Hostname: page-component-78c5997874-xbtfd Total loading time: 0 Render date: 2024-11-17T02:13:01.524Z Has data issue: false hasContentIssue false
  • English
  • Français

The consequences of habitat fragmentation for plant–pollinator mutualisms

Published online by Cambridge University Press:  28 February 2007

L. Fabienne Harris  and
Steven D. Johnson
Steven D. Johnson
Affiliation:
1School of Botany and Zoology, University of Natal, P. Bag X01, Scottsville, Pietermaritzburg, 3209, South Africa
Get access

Abstract

There is now considerable evidence for disruption of plant–pollinator mutualisms in fragmented landscapes. The causes can be myriad, and vary from lack of nesting sites for key insect pollinators, to a decline in pollinator visits when plant population sizes are reduced by fragmentation. One important and well-documented consequence of disruption in pollination systems is reduced seed production in plant populations in fragments as a result of pollen-limitation. When reduced seed production, in turn, has a negative effect on seedling recruitment, populations may enter a spiral towards extinction. Some pollination systems, on the other hand, are surprisingly resilient to anthropogenic changes, and pollen flow between trees in fragments separated by several kilometres has been reported recently. Understanding how reproductive attributes of plants, such as breeding systems and specificity of pollination systems, affect the outcome of habitat fragmentation remains a key challenge.

Keywords

Allee effectsbreeding systemextinctionhabitat fragmentationpollen flowpollen limitationpollinationpopulation size
Type
Review Article
Information
International Journal of Tropical Insect Science , Volume 24 , Issue 1 , March 2004 , pp. 29 - 43
Copyright
Copyright © ICIPE 2004

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Ågren, J. (1996) Population size, pollinator limitation, and seed set in the self-incompatible herb Lythrum salicaria. Ecology 77, 1779–1790.CrossRefGoogle Scholar
Aizen, M. A., Feinsinger, P. (1994a) Forest fragmentation, pollination, and plant reproduction in a Chaco dry forest, Argentina. Ecology 75, 330–351.CrossRefGoogle Scholar
Aizen, M. A., Feinsinger, P. (1994b) Habitat fragmentation, native insect pollinators, and feral honey bees in Argentine Chaco Serrano. Ecol. Appl. 4, 378–392.CrossRefGoogle Scholar
Aizen, M. A., Ashworth, L., Galetto, L. (2002) Reproductive success in fragmented habitats: do compatibility systems and pollination specialization matter?. J. Vegn. Sci. 13, 885–892.CrossRefGoogle Scholar
Allen-Wardell, G., Berhardt, P., Bitner, R., Burquez, A., Buchman, S., Cane, J., Cox, P. A., Dalton, V., Feinsinger, P., Ingram, M., Inouye, D., Jones, C. E., Kennedy, K., Kevan, P., Koopowitz, H., Medellin, R., Medellin-Morales, S., Nabhan, G. (1998) The potential consequences of pollinator declines on the conservation of biodiversity and stability of food crop yields. Conserv. Biol. 12, 8–17.Google Scholar
Anderson, G. J., Bernardello, G., Stuessy, T.F., Crawford, D.J. (2001) Breeding system and pollination of selected plants endemic to Juan Fernández Islands. Am. J. Bot. 88, 220–233.CrossRefGoogle ScholarPubMed
Arroyo, M. T. K. (1976) Geitonogamy in animal pollinated tropical angiosperms: a stimulus for the evolution of self-incompatibility. Taxon 25, 543–548.CrossRefGoogle Scholar
Barrett, S. C. H., Kohn, J. R. (1991) Genetic and evolutionary consequences of small population size in plants: implications for conservation pp .1–30Genetics and Conservation of Rare Plants, (edited byFalk, D. A., Holsinger, K. E.) Oxford University Press, New York, USA.Google Scholar
