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ABSTRACT: Questions: What is the impact on non-target species of restoration methods to establish Calluna vulgaris on grass-dominated moorlands?Location: A Nardus stricta-dominated moorland in Wales and a Molinia caerulea-dominated moorland in Northern England, UK.Methods: Two replicated experiments were established on grass-dominated moorlands. The treatments comprised disturbance (rotavation and trampling by animals), addition of Calluna seed, and three different grazing regimes, together with a no grazing control.Results: The creation of bare ground and addition of seed increased the establishment of the desired dominant shrub, Calluna vulgaris. In the Nardus sward, rotavation and trampling were equally successful in establishing Calluna, but rotavation was more successful in the Molinia sward. Rotavation inhibited the growth of competitive grass species better than trampling. However, the disturbance techniques were detrimental to other components of the plant community, causing a decline in the cover of desirable species such as Vaccinium myrtillus and other dwarf shrub species and a small increase in the occurrence of undesirable species such as Juncus effusus. Grazing also controlled competitive grass species: Festuca ovina decreased in cover at a grazing intensity of 1.5 ewes/ha; Molinia caerulea and Agrostis spp. declined when cattle were included in the grazing regime, but increased in cover when ungrazed or when grazed at 1.5 ewes/ha.Conclusions: When restoration concentrates on the establishment of one or a few species, it is important to monitor how the techniques used affect the rest of the plant community – particularly with regard to losses of desirable species or increases in undesirable species.
Applied Vegetation Science 02/2009; 12(1):81 - 91. · 1.68 Impact Factor
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ABSTRACT: The spatial relationship between the concentration and deposition of the major ions in precipitation and stemflow and their influence on the tissue nitrogen concentration of three epiphytic bryophytes on Quercus petraea (Matt) Liebl. and Q. robur L. was investigated at seven UK Atlantic oak woodland sites with a range of total N deposition of 55-250 mmol m(-2). The main driver of change in tissue N concentrations of three epiphytic bryophytes (Isothecium myosuroides Brid. (Eurhynchium myosuroides (Brid.) Schp.), Dicranum scoparium Hewd. and Thuidium tamariscinum (Hewd.) Schimp.) was total N deposition in stemflow, dominated by ammonium deposition. The three epiphytic species also showed strong relationships between tissue N concentration and total N deposition in rainfall but a poor correlation with total N ion concentration in rainfall. This study shows that epiphytic bryophytes utilise stemflow N and thus increase their risk from inputs of total N deposition compared to terricolous species at the same site.
Environmental pollution (Barking, Essex: 1987) 04/2008; 155(2):237-46. · 3.43 Impact Factor
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Journal of Ecology 01/2005; 93(3):482 - 492. · 4.69 Impact Factor
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Functional Ecology 05/2004; 18(3):322 - 329. · 4.57 Impact Factor
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ABSTRACT: Many Atlantic oakwoods on the west coast of Scotland were cleared or under-planted with conifers, particularly Sitka spruce during the second half of the 20th century, resulting in a loss of habitat of high conservation value. Many of these conifer stands have been felled recently, or will be in the near future, providing an opportunity for the restoration of oak woodlands, a priority under the UK Habitat Action Plan for Upland Oakwoods.Trials were conducted to assess methods applicable to the restoration and expansion of Atlantic oakwoods with particular reference to areas cleared of conifers. The growth, browsing incidence and survival of planted oak seedlings was studied in three habitats: (1) birch woodland, (2) oak woodland and (3) felled conifer plantations (with additional treatments of fencing and brash removal) over a 2-year period.The browsing incidence was higher for seedlings in clear-felled areas than under adjacent oak and birch canopies during the first growing season. In the clear-felled areas, brash left in lines after felling protected seedlings against browsing by herbivores, with the depth of brash affecting the probability of browsing. However, survivorship and performance over 2 years was lower for seedlings planted in the brash than for seedlings planted in the clear area between brash lines.Seedlings planted under the oak canopy were defoliated more than those in the clear-felled areas or under the birch canopy. Possible mechanisms that affect seedling survival and performance such as the recolonisation of the ground flora in the clear-felled areas are discussed with management recommendations given.
Forest Ecology and Management 193(3):335-343. · 2.49 Impact Factor
