Geographically isolated wetland and surrounding landscape features affect the ecology and life history of amphibian species. We used multistate mark recapture methods and data from over 30,000 captures of adult Ambystoma opacum to explore how survival, breeding, and movement probabilities differed among wetlands surrounded by regenerating 20-year-old clearcuts and mature 100-year-old forest stands. Survival varied among ponds and years but did not differ between regenerating and mature forest habitats. Both sexes at all ponds incurred dramatic mortality during the non-breeding season of a drought year (2001–2002). Females that skipped one or more breeding opportunities had higher breeding probabilities the following year than did successive breeders. Females exiting into regenerating forests had lower breeding probabilities at two of the three ponds. Breeding salamanders tended to make local movements from regenerating to mature forests, particularly when exiting the pond basin. Landscape movements between ponds were generally low, with few individuals moving from mature to regenerating forest habitats. We conclude that clearcuts continue to negatively impact some demographic parameters of salamanders 20 years post-cutting, but other environmental factors may mitigate these effects, and that populations are probably capable of complete recovery, particularly if some mature forest is retained.

Local floras are a basis of biogeography, ecology, evolution, and systematics, and they add value to research sites. Mountain Lake Biological Station is located between 1,150 and 1,319 m elevation in southwestern Virginia on infertile, acidic soils supporting a second-growth forest strongly dominated by Quercus rubra about 150 years old. We sampled vascular vegetation on 352 randomly distributed plots 10m in diameter with 8 subplots of 1 m2 each. The plots contained 175 taxa (including 7 taxa that included 16 lumped species); other fieldwork added 43 species for a total of 227 species in the forest. We excluded disturbed areas around buildings, roadsides, and ponds that harbor many ruderal and invasive species. Average detection probability of a species on a plot was estimated to be 75%. We recorded binary occurrence (present or absent on a plot) and prevalence (occurrence on 0, 1, 2, … 8 subplots per plot) and a set of environmental variables measured in the field or laboratory, or estimated from LIDAR data collected by NEON. Nonmetric multidimensional scaling ordination rejected the null hypothesis of random distributions of herbaceous species among plots. Cluster analysis defined eight groups of plots based on prevalence of herbaceous species to illuminate rejection of the null hypothesis. The environments of these clusters, determined only by their floras, demonstrated the importance of rock type, soils, solar radiation, canopy height, and topography in determining the local distribution of species. Significant differences among assemblages and their environments occurred within a superficially homogeneous forest.

The high abundance of ungulates in temperate zone forests is affecting biodiversity and ecosystem functions worldwide. A randomized, replicated experiment excluded white-tailed deer, Odocoileus virginianus, from six 10x10 m fenced plots for 10 years; six unfenced plots were maintained as controls. The effects of chronic herbivory were assayed by comparisons using the mean responses of ground-level vegetation in nine subplots within each of the 12 plots. Deer had a small effect on species richness but a strong effect on species prevalence, cover, and biomass, with repeatable differences in the responses of taxa to the treatments. Graminoids were favored in control plots, many other monocots and several dicots were favored in fenced plots, and parasitic plants and chemically defended herbs showed few detectable responses to fencing. The height of the vegetation represented by the shrub Vaccinium erythrocarpum and the herb Medeola virginiana was significantly taller in fenced than in control plots. This experiment demonstrated that many forest herbs, especially those in the Liliaceae sensu lato, tolerate repeated browsing without flowering, probably for decades. When released from browsing, the time required for these species to sequester sufficient resources to flower and successfully develop seeds varied from 1 to 10 years among species. Managers of forest ecosystems must consider the impacts of game management on biodiversity.

A table showing numbers of individual adult and recently metamorphosed Ambystoma tigrinum entering and exiting the study ponds over four years.

The relationship between estimated pond and season-specific newt densities and transition probabilities between migratory states for male and female Notophthalmus viridescens.

A table showing model-averaged transition probability estimates between breeding and nonbreeding states within and between populations of Ambystoma tigrinum tigrinum.

