The topics of succession and post-disturbance ecosystem recovery have a long and convoluted history. There is extensive redundancy within this body of theory, which has resulted in confusion, and the links among theories have not been adequately drawn. This review aims to distil the unique ideas from the array of theory related to ecosystem change in response to disturbance. This will help to reduce redundancy, and improve communication and understanding between researchers. We first outline the broad range of concepts that have developed over the past century to describe community change in response to disturbance. The body of work spans overlapping succession concepts presented by Clements in 1916, Egler in 1954, and Connell and Slatyer in 1977. Other theories describing community change include state and transition models, biological legacy theory, and the application of functional traits to predict responses to disturbance. Second, we identify areas of overlap of these theories, in addition to highlighting the conceptual and taxonomic limitations of each. In aligning each of these theories with one another, the limited scope and relative inflexibility of some theories becomes apparent, and redundancy becomes explicit. We identify a set of unique concepts to describe the range of mechanisms driving ecosystem responses to disturbance. We present a schematic model of our proposed synthesis which brings together the range of unique mechanisms that were identified in our review. The model describes five main mechanisms of transition away from a post-disturbance community: (i) pulse events with rapid state shifts; (ii) stochastic community drift; (iii) facilitation; (iv) competition; and (v) the influence of the initial composition of a post-disturbance community. In addition, stabilising processes such as biological legacies, inhibition or continuing disturbance may prevent a transition between community types. Integrating these six mechanisms with the functional trait approach is likely to improve the predictive capacity of disturbance theory. Finally, we complement our discussion of theory with a case study which emphasises that many post-disturbance theories apply simultaneously to the same ecosystem. Using the well-studied mountain ash (Eucalyptus regnans) forests of south-eastern Australia, we illustrate phenomena that align with six of the theories described in our model of rationalised disturbance theory. We encourage further work to improve our schematic model, increase coverage of disturbance-related theory, and to show how the model may link to, or integrate with, other domains of ecological theory.

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1. Managing agricultural landscapes for biodiversity conservation is increasingly difficult as land use is modified or intensified for production. Finding ways to mitigate the negative effects of agriculture on biodiversity is therefore critical. We asked the question: How do remnant patches, paddock types and grazing regimes influence reptile assemblages in a grazing landscape? Accepted ArticleThis article is protected by copyright. All rights reserved.2. At 12 sites, we surveyed reptiles and environmental covariates in remnant woodland patches and in four paddock types: a) grazed pasture, b) linear plantings, c) coarse woody debris added to grazed pasture and d) fences between grazed pasture. Each site was either continuously or rotationally grazed.3. Remnant vegetation and other vegetation attributes such as tree cover and leaf litter greatly influenced reptiles. We recorded higher reptile abundance and species richness in areas with more tree cover and leaf litter. For rare species (captured in ≤4 sites <70 captures) there were 5.7 more animals and 2.6 more species in sites with 50% woody cover within 3 km compared to 5% woody cover.4. The abundance and richness of rare species, and one common species differed between paddock types and were higher in linear plantings and fence transects compared to coarse woody debris and pasture transects. Synthesis and applications.Grazed paddocks, particularly those with key features such as fences and plantings can provide habitat for reptiles. This suggests that discrete differentiation between patch and matrix does not apply for reptiles in these systems.Management to promote reptile conservation in agricultural landscapes should involve protecting existing remnant vegetation, regardless of amount; and promote key habitat features of trees, leaf litter and shrubs. Establishing plantings and fences is important as they support high numbers of less common reptiles and may facilitate reptiles to move through and use greater amounts of the landscape.

Aim: Effective management of biodiversity in human-modified landscapes demands an understanding of how biotas respond to landscape features and management actions.Yet, biotic responses are complex and varied, resulting in numerous conceptual models being developed to aid interpretation and generalization. We examined the relevance of a range of conceptual landscape models that describe how the distribution of habitat influences species richness, abundance, occurrence and spatial dynamics, using an empirical data set of reptile and frog responses to agricultural management.Location: South-eastern New South Wales, Australia. Methods:We tested predictions developed from five conceptual landscape models using data collected from five land cover types and two grazing regimes.Results: At least one species responded in a manner consistent with each of the five conceptual models tested. Most species responded to gradients of environmental variables and species-specific responses were observed, in congruence with the Continuum model. No species were consistently congruent with predictions from concepts of Island Biogeography theory. One-third of responses were congruent with the Matrix Quality model. The main prediction tested from the Matrix Tolerance model was upheld by both reptile and frog species. The predictions of the Habitat Amount hypothesis were upheld by rare reptile abundance and richness, and one frog species. Main conclusions:Our study suggests that most conceptual models have some relevance to real-world systems and can be useful for interpreting biotic responses to landscape change and management. Importantly, no one model fully captured the range of species responses to our agricultural landscape, but the Continuum model, Matrix Quality model, Matrix Tolerance model and Habitat Amount hypothesis had complementary predictions that together appeared to explain most of the assemblage's responses to the management and environmental conditions of the agricultural landscape. K E Y W O R D S Continuum, habitat amount hypothesis, human-modified landscape, island biogeography theory, landscape ecology, matrix | 1409 PULSFORD et aL.

Summary Invasive species such as vertebrate herbivores cause threats to native ecosystems through causing changes to vegetation composition and structure, competition, ecosystem engineering, impacts on soil, and through spreading disease. In the mountainous country of Australia, Sambar Deer (Rusa unicolor) are becoming an increasing threat to fragile and endangered ecosystems, which are also facing other significant threats such as climate change. Methods for ameliorating these impacts are currently limited to lethal control programmes through shooting or fencing key areas. Fencing is not a viable option for large areas and can have large logistical costs as well as negative ecological outcomes. This study aimed to compare two shooting methods (ground shooting vs thermally assisted aerial culling with thermal image operator) for controlling sambar at low densities in a mountainous area. This programme was the first to use this specific thermal technique for deer in mountainous country in Australia. We found that thermally assisted aerial culling was more effective for removing Sambar than ground shooting. Thermally assisted aerial culling removed more Sambar in total, shot more animals per hour, covered a larger search area, was cheaper per hectare covered, and had very high “seen”, “targeted”, and “shot” ratios. Ground shooting sessions were lower in cost overall, but the cost per hectare was higher and rate of Sambar shot was lower than that of thermally assisted aerial culling. Ground shooting did remove more Sambar per hectare as ground shooting focuses on a smaller area, but this advantage is outweighed by the fact that thermally assisted shooting also allowed the concurrent removal of Feral Pigs. This work indicates that thermally assisted aerial culling is the preferred method for effective management of Sambar in an alpine environment. Ground shooting may be beneficial when Sambar are concentrated in key areas or to complement initial knock down by thermally assisted aerial culling.