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The woodwasp, Sirex noctilio Fabricius, is an exotic pest of Pinus L. in the southern hemisphere and North America, and it is an emerging threat in northeastern China. Adult woodwasps have numerous insect competitors for oviposition substrates, and developing larvae must compete for resources with other subcortical invaders. Its mutualistic fungus Amylostereum areolatum (Fr.) Boidon, is less competitive than many other fungal colonists present in pine ecosystems. This study investigated the effects of incidental, host-colonizing fungi on the growth and development of woodwasp larvae and A. areolatum. Fungi were isolated from dead S. noctilio larvae within galleries (primarily Trichoderma Pers, Ophiostoma Sydow, and Sphaeropsis Sacc.), and effects of these fungi on woodwasp brood survival were investigated via inoculations of S. noctilio -infested logs. Larval mortality was significantly increased in sample logs inoculated with Ophiostoma minus (Hedgc.) Sydow Phlebiopsis gigantea (Fr.) Jülich, Trichoderma atroviride Bissett, Trichoderma viride Pers, and Trichoderma harzianum Rifai. Inoculation of logs with O. minus resulted in the highest mortality and greatest reductions in wood moisture content. When grown on artificial media, these fungi grew faster than and inhibited growth of A. areolatum mycelium. We propose that the adverse effects of incidental fungi on the survival of S. noctilio larvae may be caused at least in part by an indirect mechanism involving inhibition of the fungal symbiont. The findings provide potentially valuable information for suppressing S. noctilio populations using microbial control agents. [ABSTRACT FROM AUTHOR]

Abstract: Understanding the characteristics of geographic ranges is a basic premise of all biogeographical research. One such measure of geographic ranges is range shape. The shapes of ranges reveal processes that affect the habitable limits of their respective species. I investigated the relative range elongation, with respect to maximum north-south distance and maximum east-west distance, of 269 North American tree species. These data provide evidence that species with smaller ranges tend to be elongated north-south and species with larger ranges tend to be elongated east-west. These results are similar to previously published data on land mammals and land birds of North America, but differ from data published on North American ectotherms. This pattern is likely a result of species with small ranges being limited by local north-south-trending topography and species with large ranges being limited by major east-west-oriented climatic zones, and is not merely an artifact of Rapoport's Rule. Previously, range elongation has been limited to graphical representation with no ability to compare range geometry with other biogeographical characteristics. Now, an explicit measure of range shape exists to compare to other characteristics. [ABSTRACT FROM AUTHOR]

The article presents the study on the stand structure and the small mammals in young lodgepole pine forests in North America. It states that the mean total abundance of small mammals were similar among stands in 1990-1991 but low-density and old growth stands had most mammals in 1998. It mentions that the heavily thinned lodgepole pine stands developed attributes such as large trees, crowns, and diverse vegetative understories.