UMBC Geography and Environmental Systems Department

Permanent URI for this collectionhttp://hdl.handle.net/11603/39

A hallmark of the Department of Geography & Environmental Systems is its broadly integrative nature, drawing on the expertise of faculty with diverse backgrounds but with a common mission. Research interests among current regular departmental faculty span a broad range of topics in earth systems science, ecosystem science, human geography and urban geography, and human dimensions of global change, with application of geospatial technology to research questions across all areas of interest. Despite the diversity of research and teaching interests, there is a common focus on the importance of coupled natural and human systems and on landscape pattern in relation to human activities and their environmental consequences, and we see this as a broad programmatic thrust for our graduate degree offerings. Research based in the Department of Geography and Environmental Systems involves interdisciplinary collaborative work of local, regional and international scope.

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Multi?Scale Spatial Effects Determine Nest Success in Small Urban Forest Patches
(Wiley, 2025-2-28) Ohad, Paris; Studds, Colin
Urban development and resulting habitat fragmentation affect species populations and inter-specific relationships. While urban ecology research often focuses on species distribution and abundance in habitat fragments, less is known about how urban environments affect reproductive success. Here, we show that factors driving songbird nest success in small urban forest patches vary with landscape-specific edge effects and Light Detection and Ranging (LiDAR) derived vegetation structure. Nest success declined within 30 meters of patch edge, but only in more developed urban landscapes. In addition, nest success increased along two fundamental axes of vegetation structure in urban fragments: overstory density and number of ground-to-canopy gaps. Hence, results indicate that forest fragmentation can generate sufficient variation in ecological conditions to create heterogeneity in edge effects and vegetation structure even across the limited urban development gradient. These findings expand to our understanding of fragmentation effects beyond the traditional rural-developed paradigm.
Abolishing Poverty: Toward Pluriverse Futures and Politics
(University of Georgia Press, 2023) Lawson, Victoria; Elwood, Sarah; Mendoza, Yolanda González; Reddy, Chandan
Abolishing Poverty argues for a project of relationality that refuses the whiteness of liberal poverty studies and instead centers critiques of the poverty relation and political futures disavowed under liberal governance. In disrupting poverty thinking, the author collective opens space for diverse frameworks for understanding impoverishment and articulating antiracist knowledges and political visions. The book explores new infrastructures of possibilities and political solidarities rooted in accountable relations to each other and from flights to the future that animate diverse communities.This book is boundary and genre crossing, with broad appeal to scholars of such disciplines as human geography, ethnic studies, decolonial theory, and feminist studies. As a volume, the work is unique in its primary field of human geography in the form of its making, its collective authorship, and its investigation of politics that abolish poverty thinking and engage in activism against the poverty relation produced through settler colonialism, heteropatriarchy, white supremacy, and capitalist exploitation.
Ecological and developmental history impacts the equitable distribution of services
(Wiley, 2025-03-11) Darling, Lindsay E.; Rollinson, Christine R.; Fahey, Robert T.; Morzillo, Anita T.; Johnson, Lea R.; Baker, Matthew; Aronson, Myla FJ; Hardiman, Brady S.
The ecological and developmental history of the Chicago, Illinois, region has affected the current distribution of forests therein. These same factors, along with systemic and long-lasting racial segregation, have shaped the distribution of the urban populations that benefit from the ecosystem services provided by urban forests. This study demonstrates that forest patch history is related to forest attributes like tree species composition, tree density, canopy height, and structural heterogeneity—all of which are important predictors of a forest's ability to provide ecosystem services. However, this effect of forest history was only seen in forest cores, as forest edges were similar regardless of patch history. We also found that forests in minoritized communities tended to be less able to support high levels of ecosystem services. This research indicates that, when improving green equity, it is important to consider the variable capacity of forests to provide ecosystem services.
