Explore the vast range of titles available.

\"This book presents recent advancements in positive psychology, specifically its application across broad areas of current interest. Chapters include submissions from various international authors in the field and cover discussion and presentation of relevant research, theories, and applications. The volume covers topics such as CBT, Psychotherapy, Coaching, Workplaces, Aging, Education, Leadership, Emotion, Interventions, Measurement, Technology, Design, Health, Relationships, Experiences, Communities. With the growing interest in the applications of positive psychology across diverse fields within psychology and beyond, this book will make a worthwhile contribution to the field. It will also fill the current need for a volume that highlights specifically the various recent advancements in positive psychology into diverse fields and as such will be of benefit to a wide range of professionals, including psychologists, educators, clinicians, therapists, and many others.\" -- Publisher's website.

Controls on Arctic vegetation physiology have been linked to microscale (1–100 m) topography and landscape position, yet drivers may change under future climates as temperature, active-layer thickness, and nutrient limitations are removed or altered. Focusing on the cosmopolitan dwarf birch (Betula glandusa), physiological metrics were measured over two field campaigns at Trail Valley Creek, NWT, Canada, and linked to tasked and archived multispectral imagery to investigate drivers. Relative humidity was ~31.1% on 25 June 2023, and increased to 45.6% on 29 June 2023, which corresponded to heightened physiological activity of stomatal conductance and light-adapted fluorescence (gsm: 0.118 vs. 0.165 μmol m−2 s−1, Fs: 129.29 vs. 178.42). Normalized difference vegetation index of AVIRIS, Sentinel 2, and SkySat were negligibly correlated to dwarf birch physiological activity, but moderately correlated to dwarf birch height and active-layer thickness. Random forest variable importance revealed that environmental factors and field-measured active-layer thickness ranked higher than remote sensing metrics in explaining physiological activity regardless of the field campaign. Overall, these findings suggest that microscale variation can influence dwarf birch physiological activity, yet microscale effects are overwritten by environmental conditions that may hinder fine-scale space-based monitoring of Arctic vegetation physiological dynamics.

Forest canopies create buffered understory microclimates that differ markedly from adjacent open-area reference conditions. However, how this buffering effect varies near the forest edge, especially between different forest types and seasons, remains poorly understood. In particular, the spatiotemporal dynamics of maximum cooling and the spatial extent of edge influence across forest types remain under-quantified. This study quantified monthly maximum cooling intensity (MCI) and distance of edge influence (DEI) using transect-based in situ air-temperature monitoring at three natural forest sites in southwestern China that span a temperate coniferous forest (CF), a subtropical evergreen broadleaved forest (SF), and a tropical forest (TF). Air temperature was measured at 1.5 m height from the forest edge to 99.5 m into the interior and was paired with a continuously recorded open reference. DEI varied strongly through the year and among sites, ranging from 18 to 77 m in CF, from 13 to 65 m in SF, and from 17 to 59 m in TF. DEI reached its early-summer minimum in May in CF and in June in both SF and TF, while annual DEI was 82 m in CF, 72 m in SF, and 56 m in TF. Within the corresponding interior zones, extreme cooling was strongest in TF (MCI = −8.2°C) and weakest in CF (MCI = −5.8°C). These site-level patterns indicate that both the intensity and spatial reach of extreme cooling are seasonally dynamic along a climatic gradient, which supports edge-aware microclimate mapping, evaluation of interior habitat connectivity, and conservation planning in fragmented forests under climate change.

Root exudates accumulate as a radial gradient around the root, yet little is known about variability at the individual root level. Vertical gradients in soil properties are hypothesized to cause greater accumulation of exudates in deeper soil through hindering diffusion, increasing sorption, and decreasing mineralization. To this end, a single root exudation model coupling concentration specific exudation and depth dependent soil properties was developed. The model was parameterized for a peatland ecosystem to explore deposition to the methanogen community. Numerical experiments indicate that exudates accumulated to a greater extent in deeper soil, albeit the effect was solute specific. Rhizosphere size for glucose doubled between the 10 and 80 cm depths, while the rhizoplane concentration was 1.23 times higher. Root influx of glucose increased from 1.431 to 1.758 nmol cm−1 hr−1, representing a recapture efficiency gain of 15.74% (i.e., 69.06% versus 84.8%). Driven by increased root influx, overall net exudation rates of select sugars and amino acids varied by a factor two. Model sensitivity analysis revealed that soil depth and root influx capability are key determinants of the rhizoplane concentration and subsequently net exudation, which determines whether effluxed compounds escape the root oxic shell and are available to the methanogen community.

