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The wide variability in functional traits that enable the cosmopolitan distribution of lichens often includes the water storage capacity, S, of their thallus. Lichen S in forest canopies can be large enough to intercept and evaporate significant amounts of rainwater, contributing to the runoff-reduction ecosystem services provided by urban forests; however, S is likely influenced by the presence of air pollutants (polycyclic aromatic hydrocarbons, PAHs) in urban areas. PAHs, being both chemically hydrophobic and damaging to lichen thalli, are expected to reduce lichens’ S and, thereby, limit their contribution to hydrologic ecoservices of urban forests. Hence, the relationship between PAH accumulation and rainwater uptake was examined for two lichen species, common in urban forests around the world – Platismatia glauca and Pseudevernia furfuracea. Samples were collected from an area of low air pollution and another area in a highly urbanized city centre with high air pollution exposure (Kraków, Poland). Lichen S was determined using laboratory-simulated rainfall. PAH bioaccumulation differed between species and among the samples from clean and polluted environments. After exposure to polluted air, the concentration of PAHs was higher in P. glauca than P. furfuracea. Samples from the non-urban setting, however, showed no differences between the two species. In the case of P. glauca, S decreased from 35.8% in samples from clean environment to 8.3% after six months of exposure in the urban setting. The respective S values for P. furfuracea were 25.4% and 12.4%. Results strongly suggest that PAH exposure reduces S in both lichen species.

Background: Changes in rainfall induced by climate change will likely influence the utilization of water resources and affect the nutrient cycle in plants in the water-limited desert steppe. In order to understand the response of nitrogen and phosphorus resorption characteristics of plant leaves to precipitation changes, this study compared the nitrogen (N) resorption efficiency, phosphorus (P) resorption efficiency and influencing factors of plants in a desert steppe through water treatment experiments. Methods: A 4-year field experiment was performed to examine the response and influencing factors of nitrogen (N) and phosphorus resorption efficiency of five dominant plants in Stipa breviflora desert steppe to simulated precipitation change in Inner Mongolia, with four simulated precipitation gradients including reducing water by 50%, natural precipitation, increasing water by 50%, increasing water by 100%. Results: Compared with natural precipitation, increasing water by 100% significantly increased soil moisture, and significantly increased the aboveground biomass of S. breviflora, C. songorica, A. frigida, decreased the N concentrations in green leaves of S. breviflora, Cleistogenes songorica, Artemisia frigida, Kochia prostrata, decreased the N concentrations in senesced leaves of C. songorica, decreased the P concentrations in green leaves of K. prostrata and Convolvulus ammannii, decreased the NRE of S. breviflora. NRE was significantly negatively correlated with N concentration in senesced leaves, and PRE was significantly negatively correlated with P concentration in senesced leaves. Conclusions: Increasing water indirectly reduces NRE by reducing plant leaf green leaves nitrogen concentration, and decreasing water indirectly reduces PRE by reducing soil moisture. [ABSTRACT FROM AUTHOR]

The ability of regional climate models (RCMs) to accurately simulate the current climate is increasingly important for impact assessments over Southeast Asia (SEA), identified as one of the world's most vulnerable regions to climate change. In this study, we evaluate the performance of a set of regional high‐resolution simulations from the Coordinated Regional Climate Downscaling Experiment‐SEA (CORDEX‐SEA) in simulating rainfall over the region. Simulations of the 1982–2005 seasonal mean climatology of daily precipitation and precipitation distribution over land are compared to observations from different sources (i.e., in situ‐based and satellite‐based). We also evaluate to what extent the precipitation distribution in RCMs is closer to observations than their associated forcing global climate models (GCMs). Observational estimates of precipitation over SEA have large uncertainties, making the model evaluations complicated. Despite these difficulties, our results highlight that RCMs can reproduce some complexities in the spatial distribution of seasonal rainfall but generally have a larger wet bias than GCMs. This is particularly true for the extremes in which RCMs show a large overestimation of rainfall intensity. There are some precipitation quantiles and grid points in which RCMs show limited reductions in biases compared to observations, but there is no consistency across all simulations and RCMs are generally further away from observations than their forcing GCMs. We find that greater intensity in RCMs over CORDEX‐SEA compared to their associated forcing GCMs is firstly associated with the increased supply of moisture from both local and large‐scale sources. Second, a widespread increase in convective precipitation is found across the region in RCMs. Our findings suggest that a model's ability to simulate precipitation over the region relies more on the RCM setup itself (e.g., parameterization scheme), rather than its forcing GCM. This should be considered when assessing the reliability of RCM precipitation simulations for future projections. [ABSTRACT FROM AUTHOR]

