these principles it depends of the context/research problem all require collaboration -> co-developed knowledge communication important were different types of scientists are working together decision framing important when non-science agencies involved process is important when diversity of stakeholders is involved e.g. Agricultural conservation methods in Saginaw Bay - a program developed to test and implement methods to enhance ecosystem health in an agricultural landscape - involves farmers, scientists, industry associations etc. implementing translational ecology - as decision/implementation and ecological complexity get more complex, translation becomes increasingly important conflicting values and priorities - understanding the decision context is important - opportunity for joint ‘fact finding ‘ - e.g. californian spotted owls conservation vs fire hazard of having dense tree stands what does a translational ecologist look like? - multidisciplinary knowledge • ecology, law, economics, government, ethics, sociology, business management - practical skills • communications, decision science, risk assessment, project management, conflict resolution, group facilitation, scenario planning - personal aptitudes • patience, humility, empathy, ,leadership, sociability, commitment to inclusivity and diversity, commitment to process predator free nz - stakeholders: pet owners, tourism operators, farmers, hunters (1080), iwi (taonga species) key points - if we want our research to make a difference, we need to engage the end-users from the start, and the end users need to be receptive to the idea (education and communication) - requires continued maintenance of relationships, not just one-off consultation - co-developed knowledge gives stakeholders buy in and ownership of the process- better engagement "

Lecture 8- Lisa Ellis Ecological Values

- Why it’s important to have a defensible argument - Planetary boundaries (Steffen et al. 2015) • how far we can push the planet’s systems • flourishing in unstable conditions • using proxies to measure e.g. genetic diversity -> extinction rate • results: trade off between short term benefits and long term harm - A first simple argument • begin with a first moral premise, this doesn’t have to be defended - it may not always be true but needs to be asserted to make a productive argument • second premise is factual/empirical, if found to be untrue the argu...