Root parameters of forest trees as sensitive indicators of acidifying pollutants: a review of research of Japanese forest trees     

Yasuhiro Hirano  Takeo Mizoguchi  Ivano Brunner 《Journal of Forest Research》2007,12(2):134-142

The root parameters of forest trees can be indicators of a changing environment. We summarize the results of root studies with regard to the effects of acidifying pollutants, especially soil acidification and aluminum toxicity, on various root parameters of Japanese forest trees under experimentally controlled conditions. All root parameters such as biomass, morphology, nutritional status, and physiology can be regarded as indicators, because, under laboratory conditions, root responses occur prior to the responses in the aboveground parts. However, considering the conditions of forest sites, the nutritional status and physiological changes are better indicators of soil acidification and Al stress than the biomass and morphological response. The currently available data suggest that the most important indicator is the Ca/Al molar ratio in roots of Japanese tree species. In order to predict and detect the initial effects of soil acidification, we postulate that the specific root response to the Ca/Al molar ratio of tree roots should be considered as a parameter for use in long-term forest monitoring sites.  相似文献   

Effects of chronic acid fog exposure with soil acidification or nitrogen loading on nutrient status in Abies firma seedlings     

Koji Yoshida  Shoko Inaba  Chisato Takenaka  Takafumi Tezuka 《Journal of Forest Research》2005,10(2):157-161

To clarify the nutrient status in momi fir (Abies firma Sieb. et Zucc.) seedlings under complex stress conditions of acid fog with soil acidification or nitrogen loading, we exposed seedling shoots to simulated acid fog (pH 3) and simultaneously loaded the soil with acid or excess nitrogen for 17 months. Proton and nitrogen loading reduced K concentration in soil, but these treatments had little effect on the nutrient status of fine roots in momi fir seedlings. Acid fog exposure resulted in reduced concentrations of Mg, Al, and Fe in current-year needles and Mg, Al, Cu, Fe, and Zn in 1-year-old needles. The complex effects of acid fog exposure with proton or nitrogen loading on nutrient status were relatively slight. However, elements such as Al and Cu notably reflect the effects of proton loading. These results show that the nutrient status of trace elements, rather than major elements, in needles of momi fir seedlings is sensitive to exposure to acid fog or proton loading.  相似文献   

Feedlot Acute Interstitial Pneumonia     

《Veterinary Clinics of North America: Food Animal Practice》2015,31(3):381-389

  相似文献   

Quantitative Accuracy of the Simplified Strong Ion Equation to Predict Serum pH in Dogs          下载免费PDF全文

N.J. Cave  S.T. Koo 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2015,29(3):781-785

Background

Electrochemical approach to the assessment of acid‐base states should provide a better mechanistic explanation of the metabolic component than methods that consider only pH and carbon dioxide.

Hypothesis/Objectives

Simplified strong ion equation (SSIE), using published dog‐specific values, would predict the measured serum pH of diseased dogs.

Animals

Ten dogs, hospitalized for various reasons.

Methods

Prospective study of a convenience sample of a consecutive series of dogs admitted to the Massey University Veterinary Teaching Hospital (MUVTH), from which serum biochemistry and blood gas analyses were performed at the same time. Serum pH was calculated (Hcal+) using the SSIE, and published values for the concentration and dissociation constant for the nonvolatile weak acids (A_tot and K _a), and subsequently Hcal+ was compared with the dog''s actual pH (Hmeasured+). To determine the source of discordance between Hcal+ and Hmeasured+, the calculations were repeated using a series of substituted values for A_tot and K _a.

Results

The Hcal+ did not approximate the Hmeasured+ for any dog (P = 0.499, r ² = 0.068), and was consistently more basic. Substituted values A_tot and K _a did not significantly improve the accuracy (r ² = 0.169 to <0.001). Substituting the effective SID (Atot−[HCO3−]) produced a strong association between Hcal+ and Hmeasured+ (r ² = 0.977).

