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The discipline of sustainability science has emerged in response to concerns of natural and social scientists, policymakers, and lay people about whether the Earth can continue to support human population growth and economic prosperity. Yet, sustainability science has developed largely independently from and with little reference to key ecological principles that govern life on Earth. A macroecological perspective highlights three principles that should be integral to sustainability science: 1) physical conservation laws govern the flows of energy and materials between human systems and the environment, 2) smaller systems are connected by these flows to larger systems in which they are embedded, and 3) global constraints ultimately limit flows at smaller scales. Over the past few decades, decreasing per capita rates of consumption of petroleum, phosphate, agricultural land, fresh water, fish, and wood indicate that the growing human population has surpassed the capacity of the Earth to supply enough of these essential resources to sustain even the current population and level of socioeconomic development., Competing Interests: The authors have declared that no competing interests exist.

General statistical patterns in community ecology have attracted considerable recent debate. Difficulties in discriminating among mathematical models and the ecological mechanisms underlying them are likely related to a phenomenon first described by Frank Preston. He noted that the frequency distribution of abundances among species was uncannily similar to the Boltzmann distribution of kinetic energies among gas molecules and the Pareto distribution of incomes among wage earners. We provide additional examples to show that four different 'distributions of wealth' (species abundance distributions, species-area and species-time relations, and distance decay of compositional similarity) are not unique to ecology, but have analogues in other physical, geological, economic and cultural systems. Because these appear to be general statistical patterns characteristic of many complex dynamical systems they are likely not generated by uniquely ecological mechanistic processes.

The oxygen isotopic composition (δ 18 O) of land snail shells can be a valuable paleoenvironmental archive if the climatic parameters that influence the isotopic system are fully understood. Previous calibration studies have examined a limited number of species or individuals, and most have focused on larger (> 10 mm) taxa, which do not represent the dominant shell material in the Quaternary fossil record. In this study, we evaluate the δ 18 O values of small land snails (< 10 mm), which are common in modern settings and are often preserved in a wide array of Quaternary geologic and archeologic deposits. Our primary goal was to determine if coexisting species record equivalent isotopic information in their shells, regardless of differences in their ecology, dietary habits, behavior, and/or body size. We collected and analyzed 265 individuals of 11 species from 12 sites in northwest Minnesota (USA), which exhibits extremely abundant and diverse terrestrial malacofauna in North America. We did not observe significant correlations between shell δ 18 O values and the type of ecosystem (forest/grassland) or hydrologic setting (upland/lowland). However, the majority of species differed significantly in shell δ 18 O values. Larger taxa ( Catinella , Succinea , Discus ) consistently yielded higher δ 18 O values than smaller taxa ( Euconulus , Gastrocopta , Hawaiia , Vallonia ), by up to ~ 3‰. These isotopic offsets among sympatric taxa could be attributed to a number of physical, behavioral, and/or evolutionary traits, including the ability of larger species to tolerate drier conditions better than their smaller counterparts, differences in their preferred microhabitats or phylogentic non-independence. Regardless of the reason, our results imply that researchers should not combine isotopic data from different types of land snails without first investigating modern specimens to determine if it is appropriate. Moreover, our data suggest that combining instrumental climate data, a snail flux-balance model, and shell δ 18 O values can help us to better understand the ecology of land snails. [ABSTRACT FROM AUTHOR]

Ecologists often believe the discovery of mechanism to be the central goal of scientific research. While many macroecologists have inherited this view, to date they have been much more efficient at producing patterns than identifying their underlying processes. We discuss several possible attitudes for macroecologists to adopt in this context while also arguing that in fact macroecology already has many mechanisms that are ignored. We briefly describe six of these: central limit theorem, fractals, random sampling and placement, neutral theory (and descendents), concordance of forces, and maximum entropy. We explore why these mechanisms are overlooked and discuss whether they should be. We conclude that macroecology needs to take a more pragmatic, less ideological approach to mechanism. We apply this viewpoint to the recent controversy over maximum entropy and suggest that maximum entropy needs to be viewed more pragmatically and less ideologically. [ABSTRACT FROM AUTHOR]

One of the most frequently studied pattern in ecology is the Species Abundance Distribution (SAD) that represents the frequency distribution of species abundances in an assemblage. Two main approaches to displaying such information have been employed: histograms constructed using exponentially increasing bin widths as pioneered by Preston (), and plots of ranked species abundances. While both techniques have been extensively used in the investigation of community ecology hypotheses, the Preston-style species-abundance histogram has become central to current debates concerning appropriate characterization of the SAD and the processes generating it. Here we point out an important issue in the Preston approach that has profound implications to this debate: by employing bins of exponentially increasing size, the resultant histogram may display a hump-shaped pattern that is not congruent with the shape of the untransformed distribution. Moreover, any distribution constructed from log-transformed abundances will necessarily reveal at least one internal mode, even when the non-transformed probability density function is strictly decreasing. We warn against misinterpretation of such transformed datasets, and suggest that rank-abundance plots, which are equivalent to the cumulative distribution functions extensively used in other branches of science, represent a more informative approach as they allow for better discrimination between a number of probability distributions. Ecologists should be aware that logarithmic transformation often generates a log-normal-like shape, and are encouraged to use rank abundance curves to visualize and analyze species-abundance patterns. [ABSTRACT FROM AUTHOR]

Ecological explanations of the distributions of living things rest on two general conceptual pillars: the niche difference model and the model of spatial and temporal constraint. Both models suggest the underlying importance of spatial distance as a simple correlate of biological pattern. In this essay we discuss five key, but seemingly disparate, conservation issues that have some correlation with or basis in spatial distance. The realization that the world is, at some level, everywhere unique suggests that optimum nature reserve design must find a balance between protecting grain (habitat integrity) and extent (distance). The distance involved in biotic movements helps us define "exotic" and predict invasive risk. The effect of gene movements also has a strong distance correlate, with fitness potentially declining with distance moved (outbreeding depression). Failure to consider spatial variation in disturbance regimes, community composition, and genetic makeup of populations also may hinder restoration. The relevance of reference site information in general decreases as the distance between these sites and restoration areas increases. The distance paradigm we define suggests that there are two inherent bases to conservation: ecology and geography. [ABSTRACT FROM AUTHOR]