Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

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West-slope forest of Usturoi Valley, part of Baia Mare Central Park.


Woody plantation of 1962-64, on Eastern slope of Valea Usturoi (Oriental Carpathians) have become in 50 years an urban forest, which completes the Central Park of Baia Mare (NW Romania), pleasing both local people and foresters through: * Harmonious mixt of 16 forest species (70% conifers and 30% broadleaves, respectively 55% indigenous and 45% exotics). * Outstanding thickness increment achieved (especially in optimum sites) by the exotics Pinus strobus (48.4 cm), Gleditsia triacanthos, and Juglans nigra, respectively Mediterranean Castanea sativa (from which only American white pine has also height high increment). * High heights (in optimal sites) achieved by the European conifers Larix decidua, Pinus sylvestris, and Picea abies (>30 m). * Good diameter growth of exotic conifers Thuja plicata and Tsuga canadensis (32.3-32.8 cm, close to European conifers 30.1-35.1 cm). * Good to moderate increment, comparing to the other species, for exotics Phellodendron amurense (30.5 cm), Catalpa speciosa (29.2 cm), Chamaecyparis lawsoniana (22.7-28.0 cm), and Prunus serotina (26.4 cm). * Very good sanitary state of the majority of tested species, except sweet chestnut (very high infected with Cryphonectria parasitica), Northern catalpa (which suffered by stem rot and crown thinning) and wild cherry (affected by drought), respectively stem top forking of the Canadian hemlock. * Original and charming landscape composed by different crown features of exotic or native conifers (compact narrow-pyramidal on giant arborvitae, large-pyramidal on Canadian hemlock, airy and light coloured on European larch, bluish pendent tops on Lawson cypress), variate leaf shapes (from largest leaves of catalpa to small shinny leaves of black cherry, and large-composed ones on black walnut), flower (from luxuriant white with reddish sketch on catalpa to optimistic white spring flowers of cherries), and bark (from corky of Amur cork tree, long striped on Lawson cypress, to smooth but thorny on honey locust) on broadleaves species. * Effervescence of local biodiversity - many invertebrates, amphibians, reptiles, birds, and mammals searching for food and shelter. * For achieving the optimal status of this urban forest, several tending operations, pest control, and enhancement have to be done: * Selective thinning and sanitary cuttings; * Biologic control of the sweet chestnut blight; * Arrangement of the access paths and belvedere/lookout points; * Settlement of information plates about the exotic and local forest species.