Conclusions and clinical importance

Using the simplified strong ion equation and the published values for A_tot and K _a does not appear to provide a quantitative explanation for the acid‐base status of dogs. Efficacy of substituting the effective SID in the simplified strong ion equation suggests the error lies in calculating the SID.  相似文献   

Dynamics of phosphatase activities in a cork oak litter (Quercus suber L.) following sewage sludge application     

Sylvie Nèble  Virgile Calvert  Jean Le Petit  Stéven Criquet 《Soil biology & biochemistry》2007,39(11):2735-2742

As part of a study of the processes involved in litter biodegradation following sewage sludge (SS) addition, the variations over 14 months of phosphatase activities in a cork oak litter (Quercus suber L.) were investigated. A field experimental design was carried out using the litter-bag method on both a fertilized plot receiving SS applications (twice ) and a control plot. Acid (APH) and alkaline (BPH) phosphatases were measured, along with several biotic and abiotic variables potentially involved in the regulation of these enzymes. These included moisture, temperature, pH, water-extractable inorganic P (P_W), culturable heterotrophic bacteria and fungi. Sludge addition had significant effects on all the variables measured. Indeed, sludge increased significantly BPH activities, available P_W, microbial densities (i.e. bacteria and fungi) and pH in the fertilized plot. In contrast, APH activities decreased significantly following sludge addition. As a consequence, the BPH/APH ratio increased markedly and immediately in the fertilized plot, but only after the 1st amendment. Following the 1st preconditioning SS amendment, the 2nd fertilization had fewer effects on biological variables, because of summer dryness. The different properties examined varied significantly with incubation time, and most were significantly related to the seasonal patterns of litter moisture in this Mediterranean forest ecosystem. Hence, sewage sludge application modified the intensity of microbial responses to environmental factors, but biological patterns regulating P turn-over were maintained.  相似文献   

腐植酸碱性液体肥对香蕉生长的影响及机制     

张立丹  高诚祥  徐柠  王学江  解永军  孙少龙  樊小林 《华南农业大学学报》2022,43(5):12-19

目的 探究腐植酸碱性肥料对香蕉生长的影响及促生机制,为腐植酸碱性肥料的研制与推广应用提供理论依据。方法 采用盆栽试验,研究腐植酸碱性肥料对香蕉生物量、土壤微生物、酶活性、根系活力和土壤氮磷养分含量的影响。结果 与常规复合肥和无腐植酸碱性液体肥料相比,腐植酸碱性肥料有利于促进香蕉生长,明显增加香蕉生物量、根系活力、土壤脲酶活性、酸性磷酸酶活性、土壤矿质氮含量、有效磷含量以及细菌、真菌和放线菌数量。香蕉叶面积增加了50~100 cm²,生物量增加了10%~21%,香蕉根系活力增加了89%~188%,土壤脲酶活性增加了25%~91%,酸性磷酸酶活性增加了2.4~3.5倍。腐植酸碱性液体肥处理的土壤细菌、真菌和放线菌的数量分别是常规肥料的1.6~14.4、1.7~26.7和2.3~3.8倍,分别是无腐植酸碱性肥的3.0~10.6、3.9~56.0和1.2~2.0倍。结论 施用腐植酸碱性液体肥能明显促进香蕉生长,其机制在于：一方面,肥料的碱性改良了土壤酸性环境而有利于土壤微生物多样性;另一方面,肥料的腐植酸增加了土壤的脲酶和酸性磷酸酶活性,改善了土壤的氮、磷营养状况,进而增加土壤肥力。因此,施用腐植酸碱性液体肥料是为香蕉提供养分和提高土壤肥力的有效措施。  相似文献   

一株可降解苹果废弃枝条的生防细菌鉴定     

白燕燕  杜文彪  张彦芳  左存武 《西北农业学报》2022,(8):990-997

筛选对废弃苹果枝条具有降解作用的细菌,为农业废弃物的资源化利用奠定基础。首先利用稀释涂布法从采集的带菌苹果枝段中分离,再通过羧甲基刚果红培养基和复筛培养基挑选出产纤维素酶的菌株,利用发酵培养基验证筛选菌株的纤维素降解能力,进行腐烂病（Valsa mali）的对峙试验并测定其生防潜力,最后通过菌落形态、显微观察和gyrA序列的16S rDNA分析对细菌进行鉴定。从采集的苹果枝条中共分离出3株细菌,其中X-2菌株对苹果枝条具有降解作用,其最适生长pH为8,最适生长温度为30 ℃左右。菌株分泌产生的滤纸酶（FPAase）、β-葡萄糖苷酶和羧甲基纤维素酶（CMCase）活力分别高达（12.78±0.03） U/mL、（8.63±0.64） U/mL和（8.36±0.02） U/mL,枝条纤维素降解率高达12.36%±0.44%,经过16S rDNA序列测定和Blast 同源序列检索,得出该生防菌株X-2为解淀粉芽孢杆菌 (Bacillus amyloliquefaciens)。菌株X-2可以满足废弃苹果枝条的降解需求,其在碱性条件下生长良好,有望应用于碱性地区废弃枝条纤维素的降解。  相似文献   

