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1.
Panagiotis Michopoulos Kostas Kaoukis George Karetsos Theodoros Grigoratos Constantini Samara 《林业研究》2020,31(1):291-301
The fluxes of masses and the nutrients Ca,Mg,K,N,P and S were determined in the litterfall of two adjacent forest ecosystems of Hungarian oak(Quercus frainetto L.)and European beech(Fagus sylvatica L.)in a mountainous area of northeastern Greece in 2010–2015.The foliar litterfall for both species reached about 70%of the total litterfall,and was significantly higher from the other two fractions(woody and rest litterfall).The fluxes of masses and nutrients were compared between ecosystems for each fraction separately.Only one significant statistical difference was found,that of K in the woody litterfall.In addition,the stocks of masses and nutrients were calculated in the forest floors and mineral soils of the two ecosystems.Likewise,the stocks of nutrients in the forest floors and mineral soils were compared between ecosystems.In the L horizon of the forest floors,statistical differences,as a result of species effect,were found for the stocks of Ca and N.In the FH horizons,the masses and all the nutrient stocks differed significantly,as the beech plot had much higher quantities of organic matter and nutrients.These higher quantities were probably due to low soil temperatures(microclimate)and high acidity in the beech plot(species effect)that slowed down decomposition.In the mineral soils,the propagation of random error derived from random errors of the individual soil layers was an important factor in the statistical comparisons.Because of the soil acidity in the beech plot,the stocks of exchangeable base cations were significantly higher in the oak plot,whereas the other nutrient stocks did not differ. 相似文献
2.
嫁接对茄子果实中蛋白质、VC、可溶性糖含量及分布的影响 总被引:4,自引:0,他引:4
以托鲁巴姆为砧木、西安绿茄为接穗进行嫁接,研究嫁接对茄子果实中蛋白质、VC、可溶性糖含量及分布的影响。结果表明,嫁接后除可溶性糖含量略低于对照外,蛋白质、VC及果实中的含水量均高于对照。嫁接苗果实中主要营养成分在果实各部位的分布规律基本不变,内果皮中各种养分的含量均高于外果皮,由果实顶部至蒂部各种养分的变化规律不尽相同。随着果实的膨大,嫁接苗果实中主要营养成分的变化规律与对照基本一致。瞪眼期果实中的蛋白质含量较高,进入商品成熟期后,果实中的养分含量基本不变,趋于稳定。 相似文献
3.
4.
四川农村养猪日粮及平衡饲养技术初探 总被引:1,自引:0,他引:1
在四川养猪主产地的不同地理生态区选点,深入农户广泛开展农村养猪常用饲料及日粮调研,采集饲料样品92个,分析测定铁、铜、猛、锌、钴、碘和硒的含量,将四川农村养猪日粮总结划分为:(1)玉米、青料日粮;(2)甘薯、青料日粮;(3)玉米、小麦、青料日粮;(4)玉米、大麦、青料日粮。并对各日粮的营养含量作了概算和评定。在此基础上,提出适合四川农村养猪日粮的添加剂预混料和浓缩料配制建议以及浓缩料主要营养指标推荐值。依此,开展了4种日粮的6批44组347头肉猪的饲养试验。从中优选出一批饲料配方,已在11个地市的40余家厂试产,省内外广大农村养猪中应用,有效地促进了饲料工业和农村养猪生产的发展。研制的甘薯青料日粮及平衡饲养技术,已列专题在省内大面积推广应用。经济效益和社会效益十分显著。 相似文献
5.
心里美萝卜生长动态及养分吸收规律 总被引:16,自引:1,他引:15
对心里美萝卜生长动态及氮、磷、钾、硫吸收规律的研究结果表明:植株鲜重、干重以出苗后61~75天增长最快;肉质根产量在65589kg/hm2时,平均每生产1000kg肉质根,植株需吸收N2.119kg、P2O51.306kg、K2O2.451kg、S0.589kg,比例为1.00∶0.62∶1.16∶0.28;出苗后31~75天是植株吸收养分的主要时期;收获时植株吸收的各种养分主要贮存在肉质根内。 相似文献
6.
Curtis L. VanderSchaaf James A. Moore James L. Kingery 《Forest Ecology and Management》2004,190(2-3):201-218
This study looked at the effects that multi-nutrient fertilization had on understory vegetation nutrient concentrations at four conifer forested locations in the inland Northwest. Multi-nutrient fertilization of conifer stands cannot only enhance the overstory species in the inland Northwest but also the understory vegetation. Determination of nutrient concentration response to fertilization treatments can provide managers the ability to better manipulate their forests for grazing and wildlife habitat. We grouped the understory vegetation into three general life forms: forbs, grasses and grass-likes, and shrubs. Multi-nutrient fertilization had little effect on nitrogen concentration across all life forms. Potassium and sulfur generally increased in concentration. Micronutrients as a whole showed less variability in response to multi-nutrient fertilization. Boron, copper, molybdenum, and zinc generally showed increases in concentrations across all life forms. We were able to conduct analyses on a selected number of understory vegetation species. Individual species showed variability in nutrient concentration response to multi-nutrient fertilization. Wildlife habitat and grazing quality were both increased and decreased following multi-nutrient fertilization. Increases in nutrient concentrations will provide more nutritious vegetation to these animals and vice versa for decreases in concentrations. 相似文献
7.