The airborne LUnar Spectral Irradiance (air-LUSI) Mission
(NASA, 2018-10-08) Turpie, Kevin; Brown, Steve; Woodward, John; Maxwell, Steve; Larason, Thomas; Zarobila, Clarence; Grantham, Steve; Gadsden, Andrew; Cataford, Andrew; Stone, Tom
The airborne LUnar Spectral Irradiance (air-LUSI) mission is a NASA Airborne Instrument Technology Transition (AITT) project. The goal of the AITT program is to mature airborne instruments from the demonstration phase to science-capable instruments.The USGS RObotic Lunar Observatory (ROLO) model represents the most precise knowledge of lunar spectral irradiance and is used frequently as a relative calibration standard for Earth observation by space-borne sensors (Keiffer and Stone, 2005). However, apparent phase-dependent biases in ROLO limits its application for absolute radiometric calibration. The objective of air-LUSI is to provide NASA a capability to improve ROLO by measuring exo-atmospheric lunar spectral irradiance with unprecedented accuracy. Careful characterization of the Moon from above the atmosphere will make it a stable and consistent SI-traceable absolute calibration reference. This could revolutionize lunar calibration for some Earth observing satellites and would be especially beneficial to ocean color missions. Because of the high sensitivity of aquatic remote sensing to calibration (Turpie et al., 2015), improvement of lunar calibration could directly affect upcoming PACE and JPSS (VIIRS) missions, and retrospectively for the SeaWiFS, EOS (MODIS), and S-NPP (VIIRS) data records.
Refusal, Service, and Collective Agency: The Everyday and Quiet Resistance of Black Southern Activists
(University of Georgia Press, 2023) McCutcheon, Pricilla; Kohl, Ellen
Abolishing Poverty argues for a project of relationality that refuses the whiteness of liberal poverty studies and instead centers critiques of the poverty relation and political futures disavowed under liberal governance. In disrupting poverty thinking, the author collective opens space for diverse frameworks for understanding impoverishment and articulating antiracist knowledges and political visions. The book explores new infrastructures of possibilities and political solidarities rooted in accountable relations to each other and from flights to the future that animate diverse communities.This book is boundary and genre crossing, with broad appeal to scholars of such disciplines as human geography, ethnic studies, decolonial theory, and feminist studies. As a volume, the work is unique in its primary field of human geography in the form of its making, its collective authorship, and its investigation of politics that abolish poverty thinking and engage in activism against the poverty relation produced through settler colonialism, heteropatriarchy, white supremacy, and capitalist exploitation.
Relationality as Resistance: Dismantling Colonialism and Racial Capitalism
(University of Georgia Press, 2023) Gonzalez Mendoza, Yolanda
Abolishing Poverty argues for a project of relationality that refuses the whiteness of liberal poverty studies and instead centers critiques of the poverty relation and political futures disavowed under liberal governance. In disrupting poverty thinking, the author collective opens space for diverse frameworks for understanding impoverishment and articulating antiracist knowledges and political visions. The book explores new infrastructures of possibilities and political solidarities rooted in accountable relations to each other and from flights to the future that animate diverse communities.This book is boundary and genre crossing, with broad appeal to scholars of such disciplines as human geography, ethnic studies, decolonial theory, and feminist studies. As a volume, the work is unique in its primary field of human geography in the form of its making, its collective authorship, and its investigation of politics that abolish poverty thinking and engage in activism against the poverty relation produced through settler colonialism, heteropatriarchy, white supremacy, and capitalist exploitation.
The influence of urban and agricultural landscape contexts on forest diversity and structure across ecoregions
(Wiley, 2025-02-25) Schmit, John Paul; Johnson, Lea R.; Baker, Matthew; Darling, Lindsay; Fahey, Robert; Locke, Dexter H.; Morzillo, Anita T.; Sonti, Nancy F.; Trammell, Tara L. E.; Aronson, Myla F. J.; Johnson, Michelle L.
Forest patches in urban landscapes make outsized contributions to biodiversity, ecosystem function, and human health and well-being. However, urbanization can alter environmental conditions that underpin forest health. Most studies of forest health in urban landscapes have focused on few forest patches across a single metropolitan region, and synthesis is needed to understand broader patterns. We assessed variation among measures of forest health across land cover gradients and ecoregions by determining (1) whether the degree of urban, agricultural, and forested land surrounding a forest patch was reflected in differences in tree community composition, diversity, and structure and (2) whether these differences were consistent across ecoregions. We synthesized data from 17 observational studies (3334 plots) and remotely sensed land cover (1-km buffer) across four metropolitan regions (Baltimore?Washington DC, Chicago, New York City, and Philadelphia) spanning five ecoregions of the eastern deciduous forest of North America. Land cover surrounding forest patches differed among ecoregions, and forests were surrounded by heterogeneous land cover even in the most urbanized areas. Patterns of tree species composition and forest structure reflected landscape context. Forest patches surrounded by high canopy cover had greater or equal tree species diversity, density, basal area, and diversity of tree sizes relative to patches surrounded by highly agricultural or highly impervious landscapes. In contrast, there was little difference in structure and diversity between forests in highly agricultural and impervious settings. Tree species composition varied among ecoregions, yet tree community assemblages of forests in intensively urbanized areas were consistently distinct from those of forests in other contexts. Forest patches in the most urban and most agricultural landscapes shared predominantly native species communities and were characterized by low tree species diversity, basal area, and size class diversity, as well as high non-native tree abundance, highlighting commonalities among these intensive anthropogenic landscapes. These results point to both common challenges to forest health and common opportunities for forest stewardship in urban and agricultural landscapes.
