scholarly journals High nitrogen resorption efficiency of forest mosses

2019 ◽  
Vol 125 (4) ◽  
pp. 557-563 ◽  
Author(s):  
Xin Liu ◽  
Zhe Wang ◽  
Xiaoming Li ◽  
Kathrin Rousk ◽  
Weikai Bao
Keyword(s):  
Nutrient Dynamics ◽  
Tracer Experiment ◽  
N Cycling ◽  
Sink Strength ◽  
Resorption Efficiency ◽  
Moss Species ◽  
Nitrogen Resorption ◽  
Temperature And Precipitation ◽  
Biogeochemical Models ◽  
N Resorption

Abstract Background and Aims Nutrient resorption from senescing tissue is a key mechanism for plants to conserve nutrients, and can affect the nutrient dynamics of ecosystems. Yet, our limited knowledge of nitrogen (N) resorption and release from mosses hampers our understanding of the role of mosses as N sources and, thereby, N cycling in moss-dominated ecosystems. The aims of this study were to estimate N resorption efficiency (NRE) of two moss species, identify the pathways of N release from the mosses and to provide a better understanding of N cycling and budgeting strategies of mosses. Methods The dynamics of N allocation along annual moss segments of two dominant moss species (Actinothuidium hookeri and Hylocomium splendens) were assessed in old-growth fir forests using an in situ15N tracer experiment. Key Results The NRE of A. hookeri and H. splendens was 61 and 52 %, respectively. While the mosses lost 23 and 33 % N from live tissues via leaching, 15 and 14 % of N remained in senesced tissues (>3 years old) in A. hookeri and H. splendens, respectively. Conclusions Both mosses resorbed the majority of their tissue N, but a considerable amount of N was lost from live segments. Our results highlight the crucial role mosses play as N sinks in ecosystems, since N retention (resorbed and sequestered in senescent tissue) outweighed N loss via leaching. However, the sink strength depends on temperature and precipitation, which will change in a future climate. The values for NRE, leaching, etc. estimated here can help improve biogeochemical models aiming to complete N budgets for moss-abundant ecosystems.

Nitrogen resorption and protein degradation during leaf senescence in Chenopodium album grown in different light and nitrogen conditions

2007 ◽  
Vol 34 (5) ◽  
pp. 409 ◽  
Author(s):  
Yuko Yasumura ◽  
Kouki Hikosaka ◽  
Tadaki Hirose
Keyword(s):  
Protein Degradation ◽  
Leaf Senescence ◽  
Chenopodium Album ◽  
Growth Conditions ◽  
Sink Strength ◽  
Physiological Factors ◽  
Nitrogen Resorption ◽  
Protein Pool ◽  
N Resorption ◽  
Leaf N

The extent of nitrogen (N) resorption and the degradability of different protein pools were examined in senescing leaves of an annual herb, Chenopodium album L., grown in two light and N conditions. Both N resorption efficiency (REFF; the proportion of green-leaf N resorbed) and proficiency (RPROF; the level to which leaf N content is reduced by resorption) varied among different growth conditions. During leaf senescence, the majority of soluble and membrane proteins was degraded in all growth conditions. Structural proteins were also highly degradable, implying that no particular protein pool constitutes a non-retranslocatable N pool in the leaf. Leaf carbon/N ratio affected the timing and duration of senescing processes, but it did not regulate the extent of protein degradation or N resorption. Sink–source relationships for N in the plant exerted a more direct influence, depressing N resorption when N sink strength was weakened in the low-light and high-N condition. N resorption was, however, not enhanced in high-light and low-N plants with the strongest N sinks, possibly because it reached an upper limit at some point. We conclude that a combination of several physiological factors determines the extent of N resorption in different growth conditions.

scholarly journals Seedling size and nutrient availability in the fall determine nitrogen resorption and storage compound allocation in Quercus variabilis

2021 ◽  
Author(s):  
Jiaxi Wang ◽  
Mercedes Uscola ◽  
Guolei Li
Keyword(s):  
Growth Phase ◽  
Resorption Efficiency ◽  
Shoot Height ◽  
Seedling Size ◽  
Nitrogen Resorption ◽  
Quercus Variabilis ◽  
Nutrient Reserve ◽  
Terminal Buds ◽  
N Resorption ◽  
N Resorption Efficiency

