Micrometeorological conditions of the soloteca of Embrapa Solos -Rio de Janeiro, Brazil

Soloteca is the term used in Brazil to refer to the place where reference soil samples are stored. The Soloteca of Embrapa Solos-RJ, for example, stores soil samples from different regions of Brazil, and these samples need to be stored in conditions that preserve their intrinsic characteristics. In this context, the objective of this work was to determine the air temperature and relative humidity conditions in the Soloteca of Embrapa Solos-RJ. The data were collected by three Thermo hygrometers, installed inside and outside the place where the samples are stored, in the period from December 1, 2016, to March 31, 2017, corresponding to summer 2016/17. The difference between the mean and variance of the data for each environment/height was evaluated at the 5% level, respectively, by the t-Student and Snedecor's F tests. The other statistical analyses were presented by boxplots. It was observed that the air temperature, on average, did not differ between the indoor and outdoor environments at a height of 1.6 meters, but there was a difference with the sensor installed near the surface (0.5 meters). On the other hand, the dispersion of the data attested by the variance and the coefficient of variation in the external environment was greater than those recorded internally.

Ecology of the cold-adapted species Nebria germari (Coleoptera: Carabidae): the role of supraglacial stony debris as refugium during the current interglacial period

In the current scenario of climate change, cold-adapted insects are among the most threatened organisms in high-altitude habitats of the Alps. Upslope shifts and changes in phenology are two of the most investigated responses to climate change, but there is an increasing interest in evaluating the presence of high-altitude landforms acting as refugia. Nebria germari Heer, 1837 (Coleoptera: Carabidae) is a hygrophilic and cold-adapted species that still exhibits large populations on supraglacial debris of the Eastern Alps. This work aims at describing the ecology and phenology of the populations living on supraglacial debris. To this end, we analysed the populations from three Dolomitic glaciers whose surfaces are partially covered by stony debris. We found that supraglacial debris is characterised by more stable colder and wetter conditions than the surrounding debris slopes and by a shorter snow-free period. The populations found on supraglacial debris were spring breeders, differently from those documented in the 1980s on Dolomitic high alpine grasslands, which were reported as autumn breeders. Currently, Nebria germari seems, therefore, to find a suitable habitat on supraglacial debris, where micrometeorological conditions are appropriate for its life-cycle and competition and predation are reduced.

Soil-Surface Straw Influences Micrometeorological Conditions Affecting Canola Mortality During Nighttime Frosts

Our objective was to measure alterations in the micrometeorological conditions surrounding canola seedlings during frost periods, and to quantify seedling mortality as a function of straw distribution on the ground surface. The data was acquired from 15 frosts in 2014. We used four treatments, comprising ground surface without straw (SWS), ground surface entirely straw-covered (SEC), sowing line without straw (SLW), and soil with preexisting surface straw (SES), over three experiments. Net radiation (NR), soil heat flux (G), air (Ta), leaf (Lf), rosette (Tr), and surface temperature (Ts), and plant mortality were evaluated. NR was higher in the SEC treatment and lower in the SLW treatment, whereas G was higher on straw-covered ground; Ts and Ta were lower in the SEC than in the other treatments during the most intense frosts. On 06/19, Tr in the SEC and SLW treatments was -0.66 °C and 0.42 °C, respectively; on 08/14, Lf was -3.62 °C and -2.88 °C in the SEC and SLW treatments, respectively. Plant mortality due to the frost on 06/19 was 30% in the SEC treatment, but 0% in the SLW treatment; the frost of 08/14 caused 33.8% mortality in the SEC treatment and 1.25% in the SLW treatment. This therefore showed that removing straw from the sowing line improved the microclimate around the plants, thus reducing canola mortality at the beginning of the growth cycle, which is when frost events most frequently occur.

