This dissertation investigated the practicality and expediency of applying remote sensing data fusion products to the analysis of dryland vegetation phenology. The objective of the first study was to verify the quality of the output products of the spatial and temporal adaptive reflectance fusion method (STARFM) over the dryland Arizona study site. Synthetic 30 m resolution images were generated from Landsat-5 Thematic Mapper (TM) data and a range of 500 m Moderate Resolution Imaging Spectroradiometer (MODIS) surface reflectance datasets and assessed via correlation analysis with temporally coincident Landsat-5 imagery. The accuracy of the results (0.61 < R2 < 0.94) justified subsequent use of STARFM data in this environment, particularly when the imagery were generated from Nadir Bi-directional Reflectance Factor (BRDF)-Adjusted Reflectance (NBAR) MODIS datasets. The primary objective of the second study was to assess whether synthetic Landsat data could contribute meaningful information to the phenological analyses of a range of dryland vegetation classes. Start-of-season (SOS) and date of peak greenness phenology metrics were calculated for each STARFM and MODIS pixel on the basis of enhanced vegetation index (EVI) and normalized difference vegetation index (NDVI) time series over a single growing season. The variability of each metric was calculated for all STARFM pixels within 500 m MODIS extents. Colorado Plateau Pinyon Juniper displayed high amounts of temporal and spatial variability that justified the use of STARFM data, while the benefit to the remaining classes depended on the specific vegetation index and phenology metric. The third study expanded the STARFM time series to five years (2005-2009) to examine the influence of site characteristics and climatic conditions on dryland ponderosa pine (Pinus ponderosa) forest phenological patterns. The results showed that elevation and slope controlled the variability of peak timing across years, with lower elevations and shallower slopes linked to higher levels of variability. During drought conditions, the number of site variables that controlled the timing and variability of vegetation peak increased. / Ph. D.

A phenological model of gypsy moth egg development is proposed that distinguishes three phases of egg development, prediapause, diapause and postdiapause. A technique of measuring respiration rates of individual eggs was developed and respiration rate was used as a physiological variable to distinguish the phases. The pattern of respiration rate provided strong evidence in support of three distinct developmental phases. Respiration rate developed embryos declined sharply as prediapause was entered and rose sharply when diapause was completed. When the effect of age on respiration rate was removed, temperature had a uniform effect on respiration rate throughout the egg stage. A 10°C decrease in temperature caused an approximate 0.4 fold decrease in respiration rate, indicating that eggs in diapause are as equally responsive to temperature as egg in a nondiapause phase. Developmental rate in prediapause was strongly temperature-dependent, and the relationship was described by a non-linear function. Prediapause duration was approximately 13 days at 31°C. The depletion of stored triglycerides was strongly linked to the completion of prediapause. Developmental rate in postdiapause was found to be temperature- and age-dependent. Developmental response to temperature was relatively weak and linear at the onset of postdiapause. As postdiapause advanced, the response became stronger and non-linear. The temperature- and age-dependent developmental response was fully described by the temperature-dependent developmental response at the onset of postdiapause, and by a temperature-dependent rate change parameter. / Ph. D.

