Biodiversity and Conservation

, Volume 23, Issue 4, pp 963–978 | Cite as

Urban sprawl and species movement may decimate natural plant diversity in an Afro-tropical city

  • Alfan A. RijaEmail author
  • Abubakari Said
  • Kuruthumu A. Mwamende
  • Shombe N. Hassan
  • Seif S. Madoffe


Although urban sprawl is increasingly becoming a worldwide problem, the effects associated with urbanization on local biodiversity particularly in the developing countries, is still poorly understood. We investigated plant species richness along urban–rural gradients in an Afro-tropical metropolitan Morogoro city in Tanzania, and examined patterns of species movement by humans within and outside the city and its potential impact on habitat homogenization of urban ecosystems. Biodiversity information was assessed in 120 sample plots (25 × 25 m) distributed in core urban, sub-urban and peri-urban (rural) zones, while patterns of plant resource use and species movement were surveyed from 120 households in the study area. We found the highest tree species richness in the urban core (82.6 ± 1.4 species) whereas tree density decreased from peri-urban (465.60 ± 152.03 tree/ha) to urban core (244.00 ± 120.86 tree/ha) and species diversity decreased from urban core (α = 2.82 ± 0.01) to peri-urban area (α = 2.61 ± 0.23). Further, the proportion of exotic species was significantly higher (75.6 %) than that of native species in the study area (p = 0.001). Tree community assemblages showed least differences among the study zones (dissimilarity = 10 %) and appear to have been influenced by local cultural differences, species movement as well as local resource use. Furthermore, species movement exhibited a random and multi-directional pattern perpetuated by human and nonhuman factors. Movements were significantly higher between backyard gardens within the city than from outside. Alien species by far outnumbered native plant species moving across urban landscapes, potentially increasing species homogenization. Conservation awareness is needed to avoid habitat homogenization due to problems associated with urban sprawl and to maintain heterogeneous habitats for the urban wildlife.


Biodiversity Species introduction Species movement Species richness Urbanization Urban–rural gradients Morogoro-Tanzania 



We thank the residents of Morogoro municipality for allowing us to carry out research around their homesteads and for taking part during the questionnaire surveys. We thank Andy Bowkett for providing comments on the earlier draft of this paper and Ms Agnes Sirima for the logistical help. Two anonymous reviewers provided comments on the manuscript.