Abstract Aims Soil fertility and resorption of leaf compounds in the fall can influence resource buildup in plants. However, whether intraspecific differences in seedling size can affect nutrient reserve buildup is unknown. This study examined the effects of seedling size and fall fertilization on the uptake and resorption of nitrogen (N), as well as the allocation of non-structural carbohydrates (NSC) and N in cultivated Quercus variabilis Blume. Methods After the formation of terminal buds (T1), seedlings were stratified into small (shoot height < 30 cm) and large seedlings. During the hardening period, seedlings were treated with three different rates of 15N-enriched fertilizer (0, 12, or 24 mg N seedling− 1) and monitored until leaf fall (T2). Results Small seedlings had lower N resorption efficiency and resorbed proportionally less N than large seedlings. Fall fertilization notably improved N and NSC reserves, without reducing N resorption efficiency. Large seedlings allocated proportionally less N to leaves than small seedlings although both sizes seedlings absorbed similar amounts of N from fall fertilization. The priority perennial organ for NSC allocation was roots, while N allocation was dependent on the phenological growth stage of the seedling. Roots were prioritized during the rapid growth phase, while stems were prioritized during the hardening period. Conclusions Under same fertilizer regime during the growth phase, large seedlings tends to have lower N concentration and have higher resorption efficiency compare to small seedlings, fall fertilization can increase N storage in large seedlings and NSC levels in both seedling sizes, without affecting growth.

N resorption efficiency and proficiency in response to winter cold in three evergreen species

2015 ◽  
Vol 394 (1-2) ◽  
pp. 87-98 ◽  
Author(s):  
Patricia González-Zurdo ◽  
Alfonso Escudero ◽  
Sonia Mediavilla
Keyword(s):  
Resorption Efficiency ◽  
Evergreen Species ◽  
Winter Cold ◽  
N Resorption ◽  
N Resorption Efficiency

scholarly journals Effects of Nitrogen Addition and Reproductive Effort on Nutrient Resorption of a Sand-Fixing Shrub

2020 ◽  
Vol 11 ◽  
Author(s):  
Lilong Wang ◽  
Yulin Li ◽  
Yulong Duan ◽  
Jie Lian ◽  
Yongqing Luo ◽  
...  
Keyword(s):  
Reproductive Effort ◽  
Fruit Production ◽  
Nutrient Resorption ◽  
N Recovery ◽  
N Addition ◽  
Resorption Efficiency ◽  
Temporal Separation ◽  
N Resorption ◽  
N Resorption Efficiency ◽  
Leaf N

Caragana microphylla is a sand-fixing leguminous shrub with strong resistance to drought, cold, and low soil fertility. As a result, it plays an essential role in combating desertification in northern China, but little is known about its nutrient budget. Nutrient resorption is a key process in plant nutrient conservation and has marked ecological implications for plant fitness and ecosystem nutrient cycling. We studied the effects of both nitrogen (N) addition and reproductive effort on leaf N resorption of C. microphylla in a temperate semi-arid sandy land in China. The results showed that sprouting of the early leaves from over-wintered buds employs a strategy for slow returns on nutrient investment with smaller specific leaf area (SLA) and higher N resorption efficiency, whereas the late leaves, which sprout from current-year buds, employ a strategy for quick returns on nutrient investment with higher SLA and lower N resorption efficiency. N addition significantly increased the N resorption efficiency from early leaves while exerting no impact on late leaves, suggesting that the increased N recovery from early leaves is done to sustain the high N demands of late leaves. Reproductive effort did not affect the N resorption from early or late leaves due to the temporal separation between fruit production and leaf senescence. Taken together, our results demonstrate that C. microphylla has evolved different investment strategies for leaf N in early and late leaves to conserve nutrients and facilitate its growth in desertified environments.

scholarly journals The C:N:P Stoichiometry of Planted and Natural Larix principis-rupprechtii Stands along Altitudinal Gradients on the Loess Plateau, China

