Journal of Biosciences

, Volume 27, Issue 4, pp 361–384 | Cite as

Persistence and vulnerability: Retaining biodiversity in the landscape and in protected areas

  • K. J. Gaston
  • R. L. Pressey
  • C. R. MargulesEmail author


An objective of biodiversity conservation activities is to minimize the exposure of biodiversity features to threatening processes and to ensure, as far as possible, that biodiversity persists in the landscape. We discuss how issues of vulnerability and persistence can and should be addressed at all stages of the conservation planning and implementation process. Procedures for estimating the likelihood of persistence and for measuring degrees of vulnerability at different spatial and temporal scales using subjective assessments, rules of thumb and analytical and simulation models are reviewed. The application of information on vulnerability and persistence to conservation planning and management is discussed under the headings of natural dynamics, replication of protection, levels of representation, source and sink population structures, refuges and critical resources, reserve design, habitat fragmentation and levels of management.


Design of protected areas persistence of biodiversity features species vulnerability threatening processes 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Austin M P, Cunningham R B and Fleming P M 1984 New approaches to direct gradient analysis using environmental scalars and statistical curve-fitting procedures;Vegetatio 55 11–27CrossRefGoogle Scholar
  2. Avery M, Gibbons D W, Porter R, Tew T, Tucker G and Williams G 1994 Revising the British Red Data list for birds: the biological basis of UK conservation priorities;Ibis 137 S232-S239Google Scholar
  3. Beier P and Noss R F 1998 Do habitat corridors provide connectivity?;Conserv. Biol. 12 1241–1252CrossRefGoogle Scholar
  4. Belovsky G 1987 Extinction models and mammalian persistence; inViable populations for conservation (ed.) M E Soulé (Cambridge: Cambridge University Press) pp 35–57Google Scholar
  5. Benson D H and Howell J 1990 Sydney’s vegetation 1788-1988: utilization, degradation and rehabilitation;Proc. Ecol. Soc. Aust. 16 115–127Google Scholar
  6. Berger J 1990 Persistence of different-sized populations: an empirical assessment of rapid extinctions in bighorn sheep;Conserv. Biol. 4 91–98CrossRefGoogle Scholar
  7. Benson J 1991 The effect of 200 years of European settlement on the vegetation and flora of New South Wales;Cunninghamia 2 343–370Google Scholar
  8. Bibby C J 1994 Recent past and future extinctions in birds;Philos. Trans. R. Soc. London B344 35–40Google Scholar
  9. Boecklen W J 1991 Theoretical and empirical biogeographic models in conservation; inLatin American mammalogy: History, biodiversity, and conservation (eds) M A Mares and D J Schmidly (Norman: University of Oklahoma Press) pp 150–166Google Scholar
  10. Boecklen W J and Simberloff D 1986 Area-based extinction models in conservation; inDynamics of extinction (ed.) D K Elliott (New York: Wiley) pp 247–276Google Scholar
  11. Bowman D M J S and Whitehead P J 1993 Is conservation biology the dismal science?;Aust. Nat. Hist. 24 72Google Scholar
  12. Boyce M S 1992 Population viability analysis;Annu. Rev. Ecol. Syst. 23 481–506CrossRefGoogle Scholar
  13. Braithwaite L W 1983 Studies of the arboreal marsupial fauna of eucalypt forests being harvested for woodpulp at Eden, New South Wales. I. The species and distribution of animals;Aust. Wildl. Res. 10 219–229CrossRefGoogle Scholar
  14. Braithwaite L W, Belbin L, Ive J and Austin M 1993 Land use allocation and biological conservation in the Batemans Bay forests of New South Wales;Aust. For. 56 4–21Google Scholar
  15. Braithwaite L W, Binns D L and Nowlan R D 1988 The distribution of arboreal marsupials in relation to eucalypt forest types in the Eden (NSW) Woodchip Concession Area;Aust. Wildl. Res. 15 363–373CrossRefGoogle Scholar
  16. Braithwaite L W, Dudzinski M L and Turner J 1983 Studies of the arboreal marsupial fauna of eucalypt forests being harvested for woodpulp at Eden, New South Wales. II. Relationship between the fauna density, richness and diversity and measured variables of habitat;Aust. Wildl. Res. 10 231–247CrossRefGoogle Scholar
  17. Braithwaite L W, Turner J and Kelly J 1984 Studies of the arboreal marsupial fauna of eucalypt forests being harvested for woodpulp at Eden, New South Wales. III. Relationships between faunal densities, eucalypt occurrence and foliage nutrients and soil parent materials;Aust. Wildl. Res. 11 41–48CrossRefGoogle Scholar
  18. Brown J H 1984 On the relationship between abundance and distribution of species;Am. Nat. 124 255–279CrossRefGoogle Scholar
  19. Bunin J S and Jamieson I G 1995 New approaches toward a better understanding of the decline of Takahe (Porphyrio mantelli) in New Zealand;Conserv. Biol. 9 100–106CrossRefGoogle Scholar
  20. Burbidge A A and McKenzie N L 1989 Patterns in the modern decline of western Australia’s vertebrate fauna: causes and conservation implications;Biol. Conserv. 50 143–198CrossRefGoogle Scholar
  21. Burgman M A, AkÇakaya H R. and Loew S S 1988 The use of extinction models for species conservation;Biol. Conserv. 43 9–25CrossRefGoogle Scholar
  22. Burgman M A, Cantoni D and Vogel P 1992 Shrews in suburbia: an application of Goodman’s extinction model;Biol. Conserv. 61 117–123CrossRefGoogle Scholar
  23. Burgman M A, Ferson A and AkÇakaya H R 1993Risk assessment in conservation biology (London: Chapman and Hall)Google Scholar
  24. Burgman M A, Keith D A, Rohlf F J and Todd C R 1999 Probabilistic classification rules for setting conservation priorities;Biol. Conserv. 89 227–231CrossRefGoogle Scholar
  25. Burkey T V 1995 Faunal collapse in East African game reserves revisited;Biol. Conserv. 71 107–110CrossRefGoogle Scholar