My paper trail started with the trees before they became paper. Family walks in the woods where my parents taught me the wild flowers and trees of the Blue Ridge Mountains at a young age sowed the seeds that germinated and flourished when I attended Nature Camp sponsored by the Virginia Federation of Garden Clubs as a camper, then counselor, and instructor of botany and herpetology (1955–1964). Entering college, I was an experienced naturalist and woodsman who had been indoctrinated in traditional concepts of conservation by Nature Camp mentors from the wildlife group at Virginia Tech (Henry Mosby and Byrd McGinnis) and Max Carpenter, a wildlife Biologist with the state game commission. My higher education started in 1962 at Duke where Dan Livingstone taught me ecology, limnology, the importance of mathematics, and how to read the primary literature; and guided my undergraduate shift from natural history (learning names of trees) to theoretical ecology (consuming trees). As an undergraduate I bought and read four books that were not required for any course: Ernst Mayr's Animal Species and Evolution, Larry Slobodkin's Growth and Regulation of Animal Populations, George Willams's Adaptation and Natural Selection, and Charles Darwin's Voyage of the Beagle. That was nearly fifty years ago, but I can still recommend these works to anyone who is interested in the foundations of evolutionary ecology. I entered graduate school at the University of Michigan in 1966 to train as a vertebrate ecologist, inspired by a seminar visit to Duke by Larry Slobodkin. At Michigan I quickly was introduced to field experiments as a way to test theory with the prime examples of Joe Connell's (1961a, b) work on barnacles, and the then fresh manipulations of Bob Paine (1966) in the rocky intertidal zone. Fred E. Smith opened the door to experimental design by adding the general linear model to my tool box. I had found my calling but needed my own research approach. I looked among fellow graduate students for examples and insight. John Vandermeer became my role model for ideas and Warren Brockelman my mentor on how to test them. I took Vandermeer's (1969) dissertation design for testing the importance of higher-order interactions in competition among protozoan assemblages in test tubes, and used field cages Brockelman (1969) had built for his research testing for density dependence among tadpoles under realistic field conditions. My dissertation research tested the importance of higher-order interactions among three species of salamanders under nearly natural conditions provided by recycling Brockelman's cages. Vandermeer's dissertation had its conceptual roots in Alfred Lotka's (1932) first use of simultaneous linear equations to represent the interactions between species at competitive equilibrium. This formulation remained dormant until Richard Levins (1968) gave it the name “the community matrix” and pointed out the insights that could flow from it. In the late 1960s, most ecologists were still enamored of mathematics, simple models, and competition as the force that structured natural communities. In retrospect this view was a bit odd, given our love of Paine's demonstration of the importance of Pisaster predation in a clearly non-equilibrium system. The “etude” by Hairston, Smith, and Slobodkin (1960) was still a new, exciting synthesis—and they were my teachers in Ann Arbor. Vandermeer was surprised by his results, expecting the linear, additive model to fail when tested with real, albeit “simple” organisms in a simplified environment. This surprise justified my repeating his design, using more “complex” vertebrates under nearly realistic conditions. My results were not surprising; higher-order terms in the model were important (Wilbur 1972). My most highly cited paper, Wilbur and Collins (1973), arose from the long Michigan winters when the amphibians were under the snow and I was in the library, urged on by my friend and mentor Don Tinkle, who also had been inspired by George Williams' book and the work of David Lack (1954). Returning to Duke as an assistant professor (1973) I quickly abandoned the community matrix as a conceptual framework in favor of Paine's concepts of the importance of predation and historical effects in communities where equilibrium is only an idealized state that serves as a standard to test actual events. Natural history returned to be more important to me than simple theoretical constructs (e.g., Wilbur and Alford 1985). Don Tinkle had us read E. B. Ford's Ecological Genetics as first-year graduate students, but it was not until I started teaching with Janis Antonovics at Duke that I appreciated the power of watching evolution in action, as he repeatedly dismissed the myth that ecological time and evolutionary time are different (e.g. Harris et al. 1990). My “Duke phase” is summarized in Wilbur 1997. In the “Virginia phase” of my career, beginning in1991, more time was spent fostering the research of others and teaching natural history as Director of Mountain Lake Biological Station (MLBS), but I continued to train students in community ecology. My own interests shifted back to population ecology, and my approach used long-term capture–recapture studies of salamanders (Bailey et al 2004, Church et al. 2007, Grayson and Wilbur 2009, Grayson et al. 2011) and trees (in preparation). This shift started with a chance seminar visit to Charlottesville by Jim Nichols, the guru of maximum likelihood methods for estimating population parameters using capture–recapture data. Additional motivation came from shifting my advanced course in population and community ecology to population and conservation ecology. Peter Kareiva's teaching of conservation biology at MLBS inspired me; Morris and Doak (2002) provided the textbook that made it possible. I have found population ecology to be less flashy, but more enduring, than community ecology because my current research is focused on parameter estimation and hypothesis testing in natural, unmanipulated populations. My field experiments on aquatic food webs always were under a shadow of doubt about the effects of scale and isolation of my closed systems (Wilbur 1989). Regrets? I wish that I had been exposed to the scientific work of Aldo Leopold at an earlier stage. At Nature Camp we learned about the Kaibab deer outbreak and the interaction between food, cover, and predators, but I never learned about game management in my university classes in ecology. Stoddard (1931) and Leopold (1933) had as much to teach ecologists as Elton (1927) taught them! Reading Leopold would have helped me find the soul in community ecology; the Lotka-Volterra model may hold the essence but not the soul.