Forests ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 363
Author(s):  
Fujing Bo ◽  
Yunxiang Zhang ◽  
Han Y. H. Chen ◽  
Pingan Wang ◽  
Xuming Ren ◽  
...  
Keyword(s):  
Nutrient Cycling ◽  
Natural Forests ◽  
Resorption Efficiency ◽  
The Loess Plateau ◽  
Planted Forests ◽  
C:N:P Stoichiometry ◽  
Soil C ◽  
Nitrogen Resorption ◽  
N:P Ratios ◽  
Nitrogen Resorption Efficiency

Carbon:nitrogen:phosphorus (C:N:P) stoichiometry plays a critical role in nutrient cycling, biodiversity, and ecosystem functionality. However, our understanding of the responses of C:N:P stoichiometry to elevation and forest management remains elusive. Here we sampled 18 Larix principis-rupprechtii sites along altitudinal gradients (1700-2300 m) on Guandishan Mountain in the Loess Plateau, China. We determined the leaf, litter, and soil C N P contents and C:N:P stoichiometric ratios, as well as nutrient resorption efficiency (NuRE), and diameter at breast height (DBH) increments in both planted and natural stands, and then tested the impacts of elevation and stand origin on these parameters’ management. We found different C:N:P stoichiometry between natural and planted forests. The results revealed that: soil C, N, and N:P ratios, litter C:P and N:P ratios, leaf C:N and N:P ratios increased significantly; however, soil C:N ratios, litter P, leaf N and P, nitrogen resorption efficiency (NRE), and DBH increments decreased significantly with elevation in the planted forests. Soil C,N and N:P ratios, litter C, as well as C:N and C:P ratios increased significantly with elevation in natural forests. The soil N, P and N:P ratios, litter C:P and N:P ratios, leaf C, C:P and N:P ratios, nitrogen resorption efficiency (NRE), phosphorus resorption efficiency (PRE), and DBH increments were, on average, higher in the planted, rather than natural forests. Our results indicated that there was an enhancing P-limitation in both the planted and natural forests, and the plantations were more restricted by P. Moreover, compared to natural forests, plantations converged toward a higher conservative N- and P-use strategy by enhancing resorption efficiencies of internal nutrient cycling and a higher annual growth rate.

scholarly journals The biodiversity - N cycle relationship: a 15N tracer experiment with soil from plant mixtures of varying diversity to model N pool sizes and transformation rates

2020 ◽  
Vol 56 (7) ◽  
pp. 1047-1061 ◽  
Author(s):  
Soni Lama ◽  
Thomas Kuhn ◽  
Moritz F. Lehmann ◽  
Christoph Müller ◽  
Odette Gonzalez ◽  
...  
Keyword(s):  
N Mineralization ◽  
Tracer Experiment ◽  
Soil Samples ◽  
N Cycling ◽  
Organic N ◽  
Autotrophic Nitrification ◽  
Gross N Mineralization ◽  
Jena Experiment ◽  
N Cycle ◽  
The Jena Experiment

Abstract We conducted a 15N tracer experiment in laboratory microcosms with field-fresh soil samples from a biodiversity experiment to evaluate the relationship between grassland biodiversity and N cycling. To embrace the complexity of the N cycle, we determined N exchange between five soil N pools (labile and recalcitrant organic N, dissolved NH4+ and NO3− in soil solution, and exchangeable NH4+) and eight N transformations (gross N mineralization from labile and recalcitrant organic N, NH4+ immobilization into labile and recalcitrant organic N, autotrophic nitrification, heterotrophic nitrification, NO3− immobilization, adsorption of NH4+) expected in aerobic soils with the help of the N-cycle model Ntrace. We used grassland soil of the Jena Experiment, which includes plant mixtures with 1 to 60 species and 1 to 4 functional groups (legumes, grasses, tall herbs, small herbs). The 19 soil samples of one block of the Jena Experiment were labeled with either 15NH4+ or 15NO3- or both. In the presence of legumes, gross N mineralization and autotrophic nitrification increased significantly because of higher soil N concentrations in legume-containing plots and high microbial activity. Similarly, the presence of grasses significantly increased the soil NH4+ pool, gross N mineralization, and NH4+ immobilization, likely because of enhanced microbial biomass and activity by providing large amounts of rhizodeposits through their dense root systems. In our experiment, previously reported plant species richness effects on the N cycle, observed in a larger-scale field experiment within the Jena Experiment, were not seen. However, specific plant functional groups had a significant positive impact on the N cycling in the incubated soil samples.

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