Temporal variation in nutrient concentrations of Pinus sylvestris needles

Temporal variation in nutrient concentrations of Scots pine (Pinus sylvestris L.) needles was studied during a three‐year period in three stands of differing stages of development. Concentrations of N, P and K varied significantly between years; this variation was related to differences in needle dry weight. Concentrations of all measured nutrients (N, P, K, Ca, Mg, Mn, Cu, Zn, Fe, B) and Al varied between seasons; this variation was related to nutrient mobility and the annual physiological cycle. Concentrations of the mobile nutrients N, P and K decreased in spring and early summer during shoot and needle elongation and increased in late summer and autumn during needle senescence and litterfall. Concentrations of Mg, Cu, Zn and B followed somewhat similar patterns. The poorly mobile nutrients Ca, Mn and Fe accumulated gradually in needles during each growing season. Needle nutrient concentrations were stable during the nonactive period.     

冰冻灾害前后矿区废弃地栾树杜英混交林生态系统养分含量的比较

对冰冻灾害前后湖南湘潭锰矿矿区废弃地的栾树、杜英混交林生态系统的地表水、土壤、林木及死地被物的养分含量进行对比研究.结果表明:冰冻灾害后,林地地表水的pH值、电导率、溶解氧、K、Ca、Mg含量明显减少,Zn、Mn、Pb含量显著增加;林内土壤含水量、全P、全K含量显著增加,速效N、速效P、速效K含量明显减少,微量元素Cu、Pb、Co含量增加,Fe、Zn、Mn、Cd、Ni含量减少;林木枝、叶、干中含水量均显著减少,树干中N、P、Ca、Mg、Cu、Zn、Mn、Cd、Ni、Pb、Co含量增加,树枝和树叶中P、K、Mg减少,而Cu、Fe、Zn、Mn、Cd、Ni、Pb、Co含量却增加;林地上的死地被物中K、Mg在各组分(未分解、半分解、已分解)含量降低,Cu、Fe、Mn、Ni、Co含量增加.可为突发性自然干扰对植物生命活动的影响及抗御机理的研究提供基础数据.     

Local basal area affects needle litterfall,nutrient concentration,and nutrient release during decomposition in <Emphasis Type="Italic">Pinus halepensis</Emphasis> Mill. plantations in Spain

Key message

Stand density has a positive effect on C, K and Mg concentration in needle litterfall and a negative one on C, N, Ca, K, Mg, P, S, Zn, and Cu release from needle litter. Consequently, forest management practices such as thinning decrease nutrient concentration in needle litterfall and accelerate nutrient release from decomposing needles in Pinus halepensis plantations in Spain.

Context

Silvicultural practices usually include stand density reduction resulting in changes in litterfall and litter decomposition rates. Little is known about the effect on nutrient concentrations in litterfall and nutrient release during decomposition even when this is the main path of nutrient return to soils.

Aims

The aims of the study are to evaluate the seasonal pattern of nutrient concentration in litterfall, to study how nutrients are released from needle litterfall during decomposition, and to assess whether local basal area of the stand affects nutrient concentration of litterfall and nutrient release during litter decomposition.

Methods

Eight plots were established on each of four stands covering the widest range in local basal area. A littertrap and 15 litterbags were placed on each plot. Periodically, needle litterfall and litter contained in the litterbags were analyzed for C, N, Ca, K, Mg, P, S, Fe, Cu, Mn, and Zn.

Results

Local basal area had a positive effect on C, K, and Mg concentration in needle litterfall and a negative effect on the release of all the nutrients studied but Fe and Mn during the first 2 years of litter decomposition.

Conclusion

Density management of stands has an impact on nutrient cycling, reducing nutrient concentration in needle litterfall, and accelerating nutrient release during decomposition.