Bawa, K. S. (1974) Breeding systems of tree species of a lowland tropical community. Evolution 28, 85–92.CrossRefGoogle ScholarPubMed
Baz, A., Garcia-Boyero, A. (1995) The effects of forest fragmentation on butterfly communities in central Spain. J. Biogeogr. 22, 129–140.CrossRefGoogle Scholar
Becker, P., Moure, J. S., Peralta, F. J. A. (1991) More about Euglossine bees in Amazonian forest fragments. Biotropica 23, 586–591.CrossRefGoogle Scholar
Berge, G., Nordal, I., Hestmark, G. (1998) The effect of breeding systems and pollination vectors on the genetic variation of small plant populations within an agricultural landscape. Oikos 81, 17–29.CrossRefGoogle Scholar
Bigger, D. S. (1999) Consequences of patch size and isolation for a rare plant: pollen limitation and seed predation. Nat. Areas J. 19, 239–244.Google Scholar
Bond, W. J. (1994) Do mutualisms matter? Assessing the impact of pollinator and disperser disruption on plant extinction. Phil. Trans. R. Soc. Lond. B 344, 83–90.Google Scholar
Bond, W. J. (1995) Assessing the risk of plant extinction due to pollinator and dispersal failure pp. 131–146Extinction Rates (edited byLawton, J. H., May, R. M.) Oxford University Press,London.CrossRefGoogle Scholar
Bond, W.J., Midgley, J., Vlok, J. (1988) When is an island not an island? Insular effects and their causes in fynbos shrublands. Oecologia 77, 515–521.CrossRefGoogle Scholar
Bosch, M., Waser, N. M. (1999) Effects of local density on pollination and reproduction in Delphinium nuttallianum and Aconitum columbianum (Ranunculaceae). Am. J. Bot. 86, 871–879.CrossRefGoogle ScholarPubMed
Bowers, M. A. (1985) Bumble bee colonization, extinction, and reproduction in subalpine meadows in northeastern Utah. Ecology 66, 914–927.CrossRefGoogle Scholar
Bronstein, J. L. (1995) The plant-pollinator landscape. InMosaic Landscapes and Ecological Processes (edited byHansson, L., Fahrig, L., Merriam, G.) Chapman and Hall, London.Google Scholar
Brown, K. S., Hutchings, R. W. (1997) Disturbance, fragmentation, and the dynamics of diversity in Amazonian forest butterflies pp. 91–110 In Tropical Forest Remnants: Ecology, Management, and Conservation of Fragmented Communities, (edited byLaurance, W. F., Bierregaard, Jr.) University of Chicago Press, Chicago.Google Scholar
Brown, J. H., Kodric-Brown, A. (1997) Turnover rates in insular biogeography: effect of immigration rates on extinction. Ecology 58, 445–449.CrossRefGoogle Scholar
Buchman, S. L., Nabhan, G. P. (1996) The Forgotten Pollinators, Island Press, Washington D.C.Google Scholar
Burd, M. (1994) Bateman's principle and plant reproduction: the role of pollen limitation in fruit and seed set. Bot. Rev. 60, 83–139.CrossRefGoogle Scholar
Byers, D. (1995) Pollen quantity and quality as explanations for low seed set in small populations exemplified by Eupatorium (Asteraceae). Am. J. Bot. 82, 1000–1006.CrossRefGoogle Scholar
Cane, J. H. (1991) Soils of ground-nesting bees (Hymenoptera: Apoidea): texture, moisture, cell depth and climate. J. Kans. Entomol. Soc. 69, 238–247.Google Scholar
Cane, J. H. (2001) Habitat fragmentation and native bees: a premature verdict?. Conserv. Ecol. 5 3 [online] URL http://www.consecol.org/Vol5/iss1/art2.Google Scholar
Cane, J. H., Tepedino, V. J. (2001) Causes and extent of declines among native North American invertebrate pollinators: detection, evidence, and consequences. Conserv. Ecol. 5 1 [online] URL: http://www.consecol.org/Vol5/iss1/art1.Google Scholar
Collinge, S. K. (2000) Effects of grassland fragmentation on insect species loss, colonization, and movement patterns. Ecology 81, 2211–2226.CrossRefGoogle Scholar
Conner, J. K., Neumeier, R. (1995) Effects of black mustard population size on the taxonomic composition of pollinators. Oecologia 104, 218–224.CrossRefGoogle ScholarPubMed
