Karrin Alstad | Picarro - Academia.edu (original) (raw)

Papers by Karrin Alstad

ABSTRACT We examined the evapotranspiration (ET) of a mixed Oak forest stand located within a woo... more ABSTRACT We examined the evapotranspiration (ET) of a mixed Oak forest stand located within a woodland preserve in NW Ohio using two independent methods. The depth to ground water (DGW) in 2005 to 2007 ranged from 1.35 m at peak recharge (early to mid-May), to below 3.0 m during the driest period near the end of the growing season. The DGW during peak recharge was more shallow in 2007 than the other two years, and while the slopes of the ground water decline during the growing season were similar in 2005 and 2006 (-9 mm and -6 mm per day, respectively), the rate of decline was very steep in the first half of the 2007 growing season (-14 mm per day). Daily ET estimated from the eddy-covariance measurements (EC-ET) averaged 1.6 mm per day during 2005 to 2007. Growing season averaged EC-ET values (May-Oct) ranged from 0 to 5.32 mm per day, being highest in 2007 (2.5 mm per day), and lowest in 2005 (2.2 mm per day). The average growing season temperatures and relative humidity were also highest in 2007 when the highest precipitation and most shallow DGW values were recorded. Finally, weekly EC-ET values were highly correlated with the ET values estimated by the variation in DGW over the same 7 day period (GW-ET). This correlation was highest for 2005 (r=-0.77, p

Estimation of the net flux (F0–Fi)t of CO2 in the valley cross-section below the tower top.

The urban water component of the global freshwater cycle does not use amounts of water comparable... more The urban water component of the global freshwater cycle does not use amounts of water comparable with agriculture; however, cities are hotspots of water use and have water footprints oft en extending orders of magnitude larger than their physical footprints. To bett er understand this water use we propose an urban ecohydrology perspective as a new framework for considering urban water dynamics that emphasizes the combination of hydrological and ecosystem science tools to characterize the fl uxes, constraints, services, and feedbacks between urban ecosystem dynamics and urban ecohydrological processes occurring across a broad range of scales. We present a conceptual model of urban ecohydrology and use as an example the complexities of water supply and demand fl uctuations within the Los Angeles metropolitan region. On the basis of the general model and description of the Los Angeles system we then generate several hypotheses that might diff erentiate the importance of individual water fl uxes and their contribution to ecosystem services based on environmental, socioeconomic, and cultural gradients among cities. T otal water withdrawn for human uses has almost tripled in the last fi ft y years from 1382 km 3 yr −1 in 1950 to 3973 km 3 yr −1 and is projected to further increase to 5235 km 3 yr −1 by 2025 (Clarke and King, 2004), an amount more than nine times the annual fl ow of the Mississippi River (Goudie, 2000). Currently, this withdrawal rate represents more than one-half of the available fresh water supplies feasibly accessible by societies, and this available portion is decreasing (Postel et al., 1996; Vorosmarty and Sahagian, 2000). The amounts of water used in the urban water component of the global freshwater cycle are not comparable with agricultural water use (Gleick, 2003), but cities have water footprints oft en extending orders of magnitude larger than the physical footprint of a city (Luck et al., 2001; Jenerett e et al., 2006b). Population growth trends indicate that by 2030, more than 60% of the world's population is expected to live in cites. Migration from rural to urban

1. Drought-induced mortality and regional dieback of woody vegetation are reported from numerous ... more 1. Drought-induced mortality and regional dieback of woody vegetation are reported from numerous locations around the world. Yet within any one site, predicting which species are most likely to survive global change-type drought is a challenge. 2. We studied the diversity of drought survival traits of a community of 15 woody plant species in a desert-chaparral ecotone. The vegetation was a mix of chaparral and desert shrubs, as well as endemic species that only occur along this margin. This vegetation boundary has large potential for drought-induced mortality because nearly all species are at the edge of their range. 3. Drought survival traits studied were vulnerability to drought-induced xylem cavitation, sapwood capacitance, deciduousness, photosynthetic stems, deep roots, photosynthetic responses to leaf water potential and hydraulic architecture. Drought survival strategies were evaluated as combinations of traits that could be effective in dealing with drought. 4. The large variation in seasonal predawn water potential of leaves and stem xylem ranged from À6Á82 to À0Á29 MPa and À6Á92 to À0Á27 MPa, respectively. The water potential at which photosynthesis ceases ranged from À9Á42 to À3Á44 MPa. Architecture was a determinant of hydraulic traits, with species supporting large leaf area per sapwood area exhibiting high rates of water transport, but also xylem that is vulnerable to drought-induced cavitation. Species with more negative midday leaf water potential during the growing season also showed access to deeper water sources based on hydrogen isotope analysis. 5. Drought survival mechanisms comprised of drought deciduousness, photosynthetic stems, tolerance of low minimum seasonal tissue water potential and vulnerability to drought-induced xylem cavitation thus varied orthogonally among species, and promote a diverse array of drought survival strategies in an arid ecosystem of considerable floristic complexity.

