Distribution and Host Plants of \u3ci\u3eCorthylus Punctatissimus\u3c/i\u3e (Coleoptera: Scolytidae) in the Lower Peninsula of Michigan

(excerpt) The pitted ambrosia beetle. Corthylus punctatissimus Zimmerman, infests woody saplings and shrubs 14 mm in diameter or less. The beetle bores an entrance hole into the main stem at soil level and constructs a main gallery tunnel which generally spirals downward in the stem. Egg-niche construction is followed by inoculation of symbiotic fungi and oviposition. The main stem of the host tree wilts as a result of the girdling activity of the beetle. Finnegan (1967) described the life history of C. punctatissimus infesting Acer saccharum Marshall in Ontario and Quebec

Observations of the Habits of \u3ci\u3eCorthylus Punctatissimus\u3c/i\u3e (Coleoptera: Scolytidae) Infesting Maple Saplings in Central Michigan

Corthylus punctatissimus, the pitted ambrosia beetle, infested and killed maple saplings that were 3-12 years of age with a basal diameter of 4-14 mm. The habits of the parental pair of adults are described. The beetles construct a spiral gallery system with about five egg niches per host. Half the brood reaches adult stage during the summer with a sex ratio of 1:1. No relationship was found between the number of niches, length of gallery system, or diameter of stem

Long-Term Soil Productivity Study: 25-Year Vegetation Response to Varying Degrees of Disturbance in Aspen-Dominated Forest Spanning the Upper Lake States

Installations of the Long-Term Soil Productivity Study were established in northern Minnesota and Michigan at the Chippewa, Ottawa, and Huron-Manistee National Forests (NFs) in the early 1990s and have since provided a wealth of data for assessing the response of aspen-dominated forest ecosystems to varying levels of organic matter removal and soil compaction. An assessment of 25-year standing woody biomass indicates that neither whole-tree harvest nor whole-tree harvest combined with forest floor removal reduced forest productivity on silt-loam soils compared with conventional, stem-only harvest; however, moderate and heavy compaction did negatively impact aspen biomass and stem densities. In contrast, whole-tree harvest reduced standing biomass of aspen and all species combined on sandy soils at the Huron NF while compaction had no discernable impact. Neither treatment factor affected vegetation response at the Ottawa NF (clay soils), but reduced sample size at this site may have increased variability. Over all, the response of standing biomass and forest structure to organic matter removal and compaction treatments demonstrate that the sustainability of practices such as whole-tree harvesting and associated potential for soil impacts varies with site conditions, even when stands are dominated by the same species (e.g., Populus tremuloides)

The State of the System and Steps Toward Resilience of Disturbancedependent Oak Forests

Current ecological, economic, and social conditions present unique challenges to natural resource managers seeking to maintain the resilience of disturbance-dependent ecosystems, such as oak (Quercus spp.) forests. Oak-dominated ecosystems throughout the U.S. have historically been perpetuated through periodic disturbance, such as fire, but more recently show decline given shifting disturbance regimes associated with human land management decisions. We characterized the state of the social-ecological oak forest ecosystem in the midwestern U.S. through the perspectives of 32 natural resource professionals. Data from interviews with these change agents provided an integrative understanding of key system components, cross-scale interactions, dependencies, and feedbacks. Foremost, private landowner management decisions figured prominently in influencing oak regeneration success and were directly and indirectly shaped by a suite of interdependent ecological, e.g., deer herbivory, invasive shrub occurrence; economic, e.g., the cost of oak regeneration practices, the stumpage value of maple as compared to oak; and social forces, e.g., forestland parcelization, and personal relationships. Interviewees envisioned, and often preferred, a decline in oak dominance throughout the region, pointing to issues related to general landowner unwillingness to restore oak, the current trajectory of forest change, the threat of forest loss due to parcelization and housing development, and a combination of ecological and social factors that decrease the economic feasibility of restoration efforts. However, a decline in oak dominance may result in ecological communities that have no compositional equivalent on record and may not offer a desirable endpoint. Increasing social support offers the potential to enhance system capacity to manage for oak