Rainfall Frequency Analysis Based on Long-Term High-Resolution Radar Rainfall Fields: Spatial Heterogeneities and Temporal Nonstationarities
(AGU, 2024) Smith, James A.; Baeck, Mary Lynn; Miller, Andrew; Claggett, Elijah L.
Rainfall frequency analysis methods are developed and implemented based on high-resolution radar rainfall data sets, with the Baltimore metropolitan area serving as the principal study region. Analyses focus on spatial heterogeneities and time trends in sub-daily rainfall extremes. The 22-year radar rainfall data set for the Baltimore study region combines reflectivity-based rainfall fields during the period from 2000 to 2011 and polarimetric rainfall fields for the period from 2012 to 2021. Rainfall frequency analyses are based on non-stationary formulations of peaks-over-threshold and annual peak methods. Increasing trends in short-duration rainfall extremes are inferred from both peaks-over-threshold and annual peak analyses for the period from 2000 to 2021. There are pronounced spatial gradients in short-duration rainfall extremes over the study region, with peak values of rainfall between Baltimore City and Chesapeake Bay. Spatial gradients in 100-year, 1 hr rainfall over 20 km length scale are comparable to time trends over 20 years. Rainfall analyses address the broad challenge of assessing changing properties of short-duration rainfall in urban regions. Analyses of high-resolution rainfall fields show that sub-daily rainfall extremes are only weakly related to daily extremes, pointing to difficulties in inferring climatological properties of sub-daily rainfall from daily rainfall analyses. Changing measurement properties are a key challenge for application of radar rainfall data sets to detection of time trends. Mean field bias correction of radar rainfall fields using rain gauge observations is an important tool for improving radar rainfall fields and provides a useful tool for addressing problems associated with changing radar measurement properties.
Catchment-Scale Rain Garden Effectiveness and its Spatiotemporal Factors: A Case Study in Columbia, Maryland
(2024-01-01) Daniels, Benjamin; Yeakley, J. Alan; Geography and Environmental Systems; Geography and Environmental Systems
Rain gardens (RGs) are vegetated depressional areas that collect and infiltrate runoff, and are increasingly used to manage stormwater from detached houses in residential areas, although their catchment-scale effects are not well understood. I investigate the catchment-scale hydrologic effectiveness of residential RGs for reducing stormflow in suburban catchments, and how it varies across space and time. I developed a hydrologic model of a 3.1 km2 suburban catchment in Columbia, MD, USA, to simulate the effects of various residential RG implementation scenarios on event hydrology. I addressed the following research questions: (1) What is the capacity of residential RGs to mitigate event runoff in an intermediate-sized, suburban catchment? (2) What are the effects of spatial distribution of RGs on event runoff? and (3) What are the effects of rainfall characteristics and antecedent moisture condition (AMC) on the catchment-scale effectiveness of residential RGs for event runoff control?Using the Storm Water Management Model (SWMM), I simulated implementation of RGs at 25%, 50%, 75%, and 100% of detached houses in the study catchment to determine the effects on peak flow, runoff volume, and lag time over a 3-year period. I also simulated three contrasting pairs of spatial scenarios: upstream vs. downstream, clustered vs. dispersed, and near-stream vs. far-stream RG implementation scenarios. Finally, I analyzed the influence of rainfall characteristics and AMC on the effectiveness of RGs for event runoff control in the study catchment. I found that, on average, treating 100% of residential rooftops with RGs reduced peak flows by 14.5%, reduced runoff volumes by 11.7%, and increased lag times by 2.9% for the 211 rainfall events in the simulation period. The results of the spatial scenario simulations indicated that the spatial distribution of RGs had a small but statistically significant effect (p<0.01) on event runoff. On average, peak flows and runoff volumes in the clustered scenario were 2.4% less and 0.2% less, respectively, than those of the dispersed scenario. Peaks flows and runoff volumes in the upstream scenario were 2.5% less and 0.2% more, respectively, than those of the downstream scenario, on average. Peak flows and runoff volumes for the near-stream scenario were 1.1% more and 0.3% more, respectively, than those of the far-stream scenario, on average. Mean lag times for the spatial scenarios were all within 1.0% of those of their partner scenarios. Finally, I found that the cumulative effectiveness of RGs for reducing peak flows and increasing lag times decreased significantly with increasing rainfall depth, intensity, and duration. Runoff volume reduction was negatively correlated with rainfall depths above 10 mm and with rainfall intensities above 10 mm/hr, but not with storm duration. Catchment-scale RG performance was not correlated with two proxies for catchment AMC (i.e., 7-day antecedent rainfall and pre-event discharge). This research demonstrates that residential RGs can significantly improve the runoff response of suburban catchments, and that their effectiveness varies depending on their spatial distribution and on rainfall characteristics.
