landscape ecology and ecosystem management Flashcards
(30 cards)
what is landscape ecology theory?
Originate in central Europe fusion of theoretical approaches in geography, landscape architecture, ecology and planning
The study of the main causal relationship between organisms and environment
Looked at the spatial patterns across landscape – a spatially explicit science
what is landscape ecology?
looks at the causes and consequences of spatial variation in surface features and biota across a range of scales
specifically focusses on the flow of energy, nutrients and species across the landscape
What can ecologists use to asses landscape ecology?
aerial photography
remote sensing satellites = provide images of earth that expand our view of large scale ecological patterns
connectivity =
the spatial continuity of habitat type across the landscape
explain how landscape structure can have an important effect on ecological patterns and dynamics?
influence how animals move
influences biogeochemical cycling – there are biogeochemical hotspots where rate of reactions are higher
Disturbance is constantly shaping landscapes – dynamic quality e.g. Fire
habitat loss and fragmentation example case study:
Lago Guri, Venezuela
Formations of islands with tropical dry forest surrounded by water due to the implementation of a hydro electric dam
allowed for oppertunity to study effects of habitat fragmentation
found on medium to small sized islands that lacked predators = islolation cased different species composition
and a different expression of the ecological community
what is habitat connectivity?
the degree to which the landscape impedes or facilitates movement
what are the two types of connectivity?
Structural connectivity: continuity among habitat patches
Functional: continuity of the actual use of the habitat by organisms (species specific)
what are the benefits of high connectivity?
High connectivity allows for optimum flow of organisms, biomass, and energy between patches (less vulnerable to predation across close proximity) = high functional connectivity
what are the key reasons for increased fragmentation of habitats?
- Key reason due to roads, land conversion, agriculture
habitat loss results in edge effects - what is this?
Exposes trees that were once surrounded by forests to higher temps, greater windspeeds, decreased soil moisture
These plants not equipped to handle these effects has dramatic effect on species composition and the environment
Increased tree mortality
Invasion of disturbance adapted beetles
Importance of connectivity example study name and date
Mueller et al (2014)
Mueller et al (2014) - connectivity study
Trumpeter Hornbill in south Africa
Investigated the effects of the role of large fruit eating birds in maintaining functional connectivity in fragmented landscapes
highlight that habitat fragmentation can reduce connectivity, negatively impacting biodiversity
However frugivorous birds can help mitigate these effects by dispersing seeds over long distances = this facilitates plant regeneration and gene flow between isolated habitat patches
These birds use stepping stone patches in order to maintain connectivity
Thus conservation strategies should prioritise protecting these birds species and their habitats to maintain landscape connectivity and ecosystem function
what is a habitat corridor?
linear patches that connect blocks of habitat
how can connectivity reduce the effects of habitat fragmentation?
by preventing isolation of populations
Can prevent isolation in populations that were once isolated
example of a connectivity project - habitat corridor
Trans-Canada Highway in Banff National Park.
Allow wildlife to cross over highway = mitigate killings due to cars
what are the concerns surrounding habitat corridors?
- may increase edge effects
- allow for invasive species to cross
- concerns over whether animals are actually using the crossing (noise pollution scares animals from crossing)
- increased risk of fire spreading
how can connectivity inform protected area design?
understanding the ways species interact with their landscape across space and time we can improve the design of protected areas and hopefully bolster conservation outcomes
Need to determine witch patches are essentially used by organisms throughout their lifetimes as well as the movement corridors or stepping stones that facilitate connectivity between these patches
Without the movement pathways the connectivity may be lost
marine connectivity example - name of study
Engelhard et al (2017)
explain the Engelhard study - Moreton Bay Australia
In Moreton Bay there are networks of no-take reserves these were revised in 2008 so track whether the reserves were successful in protecting fishes and coral reefs
studies 2 near threatened fish species - different mobility scales
Modelled potential connectivity using movement of fish species across the environment
found that of the 10 most important movement pathways - 7 were located outside the reserve zones
what have the findings of the Engelhard study suggested?
Connectivity for reef associated fishes in Moreton Bay currently insufficiently represented spatially and leads to insufficient protection
Rather than establishing more protected areas – existing reserves can be relocated to encompass essential mosaics and migration corridors
by home much has tree cover increased by in the last 40 years?
7%
what percentage of large vertebras have been lost
90%
Rewilding
restore (an area of land) to its natural uncultivated state (especially used with reference to the reintroduction of species of wild animal that have been driven out or exterminated)
