共查询到20条相似文献，搜索用时 11 毫秒
1.
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
2.
Nicolas Fanin Nathalie Fromin Bruno Buatois Stephan Httenschwiler 《Ecology letters》2013,16(6):764-772
Stoichiometric homeostasis of heterotrophs is a common, but not always well‐examined premise in ecological stoichiometry. We experimentally evaluated the relationship between substrate (plant litter) and consumer (microorganisms) stoichiometry for a tropical terrestrial decomposer system. Variation in microbial C : P and N : P ratios tracked that of the soluble litter fraction, but not that of bulk leaf litter material. Microbial N and P were not isometrically related, suggesting higher rates of P than N sequestration in microbial biomass. Shifts in microbial stoichiometry were related to changes in microbial community structure. Our results indicate that P in dissolved form is a major driver of terrestrial microbial stoichiometry, similar to aquatic environments. The demonstrated relative plasticity in microbial C : P and N : P and the critical role of P have important implications for theoretical modelling and contribute to a process‐based understanding of stoichiometric relationships and the flow of elements across trophic levels in decomposer systems. 相似文献
3.
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
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.
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
6.
黄土高原中部的丘陵沟壑区位于半湿润、半干旱气候带,生态环境脆弱,水土流失严重,植被恢复是该地区水土保持与生态重建的重要措施。辽东栎天然次生林和刺槐人工林是该地区典型的森林植被类型。以黄土丘陵森林分布区边缘的两种主要森林类型为对象,通过采集林地不同深度土壤样品,对比分析两种林地土壤中碳、氮、磷含量的计量关系及垂直分布特征,旨在探明该区域土壤化学计量特征及主要影响因素。结果表明:(1)在两种林地类型中,土壤有机碳与全碳含量呈正相关关系,两种林地可用同一曲线进行拟合,说明特定土壤类型在同一区域其有机碳和无机碳相对含量基本稳定。(2)土壤有机碳与全氮比值在10左右,在不同土层深度无明显变化;而土壤全碳与全氮比值则随土壤深度的增加而增加,超过1 m以后呈现饱和曲线的变化趋势。(3)土壤氮磷比随土壤深度的增加呈幂次型降低。 相似文献
7.
氮沉降持续增加背景下土壤C∶N∶P化学计量比和pH环境等的改变及其可能的土壤微生物学机制已经成为陆地生态系统与全球变化研究的新生长点和科学研究前沿.以生态化学计量学和土壤微生物生态学为理论基础,综述了氮沉降对森林土壤有机质和凋落物分解的影响及其微生物学机制的基本理论、最新进展、研究热点与难点,旨在促进全球变化背景下陆地生态系统地下生态学的研究.氮沉降持续增加会导致森林生态系统磷循环加速,导致磷限制.氮沉降不但改变森林土壤有机质和凋落物的C∶N∶P化学计量比和降低土壤pH值,而且改变土壤微生物生物量碳氮磷、细菌、真菌和放线菌的组成以及影响碳氮磷分解的关键酶活性.氮沉降对森林土壤有机质和凋落物分解的影响表现为促进、抑制和无影响,其影响的差异可能来源于微生物效应的不同.叶片在凋落前有显著的氮磷养分回收,但是根无明显的养分回收,造成土壤有机质和凋落物的C∶N∶P化学计量比存在明显差异.基于DNA/RNA等分子生物学方法为土壤微生物生态学研究提供了强有力的手段,将促进氮沉降对森林土壤有机质和凋落物化学计量比改变的微生物学机制研究. 相似文献
8.
Aim Interpretations of global‐scale patterns in foliar N and P concentrations and N:P ratios across climatic gradients and biomes often ignore complications imposed by taxonomic and phylogenetic structure in the nutrient concentrations of the constituent taxa. We analysed foliar N and P concentrations and N:P ratios of species from similar climate zones, but with contrasting soil fertility, to determine the relative importance of phylogeny and geographic region in driving foliar nutrient concentrations. Location Mediterranean climate regions. Methods Mean foliar N and P concentrations of 564 species from five mediterranean climate regions were compiled. Regional comparisons of foliar N and P concentrations and N:P ratios were performed using a phylogenetically independent contrasts (PIC) procedure. We also evaluated phylogenetic structuring in these variables, determining for each clade whether (1) the mean trait value and (2) the variance in trait values deviate significantly from chance expectation. Results Foliar N and P concentrations were found to vary between regions, a result confirmed using PIC. Tests of phylogenetic structure identified lineages having unusually high or low N and P concentrations, these being largely consistent amongst two of the regions. There was a general pattern of conservatism in foliar N and P concentrations and N:P ratios with localized instances of overdispersion. Main conclusions Our findings identify soil fertility as a strong environmental filter which has led to the dominance of low‐nutrient adapted lineages in the South African Cape and Western Australia. There is also a pronounced clade‐specific ‘stoichiometric homeostasis’ in foliar N and P concentrations and N:P ratios and this strong phylogenetic conservatism, together with the narrow range of foliar concentrations, is an evolutionary outcome of factors associated with developmental and physiological nutrient requirements specific to each lineage. Our results reinforce the need to include phylogenetic considerations in discussions of the biological stoichiometry of plants if we are to expand our current knowledge of foliar N and P concentrations and N:P patterns from an ecological to a biogeographic scale. 相似文献
9.
