Moist moss tundra on Kapp Linne, Svalbard is a net source of CO₂ and CH₄ to the atmosphere

We measured CO2 and CH4 fluxes using chambers and eddy covariance (only CO2) from a moist moss tundra in Svalbard. The average net ecosystem exchange (NEE) during the summer (June–August) was −0.40 g C m−2 day−1 or −37 g C m−2 for the whole summer. Including spring and autumn periods the NEE was reduced to −6.8 g C m−2 and the annual NEE became positive, 24.7 gC m−2 due to the losses during the winter. The CH4 flux during the summer period showed a large spatial and temporal variability. The mean value of all 214 samples was 0.000511 ± 0.000315 µmol m−2s−1 which corresponds to a growing season estimate of 0.04 to 0.16 g CH4 m−2. We find that this moss tundra emits about 94–100 g CO2-equivalents m−2 yr−1 of which CH4 is responsible for 3.5–9.3 % using GWP100 of 27.9 respectively GWP20. Air temperature, soil moisture and greenness index contributed significantly to explain the variation in ecosystem respiration (Reco) while active layer depth, soil moisture and greenness index were the variables that best explained CH4 emissions. Estimate of temperature sensitivity of Reco and gross primary productivity showed that a modest increase in air temperature of 1 degree did not significantly change the NEE during the growing season but that the annual NEE would be even more positive adding another 8.5 g C m−2 to the atmosphere. We tentatively suggest that the warming of the Arctic that has already taken place is partly responsible for the fact that the moist moss tundra now is a source of CO2 to the atmosphere.

The Effect of Greenness Index on Case Fatality Rate of Covid-19 Analyzed by Using Landsat-8 Image (Case Study: DKI Jakarta)

COVID-19 is spreading into Indonesia and has reached tens of thousands of cases as of September 30, 2020. It was recommended by the American Public Health Association and the Centers for Disease Control and Prevention to remain physically active during COVID-19 quarantine by regularly visiting parks and green spaces as it can protect the body against the consequences of quarantine impacting physical and mental health. In this research, green space was monitored by using remotely sensed data. The green space distribution was obtained from the calculation of the Greenness Index from Landsat-8 Surface Reflectance Tier 1 satellite imagery processed through the Google Earth Engine platform. This study was conducted to determine the value of Greenness Index (GI), Case Fatality Rate (CFR) value due to COVID-19, and the relationship between them in 42 sub-districts in DKI Jakarta in the period of April to September 2020. Twenty-eight subdistricts (67%) showed negative correlation values that indicated that more green space in a region affects lower CFR growth.

By-Plant Prediction of Dry Matter Yields at Various Growth Stages of Maize Plants (Zea mays L.) Using Leaf Greenness Indicator in Climatic Conditions of Poland

Predicting yield at an early growth stage allows one to optimize the amount and timing of nitrogen fertilization to maximize crop yield. The aim of the study was to determine how different nitrogen doses would affect the nutrition of two maize varieties (Zea mays L.) with this element and their yields, and to demonstrate the potential of using the SPAD index as an early-stage predictor of dry matter yield (DMY) of maize biomass. The field experiment, with different pre- and post-sown N fertilizer doses, was conducted for two years in Poland. The two-factor experiment was set up in a randomized block design with three field replicates. There were four mineral fertilization variants: (I) 120 kg N·ha−1 without P and K fertilization, (II) 120 kg N·ha−1 + PK, (III) 160 kg N·ha−1 + PK, and (IV) 200 kg N·ha−1 + PK. The second-order factor was two stay-green maize varieties: Delitop (FAO 240) and Magitop (FAO 270). The mean values of the SPAD index of maize depended on the nitrogen dose. When the dose was increased from 120 kg·ha−1 to 200 kg·ha−1 with constant P and K fertilization, the value of the leaf greenness index increased significantly. The plants of both maize varieties fertilized with nitrogen at a dose of 120 kg N·ha−1 without P and K were characterized by the lowest values of the SPAD index, regardless of the year of the experiment. When the nitrogen dose was supplemented with P and K, the plants’ nutrition with nitrogen improved significantly. The values of the SPAD index in the maize plants of the variety Magitop were significantly greater than in the plants of the variety Delitop. The coefficients of correlation calculated for both maize varieties were highly significant at all measurement dates. Therefore, it is possible to conclude that the SPAD leaf greenness index can be used as an important, reliable, and non-invasive indicator for maize yield prediction. Nutrition of maize plants with nitrogen proved to be the main determinant of variability of the biomass yield. For this reason, it was the basis for the verification of individual mineral fertilization variants. The lack of phosphorus and potassium in the dose of mineral fertilizer limited the yield regardless of the variety, as compared to the variant that was optimally balanced with the nitrogen dose.

Influence of Spatial Resolution for Vegetation Indices’ Extraction Using Visible Bands from Unmanned Aerial Vehicles’ Orthomosaics Datasets

The consolidation of unmanned aerial vehicle (UAV) photogrammetric techniques for campaigns with high and medium observation scales has triggered the development of new application areas. Most of these vehicles are equipped with common visible-band sensors capable of mapping areas of interest at various spatial resolutions. It is often necessary to identify vegetated areas for masking purposes during the postprocessing phase, excluding them for the digital elevation models (DEMs) generation or change detection purposes. However, vegetation can be extracted using sensors capable of capturing the near-infrared part of the spectrum, which cannot be recorded by visible (RGB) cameras. In this study, after reviewing different visible-band vegetation indices in various environments using different UAV technology, the influence of the spatial resolution of orthomosaics generated by photogrammetric processes in the vegetation extraction was examined. The triangular greenness index (TGI) index provided a high level of separability between vegetation and nonvegetation areas for all case studies in any spatial resolution. The efficiency of the indices remained fundamentally linked to the context of the scenario under investigation, and the correlation between spatial resolution and index incisiveness was found to be more complex than might be trivially assumed.

