Scale is a concept that transcends disciplinary boundaries. In ecology and geography, scale is usually defined in terms of spatial and temporal dimensions. Sociological scale also incorporates space and time, but adds ideas about representation and organization. Although spatial and temporal location determine the context for social and ecological dynamics, social-ecological interactions can create dynamic feedback loops in which humans both influence and are influenced by ecosystem processes. We hypothesize that many of the problems encountered by societies in managing natural resources arise because of a mismatch between the scale of management and the scale(s) of the ecological processes being managed.We use examples from southern Africa and the southern United States to address four main questions: (1) What is a "scale mismatch?" (2) How are scale mismatches generated? (3) What are the consequences of scale mismatches? (4) How can scale mismatches be resolved? Scale mismatches occur when the scale of environmental variation and the scale of social organization in which the responsibility for management resides are aligned in such a way that one or more functions of the social-ecological system are disrupted, inefficiencies occur, and/or important components of the system are lost. They are generated by a wide range of social, ecological, and linked social-ecological processes. Mismatches between the scales of ecological processes and the institutions that are responsible for managing them can contribute to a decrease in social-ecological resilience, including the mismanagement of natural resources and a decrease in human well-being. Solutions to scale mismatches usually require institutional changes at more than one hierarchical level. Long-term solutions to scale mismatch problems will depend on social learning and the development of flexible institutions that can adjust and reorganize in response to changes in ecosystems. Further research is needed to improve our ability to diagnose, understand, and resolve scale mismatches in linked socialecological systems.

Standing crop biomass, energy expenditure and production by large mammalian herbivores in the African savannas show a high degree of correlation with mean annual precipitation and predicted above ground primary production. These relationships possess the potential for predicting carrying capacity and protein production from simple meteorological data.

Abstract. Protected areas (PAs) remain central to the conservation of biodiversity. Classical PAs were conceived as areas that would be set aside to maintain a natural state with minimal human influence. However, global environmental change and growing cross-scale anthropogenic influences mean that PAs can no longer be thought of as ecological islands that function independently of the broader social-ecological system in which they are located. For PAs to be resilient (and to contribute to broader social-ecological resilience), they must be able to adapt to changing social and ecological conditions over time in a way that supports the long-term persistence of populations, communities, and ecosystems of conservation concern. We extend Ostrom's social-ecological systems framework to consider the long-term persistence of PAs, as a form of land use embedded in social-ecological systems, with important crossscale feedbacks. Most notably, we highlight the cross-scale influences and feedbacks on PAs that exist from the local to the global scale, contextualizing PAs within multi-scale socialecological functional landscapes. Such functional landscapes are integral to understand and manage individual PAs for long-term sustainability. We illustrate our conceptual contribution with three case studies that highlight cross-scale feedbacks and social-ecological interactions in the functioning of PAs and in relation to regional resilience. Our analysis suggests that while ecological, economic, and social processes are often directly relevant to PAs at finer scales, at broader scales, the dominant processes that shape and alter PA resilience are primarily social and economic.

We tested the explanatory usefulness and policy relevance of Holling's (2001) "adaptive cycle" theory in exploring processes of "collapse," also called "release," and recovery in regional socialecological systems (SESs) in Zimbabwe and Australia. We found that the adaptive cycle is useful in recognizing changes in system behavior during the various phases. However, our small sample of cases did not generally show either the sequential passage of stages or the prerelease decline in resilience that adaptive cycle theory implies. In all cases, however, the reasons for releases were apparent with hindsight. On the other hand, our examples mostly supported the proposition that resilience is controlled by slowly changing variables. Although we found the adaptive cycle, and complex system theory in general, to be useful integrating frameworks, disciplinary theories are required to explain causes and effects in specific cases. We used theories linking distribution of political power to institutional change; to investment in natural, human, social, and physical capitals; and to access to financial capital. We explored patterns of change of these capitals before, during, and after release and reorganization. Both the patterns of change and relative importance of the different capitals during reorganization varied widely, but the importation of resources from broader scales was often a key to recovery. We propose that the resilience of most regional or national SESs can be explained in these terms. The capacity to self-organize emerged from our studies as a critical source of resilience. Although rebuilding this capacity at times requires access to external resources, excessive subsidization can reduce the capacity to self-organize. The policy implication is that cross-scale subsidization should end when self-organization becomes apparent, because subsidization can increase the vulnerability of the system as a whole. When the aim is to recover without changing the system fundamentally, the focus should be upon conserving or investing in the elements of capital critical for this. If the current system is not viable, it is necessary to invest in forms of capital that will enable fundamental change. It will also be necessary to stop investing in the capitals that maintained the unviable regime. The political difficulty of doing this is why SESs so often remain maladapted to current conditions and opportunities and eventually reach the point of collapse.