Corbet, S. A. (2000) Conserving compartments in pollination webs. Conserv. Biol. 14, 1229–1231.CrossRefGoogle Scholar
Costin, B. A., Morgan, J. W., Young, A. G. (2001) Reproductive success does not decline in fragmented populations of Leucochrysum albicans subsp. albicans var. tricolor (Asteraceae). Biol. Conserv. 98, 273–284.CrossRefGoogle Scholar
Cunningham, S. A. (2000a) Depressed pollination in habitat fragments causes low fruit set. Proc. R. Soc. Lond. B 267, 1149–1152.CrossRefGoogle ScholarPubMed
Cunningham, S. A. (2000b) Effects of habitat fragmentation on the reproductive ecology of four plant species in mallee woodland. Conserv. Biol. 14, 758–768.CrossRefGoogle Scholar
Dafni, A. (1992) Pollination Ecology: A Practical Approach 250Oxford University Press, Oxford, UK.Google Scholar
Debinski, D. M., Holt, R.D. (2000) A survey and overview of habitat fragmentation experiments. Conserv. Biol. 14, 342–355.CrossRefGoogle Scholar
Demauro, M. M. (1993) Relationship of breeding system to rarity in the Lakeside daisy ( Hymenoxys acaulis var. glabra ). Conserv. Biol. 7, 542–550.CrossRefGoogle Scholar
Dick, C. W. (2001) Genetic rescue of remnant tropical trees by an alien pollinator. Proc. R. Soc. Lond. B 268, 2391–2396.CrossRefGoogle ScholarPubMed
Didham, R.K., Ghazoul, J., Stork, N.E., Davis, A. J. (1996) Insects in fragmented forests: a functional approach. Trends Ecol. Evol. 11, 255–260.CrossRefGoogle ScholarPubMed
Edwards, M. (1996) Optimising habitats for bees in the United Kingdom: a review of recent conservation action The Conservation of Bees Linnean Society Symposium Series no. 18 (edited by Matheson, R. O., Buchmann, S. L., O'Toole, C., Westrich, P., Williams, I. H.) Academic Press London.Google Scholar
Ellstrand, N. C., Elam, D. R. (1993) Population genetic consequences of small population size: Implications for plant conservation. Annu. Rev. Ecol. Syst. 24, 217–242.CrossRefGoogle Scholar
Elmqvist, T. (2000) Pollinator extinction in the Pacific Islands. Conserv. Biol. 14, 1237–1239.Google Scholar
Eriksson, O., Ehrlén, J. (1992) Seed and microsite limitation of recruitment in plant populations. Oecologia 91, 360–364.CrossRefGoogle ScholarPubMed
Feinsinger, P., Linhart, Y. B., Busby, W. H., Murray, K. G. (1987) Disturbance, pollinator predictability, and pollination success among Costa Rican cloud forest plants. Ecology 68, 1294–1305.CrossRefGoogle Scholar
Field, L. F. (2001) Consequences of habitat fragmentation for the pollination of grassland wildflowers in KwaZulu-Natal, South Africa. Unpublished MSc thesis (University of Natal).Google Scholar
Fischer, B. L. (1998) Insect behaviour and ecology in conservation: preserving functional species interactions. Ann. Entomol. Soc. Am. 91, 155–158.CrossRefGoogle Scholar
Fischer, M., Matthies, D. (1997) Mating structure and inbreeding and outbreeding depression in the rare plant Gentianella germanica (Gentianaceae). Am. J. Bot. 84, 1685–1692.CrossRefGoogle ScholarPubMed
Fritz, A., Nilsson, L. A. (1994) How pollinator-mediated mating varies with population size in plants. Oecologia 100, 451–462.CrossRefGoogle ScholarPubMed
Ghazoul, J., McLeish, M. (2001) Reproductive ecology of tropical forest trees in logged and fragmented habitats in Thailand and Costa Rica. Plant. Ecol. 153, 335–345.CrossRefGoogle Scholar
Gigord, L., Picot, F., Shykoff, J. A. (1999) Effects of habitat fragmentation on Dombeya acutangula (Sterculiaceae), a native tree on La Réunion (Indian Ocean). Biol. Conserv. 88, 43–51.CrossRefGoogle Scholar
Givnish, T. J. (2001) The rise and fall of plant species: a population biologist's perspective. Am. J. Bot. 88, 1928–1934.CrossRefGoogle Scholar
