Carbon allocation of mature spruce upon drought release – results from a whole-tree 13C-labeling study 

2021 ◽  
Author(s):  
Kyohsuke Hikino ◽  
Jasmin Danzberger ◽  
Vincent Riedel ◽  
Benjamin D. Hafner ◽  
Benjamin D. Hesse ◽  
...  
Keyword(s):  
Carbon Allocation ◽  
Belowground Biomass ◽  
Early Summer ◽  
Summer Drought ◽  
Root Tips ◽  
Coarse Roots ◽  
Allocation Pattern ◽  
Recovery Processes ◽  
Source Sink ◽  
Whole Tree

<p>This contribution presents the result of a free-air <sup>13</sup>C labeling experiment on mature Norway spruce (<em>P. abies [L.] KARST.</em>) upon watering after five years of recurrent summer drought in southern Germany, focusing on whole tree allocation processes. Mature spruce trees had been exposed to recurrent summer drought from 2014 to 2018 through complete exclusion of precipitation throughfall from spring to late fall (i.e., March to November).  In early summer 2019, the drought stressed spruce trees were watered to investigate their recovery processes. In parallel with the watering, we conducted a whole-tree <sup>13</sup>C labeling in canopies and traced the signal in various C sinks, i.e. stem phloem and CO<sub>2</sub> efflux, tree rings at different heights, coarse roots, fine root tips, mycorrhiza, root exudates, and soil CO<sub>2</sub> efflux.</p><p>We hypothesize that drought stressed spruce preferentially allocates newly assimilated C to belowground sinks upon drought release. Conversely to our expectations, allocation to belowground C sinks was not stimulated in drought stressed compared to control spruce. Likewise, the relative amount of recently fixed C allocated to aboveground sinks did not differ between treatments. Our findings suggest that the belowground C sinks are not of higher priority for the allocation of newly assimilated C upon watering after long-term drought. The observed allocation pattern is discussed taking total above- and belowground biomass as well as C source/sink relations into account.</p>

scholarly journals C allocation among fine roots, above-, and belowground wood in a deciduous forest and its implication to ecosystem C cycling: a modelling analysis

2008 ◽  
Vol 5 (5) ◽  
pp. 3781-3823 ◽  
Author(s):  
M. Campioli ◽  
H. Verbeeck ◽  
R. Lemeur ◽  
R. Samson
Keyword(s):  
Residence Time ◽  
Fine Roots ◽  
Deciduous Forest ◽  
Net Primary Production ◽  
Severe Drought ◽  
Summer Drought ◽  
Coarse Roots ◽  
Allocation Pattern ◽  
North East ◽  
C Cycling

Abstract. Knowledge about allocation of carbohydrates among tree organs with different life times and decomposition rates is crucial in determining the residence time of carbon (C) in forests and the overall ecosystem C cycling rate. A new model (named CAF) able to simulate C allocation among fine roots, above-, and belowground wood in deciduous forests was developed and integrated into the net ecosystem exchange model FORUG. CAF draws on growth rules and source-sink relationships. Maintenance and growth of the modelled sinks i.e. fine roots, coarse roots, stems, and branches, are controlled by phenology, environment, and by the reserve of non-structural carbohydrates. CAF was parameterized for 2-y and tested against 6-y observations from a beech (Fagus sylvatica L.) stand in North-East France, experiencing summer droughts of different intensities. The model reproduced well (i) the C fluxes allocated annually to assimilation, respiration and biomass production, and (ii) the interannual pattern of wood biomass accumulation. Seasonality of C reserve and wood growth was captured, but some discrepancies were detected at the onset of the growing season. The allocation pattern differed among years, although the overall net primary production decreased only in case of severe drought. During a year with severe drought, the fraction of C allocated to production of fast-decomposing C pools (e.g. fine roots, C reserve) increased by +13% than years without drought, whereas the same fraction increased on average by +18% in case of low to moderate drought. Carbon invested in biomass during a year with summer drought has therefore a shorter residence time in the ecosystem than the C stored during a year without summer drought.

