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The tenure-and-promotion policy for university faculty often lacks clarity even if it has existed for many decades. Frequently shrouded in generalities and open to any number of interpretations, such a policy can create a stressful environment for pretenured faculty. The author explains how members of the department of Kinesiology, Recreation and Sport at Western Kentucky University revised their tenure-and-promotion policy to include less ambiguity and more definitive guidelines. [ABSTRACT FROM AUTHOR]

Presents a study which tested for adaptive differentiation between two populations of the North American annual Impatiens capensis from adjacent sites known to differ in selection on plasticity to density. Population differentiation in plasticity to density and site; Environment-dependent differences between populations; Results of analysis of covariance to test for effects of site differences at low density.

Studies the environment-specific genetic constraints on the evolution of plastic responses to density. Related studies on the pattern of genetic variation in plasticity; Methodology; Results and discussion.

Studies the value and possible costs of plasticity of life-history traits to crowding and foliage shade in the annual plant Arabidopsis thaliana. Related studies on phenotypic plasticity; Methodology; Results and discussion.

In this study, we investigated students 'attitudes toward physical activity (PA) when including a required PA component in a university-required personal wellness class. The study included (a) an experimental group of students enrolled in a personal wellness course in which there was a required PA requirement and (b) a control group of students enrolled in a personal wellness course in which there was no PA requirement. Subjects were tested using the Corbin Attitude Test. The students in the experimental group were exposed to an additional PA requirement in which they were to exercise at least twice per week at a perceived exertion level of 4 or above on the modified 1 to 10 scale. Students in the control group were only required to complete the university-required personal wellness course, which did not include a required PA component. A repeated measures ANOVA was used to determine if adding the PA component had an effect on students' attitudes and perceptions toward their personal health and to check for significance between gender and attitude toward physical activity. The analysis of the data showed no significant gain or decline in attitude for either group, suggesting that although specific required PA does not significantly improve attitude, it does not hurt it either. It could be surmised from this study and similar studies that choice of activity is the most important factor for improving attitude toward PA. [ABSTRACT FROM AUTHOR]

The purpose of this study was to examine pre-service teachers' (PTs) ability to deliver feedback, which has been used as a process variable in identifying teacher-effectiveness and an established NASPE standard for beginning teachers. These questions guided the study: 1. Will overall feedback interactions delivered by PTs reach 45 per video? 2. What is the nature of the feedback interactions provided by physical education pre-service teachers? The participants in this study were nine college-aged PTs enrolled in a required Elementary Physical Education Practicum and Methods course taught twice per week to students in Grades 3 to 6 and videotaped four times. Analysis of the videotapes was performed using the Studiocode analysis program. PTs surpassed the 45 feedback interactions by delivering an average of 56 feedback interactions per lesson. Delivery of corrective feedback was reduced from 34.78 interactions in pretest to 32 interactions during posttest. Congruent feedback increased from pretest to posttest from 6.22 to 8.55 interactions, respectively. Individual interactions were reduced from pretest (39.55) to posttest (26.55), and small group interactions increased from pretest (17.55) to posttest (21.66). Analysis of videotapes should continue to be integrated during field experiences to augment PTs pedagogical skills. Future research should be focused on the effects of specific feedback protocols on PTs delivery of feedback during field experiences. [ABSTRACT FROM AUTHOR]

Abstract: The controls on uptake and release of CO2 by tropical rainforests, and the responses to a changing climate, are major uncertainties in global climate change models. Eddy-covariance measurements potentially provide detailed data on CO2 exchange and responses to the environment in these forests, but accurate estimates of the net ecosystem exchange of CO2 (NEE) and ecosystem respiration (R eco) require careful analysis of data representativity, treatment of data gaps, and correction for systematic errors. This study uses the comprehensive data from our study site in an old-growth tropical rainforest near Santarem, Brazil, to examine the biases in NEE and R eco potentially associated with the two most important sources of systematic error in Eddy-covariance data: lost nighttime flux and missing canopy storage measurements. We present multiple estimates for the net carbon balance and R eco at our site, including the conventional “u* filter”, a detailed bottom-up budget for respiration, estimates by similarity with 222Rn, and an independent estimate of respiration by extrapolation of daytime Eddy flux data to zero light. Eddy-covariance measurements between 2002 and 2006 showed a mean net ecosystem carbon loss of 0.25±0.04μmolm−2 s−1, with a mean respiration rate of 8.60±0.11μmolm−2 s−1 at our site. We found that lost nocturnal flux can potentially introduce significant bias into these results. We develop robust approaches to correct for these biases, showing that, where appropriate, a site-specific u* threshold can be used to avoid systematic bias in estimates of carbon exchange. Because of the presence of gaps in the data and the day–night asymmetry between storage and turbulence, inclusion of canopy storage is essential to accurate assessments of NEE. We found that short-term measurements of storage may be adequate to accurately model storage for use in obtaining ecosystem carbon balance, at sites where storage is not routinely measured. The analytical framework utilized in this study can be applied to other Eddy-covariance sites to help correct and validate measurements of the carbon cycle and its components. [Copyright &y& Elsevier]

