Local management or wider context: What determines the value of farm revegetation plantings for birds?

Abstract

1. Small-scale revegetation plantings on farms are common to restoration efforts in agricultural regions worldwide. Such plantings provide habitat for diverse faunal groups. A key question concerns the degree to which their value for biodiversity is influenced by the features of individual plantings, which can be controlled by local land managers, or by broader-scale drivers in the wider landscape.2. We developed a conceptual model of factors of potential influence on birds in revegetation plantings at different spatial scales. To test this model, we surveyed native birds in 133 plantings in south-eastern Australia. Regression models were used to compare the effect of 'habitat-', 'patch-', 'farm-' and 'landscape-' scale variables on species richness (of woodland and open country birds) and the occurrence of individual species in plantings. We further tested whether the influence of variables representing local actions was swamped by larger-scale variables.3. Birds that occupied plantings were influenced by variables at all scales. Woodland birds were consistently richer and more likely to use older plantings (patch scale) with higher floristic richness (habitat scale), and surrounded by more wooded vegetation (at patch, farm and landscape scales). Open country species responded positively to the density of live trees (habitat scale) and the presence of large remnant tree/s (patch scale) in plantings. Variables representing local management actions generally maintained a stronginfluence on birds in plantings irrespective of the influence of broader drivers. Few relationships between bird species and planting attributes were contingent on features of the surrounding landscape; those that were suggested woodland birds are more responsive to local actions when broad-scale vegetation cover is greater. Synthesis and applications.Land managers can enhance the conservation value of plantings by (a) planting a greater diversity of trees and shrubs and (b) locating revegetation near other vegetation or around mature remnant tree/s. These actions will measurably increase the value of plantings for birds, irrespective of larger-scale drivers. Nonetheless, the important role of increased vegetation cover across broader agricultural landscapes emphasises that the collective efforts of individuals and larger initiatives are critical for conservation.| 2553

Restoration promotes recovery of woodland birds in agricultural environments: A comparison of ‘revegetation’ and ‘remnant’ landscapes

“…Species in ‘revegetation’ landscapes were a subset of the regional avifauna; there was not a specialist suite that occur only in plantings. Further, at the level of individual plantings, both species richness and the occurrence of many individual species were positively influenced by the amount of nearby vegetation, at both local and broader scales (Haslem et al, 2021).…”

“…Plantings were a maximum of ~40 years old at the time of survey, and thus ‘revegetation’ landscapes primarily represented early to mid‐successional vegetation. Time since planting was a significant influence on species richness and the occurrence of many species in individual plantings (Haslem et al, 2021). The complementarity of remnants and plantings in ‘mixed’ landscapes, which together provide resources associated with older and younger vegetation, likely explains why woodland assemblages in these landscapes did not differ in richness or composition from those in ‘remnant’ landscapes.…”

“…In rural environments, scattered trees provide habitat for many species (Fischer & Lindenmayer, 2002; Haslem & Bennett, 2008) and function to ‘soften’ the landscape by acting as stepping stones for movement of birds and other taxa through otherwise‐cleared farmland (Doerr et al, 2011). Further, plantings sited around mature trees facilitate access to resources such as large trunk and bark surfaces, tree hollows and perching sites not available in young plantings; and enhance opportunities in planted sites for many species (Barrett et al, 2008; Haslem et al, 2021).…”

Temporal dynamics in the composition of bird communities along a gradient of farmland restoration

“…We tested whether revegetation was successful at restoring bird communities, such that assemblages in plantings diverged away from those in unrestored farmland and converged toward those in reference habitats. This builds on previous work that focused on the avifauna of revegetation sites specifically (Haslem et al, 2021), and complements other contributions examining the landscape‐scale benefits of restoration for birds (Bennett et al, 2022; Haslem, Maisey, et al, 2023). Here, we examine the following questions. Does the composition of bird communities at sites in revegetation differ from those in unrestored farmland (pasture, scattered paddock trees) and reference habitats (native vegetation)? Are bird communities in revegetation diverging away from those in unrestored farmland and converging toward those in reference habitats over time? …”

“…Many native bird species use plantings in farmland (Haslem et al, 2021; Lindenmayer et al, 2010; Paxton et al, 2018; Whytock et al, 2018), with species richness often recovering more rapidly than community composition (Catterall et al, 2012; Haslem, Maisey, et al, 2023). However measures of taxonomic composition offer important insights into the different types of species that use revegetation plantings, and how this changes over time.…”