Species richness generally promotes ecosystem productivity, although the shape of the relationship varies and remains the subject of debate. One reason for this uncertainty lies in the multitude of methodological approaches to sampling biodiversity and productivity, some of which can be subjective. Remote sensing offers new, objective ways of assessing productivity and biodiversity. In this study, we tested the species richness-productivity relationship using a common remote sensing index, the Normalized Difference Vegetation Index (NDVI), as a measure of productivity in experimental prairie grassland plots (Cedar Creek). Our study spanned a growing season (May to October, 2014) to evaluate dynamic changes in the NDVI-species richness relationship through time and in relation to environmental variables and phenology. We show that NDVI, which is strongly associated with vegetation percent cover and biomass, is related to biodiversity for this prairie site, but it is also strongly influenced by other factors, including canopy growth stage, short-term water stress and shifting flowering patterns. Remarkably, the NDVI-biodiversity correlation peaked at mid-season, a period of warm, dry conditions and anthesis, when NDVI reached a local minimum. These findings confirm a positive, but dynamic, productivity-diversity relationship and highlight the benefit of optical remote sensing as an objective and non-invasive tool for assessing diversity-productivity relationships.

Photoprotective pigments, like those involved in the xanthophyll cycle, help plants avoid oxidative damage caused by excess radiation. This study aims to characterize a spectrum of strategies used to cope with light stress by a diverse group of prairie plants at Cedar Creek Ecosystem Science Reserve (East Bethel, MN). We find that concentrations of photosynthetic and photoprotective pigments are highly correlated with one another and with other physiological traits across species and over time, and tend to be phylogenetically conserved. During a period of water limitation, plots dominated by species with constitutively low pigment concentrations showed a greater decline in mean reflectance and photochemical reflectance index, a reflectance-based indicator of photoprotective physiology, possibly due to alterations in canopy structure. Our findings suggest two contrasting strategies for withstanding light stress: (1) Using photoprotective pigments to dissipate excess energy, and (2) altering canopy structure to minimize absorbance of excess radiation.

The goal of this research was to evaluate the effects of learning mathematics with a born-digital interactive e-book and Digital Teaching Platform (DTP) on various aspects of a meaningful learning experience. DTP is a real-time learning system designed for one-to-one 21 st century environment. To that effect, the learning experience and perceptions of a class of sixth grade students and their teacher were evaluated. Research was conducted using a qualitative-constructivist approach. Twenty two (22) students, who study at one school, were observed and interviewed. These students learn mathematics with an advanced e-book, on the Digital Teaching Platform of "Time to Know". Analysis of the observations and the interviews led to the identification of three themes relating to aspects of learning with a born-digital interactive e-book: (1) Independent learning with collaboration, (2) Aspects of the technological environment and their implications and (3) The role of the teacher. Findings show that learning mathematics with a born-digital interactive e-book is characterized by a sense of relevance, learner involvement, a sense of value for the learner, independent learning with collaboration and a positive learning experience. It seems that learning with an e-book promotes a meaningful learning experience. The teacher perceives her role as the designer and the manager of the learning process. Most of the students think that it is easier to teach with an e-book and say that the teacher is no longer the only source of knowledge. 