Beginning in the mid-1980s, I examined hierarchical structure in species' distributions and, with collaborator Wirt Atmar, developed concepts and algorithms for exploring nested subsets of
species in ecological communities. Nestedness occurs when the species
found in smaller fragments constitute nested or 'proper' subsets of those
in progressively richer biotas.
Nested subsets represent a hierarchical pattern of species composition among islands or fragments
The species found in various kinds of ecological communities often comprise nested subsets of those inhabiting richer ones. This phenonenon, termed nested subsets or nestedness, has biogeographic, ecological, and coevolutionary consequences. It also has important implications for biological conservation. The following link accesses AICS Research Inc's website, where the software developed by Wirt Atmar and me can be freely downloaded. The software has the proper citation of:
Atmar, W. & B.D. Patterson. 1995. The nestedness temperature calculator: a visual basic program, including 294 presence-absence matrices. AICS Research, Inc., University Park, NM, and The Field Museum, Chicago.
Nested subsets of mammal species on Southwestern mountaintops,
as determined with the Nestedness Calculator
I periodically revisit and re-evaluate
this paradigm, considering its extensions to other areas of
biogeography, ecology, and evolution. Nested patterns prove to be
amazingly common in nature, and scientists now appreciate
its significance for studying coevolutionary partnerships, especially
mutualisms (plants and their pollinators/seed-dispersers)
and host-parasite systems. A 2009 paper in Ecography (written with Carl Dick and Katha Dittmar) offered a cautionary tale on their application to host-parasite systems. A 2011 paper with Mohammad Abu Baker (in Journal of Arid Environments) examined nestedness of Egyptian rodent assemblages. Nestedness was just one of several community structures examined in a 2012 paper in Global Ecology and Biogeography with the Willig lab at UCONN. I am currently working with Argentinian post-doc Daniela Rodriguez and others on a meta-analysis of community structures in desert small mammal ensembles globally.
Publications on Nestedness
Patterson, B.D. & W. Atmar. 1986. Nested subsets and the structure of insular mammalian faunas and archipelagos. Biological Journal of the Linnean Society 28:65-82. download pdf
Patterson, B.D., C.W. Dick & K. Dittmar. 2009. Nested distributions of bat flies (Diptera: Streblidae) on Neotropical bats: artifact and specificity in host-parasite studies. Ecography 32:481-487. pdf (159 kb)
Abu Baker, M. & B.D. Patterson. 2011. Patterns in the local assembly of Egyptian rodent faunas: co-occurrence and nestedness. Journal of Arid Environments 75:14-19. pdf (504 kb)
Presley, S.J., L.M.Cisneros, B.D. Patterson & M.R. Willig. 2012. Vertebrate meta-community structure along an extensive elevational gradient in the tropics: a comparison of bats, rodents, and birds. Global Ecology and Biogeography 21: 968-976. pdf (950 kb)