  26. Burton J A 1984 A bibliography of red data books;Oryx 18 61–64CrossRefGoogle Scholar
  27. Caughley G 1994 Directions in conservation biology;J. Anim. Ecol. 63 215–244CrossRefGoogle Scholar
  28. Chapman J A and Flux J E C (and the IUCN/SSC Lagomorph Specialist Group) 1990Rabbits, Hares and Pikas. Status survey and conservation action plan (Gland, Switzerland: IUCN)Google Scholar
  29. Chatelain C, Gautier L and Spichiger R 1996 A recent history of forest fragmentation in southwestern Ivory Coast;Biodiver. Conserv. 5 37–53CrossRefGoogle Scholar
  30. Clark T W, Backhouse G N and Lacy R C 1991 Report of a workshop on population viability assessment as a tool for threatened species management and conservation;Aust. Zool. 27 28–35Google Scholar
  31. Collar N J, Crosby M J and Stattersfield A J 1994Birds to watch 2: the world list of threatened birds (Cambridge: Bird Life International)Google Scholar
  32. Collar N J and Stuart S N 1985Threatened birds of Africa and Related Islands: the ICBP/IUCN Red Data book, Part 1 (Cambridge: ICBP and IUCN)Google Scholar
  33. Colyvan M, Burgman M A, Todd C R, AkÇakaya H R and Boek C 1999 The treatment of uncertainty and the structure of the IUCN threatened species categories;Biol. Conserv. 89 245–249CrossRefGoogle Scholar
  34. Crooks K R and Soulé M E 1999 Mesopredator release and avifaunal extinctions in a fragmented system;Nature (London)400 563–566CrossRefGoogle Scholar
  35. Davies K I and Margules C R 1998 Effects of habitat fragmentation on carabid beetles: experimental evidence;J. Anim. Ecol. 67 460–471CrossRefGoogle Scholar
  36. Davies K I, Margules C R and Lawrence J F 2000 Which traits of species predict population declines in experimental forest fragments?;Ecology 81 1450–1461Google Scholar
  37. Dean W R J 1997 The distribution and ecology of nomadic birds in the Karoo, South Africa;J. Biogeogr. 24 769–779CrossRefGoogle Scholar
  38. Dempster J P 1991 Fragmentation, isolation and mobility of insect populations; inThe conservation of insects and their habitats (eds) N M Collins and J A Thomas (London: Academic Press) pp 143–153Google Scholar
  39. Dennis B, Munholland P L and Scott J M 1991 Estimation of growth and extinction parameters for endangered species;Ecol. Monogr. 6 115–143CrossRefGoogle Scholar
  40. Dennis R L H 1993Butterflies and climate change (Manchester: Manchester University Press)Google Scholar
  41. Dennis R L H and Shreeve T G 1991 Climatic change and the British butterfly fauna: opportunities and constraints;Biol. Conserv. 55 1–16CrossRefGoogle Scholar
  42. Diamond J M 1975a The island dilemma: lessons of modern biogeographic studies for the design of natural reserves;Biol. Conserv. 7 129–146CrossRefGoogle Scholar
  43. Diamond J M 1975b Assembly of species communities; inEcology and evolution of communities (eds) M L Cody and J M Diamond (Cambridge, Mass.: Harvard University Press pp 342–444Google Scholar
  44. Dias P 1996 Sources and sinks in population biology;Trends Ecol. Evol. 11 326–330CrossRefGoogle Scholar
  45. Dickman C R, Pressey R L, Lim L and Parnaby H E 1993 Mammals of particular conservation concern in the Western Division of New South Wales;Biol. Conserv. 65 219–248CrossRefGoogle Scholar
  46. Dinerstein E and Wikramanayake E D 1993 Beyond "hotspots": how to prioritize investments to conserve biodiversity in the Indo-Pacific region;Conserv. Biol. 7 53–65CrossRefGoogle Scholar
  47. Doak D F and Mills L S 1994 A useful role for theory in conservation;Ecology 75 615–626CrossRefGoogle Scholar
  48. Downton M W 1995 Measuring tropical deforestation: development of the methods;Environ. Conserv. 22 229–240Google Scholar
  49. Durant S M and Mace G M 1994 Species differences and population structure in population viability analysis; inCreative conservation: Interactive management of wild and captive animals (eds) P J S Olney, G M Mace and A T C Feistner (London: Chapman and Hall) pp 67–91Google Scholar
  50. East R (ed.) 1988a Summary of regional status of antelopes in east and northeast Africa; inAntelopes: Global survey and regional action plans: Part 1. East and northeast Africa (Gland, Switzerland: IUCN) pp 71–76Google Scholar
  51. East R (ed.) 1988b Antelopes:Global survey and regional action plans: Part 1. East and northeast Africa (Gland, Switzerland: IUCN)Google Scholar
  52. East R (ed.) 1989a Summary of regional status of antelopes in southern and south-central Africa; inAntelopes: Global survey and regional action plans: Part 2. Southern and south-central Africa (Gland, Switzerland: IUCN) pp 76–79Google Scholar
  53. East R (ed.) 1989bAntelopes: Global survey and regional action plans: Part 2. Southern and south-central Africa (Gland, Switzerland: IUCN)Google Scholar
  54. East R (ed.) 1990a Summary of regional status of antelopes in west and central Africa; inAntelopes: Global survey and regional action plans: Part 3. West and central Africa (Gland, Switzerland: IUCN) pp 139–143Google Scholar
  55. East R (ed.) 1990bAntelopes: Global survey and regional action plans: Part 3. West and central Africa (Gland, Switzerland: IUCN)Google Scholar
  56. Faith D P, Margules C R and Walker P A 2001 A biodiversity conservation plan for Papua New Guinea based on biodiversity trade-offs analysis;Pac. Conserv. Biol. 6 304–324Google Scholar
  57. Faith D P and Walker P A 1996 Integrating conservation and development: effective trade-offs between biodiversity and cost in the selection of protected areas;Biodiver. Conserv. 5 431–446CrossRefGoogle Scholar
  58. Fearnside P M 1990 The rate and extent of deforestation in Brazilian Amazonia;Environ. Conserv. 17 213–226Google Scholar
  59. Foley P 1994 Predicting extinction times from environmental stochasticity and carrying capacity;Conserv. Biol. 8 124–137CrossRefGoogle Scholar
  60. Forman R T T 1995Land mosaics: the ecology of landscapes and regions (Cambridge: Cambridge University Press)Google Scholar
