A new protocol for monitoring operational outcomes of environmental management in commercial forestry plantations.

Environmental degradation is a global phenomenon with a high likelihood of influencing human quality of life. Effective management responses are needed to achieve societal goals of sustainability. We develop here a new monitoring protocol (Management Check: MATCH) that comprehensively evaluates management outcomes at the operational level. Using the Driver-Pressure-State-Impact-Response (DPSIR) framework, we identified pressures influencing ecosystem integrity inside conservation corridors and commercial compartments of a timber production landscape mosaic. They were 1) domestic livestock grazing (the only exogenous pressure), 2) fire management, 3) invasive alien plants (IAPs), and potential soil erosion from two sources: 4) roads, and 5) harvested timber compartments. We assessed the effects of these on wetland and stream buffers. Environmental incidents accounted for more serious management issues (e.g. oil spills). Management responses were systematically unpacked into point-form questions, which formed the building blocks of our monitoring protocol. We assessed management in twelve plantations in KwaZulu-Natal, South Africa. Answers were compared with Best Operational Practice (BOP), and reworked into a Weighted Index of Compliance (WIC) per section. We found that there was poor management of livestock grazing, but good management of IAPs, roads, and timber compartments. Management of wetland and stream buffers was very good. Fire management presented problems linked to lack of direct effects, measurable at the spatial and temporal scales of operations. We discuss operational outcomes within their respective legislative frameworks, and suggest ways of improving management operations, where needed. MATCH is the first monitoring protocol to comprehensively assess environmental management of commercial forestry at the operational level, and to clearly translate operational activities into measurable progress towards strategic goals. In doing so, MATCH breaks down silos and builds bridges for efficient environmental management in dynamic socio-ecological systems. Moreover, the principles developed here can be applied to build tools that help manage major risks in other economic sectors too. Overall, MATCH strengthened strategic and informed action, which is necessary at multiple levels of an organization, to combat major societal risks, such as environmental degradation.

Congruence between arthropod and plant diversity in a biodiversity hotspot largely driven by underlying abiotic factors.

Plants often form the basis of conservation planning and management. The effectiveness of plant diversity as a surrogate for arthropod diversity was assessed in natural areas in the Kogelberg Biosphere Reserve, a floral endemism hotspot in the Cape Floristic Region (CFR), South Africa. Arthropods and plants were sampled across 30 topographically heterogeneous sites in a spatially nested design. The relationship between plants and arthropods were quantified in terms of species richness, assemblage variation, and assemblage turnover. The influence of arthropod trophic groups, habitat association, and spatial scale were also explored. Generalized dissimilarity modelling was used to investigate differential influence of explanatory groups (geology, disturbance, local site characteristics, refuge, mesoclimate, terrain) on arthropod and plant turnover. Congruence in assemblage variation was restricted to local scales, and only present between plants and those arthropods associated with the foliar component of the habitat. Weak congruence in species turnover was due to differences in the relative importance of explanatory groups, with different variables within each explanatory group being important, and similar variables predicting different turnover patterns. For both groups, variables related to geology and fire history were important for assemblage turnover. These variables are already incorporated in conservation planning and management for plant diversity across the CFR. Overall plant diversity was a weak surrogate for the arthropod groups included in this study, suggesting that as an alternative, environmental surrogates for arthropod diversity perform better.

Well-managed grassland heterogeneity promotes butterfly conservation in a corridor network.

Habitat degradation is a major concern in transformed landscapes, as it reduces complexity by removing species, interactions, and ultimately biodiversity. Degradation is also of concern for ecological networks (ENs) composed of an interconnected system of conservation corridors among South Africa's commercial forestry compartments. These corridors are predominantly grasslands, and used as rangeland, so managed to optimize grazing conditions. Yet, how this management approach influences biodiversity remains unknown. Here, we studied how butterfly assemblages respond to local differences in rangeland quality (low, high and reference sites), and how this effect compared to that of local environmental variables (e.g. rockiness and bare ground), meso environmental gradients (e.g. topographic position and aspect), and landscape composition (i.e. proportion of different land cover types in the surrounding matrix). We calculated species richness and composition, Shannon's diversity index (H'), and the Butterfly Conservation Index (BCIn) representing the proportion of sensitive and range-restricted butterfly species per site. Rangeland quality was considered less important for butterflies than other environmental variables, but it was also significantly confounded with other environmental variables. At the landscape scale, proportion of grassland in the landscape matrix influenced butterfly assemblage composition, while proportion of thicket had a significant positive effect on BCIn. Moreover, the effect of elevation on assemblage composition emphasizes the value of maintaining environmental gradients within these conservation corridors. At the meso spatial scale, butterfly species richness and diversity (H') declined with increased dominance by a single plant species, which usually occurs late in a normal fire cycle. This suggests a reliance by butterflies on recurring natural disturbances for long-term persistence. We recommend moderate patch burning and grazing, as well as occasional hot burns to reduce thicket in Afromontane grassland. This approach would improve local scale vegetation patterns, and increase heterogeneity across the landscape for conserving these butterflies into the future.

Precision control of an invasive ant on an ecologically sensitive tropical island: a principle with wide applicability.