Agricultural Water Management, 2020

The Central Valley of California relies on irrigation for crop production, but water resources, p... more The Central Valley of California relies on irrigation for crop production, but water resources, particularly groundwater, have reached a critical state due to extended drought periods and overuse by irrigated agriculture. The purpose of the Grape Remote sensing Atmospheric Profile and Evapotranspiration eXperiment (GRAPEX) project is to improve efficiency in vineyard irrigation through field measurements and modeling efforts using remote sensing. In this study, we analyze multi-year timeseries of ground-based soil moisture and evapotranspiration (ET) measurements collected during GRAPEX to identify patterns that may inform future irrigation recommendations based on remotely sensed ET. The study focuses on field data collected in two adjacent Pinot noir vineyards near Lodi, CA from 2013 to 2017. The data used for this analysis are reference evapotranspiration (ET ref), actual evapotranspiration (ET a), mean daytime soil water content (SWC) measured to a depth of 90 cm, precipitation, and irrigation. The relationship between SWC and the ratio of ET a /ET ref (used as a soil moisture proxy indicator) changes throughout the spring and summer months due to advancing phenological stages and management practices. In early spring, when the interrow cover crop is the primary source of ET, ET a is strongly correlated with SWC. As the vine canopy grows in, the strong correlation breaks down as the vines begin to access to water beyond the depth of the soil moisture sensors. As the soil profile dries out during the summer, the correlation between ET a and SWC once again emerges as the vines become strongly dependent on irrigation. The dynamic interaction between the upper and lower root zone profile and evaporative demand means that the key to understanding vineyard water status using relatively shallow SWC observations is to use them in conjunction with ET a data, so that when both SWC and ET a timeseries are highly correlated vine water status is well defined. This suggests, delaying the initiation of irrigation during the period of rapid vine growth until a clear relationship between SWC and ET a emerges would both reduce the total amount of water used and give the grower more control over vine growth and grape quality affected by water status.

Xylem vulnerability and hydraulic architecture as determinants of plant drought resistance on a d... more Xylem vulnerability and hydraulic architecture as determinants of plant drought resistance on a desert-shrubland gradient. Louis S. Santiago, Karrin Alstad, Sarah C. Pasquini, Alexandria Pivovaroff, Jeffrey Ambriz and Jenessa ...

Abstract For ecologists interested in measuring the exchange of water and carbon in the soil-plan... more Abstract For ecologists interested in measuring the exchange of water and carbon in the soil-plant-atmosphere continuum, mountainous terrain is largely off limits; airflow patterns in uneven terrain can wreak havoc in the interpretation of vertical fluxes. However, well-developed air drainage systems might be used to advantage. In particular, we postulate that the isotopic composition of CO2 in nocturnal air drainage could be used to monitor vegetation water-use efficiency (WUE) of whole basins. Recent studies show that the ...

The &... more The "Keeling plot" method has proven to be a robust and highly informative measure of ecosystem- atmosphere interactions, particularly with respect to photosynthesis, respiration and water use efficiency of terrestrial ecosystems. Applied over many years and locations, the archive of Keeling plot data is steadily increasing, especially in light of recent coordinated collection efforts and advances in laser-based technologies. However,

Thesis (M.S.)--Colorado State University, 1998. Includes bibliographical references.

"May 2003." Thesis (Ph. D.)--Northern Arizona University, 2003. Includes bibliographica... more "May 2003." Thesis (Ph. D.)--Northern Arizona University, 2003. Includes bibliographical references and abstract.

