Moose Alces alces habitat use at multiple temporal scales in a human-altered landscape

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Boom and bust of a moose population – a call for integrated forest management

This is the postprint version of the article. The published article can be located at www.springerlink.comThere is increasing pressure to manage forests for multiple objectives, including ecosystem services and biodiversity, alongside timber production. However, few forests are currently co-managed for timber and wildlife, despite potential economic and conservation benefits. We present empirical data from a commercial Norway spruce ( Picea abies ) and Scots pine ( Pinus sylvestris ) production system in southern Norway in which moose ( Alces alces ) are an important secondary product. Combining long-term hunting and forestry records, we identified temporal vari- ation in clear-felling over the past five decades, peaking in the 1970s. Herbicide treatment of regenerating stands and a fivefold increase in moose harvest has lead to a reduction in availability of successional forest per moose of [ 90 % since the 1960s. Field estimates showed that spraying with the herbicide glyphosate reduced forage availability by 60 and 96 % in summer and winter, respectively, 4 years after treatment. It also reduced moose use and habitat selection of young spruce stands compared with unsprayed stands. Together these lines of evidence suggest that forest man- agement led to an increase in moose carrying capacity during the 1970s and a subsequent decline thereafter. This is likely to have contributed to observed reductions in moose population productivity in southern Norway and is counter to sustainable resource management. We therefore call for better integration and long-term planning between forestry and wildlife management to minimise forest damage and the development of large fluctuations in ungulate populations

MOOSE AS A PROBLEM IN SWEDISH FORESTRY

Some of the problems arising from the relationship between moose and forestry are presented. Most moose habitats in Sweden are used for commercial forestry. One of the main species of Swedish forestry is Scots pine (Pinus sylvestris), which also is one of the main food species of the moose during the winter. The high moose utilization of pines will mean losses to forestry. Some investigations on moose damage surveys in pine plantations are presented. Air survey is compared to ground survey. Air survey can be used to evaluate the degree of damage. Moose sometimes break pine stems. The broken trees are mainly between 2 and 4 m, their breast height diameter 15-45 mm

Data from: Moose browsing alters tree diversity effects on birch growth and insect herbivory

Producer diversity is known to affect a wide range of ecosystem processes including plant growth and insect pest resistance. Consumers such as mammalian herbivores too have been shown to modify plant growth and insect herbivory by triggering changes in host plants. However, few studies have investigated whether consumer effects interact with plant species diversity effects on a focal plant. To unravel consumer-diversity interactions, we recorded both the presence and intensity of winter browsing by moose (Alces alces) on silver birch (Betula pendula) in a long-term forest diversity experiment in Finland and measured birch tree growth as well as insect chewing damage during the following growing season. Although browsing on birch by moose was not affected by tree species richness, the intensity of moose damage altered tree diversity effects on birch tree growth. At minor browsing intensity, tree height, trunk diameter and canopy projections showed positively-humped relationships with tree diversity, peaking at 3-species mixtures. Growth of moderately browsed trees increased with tree species richness, but growth of severely browsed birch trees was unaffected. Moose browsing also altered the direction of tree diversity effects on insect herbivory on birch. Unbrowsed trees experienced lower insect chewing damage in mixed stands (associational resistance) whilst browsed trees suffered more insect chewing damage in diverse stands (associational susceptibility). Increasing browsing intensity also reversed the relationship between tree species richness and insect chewing damage from negative to positive. The observed interactions between moose browsing and tree species richness effects could be explained by lower canopy cover of more diverse stands compared to birch monocultures, leading to increased re-growth capacity and more high-quality foliage of browsed birch trees in more open diverse stands. Our findings demonstrate that both the presence and intensity of mammalian browsing may modify the magnitude and even the direction of tree diversity effects on tree growth and susceptibility to insect herbivory. Differences in consumer impact among studies may thus potentially explain much of the observed variability in plant diversity effects on ecosystem functioning and must therefore be taken into account in future studies