Using cattle for conservation objectives in a Scots pine Pinus sylvestris forest: results of two trials

Abstract

It has been argued that large ungulates play a key role in natural forest dynamics, but in Britain, the largest native ungulates (aurochs and elk) are extinct. Cattle could have some similar effects, and are widely used, but rarely tested, for nature conservation management. Here, we test conservation management with cattle at a native Scots pine Pinus sylvestris forest in Scotland. Our hypotheses were that cattle impacts would (a) increase the abundance of an understorey shrub of conservation importance, bilberry Vaccinium myrtillus; and (b) increase Scots pine seedling establishment. Two cattle trials were established, one for each objective, based on a 14-ha plot within the forest, and a 6.1-ha plot at the forest edge. Cattle were introduced for 2 months to both plots, giving an approximately 100-to 150-fold increase in ungulate biomass per hectare when compared to background deer abundance. The ground layer vegetation in both treatment and matched control plots was monitored before and after treatment, and subsequently over a 4-year period. At the within-forest trial, bilberry percent-cover, 4 years after treatment, was 1.9 times higher in the cattle area than in the control (95% confidence limits 1.6-2.3). Bilberry percentcover increases were directly related to the degree of trampling impact on heather Calluna vulgaris, as recorded immediately after the trial. At the forest-edge trial, there were vegetation changes in the cattle plot that were considered favourable to pine seedling establishment: reduced moss/litter depth and vegetation percent-cover, and increased ground-level light incidence. However, too few new pine seedlings were found for formal analysis, partly due to unexpectedly low seed-fall. Nevertheless, the potential for cattle to create conditions that would subsequently promote pine regeneration was illustrated by the observation of large numbers of new, young pine seedlings at the within-forest cattle plot. We recommend that managers and researchers collaborate to develop further trials like the ones reported here, to give an improved understanding of the conditions under which cattle can yield nature conservation benefits in woodlands.

Burning and mowing as habitat management for capercaillie Tetrao urogallus: An experimental test

“…This supports the argument that vegetation changes in plant communities are strongly linked to changes affecting the dominant species (Grime, 1998). We had similar results when investigating the effects of cattle grazing/ trampling on bilberry cover in similar vegetation (Hancock et al, 2010). Expressing cattle effects as a quantitative variable, in terms of heather impacts, rather than as a categorical treatment variable, gave a model with higher explanatory power (lower AIC C and cattle-effect P-value).…”

Experimental evidence from Cantabrian mountain heathlands suggests new recommendations for management of Vaccinium myrtillus L

“…Given the importance of Vaccinium for the conservation of endangered species (Storch 1993;Baines et al 1994;Rodríguez et al 2007), the cutting of Calluna to avoid competition and to promote diversity of vegetation has been recommended (Calvo et al 2007). In the same vein, Hancock et al (2010Hancock et al ( , 2011 found a consistent pattern of Vaccinium increase following Calluna loss, for a wide range of causes of Calluna loss (cattle trampling, burning, mowing or natural heather die-back) in open pinewoods, and they explained their results in terms of the 'dominance reduction' effect (Wohlgemuth et al 2002). However, this does not take into consideration that, according to the 'stress-gradient hypothesis', plant-plant interactions may range from negative to positive, depending on environmental conditions such as abiotic stress (Bertness and Callaway 1994;Maestre et al 2009).…”

Abandonment of traditional uses in mountain areas: typological thinking versus hard data in the Cantabrian Mountains (NW Spain)

“…Thus, cattle herding is not submitted to the carrying capacity of the ecosystem; its consideration as a traditional activity and a ''conservation asset'' (e.g. Hancock et al 2010) for other species seems highly questionable.…”