  61. Forman R T T and Godron M 1986Landscape ecology (New York: Wiley)Google Scholar
  62. Foster-Turley P, Macdonald S and Mason C (and the IUCN/ SSC Otter Specialist Group) 1990Otters. An action plan for their conservation (Gland, Switzerland: IUCN)Google Scholar
  63. Francis I S, Penford N, Gartshore M E and Jaramillo A 1992 The White-breasted GuineafowlAgelastes meleagrides in TaÏ National Park (CÔte d’Ivoire);Bird Conserv. Int. 2 25–60CrossRefGoogle Scholar
  64. Franklin I R 1980 Evolutionary change in small populations; inConservation biology: An evolutionary-ecological perspective (eds) M E Soulé and B A Wilcox (Sunderland, Mass: Sinauer) pp 135–149Google Scholar
  65. Freitag S and van Jaarsveld A S 1997 Relative occupancy, endemism, taxonomic distinctiveness and vulnerability: prioritizing regional conservation actions;Biodiver. Conserv. 6 211–232CrossRefGoogle Scholar
  66. Frissell C A 1993 Topology of extinction and endangerment of native fishes in the Pacific Northwest and California (USA);Conserv. Biol. 7 342–354CrossRefGoogle Scholar
  67. Gaston K J 1994Rarity (London: Chapman and Hall)Google Scholar
  68. Gaston K J 1996 The multiple forms of the interspecific abundance-distribution relationship;Oikos 75 211–220CrossRefGoogle Scholar
  69. Gaston K J 1999 Implications of interspecific and intraspecific abundance-occupancy relationships;Oikos 86 195–207CrossRefGoogle Scholar
  70. Gaston K J, Blackburn T M, Greenwood J J D, Gregory R D, Quinn R M and Lawton J H 2000 Abundance-occupancy relationships;J. Appl. Ecol. (Suppl. 1)37 39–59CrossRefGoogle Scholar
  71. Gaston K J, Blackburn T M and Lawton J H 1997 Interspecific abundance-range size relationships: an appraisal of mechanisms;J. Anim. Ecol. 66 579–601CrossRefGoogle Scholar
  72. Gaston K J and Lawton J H 1990 Effects of scale and habitat on the relationship between regional distribution and local abundance;Oikos 58 329–335CrossRefGoogle Scholar
  73. Gaston K J and McArdle B H 1993 All else is not equal: temporal population variability and insect conservation; inPerspectives on insect conservation (eds) K J Gaston, T R New and M E Samways (Andover: Intercept) pp 171–184Google Scholar
  74. Gaston K J and McArdle B H 1994 The temporal variability of animal abundances: measures, methods and patterns;Philos. Trans. R. Soc. London B345 335–358Google Scholar
  75. Gaston K J and Nicholls A O 1995 Probable times to extinction of some rare breeding bird species in the United Kingdom;Proc. R. Soc. London B259 119–123CrossRefGoogle Scholar
  76. Gilpin M E and Hanski I (eds) 1991Metapopulation dynamics (London: Academic Press)Google Scholar
  77. Ginsberg J R and Macdonald D W (and the IUCN/SSC Canid and Wolf Specialist Groups) 1990Foxes, wolves, jackals, and dogs. An action plan for the conservation of canids (Gland, Switzerland: IUCN)Google Scholar
  78. Given D R and Norton D A 1993 A multivariate approach to assessing threat and for priority setting in threatened species conservation;Biol. Conserv. 64 57–66CrossRefGoogle Scholar
  79. Gray R D and Craig J L 1991 Theory really matters: hidden assumptions in the concept of "habitat requirements";Acta XX Congressus Internationalis Ornithologici 2553–2560Google Scholar
  80. Haila Y 1986 On the semiotic dimension of ecological theory: the case of island biogeography;Biol. Philos. 1 377–387CrossRefGoogle Scholar
  81. Hall A V and Veldhuis H A 1985 South African Red Data Book, plants —fynbos and karoo biomes;S. Afr. Natl. Sci. Prog. Rep. 117 1–160Google Scholar
  82. Hannah L, Lohse D, Hutchinson C, Carr J L and Lankerani A 1994 A preliminary inventory of human disturbance of world ecosystems;Ambio 23 246–250Google Scholar
  83. Hanski I 1982 Dynamics of regional distribution: the core and satellite hypothesis;Oikos 38 210–221CrossRefGoogle Scholar
  84. Hanski I 1991 Single-species metapopulation dynamics: concepts, models and observations;Biol. J. Linn. Soc. 42 17–38Google Scholar
  85. Hanski I 1992 Inferences from ecological incidence functions;Am. Nat. 139 657–662CrossRefGoogle Scholar
  86. Hanski I and Woiwood I P 1993 Spatial synchrony in the dynamics of moth and aphid populations;J. Anim. Ecol. 62 656–668CrossRefGoogle Scholar
  87. Hargis C D, Bissonette J A and David J L 1998 The behaviour of landscape metrics commonly used in the study of habitat fragmentation;Landscape Ecol. 13 167–186CrossRefGoogle Scholar
  88. Harrison S 1991 Local extinction in a metapopulation context: an empirical evaluation;Biol. J. Linn. Soc. 42 73–88Google Scholar
  89. Harrison S 1994 Metapopulations and conservation; inLarge-scale ecology and conservation biology (eds) P J Edwards, R M May and N R Webb (Oxford: Blackwell Scientific) pp 111–128Google Scholar
  90. Harrison S and Bruna E 1999 Habitat fragmentation and large-scale conservation: what do we know for sure?;Ecography 22 225–232CrossRefGoogle Scholar
  91. Harrison S and Quinn J F 1989 Correlated environments and the persistence of metapopulations;Oikos 56 193–198CrossRefGoogle Scholar
  92. Houghton R A 1994 The worldwide extent of land-use change;BioScience 44 305–313CrossRefGoogle Scholar
  93. Howe R W, Davis G J and Mosca V 1991 The demographic significance of ’sink’ populations;Biol. Conserv. 57 239–255CrossRefGoogle Scholar
  94. Hunter M L Jr and Hutchinson A 1994 The virtues and shortcomings of parochialism: conserving species that are locally rare, but globally common;Conserv. Biol. 8 1163–1165CrossRefGoogle Scholar
  95. IUCN (The World Conservation Union) 1994aIUCN Red List Categories (Gland, Switzerland: IUCN)Google Scholar
  96. IUCN (The World Conservation Union) 1994bGuidelines for protected area management categories (Gland, Switzerland: IUCN)Google Scholar
  97. Iversen L R and Prasad A M 1998 Predicting abundance of 80 tree species following climate change in the eastern United States;Ecol. Monogr. 68 465–485CrossRefGoogle Scholar