A wide range of bioenergetic, production, life history and ecological traits scale with body size in vertebrates. However, the consequences of differences in community body-size structure for ecological processes have not been explored. We studied the scaling relationships between body mass, shoulder height, hoof area, stride length and daily ranging distance in African ungulates ranging in size from the 5 kg dik-dik to the 5,000 kg African elephant, and the implications of these relationships on the area trampled by single and multispecies herbivore communities of differing structure. Hoof area, shoulder height and stride length were strongly correlated with body mass (Pearson's r >0.98, 0.95 and 0.90, respectively). Hoof area scaled linearly to body mass with a slope of unity, implying that the pressures exerted on the ground per unit area by a small antelope and an elephant are identical. Shoulder height and stride length scaled to body mass with similar slopes of 0.32 and 0.26, respectively; larger herbivores have relatively shorter legs and take relatively shorter steps than small herbivores, and so trample a greater area of ground per unit distance travelled. We compared several real and hypothetical single- and multi-species ungulate communities using exponents of between 0.1 and 0.5 for the body mass to daily ranging distance relationship and found that the estimated area trampled was greater in communities dominated by larger animals. The impacts of large herbivores are not limited to trampling. Questions about the ecological implications of community body-size structure for such variables as foraging and food intake, dung quality and deposition rates, methane production, and daily travelling distances remain clear research priorities.

Questions We investigated whether soils of small mounds resembled large mound or matrix soils, whether changes in plant composition reflected changes in soils, and the sequence in which plants colonize and disappear from mounds of increasing size. Location Miombo woodland in northwest Zimbabwe. Methods Macrotermitinae termitaria vary in size and soil nutrient concentrations, harbouring distinct woody plant assemblages, making them foci for plant and animal diversity, and also influencing primary, secondary and tertiary productivity. In spite of the importance of termitaria to heterogeneity and diversity, no studies have investigated changes in plant species assemblages as mound surface area increases to the point where mound vegetation is distinct from that of the matrix. We compared woody plant assemblages on 43 matrix plots with 95 Macrotermes termitaria across a range of surface areas, using ANOSIM, cluster analysis and MDS ordination. We compared soil nutrients, pH and clay, from ten large and ten small termitaria, and ten matrix sites. We also assessed how relative representation of large mound or matrix indicator species changed with mound area. Results Change was apparent even at mound sizes of >10 m2, where both soils and plant assemblages on mounds were significantly different to those of the matrix. Plant assemblages fell into two main groups at 20% similarity; the first comprised of matrix plots, mounds <10 m2 and some mounds between 10 and 30 m2; the second, the remainder of the mounds between 10 and 30 m2 and all mounds >30 m2. At 40% similarity, four groups emerged: matrix, mounds <10 m2, mounds 10–30 m2 and mounds >30 m2. Woody plant composition changed gradually as mound area increased. On termitaria <10 m2, only 25% of indicators were mound indicator species, but on mounds between 10 and 30 m2 in size, 62.5% were mound indicators. On termitaria >30 m2 in surface area, only mound indicator species were found. Conclusions Through termite activities in concentrating nutrients and clay, termitaria provide habitat for species usually excluded from the matrix. The process of mound building and the nature of the plants that establish on them seem to establish a positive feedback for establishment of other non‐woodland matrix species.

No abstract

No abstract