Steroid estrogens (SEs) are mainly derived from livestock manure, and composting is the common method of bioresource utilization. In this study, an open-air composting experiment with dairy manure was conducted to observe the degradation and loss of five SEs under the influence of different precipitation intensities and additional mixed fermentation strains. SE determination results for dairy manure after 30 days of composting indicated that the average removal rates of 17α-estradiol (E2α), estrone (E1), 17β-estradiol (E2β), 17α-ethinyl estradiol (EE2), estriol (E3), and estradiol equivalent (EEQ) were 76.67%, 71.07%, 73.88%, 92.02%, 98.77%, and 88.11%, respectively, partly due to SE runoff. The rates of SEs leaching from the open-air composting dairy manure ranged from 0.05% to 4.75% after 10 rounds of 5–60 mm/d simulated rainfall. The total leaching amount of SEs was positively correlated with rainfall, but the leaching concentrations of SEs were just the opposite. As a result of its role as a degradation intermediate of other SEs, E3 was the most prone to run off. By strengthening the action of microorganisms, the total leaching amount of EEQ increased by 5%, E3 increased by five times, and E2β also underwent a transition from a conjugated form to free. However, there were also fewer final SEs remaining in the composted product, as well as the environmental risks of conjugated SEs. These conclusions can provide beneficial suggestions and references for controlling the environmental risks of SEs in the process of composting livestock and poultry manure. [ABSTRACT FROM AUTHOR]

The amount and intensity of precipitation may have important effects on plant growth and ecosystem carbon exchange in semiarid desert steppes; further understanding of how the dryland carbon cycle responds to changes in precipitation and its underlying mechanisms is necessary for an accurate understanding of the global carbon cycle. A field experiment was conducted in a semiarid desert steppe in Ningxia, China, to clarify the response patterns of ecosystem carbon fluxes along five levels of precipitation gradients (Simulating the natural precipitation percentages of 33 % (−33 %, 84 mm), 66 % (−66 %, 167 mm), 100 % (CK, 253 mm), 133 % (+33 %, 336 mm) and 166 % (+66 %, 420 mm) by rain shelters and sprinklers; CK is natural precipitation). The result showed that the trends of net ecosystem CO2 exchange (NEE) and gross ecosystem photosynthesis (GEP) were consistent and those of ecosystem respiration (ER) and Soil respiration (SR) and autotrophic (Ra) and heterotrophic (Rh) components of SR were also consistent. NEE, ER, GEP and SR all reached their highest values in August. Changes in precipitation significantly affected ecosystem carbon fluxes, with NEE, ER and SR decreasing with decreasing precipitation and NEE, ER and GEP increasing with increasing precipitation. Soil respiration was more sensitive to the decreased precipitation treatment. During the growing season, NEE, ER, GEP, and SR were significantly positively correlated with precipitation, soil moisture (SM) and aboveground biomass (AGB). With the increase of precipitation variability, the promotion effect of increasing precipitation on GEP will exceed the promotion effect on ER, causing changes in carbon exchange and carbon sinks. Photosynthesis and respiration appeared tightly coupled, indicating that photosynthetic products regulate above- and belowground carbon cycling in semiarid steppe. Our study highlights the importance of water availability in carbon exchange processes in semiarid desert steppe of northern China. Decreased precipitation can lead to significant changes in SM and AGB, with negative impacts on GEP and SR, resulting in uncertainty in regional carbon sequestration. These findings will help us understand the vulnerability of semiarid steppe ecosystems under the influence of future precipitation changes and aim to provide a scientific reference for ecological management and restoration of semiarid desert steppes.

Soil microbiota plays a fundamental role in nutrient cycles and plant fitness. However, the response of bacterial and fungal communities interacting with plants to an increase in the water regime in natural ecosystems has yet to be extensively studied. To address this matter, we studied the response of rhizospheric and root endophytic microbial communities to simulated intense precipitation in a natural desert environment. We used amplicon sequencing to identify bacterial (16S) and fungal (ITS) communities of Haloxylon salicornicum (Moq) Bunge ex Boiss., a pivotal plant species in natural ecosystems with a high potential for land restauration. Bacterial community composition included mostly Actinobacteriota in roots and Chloroflexi in rhizospheres, whereas fungal communities were mostly represented by Ascomycota. The decomposition of beta diversity revealed a significant share of i) turnover for bacteria between compartments, ii) nestedness for fungi according to compartments, and iii) nestedness for bacteria in both rhizosphere and roots according to watering. Differential abundances analyses between watering conditions identified respectively i) 29 and 37 differentially abundant bacterial families, and ii) 7 and 6 differentially abundant fungal families for rhizosphere and roots. Watering induced a rapid response from little characterized microbiota potentially involved in nutrient recycling, such as rhizobia and dark septate endophytes. These results provided evidence of the fundamental role of rare and intense precipitation in modifying the microbial composition of roots and rhizosphere of one desert plant species. Moreover, little studied taxa potentially crucial to the plant health in desert environments such as dark septate endophytes and Planctomycetota were identified as pioneer taxa colonizing freshly emitted roots. Collectively, our results help to improve the understanding of desert taxa response to water availability, and may guide future research on natural ecosystems restauration. [Display omitted] • Desert ecosystems are subjected to high water stress, limiting plant growth. • Drought increases the abundance of drought-tolerant Actinobacteria and Acidobacteria. • Microbiota of Haloxylon salicornicum roots and rhizosphere is responsive to water. • Symbionts taxa are differentially expressed following watering. • Little studied dark septate endophytes may be important plant symbiont. [ABSTRACT FROM AUTHOR]