发育大豆子叶细胞中酸性磷酸酶的亚细胞学定位     

郑易之  高扬 《大豆科学》1996,15(2):114-118,T001

本实验采用电镜细胞化学技术，观察了酸性磷酸酶在发育中大豆子叶细胞内的亚细胞学分布。酸性磷酸酶除分布在细胞核内的部分染色质上，内质网膜上，质体胞质小泡和胞质中，主要积累于蛋白体内。  相似文献   

应用乳酸菌发酵黑枸杞汁的特性研究     

高辰哲  李明昊  姜欢 《现代农业科技》2021,(10)

为了探寻各种乳酸菌在黑枸杞汁中的发酵能力和特性,选取新鲜黑枸杞汁,采用巴氏杀菌法灭菌,接种于不同乳酸菌进行发酵,对发酵过程中乳酸菌菌群成活数、pH值、花青素含量、总酚含量、黄酮含量、抗氧化能力以及感官评测等的变化进行对比。结果表明:各种乳酸菌能在黑枸杞汁中良好生长,活菌数均突破10~8CFU/mL;发酵48 h后,4种乳酸菌发酵的黑枸杞汁的pH值均低于3.5。与未经发酵的黑枸杞汁相比,经保加利亚乳杆菌发酵后的黑枸杞汁中花青素含量与黄酮含量提升最大,其中花青素提升了33.84%、黄酮提升了68.82%;鼠李糖乳杆菌发酵后,黑枸杞汁的总酚含量提升最多,提升了61.25%;保加利亚乳杆菌发酵后,黑枸杞汁对超氧阴离子自由基和羟自由基的清除能力提升最高,超氧阴离子自由基清除率提升了163.50%、羟自由基清除率提升了59.44%;鼠李糖乳杆菌发酵后,黑枸杞汁有着最强的DPPH自由基去除能力,清除率为89%。经乳酸菌发酵后的黑枸杞汁口感上佳,保加利亚乳杆菌的发酵能力要强于其他3种乳酸菌。该研究结果可为黑枸杞汁的益生菌发酵和益生菌果汁产品开发提供参考。  相似文献   

Molasses as C source for heterotrophic bacteria production on solid fish waste     

Oliver Schneider  Vasiliki Sereti  Ep H. Eding  Johan A.J. Verreth 《Aquaculture (Amsterdam, Netherlands)》2006,261(4):1239-1248

The drumfilter effluent from a recirculation aquaculture system (RAS) can be used as substrate for heterotrophic bacteria production. These bacteria can be reused as aquatic feed. In RAS drumfilter effluents are organic carbon deficient for bacteria production. This is due to nitrogen accumulation in the system water. In the present experiment, a bacteria growth reactor (3.5l) was connected to the drumfilter (filter mesh size 60 μm) outlet of a recirculation system. To counteract carbon deficiency, different supplementation levels of molasses (organic carbon) were tested (carbon fluxes of 0.0, 3.2, 5.8, 7.8, 9.7 gC molasses/l/d; C:N ratios: 3.4, 6.4, 9.4, 13.0 and 16.5). The hydraulic retention time in the bacteria reactor was 6 h. For the maximum flux, the VSS and crude protein productions were about 168 gVSS and 95 g crude protein per kg feed. The maximum conversion of nitrate and ortho-phosphate was 24 g NO₃₋N and 4 gP/kg feed. This equals a conversion of 90% of the inorganic nitrogenous waste and 98% of the ortho-phosphate-P. Furthermore the maximum substrate removal rate and the K_s for molasses were determined (1.62 gC/l/h and 0.097 gC/l respectively). The maximum specific removal rate was 0.31 gC/gVSS/h and the related half saturation constant was 0.008 gC/l. The observed growth rate reached a maximum for C fluxes higher than 8 g/l/d. The present integration of heterotrophic bacteria production in RAS represents, therefore, an innovative option to reduce waste discharge by conversion. If the bacteria are reused as feed, system's ecological sustainability increases.  相似文献