Monitoring and understanding plant phenology is becoming an increasingly important way to identify and model global changes in vegetation life cycle events. Although numerous studies have used synoptically sensed data to study phenological patterns at the continental and global scale, relatively few have focused on characterizing the land surface phenology of specific ecosystems. Mountain environments provide excellent examples of how variations in topography, elevation, solar radiation, temperature, and spatial location affect vegetation phenology. High elevation biomes cover twenty percent of the Earth's land surface and provide essential resources to both the human and non-human population. These areas experience limited resource availability for plant growth, development, and reproduction, and are one of the first ecosystems to reflect the harmful impact of climate change. Despite this, the phenology of mountain ecosystems has historically been understudied due to the rough and variable terrain and inaccessibility of the area. Here, we use two MODIS/Terra satellite 16-day products, Vegetation Index and Nadir BRDF Adjusted Reflectance, to assess start of season (SOS) for the 2007 calendar year. Independent data for elevation, slope, aspect, solar radiation, and temperature as well as longitude and latitude were then related to the SOS output. Based on the results of these analyses, we found that SOS can be predicted with a significant R² (0.55-0.64) for each individual zone as well as the entire western mountain range. While both elevation and latitude have significant influences on the timing of SOS for all six study areas. When examined at the regional scale and accounting for aspect, SOS follows closely with Hopkins' findings in regard to both elevation and latitude. / Master of Science

The spotted lanternfly, Lycorma delicatula (White) (Hemiptera: Fulgoridae), is a new invasive insect from Asia that is currently spreading in the Mid-Atlantic region of the US, where it has become a pest of economic concern for many industries in their invaded range. The purpose of this research was to document L. delicatula phenology in Virginia, their feeding impact to trees, and to test a rearing protocol in quarantine laboratory conditions. First, using field plots and weekly observational surveys, L. delicatula phenology was documented in 2019 and 2020 in Winchester, Virginia. I showed that L. delicatula were active from late April into November for each sampling year, and that the timing of life stage events varied only slightly between years. I also calculated cumulative average growing degree days for each life stage event using a lower developmental threshold of 10°C. Additionally, I confirmed that the host range of L. delicatula narrows as they progress through development. These results will help growers and land managers develop integrated pest management plans targeting L. delicatula. Second, dendrochronological methods were used to quantify L. delicatula feeding injury to Ailanthus altissima (Miller) Swingle (Sapindales: Simaroubaceae), Juglans nigra L. (Fagales: Juglandaceae), and Liriodendron tulipifera L. (Magnoliales: Magnoliaceae). Two sites in Pennsylvania that have experienced high populations and heavy feeding pressure from L. delicatula since 2016 were used to collect tree cores for analysis. I found evidence suggesting L. delicatula is capable of reducing the growth of A. altissima, but did not find the same evidence in the wood of the other tree species tested. Additionally, I found evidence that systemic insecticide treatments may reduce or prevent damage to A. altissima fed on by L. delicatula. Additional dendrochronological studies on the damage inflicted by L. delicatula feeding could shed light on the long-term impact of this new invasive tree pest. Lastly, a protocol for rearing L. delicatula was tested inside Virginia Tech's Insect Quarantine Laboratory. Three different cuttings of A. altissima (apical meristems, epicormic shoots, and field collected foliage) were tested to determine the best food source for L. delicatula in quarantine laboratory conditions. Overall, I did not find a significant difference between food treatments, however a greater proportion of third instars developed into fourth instars in the apical meristem treatment. I suggest future L. delicatula rearing research include the use of potted plants and/or multiple species. Though I had low success in rearing adult L. delicatula to produce egg masses, this method may prove useful for rearing early instars from eggs or sustaining field collected specimens for short durations. Research expanding our knowledge of L. delicatula will help us reach our goal of more effectively managing this pest species in the future. / Master of Science in Life Sciences / The spotted lanternfly, Lycorma delicatula (White), is a new invasive pest species impacting the eastern and northeastern regions of the United States. This insect uses its straw-like mouth parts to feed on the sap of many different plants including fruit trees, grapes, and several important ornamental and timber trees. Though they do not bite or sting, feeding can result in wilting, the growth of sooty mold, and sometimes plant mortality, making them an economic and nuisance pest in their invaded range. This research primarily focused on studying the timing of the spotted lanternfly's life cycle, feeding impact to trees, and a method for raising them in the laboratory for research purposes. The life-cycle of the spotted lanternfly was documented over two growing seasons in Winchester, VA and the timing of each life stage was shown to be similar between years. Additionally, it was confirmed that the spotted lanternfly feeds on fewer host species as it develops into an adult. Tree-ring analysis was used to identify spotted lanternfly feeding injury to tree-of-heaven, black walnut, and tulip poplar. I found evidence suggesting spotted lanternfly feeding can cause reduced growth in tree-of-heaven, but did not find similar evidence in the other species tested. A laboratory colony of spotted lanternflies would prove beneficial for additional research on this insect. I tested three different types of branches cut from the tree-of-heaven to identify the best food source for spotted lanternfly in laboratory conditions. The findings of this research will help develop pest management strategies to reduce the impact of this new pest in the US.

