Loss and fragmentation of habitat are among the main reasons why biodiversity is decreasing in many places worldwide.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/loss-habitat-causes-double-damage-species-richness
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/science-daily
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/wildlife
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/habitat
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/biodiversity
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/global