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
10.
We examined the effect of nitrogen:phosphorus (N:P) ratios and nutrient concentrations on periphyton when nutrients (N and P) are provided in excess. A gradient of seven N:P ratios ranging from 7.5:1 to 1:7.5 and each at three absolute concentrations, was established using nutrient‐releasing substrata placed in a meso‐oligotrophic lake. Differences in total algal biovolume among nutrient ratios were significant (analysis of covariance [ANCOVA]) when P concentration was entered as the co‐variate. In addition, total algal biovolume was significantly correlated with N concentration but not P. To further evaluate the relationship between nutrient ratios and biovolume, we analyzed (using four 1‐way analysis of variances [ANOVAs]) four subsets of data defined as a series of treatments where one nutrient concentration remained relatively constant as the other changed creating different N:P ratios. Ratios of data subsets ranged from 1:1 to 7.5:1 and 1:1 to 1:7.5 with low and high concentrations of both series. Only diatom biovolume varied with ratio but these differences are most likely related to increased green algal abundance. Species richness and diversity differed among N:P ratios (ANCOVA) when P concentration was used as the co‐variate. Stigeoclonium tenue (Ag.) Gomont, which generally accounted for the increase in green algal abundance, varied with nutrient ratio (ANCOVA) when P was the co‐variate. Based on the ANCOVAs, correlations, and one‐way ANOVAs, periphyton in this system appears to be affected by N concentration but not by N:P treatment ratios under nutrient‐rich conditions. When compared with previous studies, these data also suggest that the response of periphyton to in situ treatments constructed with nutrient‐releasing substrata vary between years. 相似文献
11.
- 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.
12.
We measured concentrations of soil nutrients (0–15 and 30–35 cm depths) before and after the dry season in control and dry-season irrigated plots of mature tropical moist forest on Barro Colorado Island (BCI) in central Panama to determine how soil moisture affects availability of plant nutrients. Dry-season irrigation (January through April in 1986, 1987, and 1988) enhanced gravimetric soil water contents to wet-season levels (ca. 400 g kg–1 but did not cause leaching beyond 0.8 m depth in the soil. Irrigation increased concentrations of exchangeable base cations (Ca2+, Mg2+, K+, Na+), but it had little effect on concentrations of inorganic N (NH4+C, NO3– and S (SO42–). These BCI soils had particularly low concentrations of extractable P especially at the end of the dry season in April, and concentrations increased in response to irrigation and the onset of the rainy season. We also measured the response of soil processes (nitrification and S mineralization) to irrigation and found that they responded positively to increased soil moisture in laboratory incubations, but irrigation had little effect on rates in the field. Other processes (plant uptake, soil organic matter dynamics) must compensate in the field and keep soil nutrient concentrations at relatively low levels. 相似文献
13.