Boreal forest carbon exchange and growth recovery after the summer 2018 drought

2021 ◽  
Author(s):  
Maj-Lena Linderson ◽  
Jutta Holst ◽  
Johannes Edvardsson ◽  
Michal Heliasz ◽  
Leif Klemedtsson ◽  
...  
Keyword(s):  
Carbon Allocation ◽  
Ring Width ◽  
Extended Period ◽  
Forest Growth ◽  
Summer Drought ◽  
Water Fluxes ◽  
Allocation Pattern ◽  
Substantial Impact ◽  
Growth Recovery ◽  
The Impact

<p>In summer 2018, Northern Europe experienced an extreme summer drought in combination with unusually high temperatures, which had a substantial impact on agricultural yields as well as on forest growth conditions in various ways. An earlier study, using ICOS RI (Integrated Carbon Observation Research Infrastructure) stations and other forest ecosystem stations in the Nordic region, shows that the drought dramatically decreased NEP in the southern Scandinavian and Baltic region, almost nullifying the carbon sinks in some of the forests [1]. Such severe conditions during a single year could be expected to influence a forest over following several years. Reduced tree storage of carbohydrates leads to a changed carbon allocation pattern in spring that may affect both the woody growth and pests' resistance. It is thus important to reveal the impact of such climatic events over a more extended period.    </p><p>This study aims at assessing the carry-over effects of the extreme weather conditions on the carbon and water fluxes and the forest growth to the years after the event. The analysis is based on measurement from the stations shown to be significantly affected by the drought through reduced carbon fluxes in 2018: the spruce forests Hyltemossa and Skogaryd and the mixed forests Norunda, Svartberget, Soontaga and Rumperöd. The ecosystem carbon and water fluxes will, together with tree-ring width data, be used to assess the carbon and water exchange and growth recovery in the years after the extreme 2018 drought (2019 and 2020) by comparisons to earlier normal years and extreme events.</p><p>[1] Lindroth, A., et al. (2020): Effects of drought and meteorological forcing on carbon and water fluxes in Nordic forests during the dry summer of 2018 Phil. Trans. R. Soc. B37520190516 https://doi.org/10.1098/rstb.2019.0516</p>

Sink strength of citrus rootstocks under water deficit

2021 ◽  
Author(s):  
Simone F da Silva ◽  
Marcela T Miranda ◽  
Vladimir E Costa ◽  
Eduardo C Machado ◽  
Rafael V Ribeiro
Keyword(s):  
Plant Growth ◽  
Root Growth ◽  
Water Deficit ◽  
Carbon Allocation ◽  
Sink Strength ◽  
Rangpur Lime ◽  
Carbon Supply ◽  
Valencia Orange ◽  
Source Sink ◽  
Orange Trees

Abstract Carbon allocation between source and sink organs determines plant growth and is influenced by environmental conditions. Under water deficit, plant growth is inhibited before photosynthesis and shoot growth tends to be more sensitive than root growth. However, the modulation of source-sink relationship by rootstocks remain unsolved in citrus trees under water deficit. Citrus plants grafted on Rangpur lime are drought tolerant, which may be related to a fine coordination of the source-sink relationship for maintaining root growth. Here, we followed 13C allocation and evaluated physiological responses and growth of Valencia orange trees grafted on three citrus rootstocks (Rangpur lime, Swingle citrumelo and Sunki mandarin) under water deficit. As compared to plants on Swingle and Sunki rootstocks, ones grafted on Rangpur lime showed higher stomatal sensitivity to the initial variation of water availability and less accumulation of non-structural carbohydrates in roots under water deficit. High 13C allocation found in Rangpur lime roots indicates this rootstock has high sink demand associated with high root growth under water deficit. Our data suggest that Rangpur lime rootstock used photoassimilates as sources of energy and carbon skeletons for growing under drought, which is likely related to increases in root respiration. Taken together, our data revealed that carbon supply by leaves and delivery to roots are critical for maintaining root growth and improving drought tolerance, with citrus rootstocks showing differential sink strength under water deficit.

