Biophysical Indicators Research Articles

A Time-Series Approach to Detect Urbanized Areas Using Biophysical Indicators and Landsat Satellite Imagery

Detecting spatiotemporal dynamics of urbanization is essential to study the patterns and processes of urban ecosystems. However, urban areas are difficult to classify, and migrating static classification algorithms to dynamic detection is also challenging. Here, we develop a time-series approach for the detection, in which urbanization processes are represented by the temporal trajectories of biophysical indicators. According to the spectral analysis of land-cover classes, the indicators of normalized difference vegetation index, automated water extraction index, biophysical composition index, and shortwave infrared index are selected to characterize urbanization. The temporal trajectories of these indicators are calculated using Landsat data on the google earth engine platform; and their long-term trends and abrupt changes are estimated by the Theil-Sen estimator and Mann–Kendall test, as well as the Pettitt test. The urbanized pixel classes are identified from the possible trend combinations of the indicators, in which the falsely alarmed pixels are excluded by the time-series analyses of the indicators. Three Chinese cities—Fuzhou, Nanchang, and Xining—in various physical environments are selected to demonstrate the proposed approach. The accuracy assessments using very high resolution images achieve the overall accuracies above 90% in the three areas, showing comparable performance to supervised techniques whereas no ancillary data are required. By the comparisons with two other urban products, the advantages of the proposed approach in detecting urbanization processes in the early stage and weak impervious situation are demonstrated. Due to little human intervention involved in the proposed approach, it could be readily adapted to other regions.

Identifying Indicators to Evaluate Community-Managed Freshwater Protected Areas in the Lower Mekong Basin: A Review of Marine and Freshwater Examples

Protected areas are frequently established as a management tool to conserve terrestrial and aquatic habitats and species. Monitoring and evaluation are a necessary part of adaptive management to determine whether such protected areas are effectively meeting their objectives. While numerous initiatives have developed methods to evaluate terrestrial and marine protected areas (MPAs), similar efforts and resources are lacking for freshwater protected areas (FPAs), which have become widespread as a community-based fisheries management approach in the Lower Mekong Basin (LMB). This review summarizes published literature on the evaluation of marine and freshwater protected areas to provide guidance on the evaluation of community-managed FPAs in the LMB. Specifically, the review examines several indicators related to common objectives of aquatic protected areas and provides considerations for measuring these indicators in the context of community-managed freshwater protected areas in the LMB. Key conclusions include that first, FPAs should be established with clearly defined objectives, and these objectives should inform the selection of indicators for evaluation. Second, indicators identified for MPAs are highly relevant to FPAs, although methods may require adaptation to a freshwater environment. Finally, socioeconomic and governance indicators are overlooked in both MPA and FPA evaluations compared to biophysical indicators, and interdisciplinary assessment teams could ensure these indicators receive adequate consideration.

Assessment of six soil ecosystem services by coupling simulation modelling and field measurement of soil properties

Soil is a reservoir of natural capital that provides several ecosystem services, ensuring human well-being and sustainable socioeconomic development. Many researchers nevertheless argue that there is no consensus on practical indicators to assess soil ecosystem services (SES). As many policy decisions rely on metrics and indicators to communicate concise and relevant information, an assessment of ecosystem service indicators can help identifying gaps hindering policymakers from more fully adopting ecosystem service approaches. The aim of this study was to develop a method to quantitatively evaluate six SES using a set of indicators derived from dynamic soil and crop modelling using the STICS model developed by INRA. In a 6775 km2 study area in north-western France (Brittany), 64 soil sampling points, located in agricultural areas, were selected following a stratified random sampling design based on soil parent material stratification. STICS inputs required climate data, soil property data and soil and landscape management practices. Over a baseline period from 1988 to 2018, similar crop management practices were simulated that reflected the dominant one performed by conventional farmers across the study site: applying organic and mineral fertilizers to a maize-wheat-catch crop rotation. Also, STICS outputs were used to derive six biophysical indicators characterizing six SES. Both mean and annual SES indicators were calculated and analyzed. Interrelations among SES indicators and soil properties were investigated using a Pearson correlation matrix, multivariate variance analysis and regression-based methods. The main results revealed that pedological and inter-annual variability were the main drivers of SES provision, particularly for ground water recharge, plant biomass provision, plant water provision and carbon sequestration. All SES were strongly correlated, except carbon sequestration and plant nitrogen provision, which showed weak correlations with the rest of SES. Moreover, analyzing interrelations between SES indicators and soil properties such as soil depth, soil texture and its related variables such as available water capacity played a predominant role in ensuring high levels of water-related SES indicators. Meanwhile, physicochemical soil properties were strongly correlated with carbon sequestration but less so with plant nitrogen provision. Overall, these findings characterize the effect of soil variability on SES provision using modelling and field measures of several soil properties, which can be useful for policy makers.