Terrestrial ecosystems provide a substantial carbon sink that helps mitigate climate change, sequestering roughly 30% of anthropogenic carbon emissions annually. However, the long-term future of this sink is not well understood. In this dissertation, I use satellite remote sensing, in-situ measurements, and models to improve understanding of the nature and magnitude of spatial and temporal variation in the primary productivity of Eastern Deciduous Forests of the United States. In my first research chapter, I use remote sensing to model to the phenology of two key variables that control forest productivity: leaf area index (LAI) and the fraction of absorbed photosynthetically active radiation (fAPAR). Results show that the relationship between remotely sensed vegetation indices and both LAI and fAPAR is strongly influenced by systematic variation in near infrared reflectance arising from seasonal changes in canopy shadow fraction that are independent of physical changes in forest canopy properties. In my second research chapter, I use estimates of gross primary production (GPP) derived from eddy covariance measurements at four temperate deciduous sites to model the phenology and controls on light use efficiency (LUE) within and across sites. Results show that multiple modes of variation in incoming radiation dominate daily and seasonal variation in LUE, and provide a refined basis for understanding how variability in environmental controls affect LUE and how the strength of these drivers change throughout the growing season. In my third research chapter, I use the long-term record of Landsat imagery, in-situ phenological observations, and estimates of GPP derived from eddy covariance measurements at two temperate deciduous forest sites to investigate how phenology controls interannual variability in GPP at these sites. Results demonstrate that phenology metrics derived from remote sensing are consistent with in-situ measurements, and that interaction between the timing of growing season anomalies and incoming radiation explains a significant proportion of interannual variation in GPP. Taken together, results from this dissertation demonstrate how variation in phenology and LUE control variation in deciduous forest productivity, which is essential for reducing uncertainty in how future climate changes will impact the carbon budget of deciduous forest ecosystems.

The pine bark adelgid, Pineus strobi (Hemiptera: Adelgidae) is a native herbivore of eastern white pine, Pinus strobus (Pinales: Pinaceae), in eastern North America. It is a sessile insect that settles on P. strobus and inserts its stylet bundle to feed on the tree’s phloem. Although P. strobi is not considered a serious pest, it shares its range with the invasive hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae). Predators introduced as biological control agents of A. tsugae interact with P. strobi and its native predators, including Laricobius rubidus LeConte (Coleoptera: Derodontidae). Prior to this study, little work had been done to document the phenology or predators of P. strobi, particularly in its southern range. In the present study, the phenology of P. strobi is reported in southwestern Virginia. Patterns in overwintering population dynamics varied notably from those described from this species’ northern range. The number of annual generations could not be measured due to overlap following two distinct spring generations. Adult body size varied seasonally and was greatest in the spring. Variation between observations from the northern and southern ranges of P. strobi indicate phenological plasticity that informs biological control efforts and offers insight into implication of climatic effects on population dynamics of this and related species. Arthropod predators associated with P. strobi in forests of southwest Virginia were collected during a two-year survey. Morphology and DNA barcoding were used for identification. Species of predators found included: Laricobius rubidus (Coleoptera: Derodontidae), a native adelgid specialist, and two species from the dipteran family Chamaemyiidae, Leucopis