  1. Bongers F, Poorter L, Sheil D, Hawthorne WD (2009) The intermediate disturbance hypothesis applies to tropical forests, but disturbance contributes little to tree diversity. Eco Lett 12(8):798–805CrossRefGoogle Scholar
  2. Breuste JH (2004) Decision making, planning and design for the conservation of indigenous vegetation within urban development. Landsc Urban Plan 68(4):439–452. doi: 10.1016/S0169-2046(03)00150-6 CrossRefGoogle Scholar
  3. Burton ML, Samuelson LJ, Pan S (2005) Riparian woody plant diversity and forest structure along an urban–rural gradient. Urban Ecosyst 8(1):93–106CrossRefGoogle Scholar
  4. Clarke KR (1993) Non-parametric multivariate analyses of changes in community structure. Aust J Ecol 18:117–143CrossRefGoogle Scholar
  5. Clarke KR, Gorley RN (2006) PRIMER v6: User Manual/Tutorial. Primer-E Ltd, PlymouthGoogle Scholar
  6. Clarke KR, Warwick RM (2001) Change in marine communities: an approach to statistical analysis and interpretation, 2nd edn. Primer-E Ltd, PlymouthGoogle Scholar
  7. Cohen B (2006) Urbanization in developing countries: current trends, future projections, and key challenges for sustainability. Technol Soc 28(1–2):63–80. doi: 10.1016/j.techsoc.2005.10.005 CrossRefGoogle Scholar
  8. Colwell RK (2012) EstimateS: statistical estimation of species richness and shared species from samples. Version 8.2.
  9. Dharani N (2002) Field guide to common trees and shrubs of East Africa. Struik Nat, South AfricaGoogle Scholar
  10. Dow K (2000) Social dimensions of gradients in urban ecosystems. Urban Ecosyst 4:255–275CrossRefGoogle Scholar
  11. Dwyer J, Schroeder H, Gobster P (1991) The significance of urban trees and forests: toward a deeper understanding of values. J Arboric 17(10):276–284Google Scholar
  12. Gotelli NJ, Colwell RK (2001) Quantifying biodiversity: procedures and pitfalls in the measurement and comparison of species richness. Ecol Lett 4(4):379–391CrossRefGoogle Scholar
  13. Henderson SPB, Perkins NH, Nelischer M (1998) Residential lawn alternatives: a study of their distribution, form and structure. Landsc Urban Plan 42(2–4):135–145. doi: 10.1016/S0169-2046(98)00084-X CrossRefGoogle Scholar
  14. Hope D, Gries C, Zhu WX, Fagan WF, Redman CL, Grimm NB et al (2003) Socioeconomics drive urban plant diversity. Proc Natl Acad Sci USA 100:8788–8792PubMedCentralPubMedCrossRefGoogle Scholar
  15. Hore U, Uniyal VP (2008) Diversity and composition of spider assemblages in five vegetation types of Terai conservation area, India. J Arachnol 36:251–258CrossRefGoogle Scholar
  16. Kideghesho JR, Msuya TS (2010) Gender and socio-economic factors influencing domestication of indigenous medicinal plants in the West Usambara Mountains, northern Tanzania. Int J Biodivers Sci Ecosyst Serv Manag 6:3–12CrossRefGoogle Scholar
  17. Kim KH, Pauleit S (2005) Landscape metrics to assess the ecological conditions of city regions: application to Kwangju City, South Korea. Int J Sustain Dev World Ecol 12(3):227–244. doi: 10.1080/13504500509469634 CrossRefGoogle Scholar
  18. Kowarik I (2003) Human agency in biological invasions: secondary releases foster naturalisation and population expansion of alien plant species. Biol Invasions 5(4):293–312Google Scholar
  19. Kuhn I, Brandl R, Klotz S (2004) The flora of German cities is naturally species rich. Evol Ecol Res 6(5):749–764Google Scholar
  20. Mack RN, Lonsdale WM (2001) Humans as global plant dispersers: getting more than we bargained for. Bioscience 51:95–102CrossRefGoogle Scholar
  21. McDonnell M, Hahs A (2008) The use of gradient analysis studies in advancing our understanding of the ecology of urbanizing landscapes: current status and future directions. Landsc Ecol 23(10):1143–1155CrossRefGoogle Scholar
  22. McGranahan G, Satterthwaite D (2003) Urban centers: an assessment of sustainability. Annu Rev Environ Resour 28(1):243–274CrossRefGoogle Scholar
  23. McKinney M (2002) Urbanization, biodiversity, and conservation. Bioscience 52(10):883–890CrossRefGoogle Scholar
  24. McKinney M (2008) Effects of urbanization on species richness: a review of plants and animals. Urban Ecosyst 11(2):161–176CrossRefGoogle Scholar
  25. Morrison MES, Lind EM (1974) East Africa vegetation. Longman, London 257pGoogle Scholar
  26. Msuya TS, Kideghesho JR (2009) The role of traditional management practices in enhancing sustainable use and conservation of medicinal plants in West Usambara Mountains, Tanzania. J Tropi Conserv Sci 2(1):88–105Google Scholar
  27. Myers N, Mittermeier RA, Mittermeier CG, da Fonseca GAB, Kents J (2000) Biodiversity hotspots for conservation priorities. Nature 403:853–858PubMedCrossRefGoogle Scholar
  28. Ortega-Álvarez RN, Rodríguez-Correa HA, MacGregor-Fors I (2011) Trees and the city: diversity and composition along an urban gradient. Int J Ecol 1–8. doi: 10.1155/2011/704084
  29. Pauchard A, Aguayo M, Peña E, Urrutia R (2006) Multiple effects of urbanization on the biodiversity of developing countries: the case of a fast-growing metropolitan area (Concepción, Chile). Biol Conserv 127(3):272–281. doi: 10.1016/j.biocon.2005.05.015 CrossRefGoogle Scholar
  30. Pautasso M (2007) Scale dependence of the correlation between human population presence and vertebrate and plant species richness. Ecol Lett 10(1):16–24PubMedCrossRefGoogle Scholar
  31. Rija AA (2003) Feeding habits, abundance and distribution of pied crow Corvus albus around the Uluguru Mountains. BSc research paper, library of Sokoine University of Agriculture, TanzaniaGoogle Scholar
  32. Rija AA (2010) Incentives for conserving and greening our cities. Tanzania Wildlife Magazine-Kakakuona 57:58–61Google Scholar
  33. Savard JPL, Clergeau P, Mennechez G (2000) Biodiversity concepts and urban ecosystems. Landsc Urban Plan 48(3–4):131–142CrossRefGoogle Scholar
  34. Sax DF, Brown JH, White EP, Gaines SD (2005) The dynamics of species invasions: insights into the mechanisms that limit species diversity. In: Sax DF, Stachowicz JJ, Gaines SD (eds) Species invasions: insights into ecology, evolution and biogeography. Sinauer, Sunderland, pp 447–466Google Scholar
  35. Tait CJ, Daniels CB, Hill RS (2005) Changes in species assemblages within the Adelaide metropolitan area, Australia, 1836–2002. Ecol Appl 15(1):346–359. doi: 10.1890/04-0920 CrossRefGoogle Scholar
  36. von der Lippe M, Kowarik I (2008) Do cities export biodiversity? Traffic as dispersal vector across urban–rural gradients. Divers Distrib 14:18–25CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2014

Authors and Affiliations

  • Alfan A. Rija
    • 1
    Email author
  • Abubakari Said
    • 1
  • Kuruthumu A. Mwamende
    • 2
  • Shombe N. Hassan
    • 1
  • Seif S. Madoffe
    • 3
  1. 1.Faculty of Forestry and Nature ConservationSokoine University of AgricultureMorogoroTanzania
  2. 2.Range Management Section, Department of Animal Science and ProductionSokoine University of AgricultureMorogoroTanzania
  3. 3.Department of Forest BiologyMorogoroTanzania

Personalised recommendations