An approach to predicting the potential forest composition and disturbance regime for a highly modified landscape: a pilot study of Strathdon in the Scottish Highlands

Abstract

Ray, D.2002. An approach to predicting the potential forest composition and disturbance regime for a highly modifi ed landscape: a pilot study of Strathdon in the Scottish Highlands. Silva Fennica 36(1): 233-247.The existing native forests of Scotland are fragmented and highly modifi ed and none are 'natural'. There is considerable interest in expanding the area of this oceanic boreal forest and restoring forest habitat networks to benefi t biodiversity. However, unlike regions with substantial remaining natural forest, it is diffi cult to provide reference values for forest composition and structure using methods related to historical variability. An alternative approach is to combine models that predict woodland type from knowledge of site conditions, and disturbance regime from knowledge of the disturbance agents (particularly abiotic agents).The applicability of this approach was examined as part of a public participatory planning exercise in a highly managed landscape in Eastern Scotland. Models of site suitability (Ecological Site Classifi cation) and wind disturbance (ForestGALES) were combined to determine potential woodland composition and structure, and derive options for native woodland expansion. The land use of the upper Strathdon catchment is currently dominated by agriculture and planted forests of non-native species, and only small fragments of semi-natural woodland remain (< 0.5% of the land area). Model results indicated that a very substantial proportion of the land area could support woodland (> 90%) but of a restricted range of native woodland types, with Scots pine communities predominant. Structural types likely to be present included wind-induced krummholz (treeline) forest, forest with frequent stand replacement by wind, and also a large area where gap phase (or some other disturbance) would predominate. The merits of the approach are discussed, together with the diffi culties of validation, and the implications for the management of existing forests.

An evaluation of Scottish woodland grant schemes using site suitability modelling

“…Many priority areas for forestry, notably the Scottish Highlands (Towers et al, 2006), experience cold annual temperatures, high precipitation, and strong winds (Mayes and Wheeler, 2013). Furthermore, basing species selection on existing woodland communities is often impossible due to a legacy of intensive land use that has heavily modified vegetation communities (Barnes and Pregitzer, 1982;Ennos et al, 1998;Quine et al, 2002). Site assessment is aided by land designation and local Forest and Woodland Strategies, which indicate priority areas for forestry based on site suitability, existing land use and community impacts, among other factors (FCS, 2010).…”

Towards a research agenda for woodland expansion in Scotland

“…For example, sustained burning and overgrazing in areas of the Scottish Highlands have led to soil degradation and an absence of local seed sources (Kinako and Gimingham, 1980;Quine et al, 2002). Benefits are also shaped by economic and social factors such as public or market access.…”

Rapid responses to facilitate ecological discoveries from major disturbances

“…2003). Similarly, early successional habitats within forests regenerating after wind‐storms or other disturbances can be important for a range of biota, including bryophytes (Quine et al . 2002), vascular plants (eg the pin cherry [Prunus pensylvanica] in the northern hardwood forests of the US; Marks 1974), and the goshawk (Accipter gentilis) in the UK (Petty 1996).…”