piniperda Malloch and L. argenticollis Zetterstedt, which are adelgid specialists. Members of the families Cecidomyiidae, Coccinellidae, Chrysopidae, Hemerobiidae, and Syrphidae were also recovered. Most diverse were the Cecidomyiidae, with 15 different species inferred from their DNA barcodes. Additional work was performed to quantify supercooling points of L. rubidus collected from November – December 2016. These will be compared to those of other Laricobius species in a parallel study. Knowledge of this predator complex is beneficial to describing P. strobi ecology, and also with regard to potential biological control of invasive adelgids in the same region. / Ph. D. / The pine bark adelgid, Pineus strobi (Hemiptera: Adelgidae) is a native herbivore of eastern white pine, Pinus strobus (Pinales: Pinaceae), in eastern North America. It is a sedentary insect that settles on P. strobus bark, branches, and needle bases where it inserts its mouthparts to feed on the tree’s fluid nutrients. Even when P. strobi populations are dense, it does not harm the tree and is not considered a serious pest. It does, however, share its range with the invasive hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae). Predators introduced as biological control agents of A. tsugae also interact with P. strobi and its native predators, including Laricobius rubidus LeConte (Coleoptera: Derodontidae). Prior to the current study, little work had been done to document the natural history or predators of P. strobi, particularly in its southern range, both of which are relevant to the management of other invasive adelgid species found there. In the present study, the natural history of P. strobi is reported in southwestern Virginia. Patterns in the frequencies of various life stages present during the winter varied notably from those described from this species’ northern range. The number of annual generations could not be accurately measured due to the degree of overlap following two distinct spring generations. Adult body size varied seasonally and was greatest in the spring. Variation between observations from the northern and southern ranges of P. strobi indicates that its natural history can vary with the climate, which not only informs biological control efforts, but also offers insight into implication of climatic effects on the population dynamics of this and related species. This study also describes arthropod predators associated with the pine bark adelgid in forests of southwest Virginia found during a two-year survey. Physical characteristics and molecular techniques were used in identification. Species of predators found include: Laricobius rubidus (Coleoptera: Derodontidae), a native adelgid specialist, and two species from the family Chamaemyiidae, Leucopis piniperda Malloch (Diptera: Chamaemyiidae) and L. argenticollis Zetterstedt (Diptera: Chamaemyiidae), which are known adelgid specialists. Members of the families Cecidomyiidae, Coccinellidae, Chrysopidae, Hemerobiidae, and Syrphidae were also recovered. Most diverse were the Cecidomyiidae, with 15 different species genetically identified. Additional work was performed to quantify the bodily freezing points of L. rubidus collected from November – December 2016. These will be compared to those of related biological control agents in a parallel study. Knowledge of this predator complex is beneficial to describing P. strobi ecology, and also with regard to potential biological control of other invasive adelgids in the same region.

