共查询到20条相似文献,搜索用时 15 毫秒
1.
Jordi Sardans Mireia Bartrons Olga Margalef Albert Gargallo‐Garriga Ivan A. Janssens Phillipe Ciais Michael Obersteiner Bjarni D. Sigurdsson Han Y. H. Chen Josep Peñuelas 《Global Change Biology》2017,23(3):1282-1291
Plant invasion is an emerging driver of global change worldwide. We aimed to disentangle its impacts on plant–soil nutrient concentrations. We conducted a meta‐analysis of 215 peer‐reviewed articles and 1233 observations. Invasive plant species had globally higher N and P concentrations in photosynthetic tissues but not in foliar litter, in comparison with their native competitors. Invasive plants were also associated with higher soil C and N stocks and N, P, and K availabilities. The differences in N and P concentrations in photosynthetic tissues and in soil total C and N, soil N, P, and K availabilities between invasive and native species decreased when the environment was richer in nutrient resources. The results thus suggested higher nutrient resorption efficiencies in invasive than in native species in nutrient‐poor environments. There were differences in soil total N concentrations but not in total P concentrations, indicating that the differences associated to invasive plants were related with biological processes, not with geochemical processes. The results suggest that invasiveness is not only a driver of changes in ecosystem species composition but that it is also associated with significant changes in plant–soil elemental composition and stoichiometry. 相似文献
2.
Phytoplankton acclimates to irradiance by regulating the cellular content of light‐harvesting complexes, which are nitrogen (N) rich and phosphorus (P) poor. Irradiance is thus hypothesised to influence the cellular N : P ratio and the N : P defining the threshold between N and P limitation (the ‘optimal’ N : P). We tested this hypothesis by first addressing the response of the optimal N : P to irradiance in a controlled experiment with Chlamydomonas reinhardtii. Then, we did a meta‐analysis of experimental data on optimal and cellular N : P ratios across light gradients to test the generality of an N : P to light response within species. In both the experiment and the meta‐analysis, N : P ratios decreased with irradiance, indicating that factors affecting underwater irradiance, like depth and the composition of the water, may influence the relative N : P requirement. The effect of irradiance did not differ between optimal and cellular N : P ratios, but observations of optimal N : P were on average 2.8 times higher than observations of cellular N : P. 相似文献
3.
María Jesús I. Briones Niall P. McNamara Jan Poskitt Susan E. Crow Nicholas J. Ostle 《Global Change Biology》2014,20(9):2971-2982
Partially decomposed plant and animal remains have been accumulating in organic soils (i.e. >40% C content) for millennia, making them the largest terrestrial carbon store. There is growing concern that, in a warming world, soil biotic processing will accelerate and release greenhouse gases that further exacerbate climate change. However, the magnitude of this response remains uncertain as the constraints are abiotic, biotic and interactive. Here, we examined the influence of resource quality and biological activity on the temperature sensitivity of soil respiration under different soil moisture regimes. Organic soils were sampled from 13 boreal and peatland ecosystems located in the United Kingdom, Ireland, Spain, Finland and Sweden, representing a natural resource quality range of C, N and P. They were incubated at four temperatures (4, 10, 15 and 20 °C) at either 60% or 100% water holding capacity (WHC). Our results showed that chemical and biological properties play an important role in determining soil respiration responses to temperature and moisture changes. High soil C : P and C : N ratios were symptomatic of slow C turnover and long‐term C accumulation. In boreal soils, low bacterial to fungal ratios were related to greater temperature sensitivity of respiration, which was amplified in drier conditions. This contrasted with peatland soils which were dominated by bacterial communities and enchytraeid grazing, resulting in a more rapid C turnover under warmer and wetter conditions. The unexpected acceleration of C mineralization under high moisture contents was possibly linked to the primarily role of fermented organic matter, instead of oxygen, in mediating microbial decomposition. We conclude that to improve C model simulations of soil respiration, a better resolution of the interactions occurring between climate, resource quality and the decomposer community will be required. 相似文献
4.