Karen A. Kainer Lúcia H.O. Wadt Christina L. Staudhammer 《Forest Ecology and Management》2007,250(3):244-255
Brazil nut is widely recognized as the cornerstone of the Amazonian extractive economy. Tight linkages between Brazil nut production, regional income, and intact mature forests have thrust this species into focus as a key component of Amazonian conservation and income generation strategies. Nonetheless, a comprehensive synthesis of factors explaining Brazil nut fruit production variation is lacking. We aimed to address this knowledge gap, asking: (1) What are the rates and annual variation of Bertholletia excelsa fruit production at individual and population levels? (2) What factors explain B. excelsa production variation, focusing on spatial and temporal variables, diameter at breast height (dbh), crown attributes, liana loads, and soil attributes? and (3) Does liana cutting affect fruit production? 相似文献
8.
In May 2006, a high intensity wildfire occurred in Songling forest region in Daxing'an Mountains, China. The concentration changes of eight ions (K^+, Na^+, Ca^2+, Mg^2+, Cl^-, Br^-, NO3^- and SO4^2-) were measured in burned and tmbumed streams after fire from May to Oct., 2006. Results show that the most ions flux were higher in burned stream than that in unburned stream during the sampling period, and the greatest concentrations of most ions transported from burned stream occurred in July. After fire, the most amplitude chemical ion was Ca^2+, whose average concentration was 5.50 mg·L^-1 higher than that in unburned stream, and the total concentration of every chemical ion presents a trend Ca^2+〉SO4^2- 〉Na^+〉Mg^2+〉NO3^- . The average concentrations of Ca^2+, SO4^2- , Na^+'Mg^2+,NO3^- showed an increase trend, but those of K^+, Cl^- , Br had a decreased trend. SO4^2- had the largest loss among these anions, followed by NO3^-. Overall, the increase degree of cation was greater than that of anion after burning. 相似文献
9.
杨树超短轮伐期经营的生产力及材性的研究 总被引:16,自引:0,他引:16
以美洲黑杨2个无性系为供试材料,研究杨树超短轮伐期经营中地上部分生物量生产、分配模式、N、P、K的输出量及材性。结果表明,在3种密度和3种轮伐期的组合中,2个无性系均以造林密度为10000株·ha-1、轮伐期为3年的林分生物生产力最高,I-69杨为10.52t·ha-1·a-1,NL-80351杨约为12.00t·ha-1·a-1;在生物量的分配比率和作为造纸材的经济生物量上也以这种组合模式最为合理,经济生物量最大,I-69杨为7.14t·ha-1·a-1,NL-80351杨为8·47t·ha-1·a-1。养分输出量的多少与林分的生物量生产和分配比率密切相关。轮伐期为3年,密度为10000株·ha-1的林分N、P、K的输出量最高,I-69杨为33.97kg·ha-1·a-1,NL-80351杨为38.50kg·ha-1·a-1,但NL-80351杨每生产1吨经济生物量所输出的N、P、K总量略低于I-69杨。杨树超短轮伐期经营中生产出的木材都可用作中、低档的造纸原料,其中I-69杨的制浆性能优于NL-80351杨。 相似文献
10.
Hirobe Muneto Sabang John Bhatta Balram K. Takeda Hiroshi 《Journal of Forest Research》2004,9(4):341-346
In a lowland tropical rain forest in Sarawak, leaf-litter decomposition and the initial litter chemistry of 15 tree species
were studied. During 13 months of field experiment, weight loss of litter samples was between 44% and 91%, and calculated
decomposition rate constants (k) ranged from 0.38 to 2.36 year−1. The initial litter chemistry also varied widely (coefficients of variation: 19%–74%) and showed low N and P concentrations
and high acid-insoluble residue (AIS) concentration. For nutrient-related litter chemistry, correlations with the decomposition
rate were significant only for P concentration, C/P ratio, and AIS/P ratio (r
s
= 0.59, −0.62, and −0.68, n = 15, P < 0.05, respectively). For organic constituents, correlations were significant for concentrations of AIS and total carbohydrates,
and AIS/acid-soluble carbohydrate ratio (r
s
= −0.81, 0.51, and −0.76, n = 15, P < 0.05, respectively). These results suggested that the relatively slow mean rate of decomposition (k = 1.10) was presumably due to the low litter quality (low P concentration and high AIS concentration), and that P might influence
the decomposition rate; but organic constituents, especially the concentration of AIS, were more important components of initial
litter chemistry than nutrient concentrations. 相似文献