Soil moisture regime and canopy closure structure subalpine understory development during the first three decades following fire

Subalpine coniferous forests are adapted to cycles of fire and successional development, but increasing fire frequency and severity are altering historical stand structure, composition, and plant diversity. For instance, conifer regeneration has become increasingly variable as a result of prolonged aridity following fire, but the potential cascading effects on understory community development remain virtually unexplored. We used a natural experiment to investigate the relationships among understory plant succession, soil moisture regime, and variable tree canopy development over 30 years following the 1988 fires in the Greater Yellowstone Ecosystem, U.S.A. In 1990, at each of two study areas, plots were established in different site types defined by burn status (burned or unburned) and soil moisture regime (mesic or xeric), determined using biophysical indicators. We asked: (1) Are differences in soil moisture regime associated with differences in understory community composition (species richness, diversity, and functional group representation) during the first three decades after fire? (2) Does the relationship between soil moisture regime and community composition change over time as subcanopy (height >137 cm) tree densities increase? We confirmed our original designations of soil moisture regime using in situ measurements of soil moisture. Over the first decade of succession, species richness and diversity were lower in xeric-burned than in mesic-burned plots. Nearly 30 years after fire at the south-aspect study area, where subcanopy tree densities were low, seral understories diverged by soil moisture regime. There, graminoid cover was 23-fold higher, and forb cover was 3-fold lower, in xeric-burned than in mesic-burned plots. In contrast, in the mixed aspect study area, subcanopy tree densities were markedly higher. There, the understory did not vary by soil moisture regime, converging successionally and becoming more similar to unburned forest communities. Our results suggest that site-specific soil moisture regimes structure the early trajectory of post-fire understory recovery, but the relationship diminishes as tree canopies develop over time. However, under a warming climate, variable tree canopy development may compound increasing aridity, particularly on xeric sites, resulting in decreases in plant diversity and forb cover, increases in graminoid cover, and the potential for altered successional dynamics.

Abstract 15503: Biophysical Indicators of Acute Pulmonary Vein Isolation With a Novel Cryoballoon