《Ecohydrology》2017,10(7)
Peatlands of the Western Boreal Plains are under stress from oil and gas development and associated infrastructure such as road construction and removal. An improved understanding of nutrient cycling and atmospheric carbon dioxide (CO2) exchange interactions in peatlands can assist in recommending best management practices to industry to minimize the ecohydrological disturbance footprint of road features. Peat nutrient (nitrogen, N, and phosphorus, P) supply, net mineralization, groundwater concentrations, and peatland‐atmosphere CO2 exchange rates were quantified within a poor fen bisected by a semi‐permanent road located in the Athabasca Oil Sands region of Alberta, Canada, over one growing season. Results demonstrate that the road impeded groundwater movement across the site; however, water table and moisture differences were minimal, likely due to the unusually wet season. No clear impacts of the road on nutrient dynamics were observed, but subtle differences in productivity and respiration resulted in significantly lower net CO2 sequestration (net ecosystem exchange) on the down‐flow side of the road. Differences in vegetation composition between sides of the road were apparent and likely indicate longer‐term moisture differences at the site. Elevated rates of productivity and respiration coincided with a seasonal change in the relative supplies of N and P (increased N : P ratios), suggesting that the relative availability of N versus P may be important to CO2 fluxes in Western Boreal Plains peatlands. Collectively, these findings demonstrate the need to capture interactions between hydrology, ecology and nutrient biogeochemistry when evaluating peatland carbon cycling response to road disturbances across this region. 相似文献
5.
Anthropogenic nitrogen deposition has shifted many ecosystems from nitrogen (N) limitation to phosphorus (P) limitation. Although well documented in plants, no study to date has explored whether N deposition exacerbates P limitation at higher trophic levels, or focused on the effects of induced plant P limitation on trophic interactions. Insect herbivores exhibit strict N : P homeostasis, and should therefore be very sensitive to variations in plant N : P stoichiometry and prone to experiencing deposition‐induced P limitation. In the current study, we investigated the effects of N deposition and P availability on a plant‐herbivorous insect system. Using common milkweed (Asclepias syriaca) and two of its specialist herbivores, the monarch caterpillar (Danaus plexippus) and milkweed aphid (Aphis asclepiadis) as our study system, we found that experimental N deposition caused P limitation in milkweed plants, but not in either insect species. However, the mechanisms for the lack of P limitation were different for each insect species. The body tissues of A. asclepiadis always exhibited higher N : P ratios than that of the host plant, suggesting that the N demand of this species exceeds P demand, even under high N deposition levels. For D. plexippus, P addition increased the production of latex, which is an important defense negatively affecting D. plexippus growth rate. As a result, we illustrate that P limitation of herbivores is not an inevitable consequence of anthropogenic N deposition in terrestrial systems. Rather, species‐specific demands for nutrients and the defensive responses of plants combine to determine the responses of herbivores to P availability under N deposition. 相似文献
6.
1. Stormwater management ponds (SWMPs) are taking the place of natural ponds and wetlands in urban areas. SWMPs have the potential to serve as hotspots for nutrient cycling, yet little is known about how urban catchments affect nutrient chemistry and stoichiometry within these ponds. 2. We sampled 50 SWMPs in Southern Ontario, Canada, to characterise their seston stoichiometry and make comparisons with published lake and pond data and models of seston stoichiometry. We tested (i) whether C : N : P ratios were similar to natural ponds and small lakes, (ii) whether seston stoichiometry was scale dependent and (iii) whether variability in seston chemistry could be explained by landscape and pond characteristics, such as catchment imperviousness and hydrological condition (based on recently received rainfall). 3. Seston C : N and C : P ratios were significantly lower in SWMPs than published ratios for small lakes, likely because of high nitrogen and phosphorus concentrations in SWMPs. Our results also showed no dependency of stoichiometric ratios on pond size. Analyses of ratios versus landscape and pond characteristics revealed significant relationships only when ponds were grouped based on the hydrological condition of the catchments. 4. It is likely that SWMPs function very differently during wet and dry periods. When SWMPs are disconnected from the landscape after a lengthy dry period, internal processes become increasingly important for seston stoichiometry. 相似文献
7.
为揭示根、叶分解残余物对生态系统养分循环相关过程的影响,研究了分解第3年杉木根残余物(凋R)和叶残余物(凋L)中的微生物群落结构(环丙基脂肪酸/前体结构,Cy/pre;单不饱和脂肪酸/饱和脂肪酸,Mono/sat;真菌/细菌,F/B;革兰氏阳性菌/革兰氏阴性菌,G+/G-)、酶活性(β-葡萄糖苷酶,βG;β-N-乙酰氨基葡糖苷酶,NAG;酸性磷酸酶,AP)、化学元素含量及计量比对氮磷添加的响应。结果表明:(1)与凋R相比,凋L中的Cy/pre、F/B、G+/G-低,Mono/sat高。氮磷添加对分解残余物微生物群落结构影响不显著。(2)与凋R相比,凋L中的βG和NAG活性高、βG/AP大。氮磷添加抑制了AP活性,提高了βG/NAG及βG/AP。且氮磷添加对凋R的AP活性抑制作用更强,对凋L的βG/NAG提升幅度更大。(3)分解残余物中的Mono/sat、G+/G、F/B分别与锰含量、磷/钙、氮含量正相关;AP、βG/NAG分别与氮/磷、磷/铁正相关;βG/AP、NAG、βG分别与氮/锰、磷/镁、氮/钙负相关。表明根、叶分解残余物仍可对生态系统养分循环相关过程产生不同影响,考虑分解残余物类型可提高全球变化背景下生态系统养分循环过程预报精度。 相似文献
8.
