Abstract. This paper summarizes how the partisan influence literature assesses the relationship between the left-right party composition of government and policy outputs through a meta-analysis of 693 parameter estimates of the party-policy relationship published in 43 empirical studies. Based on a simplified 'combined tests' meta-analytic technique, we show that the average correlation between the party composition of government and policy outputs is not significantly different from zero. A mutivariate logistic regression analysis examines how support for partisan theory is affected by a subset of mediating factors that can be applied to all the estimates under review. The analysis demonstrates that there are clearly identifiable conditions under which the probability of support for partisan theory can be substantially increased. We conclude that further research is needed on institutional and socio-economic determinants of public policy.

Logging is considered the most important threat to species in boreal forests. In contrast to eastern Canada, where most boreal forests remain largely untouched, in Fennoscandia it is possible to assess the cumulative, long-term effects of intensive forestry on wildlife. But harvesting of stands is rapidly changing Canadian boreal forests, which represent an important proportion of the world's boreal forests. We show that Fennoscandia and eastern Canada present striking similarities in terms of forest-age structure, natural-disturbance regime, and structure of bird assemblages, and we provide an assessment of the long-term effects of forestry on eastern Canadian birds of the boreal forest. We used life-history traits from habitat, nesting site, and geographical range to calculate an index of sensitivity to changes induced by modern forestry for boreal species of each region. Tropical migrants commonly found in eastern Canadian boreal forests have life-history traits that are not threat factors in relation to changes caused by modern forestry. Therefore, the general belief that tropical migrants in North America are more sensitive to landscape changes than those in Europe may not hold for species found in the boreal coniferous forests of eastern Canada. Nine Fennoscandian species present high levels of sensitivity, and at least eight eastern Canadian species are of similar concern. In both regions, most of the sensitive species are resident cavity nesters. Given the important similarities between the two regions, the northern expansion of commercial forestry in eastern Canada is likely to result in the significant decline of several resident species, as has occurred in Fennoscandia. Efectos a LargoPlazo de Actividades Forestales sobre Aves de los Bosques Boreales Canadienses del Este: una Comparación con Fennoscandia Conservation Biology Volume 15, No. 4, August 2001presentan altos niveles de sensibilidad, mientras que por lo menos ochos especies del este de Canadá son de interés similar. En ambas regiones, la mayoría de las especies sensitivas son residentes y anidan en cavidades. Dadas las importantes similitudes entre las dos regiones, es probable que, como en Fennoscandia, la expansión de las actividades forestales comerciales en el este de Canadá resulte en la declinación significativa de varias especies residentes.

Comparisons of the effects of logging and fire as disturbance agents on the composition of bird assemblages in boreal ecosystems are still lacking or are limited to the short-term impacts of clear-cutting. In Quebec, where the boreal forest is largely dominated by black spruce (Picea mariana (Mill.) B.S.P.) stands, we surveyed 140 point-count stations in 3 postlogging and 4 postfire development stages determined according to the height of the regenerating spruce trees. Species richness did not vary among forest development stages, but bird abundance was higher in recent clearcuts. Recently disturbed areas were characterized by open-land bird assemblages dominated by Neotropical migrants, which reached their highest abundance in clearcuts. Moreover, logged stands were distinguished from burned sites by the absence of cavity-nesting birds. Forest-bird assemblages reestablished themselves as soon as young spruces reached the sapling stage. However, the Black-backed Woodpecker (Picoides arcticus), Three-toed Woodpecker (Picoides tridactylus), and Brown Creeper (Certhia americana) were restricted to mature stands or recent burns and are thus likely to be negatively affected by modern forestry, which involves fire suppression and short logging rotations. We suggest that retention of larger areas of continuous mature forest might be essential to maintain these species in managed regions.

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