Yeety Flashcards
What is forest dieback?
Forest dieback is an episodic event characterised the premature ageing/death of trees without evidence of a single clear factor (CIESLA 1994)
2 facts about Earth’s forests please
They hold over 80% of our biomass and biodiversity
They cover up to 30% of our globe (FAO 2006)
What are the symptoms of forest dieback?
Dead trees/branches
Root necrosis
Chlorotic foliage
What are 2 examples of trees under threat?
Eucalyptus marginata/ Jarrah
Experienced a 1940’s Australian dieback where 20,000ha of trees were killed in the 70-80’s
The classic olive tree
A deadly bacterial pathogen is spreading, discovers in France in 2015 then Spain in 2017
What are 3 causes of forest dieback?
What do we need to consider?
Pests/diseases
Natural patterns of dieback
Climate change and positive feedback (Lucht 2006)
Synergistic effects
How do we combat forest dieback?
Irrigation and nutrient regulation
Monitoring / inspections
The removal of diseased individuals/areas
Disease control and DEFRA
What’s an example of a pest?
Mountain Pine Beetle of NW America
Why does the mountain pine beetle have significance?
It is native to NW America and attacks trees; damaging bark and carrying a deadly fungus
Climate limits their numbers, and they only attack mature trees which regulates biodiversity
However, a decadal outbreak has occurred, with the beetle spreading due to climate change (which also causes a bivoltine cycle)
13mha of trees have been killed, releasing 900mt of c02
How many species are dependant on ash trees?
44 (Mitchell 2014)