Golden, D. M., Paige, K. N. (1995) Inbreeding depression, environmental stress, and population size variation in scarlet gilia ( Ipomopsis aggregata ). Conserv. Biol. 126, 133.Google Scholar
Husband, B. C., Schemske, D. W. (1996) Evolution of the magnitude and timing of inbreeding depression in plants. Evolution 50, 54–70.CrossRefGoogle ScholarPubMed
Ingvarsson, P. K., Lundberg, S. (1995) Pollinator functional response and plant population dynamics: pollinators as a limiting resource. Evol. Ecol. 9, 421–428.CrossRefGoogle Scholar
Janzen, D. H. (1974) The deflowering of Central America. Nat. Hist. 84, 48–53.Google Scholar
Jennersten, O. (1988) Pollination in Dianthus deltoides (Caryophyllaceae): effects of habitat fragmentation on visitation and seed set. Conserv. Biol. 2, 359–366.CrossRefGoogle Scholar
Johnson, S. D., Steiner, K. E. (2000) Generalization versus specialization in plant pollination systems. Trends Ecol. Evol. 15, 140–143.CrossRefGoogle ScholarPubMed
Johnson, S. D., Steiner, K. E. (2003) Specialized pollination systems in southern Africa S. Afr. J. Sci. (in press).Google Scholar
Karoly, K. (1992) Pollinator limitation in the facultatively autogamous annual, Lupinus nanus (Leguminosae). Am. J. Bot. 79, 49–56.CrossRefGoogle Scholar
Kearns, C. A., Inouye, D. W. (1997) Pollinators, flowering plants, and conservation biology. Bioscience 47, 297–307.CrossRefGoogle Scholar
Kearns, C. A., Inouye, D. W., Waser, N. M. (1998) Endangered mutualisms: the conservation of plant-pollinator interactions. Annu. Rev. Ecol. Syst. 29, 83–112.CrossRefGoogle Scholar
Kemper, J., Cowling, R. M., Richardson, D. M. (1999) Fragmentation of South African Renosterveld shrublands: effects on plant community structure and conservation implications. Biol. Conserv. 90, 103–111.CrossRefGoogle Scholar
Kéry, M., Matthies, D., Spillman, H. (2000) Reduced fecundity and offspring performance in small populations of the declining grassland plants Primula veris and Gentiana lutea. J. Ecol. 88, 17–30.CrossRefGoogle Scholar
Kevan, P. G. (1999) Pollinators as bioindicators of the state of the environment: species, activity and diversity. Agric. Ecosyst. Environ. 74, 373–393.CrossRefGoogle Scholar
Klemm, M. (1996) Man-made bee habitats in the anthropogenous landscape of central Europe: substitutes for threatened or destroyed riverine habitats? The Conservation of Bees Linnean Society Symposium Series pp. 17–31 (edited byMatheson, A., Buchmann, S.L., O'Toole, C., Westrich, P., Williams, I. H.) Academic Press, London.Google Scholar
Kremen, C., Ricketts, T. (2000) Global perspectives on pollination disruptions. Conserv. Biol. 14, 1226–1228.CrossRefGoogle Scholar
Kunin, W. E. (1993) Sex and the single mustard: population density and pollinator behaviour effects on seed set. Ecology 74, 2145–2160.CrossRefGoogle Scholar
Kunin, W. E. (1997) Population biology and rarity: on the complexity of density dependence in insect-plant interactions pp.150–173The Biology of Rarity: Causes and Consequences of Rare-Common Differences (edited byKunin, W. E., Gaston, K. J.) Chapman and Hall, London.CrossRefGoogle Scholar
Kwak, M. M. (1987) Pollination and pollen flow disturbed by honey bees in bumblebee-pollinated Rhinanthus populations?pp.273–284. InDisturbance in Grasslands: Causes, Effects and Processes, Van Andel, J., Bakker, J. P., Snaydon, R. W.Dr W. Junk Publishers, Dordrecht.CrossRefGoogle Scholar
Ladley, J. L., Kelly, D. (1995) Explosive New Zealand mistletoe. Nature 378, 766.CrossRefGoogle Scholar
Lamont, B. B., Klinkhamer, P. G. L., Witkowski, E. T. F. (1993) Population fragmentation may reduce fertility to zero in Banksia goodii – a demonstration of the Allee effect. Oecologia 94, 446–450.CrossRefGoogle ScholarPubMed