Introduction: Low nadir temperature (N T ) and long thaw times with cryoballoon ablation are associated with successful PVI. Recently, a cryo-system was designed to improve catheter stability during ablation via a balloon (CB, POLARx™, Boston Scientific) that maintains uniform pressure and size. The purpose of this study was to evaluate whether the CB biophysical parameters, including time to -40 o C (TT40), N T , time to thaw (iTT0), and time to 15 o C (iTT15), are associated with acute PVI success in paroxysmal AF patients. Methods: Ablation was delivered for 180s if isolation was achieved in ≤ 60s or 240s if isolation occurred after 60s. PVI was confirmed via entrance and exit block. Biophysical parameters were evaluated for 3 groups: block with 180s ablation, block with 240s ablation, and for unsuccessful initial treatments (gap veins). The diagnostic accuracy for predicting PVI was assessed using area under (AUC) the receiver operator characteristic (ROC) curve for ablations > 120s. Results: Forty-six consecutive de novo PVI procedures at 4 centers were analyzed (n=234 ablations). All PVs were isolated using the CB alone, with the vast majority within 60s. During freeze, TT40 and N T were significantly shorter and colder for isolated veins compared to gap veins (Table). During thaw, iTT0 and iTT15 were significantly longer for isolated veins compared to gap veins (Table). ROC analysis found iTT15 had the highest diagnostic accuracy for isolation (AUC: 0.85) followed by N T (AUC: 0.81), iTT0 (AUC: 0.77), and TT40 (AUC: 0.72). Optimal cutoff values for iTT15 and N T were 33.5s and -48 o C, which had positive predictive values for acute block of 96.6% and 93.5%. Conclusions: When using the novel CB, ablations reaching < -48 o C and having thaw times to 15 o C > 33.5s were predictive of acute block in PVI, providing guidance toward improved workflow and potential reduction in procedural time.

A rapid approach for informing the prioritization of degraded agricultural lands for ecological recovery: A case study for Colombia

Turning national restoration commitments into action involves systematic spatial planning and prioritization of areas for investment. To achieve restoration at the landscape level, efforts must focus on ecological recovery, where productivity and ecosystem services are recovered on degraded agricultural lands, to meet not only environmental objectives but socioeconomic objectives as well, which can be accomplished through the establishment of sustainable land-use systems (SLUS). As financial resources for restoration are limited, identifying areas where resources can be used efficiently to achieve particular restoration objectives is critical. This study presents a rapid approach to identifying and prioritizing degraded agricultural lands for low-cost ecological recovery. Using publicly available remote sensing datasets at the national level, we apply the proposed methodology to Colombia, where we identify opportunities for cost-effective interventions on productive lands with moderate to light degradation, based on biophysical indicators of soil degradation. In tandem, we identify areas experiencing underutilization, where SLUS can be used to sustainably intensify production, and overutilization, where SLUS can be used to mitigate soil degradation. We identify and map over 10.3 million ha of land with potential for ecological recovery. We find that the Caribbean region proportionally has a high prevalence of moderately degraded agricultural and agroforestry soils, while the Andean region has a high proportion of moderately degraded production forestry soils. Our results aid in the identification and prioritization of areas where multifunctional SLUS, such as agroforestry, agroecology or climate-smart agriculture, can be developed to restore productivity and ecosystem services to degraded agricultural lands.

Relating social networks, ecological health, and reservoir basin governance

AbstractThe Columbia River Basin is a complex social‐ecological system, spanning political, legal, socio‐economic, geographic, and biophysical boundaries. Outreach to others in social networks develops fundamental communications needed for sustainable collaborations in adaptive management. However, operationalizing and comparing measures of social processes and outcome success in biophysical indicators remains challenging for resource managers. Using survey‐based research, we examined the interactions for water resource governance of five Columbia River reservoir basins in the northwestern US and Canada: Lakes Chelan, Roosevelt, Pend Oreille, Koocanusa, and člq'etkw (Flathead). Respondents included: water resource professionals working for Tribes/First Nations, federal, state, or provincial departments in water quality and/or fisheries, and people who engage in the networks on behalf of area businesses, government offices, public services, non‐profit organizations, and other entities. Perceived social process metrics in these governance networks included the levels of collaboration and inclusiveness, common goals, common strategies, identifying issues, implementing action, and the adequacy of available scientific data. We evaluated social measures relative to participant‐reported changes in physical lake health indicators. Qualitative data‐enhanced understanding of basin‐specific differences. Correlations of social by ecological measures varied widely between basins. Even moderate to strong functionality parameters did not scale well from individual to cross‐basin levels, as many correlations vanished with data aggregated. However, data analysis at the basin scale revealed important variability across the region in scope and governance functionality. Process indicators such as identifying issues and implementing action yielded stronger relationships for 10‐year horizons than for 2 years, reflecting the lag‐time in resource action.