Tree Physiology, 2007

We compared the carbon isotope composition of ecosystem-respired CO 2 (δ 13 C R ) from 11 forest ... more We compared the carbon isotope composition of ecosystem-respired CO 2 (δ 13 C R ) from 11 forest ecosystems in Canada and the USA and examined differences among forest δ 13 C R responses to seasonal variations in environmental conditions from May to October 2004. Our experimental approach was based on the assumption that variation in δ 13 C R is a good proxy for short-term changes in photosynthetic discrimination and associated shifts in the integrated ecosystem-level intercellular to ambient CO 2 ratio (c i /c a ). We compared δ 13 C R responses for three functional groups: deciduous, boreal and coastal forests. The δ 13 C R values were well predicted for each group and the highest R 2 values determined for the coastal, deciduous and boreal groups were 0.81, 0.80 and 0.56, respectively. Consistent with previous studies, the highest correlations between δ 13 C R and changes in environmental conditions were achieved when the environmental variables were averaged for 2, 3 or 4 days before δ 13 C R sample collection. The relationships between δ 13 C R and environmental conditions were consistent with leaf-level responses, and were most apparent within functional groups, providing support for our approach. However, there were differences among groups in the strength or significance, or both, of the relationships between δ 13 C R and some environmental factors. For example, vapor pressure deficit (VPD) and soil temperature were significant determinants of variation in δ 13 C R in the boreal group, whereas photosynthetic photon flux (PPF) was not; however, in the coastal group, variation in δ 13 C R was strongly correlated with changes in PPF, and there was no significant relationship with VPD. At a single site, comparisons between our δ 13 C R measurements in 2004 and published values suggested the potential application of δ 13 C R measurements to assess year-to-year variation in ecosystem physiological responses to changing environmental conditions, but showed that, in such an analysis, all environmental factors influencing carbon isotope discrimination during photosynthetic gas exchange must be considered.

There is significant uncertainty about the ozone sink properties of the phytosphere due to a comp... more There is significant uncertainty about the ozone sink properties of the phytosphere due to a complexity of interactions and feedbacks with biotic and abiotic factors. Improved understanding of the controls on ozone fluxes is critical to estimating and regulating the total ozone budget. Ozone exchanges of an orange orchard within the city of Riverside, CA were examined using a multiple-scaled approach. We access the carbon, water, and energy budgets at the stand- to leaf- level to elucidate the mechanisms controlling the variability in ozone fluxes of this agro-ecosystem. The two initial goals of the study were 1. To consider variations and controls on the ozone fluxes within the canopy; and, 2. To examine different modeling and scaling approaches for totaling the ozone fluxes of this orchard. Current understanding of the total ozone flux between the atmosphere near ground and the phytosphere (F-total) include consideration of a fraction which is absorbed by vegetation through stomat...

Ecohydrology, 2011

Accurately quantifying evapotranspiration (ET) is essential for modelling regional-scale ecosyste... more Accurately quantifying evapotranspiration (ET) is essential for modelling regional-scale ecosystem water balances. This study assembled an ET data set estimated from eddy flux and sapflow measurements for 13 ecosystems across a large climatic and management gradient from the United States, China, and Australia. Our objectives were to determine the relationships among monthly measured actual ET (ET), calculated FAO-56 grass reference ET (ET o ), measured precipitation (P), and leaf area index (LAI)-one associated key parameter of ecosystem structure. Results showed that the growing season ET from wet forests was generally higher than ET o while those from grasslands or woodlands in the arid and semi-arid regions were lower than ET o . Second, growing season ET was found to be converged to within š10% of P for most of the ecosystems examined. Therefore, our study suggested that soil water storage in the nongrowing season was important in influencing ET and water yield during the growing season. Lastly, monthly LAI, P, and ET o together explained about 85% of the variability of monthly ET. We concluded that the three variables LAI, P, and ET o , which were increasingly available from remote sensing products and weather station networks, could be used for estimating monthly regional ET dynamics with a reasonable accuracy. Such an empirical model has the potential to project the effects of climate and land management on water resources and carbon sequestration when integrated with ecosystem models.