Copyright of Acta Prataculturae Sinica is the property of Acta Prataculturae Sinica Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Evidence is accumulating of the disruptive effects of climate change on species interactions. However, little is known about how changes in climate patterns, such as temporal shifts in rainfall events, will affect multitrophic interactions. Here, we investigated the effects of changes in rainfall patterns on the interactions between root herbivores, a plant, and its associated aboveground insects in a semiarid region by experimentally manipulating in the field rainfall intensity and frequency. We found that a shift in rainfall severely constrained biomass acquisition and flowering of the plant Moricandia moricandioides, resulting in fitness reduction. Importantly, enhanced rainfall affected the interactions between below‐ and some aboveground herbivores, disrupting the positive effects of root herbivores on chewing insects. The shifts in precipitation had also plant‐mediated consequences for planthoppers, the dominant sapsuckers in our study system. A combination of mechanisms involving biomass acquisition and plant defenses seemed to be responsible for the different responses of insects and their interactions with the plant. This study provides evidence that altered rainfall patterns due to climate change affect not only trophic groups differentially but also their interactions. [ABSTRACT FROM AUTHOR]

Nanoscale hydroxyapatite (nHA) was synthesized to investigate its potential as a phosphorus (P) ensembled nanofertilizer, using soybean (Glycine max L.) as a model plant. The conventional analogue phosphate (pi) was used for comparison with the synthesized nHA. Varied precipitation intensities (0%, 30%, 60%, and 100%) were simulated by adding selected volumes of the P fertilizers (nHA or pi) via foliar spray and soil amendment. The total amounts of added P were the same across all the treatments. The importance of a wash-off effect was investigated on foliar-treated seedlings by evaluating different watering heights (20, 120, and 240 cm above the seedlings). Fresh weight, pigment content, macro-, and micronutrient contents were measured in soybean tissues across all the treatments after 4 weeks of greenhouse cultivation. The synthesized nHA showed superior effects on plant nutrient content upon high precipitation intensities. For example, at 100% precipitation intensity, there was 32.6% more P and 33.2% more Ca in shoots, 40.6% more P and 45.4% more Ca in roots, and 37.9% more P and 82.3% more Ca in pods, as compared to those with pi treatment, respectively. No impact on soybean biomass was evident upon the application of nHA or pi. Further investigation into customizing nHA to enhance its affinity with crop leaves and to extend retention time on the leaf surface is warranted given that the present study did not show significant positive impacts of nHA on soybean growth under the effects of precipitation. Taken together, our findings increase understanding of the potential application of nHA as a nano-enabled fertilizer in sustainable agriculture.

Background: Changes in rainfall induced by climate change will likely influence the utilization of water resources and affect the nutrient cycle in plants in the water-limited desert steppe. In order to understand the response of nitrogen and phosphorus resorption characteristics of plant leaves to precipitation changes, this study compared the nitrogen (N) resorption efficiency, phosphorus (P) resorption efficiency and influencing factors of plants in a desert steppe through water treatment experiments., Methods: A 4-year field experiment was performed to examine the response and influencing factors of nitrogen (N) and phosphorus resorption efficiency of five dominant plants in Stipa breviflora desert steppe to simulated precipitation change in Inner Mongolia, with four simulated precipitation gradients including reducing water by 50%, natural precipitation, increasing water by 50%, increasing water by 100%., Results: Compared with natural precipitation, increasing water by 100% significantly increased soil moisture, and significantly increased the aboveground biomass of S. breviflora , C. songorica , A. frigida , decreased the N concentrations in green leaves of S. breviflora, Cleistogenes songorica , Artemisia frigida , Kochia prostrata , decreased the N concentrations in senesced leaves of C. songorica, decreased the P concentrations in green leaves of K. prostrata and Convolvulus ammannii , decreased the NRE of S. breviflora . NRE was significantly negatively correlated with N concentration in senesced leaves, and PRE was significantly negatively correlated with P concentration in senesced leaves., Conclusions: Increasing water indirectly reduces NRE by reducing plant leaf green leaves nitrogen concentration, and decreasing water indirectly reduces PRE by reducing soil moisture., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Bai, Wang, Wang, Li, Ren, Wang, Zhang and Han.)

