Positive impacts on the ecology

Willow has been found to increase the biodiversity of an area over previous land uses, including sheep grazed pastures and arable crops where a low biodiversity predominates. Ecological studies of the large areas of SRWC planted in Yorkshire for the ARBRE project clearly demonstrated that willow plantations never displace species from an area and that the overall biodiversity, including ground vegetation, birds, butterflies and invertebrates, is improved (Rich and Sage, 2001).

Mammals: A minimum of 10 species have been observed in SRWC, including the Brown Hare, Stoat, Mice, Vole, Shrew, Fox and Rabbit. These include important food resources for larger carnivores.

Flora: 151 species of plant have been recorded growing in SRWC at sites across in England. These provide, both directly and indirectly, food for butterflies and many other insects and their predators. This diversity of ground flora is also important in regulating weed control by providing competition for resources and preventing domination of individual plant species. Floral diversity also increases the habitat complexity which will encourage a wider diversity of beneficial predatory invertebrates important for controlling pest species.

Birds: Due to the structural complexity of willow and the difference in morphology of the many varieties, at least 32 bird species have been recorded in SRWC. Arboreal species such as Tits and Warblers, ‘skulking’ species such as Wren and Robin, and migrant species also utilise the willow coppice. In west Wales, preliminary results from a study (by Llysdinam’s Wales Biomass Centre and IGER) using mist nets to evaluate the avian biodiversity of SRC recorded 14 species of birds within the cropped areas of first year SRC; and avifauna flocks of reed buntings (Emberiza schoeniclus) and finches were also observed.

Invertebrates: At least three times the number of plant-eating species spends part of their life cycle in the canopy of SRWC compared to conventionally grown barley and wheat (Sage & Tucker, 1998). Over 135 invertebrate species have been found in the canopies of willow, and almost as many ground dwelling and subterranean species have also been recorded. Between 70-80% of all of these species were found to be non-pest species and many of which were beneficial to the crop by predating on pests and therefore acting as a natural control.

Preliminary results from Welsh upland studies of SRWC have been encouraging and support the more general findings presented above. Evidence for upland Wales agrees with the lowland conclusions that the beneficial impacts of planting SRC greatly outweigh any negative ones and that these benefits can be enhanced through careful plantation design and sensitive management practices.

Negative impacts on the ecology:

The practice of growing SRC willow in monocultures, i.e. block planting of single varieties, poses high risk to rust as well as willow leaf beetle damage depending on the chosen variety. This could potentially lead to a dominance of a SRC willow habitat by a single pest species. Moreover, the spraying of crops with inappropriate insecticides can lead to non-target and beneficial insect damage, since most insecticides are not specific to their targets. However, in this case it is important to remember that planting guidelines recommend planting a thorough mixture of varieties and if done appropriately can prevent these problems.

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Lowthe-Thomas SC. Ground cover management for short rotation willow coppice in the uplands of mid-Wales. PhD Thesis. Cardiff: University of Wales (Cardiff University); 2003.

Rich TJ, Sage RB, Moore N, Robertson P, Aegerger J, Bishop J. ARBRE monitoring – ecology of short rotation coppice plantations. ETSU B/U1/00627/REP, DTI/Pub URN/ 01/768; 2001.

Sage R, Tucker K. Integrated crop management of SRC plantations to maximise crop value, wildlife benefits and other added value opportunities. ETSU B/W2/00400/REP; 1998.

Cardiff Scool of Biosciences.