Biomass Allocation Strategies Research Articles

Precipitation-induced biomass enhancement and differential allocation in Inner Mongolia's herbaceous and shrub communities

Changes in precipitation patterns induced by global climate change have profound implications for the structure and function of grassland ecosystems. However, the relationship between plant diversity and ecosystem function across different grassland types, particularly those with varying plant compositions and dominant species, remains inadequately understood. To address this knowledge gap, a five-year experimental manipulation of precipitation was conducted within herbaceous and shrub communities in the desert grasslands of Inner Mongolia. We found that increased precipitation significantly enhances aboveground biomass (AGB), belowground biomass (BGB), and community total biomass (CTB) in both herbaceous and shrub communities. In herbaceous communities, increased precipitation led to a disproportionate increase in both aboveground and belowground biomass, supporting the optimal allocation hypothesis. Structural equation modeling (SEM) further elucidated that precipitation regulates AGB and CTB through species richness and functional traits in herbaceous communities. In shrub communities, precipitation influences AGB, BGB, and CTB by affecting species richness and soil water content. This study highlights the critical role of precipitation in shaping biomass dynamics and allocation strategies within herbaceous and shrub communities in desert steppe of Inner Mongolia. These findings provide essential insights into the potential responses of desert grassland ecosystems to ongoing climate change.

Morphological Traits and Biomass Allocation of Leymus secalinus along Habitat Gradient in a Floodplain Wetland of the Heihe River, China

Plant organ biomass allocation and morphological characteristics are important functional traits. The responses of plant root, stem, and leaf traits to heterogeneous habitats in floodplain wetlands are highly important for understanding the ecological adaptation strategies of riparian plants. However, the patterns of these responses remain unclear. In a floodplain wetland in the middle reaches of the Heihe River, we studied the responses of the root, stem, and leaf morphological traits and biomass allocation of Leymus secalinus to varying habitat conditions. We measured these traits in three sample plots, delineated based on distance from the riverbank: plot I (near the riparian zone, 50–150 m from the riverbank), plot II (middle riparian zone, 200–300 m from the riverbank), and plot III (far riparian zone, 350–450 m from the riverbank). The results showed that in plot I, L. secalinus tended to have slender roots and stems and small leaves, with a biomass allocation strategy that maximized the root–shoot ratio (RSR). In plot II, L. secalinus had thick stems and moderate leaf and root patterns, and the RSR values were between those of plot I and plot III. In plot III, L. secalinus had thin and short stems and large leaves; furthermore, among the root morphological structures, plot III had the shortest Rhizome length (RL) and longest Rhizome diameter (RD), and the RSR was the lowest. Moreover, there was a significant correlation between organ biomass and leaf thickness, stem length, RD, and RL in the three habitats (p < 0.05). By balancing the biomass allocation among organs, wetland plants in floodplains balance changes in root, stem, and leaf morphological characteristics to improve their environmental adaptation.

Belowground plant allocation regulates rice methane emissions from degraded peat soils

Carbon-rich peat soils have been drained and used extensively for agriculture throughout human history, leading to significant losses of their soil carbon. One solution for rewetting degraded peat is wet crop cultivation. Crops such as rice, which can grow in water-saturated conditions, could enable agricultural production to be maintained whilst reducing CO2 and N2O emissions from peat. However, wet rice cultivation can release considerable methane (CH4). Water table and soil management strategies may enhance rice yield and minimize CH4 emissions, but they also influence plant biomass allocation strategies. It remains unclear how water and soil management influences rice allocation strategies and how changing plant allocation and associated traits, particularly belowground, influence CH4-related processes. We examined belowground biomass (BGB), aboveground biomass (AGB), belowground:aboveground ratio (BGB:ABG), and a range of root traits (root length, root diameter, root volume, root area, and specific root length) under different soil and water treatments; and evaluated plant trait linkages to CH4. Rice (Oryza sativa L.) was grown for six months in field mesocosms under high (saturated) or low water table treatments, and in either degraded peat soil or degraded peat covered with mineral soil. We found that BGB and BGB:AGB were lowest in water saturated conditions where mineral soil had been added to the peat, and highest in low-water table peat soils. Furthermore, CH4 and BGB were positively related, with BGB explaining 60% of the variation in CH4 but only under low water table conditions. Our results suggest that a mix of low water table and mineral soil addition could minimize belowground plant allocation in rice, which could further lower CH4 likely because root-derived carbon is a key substrate for methanogenesis. Minimizing root allocation, in conjunction with water and soil management, could be explored as a strategy for lowering CH4 emissions from wet rice cultivation in degraded peatlands.