- Climate change is altering temperatures and precipitation patterns all over the world. Melting glaciers increase surface run‐off, thereby increasing the transport of suspended solids through streams. The increased load of suspended solids affects turbidity, which decreases the availability of photosynthetically active radiation for primary producers.
- We analysed how glacial loading of clays influences the light : nutrient ratio and photosynthetic parameters (measured with a pulse amplitude modulated fluorometer) and the carbon : phosphorus (C : P) elemental ratio of periphytic primary producers. A field study was conducted in two canopy‐free streams that receive water from the glaciers of Mount Tronador (Patagonia, Argentina), one with high glacial load and the other with clear water. In addition, we conducted an in situ colonisation experiment with three different light treatments.
- We observed that periphytic biomass (chlorophyll a and carbon content) in the streams and in the experiment varied directly with turbidity. Moreover, photosynthetic parameters varied similarly because of an increase in the efficiency of electron transfer per open reactive centre in the more turbid stream and a chronic photoinhibition of photosystem II in the clearer stream.
- Periphytic C : P also varied with turbidity as we observed a decrease in C : P with an increase in light in both streams and in the experiment.
- Our main conclusion is that an increase in glacial melting with its associated increase in glacial clay load should protect primary producers against high irradiances (photosynthetic active radiation + ultraviolet radiation) in canopy‐free streams.
9.
Increased atmospheric carbon dioxide (CO2) concentrations and nitrogen (N) deposition induced by human activities have greatly influenced the stoichiometry of N and phosphorus (P). We used model forest ecosystems in open‐top chambers to study the effects of elevated CO2 (ca. 700 μmol mol?1) alone and together with N addition (100 kg N ha?1 yr?1) on N to P (N : P) ratios in leaves, stems and roots of five tree species, including four non‐N2 fixers and one N2 fixer, in subtropical China from 2006 to 2009. Elevated CO2 decreased or had no effects on N : P ratios in plant tissues of tree species. N addition, especially under elevated CO2, lowered N : P ratios in the N2 fixer, and this effect was significant in the stems and the roots. However, only one species of the non‐N2 fixers showed significantly lower N : P ratios under N addition in 2009, and the others were not affected by N addition. The reductions of N : P ratios in response to elevated CO2 and N addition were mainly associated with the increases in P concentrations. Our results imply that elevated CO2 and N addition could facilitate tree species to mitigate P limitation by more strongly influencing P dynamics than N in the subtropical forests. 相似文献
10.
Understanding the reciprocal interactions between the evolved characteristics of species and the environment in which each species is embedded is a major priority for evolutionary ecology. Here we use the perspective of ecological stoichiometry to test the hypothesis that natural selection on body growth rate affects consumer body stoichiometry. As body elemental composition (nitrogen, phosphorus) of consumers influences nutrient cycling and trophic dynamics in food webs, such differences should also affect biogeochemical processes and trophic dynamics. Consistent with the growth rate hypothesis, body growth rate and phosphorus content of individuals of the Daphnia pulex species complex were lower in Wisconsin compared to Alaska, where the brevity of the growing season places a premium on growth rate. Consistent with stoichiometric theory, we also show that, relative to animals sampled in Wisconsin, animals sampled in Alaska were poor recyclers of P and suffered greater declines in growth when fed low‐quality, P‐deficient food. These results highlight the importance of evolutionary context in establishing the reciprocal relationships between single species and ecosystem processes such as trophic dynamics and consumer‐driven nutrient recycling. 相似文献
11.
