Interactive effects of land use, grazing and environment on frogs in an agricultural landscape
- Authors: Pulsford, Stephanie , Barton, Philip , Driscoll, Don , Lindenmayer, David
- Date: 2019
- Type: Text , Journal article
- Relation: Agriculture, Ecosystems and Environment Vol. 281, no. (2019), p. 25-34
- Full Text: false
- Reviewed:
- Description: Improved management of human-modified landscapes must be part of global efforts to combat biodiversity loss. We aimed to identify which land management types and environmental factors influenced the use of grazing landscapes by frogs. We surveyed frog assemblages in remnant vegetation, four different paddock types (pasture, linear planting, coarse woody debris addition and fence), and two grazing regimes (continuous and rotational). Frogs were surveyed using pitfall and funnel traps in twelve grazing farms in south-eastern Australia. We found that grazed agricultural landscapes provide important habitats for a variety of species of frogs and that frog assemblages were influenced by both farm management type and environmental variables, and their interactions. Total frog abundance increased with proximity to water more strongly in remnants compared to paddocks. This difference in response may be due to different traits and behaviours of frogs in remnants compared to frogs in open paddocks. Rare frog species richness and abundance of a common species (Limnodynastes tasmaniensis) increased with taller ground cover in remnants but no such relationship occurred in paddocks. Different types of predation risk in remnants compared to paddocks may result in greater ground cover shelter requirements in remnants, as vegetation structure can strongly influence predation. Total frog species richness increased more rapidly with higher rainfall in continuously grazed versus rotationally grazed farms. Higher rainfall was associated with taller ground cover. Continuously grazed farms had shorter average ground cover than rotationally grazed farms and the increased ground cover height associated with more rain may bring ground cover to a height better able to provide shelter and reduce desiccation risk for frogs. Our study highlights the importance of both land management practices and environmental conditions and their interaction in shaping frog assemblages. Improved frog biodiversity conservation may be achieved in grazing landscapes by retaining patches of remnant vegetation, maintaining water bodies such as farm dams, and maintaining tall ground cover within vegetation remnants. © 2019 Elsevier B.V.
Beetle’s responses to edges in fragmented landscapes are driven by adjacent farmland use, season and cross-habitat movement
- Authors: Ng, Katherine , Barton, Philip , Macfadyen, Sarina , Lindenmayer, David , Driscoll, Don
- Date: 2018
- Type: Text , Journal article
- Relation: Landscape Ecology Vol. 33, no. 1 (2018), p. 109-125
- Full Text: false
- Reviewed:
- Description: Context: Farming practices influence the degree of contrast between adjoining habitats, with consequences for biodiversity and species movement. Little is known, however, on insect community responses to different kinds of edges over time, and the extent of cross-habitat movement in agricultural landscapes. Objective: To determine temporal changes in beetle responses to different farmland-woodland edges, and document cross-habitat movement. Methods: We examined species richness, abundance, and movement across edges between remnant woodlands and four farmland uses (plantings, fallow, annual crops, woody debris applied over crops post-harvest) in southeastern Australia. We used directional pitfall traps to infer movement, and sampled at edges, and 20 and 200 m on both sides of edges, during spring and summer. Results: Detritivore and predator abundance varied between seasons across the edge between woodlands and all farmlands, but seasonal differences were weaker for fallow-woodland and woody debris-woodland edges. Detritivores moved from farmlands towards woodlands, but not across fallow-woodlands and woody debris-woodlands edges during summer. During summer, predators showed short-range movement towards edges from all farmlands except plantings, and towards woody debris from woodlands. Edges showed temporally stable predator richness and higher herbivore richness than adjoining habitats. Conclusions: Farmland use and season interactively affect beetle abundance across farmland-woodland edges. Woody debris can reduce seasonal fluctuations in beetle edge responses and increase permeability for cross-habitat movement, while plantings provide habitat during summer. Edges provide important resources for beetles in adjoining habitats, however, seasonal movement of predators specifically into edges may affect prey assemblages—a link requiring further study. © 2017, Springer Science+Business Media B.V.
Reptiles and frogs use most land cover types as habitat in a fine-grained agricultural landscape
- Authors: Pulsford, Stephanie , Barton, Philip , Driscoll, Don , Kay, Geoffrey , Lindenmayer, David
- Date: 2018
- Type: Text , Journal article
- Relation: Austral Ecology Vol. 43, no. 5 (2018), p. 502-513
- Full Text: false
- Reviewed:
- Description: Agricultural landscapes comprise much of the earth's terrestrial surface. However, knowledge about how animals use and move through these landscapes is limited, especially for small and cryptic taxa, such as reptiles and amphibians. We aimed to understand the influence of land use on reptile and frog movement in a fine-grained grazing landscape. We surveyed reptiles and frogs using pitfall and funnel traps in transects located in five land use types: 1) woodland remnants, 2) grazed pastures, 3) coarse woody debris added to grazed pastures, 4) fences in grazed pastures and 5) linear plantings within grazed pastures. We found that the different land cover types influenced the types and distances moved by different species and groups of species. Reptiles moved both within, and out of, grazed paddocks more than they did in woodland remnants. In contrast, frogs exhibited varying movement behaviours. The smooth toadlet (Uperoleia laevigata) moved more often and longer distances within remnants than within paddocks. The spotted marsh frog (Limnodynastes tasmaniensis) moved out of grazed pastures more than out of pastures with coarse woody debris added or fences and were never recaptured in plantings. We found that most recaptured reptiles and frogs (76.3%) did not move between trapping arrays, which added to evidence that they perceived most of the land cover types as habitat. We suggest that even simple fences may provide conduits for movement in the agricultural landscape for frogs. Otherwise, most reptile and frog species used all land cover types as habitat, though of varying quality. Reptiles appeared to perceive the woodland remnants as the highest quality habitat. This landscape is fine-grained which may facilitate movement and persistence due to high heterogeneity in vegetation cover over short distances. Therefore, intensification and increasing the size of human land use may have negative impacts on these taxa. © 2018 Ecological Society of Australia