The "Keeling plot&am... more The "Keeling plot" method has proven to be a robust and highly informative measure of ecosystem- atmosphere interactions, particularly with respect to photosynthesis, respiration and water use efficiency of terrestrial ecosystems. Applied over many years and locations, the archive of Keeling plot data is steadily increasing, especially in light of recent coordinated collection efforts and advances in laser-based technologies. However,

ABSTRACT We examined the evapotranspiration (ET) of a mixed Oak forest stand located within a woo... more ABSTRACT We examined the evapotranspiration (ET) of a mixed Oak forest stand located within a woodland preserve in NW Ohio using two independent methods. The depth to ground water (DGW) in 2005 to 2007 ranged from 1.35 m at peak recharge (early to mid-May), to below 3.0 m during the driest period near the end of the growing season. The DGW during peak recharge was more shallow in 2007 than the other two years, and while the slopes of the ground water decline during the growing season were similar in 2005 and 2006 (-9 mm and -6 mm per day, respectively), the rate of decline was very steep in the first half of the 2007 growing season (-14 mm per day). Daily ET estimated from the eddy-covariance measurements (EC-ET) averaged 1.6 mm per day during 2005 to 2007. Growing season averaged EC-ET values (May-Oct) ranged from 0 to 5.32 mm per day, being highest in 2007 (2.5 mm per day), and lowest in 2005 (2.2 mm per day). The average growing season temperatures and relative humidity were also highest in 2007 when the highest precipitation and most shallow DGW values were recorded. Finally, weekly EC-ET values were highly correlated with the ET values estimated by the variation in DGW over the same 7 day period (GW-ET). This correlation was highest for 2005 (r=-0.77, p

Estimation of the net flux (F0–Fi)t of CO2 in the valley cross-section below the tower top.

The urban water component of the global freshwater cycle does not use amounts of water comparable... more The urban water component of the global freshwater cycle does not use amounts of water comparable with agriculture; however, cities are hotspots of water use and have water footprints oft en extending orders of magnitude larger than their physical footprints. To bett er understand this water use we propose an urban ecohydrology perspective as a new framework for considering urban water dynamics that emphasizes the combination of hydrological and ecosystem science tools to characterize the fl uxes, constraints, services, and feedbacks between urban ecosystem dynamics and urban ecohydrological processes occurring across a broad range of scales. We present a conceptual model of urban ecohydrology and use as an example the complexities of water supply and demand fl uctuations within the Los Angeles metropolitan region. On the basis of the general model and description of the Los Angeles system we then generate several hypotheses that might diff erentiate the importance of individual water fl uxes and their contribution to ecosystem services based on environmental, socioeconomic, and cultural gradients among cities. T otal water withdrawn for human uses has almost tripled in the last fi ft y years from 1382 km 3 yr −1 in 1950 to 3973 km 3 yr −1 and is projected to further increase to 5235 km 3 yr −1 by 2025 (Clarke and King, 2004), an amount more than nine times the annual fl ow of the Mississippi River (Goudie, 2000). Currently, this withdrawal rate represents more than one-half of the available fresh water supplies feasibly accessible by societies, and this available portion is decreasing (Postel et al., 1996; Vorosmarty and Sahagian, 2000). The amounts of water used in the urban water component of the global freshwater cycle are not comparable with agricultural water use (Gleick, 2003), but cities have water footprints oft en extending orders of magnitude larger than the physical footprint of a city (Luck et al., 2001; Jenerett e et al., 2006b). Population growth trends indicate that by 2030, more than 60% of the world's population is expected to live in cites. Migration from rural to urban

1. Drought-induced mortality and regional dieback of woody vegetation are reported from numerous ... more 1. Drought-induced mortality and regional dieback of woody vegetation are reported from numerous locations around the world. Yet within any one site, predicting which species are most likely to survive global change-type drought is a challenge. 2. We studied the diversity of drought survival traits of a community of 15 woody plant species in a desert-chaparral ecotone. The vegetation was a mix of chaparral and desert shrubs, as well as endemic species that only occur along this margin. This vegetation boundary has large potential for drought-induced mortality because nearly all species are at the edge of their range. 3. Drought survival traits studied were vulnerability to drought-induced xylem cavitation, sapwood capacitance, deciduousness, photosynthetic stems, deep roots, photosynthetic responses to leaf water potential and hydraulic architecture. Drought survival strategies were evaluated as combinations of traits that could be effective in dealing with drought. 4. The large variation in seasonal predawn water potential of leaves and stem xylem ranged from À6Á82 to À0Á29 MPa and À6Á92 to À0Á27 MPa, respectively. The water potential at which photosynthesis ceases ranged from À9Á42 to À3Á44 MPa. Architecture was a determinant of hydraulic traits, with species supporting large leaf area per sapwood area exhibiting high rates of water transport, but also xylem that is vulnerable to drought-induced cavitation. Species with more negative midday leaf water potential during the growing season also showed access to deeper water sources based on hydrogen isotope analysis. 5. Drought survival mechanisms comprised of drought deciduousness, photosynthetic stems, tolerance of low minimum seasonal tissue water potential and vulnerability to drought-induced xylem cavitation thus varied orthogonally among species, and promote a diverse array of drought survival strategies in an arid ecosystem of considerable floristic complexity.

