Embed Size (px)
Citation preview
Aren't the Broads Brilliant !
Biodiversity:Winners and Losers
The Broads
A member ofThe National Park family
Roman times Today
Created by drainage and peat digging
© Mike Page
© Mike Page
Biodiversity
> 11,000 species
> 1,500 of conservation concern
65 depend on the Broads
5 species lost per decade
Our environment is changing
Potential flooding
Pressures
• • • •
Pressures
• Hotter drier summers• Warmer, wetter winters• Sea level rise• Extreme weather events –
frequency and intensity
• Migratory birds not arriving from Africa (cuckoo, nightingale)
• Plants affected by drought - habitats change
Examples
• 15 species of butterflies have spread since 1970s
• They appear earlier and have an extra generation during the summer
Examples
How to adapt ?
• Those species most suited to the new environment will flourish.
• E.g. If salt water incursions increase and the Broads becomes more brackish, sensitive freshwater fish species will be killed.
But brackish water species will flourish
Workshop Top Tips Features that may allow / prevent adaptation
• What habitats do the species live in?– Fresh / salt / brackish water– Restricted / rare habitats – Generalists (species that occur in many habitats)
• Will this habitat be affected by climate change?– Drying out / flooding– More salt water
• Will their food or predators be affected?
Your Task• Using the resources provided, and your own knowledge and
judgement, decide how the species populations will respond to climate change, in terms of distribution and abundance.
• 3 groups, each group will have 5 species• Each species may be winner or loser as a result of climate
change1. Research each species, decide how it may be affected by
climate change 2. Imagine climate change has happened (100 years in future)3. Consider where it might be found in the Broads
Species to find out about:
• Don’t go on to the next slides until the groups have had a chance to think and do the task.
The results
The next 3 slides summarise possible impacts to help work out the winners and losers ...
Group 1 Winner or loser?
Fen orchid
L Fragile population - needs clean calcareous water Threatened by:
• drought• increased acid rain• inundation from polluted water or sea water• lack of management
Brown rat W Very adaptable to different conditionsEats a wide variety of foodCan breed rapidly when conditions are right
Water lily ?L Needs pretty good water quality Can cope with range of water depths but not floods Cannot cope with salty conditions
Seaweed – eel grass
?W Needs salt water and tidal waterCould expand rapidly if conditions rightProne to pollution/ too much nutrient
Otter ?W Local populations thrive in freshwater though elsewhere in the UK they live on the coastNeeds clean water and can cope with variable levelsEats various prey but needs healthy populations.
Group 2 Winner or loser?
Herring gull
W Associated with the sea, but now moving inland Able to eat a wide variety of prey (and scavenge) Nest in a variety of locationsBeing able to fly they can escape adverse conditions
Grey seal
?W Live in salt water and need good prey levelsIf sea levels continue to rise, more water will become salty giving new opportunities Young - born in winter - vulnerable to more storms
Eel
?W Start life in the sea and move to freshwater and wetlands as they growOften move to new areas in times of floodsEat various prey but need clear passage to/fr the sea
Natterjack toad
L Very specialised - lives in wet areas that tend to dry out Can’t compete with other toads and therefore has restricted conditionsVariable rainfall and salt inundation will kill them off Can have masses of offspring if right conditions exist
Bittern
?L Need large areas of undisturbed reedbed and freshwater; Vulnerable to changing water levels flooding out the nest and losing that year’s youngster.
Group 3 Winner or loser?
Little egret
W Spreading through England from the south v possibly linked to warming conditionsCan find prey in fresh and salt waterCan fly away from adverse conditions
Fen raft spider
L Highly specialised spider - needs good quality, calcareous water with associated plantsSusceptible to flooding and salt water Drought conditions restrict them
Bats
?L Bats hibernate so longer periods of warmer weather could increase insect numbers and so help themDrought conditions generally restrict insectsFlooding is difficult for them - tho they can fly away
Swallowtail butterfly
L Needs milk parsley for their caterpillars - this is restricted to suitable freshwater fens (vulnerable to salt water incursion and flooding and drought) Can fly away but limited by lack of suitable wetlands
Tentacled lagoon worm
?W Tiny bristle worm lives in mud tubes in estuariesSeems to need brackish conditionsCan’t tolerate too much salt or pollution or changes in currents. More brackish conditions are likely, but the currents or too much salt might not help