Integrating LANDIS model and a multi-criteria decision-making approach to evaluate cumulative effects of forest management in the Missouri Ozarks, USA

Public forest management requires consideration of numerous objectives including protecting ecosystem health, sustaining habitats for native communities, providing sustainable forest products, and providing noncommodity ecosystem services. It is difficult to evaluate the long-term, cumulative effects and tradeoffs these and other associated management objectives. To demonstrate the capabilities of techniques suitable to support such evaluations we combined a spatially explicit landscape-scale, succession and disturbance model (LANDIS) with wildlife habitat suitability models and a multi-criteria decisionmaking framework to compare four management alternatives across a 700 km2 area of the Mark Twain National Forest in Missouri, USA. We estimated the combined, cumulative effects of tree species succession, fire disturbance, fuel accumulation, fire hazard, wind disturbance and timber harvest on future species composition, age class distribution, timber products, and wildlife habitat suitability for eastern wild turkey and eastern gray squirrel. We applied a structured, multi-criteria, decision-making framework (PROMETHEE) to analyse forest conditions and to derive weighted composite scores for seven criteria applied to each alternative management scenario. The approach provides a systematic, repeatable, transparent, spatially explicit framework for evaluating the long-term, landscape-scale cumulative effects of management alternatives. The methodology does not encompass all the factors that influence decisions about public land management, but it captures many important ones. The underlying models provide a way to test and accumulate knowledge about forest response to succession and disturbance and to use those relationships to support decision making with the best available science

Integrating LANDIS model and a multi-criteria decision-making approach to evaluate cumulative effects of forest management in the Missouri Ozarks, USA

Public forest management requires consideration of numerous objectives including protecting ecosystem health, sustaining habitats for native communities, providing sustainable forest products, and providing noncommodity ecosystem services. It is difficult to evaluate the long-term, cumulative effects and tradeoffs these and other associated management objectives. To demonstrate the capabilities of techniques suitable to support such evaluations we combined a spatially explicit landscape-scale, succession and disturbance model (LANDIS) with wildlife habitat suitability models and a multi-criteria decisionmaking framework to compare four management alternatives across a 700 km2 area of the Mark Twain National Forest in Missouri, USA. We estimated the combined, cumulative effects of tree species succession, fire disturbance, fuel accumulation, fire hazard, wind disturbance and timber harvest on future species composition, age class distribution, timber products, and wildlife habitat suitability for eastern wild turkey and eastern gray squirrel. We applied a structured, multi-criteria, decision-making framework (PROMETHEE) to analyse forest conditions and to derive weighted composite scores for seven criteria applied to each alternative management scenario. The approach provides a systematic, repeatable, transparent, spatially explicit framework for evaluating the long-term, landscape-scale cumulative effects of management alternatives. The methodology does not encompass all the factors that influence decisions about public land management, but it captures many important ones. The underlying models provide a way to test and accumulate knowledge about forest response to succession and disturbance and to use those relationships to support decision making with the best available science

Using an ecological land hierarchy to predict seasonal‐wetland abundance in upland forests

