Current threats to biodiversity pt2

• Over-exploitation 
• Invasive species
•Habitat loss & fragmentation

• Pollution (direct driver)
• Underlying drivers (underlying)
 •Global Climate Change  (direct driver)
• Synergistic effects of different factors (interactions)

The introduction of contaminants to the environment that disturb physical and biological systems 
(they're very heterogeneous)

• Many types and impacts.

– Toxic: normally lethal, affecting organism functions and may be persistent and may   bioaccumulate.

– Non-toxic: disturb behaviour and can be lethal. (noise pollution)

High concentration of S02 in the air, produced by factories, eliminated many lichen species.

lAir pollution is argely industrial, burning of fossil fuels- classic examples is in the NE where air pollution resulted in lichen  species decrease, partiulate matter clinges to trees. -

Dramatic and clear relationship between species diversity and distance from Newcastle tied to air quality which changes the colours of trees as a result to air pollution  (draw graph)

Many sources of pollutants:

• Regularly discharged by factories and sewage treatment plans.

• Sediments, fertilisers and pesticides from agricultural practices. 
(agricultural run-off, result of run off from multiple sources)

• Catastrophic surges as a result of accidents

High levels of pollution in one of the largest rivers in Europe, the Rhine, led to the loss of most of its freshwater invertebrate fauna 

water quality is very degraded 

Apex predators 

British raptors declined following the widespread use of DDT in agriculture since the early 50’s.

Eggs with high levels of DDT have thinner shells that break easily. (Newton et al. 1989) (affecting reproduction)

DDT is  Dichlorodiphenyltrichloroethane known for insectidal properties and environmental effects. 

US banned DDT under endangered species act which is a major factor causing the bald eagle (national bird of US ) to make a comeback. 

• Toxic for many non-target species.

• Last for long time and spread easily to large areas.
Long term effects:
affects many species
spreads large areas - DTT spreads to individuals up the trophic levels because they are digesting more and more individuals who may have ingested non-toxic amounts, this bioaccumulates.  Even the use of DDT is removed, it is still there in fatty tissues or water.

• Bioaccumulation/Biomagnification: toxin accumulates in living organisms and passes to their predators. Toxin becomes more concentrated the higher the trophic level.

Concentration of DDT magnified because eating so many small organisms 

This is the microbeads found in face wash.

Directly consumed by many species 

microbeads in facial wash- good tablespoon aggregate many beads. 

Does not degrade easily in environment over time masssive introduction into our food webs- then eventually being digested by fish- fish we end up eating

Swans try to eat plastic bag beep boop

Affects behaviour of nocturnal animals
(e.g., turtles, birds, mammals and insects)

Bit-  birds, insects and turtles 

adult egg laying done at night, turtles always lie on same beach- use moon as part of their compass, allows them to be directed- find right beach and for babies to head back to ocean. what is problematic is that we like costa rica beaches- set up hotels.

this causes light pollution - many animals rely on specific light hues- baby turtles don't know difference between hotel light and the moon- their guidance is disturbed 

(May) affects stress levels and communication behaviour

LOUD  near traffic, nest boxes been up in the woodland
- looking at how the blue **** respond to the stress of being near the noisy traffic road. how will baby birds communicate with their parents? or hear warning signs? mating communication?
how is this affected when the baseline noise is higher than it is in nature-
direct/indirect behaviours- affecting behaviours, diff pathways

Global Climate change 

Global average surface temperature has increased by 0.6 ºC during the past century.

Emission of greenhouse gases (e.g. CO2) from human activities are responsible for increase in temperatures.

Species differ in their thermal optimum and the range of temperatures they tolerate

diff species have diff thermal tolerance- some more comfortable, some operate optimally. (Draw graph)

thermal optimum different for diff species
yellow ones can tolerate only cooler temperatures and can only exist at narrow ranges
1) red hotttt2)
blue cold e.g. polar bears - yellow- highly specialised - narrow.
some more vulnerable to climate change than others

Species can adapt to climate change 

Species can change their phenology (life cycle events are related to temperature),

• Reproductive events will happen early (blooming happening earlier- bluebells)

• Insect will flight early

• Birds will migrate early (swallows

RIBS 

By changing their distribution (geographic and altitudinal distributions are limited by temperature)

• Expansions pole-wards and uphill (owards cooler areas  or uphill from lowlands to uplands towards cooler areas more successful - reproduce better)

• Contractions at warm limits and downhill (may become isolated to certain areas- contract to spot they can survive most easily)

