Landscape connectivity and the role of small habitat patches as stepping stones: an assessment of the grassland biome in South America

  • Lorena P. Herrera
  • Malena C. Sabatino
  • Florencia R. Jaimes
  • Santiago Saura
Original Paper

Abstract

Connectivity losses lead to a reduction of the amount of habitat resources that can be reached and used by species, and hence to a decline in the ranges and abundance of multiple taxa. Despite the recognized important role of small habitat patches for many species inhabiting fragmented landscapes, their potential contribution as stepping stones for maintaining overall landscape connectivity has received less attention. Using connectivity metrics based on a graph-theoretic approach we (i) quantified the connectivity of grassland patches in a sector of the Pampa region in Argentina, using a range of dispersal distances (from 100 to 10,000 m) representative of the scale of dispersal of different species; (ii) identified the most relevant patches for maintaining overall connectivity; and (iii) studied the importance of small patches (defined for different area thresholds of 5, 20, and 50 ha) as connectivity providers in the landscape. Although grassland patches were in general poorly connected at all distances, some of them were critical for overall connectivity and were found to play different crucial roles in the patch network. The location of small patches in the grassland network allowed them to function as stepping stones, yielding significant connectivity gains for species that move large distances (>5000 m) for the three area thresholds considered. Thus, under the spatial pattern of the studied landscape, species that move long distances would benefit from stepping stones, while less mobile organisms would benefit from, and mostly rely on the largest patches. We recommend that future management activities should (i) aim at preserving the grassland patches with the highest potential as stepping stones to promote landscape-level connectivity; and (ii) pay more attention to the conservation of key small patches, particularly given that usually they are those more vulnerable to land clearing for agriculture.