  98. Jarman M L (ed.) 1986 Conservation priorities in lowland regions of the fynbos biome;S. Afr. Natl. Sci. Progr. Rep. 87 1–55Google Scholar
  99. Jarvis A M and Robertson A 1999 Predicting population sizes and priority conservation areas for 10 endemic Namibian bird species;Biol. Conserv. 88 121–131CrossRefGoogle Scholar
  100. Keith D A 1998 An evaluation and modification of World Conservation Union Red List criteria for classification of extinction risk in vascular plants;Conserv. Biol. 12 1076–1090CrossRefGoogle Scholar
  101. Kershaw M, Mace G M and Williams P H 1995 Threatened status, rarity, and diversity as alternative selection measures for protected areas: a test using Afrotropical antelopes;Conserv. Biol. 9 324–334CrossRefGoogle Scholar
  102. Kienast F 1993 Analysis of historic landscape patterns with a Geographic Information System —a methodological outline;Landscape Ecol. 8 103–118CrossRefGoogle Scholar
  103. Kirkpatrick J B and Brown M J 1991a Planning for species conservation; inNature conservation: Cost effective biological surveys and data analysis (eds) C R Margules and M P Austin (Melbourne: CSIRO) pp 83–89Google Scholar
  104. Kirkpatrick J B and Brown M J 1991bReservation analysis of Tasmanian forests (Canberra: Resource Assessment Commission)Google Scholar
  105. Kupfer J A 1995 Landscape ecology and biogeography;Prog. Phys. Geogr. 19 18–34Google Scholar
  106. Lacy R C 1993 VORTEX: a computer simulation model for population viability analysis;Wildl. Res. 20 45–65CrossRefGoogle Scholar
  107. Lahti T, Kemppainen E, Kurtto A and Uotila P 1991 Distribution and biological characteristics of threatened vascular plants in Finland;Biol. Conserv. 55 299–314CrossRefGoogle Scholar
  108. Lambeck R J 1997 Focal species: a multi-species umbrella for nature conservation;Conserv. Biol. 11 849–856CrossRefGoogle Scholar
  109. Laurance W F 1998 A crisis in the making: responses of Amazonian forests to land use and climate change;Trends Ecol. Evol. 13 411–415CrossRefGoogle Scholar
  110. Lawton J H 1994 Population dynamic principles;Philos. Trans. R. Soc. London B344 61–68Google Scholar
  111. Leemans R 1996 Biodiversity and global change; inBiodiversity: a biology of numbers and difference (ed.) K J Gaston (Oxford: Blackwell Science) pp 367–387Google Scholar
  112. Lindenmayer D B 1996Wildlife and woodchips: Leadbeater’s possum as a test case of ecologically sustainable forestry (Sydney: New South Wales University Press, Australian Natural History Series)Google Scholar
  113. Lindenmayer D B and Lacy R C 1995 Metapopulation viability of arboreal marsupials in fragmented old growth forests: a comparison among species;Ecol. Appl. 5 183–199CrossRefGoogle Scholar
  114. Lindenmayer D B, Lacy R C, Thomas V C and Clark T W 1993 Predictions of the impacts of changes in population size and environmental variability on Leadbeater’s Possum,Gymnobelideus leadbeateri McCoy (Marsupalia: Petauridae) using population viability analysis: an application of the computer program VORTEX;Wildl. Res. 20 67–86Google Scholar
  115. Lindenmayer D B, Nix H A, McMahon J P, Hutchinson M F and Tanton M T 1991 The conservation of Leadbeater’s Possum,Gymnobelideus leadbeateri (McCoy): a case study of the use of bioclimatic modelling;J. Biogeogr. 18 371–383CrossRefGoogle Scholar
  116. Lindenmayer D B, Margules C R and Botkin D B 2000 Indicators of biodiversity for ecologically sustainable forest management;Conserv. Biol. 14 941–950CrossRefGoogle Scholar
  117. Lindenmayer D B and Possingham P H 1996 Applications of population viability analysis in conservation biology in Australia; inSpecies survival in fragmented landscapes (eds) J Settele, C Margules, P Poschlod and K Henle (Dordrecht: Kluwer Academic Publishers) pp 102–110Google Scholar
  118. Lindenmayer D B, Ritman K R, Cunningham R B, Smith J and Howarth D 1995 Predicting the spatial distribution of the greater glider,Petauroides volans KERR, in a timber production forest block in south-eastern Australia;Wildl. Res. 22 445–456CrossRefGoogle Scholar
  119. Lloyd J W, Tellam J H, Rukin N and Lerner D N 1993 Wetland vulnerability in East Anglia: a possible conceptual framework and generalized approach;J. Environ. Manag. 37 87–102CrossRefGoogle Scholar
  120. Lombard A T 1995 The problems with multi-species conservation: do hotspots, ideal reserves and existing reserves coincide?;S. Afr. J. Zool. 30 145–163Google Scholar
  121. MacArthur R H and Wilson E O 1963 An equilibrium theory of insular zoogeography;Evolution 17 373–387CrossRefGoogle Scholar
  122. MacArthur R H and Wilson E O 1967The theory of island biogeography (Princeton, New Jersey: Princeton University Press)Google Scholar
  123. Mace G M 1994a The status of proposals to redefine the IUCN threatened species categories; inIUCN red list of threatened animals (ed.) B Groombridge (Gland, Switzerland: IUCN) pp xlviii-lvGoogle Scholar
  124. Mace G M 1994b An investigation into methods for categorising the conservation status of species; inLarge-scale ecology and conservation biology (eds) P J Edwards, R M May and N R Webb (Oxford: Blackwell Scientific) pp 293–312Google Scholar
  125. Mace G M 1994c Classifying threatened species: means and ends;Philos. Trans. R. Soc. London B344 91–97Google Scholar
  126. Mace G M and Collar N J 1994 Extinction risk assessment for birds through quantitative criteria;Ibis 137 S240-S246Google Scholar
  127. Mace G, Collar N, Cooke J, Gaston K, Ginsberg J, Leader-Williams N, Maunder M and Milner-Gulland E J 1992 The development of new criteria for listing species on the IUCN Red list;Species 19 16–22Google Scholar
  128. Mace G M and Lande R 1991 Assessing extinction threats: toward a reevaluation of IUCN threatened species categories;Conserv. Biol. 5 148–157CrossRefGoogle Scholar