Digital equity in a crowded tool space: Navigating opportunities and challenges for equitable implementation of conservation technologies
(Wiley, 2024-12-24) Tabor, Karyn M.; Stavros, Natasha; Biehler, Dawn; Castillo-Villamor, Liliana C.; Mahmoudi, Dillon; Moreno Amado, Luis Mario; Holland, Margaret
We call on conservation funders, technology developers, and practitioners to explore how digital technologies can transform conservation practice. Actors supporting, developing, and funding digital technologies for conservation must address digital inequity and reduce the societal risks of digital technologies that may undermine conservation goals. We highlight the challenges in leveraging digital conservation technologies and recommend approaches to increase access to digital technologies for uptake by diverse users while supporting equitable participation from diverse user communities to shape digital technologies and their applications. Improving access to and use of tools may be achieved through strategic funding for digital design that recognizes and supports local solutions and diverse practices and perspectives. With increasing digital access, funders must also emphasize adherence to safeguards and protocols to reduce risks associated with digital technologies. By adopting more ethical methodologies related to digital technologies, we not only enhance global sustainability but also foster collaborative relationships with communities, recognizing the intrinsic value of their expertise in conservation initiatives and jointly safeguarding the environment to ensure the well-being of all. Encouraging more equitable approaches to conservation technologies underpins global priorities for sustainable development by centering and supporting the communities most directly involved in conservation action.
The Anthropocene Confirms Human Transformation of the Earth System
(2024-12-11) Kaplan, Jed O.; Ellis, Erle C.
Human influences in the Earth System are now as important as variations in Earth抯 orbit around the sun and plate tectonics in controlling climate and many other Earth System processes, at least on societally relevant timescales. Humans move sediment, affect plant and animal populations, and emit greenhouse gases with magnitudes and rates that are well above preanthropogenic backgrounds, even compared to periods of abrupt change visible in geologic time. Traces of human activity are detectable in all major planetary spheres, from the lithosphere to the atmosphere, in the deep oceans, and in every terrestrial ecosystem. While geologists chose not to define the anthropocene as a geologic epoch, it remains a critical concept in the Earth sciences for recognizing the increasingly powerful influence of human societies in shaping the Earth System. Viewing the anthropocene as a complex and heterogeneous event that began gradually with the emergence of modern humans and continues to accelerate to the present acknowledges the way human societies have altered this planet, first locally and eventually globally, both inadvertently and intentionally. This deeper history of human-environment interactions is apparent from current evidence.
Linking Biodiversity and Human Wellbeing in Systematic Conservation Assessments of Working Landscapes
(MDPI, 2023-06-21) Huber, Patrick R.; Baker, Matthew; Hollander, Allan D.; Lange, Matthew; Miller, Daphne; Quinn, James F.; Riggle, Courtney; Tomich, Thomas P.