Keywords

Threatened ecosystems Conservation planning Pampa region Habitat patch networks 

References

  1. Aizen MA, Gleiser G, Sabatino M, Gilarranz LJ, Bascompte J, Verdú M (2016) The phylogenetic structure of plant–pollinator networks increases with habitat size and isolation. Ecol Letters 19:29–36CrossRefGoogle Scholar
  2. Akçakaya HR, Mills G, Doncaster CP (2007) The role of metapopulation conservation. In: Macdonald DW, Service K (eds) Key topics in conservation biology. Blackwell, Oxford, pp 64–84Google Scholar
  3. Baguette M, Blanchet S, Legrand D, Stevens VM, Turlure C (2013) Individual dispersal, landscape connectivity and ecological networks. Biol Rev 88:310–326CrossRefPubMedGoogle Scholar
  4. Barral MP, Maceira NO (2012) Land use planning based on ecosystem service assessment: A case study in the Southeast Pampas of Argentina. Agric Ecosyst Environ 154:34–43CrossRefGoogle Scholar
  5. Baum KA, Haynes KJ, Dillemuth FP, Cronin JT (2004) The matrix enhances the effectiveness of corridors and stepping stones. Ecology 85:2671–2676CrossRefGoogle Scholar
  6. Bowman J, Jaeger JAG, Fahrig L (2002) Dispersal distance of mammals is proportional to home range size. Ecology 83:2049–2055CrossRefGoogle Scholar
  7. Bunn AG, Urban DL, Keitt TH (2000) Landscape connectivity: a conservation application of graph theory. J Environ Manag 59:265–278CrossRefGoogle Scholar
  8. Burel F, Baudry J (2005) Habitat quality and connectivity in agricultural landscapes: the role of land use systems at various scales in time. Ecol Indic 5:305–313CrossRefGoogle Scholar
  9. Burgos JJ, Vidal AL (1951) Los climas de la República Argentina, según la nueva clasificación de Thornthwaite. Servicio Meteorológico Nacional, Buenos AiresGoogle Scholar
  10. Comparatore VM, Martínez MM, Vasallo AI, Barg M, Isacch JP (1996) Abundancia y relaciones con el hábitat de aves y mamíferos en pastizales de Paspalum quadrifarium (paja colorada) manejados con fuego (Provincia de Buenos Aires, Argentina). Interciencia 21:228–237Google Scholar
  11. Correa Ayram CA, Mendoza ME, Pérez Salicrup DR, López Granados E (2014) Identifying potential conservation areas in the Cuitzeo Lake basin, México by multitemporal analysis of landscape connectivity. J Nat Conserv 22:424–453CrossRefGoogle Scholar
  12. Crooks KR, Sanjayan MA (eds) (2006) Connectivity conservation. Cambridge University Press, New YorkGoogle Scholar
  13. Estrada E, Bodin Ö (2008) Using network centrality measures to manage landscape connectivity. Ecol Appl 18:1810–1825CrossRefPubMedGoogle Scholar
  14. Fahrig L (2003) Effects of habitat fragmentation on biodiversity. Annu Rev Ecol Evol Syst 34:487–515CrossRefGoogle Scholar
  15. Fischer J, Lindenmayer DB (2002) Small patches can be valuable for biodiversity conservation: two case studies on birds in southeastern Australia. Biol Conserv 106:129–136CrossRefGoogle Scholar
  16. Fischer J, Sherren K, Stott J, Zerger A, Warren G, Stein J (2009) Toward landscape-wide conservation outcomes in Australia’s temperate grazing region. Front Ecol Environ 8:69–74CrossRefGoogle Scholar
  17. Forman RTT (1995) Land mosaics: the ecology of landscapes and regions. Cambridge University Press, Cambridge/New YorkGoogle Scholar
  18. Forman RTT, Godron M (1986) Landscape ecology. Wiley, NewYorkGoogle Scholar
  19. Fourie L, Rouget M, Lötter M (2015) Landscape connectivity of the grassland biome in Mpumalanga, South Africa. Austral Ecol 40:67–76CrossRefGoogle Scholar
  20. Frangi J (1975) Sinopsis de las comunidades vegetales. Bol Soc Argent Bot 16:29–319Google Scholar
  21. Galpern P, Manseau M, Fall A (2011) Patch-based graphs of landscape connectivity: a guide to construction, analysis and application for conservation. Biol Conserv 144:44–55CrossRefGoogle Scholar
  22. Geldmann J, Barnes M, Coad L, Craigie I (2013) Effectiveness of terrestrial protected areas in reducing habitat loss and population declines. Biol Conserv 161:230–238CrossRefGoogle Scholar
  23. Gerber JD, Rissman A (2012) Land conservation strategies: the dynamic relationship between acquisition and land use planning. Environ Plann 44:1836–1855CrossRefGoogle Scholar