     

Deposition of litter and nutrients in leaves and twigs in different plant communities of northeastern Mexico

Studies on litterfall and decomposition provide estimations of decomposition rates of different ecosystems.This is key information to understanding ecosystem dynamics and changes in a scenario of global warming.The objective of this research was to assess litterfall production,the potential deposition of macro and micronutrients through leaf and twig fall as well as macronutrient—use efficiency in three forest ecosystems at different altitudes: a pine forest mixed with deciduous species(S1); a Quercus spp.forest(S2); and,a Tamaulipan thornscrub forest(S3).Total annual litterfall deposition was 594,742 and 533 g m~(-2) for S1,S2 and S3.Leaf litter was higher (68%) than twigs(18%),reproductive structures(8%) or miscellaneous material(6%).Micronutrient leaf deposition was higher for Fe followed by Mn,Zn and Cu.Macronutrient leaf deposition was higher for Ca followed by K,Mg and P.Even though P deposition in leaves and twigs was lower than other macronutrients,its nutrient use efficiency was higher than Ca,Mg or K.Altitude and species composition determine litter and nutrient deposition,with higher values at mid-altitudes(550 m).Altitude is an important factor to consider when analyzing litter production as well as nutrient deposition as shown in this study.Litter production and nutrient deposition are expected to change in a scenario of global warming.     

4个蓝莓品种果实发育期叶片矿质营养动态及其相关性

【目的】了解不同品种蓝莓树体对矿质元素的吸收规律及差异,并为细化蓝莓施肥管理措施提供参考。【方法】以兔眼蓝莓品种‘巨蓝’和‘灿烂’及南高丛蓝莓品种‘薄雾’和‘奥尼尔’为试材,果实发育期间定期采取果实附近的叶片,应用电感耦合等离子发射光谱仪测定并分析了叶片大量矿质元素磷(P)、钾(K)、钙(Ca)、镁(Mg)及微量矿质元素铁(Fe)、锰(Mn)、硼(B)、锌(Zn)、铜(Cu)含量动态及其相关性。【结果】4月22日—7月21日,4个品种叶片K和Cu含量整体呈下降趋势,Ca、Mg、Fe、Mn和B含量整体呈上升趋势,但‘巨蓝’的Ca、Fe、Mn含量在7月21日未出现上升;‘灿烂’‘薄雾’和‘奥尼尔’P含量均在7月21日出现明显回升,而‘巨蓝’P含量持续下降;Zn含量除‘薄雾’变幅较小外,其他3个品种Zn含量呈现"下降—回升"的变化趋势。相关性分析结果表明,K含量与B含量间呈显著负相关,而Ca含量与P、Mg、Fe、Mn、B含量间,P含量与Mg含量间,Mg含量与Fe、Zn、B、Mn含量间,Fe含量与Mn、B含量间,以及Mn含量与B含量间均呈显著正相关。【结论】除‘巨蓝’Mg含量相对不足外,4个品...     

油茶叶不同发育阶段营养元素含量的变化规律

为了解油茶叶（Camellia oleifera）不同发育阶段营养元素含量的变化规律,采集不同发育阶段的油茶叶并测定其营养元素含量,结果表明：油茶叶不同发育阶段均表现出氮最高,其次是钾元素,铜的含量最低;随着油茶叶生长,氮、磷、钾和铜元素含量大致呈先升后降的变化趋势,钙、铁、锰和硼则相反,锌则逐渐降低,而镁差异不大;油茶叶不同发育阶段营养元素总含量为23．39-53．53g／kg,前4个发育阶段油茶叶营养元素总含量差别不大,但到成熟期急剧下降;建议油茶营养调控中要注重各营养元素的含量和比例,特别是后期要注重钙、铁、锰和硼等元素的施用。     

3种桉树幼苗叶片养分变化及其转移特性

我国桉树人工林面积已超过了100万hm2,成为我国南方面积最大的人工林树种之一,并以每年约10万hm2的速度发展.     