发展生态高效农业实现从“温饱”到“小康”的跨越乾俊礼（中共湖北省老河口市委员会,４４１８００）ＤｅｖｅｌｏｐｉｎｇＨｉｇｈ－ｅｆｆｉｃｉｅｎｔＥｃｏｌｏｇｉｃａｌＡｇｒｉｃｕｌｔｕｒｅａｎｄＲｅａｌｉｚｉｎｇＴｒａｕｓｉｔｉｏｎｆｒｏｍ＂ｐｒｉｌｎａｒｙＳｕｆｆｉｃｉｅｎｃｙ＂ｔｏ＂Ｗｅｌｌ－ｏｆｆ＂￥．ＱｉａｎＪｕｎｌｉ（ＬａｏｈｅｋｏｕＭｕｎｉｃｉｐａｌＣｏｍｍｉｔｔｅｅｏｆＣＰＣ,ＨｕｂｅｉＰｒｏｖｉｎｃｅ４４１８００）．ＣｈｉｎｅｓｅＪｏｕｒｍａｌｏｆＥｃｏｌｏｇｙ,１９９３,１２（２）：８３－８４．Ｄｅｐｅｎｄｅｄｕｐｏｎｔｈｅｄｅｖｅｌｏｐｍｅｎｔｏｆｈｉｇｈ－ｅｆｆｉｃｉｅｎｔｅｃｏｌｏｇｉｃａｌａｇｒｉｃｕｌｔｕｒｅ,ｔｈｅＬａｏｈｅｋｏｕｍｕｎｉｃｉｐａｌｉｔｙｈａｓｒｅａｌｉｚｅｄｔｈｅｔｒａｎｓｉｔｉｏｎｆｒｏｍ＂ｐｒｉｍａｒｙｓｕｆｆｉｃｉｅｎｃｙ＂ｔｏ＂ｗｅｌｌ－ｏｆｆ＂。Ｋｅｙｗｏｒｄｓ：ｈｉｇｈ－ｅｆｆｉｃｉｅｎｔｅｃｏｌｏｇｉｃａｌａｇｒｉｃｕｌｔｕｒｅ,ｐｒｉｍａｒｙｓｕｆｆｉｃｉｅｎｃｙ,ｗｅｌｌ－ｏｆｆ,Ｌａｏｈｅｋｏｕ．党的十一届三中全会以来,在改革开放的推动下,老河 相似文献
14.
生境变化对栓皮栎幼苗营养元素含量的影响 总被引：1，自引：0，他引：1
以栓皮栎在我国天然分布的南界、中部和北界为研究样点,将不同纬度的栓皮栎实生幼苗移栽到同一地点,于生长旺季同时在种源地和移栽地进行取样和测定,探讨生境变化对栓皮栎幼苗生长旺季营养元素含量特征的影响.结果表明:生境变化对栓皮栎幼苗各器官N含量和茎P含量的影响显著,而对各器官K含量和叶片、根P含量影响较小;在种源地,栓皮栎各器官的N含量与纬度间呈极显著的正相关,茎、根的全P含量随纬度升高而降低,叶片N/P的变化不明显;移栽后,北界栓皮栎幼苗各器官的N、P含量显著降低,不同纬度来源对栓皮栎幼苗N、P含量的影响更为明显;各纬度栓皮栎叶片的N/P均有不同程度的升高.不同纬度栓皮栎幼苗不同器官的营养元素含量存在差异,其对生境变化的响应也不相同. 相似文献
15.
Pablo García‐Palacios Fernando T. Maestre Jens Kattge Diana H. Wall 《Ecology letters》2013,16(8):1045-1053
Climate and litter quality have been identified as major drivers of litter decomposition at large spatial scales. However, the role played by soil fauna remains largely unknown, despite its importance for litter fragmentation and microbial activity. We synthesised litterbag studies to quantify the effect sizes of soil fauna on litter decomposition rates at the global and biome scales, and to assess how climate, litter quality and soil fauna interact to determine such rates. Soil fauna consistently enhanced litter decomposition at both global and biome scales (average increment ~ 27%). However, climate and litter quality differently modulated the effects of soil fauna on decomposition rates between biomes, from climate‐driven biomes to those where climate effects were mediated by changes in litter quality. Our results advocate for the inclusion of biome‐specific soil fauna effects on litter decomposition as a mean to reduce the unexplained variation in large‐scale decomposition models. 相似文献
16.
Nitrogen and phosphorus enrichment and balance in forests colonized by cormorants: Implications of the influence of soil adsorption 总被引：3，自引：0，他引：3
Although much concern has been directed at nitrogen (N) cycling in terrestrial ecosystems with bird colonies, little has been clarified on the processes of phosphorus (P) cycling itself, and few comparisons between P and N cycling in bird colonies have been made. On the Isaki Headland and Chikubu Island, which are located on or near the shore of Lake Biwa, Central Japan, a dramatic increase in the population of cormorants has occurred since the 1980s. There has been a concomitant increase in the transport of nutrients from the lake to the waterside ecosystems. We compared the pools and dynamics of N and P in the cormorant-colony forests in order to clarify the effects of differences in soil N and P dynamics on the N–P balance of these colony forests. The total N concentration in the forest floor at excrement-influenced sites was not significantly different from that at sites without such influence, in spite of the heavy load of cormorant-derived N. In contrast to N, forest floor P concentration at the sites with excrement influence was significantly higher compared to sites without such influence, resulting in the lower forest floor N/P ratio at the excrement-influenced sites even after colony abandonment. The site pattern of total N and P concentrations and N/P ratio for mineral soil was similar to that for the forest floor. It seems that the leaky character for N and the accumulative character for P are due to the high mobility of nitrate in soils and the tight absorption of inorganic P to clay minerals, respectively. The site pattern of N/P ratios observed for Chamaecyparis obtusa Sieb. et Zucc. leaves is consistent with that for the forest floor and/or mineral soil, suggesting that the soil geochemical property was reflected in the foliar N/P ratio. The chemistry of throughfall and soil solution was also changed due to deposition of cormorant excrement, and the changes continued for a few years after abandonment of the colony. The quantitative analyses for N and P suggested that the major part of N and P transported by cormorants was not retained in plant matter and the surface soil beneath the colony but instead leached into deeper soil layers. The influence of cormorant excrement on nutrient balance of the whole colony ecosystem is also discussed. 相似文献
17.
