Assessing the equilibrium between assemblage composition and climate: A directional distance-decay approach.

An experiment was carried out at the Regional Sugarcrop Research Station (RSRS) farm, Thakurgaon under the agro-ecological zone of Old Himalayan Piedmont Plain (AEZ-1) of Bangladesh, during 2016-2017 to 2017-2018 cropping seasons to evaluate the impact of row orientation on the productivity of sugarcane with potato as intercrop. Under the study eight treatments viz T1: Single row cane (SRC) only in north-south direction, T2: SRC + potato in North-South direction, T3: SRC only in east-west direction, T4: SRC + potato in east-west direction,T5: Paired row cane (PRC) only in North-South direction, T6: PRC + potato in north-south direction, T7: PRC only in east-west direction and T8: PRC + potato in east-west direction were tested following Randomized Complete Block Design with three replications Significant differences were found among the observed parameters except germination (%) of setts, number of internodes per stalk and unit stalk weight of sugarcane. The highest number of tiller and millable cane population, cane yield and brix reading were achieved from the treatment SRC + potato in the North-South direction. The highest intercrop yield, equivalent cane yield of intercrop, total adjusted yield and gross return were obtained from the treatment PRC + potato in north-south direction, but the highest net return and benefit cost ratio were obtained from the treatment SRC + potato in the North-South direction. Having the highest cane yield, net return and benefit cost ratio with less variable cost, sugarcane planting in a single row system with potato as intercrop in a North-South row direction could be considered the best package practice for successful sugarcane farming. Bangladesh Agron. J. 2024, 26(2): 7-15

<p>So-called Intensives are one-hour-long VLBI sessions including mostly two stations, which are routinely observed to derive the Earth's phase of rotation expressed through the parameter UT1-UTC. Due to the limitation in time and participating stations, only a few parameters of interest can be estimated during the analysis, whereas others are fixed to their a priori values, such as the remaining Earth orientation parameters, as well as station and source coordinates. </p><p>It is common knowledge that the impact of errors in the a priori station coordinates on the UT1-UTC results changes depending on the location, orientation and length of the baseline. In this presentation, we examine these effects for the first time in a systematic way covering the whole Earth. We performed Monte-Carlo simulations (MCS) with realistic noise models for a global 10° grid of artificial VGOS stations. The grid covers latitudes of -80° to 80° and longitudes of 0° to 180°. All possible and unambiguous baselines between these artificial telescopes are investigated. For every baseline, monthly schedules were generated over one year to eliminate source selection effects. In the MCS, the station coordinates are compromised with an error of 5 mm in either North-South, East-West or Up-Down direction. </p><p>Thereby, we demonstrate that errors along the East-West direction tend to be less critical for long East-West baselines compared to errors in North-South direction. Furthermore, we show that errors in the station height are less critical compared to errors in North-South or East-West direction. The simulation results show that investigations of suitable locations for additional radio telescopes for UT1-UTC Intensive sessions cannot be selected by investigations in analytical equations such as the partial derivatives of the parameters alone but need more sophisticated analyses of error propagation.</p>

In the holes under the ground, temperature is low and soil is humid even in summer, and wind is soft. Aiming to use these phenomena to protect crops from hot and strong wind, experiments were conducted in Okinawa located in a subtropical region in Japan in 2000 summer. Trenches of north-south and east-west directions, deep (1.0 m) and shallow (0.5 m), with 1.2 m wide, were constructed. Cultural beds were prepared both sides of trench bottoms. Kidney bean (Phaseolus vulgaris L.) and turnip (Brassica Rapa L.) were sown on beds in trench and a conventional flat bed mid summer. Trench beds were superior in germination and growth to the conventional bed. Deep trench beds were superior in germination and growth to shallow ones. In beds of the north-south direction trenches, the east sides and the west sides were superior in germination and growth, respectively. In beds of the east west direction trenches, the south sides were superior in germination and growth. The kidney bean yield was remarkable high in the west sides of the north-south direction trenches, and the south and north sides in the 1.0 m deep trench of east-west direction. The air temperature difference was not found between trenches and the conventional. However, the soil temperature was lower and soil water was more in the trenches than in the conventional. In beds of the north-south direction trenches, soil temperature in the west side was hastened to increase, and that in the east side delayed increasing. In beds of the east-west direction trenches, soil temperature in the south side were lower than in the north side. The soil water contents were higher in the trenches than in the conventional, in the deep trenches than in the shallow ones. In the trenches of the same depth, soil water contents were as following, the east-west direction south sides > the east-west direction north sides > the north-south direction east sides = the north-south direction west sides. Trenches soften wind velocities. Soil temperatures increasing in trenches were suppressed by shading and water evaporation. Soil water, the cooling source, was transferred from soil beside the trench to the trench bottom. Using and improving the heterogeneous environment in trenches, crop would be protected from hat and strong wind without energy use and with less money. We propose a trench house equipping a movable roof to protect crops from heavy rain and extra strong wind.