We conducted a meta-analysis of local hunting practices affecting the carnivores of forested Africa and Madagascar to collate the information available on this subject and to assess underlying trends in offtake rates. We located.. relevant articles in a detailed literature search; the data included taxa reported as hunted, the purpose of hunting and the hunting method. The families most reported as hunted were Herpestidae and Viverridae (excluding Civettictis civetta), with 32.7 and 19.2% of total records, with C. civetta comprising 13.5% of records and Nandina binotata 9.9%. Hunting for consumption was the most commonly reported purpose (61.7% of all records). Sale for consumption was associated with 60.5% of all consumption records, and sale of any kind was reported for 56.6% of all records. The number of carnivore carcasses or parts sold at urban markets rose by 8.2% from the 1990s to the 2000s. The commonest hunting methods were traps (31.0% of records) and guns (16.6%). For records reporting the use of guns, 89.4% also reported sale of some kind. We conclude that carnivores are hunted pervasively across the forested regions of mainland Africa and Madagascar, and offtake rates for both personal use and income are probably increasing. These findings have implications for efforts to protect dwindling forest ecosystems and to establish sustainable consumptive practices.

Fire history is an important aspect of the natural disturbance pattern of many types of forested ecosystems. Nonetheless, many forests and corresponding management plans lack quantitative information on fire interval, frequency, and seasonality. This project examined the fire history at Price Mountain, Virginia, using fire scar samples and tree-ring analyses from live tree chronologies. Additionally, this project investigated the fire scarring potential of two little-studied species, black gum (Nyssa sylvatica) and sourwood (Oxydendrum arboreum), as well as described the age-structure of the current stand. We hypothesized that fire frequency would be high prior to the fire suppression era, given the proximity to an historical railroad track at the base of the mountain and susceptibility to lightning due to elevation. Six major fire years occurred between 1861 and 1925 at an average interval of 14 years, followed by a period of no fires. Two-thirds of the fires burned early in the season. There was an initial establishment of sourwood and chestnut oak (Quercus prinus) from 1930-1940 as well as another establishment peak between 1950 and 1960 after a major logging event. Pine (Pinus pungens and Pinus rigida) species established between 1870 and 1930. Reconstructed fire history and age structure informs land managers that repeated fires occurred in this Appalachian ridge top forest and that modern forest structure is in part the legacy of historic fires and fire suppression.

This study documents 25 y of change in the abundance of Quercus rubra (northern red oak) and Quercus alba (white oak), in a previous chestnut (Castanea castanea)-oak forest in the Southern Appalachians of the eastern U.S.A. Spatially explicit data front 1983-1984 and 2007-2008 of individually mapped trees on two plots in southwestern Virginia were used to examine how the basal area and density of all tree species changed, with specific attention to recruitment, growth, and mortality patterns of Q. rubra and Q. alba. Since the 1980s there has been an increase in the number of shade tolerant trees, primarily Acer pensylvanicum (striped maple), and a decrease in the number of shade intolerant and intermediate shade tolerant trees, including both Q. rubra and Q. alba. We found a negative correlation between A. pensylvanicum abundance and Quercus seedling abundance and a positive correlation between light availability and Quercus seedling abundance. Both Q. rubra and Q. alba have experienced self-thinning, and the previous oak-chestnut forest will likely become increasingly dominated by maples and other shade tolerant species.