Light availability (LAv) dictates a variety of biological and ecological processes across a range of spatiotemporal scales. Quantifying the spatial pattern of LAv in three‐dimensional (3D) space can promote the understanding of microclimates that are critical to fine‐scale species distribution. However, there is still a lack of tools that are robust to evaluate spatiotemporal heterogeneity of LAv in forests. Here, we propose the Forest Light Analyzer python package (FLApy), an open‐source computational tool designed for the analysis of intra‐forest LAv variation across multiple spatial scales. FLApy is freely invoked by Python, facilitating the processing of LiDAR point cloud data into a 3D data container constructed by voxels, as well as traversal calculations related to the LAv regime by high performance synthetic hemispherical algorithm. Furthermore, FLApy incorporates 37 indicators, enabling users to expediently export and visualize LAv patterns and the evaluation of heterogeneity of LAv at two scales (voxel scale and 3D‐cluster scale) for a range of fine‐scale ecological study purposes. To validate the efficacy of the FLApy, we employed a simulated point cloud dataset that simulates forests (varying in canopy closure). Furthermore, to evaluate real world forest, we executed the standard workflow of FLApy utilizing drone‐derived data from three subtropical evergreen broad‐leaved forest dynamics plots within the Ailao Mountain Reserve. Our findings underscore that a series of indices derived from FLApy provide a robust characterization of light availability heterogeneity within diverse forest settings. Additionally, when juxtaposed with conventional monitoring techniques, the metrics offered by FLApy demonstrated better generality in our field assessments. FLApy offers ecologists a solution for rapid quantification of understory light 3D‐regimes across multiple scales, addressing the disparity between traditional manual approaches and the precision required for contemporary ecological studies. Moreover, FLApy provides robust support for the establishment and expansion of heterogeneity indices based on 3D micro‐environments, enhancing our understanding of the largely uncharted 3D structural patterns. Anticipated outcomes suggest that FLApy will enhance our knowledge concerning the intra‐forest climatic conditions into a 3D context, proving pivotal in the delineation of microhabitats and the development of detailed 3D‐scale species distribution models.

Efforts to monitor terrestrial decomposition dynamics at broad spatial scales are hampered by the lack of a cost-effective and scalable means to track the decomposition process. Recent advances in remote sensing have enabled the simulation of litter spectra throughout decomposition for grasses in general, yet unique decomposition pathways are hypothesized to create subtly different litter spectral signatures with unique ecosystem functional significance. The objectives of this study were to improve spectra–decomposition linkages and thereby enable the more comprehensive monitoring of ecosystem processes such as nutrient and carbon cycles. Using close-range hyperspectral imaging, litter spectra and multiple decomposition metrics were concurrently monitored in four classes of naturally decayed litter under four decomposition treatments. The first principal component accounted for approximately 94% of spectral variation in the close-range imagery and was attributed to the progression of decomposition. Decomposition-induced spectral changes were moderately correlated with the leaf carbon to nitrogen ratio (R2 = 0.52) and sodium hydroxide extractables (R2 = 0.45) but had no correlation with carbon dioxide flux. Temperature and humidity strongly influenced the decomposition process but did not influence spectral variability or the patterns of surface decomposition. The outcome of the study is that litter spectra are linked to important metrics of decomposition and thus remote sensing could be utilized to assess decomposition dynamics and the implications for nutrient recycling at broad spatial scales. A secondary study outcome is the need to resolve methodological challenges related to inducing unique decomposition pathways in a lab environment. Improving decomposition treatments that mimic real-world conditions of temperature, humidity, insolation, and the decomposer community will enable an improved understanding of the impacts of climatic change, which are expected to strongly affect microbially mediated decomposition.

Aims Plant roots control many important interactions in the wetland anoxic zone such as carbon deposition, gas exchange, and nutrient dynamics, yet few studies document the vertical depth distribution of fine roots which mediates these interactions. Methods Excavated root systems of a wetland sedge and shrub were scanned. Utilizing Root System Analyzer, normalized root length per 5 cm depth interval were quantified for 10 samples of each species. Utilizing bootstrapping, root length per depth interval for each root class was fitted to a density distribution function and matched to water table depth. Results Vertical root length distributions varied by root class, with shrub fine roots constrained to a narrow depth range. Between 1999 and 2010, the interface with the anoxic zone can vary by a factor of four between wet and dry years. Conclusions Compared to estimates of root vertical distribution based on biomass, this study indicates a considerably higher portion of the fine roots occur in anoxic soil. Accurately quantifying the spatial distribution of the fine roots, root tips, and other sites associated with exudation is crucial for determining the strength of root-methanogen interactions.