In Britain, in a study of 385 plant species, first blooming has advanced by about 4.5 days

average- advance 4.5 days Uk have bluebell watches

In Britain, in a study of 10 common migratory birds species, they are arriving 12 days earlier now compared with 50 years ago

not 4.5 days like bluebell

what is the limit at which things can no longer migrate??? 
limits in species phenology- birds need set amount of time to mature

How long can they keep doing this for?

have a cut-off point

Many species are shifting their ranges northwards as a result of climate warming.

taxa written on bottom 

Polar & high elevation species:

Already at their maximum thermal tolerance. Nowhere to go if habitats become warmer.
- specially adapted cooler areas- nowhere cooler for them to go to
-what happens when new species begin to overlap when they were previously dispersed 

Tropical mountain species:

Narrow thermal tolerances that can easily be disrupted. (thermal optimum v narrow- cant adapt, simply die if you move 2degrees this way or that way)

Species with low mobility:

will not be able to shift their distributions coral reefs very slow to adapt- , can only exist at certain depths- need enough light- limited mobility. third mass coral reef bleaching event this year- starves corals- many corals are unable to recover even when temperature returns to normal. 

PUTS polar and high elevation species, unfixable, tropical moountain species, species with low mobility. 

high elevation cloud forest- really vulnerable climate change

number of days covered in mist decreased- dramatic effects on frog. cute golden toad frog :( extinct. result of change in temperature- stress in frogs- affects their ability to react to dangerous funghi. breeding through their skin- die out - dry

67 % of anuran species endemic to the American tropics have disappeared over the past 20 years

83% of the extinctions occurred after warm years

A mean global warming of

between 2.5 and 4.1 °C until

the end of this century is

expected - dependent on how

much greenhouse gases are

emitted into the atmosphere

during that time.

some species can adapt change phenology- but more vulnerable e.g. froggies become extinct 

Feeling the heat: Climate change and biodiversity loss

Many plant and animal species are unlikely to survive climate change. New analyses suggest that 15–37% of a sample of 1,103 land plants and animals would eventually become extinct as a result of climate changes expected by 2050.

what's problematic is the timeframe- our generation. will be lost in our generation 

Taxa: Mammals, Birds, Frogs, Reptiles, Butterflies, Plants.

Regions: Europe, South Africa, Mexico, Australia, Amazonia.

Table ->

Policy and institutional factors 
policy determines where you're building things)

Geist and Lambin 2002

arguing that underlying social drivers can predict that a change is going to happen e.g incentive policies to promote cod  SO if these social areas have these factors prediction of what will happe

• Drivers have affect biodiversity at unique scales:

– Spatial scales

• Climate change = spatial scale of a large region;

• Political change = scale of a nation or a municipal district.

– Temporal scales

• Sociocultural change = typically occurs slowly

• Economic forces tend to occur more rapidly

more of a systems thinking approach concerned with diff relationships, positive/negative feedback, underlying causes

Synergistic effects 

The impact of two factors together is greater than the sum of individual effects. 

real simplified policies REED policies reducing emissions deforestation

this matters because if we want to do something about these things we have to look at the intersecting links- if you want to protect farm- when road is put in- becomes harder and more epxnesive to protect 

political pressure (new roads)

Climate change (influences climate change- forest fires (spoken about on last slide)  = more habitat loss)

New resources for investment  (new demand for new infrastructure- hey we want a road they got  a road) 

Direct habitar loss & fragmentation  (direct impact- dissected forest- introduced high speed traffic- fragmented forest- road surfaces can be very hot , road kill - isolated two patches)  created access to an area that  used to be remote- hunters 

Facilitates over harvest of local resources (farming, food restaurants- agricultural change along road can get products to market)

linking table >>

Global strategy for road development

red- important for agriculture but no endemic species we wanna protect

need to think about this scale if we want to protect env

Mot butterflies in the UK have southern ranges
(Warming should benefit them!)

BUT

Most of them are habitat specialists 

maybe only eat nectar certain plants- maybe larvae only eat certain leafs

high bordered brown fritillary butterfly eats limestone plants- SSSI Arnside Knott

Semi-natural habitats have reduced dramatically during the last 50 years

1) Habitat specialists

Climate improve but there is no habitat available, so the species is not able to respond to climate change.

2) Habitat Generalists 

Climate improve and habitat available, so the species is able to respond to climate change.

• Required

– • Geist, H.J., Lambin, E.F. 2002. Proximate causes and

underlying driving forces of tropical deforestation. BioScience

52:143-150. URL: https://tinyurl.com/lk5rxuo

– Sodhi, N.S., Erlich, P.R. (Eds.). 2008. Conservation Biology for

All. Oxford University Press, Oxford. See pages 133-143,

153-158. URL:

https://conbio.org/images/content_publications/