  24. Gilarranz LJ, Sabatino M, Aizen M, Bascompte J (2015) Hot spots of mutualistic networks. J Anim Ecol 84:407–413CrossRefPubMedGoogle Scholar
  25. Hanski I (1999) Metapopulation ecology. Oxford University Press, New YorkGoogle Scholar
  26. Herrera LP, Laterra P (2011) Relative influence of size, connectivity and disturbance history on plant species richness and assemblages in fragmented grasslands. Appl Veg Sci 14:181–188CrossRefGoogle Scholar
  27. Herrera L, Sabatino M, Gastón A, Saura S (2016) Grassland connectivity explains entomophilous plant species assemblages in an agricultural landscape of the Pampa region, Argentina. Austral Ecol. doi:10.1111/aec.12468 Google Scholar
  28. INTA (1991) Cartas de suelo de la República Argentina, E 1:50000. Ediciones INTA, Buenos AiresGoogle Scholar
  29. Jiménez MD, Ramírez A, Mola I, Casado MA, Balaguer L (2015) Use of restoration plantings to enhance bird seed dispersal at the roadside: failures and prospects. J Environ Eng Landsc Manag 23:301–311Google Scholar
  30. Joppa LN, Pfaff A (2011) Global protected area impacts. Proc R Soc Lond 278:1633–1638CrossRefGoogle Scholar
  31. Kristensen MJ, Lavornia JM, Leber V, Pose MP, Dellapé P, Salle A, Braccalente L, Giarratano M, Higuera M (2014) Estudios para la conservación de la Pampa Austral. I. Diagnóstico de la biodiversidad local. Rev Estud Amb 2:105–118Google Scholar
  32. Laurance WF (2000) Do edge effects occur over large spatial scales? TEE 15:134–135Google Scholar
  33. Laurance WF, Useche DC, Rendeiro J, Kalka M, Bradshaw CJA et al (2012) Averting biodiversity collapse in tropical forest protected areas. Nature 489:290–294CrossRefPubMedGoogle Scholar
  34. Levins R (1969) Some demographic and genetic consequences of environmental heterogeneity for biological control. Bull Entomol Soc Am 15:237–240Google Scholar
  35. Li BL, Archer S (1997) Weighted mean patch size: a robust index for quantifying landscape structure. Ecol Modell 102:353–361CrossRefGoogle Scholar
  36. Logsdon RA, Chaubey I (2013) A quantitative approach to evaluating ecosystem services. Ecol Modell 257:57–65CrossRefGoogle Scholar
  37. MacArthur RH, Wilson EO (1967) The theory of island biogeography. Princeton University Press, New JerseyGoogle Scholar
  38. Manning AD, Gibbons P, Lindenmayer DB (2009) Scattered trees: a complementary strategy for facilitating adaptive responses to climate change in modified landscapes? J Appl Ecol 46:915–919CrossRefGoogle Scholar
  39. Newbold T, Hudson LN, Arnell AP, Contu S, De Palma A, Ferrier S et al (2016) Has land use pushed terrestrial biodiversity beyond the planetary boundary? A global assessment. Science 353:288–291CrossRefPubMedGoogle Scholar
  40. Pascual-Hortal L, Saura S (2006) Comparison and development of new graph-based landscape connectivity indices: towards the priorization of habitat patches and corridors for conservation. Landsc Ecol 21:959–967CrossRefGoogle Scholar
  41. Rey Benayas JM, Bullock JM, Newton AC (2008) Creating woodland islets to reconcile ecological restoration, conservation, and agricultural land use. Front Ecol Environ 6:329–336CrossRefGoogle Scholar
  42. Rösch V, Tscharntke T, Scherber C, Batáry P (2015) Biodiversity conservation across taxa and landscapes requires many small as well as single large habitat fragments. Oecologia 179(1):209–222CrossRefPubMedGoogle Scholar
  43. Sabatino M, Maceira N, Aizen MA (2010) Direct effects of habitat area on interaction diversity in pollination webs. Ecol Appl 20:1491–1497CrossRefPubMedGoogle Scholar
  44. Sáez A, Sabatino M, Aizen M (2014) La diversidad floral del borde afecta la riqueza y abundancia de visitantes florales nativos en cultivos de girasol. Ecol Austral 24:94–102Google Scholar
  45. Saura S, de la Fuente B (2017) Connectivity as the amount of reachable habitat: conservation priorities and the roles of habitat patches in landscape networks. In: Gergel SE, Turner MG (eds) Learning landscape ecology, 2nd edn. Springer, New YorkGoogle Scholar
  46. Saura S, Pascual-Hortal L (2007) A new habitat availability index to integrate connectivity in landscape conservation planning: comparison with existing indices and application to a case study. Landsc Urban Plan 83:91–103CrossRefGoogle Scholar