  129. Mace G M and Stuart S N 1994 Draft IUCN Red List Categories, Version 2.2;Species 21–22 13–24Google Scholar
  130. Mangel M and Tier C 1994 Four facts every conservation biologist should know about persistence;Ecology 75 607–614CrossRefGoogle Scholar
  131. Margules C R 1989 Selecting nature reserves in South Australia; inMediterranean landscapes in Australia: Mallee ecosystems and their management (eds) J C Noble and R A Bradstock (Melbourne: CSIRO) pp 398–405Google Scholar
  132. Margules C R, Davies K F, Meyers J A and Milkovits G A 1995 The responses of some selected arthropods and the frog,Crinia signifera to habitat fragmentation; inConserving biodiversity: Threats and solutions (eds) R A Bradstock, T D Auld, D A Keith, R T Kingsford, D Lunney and D P Sivertsen (Sydney: Surrey Beatty) pp 94–103Google Scholar
  133. Margules C R, Higgs A J and Rafe R W 1982 Modern biogeographic theory: are there any lessons for nature conservation?;Biol. Conserv. 24 115–128CrossRefGoogle Scholar
  134. Margules C R, Milkovits G A and Smith G T 1994a Contrasting effects of habitat fragmentation on the scorpionCercophonius squama and an amphipod;Ecology 75 2033–2042CrossRefGoogle Scholar
  135. Margules C R, Nicholls A O and Pressey R L 1988 Selecting networks of reserves to maximize biological diversity;Biol. Conserv. 46 63–76CrossRefGoogle Scholar
  136. Margules C R, Nicholls A O and Usher M B 1994b Apparent species turnover, probability of extinction and the selection of nature reserves: a case study of the Ingleborough limestone pavements;Conserv. Biol. 8 398–409CrossRefGoogle Scholar
  137. Margules C R and Pressey R L 2000 Systematic conservation planning;Nature (London)405 243–253CrossRefGoogle Scholar
  138. Margules C R, Pressey R L and Williams P H 2002 Representing biodiversity: data and procedures for identifying priority areas of conservation;J. Biosci. (Suppl. 2)27 309–326PubMedGoogle Scholar
  139. Margules C R and Stein J L 1989 Patterns in the distributions of species and the selection of nature reserves: an example from Eucalyptus forests in south-eastern New South Wales;Biol. Conserv. 50 219–238CrossRefGoogle Scholar
  140. McIntyre S 1992 Risks associated with the setting of conservation priorities from rare plant species lists;Biol. Conserv. 60 31–37CrossRefGoogle Scholar
  141. McIntyre S and Barrett G W 1992 Habitat variegation, an alternative to fragmentation;Conserv. Biol. 6 146–147CrossRefGoogle Scholar
  142. Menge E S 1990 Population viability analysis for an endangered plant;Conserv. Biol. 4 52–62CrossRefGoogle Scholar
  143. Menon S and Bawa K S 1998 Deforestation in the tropics: reconciling disparities in estimates for India;Ambio 27 576–577Google Scholar
  144. Miller K R 1996Balancing the scales: guidelines for increasing biodiversity’s chances through bioregional management (Washington DC: World Resources Institute)Google Scholar
  145. Millsap B A, Gore J A, Runde D E and Cerulean S I 1990 Setting priorities for the conservation of fish and wildlife species in Florida;Wildl. Monogr. 111 1–57Google Scholar
  146. Mittermeier R A, Myers N, Thomsen J B, da Fonseca GAB and Olivieri S 1998 Biodiversity hotspots and major tropical wilderness areas: approaches to setting conservation priorities;Conserv. Biol. 12 516–520CrossRefGoogle Scholar
  147. Molloy J and Davis A 1992Setting priorities for the conservation of New Zealand’s threatened plants and animals (Wellington: Department of Conservation)Google Scholar
  148. Morton S R 1990 The impact of European settlement on the vertebrate animals of arid Australia: a conceptual model;Proc. Ecol. Soc. Aust. 16 201–213Google Scholar
  149. Morton S R, Smith D M S, Friedel M H, Griffin G F and Pickup G 1995a The stewardship of arid Australia: ecology and landscape management;J. Environ. Manag. 43 195–217CrossRefGoogle Scholar
  150. Morton S R, Short J, Barker R D, Griffin G F and Pearce G 1995b Refugia for Biological Diversity in Arid and Semi-arid Australia; inBiodiversity Series Paper No. 4 (Canberra: Department of the Environment, Sport and Territories)Google Scholar
  151. Mouat D and Steinitz C 1997 Biodiversity and landscape planning: alternative futures for the region of Camp Pendleton, California —management implications for park boundaries; inNational parks and protected areas: Selection, delimitation and management (eds) J J Pigram and R C Sundell (Armidale: University of New England) pp 297–314Google Scholar
  152. Munton P 1987 Concepts of threat to the survival of species used in Red Data Books and similar compilations; inThe road to extinction: Problems with categorizing the status of taxa threatened with extinction (eds) R Fitter and M Fitter (Gland, Switzerland: IUCN) pp 71–111Google Scholar
  153. Myers N 1979The sinking ark: a new look at the problem of disappearing species (oxford: Pergamon Press)Google Scholar
  154. Myers N 1988 Threatened biotas: "hot spots" in tropical forests;Environmentalist 8 187–208PubMedCrossRefGoogle Scholar
  155. Myers N 1990 The biodiversity challenge: expanded hot-spots analysis;Environmentalist 10 243–256PubMedCrossRefGoogle Scholar
  156. Myers N 1993 Tropical forests: the main deforestation fronts;Environ. Conserv. 20 9–16CrossRefGoogle Scholar
  157. Myers N, Mittermeier R A, Mittermeier C G, Da Fonseca GAB and Kent J 2000 Biodiversity hotspots for conservation priorities;Nature (London)403 853–858CrossRefGoogle Scholar
  158. Nepstad D C, Verissimo A, Alencar A, Nobre C, Lima E, Lefebvre P, Schlesinger P, Potter C, Moutinho P, Mendoza E, Cochrane M and Brooks V 1999 Large-scale impoverishment of Amazonian forests by logging and fire;Nature (London)398 505–508CrossRefGoogle Scholar
  159. New T R and Collins N M (and the IUCN/SSC Lepidoptera Specialist Group) 1991Swallowtail butterflies. An action plan for their conservation (Gland, Switzerland: IUCN)Google Scholar