为了评价不同森林类型的生态化学计量特征的差异, 以吉林长白山温带针阔混交林、广东鼎湖山亚热带常绿阔叶林、云南西双版纳热带季雨林和江西千烟洲亚热带人工针叶林为研究对象, 通过对2007年4月-2008年5月4种典型区域森林植物叶片和凋落物的碳(C)氮(N)磷(P)元素质量比与N、P再吸收率的分析, 探讨了4种森林类型N、P养分限制和N、P养分再吸收的内在联系。结果表明: 1)从森林类型上看, 温带针阔混交林叶片的C : N : P为321 : 13 : 1, 亚热带常绿阔叶林叶片的C : N : P为561 : 22 : 1, 热带季雨林叶片的C : N : P为442 : 19 : 1, 亚热带人工针叶林叶片的C : N : P为728 : 18 : 1; 凋落物的C : N : P也是亚热带人工林最高, 达1 950 : 27 : 1, 温带针阔混交林的最低, 为552 : 14 : 1, 热带季雨林的为723 : 24 : 1, 亚热带常绿阔叶林的为1 305 : 35 : 1, 不同森林类型凋落物的C : N : P的计量大小关系与叶片的结果一致; 2)从植物生活型上看, 常绿针叶林叶片的C : N均显著高于常绿阔叶林及落叶阔叶林; 叶片C : P与森林类型的关系并不十分密切; 常绿阔叶林叶片的N : P最高, 常绿针叶林次之, 落叶阔叶林最低; 3)植物叶片的N : P与月平均气温有显著的负相关关系, 但叶片的C : P基本不受月平均气温影响, 叶片的C、N、P计量比与降水的线性关系不显著; 4)高纬度地区的植物更易受N元素限制, 而低纬度地区植物更易受P元素的限制; 但受N或P限制的植物并不一定具有高的N或P再吸收率。研究结果表明, 不同类型森林的叶片与凋落物的化学计量特征具有一致性, 但是环境因子对不同类型植物化学计量比的影响并不相同。 相似文献
12.
土壤微生物是生态系统重要的组成成分, 尤其是在土壤风化严重, 养分贫瘠的热带和南亚热带森林生态系统中, 微生物在植物养分的获取、碳循环以及土壤的形成等生态过程中的作用尤为重要。该研究基于鼎湖山南亚热带季风常绿阔叶林长期(10年)的野外模拟酸沉降实验平台, 探究了土壤微生物群落结构对土壤酸化的响应。结果表明, 酸沉降处理显著降低土壤pH (即加剧酸化)。土壤酸化对微生物生物量碳(C)含量的影响不大, 但改变了土壤微生物生物量氮(N)和磷(P)的含量, 导致表层土壤(0-10 cm)微生物生物量C:P和N:P显著提高, 表明土壤酸化可能加剧了微生物P限制。土壤酸化还显著改变了土壤微生物群落结构, 导致次表层土壤(10-20 cm)真菌:细菌显著增加。进一步分析表明, 土壤pH和土壤有效P含量是影响土壤微生物群落最为主要的两个因素。 相似文献
13.
The biochemical basis for variations in the critical nitrogen‐to‐phosphorus (N:P) ratio, which defines the transition between N‐ and P‐limitation of growth rate, is currently not well understood. To assess this issue, we cultured the cryptophyte Rhinomonas reticulata NOVARINO in chemostats with inflow nitrate‐to‐phosphate ratios ranging from 5 to 60 mol N·(mol P)?1 at two light intensities. The nitrate‐to‐phosphate ratio marking the transition between N‐ and P‐limitation was independent of light intensity and was between 30 and 45 mol N/mol P. In N‐limited cells, the particulate N:P ratio was stable at around 23 mol N/mol P over a range of inflow nitrate‐to‐phosphate from 5 to 30, whereas in P‐limited cells this ratio was around 90 mol N/mol P at inflow nitrate‐to‐phosphate ratios of 45 and 60. Cell phosphorus decreased with increasing nitrate‐to‐phosphate ratio up to the critical nitrate‐to‐phosphate ratio for each light intensity, above which they remained stable. The C:P of R. reticulata cells increased with increasing inflow nitrate‐to‐phosphate from around the Redfield value (106 mol C/mol P) to around 700. There was a significant effect of light on C:P in the N‐ limited cells, with higher C:P under high light conditions that was not observed in the P‐limited chemostats. Cellular RNA was not influenced by light but was greatly influenced by the type of nutrient limitation. In contrast, chl a, C, N, and protein were not influenced by the nitrate‐to‐phosphate in the inflow medium. Total protein per RNA was independent of light intensity but exhibited a maximum at inflow nitrate‐to‐phosphate of 30. Our results suggest a strong “two‐level” homeostatic mechanism of cellular N and P content in R. reticulata with two distinct states that are determined by the type of nutrient limitation and not by light. 相似文献
14.