用萃取——火焰原子吸收法测定树木叶片矿质元素

用盐酸对马尾松针叶和南方泡桐叶片进行预处理,以火焰原子吸收法对其矿质元素进行测定。结果表明,除铁元素外,钾、钠、钙、镁、锰、锌和铜均有较高的精密度和准确度。而且操作简便、快速,是测定林木叶样矿质元素的较好方法,可以在实际工作中加以推广应用。     

贵州都匀马尾松种子园针叶DRIS营养诊断分析

通过对都匀1．5代无性系种子园20年生马尾松针叶中N、P、K、Ca、Mg、Cu、Zn、Fe、Mn、B等营养元素含量变化的测定和分析,初步筛选出N／P、K／N、Ca／N、Mg／N、N／Cu、zn／N、N／Fe、K／P、Ca／P、P／Mg、P／Cu、P／Zn、Fe／P、K／Ca、K／Mg、K／Cu、K／Zn、Fe／K、Ca／Mg、Ca／Cu、Ca／Zn、Fe／Ca、MgJCu、Zn／Mg、Fe／Mg、Zn／Cu、Fe／Cu、Fe／Zn共28对元素比值为重要参数,对贵州都匀马尾松种子园针叶作DRIS营养诊断分析。结果表明,该地区马尾松针叶内Mn含量过高,平均值为767．01mg／kg,而B含量较低,仅为12．95mg／kg,马尾松的需肥顺序为Cu〉P〉Zn〉Mg〉Ca〉N〉K〉Fe。     

云南引进葡萄柚品种叶片营养分析

对引种于云南省普文县的9个葡萄柚品种的叶片营养进行了分析,结果表明,(1)葡萄柚叶片中P与K、Mn、Zn呈极显著正相关关系;K与Mg、Mn、Zn显著相关;Ca与Mg、Mn、Fe呈显著或极显著相关;Mg与Mn、Fe分别呈显著、极显著负相关;Mn与Zn呈极显著正相关,N与Mn呈显著负相关。(2)叶片中只有氮、铁含量适宜,磷、钾、锌含量过高,钙、镁、锰含量有不同程度的缺乏。     

Nutrient return via litterfall in two contrasting Pinus sylvestris forests in the Pyrenees under different thinning intensities

Thinning influence on litterfall chemical composition (N, P, K, Ca and Mg) was studied for 30 months in two contrasting Pinus sylvestris L. stands in the western Pyrenees mountain range (Northern Spain): Aspurz (625 m.a.s.l, high productivity, Mediterranean climate) and Garde (1335 m.a.s.l, low productivity, continental climate). Two different thinning intensities were carried out by removing 20% and 30% of pre-thinning basal area. In accordance with site quality differences between sites N, K, Ca and Mg total soil returns via litterfall were significantly higher in Aspurz than in Garde. However, P, K, Ca and Mg concentrations were higher in Garde and N higher in Aspurz. Changes in nutrient concentrations over time varied depending on litterfall fractions, showing a variety of patterns; seasonal (N, P, K) or erratic patterns (Ca, Mg) in Aspurz, and seasonal (N, P), biannual (Ca, Mg) or erratic (K) patterns in Garde. In addition to these patterns, differences in nutrient concentrations between years were found in needle litter in Aspurz but not in Garde. Nitrogen returns to forest floor via litterfall were more constant in Aspurz but followed a pulse dynamics in Garde, with the opposite for P, due to important returns from the miscellaneous fraction in the Mediterranean site. Thinning reduced nutrient returns via litterfall in both sites, but significant differences were found only in summer. These results suggest that Aspurz (Mediterranean stand) is more sensitive in the short-term to human intervention than Garde (continental stand) and therefore site-specific forest management plans should be used within more general region-wide plans in order to ensure sustainability of forests.     

Nutrients in litterfall,forest floor and mineral soils in two adjacent forest ecosystems in Greece

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.     