Systematic land use planning to address environmental impacts does not typically include human health and wellbeing as explicit inputs. We tested the effects of including issues related to human health, ecosystem services, and community wellbeing on the outputs of a standard land use planning process which is primarily focused on environmental variables. We consulted regional stakeholders to identify the health issues that have environmental links in the Sacramento, California region and to identify potential indicators and datasets that can be used to assess and track these issues. Marxan planning software was used to identify efficient land use patterns to maximize both ecological conservation and human health outcomes. Outputs from five planning scenarios were compared and contrasted, resulting in a spatially explicit series of tradeoffs across the scenarios. Total area required to meet imputed goals ranged from 10.4% to 13.4% of the total region, showing somewhat less efficiency in meeting biodiversity goals when health outcomes are included. Additionally, we found 4.8% of residential areas had high greening needs, but this varied significantly across the six counties. The work provides an example of how integrative assessment can help inform management decisions or stakeholder negotiations potentially leading to better management of the production landscapes in food systems.
Accuracy differences in aboveground woody biomass estimation with terrestrial laser scanning for trees in urban and rural forests and different leaf conditions
(Springer, 2023-06-01) Arseniou, Georgios; MacFarlane, David W.; Calders, Kim; Baker, Matthew
Both rural and urban forests play an important role in terrestrial carbon cycling. Forest carbon stocks are typically estimated from models predicting the aboveground biomass (AGB) of trees. However, such models are often limited by insufficient data on tree mass, which generally requires felling and weighing parts of trees. In this study, thirty-one trees of both deciduous and evergreen species were destructively sampled in rural and urban forest conditions. Prior to felling, terrestrial laser scanning (TLS) data were used to estimate tree biomass based on volume estimates from quantitative structure models, combined with tree basic density estimates from disks sampled from stems and branches after scanning and felling trees, but also in combination with published basic density values. Reference woody AGB, main stem, and branch biomass were computed from destructive sampling. Trees were scanned in leaf-off conditions, except evergreen and some deciduous trees, to assess effects of a leaf-separation algorithm on TLS-based woody biomass estimates. We found strong agreement between TLS-based and reference woody AGB, main stem, and branch biomass values, using both measured and published basic densities to convert TLS-based volume to biomass, but use of published densities reduced accuracy. Correlations between TLS-based and reference branch biomass were stronger for urban trees, while correlations with stem mass were stronger for rural trees. TLS-based biomass estimates from leaf-off and leaf-removed point clouds strongly agreed with reference biomass data, showing the utility of the leaf-removal algorithm for enhancing AGB estimation.
A data pedigree system to support geospatial analyses of human-environment interactions in data poor contexts
(Taylor & Francis, 2024-12-18) Magliocca, Nicholas R.; Sink, Carter D.; Devine, Jennifer A.; Fagan, Matthew E.; Aguilar-González, Bernardo; McSweeney, Kendra; Mukherjee, Rohit; Nielsen, Erik A.; Sesnie, Steven E.; Tellman, Beth; Arellano-Thompson, Elise
Geospatial analyses of human-environment interactions are challenged by the multi-scale, multi-dimensional nature of human-environment systems. Research in such contexts must often rely on integrating multiple, independently produced data sources, which presents heterogenous data qualities and interoperability challenges. Understanding data quality and transparency becomes increasingly important in these contexts, and multi?granularity and context specific spatial data quality indicators are needed. We develop a data pedigree system that accounts for multiple data quality aspects, geospatial ambiguities that may hinder interoperability, and the fitness-for-use of each data source for indicating causal linkages between human activities and environmental change. We demonstrate its application to a particularly challenging and data sparse case study of identifying the location and timing of transnational cocaine trafficking, or ‘narco-trafficking’, in Central America with five spatial and temporal data quality indicators: geographic clarity, geographic interpretation, provenance, temporal specificity, and narco-trafficking certainty. The proposed data pedigree system provides a systematic and coherent analytical framework for interoperability, comparison, and corroboration of fragmented and incomplete data, which are needed to support advanced geospatial analyses, such as causal inference techniques. The study demonstrates the transferability and operationalization of the data pedigree system for examining complex human-environment interactions, especially those influenced by illicit economies.
Canopy composition drives variability in urban growing season length more than the heat island effect
(Elsevier, 2023-08-01) Alonzo, Michael; Baker, Matthew; Caplan, Joshua S.; Williams, Avery; Elmore, Andrew J.
