BIOL1131 Lecture Notes - Lecture 9: Controlled Burn, Understory, Storage Organ
7 Jun 2018
School
Course
Professor
Conservation Biology on Old Landscapes
• Conservation biology – a scientific discipline that carries out research on
biological diversity, identifies threats to biological diversity and plays an
active role in the conservation of biological diversity in all its forms.
• 2010 sampled Red List Index for plants under threat
o One in five plants are threatened with extinction (80,000 of
400,000 species)
o Tropical rainforest contains the most threatened species
o Gymnosperms are the most threatened group
o About 1/3 are so poorly known that we do not know their
conservation status
o The impact of humanity accounts for 81% of plant threats
o Single greatest threat is clearing for agriculture ~33% of
threatened species
• Predictive models are essential for managing biodiversity loss
• Over-generalisation: Forster’s latitudinal gradient in species richness
o Global biotic regions (plants)
o Higher species diversity in tropics
o Species diversity correlated with island size
• Landscape age as a predictor
o Old infertile uplands – 146
o Undulating terrain – 58
o Young fertile lowlands/wetlands – 24
o Old- climatically-buffered landscapes within 200kn of the coast are
where endemic plants are most concentrated in South WA
• Infertile (low phosphorus) soils are richer in total species
• A consideration of landscape age, geo-historical disturbance regimes
and soil fertility have important implications for the theory of
ecology and evolutionary and conservation biology
• YODFELs
o Young, often disturbed, fertile landscapes
▪ E.g. volcanic lands, windswept plains, steep slopes, wetland
floodplains, postglacial lands, coastal lands
o Plant characteristics
▪ Good dispersal mechanisms
▪ Good colonisers
▪ Often common and widespread
▪ Recently evolved rather than relictual
▪ Nutritional and biological generalists
▪ Tolerant of human disturbance
▪ Intolerant of prolonged fragmentation and rarity
▪ Low population-genetic and species diversity
o Conservation principles
▪ Plants will colonise unused lands
▪ Remnants of wild vegetation are interchangeable due to
low endemism
▪ Bigger is better (island biography, SLOSS debate)
▪ Ongoing forms of human disturbance are helpful
find more resources at oneclass.com
find more resources at oneclass.com
▪ Connecting fragmented populations with corridors is
desirable
▪ Sourcing seeds from wide areas for restoration is fine
• Do these principles apply to rare habitats such as those found in South
WA?
o OCBILs
▪ Old, climatically-buffered, infertile landscapes
• E.g. Pantepui (ighlands, South Africa’s Greater Cape,
Southwest Australia
▪ Found on passive plate margins
▪ Regions rich in OCBILs are richer in plant species
▪ Predictions
• Accentuated persistence of lineages and of long-
lived individuals
• Reduced dispersability, increased local endemism
and rarity
• Selection for heterozygosity in small populations
(The James Effect)
• Prolonged speciation at the margins (Semiarid
Cradle Hypothesis)
• Nutritional and other biological specialization
• Adaptation to saline soils
• Special vulnerability and resilience
▪ Special vulnerability
▪ Resilience
o Conservation guidelines
▪ Focus human disturbance away from these areas
▪ Provide space for biodiversity
▪ Minimize soil removal via bulldozing etc.
▪ Minimize importation of nutrients
▪ Minimize pollution causing climate change
▪ Minimize importation of alien plants, animals and diseases
and control where possible
▪ Minimize groundwater extraction
▪ In restoration of vegetation, plant local seeds or cuttings
• Conservation predictions
o Landscape-scale connections important for long linear YODFEL
plant communities e.g. streams
o The opposite applies to OCBILs
o Every remnant on OCBILs is valuable and may have unique
communities
o Persistence in small remnants may be strength of OCBIL plants
and less mobile animals
find more resources at oneclass.com
find more resources at oneclass.com