Puccinia sambuci Infection of American Elderberry Plants

Elderberry rust (Puccinia sambuci Schwein.) Arthur (=P. bolleyana) (Arthur, 1921) disease is frequently found in commercial American elderberry (Sambucus nigra L. subsp. canadensis L.) plantings when an alternate host, Carex sp., is present. To evaluate potential infection periods of P. sambuci on elderberry plants, micrometeorological conditions were monitored. Rust symptoms were observed on elderberry on 5 Apr. 2016, and conditions favorable for possible infection were 9 to 18 °C, ≥3 hours of continuous leaf wetness, and ≥85% relative humidity. Studies were also conducted to ascertain whether P. sambuci with varying pustule numbers affects fruiting, berry puree quality, or vegetative growth. Fruit yield was reduced by 31% when potted ‘Bob Gordon’ elderberry averaged six rust pustules per plant compared with noninfected plants. In another experiment, field-grown ‘Wyldewood’ plants averaging 137 rust pustules/cane at harvest had 47% less fruit weight on canes than uninfected canes. Titratable acidity of fruit puree from plants was lower when plants had either 690 rust pustules/plant or 137/pustules/cane, but soluble solids and pH of puree were unaffected by P. sambuci infection. The effect of rust infection on vegetative growth of elderberry plants also varied with pustule numbers. With a low infection level (six pustules per plant), P. sambuci did not induce premature leaf loss on ‘Bob Gordon’ plants or adversely affect shoot dry weight at the end of the growing season. When P. sambuci infection on ‘Wyldewood’ plants was more severe (137 pustules/cane), greater leaf loss occurred on infected canes than on uninfected canes. At very high infection levels (690 pustules/plant), ‘Bob Gordon’ plant dry weight was reduced. Because of the potential for fruit yield loss on elderberry plants, control of P. sambuci at relatively low infection levels on this plant may be warranted. Strategies that eliminate or suppress the alternate host would likely reduce the P. sambuci inoculum and limit the potential for elderberry plant infection.

Forest harvesting impacts on micrometeorological conditions and sediment transport activities in a humid periglacial environment

Sediment transport activities in the periglacial environment are controlled by hillslopes micrometeorological conditions (i.e., air and ground temperatures, ground water content), which are highly affected by vegetation cover. Thus, there is a possibility that forest harvesting, which is the most dramatic change to vegetation cover in mountain areas, may severely impact sediment transport activities in periglacial areas (i.e., soil creep, dry ravel). Knowledge of the effects of forest harvesting on sediment transport are needed to protect aquatic ecosystems as well as to develop better mitigation measures for preventing sediment disasters. In this study, we investigated changes in sediment transport activities following forest harvesting in steep artificial forests located in a humid periglacial area of the Southern Japanese Alps. In the Southern Japanese Alps, rainfall is abundant in summer and autumn, and air temperatures frequently rise above and fall below 0 degrees in the winter. Our monitoring by time laps cameras revealed that gravitational transport processes (e.g., frost creep and dry ravel) dominate during the freeze-thaw season, while rainfall-induced processes (surface erosion and soil creep) occur during heavy rainfall seasons. Removal of the forest canopy by forest harvesting alters the type of winter soil creep from deeper frost creep to diurnal needle-ice creep. Winter creep velocity of the ground surface sediment in the harvested site was significantly higher than that in the non-harvested site. Meanwhile, sediment flux on the hillslopes observed by sediment traps decreased in the harvested site. Branches of harvested trees left on the hillslopes captured sediment coming from upslope. In addition, the growth of understories after harvesting possibly reduced surface erosion. Consequently, removal of the forest canopy by forest harvesting directly impacts micrometeorological conditions and periglacial sediment transport activity, while sediment flux on hillslopes is also affected by branches left on the hillslopes and recovery of understories.

Microclimate Variation among Urban Land Covers: The Importance of Vertical and Horizontal Structure in Air and Land Surface Temperature Relationships

Air and land surface warming effects from urbanization are of increasing concern because of expanding heat-related impacts on human health. Many studies have investigated land-cover effects on air temperature Ta or land surface temperature (LST) individually, but relatively few studies have examined the relationships between these two heat indicators and other meteorological variables. The authors investigate how land cover influences local distributions of LST, Ta, and relative humidity (RH) and their interactions. During July 2016, 30 Ta and RH sensors were deployed at two heights above the ground (0.1 and 1.5 m) along with a thermal camera and an anemometer to quantify the influence of surface dynamics on atmospheric micrometeorological conditions. Sensors were distributed in Riverside, California, over five common urban land covers: asphalt, bare surface, turf grass, short trees, and tall trees. Stronger Ta–LST relationships were observed at 0.1 m for asphalt, bare surface, and grass and at 1.5 m for short and tall trees. Excluding grass, greater Ta–LST differences were found for daytime than for nighttime. To add to the complexity of Ta–LST relationships, increasing spatial variation in LST during the day for short- and tall-tree land covers were found. Furthermore, both wind velocity and LST were correlated with Ta vertical distributions. Higher RH and lower LST, Ta, and vapor pressure deficit were found in vegetated covers. Through the use of thermal imagery and meteorological measures, it was found that distinct land-cover influences on microclimate exist and that estimates of urban Ta using LST may improve with the use of land-cover-specific relationships.