The elevated heat of urban areas compared to their surroundings makes humid temperate cities a useful preview of future climate effects on natural forest phenology. The utility of this proxy rests on the expectation that trees in urban areas alter their phenology in response to warmer site conditions in spring and fall. However, it is possible that apparent lengthening of the growing season is instead governed by human-driven tree species selection and plant functional type (PFT; trees, shrubs, turfgrass) heterogeneity typical of managed landscapes. Without the use of highly spatially and temporally resolved remote sensing data, the roles of tree taxonomy and local site characteristics (e.g., impervious cover) in controlling phenology remain confounded. To understand the drivers of earlier start of season (SOS) and later end of season (EOS) among urban trees, we estimated individual tree phenology using >130 high-resolution satellite images per year (2018–2020) for ~10,000 species-labeled trees in Washington, DC. We found that species identity alone accounted for 4× more variability in the timing of SOS and EOS compared with a tree's planting location characteristics. Additionally, the urban mix of PFTs may be more responsible for apparent advances in SOS (by between 1.8 ± 1.3 and 3.5 ± 1.3 days) than heat per se. The results of this study caution against associating longer growing seasons in cities—observed in moderate to coarse resolution remote sensing imagery—to within-species phenological plasticity and demonstrate the power of high-resolution satellite data for tracking tree phenology in biodiverse environments.
Predicting Urban Trees’ Functional Trait Responses to Heat Using Reflectance Spectroscopy
(MDPI, 2024-1) Kyaw, Thu Ya; Alonzo, Michael; Baker, Matthew; Eisenman, Sasha W.; Caplan, Joshua S.
Plant traits are often measured in the field or laboratory to characterize stress responses. However, direct measurements are not always cost effective for broader sampling efforts, whereas indirect approaches such as reflectance spectroscopy could offer efficient and scalable alternatives. Here, we used field spectroscopy to assess whether (1) existing vegetation indices could predict leaf trait responses to heat stress, or if (2) partial least squares regression (PLSR) spectral models could quantify these trait responses. On several warm, sunny days, we measured leaf trait responses indicative of photosynthetic mechanisms, plant water status, and morphology, including electron transport rate (ETR), photochemical quenching (qP), leaf water potential (?leaf), and specific leaf area (SLA) in 51 urban trees from nine species. Concurrent measures of hyperspectral leaf reflectance from the same individuals were used to calculate vegetation indices for correlation with trait responses. We found that vegetation indices predicted only SLA robustly (R2 = 0.55), while PLSR predicted all leaf trait responses of interest with modest success (R2 = 0.36 to 0.58). Using spectral band subsets corresponding to commercially available drone-mounted hyperspectral cameras, as well as those selected for use in common multispectral satellite missions, we were able to estimate ETR, qP, and SLA with reasonable accuracy, highlighting the potential for large-scale prediction of these parameters. Overall, reflectance spectroscopy and PLSR can identify wavelengths and wavelength ranges that are important for remote sensing-based modeling of important functional trait responses of trees to heat stress over broad ranges.
THE ROLE OF DISASTER SUBCULTURES IN LOCAL BUSINESS COMMUNITY PREPAREDNESS: A CASE STUDY OF STAKEHOLDERS IN COASTAL MONMOUTH COUNTY, NEW JERSEY
(MSAAG, 2024) Howell, Nyla; Leichenko, R.; Clemens, M.; Cann, K.; Madajewicz, M.; Solecki, W.; Kaplan, M.; Herb, J.
Extreme weather events are increasingly affecting coastal communities, often leading to economic and social disruption within these areas. The businesses located within coastal communities are especially vulnerable to climate-related shocks, yet relatively little is known about how the experience of prior disaster events affects business preparedness and planning for future extreme events. This study applies the concept of a disaster subculture to investigate whether and how prior extreme events affect climate resilience practices among small and mediumsized businesses in coastal New Jersey. The methods for the study entailed qualitative analysis of interviews conducted with businesses and related stakeholders during the Spring of 2022. The results of the study indicate that elements of four possible disaster subcultures are present in the region and that these subcultures are influencing business mitigation and preparedness practices and community recovery. A future research direction could consider disaster subculture influence on an individual level and how subcultures may influence household preparedness.
