Biology subjects

Katz, D. S.

Publications and source records attributed to Katz, D. S..

3 recordsLinked to original sources

bioRxiv2024

Fungal spore seasons advanced across the US over two decades of climate change

Phenological shifts due to climate change have been extensively studied in plants and animals. Yet, the responses of fungal spores--crucial organisms that play important roles in ecosystems and act as airborne allergens--remain understudied. This knowledge gap in global change biology hinders our understanding of its ecological and public health implications. To bridge this gap, we acquired a long-term (2003 [~] 2022), large-scale (the continental US) dataset of airborne fungal spores collected by the US National Allergy Bureau. We first pre-processed the spore data by gap-filling and smoothing. Afterward, we extracted ten metrics describing the phenology (e.g., start and end of season) and intensity (e.g., peak concentration and integral) of fungal spore seasons. These metrics were derived using two complementary but not mutually exclusive approaches--ecological and public health approaches, defined as percentiles of total spore concentration and allergenic thresholds of spore concentration, respectively. Using linear mixed effects models, we quantified annual temporal shifts in these metrics across the continental US. We revealed a significant advancement in the onset of the spore seasons defined in both ecological (11 days, 95% confidence interval: 0.4 [~] 23 days) and public health (22 days, 6 [~] 38 days) approaches over two decades. Nevertheless, the total spore concentration in an annual cycle and in a spore allergy season tended to decrease over time. The earlier start of the spore season was significantly correlated with climatic variables, such as warmer temperatures and altered precipitations. Overall, our findings suggest possible climate-driven advanced fungal spore seasons, highlighting the importance of climate change mitigation and adaptation in public health decision-making.

ecology↗

bioRxiv2024

Predicting reproductive phenology of wind-pollinated trees via PlanetScope time series

Airborne pollen triggers allergic reactions which result in public health consequences. A better understanding of flowering and pollen phenology could improve airborne pollen predictions and reduce pollen exposure. Data on the timing of flowering and pollen release are needed to improve models of airborne pollen concentrations, but existing in-situ data collection efforts are expensive and spatially sparse. Satellite-based estimates of plant phenology could potentially enable large-scale data collection, but it is difficult to detect the reproductive phenology of wind-pollinated flowers from space. Here, we infer the reproductive phenology of wind-pollinated plants using PlanetScope time series with a spatial resolution of 3 m and a daily revisit cycle, complemented by in-situ flower and pollen observations, leveraging the correlation between vegetative and reproductive phenology. On the individual tree level, we extracted PlanetScope-derived green-up time and validated its correlation to flowering time using flower observations in a national-scale observatory network. Scaling up to the city level, we developed a novel approach to characterize pollen phenology from PlanetScope-derived vegetative phenology, by optimizing two tuning parameters: the threshold of green-up or green-down and the time lag between green-up/down and flowering. We applied this method to seven cities in the US and seven key wind-pollinated tree genera, calibrated by measurements of airborne pollen concentrations. Our method characterized pollen phenology accurately, not only in-sample (Spearman correlation: 0.751, nRMSE: 13.5%) but also out-of-sample (Spearman correlation: 0.691, nRMSE: 14.5%). Using the calibrated model, we further mapped the pollen phenology landscape within cities, showing intra-urban heterogeneity. Using high spatiotemporal resolution remote sensing, our novel approach enables us to infer the flowering and pollen phenology of wind-pollinated plant taxa on a large scale and a fine resolution, including areas with limited prior in-situ flower and pollen observations. The use of PlanetScope time series therefore holds promise for developing process-based pollen models and targeted public health strategies to mitigate the impact of allergenic pollen exposure.

ecology↗

bioRxiv2023

The potential effects of tree planting on allergenic pollen production in New York City

AO_SCPLOWBSTRACTC_SCPLOWTree selection decisions affect urban pollen production but the overall importance of tree planting to airborne pollen concentrations remains poorly understood. A synthesis of existing data and available literature could inform tree -planting decisions and potentially help reduce future airborne pollen concentrations. This is especially relevant for the many cities that are considering tree planting campaigns, such as New York City. Here, I examine which allergenically -important tree taxa could be most influenced by municipal tree selectio n decisions in New York City by comparing tree species abundance from a representative plot-based city-wide tree survey with a street tree inventory. I then estimate pollen production from several allergenic tree taxa by combining these tree datasets with allometric equations of pollen production as a function of tree size. Pollen production is also compared to several years of airborne pollen measurements. The potential effect of a proposed planting campaign is estimated over time by combining growth rate equations with pollen production equations. Several tree genera are especially important producers of allergenic pollen in New York City, including Quercus, Platanus, Morus, and Betula; these taxa also comprise 71% of airborne pollen measured and 93% of estimated pollen production (107 quadrillion pollen grains ; however pollen production could not be estimated for all taxa). Platanus x acerifolia is predominantly a street tree, indicating that previous municipal planting decisions have resulted in its current abundance (it accounts for 34% of total street tree basal area and has an estimated annual pollen production of almost 30 quadrillion grains) and will determine its future abundance. In contrast, Morus and Betula are uncommon as street trees, indicating that municipal tree planting campaigns are unlikely to substantially affect their pollen production rates in NYC. Quercus was the largest estimated producer of pollen in NYC (62 quadrillion pollen grains) and accounted for almost 25% of airborne pollen co llected, but its very high abundance outside of street trees suggest that the relative effect of planting trees in this genus will be relatively small. Overall, this study demonstrates how tree planting decisions can have important and long-lasting consequences for allergenic pollen production in certain circumstances, suggesting that pollen allergenicity should be considered in future tree selection decisions.

ecology↗