Larson, B. M. H., Barret, S. C. H. (1998) Reproductive biology of island and mainland populations of Primula mistassinica (Primulaceae) on Lake Huron shorelines. Can. J. Bot. 76, 1819–1827.Google Scholar
Larson, B. M. H., Barrett, S. C. H. (2000) A comparative analysis of pollen limitation in flowering plants. Biol. J. Linnean Soc. Lond. 69, 503–520.CrossRefGoogle Scholar
Leach, M. K., Givnish, T. J. (1996) Ecological determinants of species loss in remnant prairies. Science 273, 1555–1558.CrossRefGoogle Scholar
Lee, T. D. (1988) Patterns of fruit and seed production pp.179–263Reproductive Ecology of Plants, (edited byLovest-Doust, J., Lovest-Doust, L.) Oxford University Press,Oxford, UK.Google Scholar
Lennartsson, T. (2002) Extinction thresholds and disrupted plant-pollinator interactions in fragmented plant populations. Ecology 83, 3060–3072.Google Scholar
Les, D. H., Reinartz, J. A., Esselman, E. J. (1991) Genetic consequences of rarity in Aster furatus (Asteraceae), a threatened, self-incompatible plant. Evolution 45, 1641–1650.CrossRefGoogle Scholar
Lindberg, A. B., Olesen, J. M. (2001) The fragility of extreme specialization: Passiflora mixta and its pollinating hummingbird Ensifera ensifera. J. Trop. Ecol. 17, 323–329.CrossRefGoogle Scholar
Lindsey, A. H. (1984) Reproductive biology of Apiaceae. I. Floral visitors to Thaspium and Zizia and their importance in pollination. Am. J. Bot. 71, 375–387.CrossRefGoogle Scholar
Linhart, Y. B., Feinsinger, P. (1980) Plant-hummingbird interactions: effects of island size and degree of specialization on pollination. J. Ecol. 68, 745–760.CrossRefGoogle Scholar
MacArthur, R. H., Wilson, E. O. (1963) An equilibrium theory of insular biogeography. Evolution 17, 373–387.CrossRefGoogle Scholar
MacArthur, R. H., Wilson, E. O. (1967) The Theory of Island Biogeography Princeton University Press, New Jersey.Google Scholar
Mahy, G., De Sloover, J., Jacquemart, A. (1998) The generalist pollination system and reproductive success of Calluna vulgaris in the Upper Ardene. Can. J. Bot. 76, 1843–1851.Google Scholar
Marlin, J. C., erge, W. E. (2001) The native bee fauna of Carlinville, Illinois, revisited after 75 years: a case for persistence. Conserv. Ecol. 5 9 [online] URL:http://www.consecol.org/Vol5/iss1/art2.Google Scholar
Mawdsley, N. A., Compton, S. G., Whittaker, R. J. (1998) Population persistence, pollination mechanisms, and figs in fragmented tropical landscapes. Conserv. Biol. 12, 1416–1420.CrossRefGoogle Scholar
Memmott, J. (1999) The structure of a plant-pollinator food web. Ecol. Lett. 2, 276–280.CrossRefGoogle ScholarPubMed
Menges, E. S. (1991) Seed germination percentage increases with population size in a fragmented prairie species. Conserv. Biol. 5, 158–164.CrossRefGoogle Scholar
Molano-Flores, B., Hendrix, S. D., Heard, S. B. (1999) The effect of population size on stigma pollen load, fruit set, and seed set in Allium stellatum Ker. (Liliaceae). Int. J. Plant Sci. 160, 753–757.CrossRefGoogle Scholar
Morgan, J. W. (1999a) Effects of population size on seed production and germinability in an endangered, fragmented grassland plant. Conserv. Biol. 13, 266–273.CrossRefGoogle Scholar
Morgan, J. W. (1999b) Defining grassland fire events and the response of perennial plants to annual fire in temperate grasslands of south-eastern Australia. Plant Ecol. 144, 127–144.CrossRefGoogle Scholar
Motten, A. F. (1986) Pollination ecology of the spring wildflower community of a temperate deciduous forest. Ecol. Monogr. 56, 21–42.CrossRefGoogle Scholar
Murcia, C. (1996) Forest fragmentation and the pollination of neotropical plants Forest Patches In Tropical Landscapes Schel has J. Greenberg R. Washington D.C., USA Island Press.Google Scholar
