Nested Subsets
Beginning in the mid-1980s, I examined hierarchical structure in species' distributions with mentor and collaborator Wirt Atmar, and we 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.
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. David Wright, Greg Mikkelson, and Alan Cutler also contributed importantly to our ideas and ways to test them.
Nested subsets represent a hierarchical pattern of species composition among islands or fragments
AICS Research Inc's website formerly hosted the VisualBasic software developed by Wirt Atmar and me where it could be freely downloaded. The software was cited as:
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.
Unfortunately, this program could not run under later versions of Windows. An improved algorithm for running the analyses (but lacking the visual interface) is now available:
Strona, G., P. Galli, D. Seves, S. Montano, and S. Fattorini. 2014. Nestedness for Dummies (NeD): A user-friendly web interface for exploratory nestedness analysis. Journal of Statistical Software 59: 1-9.
Nested subsets of mammal species on Southwestern mountaintops, as determined with the Nestedness Calculator
I periodically revisited and re-evaluated 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.
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. pdf
Patterson, B.D. 1987. The principle of nested subsets and its implications for biological conservation. Conservation Biology 1:323-334. pdf
Patterson, B.D. 1990. On the temporal development of nested subset patterns of species composition. Oikos 59:330-342. pdf
Patterson, B.D. & J.H. Brown. 1991. Regionally nested patterns of species composition in granivorous rodent assemblages. Journal of Biogeography 18:395-402. pdf
Atmar, W. & B.D. Patterson. 1993. The measure of order and disorder in the distribution of species in fragmented habitat. Oecologia 96:373-382. pdf
Patterson, B.D., V. Pacheco & S. Solari. 1996. Distributions of bats along an elevational gradient in the Andes of south-eastern Peru. Journal of Zoology 240:637-658. pdf
Wright, D.H., B.D. Patterson, G. Mikkelson, A.H. Cutler & W. Atmar. 1998. A comparative analysis of nested subset patterns of species composition. Oecologia 113:1-20. pdf
Patterson, B.D., D. Stotz, S. Solari, J. Fitzpatrick & V. Pacheco. 1998. Contrasting patterns of elevational zonation for birds and mammals in the Andes of southeastern Peru. Journal of Biogeography 25:593-607. pdf
Patterson, B.D. 1999. Contingency and determinism in mammalian biogeography: the role of history. Journal of Mammalogy 80:345-360. pdf
Patterson, B.D. & W. Atmar. 2000. Analyzing species composition in fragments. Pp. 9-24 in Isolated vertebrate communities in the tropics (G. Rheinwald, ed.). Bonner Zoologische Monographen 46, Bonn, Germany, 400 pp. 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
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
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