Soil Methane and Carbon Dioxide Fluxes from Cropland and Riparian Buffers in Different Hydrogeomorphic Settings
(Wiley, 2015-07-01) Jacinthe, P. A.; Vidon, P.; Fisher, K.; Liu, X.; Baker, Matthew
Riparian buffers contribute to the mitigation of nutrient pollution in agricultural landscapes, but there is concern regarding their potential to be hot spots of greenhouse gas production. This study compared soil CO₂ and CH₄ fluxes in adjacent crop fields and riparian buffers (a flood-prone forest and a flood-protected grassland along an incised channel) and examined the impact of water table depth (WTD) and flood events on the variability of gas fluxes in riparian zones. Results showed significantly (P < 0.001) higher CO₂ emission in riparian areas than in adjoining croplands (6.8 ± 0.6 vs. 3.6 ± 0.5 Mg CO₂–C ha⁻¹ yr⁻¹; mean ± SE). Daily flux of CO₂ and soil temperature were significantly related (P < 0.002), with Q₁₀ values ranging between 1.75 and 2.53. Significant relationships (P < 0.05) were found between CH₄ daily flux and WTD. Flood events resulted in enhanced CH₄ emission (up to +44.5 mg CH₄–C m⁻² d⁻¹ in a swale) under warm soil conditions (>22°C), but the effect of flooding was less pronounced in early spring (emission <1.06 mg CH₄–C m⁻² d⁻¹), probably due to low soil temperature. Although CH₄ flux direction alternated at all sites, overall the croplands and the flood-affected riparian forest were CH₄ sources, with annual emission averaging +0.04 ± 0.17 and +0.92 ± 1.6 kg CH₄–C ha⁻¹, respectively. In the riparian forest, a topographic depression (<8% of the total area) accounted for 78% of the annual CH₄ emission, underscoring the significance of landscape heterogeneity on CH₄ dynamics in riparian buffers. The nonflooded riparian grassland, however, was a net CH₄ sink (−1.08 ± 0.22 kg CH₄–C ha⁻¹ yr⁻¹), probably due to the presence of subsurface tile drains and a dredged/incised channel at that study site. Although these hydrological alterations may have contributed to improvement in the CH₄ sink strength of the riparian grassland, this must be weighed against the water quality maintenance functions and other ecological services provided by riparian buffers.
First results and on-orbit performance of the Hyper-Angular Rainbow Polarimeter (HARP2) on the PACE satellite
(SPIE, 2024-11-20) Martins, J. Vanderlei; Fernandez-Borda, Roberto; Puthukkudy, Anin; Xu, Xiaoguang; Sienkiewicz, Noah; Smith, Rachel; McBride, Brent; Dubovik, Oleg; Remer, Lorraine
The Hyper-Angular Rainbow Polarimeter-2 (HARP2) was launched on board the Plankton, Aerosol, Cloud and ocean Ecosystem (PACE) mission, in February 2024, for the global measurement of aerosol and cloud properties as well as to provide atmospheric correction over the footprint of the Ocean Color Instrument (OCI). HARP2 is designed to collect data over a wide field of view in the cross-track direction (+/-47deg) allowing for global coverage in about two days, as well as an even wider field of view in the along-track direction (+/-54deg) providing measurements over a wide range of scattering angles. HARP2 samples 10 angles at 440, 550, and 870nm focusing on aerosol and surface retrievals, and up to 60 angles at 670nm for the hyper-angular retrieval of cloud microphysical properties. The HARP2 instrument collects three nearly identical images with linear polarizers aligned at 0°, 45°, and 90° that can be converted to push-broom images of the I, Q, and U Stokes parameters for each angle, and each wavelength. The HARP2 technology was first demonstrated with the HARP CubeSat satellite which collected a limited dataset for 2 years from 2020 to 2022. HARP2 extends these measurements to a full global coverage in two days, seven days a week.
Tree plantations and forest regrowth are linked to poverty reduction in Africa
(Nature, 2024-11-20) den Braber, Bowy; Hall, Charlotte M.; Rhemtulla, Jeanine M.; Fagan, Matthew E.; Rasmusssen, Laura Vang
Numerous countries have adopted large-scale tree planting programs as a climate mitigation strategy and to improve local livelihoods. However, it remains poorly documented how the surge in tree plantations has altered local livelihoods. Here, we assess whether tropical tree plantation expansion and forest regrowth across 18 African countries are associated with local people’s living standards. By combining a recent map that distinguishes tree plantations from regrowth from 2000 to 2012 with multidimensional poverty measures from more than 200,000 households, we find a positive association between people's living standards and areas where tree plantations have expanded or, to a lesser extent, forest regrowth has occurred. Because tree plantations make up a large proportion of recent increases in tropical tree cover – and controversy remains about their potential impacts on both biodiversity and local people – our study provides broad empirical support for the idea that tree plantations and forest regrowth can be linked with reduced poverty in the short term.

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