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Precipitation events can induce episodic CO 2 emissions, so called the “Birch Effect”, which could be affected by soil microbial activity in dryland cropping systems. Our objective was to evaluate the effect of precipitation frequencies on soil CO 2 fluxes and the mechanism responsible for the Birch Effect during fallow after winter wheat harvest in the Loess Plateau of China. A simulated precipitation of 240 mm was applied at 5, 10, and 20 days intervals (I5, I10, and I20, respectively) for 60 days and soil CO 2 flux, K 2 SO 4 -extractable C (EOC) and microbial biomass C (MBC) were measured. The CO 2 flux increased immediately following precipitation events, with peak fluxes of 7.9, 8.2, and 7.7 μmol CO 2 m −2 s −1 for I5, I10, and I20, respectively. Cumulative CO 2 flux from days 55–60 was greater for I5 and I10 than I20. The EOC and MBC were not affected by precipitation simulation at the first event, but MBC increased from the first to the last precipitation event, especially for I5 and I10. The CO 2 flux was strongly correlated with EOC at the first event ( r = 0.73, 0.85 and 0.90 for I5, I10 and I20, P < 0.01, respectively), but not correlated with EOC at the last event for I5 and I10 and the correlation decreased from the first to the last event ( r = 0.47, P < 0.01) for I20. In contrast, the correlation coefficient of CO 2 flux with MBC was not significant at first event and increased to 0.81 ( P < 0.01), 0.44 and 0.47 ( P < 0.05) at the last event for I5, I10 and I20, respectively. Higher precipitation frequency at shorter intervals increased CO 2 emissions compared to lower frequency at longer intervals due to enhanced microbial activity as a result of increased substrate availability from accelerated soil aggregate destruction. The dominant mechanism for the “Birch Effect” shifted from “substrate supply” at the first precipitation event to “microbial stress” at the last event, especially for shorter precipitation intervals. [ABSTRACT FROM AUTHOR]

This study investigated the effect of anions on the uptake of heavy metals and aluminum by Brassica rapa L. from non-contaminated, Cd-contaminated, and sewage sludge compost (SSC)-amended sandy soil. Four types of artificial precipitation were applied: deionized water (pH 5.7) as a control, and solutions of HNO3, H2SO4, and HCl prepared to pH 4.5. Precipitation was applied daily during the last 20 d of cultivation. The pH of the Cd-treated soil after harvest was not affected by any precipitation treatment. Shoot concentrations of heavy metals and Al were unaffected by any treatments on non-contaminated soil. In contrast, all acid treatments increased the Cd concentration in shoots grown on Cd-contaminated soil, but only HNO3 precipitation increased it in SSC-amended soil. These results indicate, even without large soil pH change, there is a possibility that the Cd uptake by B. rapa L. depends on anions in precipitation and chemical form of Cd in the soil under conditions of heavy metal enrichment. [ABSTRACT FROM AUTHOR]

Nanoscale hydroxyapatite (nHA) was synthesized to investigate its potential as a phosphorus (P) ensembled nanofertilizer, using soybean (Glycine max L.) as a model plant. The conventional analogue phosphate (pi) was used for comparison with the synthesized nHA. Varied precipitation intensities (0%, 30%, 60%, and 100%) were simulated by adding selected volumes of the P fertilizers (nHA or pi) via foliar spray and soil amendment. The total amounts of added P were the same across all the treatments. The importance of a wash-off effect was investigated on foliar-treated seedlings by evaluating different watering heights (20, 120, and 240 cm above the seedlings). Fresh weight, pigment content, macro-, and micronutrient contents were measured in soybean tissues across all the treatments after 4 weeks of greenhouse cultivation. The synthesized nHA showed superior effects on plant nutrient content upon high precipitation intensities. For example, at 100% precipitation intensity, there was 32.6% more P and 33.2% more Ca in shoots, 40.6% more P and 45.4% more Ca in roots, and 37.9% more P and 82.3% more Ca in pods, as compared to those with pi treatment, respectively. No impact on soybean biomass was evident upon the application of nHA or pi. Further investigation into customizing nHA to enhance its affinity with crop leaves and to extend retention time on the leaf surface is warranted given that the present study did not show significant positive impacts of nHA on soybean growth under the effects of precipitation. Taken together, our findings increase understanding of the potential application of nHA as a nano-enabled fertilizer in sustainable agriculture. [ABSTRACT FROM AUTHOR]