Seasonality of biological and physical systems as indicators of climatic variation and change

Evidence-based responses to climate change by society require operational and sustained information including biophysical indicator systems that provide up-to-date measures of trends and patterns against historical baselines. Two key components linking anthropogenic climate change to impacts on socio-ecological systems are the periodic inter- and intra-annual variations in physical climate systems (seasonality) and in plant and animal life cycles (phenology). We describe a set of national indicators that reflect sub-seasonal to seasonal drivers and responses of terrestrial physical and biological systems to climate change and variability at the national scale. Proposed indicators and metrics include seasonality of surface climate conditions (e.g., frost and freeze dates and durations), seasonality of freeze/thaw in freshwater systems (e.g., timing of stream runoff and durations of lake/river ice), seasonality in ecosystem disturbances (e.g., wildfire season timing and duration), seasonality in vegetated land surfaces (e.g., green-up and brown-down of landscapes), and seasonality of organismal life-history stages (e.g., timings of bird migration). Recommended indicators have strong linkages to variable and changing climates, include abiotic and biotic responses and feedback mechanisms, and are sufficiently simple to facilitate communication to broad audiences and stakeholders interested in understanding and adapting to climate change.

Retrieval of Leaf Area Index Using Sentinel-2 Imagery in a Mixed Mediterranean Forest Area

Leaf area index (LAI) is a crucial biophysical indicator for assessing and monitoring the structure and functions of forest ecosystems. Improvements in remote sensing instrumental characteristics and the availability of more efficient statistical algorithms, elevate the potential for more accurate models of vegetation biophysical properties including LAI. The aim of this study was to assess the spectral information of Sentinel-2 MSI satellite imagery for the retrieval of LAI over a mixed forest ecosystem located in northwest Greece. Forty-eight field plots were visited for the collection of ground LAI measurements using an ACCUPAR LP-80: PAR & LAI Ceptometer. Spectral bands and spectral indices were used for LAI model development using the Gaussian processes regression (GPR) algorithm. A variable selection procedure was applied to improve the model’s prediction accuracy, and variable importance was investigated for identifying the most informative variables. The model resulting from spectral indices’ variables selection produced the most precise predictions of LAI with a coefficient of determination of 0.854. Shortwave infrared bands and the normalized canopy index (NCI) were identified as the most important features for LAI prediction.

Assessment of regulating ES potential of lowland riparian hardwood forests in Poland

Lowland riparian hardwood forests are valuable habitats protected by EU Habitat Directive (EU code: 91F0). Today, in most areas across Europe they are extremely rare due to deforestation, drainage and river engineering. The remaining small forest patches are important parts of riparian ecological corridors and biodiversity hotspots, and provide valuable ecosystem services (ES) to humans. However, unlike other forest types, due to their rarity and often low accessibility their ES potential has not been duly recognized and assessed to date. In this work we propose a set of biophysical indicators to assess the regulating potential of riparian hardwood forests. Indicator values were obtained through extensive field work and direct measurements carried out on selected test sites located along the middle Vistula River. The specific objectives of this work were: (i) to estimate the potential of riparian hardwood forests to provide 11 regulating services and to identify interactions among them; (ii) to examine the effects of forest and environmental attributes on individual ES; (iii) to determine ES drivers. Our results clearly show that riparian hardwood forests may be regarded as multiservice hotspots. Their regulating potential has proved to be substantial and in case of many services higher than the potential of other forest ecosystems. However, disruption of the natural water regime due to the absence of flooding and artificial drainage reduces their potential mainly for water-related regulating services (e.g. water treatment). On the other hand, more mesic habitats are beneficial for melliferous plant species and thus for wild pollinators. Most of the strong and significant interactions among the studied regulating services are synergistic. The high ES potential quantified by the biophysical ecosystem-condition-related indicators can be used effectively to promote the maintenance or restoration of this type of forests. The outcomes of our research suggest that protective actions should focus on ensuring adequate soil-moisture conditions which determine the specificity of these ecosystems.

Effect of Epichloë endophyte-tall fescue symbiosis on rhizosphere aggregate stability and quality indicators under oxygen–limited conditions

Endophytic fungus-tall fescue symbiosis can improve the rhizosphere physical quality, but contribution of oxygen-limited conditions on this change, particularly in semiarid and arid regions has not been established yet. Therefore, the objective of this study was to evaluate the effects of endophyte-tall fescue symbiosis on the rhizosphere quality indicators under different aeration conditions in a greenhouse pot experiment. The treatments were seven levels of air-filled porosity, AFP (0, 0.025, 0.050, 0.750, 0.100, 0.125 and 0.150 m3 m−3) in a sandy loam soil, and two genotypes (75C and 75B) of tall fescue (Festuca arundinacea = Schedonorus arundinaceus Schreb.) each with endophytic fungus Epichlöe coenophiala (E+) and without endophyte (E−). Soil biophysical properties were determined on the intact soil aggregates from rhizosphere zone: structural stability (by HEMC, high energy moisture characteristic), percent of water-stable aggregates, water repellency, basal soil respiration and soil organic matter. The results showed that by decreasing the AFP, and reducing redox potential to <300 mV, (i) all biophysical indices, and the activity and population of soil microorganisms (especially fungi) significantly decreased, (ii) the role of biological and chemical aggregators was reduced and soil structure degradation was intensified, and (iii) aggregate stability indices and water repellency were associated with the quality of soil organic matter, rather than its quantity. Soil structural stability under genotype 75B was higher and lower than genotype 75C for the oxygen-limited and non-limited conditions, respectively. Stability indices, water repellency and soil organic matter content were greater in the rhizosphere of E+ plants compared to E− ones. No significant differences were observed for the HEMC stability indices between 75B and 75C genotypes for E+ plants, whereas for the E− plants, they were significantly greater in genotype 75C. Endophytic fungi increased the rhizosphere aggregate stability through the water-repellent exudates, extension of root system and enhanced organic carbon storage especially under oxygen-limited conditions.

Identifying priority biophysical indicators for promoting food-energy-water nexus within planetary boundaries

Food, energy, and water are critical resources for human well-being and an essential part of Sustainable Development Goals (SDGs). The food-energy-water (FEW) nexus can create cascading effects that influence critical earth system processes. However, how to promote FEW nexus safeguarding within the planetary boundaries is still unclear. Based on global datasets of official SDG-statistics, an operating framework combined planetary boundaries and the FEW nexus was constructed. We found that although there are substantial differences in the FEW nexus performances among various countries, the overall development of three branches is coordinated. However, the massive resource consumption associated with promotion of the FEW nexus can severely transgress multiple planetary boundaries. Optimistically, if the highest efficiency is considered, the conflict between biophysical resource consumption and FEW nexus will be alleviated. Therefore, considering the utilization efficiency and independent contribution of biophysical resource, we suggest that CO2 emissions, ecological footprint, material footprint, nitrogen, and phosphorus should be considered priorities among biophysical indicators for promoting FEW nexus within planetary boundaries. This study could be a step toward coordinating the conflicts between promoting the FEW nexus and planetary boundaries and optimizing the implementation of SDGs agenda.

Mapping the effect of climate change on community livelihood vulnerability in the riparian region of Gangatic Plain, India

Indian Gangatic Plain is food basket of the country and vulnerable to variety of factors. The western region of the Gangatic plain is worst affected due to river bank erosion, frequent floods and climate change. The objective of the present study is to evaluate the livelihood vulnerability of the communities of riparian region of Manikchak block of the Gangatic plain by classifying the region into three zones based on the distance from the river. Livelihood Vulnerability Index (LVI) was applied by selecting suitable social and biophysical indicators through inductive and deductive approaches. The data for the estimation of LVI was collected by randomly selecting a total of 240 households from the villages of the three zones. The spatial modeling of LVI was achieved by applying spatial cluster and outlier analysis using local Moran’s I Index and by hotspot analysis using Getis-Org-G* statistics. Differential vulnerabilities across the three zones was observed with nearer to river zone was highly vulnerable. The villages nearer to river was more vulnerable due to greater exposure to river bank erosion and flood; higher sensitivity to insufficient access to basic amenities and poor adaptive capacity due to low socio-economic status and poor livelihood security. Moreover, the spatial pattern of hotspot was also identified as high vulnerable, high-low vulnerable and low vulnerable areas in the region. The results signified that the social and biophysical parameters were the main contributors for the differential vulnerabilities in the region. Therefore, the study concludes that the vulnerability of the communities varies with respect to their location to river and the differential approaches based on the social attributes of the communities and spatial characteristics of the location may be useful for addressing the livelihood vulnerability of the communities residing along the bank of the river.

Sentinel-2 Imagery Processing for Tree Logging Observations on the Białowieża Forest World Heritage Site

Deforestation is currently among the most critical ecological issues, which need to be addressed urgently. Hence, identification of effective environmental monitoring methods is of top priority, especially in locations where no precise ground-based data are available. Constant development of remote sensing technology provides an increasing number of tools needed for that purpose, based on extraction of information about Earth’s surface. One of the most advanced Earth Observation (EO) programs is Copernicus, established by European Space Agency (ESA). It incorporates a constellation of Sentinel satellites continuously delivering imagery, which can serve as input data for further environmental analyses. They can be performed in the Sentinel Application Platform (SNAP), the software also developed by ESA. The Sentinel-2 (S-2) mission was designed specifically for Earth’s surface observation. It acquires high-resolution data within visible and infrared range of electromagnetic spectrum (EMS), which has found applications in forest cover monitoring. In this paper, S-2 imagery was processed in SNAP software to determine its potential for deforestation observation on the example of 2017 tree logging in Białowieża Forest. For this purpose, images from October 2016 and 2018, covering the area of interest, were downloaded from the Copernicus Open Hub Platform. They then underwent pre-processing, involving atmospheric correction, resampling, and subset operations. As a part of environmental analysis, a set of chosen radiometric and biophysical indices was computed to preliminarily determine their usefulness for deforestation mapping. Index values were extracted from tree logging areas using pinpoints and region of interest (ROI) mask. The most effective indicators were the MERIS Terrestrial Chlorophyll Index (MTCI) and the Brightness Index (BI). The Normalized Difference Vegetation Index (NDVI), as well as the Ratio Vegetation Index (RVI), also displayed promising results. The results were visualized in Quantum GIS (QGIS) software, provided by the Open Source Geospatial Foundation (OSGeo).

Spatial Assessment of Ecosystem Services from Planted Forests in Central Vietnam

Globally, planted forests are increasing, providing increased resources to forest industries and ecosystem services (ES) to local and wider communities. However, assessment of the impacts of plantations on ES has been limited. Planted forests have expanded rapidly in Vietnam over the last 20 years, with much of the planting undertaken by smallholder growers using exotic Acacia and Eucalyptus species. This study aimed to test a framework to assess changes in four ES due to an increase in Acacia plantations from 2005–2015 in central Vietnam: carbon sequestration, sediment retention, water yield and habitat. Quantitative and qualitative indicators for each service were derived from the literature. Results showed that the area of planted forests in Quảng Trị and Thừa Thiên-Huế Provinces increased from 130,930 hectares (ha) to 182,508 ha, mostly replacing non-forest areas (degraded lands, grasslands and agricultural lands) and poor forests. The framework demonstrated capacity to assess the effect of planted forests on wood flow, carbon stocks, sediment retention, streamflow and the extent of wildlife habitat. Apart from the wood supply and carbon sequestration, more research is required to translate biophysical indicators to benefit relevant indicators related to human welfare. The study also revealed that the area of rich forests decreased by 20% over the ten years, mostly through degradation to poorer quality natural forests. Therefore, at the landscape scale, improvement in ES due to conversion of non-forests to planted forests was offset by a reduction in some services as a result of degradation of native forest from rich to poorer condition. Assessment of changes in ES due to planted forests also needs to consider other landscape changes. These analyses can inform policymakers, forest owners and managers, environmental organizations and local communities of the benefits and impacts of planted forests and provide an improved basis for payments for ES and potential additional income for smallholder tree growers.

Las huellas de la contradicción entre desarrollo y ambiente. Un análisis del metabolismo socioeconómico en América del Sur a través de sus huellas ecológica e hídrica

Throughout the last half of the twentieth century and at the beginning of the twenty-first century, the relationship between development and environment has been reconfigured in various ways. At the general level there are currently two antagonistic currents in conflict: the one that promotes sustainable development, and the one that, from the oxymoron development and environment, seeks alternatives to development. This work seeks to apply biophysical indicators to understand the biophysical structure of South America and provide methodologies for new alternatives to development. For this, the biophysical indicators of ecological footprint and water footprint are developed, built within the framework of analysis of material flows of the field of Ecological Economics, which will allow to determine the magnitude and characteristics of the flows of materials and energy that are derived of the productive profile and the pattern of external insertion of South America.

Predicting hot spots of aquatic plant biomass in a large floodplain river catchment in the Australian wet-dry tropics

Conservation planning processes and wetland management require spatial estimations of aquatic habitats to support the maintenance of aquatic biodiversity. However, physical access to several wetlands and freshwater habitats can be restricted due to difficult topography and technological limitations associated with ground-based observations. In addition to these constraints, the distribution of some aquatic primary producers in freshwater habitats and floodplains that are difficult to reach further complicates large-scale assessment of aquatic habitats using traditional field-based techniques. The main objective of this study is to predict the spatial distribution of hot spots of primary producers (aquatic plant biomass) and assess large-scale inundation patterns in a large floodplain wetland (Flinders catchment) in the wet-dry tropics of Australia. To this end, remote sensing biophysical indicators (vegetation and inundation) were integrated with flood water depth in a classification tree model. Results indicate that in terms of floodplain total inundation, the Flinders wetland hydrology is rather restricted immediately after the summer wet season, the period when most primary production happens. While this can be attributed to the fact that much of the observed annual variability (93%) in rainfall and surface runoff (95%) occur during the wet season, post flood recession patterns are indicators that underpin the somewhat limited alimentation of the Flinders floodplain during this period. As observed in this study, post flood inundation extents in the summers of 2009 and 2019 declined by approximately 89% and 87% within fourteen and ten days, respectively. Despite having a significantly higher magnitude than the 2009 summer flood event, the 2019 extreme ‘big wet’ period did not translate to higher floodplain productivity (aquatic plant biomass and surface water distribution) immediately after summer as was the case in 2009. Furthermore, the predicted extents of aquatic plant biomass and total floodplain inundation in the downstream Flinders show substantial temporal variation and suggest the floodplain wetland hydrology is largely driven by inter-annual changes in annual rainfall. The extents of these hot spots of biomass accumulation were found to be considerably associated with total floodplain inundation extent (r=0.94), rainfall (r=0.81), and discharge (r=0.68). Furthermore, advance statistical analyses show that downstream discharge and rainfall over the Flinders are significantly correlated (r=0.72). In addition to this, observed amplitudes of discharge and rainfall in extreme wet and dry years coincided with floodplain inundation patterns and distribution of hot spots of primary producers. While these relationships emphasize the importance of flow in the nourishment of the downstream catchment, they further corroborate the composite influence of local rainfall and discharge on total floodplain inundation and hot spots of primary producers.

Bioindicational Potential of Biophysical and Hydrobiological Indicators of Phytoplankton in Experiments with Laboratory Algocenoses

Bioindication, a method for the assessment of the quality of the natural environment with allowance for the state of the biota, is widely used to assess the impact of various factors on an ecosystem. Two problems remain relevant: on the one hand, the adequate selection of biological indicators of the ecosystem state with the greatest bioindicative potential, and, on the other, the establishment of the numerical boundaries of the norm for the indicators. A laboratory algocenosis has been created to study the bioindicational potential of hydrobiological and biophysical indicators. It consists of representatives of various classes of microalgae and cyanobacteria: Anabaena variabilis, Pleurochloris magna, Ankistrodesmus falcatus, and Stichococcus bacillaris. Salts of copper and zinc and diuron were used as effective toxicants. The method of local ecological norms was used for the analysis of the experimental data. The method is based on a computer analysis of the interrelated distribution of biological and physicochemical characteristics, i.e., on the search for boundaries of the factor and indicator norms for which suitable values of the indicator correspond to acceptable values of the factor and unacceptable values of the factor correspond to unsuitable indicator values. The paper analyzes data on 27 bioindicators: various fluorescence indicators, spectral characteristics; number and average volumes of cells of each type; parameters of the rank distribution of the number of species in the sample; evenness indices; nonparametric indices of species diversity; and the phytoplankton saprobity index. The boundaries of each indicator norm have been calculated; the most significant factors, as well as the boundaries of those factors' norm, have been revealed and determined. The bioindicators were compared by the average strength of connection with factors, the number of found significant factors, and their geometric mean value.

Sentinel-2 Leaf Area Index Estimation for Pine Plantations in the Southeastern United States

Leaf area index (LAI) is an important biophysical indicator of forest health that is linearly related to productivity, serving as a key criterion for potential nutrient management. A single equation was produced to model surface reflectance values captured from the Sentinel-2 Multispectral Instrument (MSI) with a robust dataset of field observations of loblolly pine (Pinus taeda L.) LAI collected with a LAI-2200C plant canopy analyzer. Support vector machine (SVM)-supervised classification was used to improve the model fit by removing plots saturated with aberrant radiometric signatures that would not be captured in the association between Sentinel-2 and LAI-2200C. The resulting equation, LAI = 0.310SR − 0.098 (where SR = the simple ratio between near-infrared (NIR) and red bands), displayed good performance ( R 2 = 0.81, RMSE = 0.36) at estimating the LAI for loblolly pine within the analyzed region at a 10 m spatial resolution. Our model incorporated a high number of validation plots (n = 292) spanning from southern Virginia to northern Florida across a range of soil textures (sandy to clayey), drainage classes (well drained to very poorly drained), and site characteristics common to pine forest plantations in the southeastern United States. The training dataset included plot-level treatment metrics—silviculture intensity, genetics, and density—on which sensitivity analysis was performed to inform model fit behavior. Plot density, particularly when there were ≤618 trees per hectare, was shown to impact model performance, causing LAI estimates to be overpredicted (to a maximum of X i + 0.16). Silviculture intensity (competition control and fertilization rates) and genetics did not markedly impact the relationship between SR and LAI. Results indicate that Sentinel-2’s improved spatial resolution and temporal revisit interval provide new opportunities for managers to detect within-stand variance and improve accuracy for LAI estimation over current industry standard models.

Cryoablation for atrial fibrillation.

Cryoballoon ablation for the treatment of atrial fibrillation has established itself as an effective and efficient modality for achieving pulmonary vein isolation. Over the past 13 years more than 100,000 Cryoballoon ablation procedures have been performed with the first to fourth generation cryoballoons. Over that time there have been significant advances in our understanding regarding the optimal procedural techniques. The purpose of this "topic in review" is to focus on the practical aspects of performing a Cryoballoon ablation procedure, within the context of the contemporary literature. Specifically there is a focus on how contemporary studies can inform clinical decision making and ensure operators are able to perform a safe and effective procedure.