Dynamics of some mineral nutrients and heavy metals in decomposing forest litter

The dynamics of three major mineral nutrients (K, Ca, Mg) and six heavy metals (Fe, Mn, Zn, Cu, Pb and Cd) were studied in decomposing natural, unpolluted litter in two forest types: Scots pine needle litter in a pure Scots pine forest and oak‐hornbeam leaf litter in a mixed oak‐hornbeam stand. Of the mineral nutrients, only K in the oak‐hornbeam system showed a significant decrease in concentration during the course of litter decomposition. For Ca and Mg in both systems and for K in the Scots pine system no clear relation between concentration and accumulated litter‐mass loss was observed. On the other hand, for Fe, Zn, Pb and Cd at both sites, as well as for Mn in the oak‐hornbeam stand and Cu in the Scots pine stand highly significant positive relations were found between heavy metal concentrations and accumulated mass loss. A decrease in concentration was noted only in the case of Mn in the Scots pine system. No clear pattern was found for Cu in the oak‐hornbeam stand. Concentrations of heavy metals in the decomposing litter reached levels at or above those reported to retard decomposition in other studies. At the oak‐hornbeam stand increased also the absolute amounts of Fe, Zn, Pb and Cd.     

灰木莲人工林营养元素分配及其积累特征

对南宁市46年生灰木莲人工林的9种营养元素(N、P、K、Ca、Mg、Fe、Mn、Zn和Cu)的含量、积累量、年净积累量及其分配特征进行了研究。结果表明:灰木莲不同组分的营养元素含量大致为树叶>树皮>树根>树枝>干材。大量元素N、K在树根中的含量最高,P、Mg在树叶中的含量最高,而Ca则在树皮中含量最高;微量元素在各组分中的含量则以Mn最高,Fe、Zn次之,Cu最低。灰木莲人工林营养元素积累总量为1 948.78 kg/hm2,其中乔木层的营养元素积累量为1 715.22 kg/hm2,占林分营养元素积累总量的88.02%;草本层为74.33 kg/hm2,占总积累量的3.81%;灌木层为83.19 kg/hm2,占总积累量的4.26%;凋落物层为76.04 kg/hm2,占总积累量的3.90%。灰木莲人工林营养元素年净积累量为37.32 kg/(hm2·a),各组分营养元素年净积累量排列顺序为干材>树根>树皮>树叶>树枝。     

Nutrient accessions to the forest floor in karri (Eucalyptus diversicolor F. Muell.) forests of varying age

Nutrient accessions to the forest floor in rainfall, throughfall and stemflow from the understorey and tree strata were measured in karri (Eucalyptus diversicolor F. Muell.) forest of south-west Western Australia. These data, for stands aged 2, 6, 9, and 40 years and for mature forest, were compared with annual accessions of nutrients in litterfall.

With increasing age of the stands, the concentration and amounts of Ca, K, Mg, Na and Cl in throughfall increased. The amounts of Mg, Na and Cl in stemflow from the overstorey were also greatest in the older stands. Although concentrations of nutrients in stemflow from the tree stratum were higher than from the understorey, the quantities of nutrients transported to the forest floor in stemflow from the understorey were greater because of its greater volume.

Rainfall is the major source of Na (64–91%) and Cl (51–79%) and it also contributes significantly to Mg (19–50%) accessions. Of the nutrient pathways between canopy and forest floor, litterfall accounts for the largest proportion of N (89–93%), Ca (80–87%) and P (67–79%) recycled in the karri forest. About equal amounts of K are transferred in litterfall, throughfall and stemflow with approximately 80% of stemflow K originating from the understorey strata.     

Nutrient dynamics in singleleaf pinyon (Pinus monophylla Torr & Frem.) needles

Nutrient retranslocation from existing foliage of singleleaf pinyon pine (Pinus monophylla Torr. & Frem.) did not meet the nutrient demands of new needles on the same branch. Singleleaf pinyon pines, with an average age of 177 years, located at an elevation of 2300 m on a ridge in The Sweetwater Range in Nevada, USA retained needles for 18 or more years and increased needle number per branch by 17-18% annually. With age, needles gained weight and accumulated Ca, Mg, Fe, Zn, P, and Mn. The amount of N per needle showed no consistent trend with needle age. Only Cu and K declined in concentrations and amounts with needle age and these differences were not statistically significant. Retranslocation of nutrients at needle abscission could provide only 2 to 13% of the N, P, K, Fe, Cu, and Mg required by new needles. We conclude that nutrient capital in existing foliage constitutes a long-term nutrient reserve for the tree rather than a mobile nutrient pool.     

