BIOL3701 Lecture Notes - Lecture 2: Conifer Cone, Propagule, Bufotoxin
26 Jun 2018
School
Department
Course
Professor
Artesian Springs 2
Salt Pipewort: Should we burn our Mound Springs?
General
In Mound Springs
oConservation Park in SA
oPhragmites australis
Perennial grass
Increase in cover and abundance
oEriocaulon carsonii
Salt pipewort
Decreased by half
Shift from vents to tails where more vulnerable to grazing
Observation
Density of phragmites on springs is inversely correlated with that or
Eriocaulon
Temperature rises 3cm below soil – detrimental to Eriocaulon
Hypotheses
Eriocaulon experiences competition from Phragmites
Burning of springs will favour Eriocaulon
Why trial burn?
Recolonization by Eriocaulon of a spring burnt in 1993-94
Traditional indigenous practice of burning mound springs?
Conclusion
Winter burning:
oResulted in no immediate decrease in Phragmites root biomass
Eriocaulon plant death, or change in seed germinability
oResulted in decrease in Phragmites shoot density and height
BUT also decrease in Eriocaulon frequency cover after one year
oNo significant difference after 2 YEARS
Summer burning:
oRequires further investigation
Invaders
Invasive Species
Rabbits, cane toads, camels, donkeys, fire ants, bone seed, anthel pines,
goats, feral honey bees, sparrows, cabbage, cats, foxes, blueberries etc.
In Australia:
find more resources at oneclass.com
find more resources at oneclass.com
oInvasive species cause immense damage to:
Soils
Native plants
Animals
oAnnual production losses of millions of dollars
The Invasion Process
Invaders at Home
Can invasiveness be predicted from life history traits?
oBaker (1965, 74) concluded that ability to reproduce sexually and
asexually, rapid growth and phenotypic plasticity:
Promoted weediness in plants
oInvasive success of plant species in Czech Republic related to height,
life form, competiveness and taxonomy (Pysek 1995)
oInvasive introduced woody plants ten to be vegetative reproducers
Unfussy germination requirements
Log duration of fruit on plant
oColonists often “r-selected”
oNewsome and Noble (1986)
Invasive birds and plants tend to be “gap grabbers”, competitors,
survivors and swampers
General
Can invasiveness be predicted from life history traits?
oFreshwater fish invaders:
Tolerant to broad range of environmental conditions
Rapid dispersal and colonization
Aggressive behaviours
oMost vertebrate invaders:
Close association to humans
High abundance in range, size, broad diet, short generation
times
Ability of females to colonise alone
Tolerant to broad range of env. Conditions
Transport
Interactions with vectors
oMost long distance introductions are due to humans
Nursey stock, pet trade
oPropagule pressure
Introduction effort measure of number of individuals of a
species released into a novel region
Establishment
Correlation between traits needed for colonization
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
In mound springs: conservation park in sa, phragmites australis. Increase in cover and abundance: eriocaulon carsonii. Shift from vents to tails (cid:0) where more vulnerable to grazing. Density of phragmites on springs is inversely correlated with that or. Temperature rises 3cm below soil detrimental to eriocaulon. Recolonization by eriocaulon of a spring burnt in 1993-94. Winter burning: resulted in no immediate decrease in phragmites root biomass. Eriocaulon plant death, or change in seed germinability: resulted in decrease in phragmites shoot density and height. But also decrease in eriocaulon frequency cover after one year: no significant difference after 2 years. Rabbits, cane toads, camels, donkeys, fire ants, bone seed, anthel pines, goats, feral honey bees, sparrows, cabbage, cats, foxes, blueberries etc. In australia: invasive species cause immense damage to: Animals: annual production losses of millions of dollars. Can invasiveness be predicted from life history traits: baker (1965, 74) concluded that ability to reproduce sexually and asexually, rapid growth and phenotypic plasticity:
