Seasonal Disturbances Research Articles

Earth's earliest forest: fossilized trees and vegetation-induced sedimentary structures from the Middle Devonian (Eifelian) Hangman Sandstone Formation, Somerset and Devon, SW England

The evolution of trees and forests through the Devonian Period fundamentally changed the Earth's land biosphere, as well as impacting physical environments and geomorphology by stabilizing sediments and interacting with flowing air and water. From the mid-Givetian Age onwards, lignophyte flora are known to have been key parts of the machinery in the so-called Devonian landscape factory, but the impact of earlier forests, dominated by less woody cladoxylopsids, are not as well understood. We report here evidence for a previously unrecognized cladoxylopsid forest landscape, archived within the Eifelian Hangman Sandstone Formation of Somerset and Devon, SW England. This unit has previously been considered palaeobotanically depauperate, but is here shown to contain the earliest fossil evidence for such trees in the British record, as well as the oldest known evidence globally for the relative position of standing trees: in common parlance, a fossil forest. In addition to abundant fossil material attributable to the cladoxylopsid tree Calamophyton , and other early Mid-Devonian flora, the sedimentary context of the plant remains sheds light on the biogeomorphic impacts of these earliest forests. The trees colonized a sizeable distributive fluvial system that was prone to seasonal disturbance events. The nature of the sedimentary system has created a bias to those facies where biogeomorphic signatures are most frequently recorded (from the distal parts of the system), but across the whole system there is evidence of plant–sediment interactions in the form of vegetation-induced sedimentary structures, rooting features and accumulations of plant debris. Plant remains are also found in nearshore facies adjacent to the distributive fluvial system, attesting to the development of a novel non-marine/marine teleconnection from the production and export of new biological sedimentary particles. The Hangman Sandstone Formation is illustrative of the revolutionary power of cladoxylopsid trees as biogeomorphic agents, forming densely spaced forests and shedding exceptionally abundant plant debris, while also impacting local landforms and sediment accumulations and profoundly changing landform resilience against flood disturbance events. These findings provide evidence that the Eifelian Stage (393.3–387.7 Ma) marks the onset of tree-driven changes to physical environments that would forever change Earth's non-marine landscapes and biosphere. Supplementary material: Details of sedimentary facies and additional images of plant fossils are available at https://doi.org/10.6084/m9.figshare.c.7084873

Исследование аэрогазодинамических процессов переноса радона из горных массивов

Introduction. Drying tailings are a source of gaseous chemicals, in particular radon222, which is carried by air currents along the slopes of the gorge. These processes need constant monitoring. Purpose of research. Establishment of climatic conditions most influencing the measurements of mountain radon and its dispersion in the atmosphere. Research methods and materials. The data of weather stations located in the Alagir mountain gorge and the data of the mathematical model of this gorge were used to establish the characteristic wind roses at the points of the gorge selected for field measurements of mountain radon. Research results. It has been established that at the nearby points of the mountain gorge, the prevailing direction and strength of the wind can differ significantly. The differences depend on the landscape features of the surface of the slopes of the mountain gorge. This factor determines the direction of migration of chemical elements and decay products of mountain radon. This conclusion is confirmed by direct measurement of wind speed at two points in the gorge, as well as by the results of mathematical modeling. Discussion of research results. A preliminary calculation of the passive impurity concentration field within the mountain gorge shows the most characteristic places on the slopes of the gorge from the point of view of measurements. Preliminary algorithm for choosing the location of measurements. Determination of 210Pb content in natural «traps» or sediments can determine the migration paths of «mountain» radon and estimate the magnitude of its interaction with the nature of the gorge, subject to the following assumptions: 1) certain sampling sites are not subject to significant seasonal disturbances; 2) natural and climatic conditions, especially the amount of precipitation, in the studied gorge should not have abnormal changes before sampling; 3) sampling should preferably be carried out in autumn on fallen leaves in hollows, where post-sedimentary migration is limited. Approbation of the proposed measurement technique is discussed. Conclusion. The prevailing winds in the side arms of mountain gorges can differ significantly from the wind rose observed in the main part of the gorge and are determined mainly by landscape features near the observation point. This must be taken into account when measuring and analyzing the direction of migration of chemicals in mountain gorges. Mathematical modeling of aerodynamic processes in mountainous regions is a proven method for studying physical processes in mountain gorges, as well as the processes of dispersion of volatile geochemical elements emitted by sources in mountain gorges. It is shown that at the nearby points of the mountain gorge, the wind roses can differ significantly, which is confirmed by both measurements and mathematical modeling. This dictates the need for observations and taking into account the local wind rose at each measurement point. The results of radon measurements are presented, confirming the effectiveness of the proposed technique. Resume. 1. The article presents the results of mathematical modeling of aerodynamic processes in mountain gorges and the spread of gaseous impurities in the air. 2. It has been established that wind roses at nearby points on the slopes of a mountain gorge can differ significantly, both in the results of the mathematical model and in the results of measurements from weather stations. It is shown that the agreement between the modeling and measurement results is satisfactory. 3. The research results can be useful in planning measurements of radon concentrations as a predictive map of the distribution of mountain radon concentrations.

Seasonal Effect of the Vegetation Clumping Index on Gross Primary Productivity Estimated by a Two-Leaf Light Use Efficiency Model

Recently, light use efficiency (LUE) models driven by remote sensing data have been widely employed to estimate the gross primary productivity (GPP) of different terrestrial ecosystems at global or regional scales. Furthermore, the two-leaf light use efficiency (TL-LUE) model has been reported to improve the accuracy of GPP estimation, relative to the big-leaf MOD17 model, by separating the entire canopy into sunlit and shaded leaves through the use of constant clumping index estimation (Ω). However, ignoring obvious seasonal changes in the vegetation clumping index (CI) most likely results in GPP estimation errors since the CI tends to present seasonal changes, especially with respect to the obvious presence or absence of leaves within the canopy of deciduous vegetation. Here, we propose a TL-CLUE model that considers the seasonal difference in the CI based on the TL-LUE model to characterize general changes in canopy seasonality. This method composites monthly CI values into two or three Ω values to capture the general seasonal changes in CI while attempting to reduce the potential uncertainty caused during CI inversion. In theory, CI seasonality plays an essential role in the distribution of photosynthetically active radiation absorbed by the canopy (APAR). Specifically, the seasonal difference in CI values mainly considers the state of leaf growth, which is determined by the MODIS land surface phenology (LSP) product (MCD12Q2). Therefore, the one-year cycle (OYC) of leaf life is divided into two (leaf-off and leaf-on) or three seasons (leaf-off, leaf-scattering, and leaf-gathering) according to this MODIS LSP product, and the mean CI of each corresponding season for each vegetation class is computed to smoothen the uncertainties within each seasonal section. With these two or three seasonal Ω values as inputs, the TL-CLUE model by which the seasonal differences in CI are incorporated into the TL-LUE model is run and evaluated based on observations from 84 eddy covariance (EC) tower sites across North America. The results of the analysis reveal that the TL-LUE model widely overestimates GPP for most vegetation types during the leaf-on season, particularly during the growth peak. Although the TL-LUE model shows that the temporal characteristics of GPP agree with the EC observations in terms of general trends, the TL-CLUE model further improves the accuracy of GPP estimation by considering the seasonal changes in the CI. The result of GPP estimation from the TL-CLUE model shows a lower error (RMSE = 2.46 g C m−2 d−1) than the TL-LUE model (RMSE = 2.75 g C m−2 d−1) and somewhat decreases the eight-day GPP overestimation in the TL-LUE model with a constant Ω by approximately 9.76 and 8.970% when adapting three and two Ωs from different seasons, respectively. The study demonstrates that the uncertainty of seasonal disturbance in the CI, quantified by a standard deviation of approximately 0.071 relative to the mean CI of 0.746, is diminished through simple averaging. The seasonal difference in CI should be considered in GPP estimation of terrestrial ecosystems, particularly for vegetation with obvious canopy changes, where leaves go through the complete physiological processes of germination, stretching, maturity, and falling within a year. This study demonstrates the potential of the MODIS CI application in developing ecosystem and hydrological models.

First record of intraspecific cleaning behavior by the threatened Leuciscidae Squalius alburnoides (Steindachner, 1866) at the Guadiana River basin (Portugal).

Squalius alburnoides (Steindachner, 1866) is an endemic threatened species from the Iberian Peninsula. Here, we report the first observations of intraspecific cleaning behavior in isolated summer pools in the Guadiana River Basin (Portugal). We found that focal S. alburnoides solicited cleaning by adopting an immobile tail-stand position known as "posing," which immediately signaled a response to a few conspecifics that approached and inspect them. Our study expands the list of cleanerfish species in freshwaters, giving emphasis to the importance of mutual positive behavior within an endangered species, particularly when facing seasonal disturbance.

An apex predator engineers wetland food-web heterogeneity through nutrient enrichment and habitat modification.

The potential for animals to modify spatial patterns of nutrient limitation for autotrophs and habitat availability for other members of their communities is increasingly recognized. However, net trophic effects of consumers acting as ecosystem engineers remain poorly known. The American Alligator Alligator mississippiensis is an abundant predator capable of dramatic modifications of physical habitat through the creation and maintenance of pond-like basins, but its role in influencing community structure and nutrient dynamics is less appreciated. We investigated if alligators engineer differences in nutrient availability and changes to community structure by their creation of 'alligator ponds' compared to the surrounding phosphorus (P)-limited oligotrophic marsh. We used a halo sampling design of three distinct habitats extending outward from 10 active alligator ponds across a hydrological gradient in the Everglades, USA. We performed nutrient analysis on basal food-web resources and quantitative community analyses, and stoichiometric analyses on plants and animals. Our findings demonstrate that alligators act as ecosystem engineers and enhance food-web heterogeneity by increasing nutrient availability, manipulating physical structure and altering algal, plant and animal communities. Flocculent detritus, an unconsolidated layer of particulate organic matter and soil, showed strong patterns of P enrichment in ponds. Higher P availability in alligator ponds also resulted in bottom-up trophic transfer of nutrients as evidenced by higher growth rates (lower N:P) for plants and aquatic consumers. Edge habitats surrounding alligator ponds contained the most diverse communities of invertebrates and plants, but low total abundance of fishes, likely driven by high densities of emergent macrophytes. Pond communities exhibited higher abundance of fish compared to edge habitat and were dominated by compositions of small invertebrates that track high nutrient availability in the water column. Marshes contained high numbers of animals that are closely tied to periphyton mats, which were absent from other habitats. Alligator-engineered habitats are ecologically important by providing nutrient-enriched 'hotspots' in an oligotrophic system, habitat heterogeneity to marshes, and refuges for other fauna during seasonal disturbances. This work adds to growing evidence that efforts to model community dynamics should routinely consider animal-mediated bottom-up processes like ecosystem engineering.

Risk Assessment and Impact of Floods on the Transmission of Vector Borne Diseases

Floods are the result of natural disasters in an area due to prolonged continued and heavy rains and are frequently followed by a proliferation of mosquitoes due to the creation of a large number of breeding habitats. In the endemic zones for VBDs, vector mosquito species require special attention for planning immediate control measures as these areas may pose a threat to public health. Natural disasters continue to strike unabated, flash floods due to heavy rains, riverine floods,coastal floods and cloud burst floods. In general, floods are witnessed due to the concentrated spells of heavy rains during the monsoon months and seasonal disturbances. The low lying areas are submerged under water and remain water logged for a long duration. Slowly, the low lying water bodies thus created after receding of flood water, act as a breeding potential source for the vector mosquitoes. Some of the areas receive water from flushing of water from high altitude areas due to heavy rains or melting of ice. There is definite need for public health preparedness and response for the flood affected areas to reduce the transmission of VBDs with proper risk assessment. There are chances for the onset of transmission of VBDs to the population shifted to temporary shelter homes away from homes. Given the situation with the presence of congenial conditions owing to presence of favourable climatic variables for propagation of vectors, pathogens and susceptible population, there are chances of disease outbreaks. Therefore, the risk assessment of the flood affected area with the vulnerable population is essential to make preparedness and response to any onset of VBDs transmission. Disease and vector surveillance are the key elements to be in place for such flood affected areas during and after the floods.

A model predictive control approach to a water pumping system in an Australian cotton farm microgrid

This paper proposes a model predictive control (MPC) approach to operate a cotton farm microgrid for the efficient utilization of renewable energy and minimal operational cost of irrigation pumps. MPC is used because of its ability to handle disturbance and real-time parameter changes. This paper establishes the MPC model of grid-connected and off-grid microgrids. The effectiveness and robustness of the MPC model are analyzed through a case study. The simulation results show that the operating cost of the MPC solution for the grid-connected microgrid is AU$12,024 lower than the strategy in the baseline; it saves 11,142 kWh of energy from the grid. Furthermore, the MPC solution exhibits excellent robustness in controlling the reservoir’s water level. After adding the rainy season disturbance data, the system saves AU$16,019.5 of total operating costs compared to the baseline. When the rainy season and high evaporation disturbance are added together, the system still saves AU$13,302 of total operating costs compared to the baseline. For islanded microgrids, existing-scale renewable energy systems using MPC can increase the utilization rate of renewable energy sources by 7% compared to the baseline, equivalent to reducing 8467 L of diesel consumption. Moreover, if the scale of the renewable energy system is quadrupled, the renewable energy source utilization rate of the MPC solution will increase to 64%, which saves 12,399 L of diesel.

Dynamic Responses of a Pile with a Cap under the Freezing and Thawing Processes of a Saturated Porous Media Considering Slippage between Pile and Soil

The freezing/thawing stratification effect of seasonal factors or artificial disturbances in frozen soil regions has an important influence on the vertical vibration of the pile–soil–cap system. Taking into account the slippage between the pile and soil, a simplified layered analytical model of the vertical vibration of the pile–soil–cap system in a double-layered stratum under the freezing and thawing processes of a saturated porous medium was established, and the analytical solution of the dynamic response on the top of the pile cap was obtained. In this model, frozen saturated porous media and Biot’s porous media theory were used to simulate frozen soil and unfrozen soil, respectively. The validation of the slippage model was first verified by comparison with the results of the existing model tests. This was followed by a dynamic model test of the pile–soil–cap system in a self-made, ground-freezing system. In comparison with the analytical results and the experimental results of model tests under the freezing/thawing processes, the validation of the present model is further verified. A comprehensive parametric study reveals that the parameters of the frozen or thawed soil layer have significant effects on the amplitude–frequency curve of the vertical vibration of the pile foundation.

Graph-based block-level urban change detection using Sentinel-2 time series

Remote sensing technology has been frequently used to obtain information on changes in urban land cover because of its vast spatial coverage and timeliness of observation. Block-level change detection with high temporal resolution image data provides fine detail of urban changes, is suitable for urban management, and has gradually received widespread attention. High-dimensional features are required to express the heterogeneous structure of the blocks. High-dimensional high-frequency time series, namely, multivariate time series, are formed by arranging high-dimensional features chronologically. Classic change detection methods treat multivariate time series as univariate time series one by one. Few studies have analyzed the change in a multivariate time series by considering all variables as an entirety. Therefore, a graph-based segmentation for multivariate time series algorithm (MTS-GS) is proposed in this paper. Specifically, 1) we construct a similarity matrix to explore the changing patterns of multivariate time series for seasonal change, trend change, abrupt change, and noise disturbance; 2) a multivariate time series graph is defined based on the changing patterns; and 3) the corresponding graph segmentation algorithm is proposed in the paper to detect the abrupt and trend changes under noise and seasonal disturbances. Sentinel-2 images of the rapidly developing third-tier city of Luoyang, Henan province, China, are adopted to validate the algorithm. The F1-score in the spatial domain is 84.1%; the producer's and the user's accuracy in the temporal dimension are 81.8% and 80.1%, respectively. Seven change types are defined and extracted, showing the development pattern and the efficiency of land use in the city. Furthermore, the proposed MTS-GS can be used for pixel-level change detection and performs well under various time intervals and cloud covers.

Abiotic drivers shape seed inputs and outputs in a tropical wetland on Croton trinitatis population

BackgroundPredicting how natural and anthropogenic drivers shape different ecological indicators, such as plant populations along environmental gradients, can be a relevant tool for establishing management and conservation criteria of tropical wetlands. We aimed to assess the effects of seasonal flood disturbance, type of grasslands and topographical conditions on Croton trinitatis population distribution in a tropical wetland.MethodsThe study was carried out in a seasonally flooded grassland (Central-West Brazil). We conducted samplings of soil on the dry and flood hydrophases of the Pantanal. We took the samples in eight seasonal ponds, with 1 km interval between them. Transects were marked during the flood period, observing the water level, one in the lowest zone, in the middle of the pond = low (ca. 60 cm deep), one at the pond edge = mid (ca. 30 cm deep) and one in the higher zone, on the external part = high (ca. 1 cm deep).ResultsThe results showed that the topography, seasonality, and types of grassland determine differences in the abundance patterns of adult plants and seedlings, and seed bank and seed predation. The abiotic factors can shape plant population-related ecological processes and patterns, with outputs (germination and predation) and inputs (local dispersion and from neighbouring areas) of proportional seeds for the population maintenance in this environment.ConclusionWe emphasize the importance of these findings, to show that abiotic factors are not the only ones to be considered in ecological studies of distribution and structuring of populations in habitats with extreme seasonal events.

Non-Inversion Tillage as a Chance to Increase the Biodiversity of Ground-Dwelling Spiders in Agroecosystems: Preliminary Results

Spiders (Araneae) create abundant and diverse assemblages in many agroecosystems, where they play a crucial role as the main group of predators and pest controllers. However, seasonal disturbance in the agricultural environment (e.g., harvesting or ploughing) affects spider assemblages. The main aim of this research was to compare assemblages of Araneae colonising cereal fields cultivated under two different systems of soil tillage: conventional with ploughing and non-inversion tillage. The research covered plantations of triticale, wheat, and barley, situated in northeastern Poland. Ground-dwelling spiders were captured into modified pitfall traps filled up to 1/3 height with an ethylene glycol solution. In total, 6744 spiders representing 67 species classified in 13 families were caught. The traps were emptied every two weeks from the end of April until the end of July. A total of 2410 specimens representing 55 species were captured in the fields with simplified cultivation, while the remaining 4334 specimens representing 49 species were trapped in conventional fields where ploughing was performed. The Shannon diversity (H’) and evenness (J’) indices reached higher values in the fields without ploughing. According to IndVal Erigone, dentipalpis and Bathyphantes gracilis were signifi-cantly characteristic (p < 0.05) for non-inversion soil tillage, whereas six species, Oedothorax apicatus, Pardosa prativaga, Pardosa paludicola, Pachygnatha clerki, Dicimbium nigrum brevisetosum, and Clubiona reclusa, were typical of soil tillage with ploughing. The research showed that simplification of soil tillage in cereal fields improves the biodiversity of arachnofauna in agricultural ecosystems. The use of conventional tillage systems with ploughing promotes agrobiontic species of the families Linyphiidae and Lycosidae.

Differential responses in spider oviposition on crop-edge gradients in agroecosystems with different management

Semi-natural habitats in agricultural landscapes offer reproduction and feeding sites for natural predators of pests. Spiders are among the most abundant and diverse generalist predators and can efficiently suppress pest populations in agroecosystems. However, despite the importance of these habitats, there is a significant gap of knowledge on oviposition sites of spiders in agroecosystems. Our main goal was to investigate if semi-natural habitats play an important role in spider oviposition in two crops with different agricultural managements. Our specific objectives were to estimate where spider oviposition is highest (in semi-natural habitats or in crops); if there are different responses between crops (alfalfa and soybeans); and to measure trap-nests efficiency as shelter and breeding places for vegetation-dwelling spiders. We used trap-nest technique, a novel method to collect spiders and their eggsacs. We carried out the study in 15 sites in soybean and 10 sites in alfalfa crops in order to sample spiders’ eggsacs and shelters. Each sampled site consisted of a semi-natural habitat (enclosures or edges) and its adjacent crop. We found that the number of eggsacs decreased from semi-natural habitats towards the interior of the soybean crop and the opposite pattern in alfalfa, where the number of eggsacs significantly increased within the crop. Our results provide evidence that spider reproduction takes place outside the crops, albeit only in soybean crops. Our findings were different in alfalfa with minimum use of agrochemicals and with a lesser seasonal disturbance, with a higher spider oviposition compared to semi-natural habitats. In addition, our results have several important implications for the management of agroecosystems. We consider that the use of these trap-nests is a suitable and a reliable tool to study vegetation-dwelling spiders in different ecosystems.

MODIS NDVI Multi-Temporal Analysis Confirms Farmer Perceptions on Seasonality Variations Affecting Apple Orchards in Kinnaur, Himachal Pradesh

Apple cultivation in the Kinnaur district of the northern Indian State of Himachal Pradesh faces challenges from climatic changes and developmental activities. Farmers in the neighboring districts have already faced a major loss of livelihood due to seasonal changes. Therefore, it is important to study the extent of seasonal variations in the apple growing locations of this region. This study makes that attempt by assessing seasonality variations during a 15-year period from 2004 to 2018 when maximum construction activities occurred in this region. The study uses geospatial and statistical techniques in addition to farmer perceptions obtained during a field visit in November 2019. A temporal pattern using a normalized difference vegetation index (NDVI) based on Moderate Resolution Imaging Spectroradiometer (MODIS) was studied for seven apple-growing locations in the district. The results show high seasonal variations and reduced snowfall at lower elevations, resulting in less chilling hours, which are necessary for the healthy growth of apples. The normalized difference snow index (NDSI) and rainfall show a high correlation with apple growth. Local farmers are unprepared for future seasonal disturbances, as they lack early warning systems, insurance for apple crops, and alternative livelihood options.

Prokaryotic community diversity in the sediments of saline lagoons and its resistance to seasonal disturbances by water level cycles

PurposeApart from having high concentrations of salt, some natural saline wetlands also go through cyclical fluctuations in water level. They are frequently considered vulnerable habitats. In the last decades, the reduction of rainfall in many areas, coupled with fertilizer overuse, is transforming wetlands, especially in climates with a pronounced dry season. We studied a seasonally flooded saline wetland, and focused on the changes in the microbial communities.MethodsHigh-throughput sequencing was used to explore the diversity and structure of the prokaryotic communities present in the surface sediments. A water and soil salinity gradient along different lagoons in the wetland complex was observed.ResultsSalinity affected both microbial richness and composition. The highest microbial richness was observed in lagoons with lower salinity. Statistical analysis suggests that the differences in community composition were associated with differences in salinity level, although an anthropic disturbance (increasing levels of soil organic matter, SOM) that was present predominantly in one lagoon also had a noticeable effect. Sorting of samples using beta diversity distances revealed that differences among communities were due to the distinct habitats, that is, a lagoon’s salinity and SOM, not water level cycles. Differences between flooded and dry-out seasons were also explored and the linear model showed that only a small number of OTUs (2.5%) had statistical differences between seasons.ConclusionOur findings will help in understanding the effects that both salinity and drying-out periods, which are increasing problems worldwide, may have on microbial communities and their resistance to seasonal fluctuations in water levels.

Saltmarsh vegetation and social environment influence flexible seasonal vigilance strategies for two sympatric migratory curlew species in adjacent coastal habitats

BackgroundAnimals need to adjust their vigilance strategies when foraging between physically contrasting vegetated and non-vegetated habitats. Vegetated habitats may pose a greater risk for some if vegetation characteristics function as a visual obstruction but benefit others if they serve as protective shelter. Variation in group size, presence of similar species, along with variation in environmental conditions and anthropogenic disturbance can also influence vigilance investment.MethodsIn this study, we quantified the vigilance behaviour of two large-bodied, sympatric migratory curlew species—Far Eastern Curlew (Numenius madagascariensis) and Eurasian Curlew (N. arquata)—in vegetated Suaeda salsa saltmarsh and non-vegetated mudflat habitat in Liaohekou National Nature Reserve, China. We used linear mixed models to examine the effects of habitat type, season, tide time, flock size (conspecific and heterospecific), and human disturbance on curlew vigilance investment.ResultsBoth species spent a higher percentage of time under visual obstruction in S. salsa habitat compared to mudflat habitat but in response, only Far Eastern Curlew increased their percentage of vigilance time, indicating that visual obstruction in this habitat is only a concern for this species. There was no evidence that S. salsa vegetation served as a form of cryptic background colouration since neither species decreased their vigilance effect in S. salsa habitat in spring compared to the autumn migration season. The effect of curlew social environment (i.e. flock size) was habitat dependent since percentage of vigilance time by curlews in saltmarsh increased with both the number of individual curlews and number of other birds present, but not in mudflat habitat.ConclusionsWe conclude that both migratory curlew species exhibit a flexible vigilance adjustment strategy to cope with the different environmental and social conditions of adjacent and sharply contrasting coastal habitats, and that the trade-off between the risks of foraging and the abundance of prey may be a relatively common phenomenon in these and other shorebird populations.

PERANCANGAN SISTEM PAKAR UNTUK MENGIDENTIFIKASI GANGGUAN PADA TANAMAN JAMBU AIR MENGGUNAKAN METODE CERTAINTY FACTOR

The state of Indonesia, especially in the area of Central Java, is one of the largest producers of water guava. Some farmers rely on the results of guava cultivation as the basis for the family's economy because the guava harvest is quite promising. However, in certain seasons, water guava plants are often attacked by various kinds of pest and disease season disturbances. So that it can reduce crop yields or even cause crop failure. To overcome this problem, fast and precise action is needed so that the guava plant is protected from various kinds of pests and diseases. The method of developing an expert system for disturbance in water guava plants is the best solution in order to identify disturbances in water guava plants as early as possible. The method used in this expert system is the certainty factor method. With this method, several experts are needed to provide data related to disturbances in water guava plants. The expert system for guava plant disorders is designed using a web-based PHP programming language. In designing the knowledge base, which is the core of this system, is made dynamically to make it easier to add new data.

Facets of diatom biology and their potential applications

Diatoms are the reservoir of bioactive compounds which have immense application in nutrition, industrial commodities and ecological studies. In the oceans, diatoms form a large bloom of silica under favourable conditions, whereas, in lentic and lotic systems, they colonize according to seasonal disturbances. Notably, the survival of diatoms in a stressed environment is because of their uniqueness; therefore, diatoms serve as an ideal candidate to understand the evolutionary paradigm and successional dynamics. This review outlines the biological uniqueness of diatoms, their role in biogeochemical cycles and the recolonization pattern of diatoms in anthropic disturbed habitats. Furthermore, a detailed discussion on different technologies for extracting valuable biomolecules with an emphasis on lipid extraction has been carried out. Moreover, the diatom-based photosynthetic biorefinery approach for a better understanding of the renewable usage of biomass is done.

Seasonal Disturbances : Environment, Climate Change, and Anthropocene Poetics of Relation in Karen McCarthy Woolf's Poetry

Seasonal Disturbances : Environment, Climate Change, and Anthropocene Poetics of Relation in Karen McCarthy Woolf's Poetry

<em>Seasonal Disturbances</em>: Environment, Climate Change, and Anthropocene Poetics of Relation in Karen McCarthy Woolf's Poetry

<em>Seasonal Disturbances</em>: Environment, Climate Change, and Anthropocene Poetics of Relation in Karen McCarthy Woolf's Poetry

Seasonal Disturbances: An Interview with Poet Karen McCarthy Woolf

Seasonal Disturbances: An Interview with Poet Karen McCarthy Woolf Yvonne Reddick Yvonne Reddick yreddick@uclan.ac.uk Search for other works by this author on: Oxford Academic Google Scholar ISLE: Interdisciplinary Studies in Literature and Environment, isaa052, https://doi.org/10.1093/isle/isaa052 Published: 15 December 2020 Article history Received: 21 November 2019 Revision received: 11 February 2020 Accepted: 05 June 2020 Published: 15 December 2020