Murren, C. J. (2002) Effects of habitat fragmentation on pollination: pollinators, pollinia viability and reproductive success. J. Ecol. 90, 100–107.CrossRefGoogle Scholar
Nabhan, G. P. (1996) Global list of threatened vertebrate wildlife species serving as pollinators for crops and wild plants 16 Tucson Forgotten Pollinators Campaign, Arizona-Sonora Desert Museum.Google Scholar
Nason, J. D., Hamrick, J. L. (1997) Reproductive and genetic consequences of forest fragmentation: two case studies of neotropical canopy trees. J. Hered. 88, 264–276.CrossRefGoogle Scholar
Neal, P. R. (1998) Pollinator restoration. Trends Ecol. Evol. 13, 132–133.CrossRefGoogle ScholarPubMed
Nilsson, L. A., Rabakonandrianina, E., Razananaivo, R., Randriamanindry, J.-J. (1992) Long pollinia on eyes: hawk-moth pollination of Cynorkis uniflora Lindley (Orchidaceae) in Madagascar. Bot. J. Linn. Soc. 109, 145–160.CrossRefGoogle Scholar
Nishihiro, J., Washitani, I. (1998) Effect of population spatial structure on pollination and seed set of a clonal distylous plant, Persicaria japonica (Polygonaceae). J. Plant Res. 111, 547–555.CrossRefGoogle Scholar
Noss, R. F., Csuti, B. (1997) Habitat fragmentation, pp.269–304 In Principles of Conservation Biology, 2nd Edn. (edited byMeffe, G. K., Carroll, C. R.) Associates, Inc. Publishers, Sunderland Sinauer.Google Scholar
Novacek, M. J., Cleland, E. E. (2001) The current biodiversity extinction event: scenarios for mitigation and recovery. Proc. Nat. Acad. Sci. USA 98, 5466–5470.CrossRefGoogle ScholarPubMed
Olesen, J. M., Jain, S. K. (1994) Fragmented plant populations and their lost interactions pp.417–426Conservation Genetics, (edited byLoeschcke, V., Tomiuk, J., Jain, S. K.) Birkhäuser Verlag, Basel/Switzerland.CrossRefGoogle Scholar
Ollerton, J. (1996) Reconciling ecological processes with phylogenetic patterns: the apparent paradox of plant-pollinator systems. J. Ecol. 84, 767–769.CrossRefGoogle Scholar
Oostermeijer, J. G. B., van Eijck, M. W., den Nijs, H. C. M. (1994) Offspring fitness in relation to population size and genetic variation in the rare perennial plant Gentiana pneumonanthe (Gentianaceae). Oecologia 97, 289–296.CrossRefGoogle ScholarPubMed
Oostermeijer, J. G., Luijten, S. H., KÍenová, Z. V., Den Nijs, H. C. M. (1998) Relationships between population and habitat characteristics and reproduction of the rare Gentiana pneumonanthe L. Conserv. Biol. 12, 1042–1053.CrossRefGoogle Scholar
O'Toole, C., Raw, A. (1991) Bees of the World. London, Blandford.Google Scholar
Powell, A. H., Powell, G. V. N. (1987) Population dynamics of male euglossine bees in Amazonian forest fragments. Biotropica 19, 176–179.CrossRefGoogle Scholar
Pyke, G. H., Pulliam, H. R., Charnov, E. L. (1977) Optimal foraging: a selective review of theory and test. Q. Rev. Biol. 52, 137–154.CrossRefGoogle Scholar
Rasmussen, I. R., Brødsgaard, B. (1992) Gene flow inferred from seed dispersal and pollinator behaviour compared to DNA analysis of restriction site variation in a patchy population of Lotus corniculatus L. Oecologia 89, 277–283.CrossRefGoogle Scholar
Rathcke, B. J., Jules, E. S. (1993) Habitat fragmentation and plant-pollinator interactions. Curr. Sci. 65, 273–277.Google Scholar
Renner, S. S. (1999) Effects of habitat fragmentation on plant pollinator interactions in the tropics pp.339–360.In Dynamics of Tropical Communities, (edited byPrins, H. H., Brown, N. D.) Blackwell Scientific,London.Google Scholar
Richards, A. J. (1986) Plant Breeding Systems, Unwin Hyman, London.Google Scholar
Ricketts, T.H. (2001) The matrix matters: effective isolation in fragmented landscapes. Am. Nat. 158, 87–89.CrossRefGoogle ScholarPubMed