A large range of labile organic compounds are secreted by roots into the soil, which inevitably leads to changes in nutrient availability and C cycling. Little is known about root exudation variability among species, or at the individual root level, hampering estimates of total C deposition. Environmental controls are believed to influence root exudation at the single root scale, yet are rarely accounted for. Quantifying exudation heterogeneities within the root system permits more accurate upscaling to the whole plant and landscape level, provided the sites of exudation and belowground biomass are well quantified. Root exudate composition was characterized in two model organisms - Eriophorum vaginatum and Rhododendron groenlandicum utilizing localized sampling of root segments. E. vaginatum roots were distinguished into three classes by age, and R. groenlandicum into four classes by fine root abundance and root diameter. Considerable variations in the total efflux, as well as the composition of exudates, was documented at both the species and root class level, confirming that exudation is not homogenous within the root system. Existing root biomass data has little correlation with the vertical gradients of exudation. Whole plant root systems were excavated and digitally mapped at sufficient detail to explicitly distinguish the depth distribution of the roots associated with exudation. Measurements of the normalized root length fraction per depth interval were tested against a variety of density distribution models to infer a suitable function to represent roots for upscaling a single root to the landscape scale. The abundance of key species such E. vaginatum that deposit C directly into the anoxic zone are poorly mapped in peatlands. A new detection methodology, based on phenological timing and the spectral contrast of decomposing litter, was investigated utilizing an expanded version of PROSAIL. Close range imagery indicated the calibrated model was capable of quantifying decaying monocot litter as a unique class, which bodes well for detection at the landscape scale. The studies presented in this thesis document root exudation rates and root distribution data necessary to conduct a simple upscaling from the single root to the landscape level. Collectively, they permit the C flow via the exudation pathway to be estimated, with consideration for vertical gradients that partition exudation into the oxic and anoxic zone.

This thesis investigated multispectral detection of the invasive floating macrophyte, European Frog-bit, using Quickbird imagery and fuzzy image classification. To determine if the spectral signature of European Frog-bit were separable from other wetland vegetation, a species level land cover classification was conducted on a 6km section of the South Nation River in Ontario, Canada. Supervised and unsupervised imagery classification approaches were evaluated using the fuzzy classifiers, Fuzzy Segmentation for Object Based Image Classification (FS) and Fuzzy C-Means (FCM). Both approaches were sufficiently robust to detect European Frog-bit. User's and producer's accuracies for the European Frog-bit class were 81.0% and 77.9% for the FS classifier and 63.5% and 73.0% for the FCM classifier. These accuracies indicated that the spectral signature of EFB was sufficiently different to permit detection and separation from other wetland vegetation and fuzzy image classifiers were capable of detecting EFB in Quickbird imagery.

Host–symbiont relationships are ubiquitous in nature, yet evolutionary and ecological processes that shape these intricate associations are often poorly understood. All orders of birds engage in symbioses with feather mites, which are ectosymbiotic arthropods that spend their entire life on hosts. Due to their permanent obligatory association with hosts, limited dispersal and primarily vertical transmission, we hypothesized that the cospeciation between feather mites and hosts within one avian family (Parulidae) would be perfect (strict cospeciation). We assessed cophylogenetic patterns and tested for congruence between species in two confamiliar feather mite genera (Proctophyllodidae: Proctophyllodes, Amerodectes) found on 13 species of migratory warblers (and one other closely related migratory species) in the eastern United States. Based on COI sequence data, we found three Proctophyllodes lineages and six Amerodectes lineages. Distance- and event-based cophylogenetic analyses suggested different cophylogenetic trajectories of the two mite genera, and although some associations were significant, there was little overall evidence supporting strict cospeciation. Host switching is likely responsible for incongruent phylogenies. In one case, we documented prairie warblers Setophaga discolor harboring two mite species of the same genus. Most interestingly, we found strong evidence that host ecology may influence the likelihood of host switching occurring. For example, we documented relatively distantly related ground-nesting hosts (ovenbird Seiurus aurocapilla and Kentucky warbler Geothlypis formosa) sharing a single mite species, while other birds are shrub/canopy or cavity nesters. Overall, our results suggest that cospeciation is not the case for feather mites and parulid hosts at this fine phylogenetic scale, and raise the question if cospeciation applies for other symbiotic systems involving hosts that have complex life histories. We also provide preliminary evidence that incorporating host ecological traits into cophylogenetic analyses may be useful for understanding how symbiotic systems have evolved.