scholarly journals Root-Plate Characteristics of Common Aspen in Hemiboreal Forests of Latvia: A Case Study

Forests ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 32
Author(s):  
Valters Samariks ◽  
Dace Brizga ◽  
Jeļena Rūba ◽  
Andris Seipulis ◽  
Āris Jansons
Keyword(s):  
Root System ◽  
Complex Structure ◽  
Mineral Soil ◽  
Negative Relationship ◽  
Tree Height ◽  
Belowground Biomass ◽  
Rooting Depth ◽  
Economic Losses ◽  
Coarse Roots ◽  
Root Plate

Climate change will cause winds to strengthen and storms to become more frequent in Northern Europe. Windstorms reduce the financial value of forests by bending, breaking, or uprooting trees, and wind-thrown trees cause additional economic losses. The resistance of trees to wind damage depends on tree species, tree- and stand-scale parameters, and root-soil plate characteristics such as root-plate size, weight, and rooting depth. The root-soil plate is a complex structure whose mechanical strength is dependent on root-plate width and depth, as the root system provides root attachment with soil and structural support. In Latvia, the common aspen (Populus tremula L.) root system has been studied to develop a belowground biomass model, because information about root system characteristics in relation to tree wind resistance is scarce. The aim of this study was to assess the root-plate dimensions of common aspen stands on fertile mineral soil (luvisol). Study material was collected in the central region of Latvia, where pure mature (41–60 years old) common aspen stands were randomly selected, and dominant trees within the stand were chosen. In total, ten sample trees from ten stands were uprooted. The diameter at breast height (DBH) and tree height (H) were measured for each sample tree, and their roots were excavated, divided into groups, washed, measured, and weighed. The highest naturally moist biomass values were observed for coarse roots, and fine root biomass was significantly lower compared to other root groups. All root group biomass values had a strong correlation with the tree DBH. The obtained results show that there is a close, negative relationship between the relative distance from the stem and the relative root-plate depth distribution.

Animal production from pasture with and without conservation for winter feeding

1957 ◽  
Vol 1957 ◽  
pp. 17-31
Author(s):  
D. E. Eyles
Keyword(s):  
Early Summer ◽  
Animal Production ◽  
Late Spring ◽  
Summer Drought ◽  
Constant Number ◽  
Seasonal Growth ◽  
Main Obstacle ◽  
Summer Grazing ◽  
Winter Feeding

The uneven seasonal growth of herbage is the main obstacle to the more efficient utilisation of grassland. There is an abundance of growth in late spring and early summer and a scarcity during a summer drought and in winter. Heavy stocking in spring followed by lighter stocking in summer is a suitable management for fattening sheep and cattle because they can be sold fat from June onwards, but a constant number of livestock has to be maintained throughout the year on many farms which carry breeding or growing animals. On these farms grassland, besides giving summer grazing, is expected to provide the bulk of the fodder for over-wintering. It is doubtful whether the results of grazing experiments which evaluate summer grazing only can be applied to these farms.

scholarly journals Summer drought stress: differential effects on cane anatomy and non-structural carbohydrate content in overwintering Cabernet Sauvignon and Syrah vines

2019 ◽  
Vol 13 ◽  
pp. 03007 ◽  
Author(s):  
Rachele Falchi ◽  
Elisa Petrussa ◽  
Marco Zancani ◽  
Valentino Casolo ◽  
Paola Beraldo ◽  
...  
Keyword(s):  
Water Stress ◽  
Drought Stress ◽  
Biochemical Characterization ◽  
Carbon Allocation ◽  
Starch Accumulation ◽  
Cabernet Sauvignon ◽  
Severe Drought ◽  
Summer Drought ◽  
Long Term Effects ◽  
Experimental Conditions

