Implications of transformation to irregular silviculture for woodland birds: A stand wise comparison in an English broadleaf woodland

Abstract

Woodland birds in Britain have undergone significant long term declines since the late 1960s, associated in particular with changes in woodland structure in general, and loss of early successional vegetation. Irregular, continuous canopy broadleaf management is a form of selective logging, very recently adopted in UK that produces woodlands with open canopies and substantial mid-and understorey growth. We examined spring and late winter bird densities, estimated using distance sampling, at 310 points in irregular, transitional (that being managed towards irregular), limited intervention, and coppice stands within a large working broad-leaf woodland in lowland southern Britain. Almost all understorey and canopy vegetation measures differed significantly across stand types. Ten of 20 species had highest spring abundance in irregular woodland, five in coppice, three in transitional, and just two in limited intervention. In winter, 5-6 species preferred each of limited intervention, irregular and transitional, while no species preferred coppice. Densities differed little across seasons except in Paridae where abundances increased in late winter during which limited intervention stands were used more by this group. Birds generally occupied similar niche positions and had similar niche breadths across seasons. Compared to under-managed woodlands, irregular silviculture in UK's broadleaf woodlands is likely to enhance habitat quality for woodland birds, including several species of conservation concern e.g. marsh tit Poecile palustris which was twice as abundant in irregular stands as in any other stand type.

Irregular silviculture positively influences multiple bat species in a lowland temperate broadleaf woodland

“…There is scattered mature and veteran whitebeam Sorbus aria, and more locally distributed beech Fagus sylvatica and sycamore Acer pseudoplatanus. There are a significant number of veteran trees, those identified as having biological and cultural importance (Read 2000); particularly of oak, ash and field maple and 19th Century beech Fagus sylvatica plantings (Alder et al 2018, Poore 2016.…”

“…Despite the potential of irregular management to support keystone species (Gustafsson et al 2020, there remains a significant knowledge gap of the effects on biodiversity following its introduction within temperate forests (Storch et al 2020). Recent research as part of our wider study has highlighted positive effects of irregular silviculture on woodland birds (Alder et al 2018).…”

“…At each sample plot measurements of woodland structure were collected within a 30 m diameter circle (0.07 ha) with five sub-plots of 3 m diameter within each (four located at the cardinal points at 10 m radii and one at 2 m off-centre along a random compass bearing (Alder et al 2018).…”

Overland flow velocity and soil properties in established semi‐natural woodland and wood pasture in an upland catchment

“…Woodlands with closed canopy cover will typically have sparse understorey vegetation (Alder et al, 2018), resulting in lower surface roughness and greater overland flow velocity. Mature semi‐natural woodlands with a varied age structure and canopy gaps, woody debris, shade‐tolerant woodland flora communities and greater understorey are likely to result in greater surface roughness and reduced overland flow.…”

“…Woodlands with closed canopy cover will typically have sparse understorey vegetation (Alder et al, 2018), resulting in lower surface…”