Abstract. Hierarchy theory, when applied to landscapes, predicts that broader-scale ecosystems constrain the development of finer-scale, nested ecosystems. This prediction finds application in hierarchical land classifications. Such classifications typically apply to physiognomically similar ecosystems, or ecological land units, e.g., a set of multi-scale forest ecosystems. We speculated that hierarchical constraint also controls the development of small, nested ecosystems that are structurally distinct from the constraining matrix. We tested this hypothesis using seasonal wetlands in upland forest. Specifically, we related seasonal-wetland abundance in upland forest stands to multi-scale terrestrial ecological units, as defined by hierarchical combinations of regional physiography, glacial landform, soils, and forest cover. Moreover, we determined the spatial scale of terrestrial ecological unit that is the best predictor of seasonal-wetland abundance. Our study area is mapped into a set of nested terrestrial ecological units, including two subsections (differing in physiography), four land-type associations (glacial landforms), and 11 land types (forest vegetation, soil). We used a geographic information system to determine seasonal wetland densities in 16-ha plots located within the nested terrestrial ecological units. Cumulative plot frequency distributions of wetland density did not differ between subsections; 50% of plots contained no wetlands, 38% contained 1-3 wetlands, and 12% contained Ն4 wetlands. Frequency distributions differed among land-type associations (LTA). Ninety percent of plots on a glacial lake plain contained no wetlands, compared to 63%, 42%, and 38% for outwash, end moraine, and ground moraine LTAs, respectively. Ten percent of plots on the lake plain contained 1-3 wetlands, compared to 32%, 48%, and 43% for the outwash, end moraine, and ground moraine, respectively. The remaining plots on the latter three LTAs contained Ͼ3 wetlands. Frequency distributions rarely differed among land types. Compared to occurrence, identity and scale of the ecological unit were poorer predictors of actual wetland densities. Regression tree analysis, while significant, explained only 11.6% of variation in wetland density among plots. Still, the leaves of the regression tree differed in densities primarily based on LTA. Our results demonstrate that identity of constraining upland forest ecosystem explains significant amounts of variation in seasonal wetland abundance. We identify glacial landform as the scale of ecological unit having the greatest control over seasonal wetland abundance. We focus on seasonal wetlands in forests, yet our approach should apply to other small, nested ecosystems. This approach may facilitate conservation management of small, nested ecosystems by providing likelihood estimates of occurrence within mapped terrestrial ecological units

Relationships between growth, quality, and stocking within managed old-growth northern hardwoods

Abstract: An understanding of long-term growth dynamics is central to the development of sustainable uneven-aged silvicultural systems for northern hardwood forests in eastern North America. Of particular importance are quantitative assessments of the relationships between stocking control and long-term growth and quality development. This study examined these relationships in a long-term silviculture experiment established in northern hardwood stands in the Upper Peninsula of Michigan, USA. Stands were old growth at the onset of the experiment and were maintained at three residual stocking levels (11.5, 16.1, and 20.7 m 2 ·ha -1 ) over a 57-year period. Several aspects of long-term stocking control were evaluated, including the effects of residual stocking on tree quality development and the relationships between stand stocking and individual tree growth and stand-level production. Results suggest that residual stocking had little impact on quality development, likely due to the initial old-growth condition of the stands examined. In contrast, our results indicate that a range of stand densities will maintain acceptable rates of stand-level production in selection systems and that growth can be shifted between diameter classes depending on desired future stand conditions. Résumé : La compréhension de la dynamique de la croissance à long terme est essentielle pour mettre au point des systè-mes sylvicoles durables appliqués aux forêts inéquiennes de feuillus nordiques dans l'est de l'Amérique du Nord. Il est particulièrement important de quantifier les relations à long terme entre la surface terrière résiduelle et la croissance et le développement de la qualité. Cette étude se penche sur ces relations dans le cadre d'une expérience sylvicole de longue durée établie dans des peuplements de feuillus nordiques sur la péninsule supérieure du Michigan, aux États-Unis. Au début de l'expérience, la surface terrière de ces vieux peuplements a été abaissée à trois niveaux différents (11,5, 16,1 et 20,7 m 2 ·ha -1 ) qui ont été maintenus pendant une période de 57 ans. Plusieurs aspects du maintien de la surface terrière ont été évalués, dont l'effet de la surface terrière résiduelle sur le développement de la qualité des arbres et la relation entre la surface terrière et la croissance aux échelles de l'arbre individuel et du peuplement. Les résultats indiquent que la surface terrière résiduelle a eu peu d'impact sur le développement de la qualité, probablement parce que les peuplements étudiés étaient initialement des vieilles forêts. Par contre, nos résultats indiquent qu'une gamme de densités résiduelles est en mesure de maintenir des taux acceptables de production à l'échelle du peuplement dans les systèmes de jardinage et que la croissance peut être déplacée entre les classes de diamètre en fonction des conditions futures du peuplement que l'on désire. [Traduit par la Rédaction