Satellite-based observations indicate that seasonal patterns in canopy greenness and productivity in the Amazon are negatively correlated with precipitation, with increased greenness occurring during the dry months. Flux tower measurements indicate that the canopy greening that occurs during the dry season is associated with increases in net ecosystem productivity (NEP) and evapotranspiration (ET). Land surface and terrestrial biosphere model simulations for the region have predicted the opposite of these observed patterns, with significant declines in greenness, NEP, and ET during the dry season. In this study, we address this issue mainly by developing an empirically constrained, light-controlled phenology submodel within the Ecosystem Demography model version 2 ( ED2). The constrained ED2 model with a suite of field observations shows markedly improved predictions of seasonal ecosystem dynamics, more accurately capturing the observed patterns of seasonality in water, carbon, and litter fluxes seen at the Tapajos National Forest, Brazil (2.86° S, 54.96° W). Long-term simulations indicate that this light-controlled phenology increases the resilience of Amazon forest NEP to interannual variability in climate forcing. [ABSTRACT FROM AUTHOR]

The allocation and cycling of carbon (C) within forests is an important component of the biospheric C cycle, but is particularly understudied within tropical forests. We synthesise reported and unpublished results from three lowland rainforest sites in Amazonia (in the regions of Manaus, Tapajós and Caxiuanã), all major sites of the Large-Scale Biosphere–Atmosphere Programme (LBA). We attempt a comprehensive synthesis of the C stocks, nutrient status and, particularly, the allocation and internal C dynamics of all three sites. The calculated net primary productivities (NPP) are 10.1±1.4 Mg C ha−1 yr−1 (Manaus), 14.4±1.3 Mg C ha−1 yr−1 (Tapajós) and 10.0±1.2 Mg C ha−1 yr−1 (Caxiuanã). All errors bars report standard errors. Soil and leaf nutrient analyses indicate that Tapajós has significantly more plant-available phosphorus and calcium. Autotrophic respiration at all three sites (14.9–21.4 Mg C ha yr−1) is more challenging to measure, with the largest component and greatest source of uncertainty being leaf dark respiration. Comparison of measured soil respiration with that predicted from C cycling measurements provides an independent constraint. It shows general good agreement at all three sites, with perhaps some evidence for measured soil respiration being less than expected. Twenty to thirty percent of fixed C is allocated belowground. Comparison of gross primary productivity (GPP), derived from ecosystem flux measurements with that derived from component studies (NPP plus autotrophic respiration) provides an additional crosscheck. The two approaches are in good agreement, giving increased confidence in both approaches to estimating GPP. The ecosystem carbon-use efficiency (CUEs), the ratio of NPP to GPP, is similar at Manaus (0.34±0.10) and Caxiuanã (0.32±0.07), but may be higher at Tapajós (0.49±0.16), although the difference is not significant. Old growth or infertile tropical forests may have low CUE compared with recently disturbed and/or fertile forests. [ABSTRACT FROM AUTHOR]

Woody debris (WD) is an important component of forest C budgets, both as a C reservoir and source of CO2 to the atmosphere. We used an infrared gas analyzer and closed dynamic chamber to measure CO2 efflux from downed coarse WD (CWD; diameter≥7.5 cm) and fine WD (FWD; 7.5 cm>diameter≥2 cm) to assess respiration in a selectively logged forest and a maturing forest (control site) in the northeastern USA. We developed two linear regression models to predict WD respiration: one based on WD temperature, moisture, and size ( R 2=0.57), and the other on decay class and air temperature ( R 2=0.32). WD respiration (0.28±0.09 Mg C ha−1 year−1) contributed only ≈2% of total ecosystem respiration (12.3±0.7 Mg C ha−1 year−1, 1999–2003), but net C flux from CWD accounted for up to 30% of net ecosystem exchange in the maturing forest. C flux from CWD on the logged site increased modestly, from 0.61±0.29 Mg C ha−1 year−1 prior to logging to 0.77±0.23 Mg C ha−1 year−1 after logging, reflecting increased CWD stocks. FWD biomass and associated respiration flux were ≈7 times and ≈5 times greater, respectively, in the logged site than the control site. The net C flux associated with CWD, including inputs and respiratory outputs, was 0.35±0.19 Mg C ha−1 year−1 (net C sink) in the control site and −0.30±0.30 Mg C ha−1 year−1 (net C source) in the logged site. We infer that accumulation of WD may represent a small net C sink in maturing northern hardwood forests. Disturbance, such as selective logging, can enlarge the WD pool, increasing the net C flux from the WD pool to the atmosphere and potentially causing it to become a net C source. [ABSTRACT FROM AUTHOR]

The net ecosystem exchange of carbon dioxide was measured by eddy covariance methods for 3 years in two old-growth forest sites near Santarém, Brazil. Carbon was lost in the wet season and gained in the dry season, which was opposite to the seasonal cycles of both tree growth and model predictions. The 3-year average carbon loss was 1.3 (confidence interval: 0.0 to 2.0) megagrams of carbon per hectare per year. Biometrie observations confirmed the net loss but imply that it is a transient effect of recent disturbance superimposed on long-term balance. Given that episodic disturbances are characteristic of old-growth forests, it is likely that carbon sequestration is lower than has been inferred from recent eddy covariance studies at undisturbed sites. [ABSTRACT FROM AUTHOR]

Examines the factors controlling atmospheric carbon dioxide sequestration in a mid-latitude forest in the United States. Average net uptake of carbon dioxide of a 60 to 80-year-old forest; Importance of weather and seasonal climate in regulation of seasonal and inter-annual fluctuations of carbon uptake; Impact of historical land-use and disturbance on carbon sequestration.