The objective of this work was to evaluate the variations of environmental factors under the canopy of papaya planted in a north-south and east-west orientation. Two areas were studied, one oriented north-south and the other east-west, both planted with a spacing of 3.20 mx 2.40 m, planted in April 2015. The distances from the papaya line (levels of shading) and a place in full sun, where it was evaluated, in the North-South direction: in the papaya planting line, at 40 cm west side, 40 cm east side and in full sun; in the East-West direction: In the papaya planting line, at 40 cm on the north side, 40 cm on the south side and in the planting line in full sun. The following atmospheric variables were determined: temperature, irradiance and relative humidity. Tukey's test was used to compare means at a confidence level of 95%. Papaya planted in the east-west direction, under the conditions studied, provided lower incident irradiation, reduced temperature and higher values ​​of relative humidity under its canopy, compared to papaya planted in the north-south direction. It is possible to intercrop papaya planted in the east-west direction with other agricultural crops, including conilon coffee.

Parasite communities of Raneya brasiliensis are described and its parasites used as biological tags to discriminate its populations. Fish were caught in two zones of the Argentine Sea: one sample from San Jorge Gulf (Patagonian Region) and three samples from off the coast of Buenos Aires (Bonaerense Region). A total of 183 fish were examined for parasites and 11 species were found. Host body size and its ecology are pointed out as drivers of the paucity of taxa found. Multivariate similarity analyses allowed the identification of three stocks: one in the San Jorge Gulf, and two other in the Bonaerense Region. The parasite species that contributed most to the separation of the samples were generally those identified as biological markers in previous studies in the area. Patterns of distance decay in similarity among communities in R. brasiliensis were found; with dissimilarity values between distant localities being higher than between close ones. Whereas the composition and structure of parasite assemblages in Bonaerense waters reflect those of other fish species in this region, being mainly determined by the composition of the compound community, no repeatable patterns were found in the composition of parasites assemblages when R. brasiliensis was compared with other hosts species in Patagonia.

Studies of soil bulk density (BD) spatial variations of land reclaimed after mining have become a focus of land reclamation and ecological restoration research. However, there have been few studies on the relationship among the reconstructed BD, terrain conditions, and vegetation growth. We examined the southern dumping site of the Pingshuo Antaibao open-pit coal mine located in a loess area in China. Field sampling data, digital elevation models (DEMs), and high-definition images were obtained, and indoor testing, geostatistics, and inverse distance weighting (IDW) were applied. This paper aims to analyze the spatial distribution law of the reconstructed BD and focus on its relationship with slope and vegetation allocation models. We demonstrated that (1) BD increased with soil depth and varied moderately within each layer. (2) The BD variation amplitude of the top 0-20-cm soil layer in both the east-west and south-north directions was small and more similar in the east-west direction than in the south-north direction, which was affected by herbaceous root systems. In the next four layers from 20 to 60 cm, the variation in BD in the east-west direction was far larger than that in the south-north direction, which was affected by vegetation classification. (3) On the whole, BD decreased with increasing slope, but when the slope was between 0° and 21°, BD exhibited a specific change law. (4) From the perspective of vegetation classification, the orders of magnitude of BD in the 0-20-cm and 20-60-cm layers differed. Overall, BD in areas vegetated with Korshinsk Peashrub was the lowest, and BD was moderate in areas with mixed vegetation, while BD was the highest in areas without vegetation or only vegetated with Black Locust. The mixed grass-bush-tree or bush-tree mode attained the best effect in regulating BD. These results can improve the basic principles of land reclamation in mining areas and provide a basis for further optimizing land reclamation technology in practice.