ABSTRACT Hurricanes are an important part of the natural disturbance regime of the Yucatán Peninsula with the potential to alter forest structure and composition, yet investigations of species‐level responses to severe winds are limited in this region. The effect of a category 5 hurricane (Hurricane Dean, 21 August 2007) on dry tropical forests across the southern Yucatán was examined with respect to tree damage, mortality, and sprouting. Damage was assessed 9–11 mo following the hurricane in 92 (500 m 2 ) plots stratified by wind speed and normalized difference vegetation index (NDVI) change classes over a 25,000 km 2 study area. We investigated the relative importance of biotic ( i.e ., species, size, and wood density) and abiotic ( i.e ., wind speed) factors to better explain patterns of damage. Overall mortality was low (3.9%), however, mortality of less common species (8.5%) was elevated more than fourfold above that of 28 common species (1.8%), indicating immediate selective consequences for community composition. Species varied in the degree and type of damage experienced, with susceptibility increasing with tree diameter and height. Wood density influenced damage patterns only in areas where a critical threshold in storm intensity was exceeded (wind speeds ≥210 km/h). Although overall, damage severity increased with wind speed, common coastal species were more resistant to damage than species distributed farther inland. Our findings suggest that selective pressure exerted by frequent hurricane disturbance has, and will, continue to impact the floristic composition of forests on the Yucatán Peninsula, favoring certain wind‐resistant species. Abstract in Spanish is available at http://www.blackwell‐synergy.com/loi/btp .

Species with partial migration, where a portion of a population migrates and the other remains residential, provide the opportunity to evaluate conditions for migration and test mechanisms influencing migratory decisions. We conducted a five-year study of two populations of red-spotted newts (Notophthalmus viridescens), composed of individuals that either remain as residents in the breeding pond over the winter or migrate to the terrestrial habitat. We used multistate mark-recapture methods to (1) test for differences in survival probability between migrants and residents, (2) determine if migrants breed every year or skip opportunities for reproduction, and (3) estimate the frequency of individuals switching migratory tactic. We used estimates of life history parameters from the natural populations in combination with previous experimental work to evaluate processes maintaining partial migration at the population level and to assess mechanisms influencing the decision to migrate. Based on capture-recapture information on over 3000 individuals, we found that newts can switch migratory tactics over their lifetime. We conclude that migrants and residents coexist through conditional asymmetries, with residents having higher fitness and inferior individuals adopting the migrant tactic. We found that newts are more likely to switch from residency to migrating than the reverse and males were more likely to remain as residents. Migration differences between the sexes are likely driven by reproduction benefits of residency for males and high energetic costs of breeding resulting in lower breeding frequencies for females. Environmental conditions also influence partial migration within a population; we found support for density-dependent processes in the pond strongly influencing the probability of migrating. Our work illustrates how migration can be influenced by a complex range of individual and environmental factors and enhances our understanding of the conditions necessary for the evolution and maintenance of partial migration within populations.

Partial migration, variation in the percentage of a population that completes a migration, can be influenced by the local environment and condition of an individual. We examined the direct and interacting effects of habitat quality and gender on migration decision by manipulating population density and sex ratio in a factorial field experiment using aquatic enclosures. In partially migrating red-spotted newts (Notophthalmus viridescens), we measured the percentage of newts migrating to the terrestrial habitat vs. overwintering as pond residents. Density significantly influenced migration, with 63% of newts migrating from high-density enclosures compared to 39% from low-density enclosures. Newts also migrated earlier from high-density enclosures, but no significant effects of the sex ratio treatment were found. Females migrated earlier than males, and 64% more females developed the migrant phenotype, suggesting important sex-based trade-offs of migration. No differences were found between migrants and residents in initial body size, counter to our prediction that larger individuals would be more likely to remain pond residents. This study demonstrates experimentally that migration can be a plastic response influenced by both local density and gender.