Agricultural Water Management, 2020

The Central Valley of California relies on irrigation for crop production, but water resources, p... more The Central Valley of California relies on irrigation for crop production, but water resources, particularly groundwater, have reached a critical state due to extended drought periods and overuse by irrigated agriculture. The purpose of the Grape Remote sensing Atmospheric Profile and Evapotranspiration eXperiment (GRAPEX) project is to improve efficiency in vineyard irrigation through field measurements and modeling efforts using remote sensing. In this study, we analyze multi-year timeseries of ground-based soil moisture and evapotranspiration (ET) measurements collected during GRAPEX to identify patterns that may inform future irrigation recommendations based on remotely sensed ET. The study focuses on field data collected in two adjacent Pinot noir vineyards near Lodi, CA from 2013 to 2017. The data used for this analysis are reference evapotranspiration (ET ref), actual evapotranspiration (ET a), mean daytime soil water content (SWC) measured to a depth of 90 cm, precipitation, and irrigation. The relationship between SWC and the ratio of ET a /ET ref (used as a soil moisture proxy indicator) changes throughout the spring and summer months due to advancing phenological stages and management practices. In early spring, when the interrow cover crop is the primary source of ET, ET a is strongly correlated with SWC. As the vine canopy grows in, the strong correlation breaks down as the vines begin to access to water beyond the depth of the soil moisture sensors. As the soil profile dries out during the summer, the correlation between ET a and SWC once again emerges as the vines become strongly dependent on irrigation. The dynamic interaction between the upper and lower root zone profile and evaporative demand means that the key to understanding vineyard water status using relatively shallow SWC observations is to use them in conjunction with ET a data, so that when both SWC and ET a timeseries are highly correlated vine water status is well defined. This suggests, delaying the initiation of irrigation during the period of rapid vine growth until a clear relationship between SWC and ET a emerges would both reduce the total amount of water used and give the grower more control over vine growth and grape quality affected by water status.

Xylem vulnerability and hydraulic architecture as determinants of plant drought resistance on a d... more Xylem vulnerability and hydraulic architecture as determinants of plant drought resistance on a desert-shrubland gradient. Louis S. Santiago, Karrin Alstad, Sarah C. Pasquini, Alexandria Pivovaroff, Jeffrey Ambriz and Jenessa ...

Abstract For ecologists interested in measuring the exchange of water and carbon in the soil-plan... more Abstract For ecologists interested in measuring the exchange of water and carbon in the soil-plant-atmosphere continuum, mountainous terrain is largely off limits; airflow patterns in uneven terrain can wreak havoc in the interpretation of vertical fluxes. However, well-developed air drainage systems might be used to advantage. In particular, we postulate that the isotopic composition of CO2 in nocturnal air drainage could be used to monitor vegetation water-use efficiency (WUE) of whole basins. Recent studies show that the ...

The &... more The "Keeling plot" method has proven to be a robust and highly informative measure of ecosystem- atmosphere interactions, particularly with respect to photosynthesis, respiration and water use efficiency of terrestrial ecosystems. Applied over many years and locations, the archive of Keeling plot data is steadily increasing, especially in light of recent coordinated collection efforts and advances in laser-based technologies. However,

Thesis (M.S.)--Colorado State University, 1998. Includes bibliographical references.

"May 2003." Thesis (Ph. D.)--Northern Arizona University, 2003. Includes bibliographica... more "May 2003." Thesis (Ph. D.)--Northern Arizona University, 2003. Includes bibliographical references and abstract.

