Nested subset analysis and taxa-range size distributions of pedological assemblages: implications for biodiversity studies

Toward a Theory of Island Pedogeography: Testing the driving forces for pedological assemblages in archipelagos of different origins

“…Higher relief implies more diversified altitudinal catenas and thus more variability of soil forming factors. The geology and Quaternary deposits are negatively correlated with island age (Table 3) whereas it is generally agreed that on older islands Quaternary deposits, landforms and weathering processes have had more time to be developed (Ibáñez et al, 2005b). Even though Quaternary richness and litho-richness are two variables best correlated with area, the counter trend here with age is believed due to erratic and disruptive volcanic activity.…”

“…In contrast, the leptosolitation index shows that small islands have less well developed soil cover than the larger ones. Ibáñez et al (2005b) noted that small isles are nested subsets of higher ones; that is, larger islands have more physiographic heterogeneities than small ones and have higher relief. As relief increases, altitudinal catenas in mountain ranges have more climatic types and so have more variability of soil forming factors (relief, organisms and climates), thus soil assemblages are more diverse on larger islands.…”

Methods to quantify the pedodiversity of 1 km2 areas — results from southern African drylands

“…They found similar conformity to a power law as the ecological literature predicts for diversity-area relationships in terms of island biogeography theory (MacArthur and Wilson, 1967;Rosenzweig, 1995). Further applications of ecological methods were prepared by Ibáñez et al (2005b) for nested subset analyses of pedological assemblages. They showed that nested patterns of soils and soil assemblages at different scales could be described similarly to regularities in biotic assemblages.…”

“…On these scales, abiotic environmental heterogeneity is assumed the most important driver for species richness and patterns besides population interaction (Gaston, 1996). The main reason for this high value of soil information is that within the range of abiotic environmental factors, soils or pedodiversity (PD) indices are the best single predictor of habitat heterogeneity, as they reflect the influence of many environmental factors (Ibáñez, 2005b).…”

Complex structure of pollinator-plant interaction-webs: random, nested, with gradients or modules?

“…For this purpose, a presence-absence matrix is established, with bee species aligned in columns (called "species") and plant species in rows (called "islands"). Many studies use NTC as "ideally suited to explore various features of nestedness" and hence used as the basis for far-reaching conclusions from the assumed nestedness (e.g., Ibáñez et al, 2005).…”