18.
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
19.
Annual production of crop residues has reached nearly 4 billion metric tons globally. Retention of this large amount of residues on agricultural land can be beneficial to soil C sequestration. Such potential impacts, however, may be offset if residue retention substantially increases soil emissions of N2O, a potent greenhouse gas and ozone depletion substance. Residue effects on soil N2O emissions have gained considerable attention since early 1990s; yet, it is still a great challenge to predict the magnitude and direction of soil N2O emissions following residue amendment. Here, we used a meta‐analysis to assess residue impacts on soil N2O emissions in relation to soil and residue attributes, i.e., soil pH, soil texture, soil water content, residue C and N input, and residue C : N ratio. Residue effects were negatively associated with C : N ratios, but generally residue amendment could not reduce soil N2O emissions, even for C : N ratios well above ca. 30, the threshold for net N immobilization. Residue effects were also comparable to, if not greater than, those of synthetic N fertilizers. In addition, residue effects on soil N2O emissions were positively related to the amounts of residue C input as well as residue effects on soil CO2 respiration. Furthermore, most significant and stimulatory effects occurred at 60–90% soil water‐filled pore space and soil pH 7.1–7.8. Stimulatory effects were also present for all soil textures except sand or clay content ≤10%. However, inhibitory effects were found for soils with >90% water‐filled pore space. Altogether, our meta‐analysis suggests that crop residues played roles beyond N supply for N2O production. Perhaps, by stimulating microbial respiration, crop residues enhanced oxygen depletion and therefore promoted anaerobic conditions for denitrification and N2O production. Our meta‐analysis highlights the necessity to connect the quantity and quality of crop residues with soil properties for predicting soil N2O emissions. 相似文献
20.
Adrian Ho Thierry K. S. Janssens Rienke Ruijs Sang Yoon Kim Wietse de Boer Aad Termorshuizen Wim H. van der Putten Paul L. E. Bodelier 《Global Change Biology Bioenergy》2017,9(12):1707-1720
With the projected rise in the global human population, agriculture intensification and land‐use conversion to arable fields is anticipated to meet the food and bio‐energy demand to sustain a growing population. Moving towards a circular economy, agricultural intensification results in the increased re‐investment of bio‐based residues in agricultural soils, with consequences for microbially mediated greenhouse gas (GHG) emission, as well as other aspects of soil functioning. To date, systematic studies to address the impact of bio‐based residue amendment on the GHG balance, including the soil microorganisms, and nutrient transformation in agricultural soils are scarce. Here, we assess the global warming potential (GWP) of in situ GHG (i.e., CO2, CH4, and N2O) fluxes after application of six bio‐based residues with broad C : N ratios (5–521) in two agricultural soils (sandy loam and clay; representative of vast production areas in north‐western Europe). We relate the GHG emission to the decomposability of the residues in a litter bag assay and determined the effects of residue input on crop (common wheat) growth after incubation. The shift in the bacterial community composition and abundance was monitored using IonTorrentTM sequencing and qPCR, respectively, by targeting the 16S rRNA gene. The decomposability of the residues, independent of C : N ratio, was proportional to the GWP derived from the GHG emitted. The soils harbored distinct bacterial communities, but responded similarly to the residue amendments, because both soils exhibited the highest mean GWP after addition of the same residues (sewage sludge, aquatic plant material, and compressed beet leaves). Our results question the extent of using the C : N ratio alone to predict residue‐induced response in GHG emission. Taken together, we show that although soil properties strongly affect the bacterial community composition, microbially mediated GHG emission is residue dependent. 相似文献