Yeung, Fai Fai. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 212-243). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstract (English) --- p.iv / Abstract (Chinese) --- p.x / Contents --- p.xiv / List of Tables --- p.xxii / List of Figures --- p.xxiv / Chapter Chapter 1 --- General Introduction --- p.1 / Chapter I.1 --- General Ideal and Background on Seasonality and Phenology --- p.1 / Chapter I.I.1 --- Seasonality Study of Terrestrial Plant --- p.2 / Chapter I.I.2 --- Study on Seasonality of Marine Algae --- p.3 / Chapter I.2 --- Life History and Seasonality of Sargassum spp --- p.4 / Chapter I.2.1 --- Why Study Sargassum seasonality --- p.5 / Chapter I.2.2 --- Spatial and Temporal Variations in Seasonality of Sargassum spp --- p.6 / Chapter I.2.2.1 --- Differences in seasonality based on locality --- p.7 / Chapter I.2.2.2 --- Interspecific differences in seasonality --- p.7 / Chapter I.2.2.3 --- Intra-specific differences in seasonality --- p.8 / Chapter I.2.3 --- Studies on Seasonality of Sargassum spp. in Hong Kong --- p.9 / Chapter I.3 --- Photosynthesis of Seaweeds --- p.11 / Chapter I.3.1 --- Photosynthesis - Ecophysiological Indicator for Seasonality --- p.11 / Chapter I.3.2 --- Photosynthesis in Different Parts of Seaweeds --- p.13 / Chapter I.3.3 --- New Methodology to Study Photosynthesis --- p.15 / Chapter I.4. --- Scope and Significance of this Thesis Research --- p.16 / Chapter I.4.1 --- General Objectives --- p.17 / Chapter I.4.2 --- Study Organisms --- p.17 / Chapter I.4.2.1 --- Sargassum hemiphyllum (Turner) C Agardh --- p.18 / Chapter I.4.2.1 --- Sargassum siliquastrum (Turner) C Agardh --- p.18 / Chapter I.4.3 --- Study Site --- p.19 / Chapter I.4.3.1 --- Lung Lok Shui (LLS) --- p.19 / Chapter I.4.3.2 --- Lung Yue Tsui (LYT) --- p.19 / Chapter I.4.3.3 --- Lo Fu Ngan (LFN； --- p.20 / Chapter I.4.3.4 --- Lung Ha Wan (LHW) --- p.21 / Chapter I.4.3.5 --- Clear Water Bay (CWB) --- p.21 / Chapter I.4.3.6 --- Tai Tam Wan --- p.21 / Chapter I.4.3.6.1 --- Tai Tam Wan (rock shore) (TTW(rs)) --- p.21 / Chapter I.4.3.6.2 --- Tai Tam Wan (sea school) (TTW (ss)) --- p.21 / Chapter I.5 --- Organization Chart --- p.22 / Chapter Chapter 2 --- Comparative Seasonality of Sargassum siliquastrum and S hemiphyllum in Hong Kong S.A.R --- p.35 / Chapter II.1 --- Introduction --- p.35 / Chapter II.2 --- Materials and Methods --- p.39 / Chapter II.2.1 --- Study Sites --- p.39 / Chapter II.2.2 --- Seasonal Variation in Size and Reproductive Status of Sargassum Plants --- p.39 / Chapter II.2.3 --- "Seasonal Variation in Growth Rates, Population Structures and Densities" --- p.42 / Chapter II.2.4 --- Comparisons between Populations of Sargassum spp --- p.43 / Chapter II.2.5 --- Seasonal Changes in Environmental Parameters --- p.44 / Chapter II.2.6 --- Statistical Analysis --- p.45 / Chapter II.3 --- Results --- p.46 / Chapter II.3.1 --- Seasonality of S. siliquastrum along the Latitudinal Gradient from North to South of Hong Kong --- p.46 / Chapter II.3.1.1 --- Seasonal variation of mean thallus length --- p.46 / Chapter II.3.1.2 --- Seasonality in reproduction --- p.47 / Chapter II. 3.1.3 --- Growth rates --- p.49 / Chapter II.3.1.4 --- Seasonal variations in mean density --- p.50 / Chapter II. 3.1.5 --- Population structure --- p.51 / Chapter II.3.2 --- Seasonality of S. siliquastrum along the Vertical Gradient of Different Depths --- p.56 / Chapter II.3.2.1 --- Seasonal variation of mean thallus length --- p.56 / Chapter II. 3.2.2 --- Seasonality of reproduction --- p.56 / Chapter II.3.2.3 --- Growth rates --- p.57 / Chapter II.3.2.4 --- Seasonal variations in mean density --- p.58 / Chapter II.3.2.5 --- Population Structure --- p.59 / Chapter II.3.3 --- Seasonality of S. hemiphyllum along the Latitudinal Gradient from North to South of Hong Kong --- p.63 / Chapter II. 3.3.1 --- Seasonal variation of mean thallus length --- p.63 / Chapter II. 3.3.2 --- Percentage of reproductive plants --- p.63 / Chapter II.3.3.3 --- Growth rates --- p.64 / Chapter II.3.4 --- Comparison of Seasonality between S siliquastrum and S. hemiphyllum --- p.64 / Chapter II.3.5 --- Comparison of Environmental Parameters among Sites --- p.66 / Chapter II.4 --- Discussion --- p.69 / Chapter II.4.1 --- Inter-specific Comparison on Sargassum phenology --- p.69 / Chapter II.4.2 --- Intra-specific Comparison on Sargassum phenology --- p.73 / Chapter II.4.2.1 --- Comparison along regional scale (> 100kms) geographical range --- p.73 / Chapter II. 4.2.2 --- Comparison along meso-scale (< 100kms) geographical range --- p.77 / Chapter II. 4.2.2.1 --- Comparison along meso-scale latitudinal gradient 一 S. siliquastrum --- p.78 / Chapter II.4.2.2.2 --- Comparison along meso-scale latitudinal gradient - S. hemiphyllum --- p.82 / Chapter II. 4.2.2.3 --- Comparison along vertical depth gradient - S. siliquastrum --- p.87 / Chapter II.5 --- Summary --- p.91 / Chapter Chapter 3 --- Photosynthetic activities of Sargassum siliquastrum and S hemiphyllum in Hong Kong S.A.R --- p.125 / Chapter III.l. --- Introduction --- p.125 / Chapter III.2. --- Materials and Methods --- p.128 / Chapter III.2.1 --- Seasonal Variation in Photosynthetic Activities of Sargassum spp. (Field Monitoring) --- p.128 / Chapter III.2.2 --- Seasonal Variation in Photosynthetic Activities of Sargassum spp. (Laboratory Measurement) --- p.130 / Chapter III.3 --- Results --- p.131 / Chapter III.3.1 --- Initial Preliminary Testing on Sampling Size for PAM Measurement --- p.131 / Chapter III.3.2 --- Seasonal Variations of Effective Quantum Yield (Field Monitoring) --- p.131 / Chapter III. 3.2.1 --- Intra-specific comparison along latitudinal gradient from north to south of Hong Kong 一 S siliquastrum --- p.131 / Chapter III. 3.2.2 --- Intra-specific comparison along latitudinal gradient from north to south of Hong Kong 一 S hemiphyllum --- p.134 / Chapter III.3.2.3 --- Intra-specific comparison along vertical depth gradient - S. siliquastrum --- p.136 / Chapter III.3.3 --- Seasonal Variations of Maximum Quantum Yield (Laboratory Measurement) and Comparative Photosynthesis of Different Parts of Sargassum spp --- p.137 / Chapter III.4 --- Discussion --- p.139 / Chapter III.4.1 --- Seasonal Photosynthetic Performances of S siliquastrum and S. hemiphyllum --- p.139 / Chapter III.4.2 --- Different level of Photosynthesis in Various Parts of Sargassum spp --- p.146 / Chapter III.4.3 --- Comparative Photosynthesis from Different Depths --- p.153 / Chapter III.5. --- Summary --- p.155 / Chapter Chapter 4 --- Transplantation Experiment --- p.172 / Chapter IV.l. --- Introduction --- p.172 / Chapter VI.2. --- Materials and Methods --- p.174 / Chapter IV.2.1 --- Reciprocal Transplantation for S. siliquastrum --- p.174 / Chapter IV.2.2 --- Reciprocal Transplantation for S. hemiphyllum --- p.176 / Chapter VI.3. --- Results --- p.178 / Chapter IV.3.1 --- Reciprocal Transplantation for S. siliquastrum --- p.178 / Chapter IV.3.1.1 --- Mean thallus length --- p.178 / Chapter IV.3.1.2 --- Percentage of reproductive plants --- p.181 / Chapter IV.3.1.3 --- Photosynthetic effective quantum yield --- p.182 / Chapter IV.3.1.4 --- Survivorship --- p.183 / Chapter IV.3.2 --- Reciprocal Transplantation for S. hemiphyllum --- p.184 / Chapter IV.3.2. 1 --- Mean thallus length --- p.184 / Chapter IV.3.2.2 --- Percentage of reproductive plants --- p.185 / Chapter IV.3.2.3 --- Photosynthetic effective quantum yield --- p.186 / Chapter IV.3.2.4 --- Survivorship --- p.187 / Chapter IV.4 --- Discussion --- p.187 / Chapter IV.4.1 --- Transplantation Experiment for S. siliquastrum --- p.188 / Chapter IV.4.2 --- Transplantation Experiment for S. hemiphyllum --- p.192 / Chapter IV.5 --- Summary --- p.196 / Chapter Chapter 5 --- Summary and Conclusion --- p.204 / References --- p.212

The phenology of the three exotic pine bark beetles present in South Africa was determined in the south-western Cape Province. Results from weekly trapping of adult beetles using trap-logs over a period of five years showed that the different species had activity peaks at different times of the year. Hylastes angustatus was the most consistent with 95% of the beetles captured in September and October. The Orthotomicus erosus activity peak was more variable but always occurred in the summer months (October to February) when 84% of the beetles were captured. Hylurgus ligniperda was the most variable, being found in every month of the year, although an autumn peak representing 37% of the beetles occurred in April/May. Activity peaks of each species coincided with distinct climatic conditions. Buried and partially-buried pine logs placed vertically in the soil to simulate roots and stems of seedlings were used to determine the colonisation sites of the three bark beetle species. Ninety-eight percent of O. erosus beetles were found in the protruding parts of the logs while 86% of H. ligniperda