Psychophysiological Response According to the Greenness Index of Subway Station Space

This study proposed a plan for implementing a pleasant and healthy indoor landscape in subway station space. To this end, it established a 3D landscape model of the subway interior by reviewing previous studies on indoor landscape and the greenness index of indoor spaces. Moreover, it investigated and analyzed psychophysiological responses of users to environmental indoor landscape design in subway station space. Subway stations were classified as underground subway stations and ground subway stations according to the presence of natural light inflow. The greenness index of indoor spaces was also divided into four types of 0%, 10%, 15%, and 20%. Through this process, eight 3D landscape models of the subway interior were implemented. In addition, this study investigated psychophysiological responses of 60 male and female adults in their 20s and 30s using the models implemented. The investigation result was analyzed based on a frequency analysis, the χ2 test, T-test, one-way analysis of variance, and multidimensional scaling, which were performed in SPSS Statistics 25. The results of this study can be summarized as follows. First, physiological responses of research subjects were analyzed based on their prefrontal α wave asymmetric values. The analytic result showed that the environment where interior landscape was adopted produced more positive effects than the environment where interior landscape was not adopted. Second, psychological responses of research subjects were examined based on their greenness index preference, awareness of interior landscape area, attention restoration effect, and space images. The analytic result indicated that, among eight 3D landscape models of the subway interior, they preferred the model with the greenness index of 15% for underground subway stations. In addition, they preferred the model with the greenness index of 10% the most for ground subway stations.

SPAD Leaf Greenness Index: Green Mass Yield Indicator of Maize (Zea mays L.), Genetic and Agriculture Practice Relationship

The study presents the results of two field studies (Experiment I, Experiment II), whose aim was to assess the impact of agriculture factors on maize green mass and leaf greenness index (Soil and Plant Analysis Development, SPAD) in critical growth stages, as well as to determine the relationship between the SPAD index and the yield of green maize for ensiling. It was shown that thermal and humidity conditions in maize growing seasons determined the value of the SPAD leaf greenness index and the yield of maize harvested for silage. Row application of mineral fertilizer (N, NP) and selection of “stay-green” varieties guarantee a higher yield of maize green mass. Growing maize in direct sowing reduces chlorophyll content expressed in SPAD units, thereby reducing plant nitrogen condition, which significantly decreases the yield of biomass intended for silage. The SPAD leaf greenness index determined in critical stages of maize growth can be considered as a yield predictor of green mass for ensiling. The examined maize cultivars were divided into two groups on the basis of hierarchically grouping using the unweighted pair group method of arithmetic means. The first group comprised cultivars SY Cooky and Drim “stay-green,” while the second one included cultivars ES Paroli “stay-green” and ES Palazzo.

Influence of Silver Nanoparticles, Laser Light and Electromagnetic Stimulation of Seeds on Germination Rate and Photosynthetic Parameters in Pumpkin (Cucurbita pepo L.) Leaves

The study aimed to determine the impact of laser light (L), magnetic stimulation (p) and silver nanocolloid (AgNC) on pumpkin seeds on the germination rate and content of photosynthetic pigments as well as the efficiency of photosynthesis and greenness index in the plant’s development stages. Seeds germinated after the use of various combinations of different refining techniques. The best results were observed for the alternating magnetic field, where the germination energy increased significantly by 20% relative to the control. A similar effect was observed in terms of germination capacity which increased by 4%. A decrease in terms of emergence rate was observed in all study groups. Leaves grown from seeds soaked in nanocolloidal silver on platters were characterised by a significantly higher content of chlorophyll a and b by, respectively, 53 and 11%, as well as 79% higher carotenoid content. The leaves of potted plants contained 42 and 43% more chlorophyll a in groups p and AgNC. In addition, 66 and 81% more carotenoids in groups L and p. At the stage of the onset of flowering of pumpkin, an improvement in terms of photosynthetic efficiency and greenness index was observed in all study groups. The highest improvement was recorded for seeds soaked in silver and reached 23% (intensity of photosynthesis) and 11% (greenness index SPAD).

Response of Interspecific Geraniums to Waste Wood Fiber Substrates and Additional Fertilization

Promotion of sustainable horticulture via wider use of peat substrate substitutes makes wood fiber an increasingly popular substrate component. Interspecific geraniums are plants of huge potential in the floriculture market, but there are not enough specific guidelines on their cultivation. This study investigated the effectiveness of enriching peat substrate with 10%, 20%, 30%, or 40% (by volume) waste wood fiber in the pot cultivation of interspecific geraniums cv. ‘Calliope Dark Red’. It also examined plant response to additional fertilization with nitrogen in the form of Ca(NO3)2. Plants grown in the substrate with 10% and 20% of wood fiber did not differ in the leaf greening index, flower weight, and visual score from the plants grown in control (100% peat substrate). Wood fiber content of 40% negatively affected all growth parameters and leaf content of macro- and micronutrients. The plants growing in the peat substrate enriched with 20% of waste wood fiber and fertilized with nitrogen had the highest leaf greenness index, the greatest number of flowers, and the highest content of N, P, Ca, Na, Fe, Mn, Cu, and Zn. In summary, the study demonstrated that high quality ornamental plants can be successfully grown in peat substrate containing 20% of waste wood fiber and additionally fertilized with nitrogen.