  160. Newmark W D 1985 Legal and biotic boundaries of western North American national parks: a problem of congruence;Biol. Conserv. 33 197–208CrossRefGoogle Scholar
  161. Newmark W D 1987 A land-bridge island perspective on mammalian extinctions in western North American parks;Nature (London)325 430–432CrossRefGoogle Scholar
  162. Newmark W D 1993 The role and design of wildlife corridors with examples from Tanzania;Ambio 22 500–504Google Scholar
  163. Nicoll M E Rathbun G B (and the IUCN/SSC Insectivore, Treeshrew and Elephant-shrew Specialist Group) 1990African insectivora and elephant-shrews. An action plan for their conservation (Gland, Switzerland: IUCN)Google Scholar
  164. Nicholls A O 1989 How to make biological surveys go further with generalised linear models;Biol. Conserv. 50 51–75CrossRefGoogle Scholar
  165. Nicholls A O 1998 Integrating population abundance, dynamics and distribution into broad-scale priority setting; inConservation in a changing world: Integrating processes into priorities for action (eds) G M Mace, A Balmford and J R Ginsberg (Cambridge: Cambridge University Press) pp 251–272Google Scholar
  166. Nicholls A O and Margules C R 1991 The design of studies to demonstrate the biological importance of corridors; inNature conservation 2: the role of corridors (eds) D A Saunders and R J Hobbs (Sydney: Surrey Beatty) pp 49–61Google Scholar
  167. Nicholls A O and Margules C R 1993 An upgraded reserve selection algorithm;Biol. Conserv. 64 165–169CrossRefGoogle Scholar
  168. Nix H A 1976 Environmental control of breeding, post-breeding dispersal and migration of birds in the Australian region; inProceedings of the 16th Ornithological Congress, Canberra 1974 (eds) H J Frith and J H Calaby (Canberra: Australian Academy of Science) pp 272–305Google Scholar
  169. Nix H A 1982 Environmental determinants of biogeography and evolution in Terra Australis; inEvolution of the flora and fauna of arid Australia (eds) W R Baker and P J M Greenslade (South Australia: Peacock Publishers) pp 47–56Google Scholar
  170. Noss R F 1987 Corridors in real landscapes: a reply to Simberloff and Cox;Conserv. Biol. 1 159–164CrossRefGoogle Scholar
  171. Noss R F and Harris L D 1986 Nodes, networks and MUMs: preserving species at all scales;Environ. Manag. 10 299–309CrossRefGoogle Scholar
  172. Olson D M and Dinerstein E 1998 The global 200: a representation approach to conserving the Earth’s most biologically valuable ecoregions;Conserv. Biol. 12 502–515CrossRefGoogle Scholar
  173. Owen-Smith N 1989 Megafaunal extinctions: the conservation message from 11,000 years B.P.;Conserv. Biol. 3 405–412CrossRefGoogle Scholar
  174. Perring F H and Farrell L 1983British red data books I. Vascular plants 2nd edition (Lincoln: Royal Society for Nature Conservation)Google Scholar
  175. Peters R L and Darling J D S 1985 The greenhouse effect and nature reserves;BioScience 35 707–717CrossRefGoogle Scholar
  176. Peters R L and Lovejoy T E (eds) 1992Global warming and biological diversity (New Haven: Yale University Press)Google Scholar
  177. Pickett S T A and Thompson J N 1978 Patch dynamics and the design of nature reserves;Biol. Conserv. 13 27–37CrossRefGoogle Scholar
  178. Pimm S L 1991The balance of nature?: Ecological issues in the conservation of species and communities (Chicago: University of Chicago Press)Google Scholar
  179. Pimm S L, Jones H L and Diamond J 1988 On the risk of extinction;Am. Nat. 132 757–785CrossRefGoogle Scholar
  180. Pollard E 1991 Synchrony of population fluctuations: the dominant influence of widespread factors on local butterfly populations;Oikos 60 7–10CrossRefGoogle Scholar
  181. Pollard E and Yates T J 1993Monitoring butterflies for ecology and conservation (London: Chapman and Hall)Google Scholar
  182. Possingham H P 1996 Risk and uncertainty: mathematical models and decision-making in conservation biology; inConservation biology (ed.) I F Spellerberg (Harlow: Longman) pp 222–234Google Scholar
  183. Possingham H P, Davies I, Noble I R and Norton T W 1992 A metapopulation simulation model for assessing the likelihood of plant and animal extinctions;Math. Comput. Simulation 33 367–372CrossRefGoogle Scholar
  184. Possingham H P, Lindenmayer D B and Norton T W 1993 A framework for the improved management of threatened species based on Population Viability Analysis (PVA);Pacific conserv. Biol. 1 39–45Google Scholar
  185. Pressey R L 1996 Protected areas: where should they be and why should they be there?; inConservation biology (ed.) I F Spellerberg (Harlow: Longman) pp 171–185Google Scholar
  186. Pressey R L 1998 Algorithms, politics and timber: an example of the role of science in a public, political negotiation process over new conservation areas in production forests; inEcology for everyone: Communicating ecology to scientists, the public and the politicians (eds) R Willis and R Hobbs (Sydney: Surrey Beatty) pp 73–87Google Scholar
  187. Pressey R L and Cowling R M 2001 Reserve selection algorithms and the real world;Conserv. Biol. 15 275–277CrossRefGoogle Scholar
  188. Pressey R L, Ferrier S, Hager T C, Woods C A, Tully S L and Weinman K M 1996 How well protected are the forests of north-eastern New South Wales? —Analyses of forest environments in relation to tenure, formal protection measures and vulnerability to clearing;For. Ecol. Manag. 85 311–333CrossRefGoogle Scholar
  189. Pressey R L and Griffith S J 1992 Vegetation of the coastal lowlands of Tweed Shire, northern New South Wales: plant associations, species and conservation;Proc. Linn. Soc. N. S. W. 113 203–243Google Scholar
  190. Pressey R L, Hager T C, Ryan K M, Schwarz J, Wall S, Ferrier S and Creaser P M 2000 Using abiotic data for conservation assessments over extensive regions: quantitative methods applied across New South Wales;Biol. Conser. 96 55–82CrossRefGoogle Scholar