This investigation has been conducted to quantitatively evaluate the possible variation tendencies of some important physical properties such as bulk density and water contents of field soils with distance. The experiment was set up on Arlk soil series situated on Ç.Ü. Faculty of Agriculture Experimental Farm. Soil samples were taken at 5 m intervals on two 100 m transacts placed in North-South and East-West directions. The sampled soil depths were 0-20, 20-40 and 40-60 cm in the directions of North-South and 0-20 cm in that of East-West: yielding a total of 80 soil samples. The variation tendencies of above mentioned soid properties were quantitatively evaluated semi-variograms and it was found that the variability is dependent on the sampling interval. The sampling interval for a reliable estimation of bulk density was 40 m in North-South and 30 m in East-West directions: and for soil moisture contents it was 20 m in North-South directions and 25 m in East-West directions.

Large regions of the North American mid-continent are underlain by Precambrian layered rocks buried beneath Phanerozoic sedimentary strata. South of the Wichita Mountains, published seismic reflection profiles show a Precambrian layered assemblage extending for at least 40 km in both the north-south and east-west directions, and industry data show that it may continue 150 km to the southeast. Seismic reflection data in the Illinois region show a Precambrian layered assemblage extending 320 km in an east-west direction and 200 km in a north-south direction. In both cases, the layered rocks are as much as 12 km thick. Apparent sequence boundaries (onlap, downlap) within these assemblages suggest they are parts of large depositional basins with diffractions and dipping strat due to faulting. The layered sequences correlate with regions of relatively long-wavelength and low-amplitude magnetic anomalies; the extent of this magnetic signature suggests that about 200,000 km{2} of Illinois, Indiana, and western Ohio, about 50,000 km{2} of southernmost Oklahoma and north-central Texas, and about 32,000 km{2} of southern Missouri and northern Arkansas may be underlain by similar Precambrian strata. Drill holes indicate that the top of the mid-continent Precambrian basement is composed largely of silicic igneous rocks. Such material may comprise a large part of the layered sequences. Alternatively, these igneous rocks could be intermixed with, or underlain by, nonvolcanic (meta?)sedimentary strata. The strong reflectivity of some layers suggest that minor mafic flows and/or sills may also be present. Analysis of U/Pb and Nd/Sm isotopes within the granites and rhyolites imply that the layered sequences postdate crustal formation at 1.7-2.0 Ga and predate or are contemporaneous with the 1.3-1.5 Ga crystallization ages of the granites and rhyolites. Though these layered rocks have a spatial association with igneous rocks and thus have likely been metamorphosed, the possibility tha they contain Precambrian hydrocarbons that escaped heating is as yet untested.

We conducted a feasibility study to estimate the horizontal ion velocity field in the ionospheric F region from ion velocities observed by the EISCAT_3D radar. We assumed a 27-beam configuration with a minimum elevation angle of 30 degrees. The ion velocity observation data from 200 km to 500 km altitude were projected to 200 km altitude, assuming ions above 200 km altitude follow the E x B drift. Then, we reconstructed ion velocity vectors for ±250 km in the east-west direction and ±500 km in the north-south direction at 200 km altitude. The resolution in north-south and east-west directions was 25 km. The reconstruction was conducted by maximizing a posterior probability based on Bayes’ theorem. The constraints were set to minimize the L2 norms of the following four vectors in the horizontal plane: (1) the first and (2) the second derivative of three components of the ion velocity vector, (3) the divergence of the ion velocity perpendicular to the magnetic field lines, and (4) the ion velocity parallel to the magnetic field lines. We investigated which combination of the four constraints would reconstruct the shear flow field most correctly and found that the best combination was (2), (3), and (4).

Tree growth depends, among other factors, largely on the prevailing climatic conditions. Therefore, changes to tree growth patterns are to be expected under climate change. Here, we analyze the tree-ring growth response of three major European tree species to projected future climate across a climatic (mostly precipitation) gradient in northeastern Germany. We used monthly data for temperature, precipitation, and the standardized precipitation evapotranspiration index (SPEI) over multiple time scales (1, 3, 6, 12, and 24 months) to construct models of tree-ring growth for Scots pine (Pinus sylvestris L.) at three pure stands, and for common beech (Fagus sylvatica L.) and pedunculate oak (Quercus robur L.) at three mature mixed stands. The regression models were derived using a two-step approach based on partial least squares regression (PLSR) to extract potentially well explaining variables followed by ordinary least squares regression (OLSR) to consolidate the models to the least number of variables while retaining high explanatory power. The stability of the models was tested through a comprehensive calibration-verification scheme. All models were successfully verified with R²s ranging from 0.21 for the western pine stand to 0.62 for the beech stand in the east. For growth prediction, climate data forecasted until 2100 by the regional climate model WETTREG2010 based on the A1B Intergovernmental Panel on Climate Change (IPCC) emission scenario was used. For beech and oak, growth rates will likely decrease until the end of the 21st century. For pine, modeled growth trends vary and range from a slight growth increase to a weak decrease in growth rates. The climatic gradient across the study area will possibly affect the future growth of oak with larger growth reductions towards the drier east. For beech, site-specific adaptations seem to override the influence of the climatic gradient. We conclude that Scots pine has great potential to remain resilient to projected climate change without any greater impairment, whereas common beech and pedunculate oak will likely face lesser growth under the expected warmer and dryer climate conditions. The results call for an adaptation of forest management to mitigate the negative effects of climate change for beech and oak.

Community resilience after fire is determined by species' ability to regenerate through two main mechanisms growth of new sprouts (resprouter species) and germination from surviving seed banks or from seeds arriving from neighbouring populations (seeder species). Both the mechanisms are present in Mediterranean communities. The occurrence of both the types in a community depends on fire history and the bio-geographical history determining the available species pool. Regenerative traits also covary with other functional attributes associated with resource acquisition and stress tolerance. As post-fire regenerative responses can be related to various ecological factors other than fire, we tested the hypothesis of a different proportional representation of post-fire regenerative syndromes in forest woody species along a climatic gradient in Catalonia (NE Spain) ranging from Mediterranean to temperate-boreal climates. Specifically, we expected seeder species to become less common with colder and moister conditions while resprouters would not be so influenced by the climatic gradient. We also tested the hypothesis of change in the relative abundance of regenerative syndromes in relation to recent fire history. We analysed a large database obtained from extensive forestry surveys and remote sensing fire records. After correction for spatial autocorrelation, we found an increase in the proportion of seeder species under more Mediterranean conditions and a decrease in fire-sensitive species (with no efficient mechanisms of post-fire recovery) in moister conditions. Resprouter species were similarly present across the whole gradient. A similar pattern was observed after excluding recently burnt plots. Therefore, post-fire regenerative syndromes segregate along the climatic gradient. Recent fires reduced the occurrence of fire-sensitive species and increased the proportion of seeder species. No significant effect was observed on resprouter species. Fire has a sorting effect, shaping the occurrence of species with different regenerative traits. Overall, fire seems to explain better the variability of the proportion of fire-sensitive species and climate the variability of seeder species. In addition, other factors (forestry practices and the covariation between regenerative and functional attributes) are likely to contribute to the regional pattern of regenerative syndromes.

SummaryAimOur aim was to understand how similarity changes with distance in biological communities, to use the distance decay perspective as quantitative technique to describe biogeographic pattern, and to explore whether growth form, dispersal type, rarity, or support affected the rate of distance decay in similarity.LocationNorth American spruce‐fir forests, Appalachian montane spruce‐fir forests.MethodsWe estimated rates of distance decay through regression of log‐transformed compositional similarity against distance for pairwise comparisons of thirty‐four white spruce plots and twenty‐six black spruce plots distributed from eastern Canada to Alaska, six regional floras along the crest of the Appalachians, and six regional floras along the east–west extent of the boreal forest.ResultsSimilarity decreased significantly with distance, with the most linear models relating the log of similarity to untransformed distance. The rate of similarity decay was 1.5–1.9 times higher for vascular plants than for bryophytes. The rate of distance decay was highest for berry‐fruited and nut‐bearing species (1.7 times higher than plumose‐seeded species and 1.9 times higher than microseeded/spore species) and 2.1 times higher for herbs than woody plants. There was no distance decay for rare species, while species of intermediate frequency had 2.0 times higher distance decay rates than common species. The rate of distance decay was 2.7 times higher for floras from the fragmented Appalachians than for floras from the contiguous boreal forest.Main conclusionsThe distance decay of similarity can be caused by either a decrease in environmental similarity with distance (e.g. climatic gradients) or by limits to dispersal and niche width differences among taxa. Regardless of cause, the distance decay of similarity provides a simple descriptor of how biological diversity is distributed and therefore has consequences for conservation strategy.

This study focused on the monitoring of a bridge using the global navigation satellite system real-time kinematic (GNSS-RTK) sensor. An improved hybrid denoising method was developed to enhance the GNSS-RTK’s accuracy. The improved hybrid denoising method consists of the improved complete ensemble empirical mode decomposition with adaptive noise (ICEEMDAN), the detrended fluctuation analysis (DFA), and an improved wavelet threshold denoising method. The stability experiment demonstrated the superiority of the improved wavelet threshold denoising method in reducing the noise of the GNSS-RTK. A noisy simulation signal was created to assess the performance of the proposed method. Compared to the ICEEMDAN method and the CEEMDAN-WT method, the proposed method achieves lower RMSE and higher SNR. The signal obtained by the proposed method is similar to the original signal. Then, GNSS-RTK was used to monitor a bridge in maintenance and rehabilitation construction. The bridge monitoring experiment lasted for four hours. (Considering the space limitation of the article, only representative 600 s data is displayed in the paper.) The bridge is located in Tianjin, China. The original displacement ranges are −14.9~19.3 in the north–south direction; −26.9~24.7 in the east–west direction; and −46.7~52.3 in the vertical direction. The displacement ranges processed by the proposed method are −12.3~17.2 in the north–south direction; −24.6~24.1 in the east–west direction; and −46.7~51.1 in the vertical direction. The proposed method processed fewer displacements than the initial monitoring displacements. It indicates the proposed method reduces noise significantly when monitoring the bridge based on the GNSS-RTK sensor. The average sixth-order frequency from PSD is 1.0043 Hz. The difference between the PSD and FEA is only 0.99%. The sixth-order frequency from the PSD is similar to that from the FEA. The lower modes’ natural frequencies from the PSD are smaller than those from the FEA. It illustrates the fact that, during the repair process, the missing load-bearing rods made the bridge less stiff and strong. The smaller natural frequencies of the bridge, the complex construction environment, the diversity of workers’ operations, and some unforeseen circumstances occurring in the construction all bring risks to the safety of the bridge. We should pay more attention to the dynamic monitoring of the bridge during construction in order to understand the structural status in time to prevent accidents.

Sea ice motion (SIM) has significant implications for sea–air interactions, thermohaline circulation, and the development of the Arctic passage. This research proposes an improved SIM retrieval method from Fengyun-3D’s (FY-3D) microwave radiometer imager’s (MWRI) brightness temperature (Tb) data based on the modified classical maximum cross-correlation (MCC) method and the multisource data merging method. This study utilized buoy data to establish the search area range, applied distinct thresholds across various Arctic regions, and merged the buoy data, reanalysis wind data, and SIM retrieved from FY-3D/MWRI Tb data. In 2019, for the final Arctic SIM results retrieved from the MWRI 89 GHz and 36.5 GHz Tb data, the root-mean-square error (RMSE) and the mean average error (MAE) in the east–west direction were 2.07 cm/s and 1.38 cm/s and those in the north–south direction were 1.96 cm/s and 1.15 cm/s, compared to the ice-tethered profiler (ITP) data. Compared with the daily average data of the National Snow and Ice Data Center (NSIDC), the RMSE and MAE of the SIM results obtained in this study were 0.74 cm/s and 0.93 cm/s in the east–west direction, and 0.56 cm/s and 0.72 cm/s in the north–south direction, respectively. The monthly average of the SIM retrieved from the MWRI Tb data in this research also showed a good agreement with the monthly average of the NSIDC SIM product. The comparison showed that the MWRI Tb data could be used to retrieve the Arctic SIM, and the Arctic SIM retrieval method presented in this paper was accurate and general.

The diversity of a region reflects both local diversity and the turnover of species (beta diversity) between areas. The angiosperm flora of eastern Asia (EAS) is roughly twice as rich as that of eastern North America (ENA), in spite of similar area and climate. Using province/state‐level angiosperm species floras, we calculated beta diversity as the slope of the relationship between the log of species similarity (S ) and either geographic distance or difference in climate. Distance‐based beta diversity was 2.6 times greater in the north–south direction in EAS than in ENA and 3.3 times greater in the east–west direction. When ln S was related to distance and climate difference in multiple regressions, both distance and climate PC1 were significant effects in the north–south direction, but only geographic distance had a significant, unique influence in the east–west direction. The general predominance of distance over environment in beta diversity suggests that history and geography have had a strong influence on the regional diversity of these temperate floras.