15.
Manuel Villar-Argaiz Juan M. Medina-Sánchez Luis Cruz-Pizarro & Presentación Carrillo 《Freshwater Biology》2001,46(8):1017-1034
1. The inter‐ and intra‐annual changes in the biomass, elemental (carbon (C), nitrogen (N) and phosphorus (P)) and taxonomical composition of the phytoplankton in a high mountain lake in Spain were studied during 3 years with different physical (fluctuating hydrological regime) and chemical conditions. The importance of internal and external sources of P to the phytoplankton was estimated as the amount of P supplied via zooplankton recycling (internal) or through ice‐melting and atmospheric deposition (external). 2. Inter‐annual differences in phytoplankton biomass were associated with temperature and total dissolved phosphorus. In 1995, phytoplankton biomass was positively correlated with total dissolved phosphorus. In contrast, the negative relationship between zooplankton and seston biomass (direct predatory effects) and the positive relationship between zooplankton P excretion and phytoplankton biomass in 1997 (indirect P‐recycling effects), reinforces the primary role of zooplankton in regulating the total biomass of phytoplankton but, at the same time, encouraging its growth via P‐recycling. 3. Year‐to‐year variations in seston C : P and N : P ratios exceeded intra‐annual variations. The C : P and N : P ratios were high in 1995, indicating strong P limitation. In contrast, in 1996 and 1997, these ratios were low during ice‐out (C : P < 100 and N : P < 10) and increased markedly as the season progressed. Atmospheric P load to the lake was responsible for the decline in C : P and N : P ratios. 4. Intra‐annual variations in zooplankton stoichiometry were more pronounced than the overall differences between 1995 and 1996. Thus, the zooplankton N : P ratio ranged from 6.9 to 40.1 (mean 21.4) in 1995, and from 10.4 to 42.2 (mean 24.9) in 1996. The zooplankton N : P ratio tended to be low after ice‐out, when the zooplankton community was dominated by copepod nauplii, and high towards mid‐ and late‐season, when these were replaced by copepodites and adults. 5. In 1995, the minimum demands for P of phytoplankton were satisfied by ice‐melting, atmospheric loading and zooplankton recycling over 100%. In order of importance, atmospheric inputs (> 1000%), zooplankton recycling (9–542%), and ice‐melting processes (0.37–5.16%) satisfied the minimum demand for P of phytoplankton during 1996 and 1997. Although the effect of external forces was rather sporadic and unpredictable in comparison with biologically driven recycle processes, both may affect phytoplankton structure and elemental composition. 6. We identified three conceptual models representing the seasonal phosphorus flux among the major compartments of the pelagic zone. While ice‐melting processes dominated the nutrient flow at the thaw, biologically driven processes such as zooplankton recycling became relevant as the season and zooplankton ontogeny progressed. The stochastic nature of P inputs associated with atmospheric events can promote rapid transitional changes between a community limited by internal recycling and one regulated by external load. 7. The elemental composition of the zooplankton explains changes in phytoplankton taxonomic and elemental composition. The elemental negative balance (seston N : P < zooplankton N : P, low N : P recycled) during the thaw, would promote a community dominated by species with a high demand for P (Cryptophyceae). The shift to an elemental positive balance (seston N : P > zooplankton N : P, high N : P recycled) in mid‐season would skew the N : P ratio of the recycled nutrients, favouring dominance by chrysophytes. The return to negative balance, as a consequence of the ontogenetic increase in zooplankton N : P ratio and the external P inputs towards the end of the ice‐free season, could alleviate the limitation of P and account for the appearance of other phytoplankton classes (Chlorophyceae or Dinophyceae). 相似文献
16.