Robertson, A. W., Kelly, D., Ladley, J. J., Sparrow, A. D. (1999) Effects of pollinator loss on endemic New Zealand mistletoes (Loranthaceae). Conserv. Biol. 13, 499–508.CrossRefGoogle Scholar
Robinson, G. R., Quinn, J. F. (1988) Extinction, turnover and species diversity in an experimentally fragmented California annual grassland community. Oecologia 76, 71–82.CrossRefGoogle Scholar
Rocha, O. J., Aguilar, G. (2001) Reproductive biology of the dry forest tree Enterolobium cyclocarpum (Guanacaste) in Costa Rica: a comparison between trees left in pasture and trees in continuous forest. Am. J. Bot. 88, 1607–1614.CrossRefGoogle ScholarPubMed
Roll, J., Mitchell, R.J., Cabin, R. J., Marshall, D. L. (1997) Reproductive success increases with local density of conspecifics in a desert mustard ( Lesquerella fendleri ). Conserv. Biol. 11, 738–746.CrossRefGoogle Scholar
Rolstad, J. (1991) Consequences of forest fragmentation for the dynamics of bird populations: conceptual issues and the evidence. Biol. J. Linn. Soc. 42, 149–163.CrossRefGoogle Scholar
Roubik, D. W. (2001) Ups and downs in pollinator populations: when is there a decline?. Conserv. Ecol. 5 2 [online] URL:http://www.consecol.org/5/iss1/art 2.Google Scholar
Sala, O. E., Chapin, F. S. III, Armesto, J. J., Berlow, E., Bloomfield, J., Dirzo, R., Huber-Sanwald, E., Huenneke, L. F., Jackson, R. B., Kinzig, A., Leemans, R., Lodge, D. M., Mooney, H. A., Oesterheld, M., Poff, N. L., Sykes, M. T., Walker, B.H., Walker, M., Wall, D.H. (2000) Global biodiversity scenarios for the year 2100. Science 287, 1770–1774.CrossRefGoogle ScholarPubMed
Samways, M. J. (1993) A spatial and process sub-regional framework for insect and biodiversity conservation research and management pp.1–28. In Perspectives on Insect Conservation, (edited byGaston, K. J., New, T. R., Samways, M. J.) Intercept Ltd, Hampshire, UK.Google Scholar
Saunders, D. A., Hobbs, R. J., Margules, C. R. (1991) Biological consequences of habitat fragmentation: a review. Conserv. Biol. 5, 18–32.CrossRefGoogle Scholar
Schoen, D. J., Lloyd, D. G. (1992) Self- and cross-fertilization in plants. III Methods for studying modes and functional aspects of self-fertilization. Int. J. Plant Sci. 153, 381–393.CrossRefGoogle Scholar
Schulke, B., Waser, N. M. (2001) Long-distance pollinator flights and pollen dispersal between populations of Delphinium nuttallianum. Oecologia 127, 237–245.CrossRefGoogle ScholarPubMed
Schultz, C. B., Crone, E. E. (2001) Edge-mediated dispersal behaviour in a prairie butterfly. Ecology 82, 1879–1892.CrossRefGoogle Scholar
Sih, A., Baltus, M. (1987) Patch size, pollinator behaviour, and pollinator limitation in catnip. Ecology 68, 1679–1690.CrossRefGoogle ScholarPubMed
Spears, E. E. (1987) Island and mainland pollination ecology of Centrosema virginianum and Opuntia stricta. J. Ecol. 75, 351–362.Google Scholar
Steffan-Dewenter, I., Tscharntke, T. (1999) Effects of habitat isolation on pollinator communities and seed set. Oecologia 121, 432–440.CrossRefGoogle ScholarPubMed
Steiner, K. E. (1993) Has Ixianthes (Scrophulariaceae) lost its special bee?. Plant Syst. Evol. 185, 7–16.CrossRefGoogle Scholar
Steiner, K. E., Whitehead, V. B. (1996) The consequences of specialization for pollination in a rare South African shrub, Ixianthes retzioides (Scrophulariaceae). Plant Syst. Evol. 201, 131–138.CrossRefGoogle Scholar
Summerville, K. S., Crist, T. O. (2001) Effects of experimental habitat fragmentation on patch use by butterflies and skippers (Lepidoptera). Ecology 82, 1360–1370.CrossRefGoogle Scholar
Thomas, J. A. (1996) The case for a science-based strategy for conserving threatened butterfly populations in the UK and north Europe pp.1–6.In Species Survival in Fragmented Landscapes (edited bySettele, J., Margules, C. R., Poschlod, P., Henle, K.) Kluwer Academic,Amsterdam.Google Scholar
