Most of accumulation curves tend to underestimate species richness, as they do not consider spatial heterogeneity in species distribution, or are structured to provide lower bound estimates and limited extrapolations. The total-species (T-S) curve allows extrapolations over large areas while taking into account spatial heterogeneity, making this estimator more prone to attempt upper bound estim...

Daily instantaneous natural mortality rates of marine pelagic fish eggs and larvae are higher than expected from the trend of mortality rate with dry weight in the sea. The difference between observed mortality rates and those predicted from the trend of mortality with dry weight is directly and positively correlated with the patchiness of their spatial distribution, which suggests that it is c...

Spatial and temporal variability of nitrogen fixation in Lake Valencia, Venezuela, were quantified on the basis of duplicate water samples collected from a depth of 0.5 m at 16 sites on 10 dates. The concentration of heterocysts in samples was determined and the samples were incubated with acetylene in situ. Two-way ANOVA was used to separate the variance associated with site (fixed spatial pat...

Phytoplankton patchiness ubiquitously observed in marine ecosystems is a simple physical phenomenon. Only two factors are required for its formation: one is persistent variations of inhomogeneous distributions in the phytoplankton population and the other is turbulent stirring by eddies. It is not necessary to assume continuous oscillations such as limit cycles for realization of the first fact...

Classical criticality describes sudden changes in the state of a system when underlying processes change slightly. At this transition, patchiness develops which lacks a characteristic or dominant spatial scale. Thus, criticality lies at the interface of two important subjects in ecology, threshold behavior and patchiness. Most ecological examples of criticality involve processes of disturbance ...

Plankton patchiness in homogeneous physical environments is studied in this paper assuming that all involved populations disperse diffusively. A recent but powerful sufficient condition for the emergence of spatial patterns in models with any number of species is systematically applied to all food chain and food web plankton models and the result is rather sharp: all models explicitly containin...

Many habitat specialist species are originally composed of small, discontinuous populations because their habitats are naturally fragmented or patchy. They may have suffered the long-term effects of natural patchiness. Mediterranean heathlands, a representative habitat in the Strait of Gibraltar region, are associated with nutrient-poor, acidic sandstone soils. Sandstone soil patches in the Afr...

Spatial patchiness and temporal variability in water availability are common in nature under global climate change, which can remarkably influence adaptive responses of clonal plants, i.e. clonal integration (translocating resources between connected ramets). However, little is known about the effects of spatial patchiness and temporal heterogeneity in water on growth and clonal integration bet...

The availabilities of light and soil water resources usually spatially co-vary in natural habitats, and the spatial pattern of such co-variation may affect the benefits of physiological integration between connected ramets of clonal plants. In a greenhouse experiment, we grew connected or disconnected ramet pairs [consisting of a proximal (relatively old) and a distal (relative young) ramet] of...