Tadpoles of the wood frog, Rana sylvatica were reared in the laboratory at four densities (1, 2, 4, and 8/dish) and at four food levels (1, 2, 4 and 6 multiples of a ration) in a randomized 4—block design for a factorial analysis of variance. Both food and density had significant effects on growth rate and body size at metamorphosis. The length of the larval period was significantly correlated (r=.81) between pairs of larvae reared together but was not significantly associated with either food or density. At low ratios of supply (food level) to demand (density level) body weight increased with food availability. At high supply: demand ratios the excess food caused a pollution effect which reduced growth, body size at metamorphosis and survival. At different densities maximum growth was achieved at different supply: demand ratios. In natural populations, body size decreases with density as if food were in short supply.

Abstract: The intrinsic rate of natural increase, r, is a constant that measures the ability of a popula- tion to grow under a given set of conditions. The hlalthusian parameter, m, is a measure of geno- typic rate of increase. Although the mathematical formulations for r and m are the same, their biological characteristics are different except,in isogenic,populations.,Selection will always,favor genotypes with the highest m under a given set of conditions, but such selection may result in a reduction,of r for that population. The mechanism,by,which,this process occurs,is discussed,and simulated, and it is concluded that evolutionary reductions in r are rnost likely to have occurred under,conditions of density dependence.,It is also suggested that the recent terms r and,K selection have,mixed,ecological parlance,into evolutionary processes in a potentially confusing,manner. Population,ecology,and,population,ge-,tempts,to understand,fully some,of the