Effective management of invasive ants is an important priority for many conservation programs but can be difficult to achieve, especially within ecologically sensitive habitats. This study assesses the efficacy and nontarget risk of a precision ant baiting method aiming to reduce a population of the invasive big-headed ant Pheidole megacephala on a tropical island of great conservation value. Area-wide application of a formicidal bait, delivered in bait stations, resulted in the rapid decline of 8 ha of P. megacephala. Effective suppression remained throughout the succeeding 11-month monitoring period. We detected no negative effects of baiting on nontarget arthropods. Indeed, species richness of nontarget ants and abundance of other soil-surface arthropods increased significantly after P. megacephala suppression. This bait station method minimized bait exposure to nontarget organisms and was cost effective and adaptable to target species density. However, it was only effective over short distances and required thorough bait placement. This method would therefore be most appropriate for localized P. megacephala infestations where the prevention of nontarget impacts is essential. The methodology used here would be applicable to other sensitive tropical environments.

Environmental filtering and spillover explain multi-species edge responses across agricultural boundaries in a biosphere reserve.

To ensure integrity of protected areas we need to understand how species respond to anthropogenic borders. We investigate, from a metacommunity perspective, the direct and indirect mechanisms by which transformed areas affect distribution patterns of ground-living arthropod assemblages inhabiting an extensive protected area adjacent to fruit orchards in an important biosphere reserve. Arthropods and environmental variables were sampled along transects perpendicular to natural-orchard edges. Influence of distance from orchard boundary, degree of impermeability of the boundary, orchard habitat quality (local scale land-use intensity), and edge-induced changes in local environmental variables on arthropod species richness and composition in non-crop habitats were assessed. Arthropod groups were assessed in terms of habitat fidelity: species associated with natural habitat (stenotopic species), those within crop habitat (cultural species), and those showing no preference for either habitat (ubiquitous species). Spillover resulted in higher cultural species richness near edges, but not higher overall species richness. Environmental filtering was important for stenotopic species composition, which was influenced by edge-induced changes in environmental variables. Ubiquitous species composition was determined by orchard impermeability. Increased orchard habitat quality was associated with higher cultural and ubiquitous species richness. The effects of orchards on assemblages in natural habitats can be variable, but predictable when using species habitat specificity in conjunction with a metacommunity framework. High intensity orchards may act as sink habitats, especially for species that readily disperse between crop and natural habitats. Here we recommend that local buffer strips are > 85 m wide, which will reduce the influence of cultural species spillover on sensitive natural ecosystems.

Feeding and Mobility Traits Influence Grasshopper Vulnerability to Agricultural Production in the Cape Floristic Region Biodiversity Hotspot.

To be able to foretell which species will be at risk of extinction from possible expansion of agriculture into natural areas, we need to determine how land use affects animal groups especially insects with different life history traits. Intuitively, we can predict that the proportion of specialist versus generalist grasshoppers and widespread versus localised species can be an indicator of change in vegetation patterns in a landscape. As a result, the study examined the relationship between the extent of range distribution and mobility of grasshoppers and land-use type in the Cape Floristic Region (CFR) biodiversity hotspot. It aimed at examining grasshopper assemblage composition in association with different land uses. We specifically related the number and type of sites occupied by grasshopper species to their mobility and distribution type to find out which characters improve species survival under highly modified habitats. Grasshopper assemblages were dominated by highly mobile generalists that tolerated transformed landscapes, and mostly geographically widespread. This contrasts with the low- to medium-mobile, range-restricted specialists, which make up close to 30% of the total collection, with a lower tolerance for anthropogenically modified landscapes in the CFR. This study also reveal that the fynbos biome is an important habitat for low-mobility and range-restricted species, and hence require conscious conservation efforts to conserve such species to prevent possible future biotic erosion and homogenisation in this hotspot. This result can be used to assess the possible extent of biotic erosion or otherwise in order to recommend better conservation efforts in the CFR.

Species temporal variability: epigaeic ant assemblages and management for abundance and scarcity.

Ant assemblages in five closely-spaced point habitats were studied over a three-year period in a subtropical area of South Africa. A total of 20,746 individuals in 56 species were sampled with pitfall traps. Rapid species turnover occurred during short periods after longer intervals of relatively constant species composition. There was annual cycling of total numbers of individuals. The temporal variance for total number of individuals within each habitat increased significantly with mean population size by a logarithmic regression. This indicates that population fluctuations are dependent upon the mean, with a distinctive relationship. The total number of species was cyclical, with annual and approximately half-yearly cycles. Each habitat nevertheless carried a characteristic mean number of species. The temporal variance of species richness showed a highly significant positive logarithmic relationship with the mean number of species. Pheidole megacephala (F.) accounted for 45% of all individuals. Its overall population showed annual cycles. Ph. megacephala population trend was the main determinant for seasonal variation of the whole assemblage in most habitats. Percentage dominance was positively linearly correlated with the variance and with mean population level. Although Ph. megacephala population variance increased with the mean, proportionate variability did not, indicating that high populations are no more variable than low populations. Five variability measures were compared with each other on ant assemblages containing only the common species (1st quartile) and then including the increasingly rare species (1st and 2nd, 1st, 2nd and 3rd, and all quartiles). Williamson's Variability Measure, using logarithmic or inverse sine transformations, gave variable results depending whether or not the rarer species were included in the analysis. The Coefficient of Fluctuation also gave variable results depending on assemblage size. The Coefficient of Variation and Proportionate Variability Measure gave similar and consistent results, indicating that common species are not more variable than rare ones. The rarer species are stenotopic and tend always to be rare, whereas the common species are eurytopic, highly competitive and demographically volatile. Control measures for common ants, and conservation of rare ants, should take cognizance of these trends.