Grapevines store non-structural carbohydrates (NSC) during late summer to sustain plant development at the onset of the following spring’s growth. Starch is the main stored carbohydrate, found in the wood-ray parenchyma of roots and canes. Although the relationship between hydraulic and plant photosynthetic performance is well-recognized, little research has been done on the long-term effects of drought in grapevines adopting different strategies to cope with water stress (i.e. isohydric and anisohydric). We performed our study by exposing two different grape cultivars (Syrah and Cabernet Sauvignon) to a short but severe drought stress, at two stages of the growing season (July and September). No marked differences in the physiological and hydraulic responses of the two varieties were found, probably due to our experimental conditions. However, anatomical and biochemical characterization of overwintering canes pointed out several interesting outcomes. We found a significant and parallel increase of starch and medullar ray number in both cultivars exposed to early water stress. We hypothesize that stressed vines limited their carbon allocation to growth, while shifting it to starch accumulation, with a most evident effect in the period of intense photosynthetic activity. We also speculate that a different aptitude to osmotic adjustment may underlay variation in starch increase and the specific involvement of bark NSC in the two cultivars.

Effect of rates and timing of nitrogen fertilizer on the grain protein content of wheat (Triticum aestivum), grown in two contrasting seasons in South East England

1992 ◽  
Vol 118 (3) ◽  
pp. 265-269 ◽  
Author(s):  
A. A. Sajo ◽  
D. H. Scarisbrick ◽  
A. G. Clewer
Keyword(s):  
Protein Content ◽  
Spring Wheat ◽  
Nitrogen Fertilizer ◽  
Fertilizer Application ◽  
Grain Protein Content ◽  
Early Summer ◽  
Grain Protein ◽  
Summer Drought ◽  
Growing Seasons ◽  
South East England

SUMMARYA field experiment was carried out at the Wye College Farm during 1988 and 1989. The aim was to study the effects of three rates and timings of nitrogen fertilizer application on the grain protein content of spring wheat cv. Axona. Results demonstrated that timing of fertilizer application was more important than the rate of nitrogen used. Grain protein development and final grain protein contents are discussed in relation to the seasonal variations experienced during the 1988 and 1989 growing seasons in South East England. Due to the early February sowing in 1989, grain protein content was not affected by the summer drought. Thus, the advantage of early sowing of spring wheat to reduce the detrimental effect of early summer drought on the grain protein content is emphasised.

Responses of vegetative and reproductive traits to elevated CO2 and nitrogen in Raphanus varieties

1997 ◽  
Vol 75 (4) ◽  
pp. 533-545 ◽  
Author(s):  
Leanne M. Jablonski
Keyword(s):  
Carbon Allocation ◽  
Reproductive Traits ◽  
Test System ◽  
Total Biomass ◽  
Raphanus Raphanistrum ◽  
Reproductive Phase ◽  
Reproductive Response ◽  
Whole Plant ◽  
Vegetative Biomass ◽  
Source Sink

The relationships between the responses to elevated CO2 of the vegetative and reproductive phase were investigated in radish, used as a test system. The hypothesis that an increase in nonfoliar vegetative storage capacity promotes reproductive output was tested. Three cultivars of Raphanus sativus and the wild, Raphanus raphanistrum, differing in root to shoot ratios, were grown under two levels of CO2 and two levels of nitrogen fertilization. Varieties possessed different strategies of carbon storage and showed distinct responses to CO2 at each vegetative harvest time. Vegetative sinks of hypocotyls, petioles, and young blades were enhanced by CO2. Nitrogen promoted vegetative shoot growth, but did not enhance the reproductive response to CO2. By the end of the reproductive phase, varieties did not differ in total biomass. Reproductive response to CO2 may have been limited by the lack of an effect on the timing of flowering. Correlations in CO2 enhancement ratios were examined in 12 traits of each phase. Only vegetative total leaf area correlated with reproductive mass. Foliar starch correlated with decreased abortion. Enhancements in vegetative biomass did not correlate with any reproductive response. Detailed studies of the reproductive phase are needed to understand the whole-plant response to elevated CO2. Key words: elevated CO2, plant reproduction, nitrogen, starch, carbon allocation, source–sink.

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