  191. Pressey R L, Humphries C J, Margules C R, Vane-Wright R I and Williams P H 1993 Beyond opportunism: key principles for systematic reserve selection;Trends Ecol. Evol. 8 124–128CrossRefGoogle Scholar
  192. Pressey R L and Logan V S 1995 Reserve coverage and requirements in relation to partitioning and generalization of land classes: analyses for western New South Wales;Conserv. Biol. 9 1506–1517CrossRefGoogle Scholar
  193. Pressey R L and Logan V S 1998 Size of selection units for future reserves and its influence on actual vs targeted representation of features: a case study in western New South Wales;Biol. Conserv. 85 305–319CrossRefGoogle Scholar
  194. Pressey R L and Nicholls A O 1989 Efficiency in conservation evaluation: scoring vs iterative approaches;Biol. Conserv. 50 199–218CrossRefGoogle Scholar
  195. Pulliam H R 1988 Sources, sinks, and population regulation;Am. Nat. 132 652–661CrossRefGoogle Scholar
  196. RACAC (Resource and Conservation Assessment Council) 1996Draft Interim Forestry Assessment Report (Sydney: RACAC)Google Scholar
  197. Rebelo A G 1992 Red Data book species in the Cape Floristic Region: threats, priorities and target species;Trans. R. Soc. S. Afr. 48 55–86Google Scholar
  198. Rebelo A G and Tansley S A 1993 Using rare plant species to identify priority conservation areas in the Cape Floristic Region: the need to standardise for total species richness;S. Afr. J. Sci. 89 156–161Google Scholar
  199. Redford K H and Robinson J G 1991 Park size and the conservation of forest mammals in Latin America; inLatin American mammalogy: history, biodiversity, and conservation (eds) M A Mares and D J Schmidly (Norman: University of Oklahoma Press) pp 227–234Google Scholar
  200. Reed J M 1992 A system for ranking conservation priorities for Neotropical migrant birds based on relative susceptibility to extinction; inEcology and conservation of neotropical migrant landbirds (eds) J M Hagan III and D W Johnston (Washington DC: Smithsonian Institution Press) pp 524–536Google Scholar
  201. Robinson G R, Holt R D, Gaines M S, Hamburg S P, Johnson M L, Fitch H S and Martinko E A 1992 Diverse and contrasting effects of habitat fragmentation;Science 257 524–526PubMedCrossRefGoogle Scholar
  202. Rodrigues A S L, Gregory R D and Gaston K J 2000 Robustness of reserve selection procedures under temporal species turnover;Proc. R. Soc. London B267 49–55CrossRefGoogle Scholar
  203. Rudel T and Roper J 1996 Regional patterns and historical trends in tropical deforestation, 1976–1990: a qualitative comparative analysis;Ambio 25 160–166Google Scholar
  204. Sarkar S and Margules C 2002 Operationalizing biodiversity for conservation planning;J. Biosci. (Suppl. 2)27 299–308PubMedGoogle Scholar
  205. Sauer J 1969 Oceanic islands and biogeographic theory;Geogr. Rev. 59 582–593CrossRefGoogle Scholar
  206. Saunders D A and Hobbs R J (eds) 1991Nature conservation 2: The role of corridors (Sydney: Surrey Beatty)Google Scholar
  207. Saunders D A, Hobbs R J and Margules C R 1991 Biological consequences of ecosystem fragmentation: a review;Conserv. Biol. 5 18–32CrossRefGoogle Scholar
  208. Schoener T W and Spiller D A 1992 Is extinction rate related to temporal variability in population size? An empirical answer for orb spiders;Am. Nat. 139 1176–1207CrossRefGoogle Scholar
  209. Scholtz C H and Chown S L 1993 Insect conservation and extensive agriculture: the savannah of southern Africa; inPerspectives on insect conservation (eds) K J Gaston, T R New and M J Samways (Andover: Intercept) pp 75–95Google Scholar
  210. Schwartz M W 1999 Choosing the appropriate scale of reserves for conservation;Annu. Rev. Ecol. Syst. 30 83–108CrossRefGoogle Scholar
  211. Scott J M, Csuti B, Jacobi J D and Estes J E 1987 Species richness: a geographic approach to protecting future biological diversity;BioScience 37 782–788CrossRefGoogle Scholar
  212. Scott J M, Davis F, Csuti B, Noss R, Butterfield B, Groves C, Anderson H, Caicco S, D’Erchia F, Edwards T C, Ulliman J and Wright R G 1993 Gap analysis: a geographical approach to protection of biological diversity;Wildl. Monogr. 123 41Google Scholar
  213. Settele J, Margules C, Poschlod P and Henle K (eds) 1996Species survival in fragmented landscapes (Dordrecht: Kluwer Academic Publishers)Google Scholar
  214. Shrader-Frechette K S and McCoy ED 1993Method in ecology: Strategies for conservation (Cambridge: Cambridge University Press)Google Scholar
  215. Sieving K E and Karr J R 1997 Avian extinction and persistence mechanisms in lowland Panama; inTropical forest remnants: ecology, management, and conservation of fragmented communities (eds) W F Laurance and R O Bieregaard Jr (Chicago: University of Chicago Press) pp 156–170Google Scholar
  216. Simberloff D A 1988 The contribution of population and community biology to conservation science;Annu. Rev. Ecol. Syst. 19 473–511CrossRefGoogle Scholar
  217. Simberloff D S and Abele L G 1976 Island biogeography theory and conservation practice;Science 191 285–286PubMedCrossRefGoogle Scholar
  218. Simberloff D and Cox J 1987 Consequences and costs of conservation corridors;Conserv. Biol. 1 63–71CrossRefGoogle Scholar
  219. Sisk T D, Haddad N M and Ehrlich P R 1997 Bird assemblages in patchy woodlands: modelling the effects of edge and matrix habitats;Ecol. Appl. 7 1170–1180CrossRefGoogle Scholar
  220. Sisk T D, Launer A E, Switky K R and Ehrlich P R 1994 Identifying extinction threats: global analyses of the distribution of biodiversity and the expansion of the human enterprise;BioScience 44 592–604CrossRefGoogle Scholar
  221. Sisk T D and Margules C R 1993 Habitat edges and restoration: methods for quantifying edge effects and predicting the results of restoration efforts; inNature conservation 3: Reconstruction of fragmented ecosystems (eds) D A Saunders, R J Hobbs and P R Ehrlich (Sydney: Surrey Beatty) pp 57–68Google Scholar