Thomson, J. D. (2001) Using pollination deficits to infer pollinator declines: can theory guide us?. Conserv. Ecol. 5 6 [online] URL: http://www.consecol.org/5/iss1/art 6.Google Scholar
Turnbull, L. A., Crawley, M. J., Rees, M. (2000) Are plants seed-limited? A review of seed sowing experiments. Oikos 88, 225–238.CrossRefGoogle Scholar
Turner, I. M. (1996) Species loss in fragments of tropical rain forest: a review of the evidence. J. Appl. Ecol. 33, 200–209.CrossRefGoogle Scholar
Van Treuren, R., Bijlsma, R., Ouborg, N. J., Kwak, M. M. (1994) Relationships between plant density, outcrossing rates and seed set in natural and experimental populations of Scabiosa columbaria. J. Evol. Biol. 7, 287–302.CrossRefGoogle Scholar
Vandermeer, J., Hoffman, B., Krantz-Ryan, S. L., Wijayratne, U., Buff, J.Franciscus, V. (2001) Effect of habitat fragmentation on gypsy moth ( Lymantria dispar L.) dispersal: the quality of the matrix. Am. Midl. Nat. 145, 188–193.CrossRefGoogle Scholar
Waddington, K. (1983) Foraging behaviour of pollinators Pollination Biology pp.222–229 (edited byReal, L.) Academic Press, Orlando.Google Scholar
Waser, N. M. (1978) Interspecific pollen transfer and competition between co-occurring plant species. Oecologia 36, 223–236.CrossRefGoogle ScholarPubMed
Waser, N. M., Price, M. V. (1991) Outcrossing distance effects in Delphinium nelsonii: pollen loads, pollen tubes, and seed set. Ecology 72, 171–179.CrossRefGoogle Scholar
Waser, N. M., Chittka, L., Price, M. V., Williams, N. M., Ollerton, J. (1996) Generalization in pollination systems, and why it matters. Ecology 77, 1043–1060.CrossRefGoogle Scholar
Washitani, I. (1996) Predicted genetic consequences of strong fertility selection due to pollinator loss in an isolated population of Primula sieboldii. Conserv. Biol. 10, 59–64.CrossRefGoogle Scholar
Weller, S. G. (1994) The relationship of rarity to plant reproductive biology Restoration of Endangered Species pp.92–117. (edited byBowles, M. L., Whelan, C. J.) Cambridge University Press, Cambridge.Google Scholar
Westerbergh, A., Saura, A. (1994) Gene flow and pollinator behaviour in Silene dioica populations. Oikos 71, 215–224.CrossRefGoogle Scholar
Westrich, P. (1996) Habitat requirements of central European bees and the problems of partial habitats Linnean Society Symposium Series no. 18 pp.1–16. In The Conservation of Bees (edited byMatheson, A., Buchmann, S. L., O'Toole, C., Westrich, P., Williams, I. H.) Academic Press,London.Google Scholar
White, G. M., Boshier, D. H., Powell, W. (2002) Increased pollen flow counteracts fragmentation in a tropical dry forest: an example from Swietenia humilis Zuccarini. Proc. Nat. Acad. Sci. USA 99, 2038–2042.CrossRefGoogle Scholar
Williams, N., Minckley, R., Silviera, F. (2001) Variation in native bee faunas and its implications for detecting community changes. Conserv. Ecol. 5 7 [online] URL: http://www.consecol.org/ 2.Google Scholar
Wolf, A. T., Harrison, S. P. (2001) Effects of habitat size and patch isolation on reproductive success of the serpentine morning glory. Conserv. Biol. 15, 111–121.CrossRefGoogle Scholar
Young, A., Merriam, H. G. (1994) Effects of forest fragmentation on the spatial genetic structure of Acer saccharum Marsh. (sugar maple) populations. Heredity 72, 201–208.CrossRefGoogle Scholar
Young, A., Boyle, T., Brown, T. (1996) The population genetic consequences of habitat fragmentation for plants. Trends Ecol. Evol. 11, 413–418.CrossRefGoogle ScholarPubMed
Zink, R. A., Wheelwright, N. T. (1997) Facultative self-pollination in island irises. Am. Midl. Nat. 137, 72–78.CrossRefGoogle Scholar