Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols Used xiii 1. The Importance of Islands 3 2. Area and Number of Speicies 8 3. Further Explanations of the Area-Diversity Pattern 19 4. The Strategy of Colonization 68 5. Invasibility and the Variable Niche 94 6. Stepping Stones and Biotic Exchange 123 7. Evolutionary Changes Following Colonization 145 8. Prospect 181 Glossary 185 References 193 Index 201

The Theory of Island Biogeography

Glyphosate-based weed control products are among the most widely used broad-spectrum herbicides in the world. The herbicidal properties of glyphosate were discovered in 1970, and commercial formulations for nonselective weed control were first introduced in 1974 (Franz et al. 1997). Formulations of glyphosate, including Roundup® Herbicide (RU)1 (Monsanto Company, St. Louis, MO), have been extensively investigated for their potential to produce adverse effects in nontarget organisms. Governmental regulatory agencies, international organizations, and others have reviewed and assessed the available scientific data for glyphosate formulations and independently judged their safety. Conclusions from three major organizations are publicly available and indicate RU can be used with minimal risk to the environment (Agriculture Canada 1991; USEPA 1993a; WHO 1994). Several review publications are available on the fate and effects of RU or glyphosate in the environment (Carlisle and Trevors 1988;Smith and Oehme 1992 ; Malik et al. 1989;Rueppel et al. 1977; Sullivan and Sullivan 1997;Forestry Canada, 1989). In addition, several books have been published about the environmental and human health considerations of glyphosate and its formulations (Grossbard and Atkinson 1985; Franz et al. 1997). In addition, RU and other glyphosate formulations have been selected for use in a number of weed control programs for state and local jurisdictions in the United States. Many of these uses require that ecological risk assessments be conducted in the form of Environmental Impact Statements or Environmental Assessments. These documents are comprehensive and specific to local use situations. Documents are available for risk assessments in Texas, Washington, Oregon, Pennsylvania, New York, Virginia, and other states (USDA 1989;USDA 1992;USDA 1996;USDA 1997;USDI 1989; Washington State DOT 1993).

Ecotoxicological Risk Assessment for Roundup ® Herbicide

Plantations are established for a variety of reasons including wood production, soil and water conservation, and more recently, carbon sequestration. The effect of this growing land-use change on biodiversity, however, is poorly understood and considerable debate exists as to whether plantations are ‘green deserts’ or valuable habitat for indigenous flora and fauna. This paper synthesizes peer-reviewed articles that provide quantitative data on plant species richness in plantations and paired land uses, most often representative of pre-plantation land cover. The results of this synthesis suggest that the value of plantations for biodiversity varies considerably depending on whether the original land cover is grassland, shrubland, primary forest, secondary forest, or degraded or exotic pasture, and whether native or exotic tree species are planted. The results of this study suggest that plantations are most likely to contribute to biodiversity when established on degraded lands rather than replacing natural ecosystems, such as forests, grasslands, and shrublands, and when indigenous tree species are used rather than exotic species. These findings can help guide afforestation and reforestation programs, including those aimed at increasing terrestrial carbon sequestration.

/pdf/does-plantation-forestry-restore-biodiversity-or-create-2zpkkqbbl0.pdf

Does plantation forestry restore biodiversity or create green deserts? A synthesis of the effects of land-use transitions on plant species richness.

1. Introduction.- 2. Tree Form and Stem Taper.- 3. Tree-stem Volume Equations.- 4. Tree Weight and Biomass Estimation.- 5. Quantifying Tree Crowns.- 6. Growth Functions.- 7. Evaluating Site Quality.- 8. Quantifying Stand Density.- 9. Indices of Individual-tree Competition.- 10. Modeling Forest Stand Development.- 11. Whole-stand Models for Even-aged Stands.- 12. Diameter-distribution Models for Even-aged Stands.- 13. Size-class Models for Even-aged Stands.- 14. Individual-tree Models for Even-aged Stands.- 15. Growth and Yield Models for Uneven-aged Stands.- 16. Modeling Response to Silvicultural Treatments.- 17. Modeling Wood Characteristics.- 18. Model Implementation and Evaluation.-