  222. Sivertsen D 1994 The native vegetation crisis in the wheatbelt of New South Wales;Search 25 5–8Google Scholar
  223. Sivertsen D 1997 Assessment of native vegetation loss in the wheatbelt of NSW; inEcology at the cutting edge —Information technologies for managing biodiversity and ecological processes (eds) B Diekman, E Higginson, F Sutton and H Webb (Sydney: Nature Conservation Council of New South Wales) pp 84–97Google Scholar
  224. Sivertsen D and Metcalfe L 1995 Natural vegetation of the southern wheat-belt (Forbes and Cargelligo 1: 250,000 map sheets);Cunninghamia 4 103–128Google Scholar
  225. Soulé M E 1991 Conservation: tactics for a constant crisis;Science 253 744–750PubMedCrossRefGoogle Scholar
  226. Soulé M E, Wilcox B A and Holtby C 1979 Benign neglect: a model of faunal collapse in the game reserves of East Africa;Biol. Conserv. 15 259–272CrossRefGoogle Scholar
  227. Sprules D G 1991 Disturbance, equilibrium, and environmental variability: what is ’natural’ vegetation in a changing environment?;Biol. Conserv. 58 1–18CrossRefGoogle Scholar
  228. Taylor B 1991 Investigating species incidence over habitat fragments of different areas —a look at error estimation;Biol. J. Linn. Soc. 42 177–191Google Scholar
  229. Terborgh J 1986 Keystone plant resources in the tropical forest; inConservation Biology: the science of scarcity and diversity (ed.) M E Soulé (Sunderland, Mass.: Sinauer) pp 330–344Google Scholar
  230. Terborgh J 1988 The big things that run the world —A sequel to E O Wilson;Conserv. Biol. 2 402–403CrossRefGoogle Scholar
  231. Terborgh J 1992 Maintenance of diversity in tropical forests;Biotropica 24 283–292CrossRefGoogle Scholar
  232. Terborgh J 1999Requiem for nature (Washington DC: Island Press)Google Scholar
  233. Thomas J A 1991 Rare species conservation: case studies of European butterflies; inThe scientific management of temperate communities for conservation (eds) I F Spellerberg, F B Goldsmith and M G Morris (Oxford: Blackwell Scientific) pp 149–197Google Scholar
  234. Turner M G, O’Neill R V, Conley W, Conley M R and Humphries H C 1991 Pattern and scale: statistics for landscape ecology; inQuantitative methods in landscape ecology: the analysis and interpretation of landscape heterogeneity (eds) M G Turner and R H Gardner (New York: Springer-Verlag) pp 17–49Google Scholar
  235. Usher M B 1993 Primary succession on land: community development and wildlife conservation; inPrimary succession on land (eds) J Miles and D W H Walton (Oxford: Blackwell Scientific) pp 283–293Google Scholar
  236. VÄisÄnen R and Heliövaara K 1994 Hot-spots of insect diversity in northern Europe;Ann. Zool. Fenn. 31 71–81Google Scholar
  237. Vane-Wright R I 1996 Identifying priorities for the conservation of biodiversity: systematic biological criteria within a socio-political framework; inBiodiversity: a biology of numbers and difference (ed.) K J Gaston (Oxford: Blackwell Science) pp 309–344Google Scholar
  238. Veldkamp A and Fresco L O 1996 CLUE-CR: an integrated multi-scale model to simulate land use change scenarios in Costa Rica;Ecol. Model. 91 231–248CrossRefGoogle Scholar
  239. Virolainen K M, Virola T, Suhonen J, Kuitunen M, Lammin A and SiikamÄki P 1999 Selecting networks of nature reserves: methods do affect the long-term outcome;Proc. R. Soc. London B266 1141–1146CrossRefGoogle Scholar
  240. Ward D 1989 Monitoring community attrition;Biol. Conserv. 50 137–142CrossRefGoogle Scholar
  241. Watkinson A R and Sutherland W J 1995 Sources, sinks and pseudo-sinks;J. Anim. Ecol. 64 126–130CrossRefGoogle Scholar
  242. WCMC 1992Global biodiversity: Status of the Earth’s living resources (London: Chapman and Hall)Google Scholar
  243. White P S and Bratton S P 1980 After preservation: philosophical and practical problems of change;Biol. Conserv. 18 241–255CrossRefGoogle Scholar
  244. Whittaker R J 1998Island biogeography: ecology, evolution, and conservation (Oxford: Oxford University Press)Google Scholar
  245. Williams P H 1998 Key sites for conservation: area-selection methods for biodiversity; inConservation in a changing world: Integrating processes into priorities for action (eds) G M Mace, A Balmford and J R Ginsberg (Cambridge: Cambridge University Press) pp 211–249Google Scholar
  246. Williams P H, Gibbons D, Margules C, Rebelo A, Humphries C and Pressey R 1996 A comparison of richness hotspots, rarity hotspots and complementary areas for conserving diversity using British birds;Conserv. Biol. 10 155–174CrossRefGoogle Scholar
  247. Wilson E O and Willis E O 1975 Applied biogeography; inEcology and evolution of communities (eds) M L Cody and J M Diamond (Cambridge, Mass.: Harvard University Press) pp 522–534Google Scholar
  248. Witting L and Loeschcke V 1995 The optimization of biodiversity conservation;Biol. Conserv. 71 205–207CrossRefGoogle Scholar
  249. Woinarski J C Z 1993 Filling the lifeboats: endangered species first;Aust. Nat. Hist. 24 72Google Scholar
  250. Woinarski J C Z, Whitehead P J, Bowman D M J S and Russell-Smith J 1992 Conservation of mobile species in a variable environment: the problem of reserve design in the Northern Territory, Australia;Global Ecol. Biogeogr. Lett. 2 1–10CrossRefGoogle Scholar

Copyright information

© Indian Academy of Sciences 2002

Authors and Affiliations

  • K. J. Gaston
    • 1
  • R. L. Pressey
    • 1
    • 2
  • C. R. Margules
    • 1
    • 3
    Email author
  1. 1.Biodiversity and Macroecology Group, Department of Animal and Plant SciencesUniversity of SheffieldSheffieldUK
  2. 2.New South Wales National Parks and Wildlife ServiceArmidaleAustralia
  3. 3.CSIRO Sustainable EcosystemsTropical Forest Research Centre and the Rainforest Co-operative Research CentreAthertonAustralia

Personalised recommendations