Steve 2 Flashcards
What is an algorithm
A step by step procedure for calculations. A finite list fo well-defined instructions
What are SPAs designed to do
Site Prioritisation Algorithms are designed to select optimal sites in a reserve network based on predefined criteria and in relation to resources available to a conservation plan.
Practically what sites do SPAs use
- Minimum area approach- requires all species to be represented in a reserve system that has the smallest possible area. If you are being frugal- protect all the species that you want and which parcels of land are smallest/cheapest with them in
- Maximum coverage approach- the maximum number of species to be protected in a reserve network that is limited by cost
What are the theoretical approaches to SPA
Richness algorithm- aka greedy algorithm. Start by selecting the sites that hold the greatest diversity available and then add sites that are the next most diverse. Could prioritise areas in 1 or 2 of the most biodiverse areas of the world. May have high species richness but may miss some species that don’t occur in any other protected area (eg polar bear)
Complementarity- Vane-Wright et al (1991). defined by the addition of sites that complement previously selected sites by adding the greatest number of new species to a network. Look at adding value. Does not reject richness the number of different species in a site enter into the computation, though weight given to each species declines as its representation in the selected sites increases. DECLINE IN WEIGHT INVOKES COMPLEMENTARITY –> reduces redundancy
Rarity approach- select sites dependent on their irreplaceability in terms of the rarity of species, or other factors such as endemism within the site. This is what’s been happening for the last hundred years really
Why do algorithms have flaws
Susceptible to leaving out some species and over-representing others eg what algorithms would protect a polar bear? lives in low richness environment but still rare
Example of an ealry alogrithm
Terborgh and WInter (1983) chose sites that were identified as hotspots of endemism so as to create a cost-effective reserve network
–> likely to have large overlap of spp betwen reserves therefore redundancy
Kirkpatrick (1983) used an iterative stepwise approach tat recalculated the relative diversity of each remaining site after each stage of selection, ie richness algorithm with the principle of complementarity
How can we calculate SPA
Heuristic- selective step-by-step approach
Although they are designed to reach efficiency heuristics rarely reach, or can detect theyve reached, an optimal solution. Once they’ve gone off of picking the optimal solution then they get caught in local optima
Simulated annealing- an interactive optimisation process. Starts with a randomly determined reserve network and then explores trial alternatives by randomly adding or deleting sites at each iteration. They reach an optimal solution more often than heuristic.
Optimality is often only practical from a theoretical point o view. For example SA randomly drops out sites that you may already have in your network.
Example of SPA
Rottnest Australia- came up with possible marine conservation solutions. It says lots of little areas should be protected around the island. But from a management point of view protected lots of little areas v difficult. So instead selected sites based on which ones were most connected to other sites. Protected as much as SPA suggested.
Difference between SCP and SPA
By definition, SCP must involve things outside of SPAs, as the latter need initial objectives in order to know what to prioritise protecting, and implementation and longer term evaluation is beyond the scope of SPAs.
What is an irreplacebility score
Based on the extent an area could be swapped for another
What is SCP
Systematic Conservation Planning
Aims to minimise conflict with other land users - each planning unit can be given a value for other land uses or its risk of being cleared eg for agriculture. Software then identifies conservation landscapes that meet the targets whilst minimising conflicts with other user groups.
SCP, as it was originally described, was composed of six different stages: collection of data, identification of conservation goals, evaluation of the existing protected area network, design of expansions, implementation of conservation action, and long-term maintenance of biodiversity in the network. Since then, the operational model has been expanded into several different variants. Conservation actions applied inside SCP include establishment and expansion of reserve networks and allocation of habitat restoration and management.
What is opportunity cost data
Opportunity that you could reap from an area if you were to use it for its full potential - eg agriculture to produce wheat to sell or protected area
Can give sites opportunity cost values that can be used in algorithms.
SPA and BAP
SPA ZONATION was used to identify locations where UK Biodiversity Action Plan spp of mammals, birds, herptiles, butterflies, and plants occur in concentration populations with high connectivity.
Found plants and birds BAP species do not occur in the same places so use of one taxonomic group is not a surrogate for another
Species with narrow geographic ranges were most effective at prediction cons success for other species. Prolly because they represent a range of environmental conditions required by other spp
How can you measure cost effectiveness
benefit divided by the cost
What are current plans for expansion of global PAs
Governments have agreed to expand global PA networks to 17% of land surface by 2020. However, PAs often biased towards cheap sites away from important areas of biodiversity.
17% of vertebrates not in a single PA.
85% not adequately covered by current PA networks.
Using SCP expanding current protected sites to 17% of the cheapest piece of land would only increase protection by 6%. However, spending 1.5% the cheapest solution would increase vertebrate protection 5 fold