Tree Physiology, 2007

We compared the carbon isotope composition of ecosystem-respired CO 2 (δ 13 C R ) from 11 forest ... more We compared the carbon isotope composition of ecosystem-respired CO 2 (δ 13 C R ) from 11 forest ecosystems in Canada and the USA and examined differences among forest δ 13 C R responses to seasonal variations in environmental conditions from May to October 2004. Our experimental approach was based on the assumption that variation in δ 13 C R is a good proxy for short-term changes in photosynthetic discrimination and associated shifts in the integrated ecosystem-level intercellular to ambient CO 2 ratio (c i /c a ). We compared δ 13 C R responses for three functional groups: deciduous, boreal and coastal forests. The δ 13 C R values were well predicted for each group and the highest R 2 values determined for the coastal, deciduous and boreal groups were 0.81, 0.80 and 0.56, respectively. Consistent with previous studies, the highest correlations between δ 13 C R and changes in environmental conditions were achieved when the environmental variables were averaged for 2, 3 or 4 days before δ 13 C R sample collection. The relationships between δ 13 C R and environmental conditions were consistent with leaf-level responses, and were most apparent within functional groups, providing support for our approach. However, there were differences among groups in the strength or significance, or both, of the relationships between δ 13 C R and some environmental factors. For example, vapor pressure deficit (VPD) and soil temperature were significant determinants of variation in δ 13 C R in the boreal group, whereas photosynthetic photon flux (PPF) was not; however, in the coastal group, variation in δ 13 C R was strongly correlated with changes in PPF, and there was no significant relationship with VPD. At a single site, comparisons between our δ 13 C R measurements in 2004 and published values suggested the potential application of δ 13 C R measurements to assess year-to-year variation in ecosystem physiological responses to changing environmental conditions, but showed that, in such an analysis, all environmental factors influencing carbon isotope discrimination during photosynthetic gas exchange must be considered.

There is significant uncertainty about the ozone sink properties of the phytosphere due to a comp... more There is significant uncertainty about the ozone sink properties of the phytosphere due to a complexity of interactions and feedbacks with biotic and abiotic factors. Improved understanding of the controls on ozone fluxes is critical to estimating and regulating the total ozone budget. Ozone exchanges of an orange orchard within the city of Riverside, CA were examined using a multiple-scaled approach. We access the carbon, water, and energy budgets at the stand- to leaf- level to elucidate the mechanisms controlling the variability in ozone fluxes of this agro-ecosystem. The two initial goals of the study were 1. To consider variations and controls on the ozone fluxes within the canopy; and, 2. To examine different modeling and scaling approaches for totaling the ozone fluxes of this orchard. Current understanding of the total ozone flux between the atmosphere near ground and the phytosphere (F-total) include consideration of a fraction which is absorbed by vegetation through stomat...

Ecohydrology, 2011

Accurately quantifying evapotranspiration (ET) is essential for modelling regional-scale ecosyste... more Accurately quantifying evapotranspiration (ET) is essential for modelling regional-scale ecosystem water balances. This study assembled an ET data set estimated from eddy flux and sapflow measurements for 13 ecosystems across a large climatic and management gradient from the United States, China, and Australia. Our objectives were to determine the relationships among monthly measured actual ET (ET), calculated FAO-56 grass reference ET (ET o ), measured precipitation (P), and leaf area index (LAI)-one associated key parameter of ecosystem structure. Results showed that the growing season ET from wet forests was generally higher than ET o while those from grasslands or woodlands in the arid and semi-arid regions were lower than ET o . Second, growing season ET was found to be converged to within š10% of P for most of the ecosystems examined. Therefore, our study suggested that soil water storage in the nongrowing season was important in influencing ET and water yield during the growing season. Lastly, monthly LAI, P, and ET o together explained about 85% of the variability of monthly ET. We concluded that the three variables LAI, P, and ET o , which were increasingly available from remote sensing products and weather station networks, could be used for estimating monthly regional ET dynamics with a reasonable accuracy. Such an empirical model has the potential to project the effects of climate and land management on water resources and carbon sequestration when integrated with ecosystem models.

The "Keeling plot&am... more The "Keeling plot" method has proven to be a robust and highly informative measure of ecosystem- atmosphere interactions, particularly with respect to photosynthesis, respiration and water use efficiency of terrestrial ecosystems. Applied over many years and locations, the archive of Keeling plot data is steadily increasing, especially in light of recent coordinated collection efforts and advances in laser-based technologies. However,