红锥人工幼林营养特性研究

对不同月份红锥叶片中营养元素含量的变化及其结构进行研究,结果表明,叶片中N、P、K、Ca、Mg、Mn、Fe、Cu、Zn营养元素含量呈季节性变化,普遍地在生长初期（春季）较高,生长旺期（夏季）最低,而秋冬季生长缓慢时由于积累所致而略有回升;叶片中常量元素含量以N、K、P较高,依次排序为：N〉K〉P〉Mg〉Ca,微量元素含量以Mn、Fe为高,依次排序为：Mn〉Fe〉Zn〉Cu,N、P、K、Ca、Mg、Mn、Fe、Zn、Cu比例为：7.40∶1.00∶5.96∶0.30∶0.51∶1.10∶0.16∶0.05∶0.01;根据研究结果及南方山地的土壤特点,红锥人工幼林的施肥时间宜在春季或春夏之交季节,在肥种及配比上,应在施用大量元素N、P、K、Mg、Ca的基础上配施微肥Zn,配比为N∶P∶K∶Ca∶Mg∶Zn=7.40∶1.00∶5.96∶0.30∶0.51∶0.05.     

大花序桉幼苗营养吸收及分配规律研究

对大花序桉幼苗生物量及营养元素进行测定,结果表明,大花序桉苗木平均单株生物量大小排序为茎>根>叶。幼苗主要营养含量和吸收积累规律为K>N>P>Fe>Mn>Zn>B>Ca>Cu>Mg。大量元素N、P、K贮量最高的部位均为茎,根部和叶中含量相近。大花序桉苗期叶片对主要营养元素N、P和K的吸收分配间存在相互促进的关系;Mg与Ca,Cu与P、K,Zn与N、K、Cu、Fe,Fe与N呈现互相促进关系;Mn与N、Fe、K、Cu,B与P、Cu为相互抑制关系。据此,大花序桉苗期以氮、磷、钾肥为主,其中要求养分K₂O>N>P₂O₅,并有针对性地添加铁肥、锌肥和铜肥。     

南岭自然保护区常绿阔叶林优势树种叶片中11种化学元素含量特征

为探讨南岭自然保护区常绿阔叶林优势树种叶片营养特征及重金属含量水平,测定了保护区16个优势树种叶片中N、P、K、Ca、Al、Na、Mg、Mn、Ni、Cu和Pb共11种化学元素的含量,并分析了其在叶片中的变异特征和相关性。结果表明：该地区植物叶片N、P含量均低于我国陆生植物叶片含量的平均值,叶片Ca、K、Mg含量处于陆地植物叶片的正常范围,叶片Mn含量与广东植物叶片含量接近;16个优势树种叶片重金属含量均处于正常范围;南岭自然保护区优势树种受P限制强烈;尽管16个优势树种叶片暂未受到重金属和Al毒危害,但因华南地区酸沉降引发土壤重金属活化的风险仍存在,应加强对该地区森林土壤化学性质和树木叶片化学元素含量的定期监测研究。     

微波消解-ICP-OES法测定麻竹中12种矿质元素含量的实验

利用微波消解对麻竹叶进行前期处理,采用电感耦合等离子体发射光谱(ICP-OES)法测定竹叶中的12种元素含量。结果表明,该测定方法快速、准确、分析精度高;麻竹叶中所含的12种元素从高到低的排序为K、Ca、Mg、P、Mn、Al、Si、Na、Fe、Zn、Cr和Cu,其中,富含人体必需的Fe、Ca、Si等常量元素和Mn、Cu等微量元素,且K、Ca、Mg、P等元素的含量较高。本项实验建立了微波消解-ICP-OES法测定麻竹竹叶中的矿质元素的检测方法,麻竹叶中微量元素含量丰富。