Restoring Farm Woodlands for Wildlife

Millions of hectares of temperate woodland and billions of trees have been cleared from Australia’s agricultural landscapes. This has allowed land to be developed for cropping and grazing livestock but has also had significant environmental impacts, including erosion, salinity and loss of native plant and animal species. Restoring Farm Woodlands for Wildlife focuses on why restoration is important and describes best practice approaches to restore farm woodlands for birds, mammals and reptiles. Based on 19 years of long-term research in temperate agricultural south-eastern Australia, this book addresses practical questions such as what, where and how much to plant, ways to manage plantings and how plantings change over time. It will be a key reference for farmers, natural resource management professionals and policy-makers concerned with revegetation and conservation.

Adult fecundity, host plant preferences, field activity and parasitism in the leaf weevil Phyllobius pyri (L.) (Coleoptera: Curculionidae)

Adults of the leaf weevil Phyllobius pyri (L.) (Coleoptera: Curculionidae) feed on a wide variety of broadleaved trees and occasionally cause severe defoliation in newly established farm woodlands. There is little information, however, on the relative susceptibility of different tree species to damage or on the habitat associations of adults and larvae of P. pyri, which might indicate the conditions that predispose trees to attack. Captures of adult P. pyri in emergence and flight traps in the current study indicated population densities in grassland of 0.5–6.4 adults per m2 at emergence but higher densities up to 13.5 per m2 in young pine plantations, where there was a mixture of grassy patches and young, naturally regenerating birch trees. The close proximity of larval food resources (grass roots) and a favoured adult host-plant, which also occurs in young farm woodlands, provided ideal conditions for P. pyri and allowed high population densities to develop. Feeding and performance experiments indicated that cherry, birch, oak and hornbeam were most susceptible to P. pyri, whereas field maple, hawthorn, rowan, lime and especially ash were resistant. Adult female P. pyri emerged in May reproductively immature and fed on tree foliage for 15.9±0.9 days before laying their first batch of eggs. Adults lived for 33.3±1.5 days, on average, and females laid a mean of 191.9±34.5 eggs (maximum=589) during their lifetime. Eggs hatched after 16–20 days. During 2003 and 2004, 11–16% of adult P. pyri were parasitised by Pygostylus falcatus (Hymenoptera: Braconidae) and 19–29% were parasitised by Rondania fasciata (Diptera: Tachinidae).

Potential for Ammonia Recapture by Farm Woodlands: Design and Application of a New Experimental Facility

There has been increasing pressure on farmers in Europe to reduce the emissions of ammonia from their land. Due to the current financial climate in which farmers have to operate, it is important to identify ammonia control measures that can be adopted with minimum cost. The planting of trees around farmland and buildings has been identified as a potentially effective and low-cost measure to enhance ammonia recapture at a farm level and reduce long-range atmospheric transport. This work assesses experimentally what fraction of ammonia farm woodlands could potentially remove from the atmosphere. We constructed an experimental facility in southern Scotland to simulate a woodland shelterbelt planted in proximity to a small poultry unit. By measuring horizontal and vertical ammonia concentration profiles within the woodland, and comparing this to the concentration of an inert tracer (SF6) we estimate the depletion of ammonia due to dry deposition to the woodland canopy. Together with measurements of mean ammonia concentrations and throughfall fluxes of nitrogen, this information is used to provide a first estimate of the fraction of emitted ammonia that is recaptured by the woodland canopy. Analysis of these data give a lower limit of recapture of emitted ammonia, at the experimental facility, of 3%. By careful design of shelterbelt woodlands this figure could be significantly higher.