  47. Saura S, Rubio L (2010) A common currency for the different ways in which patches and links can contribute to habitat availability and connectivity in the landscape. Ecography 33:523–537Google Scholar
  48. Saura S, Torné J (2009) Conefor Sensinode 2.2: a software package for quantifying the importance of habitat patches for landscape connectivity. Environ Modell Soft 24:135–139CrossRefGoogle Scholar
  49. Saura S, Estreguil C, Mouton C, Rodríguez-Freire M (2011) Network analysis to assess landscape connectivity trends: application to European forests (1990–2000). Ecol Indic 11:407–416CrossRefGoogle Scholar
  50. Saura S, Bodin Ö, Fortin MJ (2014) Stepping stones are crucial for species’ long-distance dispersal and range expansion through habitat networks. J Appl Ecol 51:171–182CrossRefGoogle Scholar
  51. Saura S, Bastin L, Battistella L, Mandrici A, Dubois G (2017) Protected areas in the world’s ecoregions: how well connected are they? Ecol Indic 76:144–158CrossRefPubMedPubMedCentralGoogle Scholar
  52. Smith AM, Green DM (2005) Dispersal and the metapopulation paradigm in amphibian ecology and conservation: are all amphibian populations metapopulations? Ecography 28:110–128CrossRefGoogle Scholar
  53. Soriano A, León RJC, Sala OE, Lavado RS, Deregibus VA, Cauéphé MA, Scaglia OA, Velázquez CA, Lemcoff JH (1991) Río de la Plata Grasslands. In: Couplan RT (ed) Natural grasslands. Introduction and Western Hemisphere. Ecosystems of the world. Elsevier, New York, pp 367–407Google Scholar
  54. Stevens VM, Trochet A, Blanchet S, Moulherat S, Clobert J, Baguette M (2013) Dispersal syndromes and the use of life-histories to predict dispersal. Evol Appl 6:630–642CrossRefPubMedPubMedCentralGoogle Scholar
  55. Stickler CM, Nepstad DC, Azevedo AA, McGrath DG (2013) Defending public interests in private lands: compliance, costs and potential environmental consequences of the Brazilian Forest Code in Mato Grosso. Philos Trans R Soc Lond B Biol Sci 368(1619):20120160CrossRefPubMedPubMedCentralGoogle Scholar
  56. Taylor PD, Fahrig L, Henein K, Merriam G (1993) Connectivity is a vital element of landscape structure. Oikos 68:571–572CrossRefGoogle Scholar
  57. Thomson FJ, Moles AT, Auld TD, Kingsford RT (2011) Seed dispersal distance is more strongly correlated with plant height than with seed mass. J Ecol 99:1299–1307CrossRefGoogle Scholar
  58. Tischendorf L, Fahrig L (2000) On the usage and measurement of landscape connectivity. Oikos 90:7–19CrossRefGoogle Scholar
  59. Tulloch AIT, Barnes MD, Ringma J, Fuller RA, Watson JEM (2015) Understanding the importance of small patches of habitat for conservation. J Appl Ecol 53:418–429CrossRefGoogle Scholar
  60. Turner MG, Gardner RH, O’Neill RV (2001) Landscape Ecology in theory and practice. Springer, New YorkGoogle Scholar
  61. Uezu A, Beyer DD, Metzger JP (2008) Can agroforest woodlots work as stepping stones for birds in the Atlantic forest region? Biod Conserv 17:1907–1922CrossRefGoogle Scholar
  62. Urban D, Keitt T (2001) Landscape connectivity: a graph theoretical perspective. Ecology 82:1205–1218CrossRefGoogle Scholar
  63. Urban D, Minor ES, Treml EA, Schick RS (2009) Graph models of habitat mosaics. Ecol Lett 12:260–273CrossRefPubMedGoogle Scholar
  64. Valicenti R, Farina E, Scaramuzzino R, D’Alfonso C (2010) Ordenación de la vegetación en el paisaje Boca de la Sierras (Azul, Sistema de Tandilia). RASADEP 1:111–122Google Scholar

Copyright information

© Springer Science+Business Media B.V. 2017

Authors and Affiliations

  1. 1.Grupo de Estudios de Agroecosistemas y Paisajes Rurales (GEAP), Facultad de Ciencias AgrariasUniversidad Nacional de Mar del PlataBalcarceArgentina
  2. 2.Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)Ciudad Autónoma de Buenos AiresArgentina
  3. 3.Instituto Nacional de Tecnología Agropecuaria, EEA INTABalcarceArgentina
  4. 4.Facultad de Ciencias AgrariasUniversidad Nacional de Mar del PlataBalcarceArgentina
  5. 5.Directorate D: Sustainable ResourcesEuropean Commission, Joint Research Centre (JRC)IspraItaly

Personalised recommendations