Ziqi Wang Jie Wang Honghui Wu Tian Yang Yixin An Yunlong Zhang Jianlin Bian Ying Li Haiyan Ren Ariuntsetseg Lkhagva Xu Wang Qiang Yu 《Journal of Plant Ecology》2024,17(1):0
氮沉降对生态系统功能和过程具有显著影响。已有研究表明氮添加会影响植物叶片C:N:P化学计量特征。然而,氮添加对植物根系C:N:P化学计量特征影响的研究罕有报道。本论文的主要目的是对比氮添加对草原植物群落地上和地下C:N:P化学计量特征的影响。我们在内蒙古锡林郭勒草原开展了一个7年的氮添加实验,该实验包括6个处理,分别是对照:control; N1: 0.4 mol·m-2 N; N2: 0.8 mol·m-2 N; N3: 1.6 mol·m-2 N; N4: 2.8 mol·m-2 N; N5: 4 mol·m-2 N,每个处理6次重复。我们测量并分析了植物地上、地下生物量和C:N:P化学计量特征。研究结果表明,氮添加会导致植物群落地上部分碳浓度降低,氮浓度和磷浓度升高,C:N和C:P比值降低,N:P升高,而且地上碳、氮、磷库均因施氮而增加。然而,氮添加对0-10,10-30,30-50和50-100 cm 4个土层的地下部分碳、氮、磷浓度、比例、库和化学计量特征没有显著影响。综上所述,氮添加会显著改变植物群落地上部分C:N:P化学计量特征,进而影响草地生态系统的功能和过程,但对地下C:N:P化学计量特征几乎没有影响。 相似文献
17.
1. The light : nutrient hypothesis (LNH) proposes that herbivore growth rates are maximised at intermediate light‐to‐nutrient ratios. A reduction to light intensity (i.e. decreased light‐to‐nutrient ratio) should lead to reduced food availability for herbivores while excessive light intensity in oligotrophic environments (i.e. increased light‐to‐nutrient ratios) should increase the C : N and C : P ratios of producers. However, this hypothesis has not yet been supported by studies on stream ecosystems. 2. We tested the LNH by experimental application of controlled natural gradients in light intensity to oligotrophic laboratory channels that included periphyton and the freshwater snail Gyraulus chinensis. 3. The results in this oligotrophic environment indicate that light regulated the flow of matter between trophic levels and grazer reproduction by controlling C : P ratios of the producers. 相似文献
18.
Two hypotheses have been proposed to explain increases in plant nitrogen (N) and phosphorus (P) concentrations with latitude: (i) geochemical limitation to P availability in the tropics and (ii) temperature driven variation in growth rate, where greater growth rates (requiring greater nutrient levels) are needed to complete growth and reproduction within shorter growing seasons in temperate than tropical climates. These two hypotheses were assessed in one forest type, intertidal mangroves, using fertilized plots at sites between latitudes 36º S and 27º N. The N and P concentrations in mangrove leaf tissue increased with latitude, but there were no trends in N : P ratios. Growth rates of trees, adjusted for average minimum temperature showed a significant increase with latitude supporting the Growth Rate Hypothesis. However, support for the Geochemical Hypothesis was also strong; both photosynthetic P use efficiency and nutrient resorption efficiency decreased with increasing latitude, indicating that P was less limiting to metabolism at the higher latitudes. Our study supports the hypothesis that historically low P availability in the tropics has been an important selective pressure shaping the evolution of plant traits. 相似文献
19.
Jordi Sardans Oriol Grau Han Y. H. Chen Ivan A. Janssens Philippe Ciais Shilong Piao Josep Peñuelas 《Global Change Biology》2017,23(9):3849-3856
Global change impacts on biogeochemical cycles have been widely studied, but our understanding of whether the responses of plant elemental composition to global change drivers differ between above‐ and belowground plant organs remains incomplete. We conducted a meta‐analysis of 201 reports including 1,687 observations of studies that have analyzed simultaneously N and P concentrations changes in leaves and roots in the same plants in response to drought, elevated [CO2], and N and P fertilization around the world, and contrasted the results within those obtained with a general database (838 reports and 14,772 observations) that analyzed the changes in N and P concentrations in leaves and/or roots of plants submitted to the commented global change drivers. At global level, elevated [CO2] decreased N concentrations in leaves and roots and decreased N:P ratio in roots but no in leaves, but was not related to P concentration changes. However, the response differed among vegetation types. In temperate forests, elevated [CO2] was related with lower N concentrations in leaves but not in roots, whereas in crops, the contrary patterns were observed. Elevated [CO2] decreased N concentrations in leaves and roots in tundra plants, whereas not clear relationships were observed in temperate grasslands. However, when elevated [CO2] and N fertilization coincided, leaves had lower N concentrations, whereas root had higher N concentrations suggesting that more nutrients will be allocated to roots to improve uptake of the soil resources not directly provided by the global change drivers. N fertilization and drought increased foliar and root N concentrations while the effects on P concentrations were less clear. The changes in N and P allocation to leaves and root, especially those occurring in opposite direction between them have the capacity to differentially affect above‐ and belowground ecosystem functions, such as litter mineralization and above‐ and belowground food webs. 相似文献