beetles were found mainly below soil level. H. angustatus were intermediate, entering the logs at or just below the soil interface but colonising mainly the buried parts in which 64% of the beetles were found. Both H. angustatus and H. ligniperda were able to detect and colonise logs buried horizontally at depths of 400mm, but O. erosus beetles were unable to do so. For adequate protection of seedlings from bark beetles, insecticide should be applied to both stems and roots. The phenology of the indigenous pine needle feeders Oosomus varius (Curculionidae) and Prasoidea sericea (Chrysomelidae) was determined by counting, at weekly intervals, the number of beetles present on 10 young pine trees. The O. varius activity peak occurred in August where 42% of all beetles were active, with 87% of the beetles present in July, August and September. P. sericea also had their activity peak in August when 60% of all beetles were active, but with August and September alone accounting for 87% of the beetles. The occurrence of the activity peaks was consistent each year over the five-year study period. This information facilitates the correct timing of prophylactic insecticide sprays.

Subtropical deforestation in Latin America is thought to be driven by demand for agricultural land, particularly to grow soybeans. However, existing remote sensing methods that can differentiate crop types to verify this hypothesis require high spatial or spectral resolution data, or extensive ground truth information to develop training sites, none of which are freely available for much of the world. I developed a new method of crop classification based on the phenological signatures of crops extracted from multi-temporal MODIS vegetation indices. I tested and refined this method using the USDA Cropland Data Layer from Kansas, USA as a reference. I then applied the method to classify crop types for a study site in Pellegrini, Santiago Del Estero, Argentina. The results show that this method is unable to effectively separate summer crops in Pellegrini, but can differentiate summer crops and non-summer crops. Unmet assumptions about agricultural practices are primarily responsible for the ineffective summer crop classification, underlining the need for researchers to have a complete understanding of ground conditions when designing a remote sensing analysis.

Phenology is an integrative science that comprises the study of recurring biological activities or events. In an era of rapidly changing climate, the relationship between the timing of those events and environmental cues such as temperature, snowmelt, water availability, or day length are of particular interest. This article provides an overview of the observer-based plant phenology sampling conducted by the U.S. National Ecological Observatory Network (NEON), the resulting data, and the rationale behind the design. Trained technicians will conduct regular in situ observations of plant phenology at all terrestrial NEON sites for the 30-yr life of the observatory. Standardized and coordinated data across the network of sites can be used to quantify the direction and magnitude of the relationships between phenology and environmental forcings, as well as the degree to which these relationships vary among sites, among species, among phenophases, and through time. Vegetation at NEON sites will also be monitored with tower-based cameras, satellite remote sensing, and annual high-resolution airborne remote sensing. Ground-based measurements can be used to calibrate and improve satellite-derived phenometrics. NEON's phenology monitoring design is complementary to existing phenology research efforts and citizen science initiatives throughout the world and will produce interoperable data. By collocating plant phenology observations with a suite of additional meteorological, biophysical, and ecological measurements (e.g., climate, carbon flux, plant productivity, population dynamics of consumers) at 47 terrestrial sites, the NEON design will enable continental-scale inference about the status, trends, causes, and ecological consequences of phenological change.