Modeling Forest Trees and Stands

A bhstrt. The design of the life cycle of pin cherry (Prlmlits Ape(/vasO i(mi L. ), a successional xpecies common on disturbed sites througlhout Much of the northern hardwood and boreal forest ecosystems, assures that its occurrence is integrated into the pattern of disturbance in the climax ecosysten. The combination of burlied seed strategy and the nobility offered through avian consuLmption of fruits ensures reasonably large populations of buried, viable seeds in the soils of forests well after the disappearance of pin cherry from a particular site. Soil sampling data indicate that Sufficient numbers of viable pin cherry seeds reside in the soils of second-growth forests in central New Hampshire to account 'for the dense stands frequently observed after cutting or burning. Further, germination of these bur-ied seeds is apparently triggered by some factor(s) associated with formation of a large gap. By ,age 25 or 30, when pin cherry individuals are dying rapidly, Sufficient numbers of seeds have been produced and disseminated in a dormant condition for the cycle to renew itself with the Subsequent occurrence of major disturbance. In high density stands pin cherry grows rapidly, with early attainment of canopy closure (high leaf area index), and rapid attainment of high values of net annual production and nutrient, accunmulaltion.

The role of pin cherry (prunus pensylvanica l.) in the maintenance of stability in northern

In northern forests, cryptogams (spore producing plants) occupy a key position in forest ecosystem diversity and function. Forest harvesting and silvicultural practices have the potential to reduce...

The effects of silvicultural disturbances on cryptogam diversity in the boreal-mixedwood forest

Differences in yield-density models derived from an additive experimental design were used to compare the relative competitiveness of nine early-successional boreal forest plants (aster, grass, fireweed, fern, raspberry, willow, alder, birch, and aspen) on jack pine (Pinus banksiana Lamb.) and black spruce (Picea mariana (Mill.) BSP). A randomized complete block split-split-plot design with three replications blocked on soil type was used. Initial density gradients were 0-4 plants/m2 for woody and 0-8 plants/m2 for herbaceous species. An a priori analytical approach that compared a full model (using linear regression analysis of 4th-year stem diameter of conifers under increasing cover and height of competitors) to various reduced models was used to assess competition. Increasing cover and (or) height of all competitors (except fern) significantly (P < 0.05) decreased conifer stem diameter. The final regression model (based on visual estimates of cover and differences in initial conifer size) accounted fo...

Relative competitiveness of nine early-successional boreal forest species associated with planted jack pine and black spruce seedlings

Effects of forest floor disturbances by mechanical site preparation on floristic diversity in a central Ontario clearcut.

Cover and height of vegetation before and one growing season after: 1) motor-manual cutting, 2) mechanical brush cutting (Silvana Selective/Ford Versatile), 3) aerial application of Release® (a.i. triclopyr) herbicide, 4) aerial application of Vision® (a.i. glyphosate) herbicide, and 5) control (no treatment) were quantified. Multivariate analysis permitted the study of vegetation response as a whole, while accounting for correlations that exist among the individual vegetation groups. Univariate analysis were used to study the responses of individual vegetation groups. Although no pre-treatment differences in percent cover were observed (P = 0.128), deciduous tree, shrub, forb, grass, and sedge groups responded differently to the treatments after one growing season (P < 0.018). Post-treatment cover of deciduous tree and shrub groups was lower in herbicide treated plots than in cut plots. Forb, grass and sedge covers varied greatly among treatments. Brush saw and Silvana Selective treatments decreased cove...

Motor–manual, mechanical, and herbicide release affect early successional vegetation in northwestern Ontario

The practice of clear-cutting, followed by site preparing with mechanical equipment, planting a single tree species, and applying herbicides, has recently been cited as a procedure that creates mon...

F. Wayne Bell

Papers

The effects of silvicultural disturbances on cryptogam diversity in the boreal-mixedwood forest

Relative competitiveness of nine early-successional boreal forest species associated with planted jack pine and black spruce seedlings

Effects of forest floor disturbances by mechanical site preparation on floristic diversity in a central Ontario clearcut.

Motor–manual, mechanical, and herbicide release affect early successional vegetation in northwestern Ontario

The effects of silvicultural disturbances on the diversity of seed-producing plants in the boreal mixedwood forest