One of the great ecologists of the late 20th century passed away on 31 July 2008, at age 90, in Chapel Hill, North Carolina. Nelson George Hairston was born on 16 October 1917 and spent his childhood on his family's plantation, Cooleemee, on the banks of the Yadkin River in Davie County, North Carolina. Even after many years in the upper Midwest, Nelson never lost his genteel Piedmont North Carolina accent and story-telling ability. He was educated at the Virginia Episcopal School, a boarding school in Lynchburg, followed by earning B.S. and M.S. degrees at The University of North Carolina. He enrolled for doctoral study at Northwestern University to study with the “Chicago School” of ecology, as represented by the foundational textbook authors Allee, Emerson, Park, Park, and Schmidt (1949). His doctoral advisor, Orlando Park, pioneered the study of ecological partitioning between nocturnal and diurnal animals. Nelson's work on niche partitioning in plethodontid salamanders in the Southern Appalachians appeared at nearly the same time (1949) as David Lack's classic on Darwin's Finches (1947), and nearly a decade before MacArthur's (1958) work on warblers . Nelson's doctoral study was interrupted by military service during World War II, when he worked in the South Pacific on therapies for malaria. Upon completion of his doctoral studies in 1948, Nelson accepted a position as assistant professor of zoology at the University of Michigan. Despite his eventual fame as an experimental ecologist, he was originally hired as a parasitologist. Throughout his Michigan career, he maintained an active research program in parasitology and epidemiology, especially schistosomiasis on Leyte, the Philippines, and in Egypt for the World Health Organization (Hairston 1962, 1965a, Hairston b, 1973). Largely unknown to the academic community, this work includes some of his most brilliant conceptual and experimental contributions. From this experience Hairston pioneered the application of what we now call “systems ecology” to complex associations between parasites, their hosts, and the environment. Nelson was the senior member of the dynamic trio of ecologists at Michigan with Fred Smith and Larry Slobodkin, who together spawned and cultivated for two decades a vibrant and productive cohort of population and community ecologists. Ann Arbor was home to several other excellent ecologists and evolutionary biologists, but it was Hairston, Smith, and Slobodkin who excited and set the agenda for most of the graduate students. Their paper, HSS (American Naturalist 1960), known colloquially as “the Étude,” a double entendre on the succinct, brilliant piano compositions of Chopin and the frequent designation of Ann Arbor as A2, became a Citation Classic (Current Contents 12 (20):20) because it was an argument other ecologists love to hate and one Nelson never got tired of defending (Hairston 1991). The idea of trophic cascades lives on as a central concept in community ecology in part because of HSS and Hairston's other seminal papers on the patterns and processes that shape ecological communities (Hairston 1959, 1964, Hairston and Hairston 1993, 1997). Nelson especially delighted in his studies of microscopic soil arthropods (Hairston 1951, 1969, Hairston and Byers 1954), because they were animals invisible during sampling and therefore he could have no preconceived biases of their natural community structure. “If p is less than 0.01, you worked too hard.” “If it's not worth doing; it's not worth doing well.” “Some ecologists find mathematics easier than useful scientific work.” “The world IS green.” “Education is the only business where customers want less for their money.” “The problem with a natural experiment is that you don't know what experiment nature ran.” “Reading Fisher is like reading the Book of Revelations.” “I may have been born in North Carolina, but I wasn't born yesterday.” The pedagogical impact of Nelson G. Hairston on dozens of students in that vibrant two decades of the 1960s and 1970s, whether they were formally his own graduate students or not, was immense. In 1974 Hairston accepted the William R. Kenan Professorship in the Department of Zoology (later Biology) at the University of North Carolina. In 1975 this move returned him and Patty to their cultural roots, their summer home in Cashiers, and Highlands Biological Station. The now ready access to his beloved mountains of North Carolina gave Nelson the opportunity to finish his ambitious experiments on the ecological interaction between plethodontid salamander species. This study experimentally tested the hypotheses in his dissertation work of 25 years earlier that interspecific competition set the range limits of these salamander species at their contact zones and shaped the evolution of their competitive abilities (Hairston 1980a, b). In an unprecedented heuristic tour de force Hairston (1973) proudly published all possible outcomes of the planned experiments and their interpretations years before conducting the experiments. The broader implications of this remarkable, large-scale field experiment are nicely summarized in his book Community Ecology and Salamander Guilds 1987. Like Hurlburt (1984), Hairston became increasingly irritated at unsatisfactory experiments in ecological publications, and clarified more rigorous protocols in his powerful 1989 book Ecological Experiments: Purpose, Design, and Execution, a book that is essential reading for any experimentalist. Nelson thrived at UNC, and extended his inspiration in experimental community ecology to another generation of productive students. He was best loved, however, for his tireless enthusiasm for teaching a vertebrate zoology course that at the time was a radical departure from laboratory-constrained courses in comparative vertebrate structure and function. His modern approach to vertebrate natural history, as presented in his 1994 textbook Vertebrate Zoology: an Experimental Field Approach, was dedicated to “the 520 students who, over thirteen years, made it a joy to teach vertebrate field zoology.” These students (and many visiting faculty, including Nelson's enthusiastic successor R. Haven Wiley) traveled with him from Chapel Hill to the Outer Banks “not to bird watch but to study migration” and to the Nantahala and Great Smoky Mountains to experience the kind of fieldwork he did with salamanders. Nelson retired at age 69, but continued to be active in the new Biology Department at UNC and to summer in Cashiers. He received the Eminent Ecologist Award from the Ecological Society of America in 1991 (ESA Bulletin 72(4):240). Nelson is survived by his wife Martha (Patty), five grandchildren, his son Nelson Hairston, Jr., the Frank T. Rhodes Professor of Environmental Science and Senior Associate Dean of Arts and Sciences at Cornell, and Margaret Hairston Searcy, who is married to Bill Searcy, Maytag Professor of Ornithology at the University of Miami. His daughter Martha Hairston Weston predeceased him. He had two full academic careers, one in Ann Arbor, the other in Chapel Hill. In both places he greatly enriched the intellectual tone of his department and was a master model of rigorous science, thinking, careful observation, and field experimentation for hundreds of undergraduates and a long line of graduate students. We thank Nelson G. Hairston, Jr. for helping with the bibliography and commenting on a draft of this resolution. Southern Appalachian Salamanders Malaria Schistosomiasis (= Bilharziasis) and Parasitology Conceptual Ecology Paramecium Studies Natural History Book Reviews

All combinations of 0, 10, 20, and 40 hatchlings of two species of frogs, Hyla femoralis and H. gratiosa, were raised in a replicated experiment in which food and space were controlled. Models of density—dependent growth and metamorphosis can be extended to include the effects of competing species by inclusiion of linear, additive terms. Hyla gratiosa has a strong, negative effect on the rate of metamorphosis and size at metamorphosis of Hyla femoralis. Hyla femoralis has no effect on the survival or mean size at metamorphosis of H. gratiosa, but it does lengthen both the minimum and mean larval period. Interspecific density effects on growth may increase both the risk of predation and the risk of desiccation in natural populations.