Abstract
<jats:p>Based on tree level data from engineering environmental surveys at 9 construction sites in four Russian cities (Ufa, Dmitrov, Moscow, Birobidzhan), the distribution of invasive woody plant species was analyzed. A total of 27,418 trees of 57 species were recorded. The proportion of invasive species ranged from 0 % in Birobidzhan to 46.8 % in Moscow. The absolute dominant among invasives is Acer negundo L. (5,751 individuals, 21 % of all trees). Regression analysis of the log transformed compensation cost (calculated according to regional regulatory documents) showed that, all else being equal (diameter, height, condition, city), invasive trees have, on average, a 9.9 % lower cost (p < 0.001), which is explained by the reduced species coefficients for box elder maple already embedded in the existing valuation methods. However, this reduction is insufficient to cover the costs of subsequent invasion control and monitoring. For A. negundo L., significant inter city differences were found: the highest proportion (9.9 % of all trees) and the lowest average cost (1,106 RUB) were recorded in Ufa, due to a high number of small diameter individuals on disturbed lands. In Moscow and Dmitrov, despite lower proportions, the average cost of invasive trees is much higher (6,836 and 6,085 RUB, respectively) due to larger tree sizes and better condition. Invasive herbaceous species (Heracleum sosnowskyi Manden., Solidago canadensis L., Ambrosia artemisiifolia L., etc.) were also recorded at the survey sites, requiring special attention during post project monitoring. We propose changes to the regulatory framework: introduction of an additional reduction factor (0.1–0.3) for invasive species when calculating compensation costs, mandatory inclusion of post project monitoring (at least 5 years) with removal of invasive seedlings, and priority use of native fast growing species in compensatory plantings on reclaimed sites.</jats:p>