Regulatory effects of non-growing season precipitation on the community structure, biomass allocation, and water-carbon utilization in a temperate desert steppe

Under the influence of global change, precipitation amounts and extreme precipitation frequency during non-growing seasons in mid-high latitude grasslands have been increasing. However, the ecological effects of non-growing season precipitation in the desert steppe have long been overlooked due to an insufficient understanding of the correlative mechanisms linking non-growing season precipitation to plant growth. Therefore, a 3-year non-growing season precipitation manipulation experiment was conducted to reveal the response of desert steppe plants to non-growing season precipitation changes. Our study indicates that, by influencing water budget and availability, non-growing season precipitation directly or indirectly impacted community structure, plant biomass allocation, and water-carbon utilization intensity. Adaptive strategies of communities and plants included: ① Dominant species enhanced their dominance in the community to adapt to non-growing season precipitation changes. ② Stipa krylovii exhibited different biomass allocation strategies in response to non-growing season precipitation variations. Plants in the precipitation shading plots tended to allocate biomass to the roots, while those in the precipitation increase plots favored aboveground development. ③ Persistent drought during the growing season intensified early insufficient development of plants in the precipitation shading plots. Upon entering the wet period, plants in the precipitation shading plots shifted into a compensatory growth mode with high water-carbon activity intensity, while those in the precipitation increase plots entered a moderate growth mode with relatively low water-carbon activity intensity. Additionally, our study found that the regulatory effects of non-growing season precipitation were more pronounced in the growing seasons with less precipitation in the early to middle stage. Moreover, increased non-growing season precipitation enhanced plant water use efficiency (WUE) and strengthened their resilience to drought conditions. Our study suggests that the ecological role of non-growing season precipitation may be further highlighted in the future climate change pattern. Given the worldwide increase in frequency of extreme precipitation events, particular vigilance should be paid to the underlying long-term adverse effects of severe droughts during the non-growing season. Our findings provide new insights and valuable experimental observational evidence for the climate change impact assessment and response in xerophytic grassland ecosystems.

Contrasting biomass allocations explain adaptations to cold and drought in the world's highest-growing angiosperms.

Understanding biomass allocation among plant organs is crucial for comprehending plant growth optimization, survival and responses to the drivers of global change. Yet, the mechanisms governing mass allocation in vascular plants from extreme elevations exposed to cold and drought stresses remain poorly understood. We analysed organ mass weights and fractions in 258 Himalayan herbaceous species across diverse habitats (wetland, steppe, alpine), growth forms (annual, perennial taprooted, rhizomatous and cushiony) and climatic gradients (3500-6150 m elevation) to explore whether biomass distribution adhered to fixed allometric or optimal partitioning rules, and how variations in size, phylogeny and ecological preferences influence their strategies for resource allocation. Following optimal partitioning theory, Himalayan plants distribute more biomass to key organs vital for acquiring and preserving limited resources necessary for their growth and survival. Allocation strategies are mainly influenced by plant growth forms and habitat conditions, notably temperature, water availability and evaporative demands. Alpine plants invest primarily in below-ground stem bases for storage and regeneration, reducing above-ground stems while increasing leaf mass fraction to maximize carbon assimilation in their short growing season. Conversely, arid steppe plants prioritize deep roots over leaves to secure water and minimize transpiration. Wetland plants allocate resources to above-ground stems and below-ground rhizomes, enabling them to resist competition and grazing in fertile environments. Himalayan plants from extreme elevations optimize their allocation strategies to acquire scarce resources under specific conditions, efficiently investing carbon from supportive to acquisitive and protective functions with increasing cold and drought. Intraspecific variation and shared ancestry have not significantly altered biomass allocation strategies of Himalayan plants. Despite diverse evolutionary histories, plants from similar habitats have developed comparable phenotypic structures to adapt to their specific environments. This study offers new insights into plant adaptations in diverse Himalayan environments and underscores the importance of efficient resource allocation for survival and growth in challenging conditions.

DNA methylation variation and growth in the clonal Duchesnea indica is regulated by both past and present lead environments

ABSTRACT Studies suggest that clonal plants’ ability to select habitats and forage in a heterogeneous environment is influenced by their past environment, with stress legacy potentially playing a crucial role. In this study, we examined parental ramets of Duchesnea indica Focke that were subject to either a control or lead-contaminated environment (past environment), and their newborn offspring were then transplanted into control, homogeneous lead or heterogeneous lead environment (present environment). We analysed how past and present environments affect plant growth and DNA methylation in offspring. The result shown that the DNA methylation loci composition of offspring was affected by the interaction of parental environment and offspring environment, and DNA methylation levels were higher in heterogeneous environments. Moreover, our findings indicate that offspring would thrive in the heterogeneous lead environment if they did not experience lead pollution in the past, their progeny will avoid lead toxicity by reducing underground biomass allocation. However, when the parents experienced lead stress environment, their biomass allocation strategies disappeared, and they prefer to grow in favourable patches to avoid lead-contaminated patches. We concluded that the integration of historical parental exposure to lead-contaminated and current information about their offspring’s environment are impacting plant phenotypes. It is possible that the stress legacy from the parents has been transmitted to their offspring ramets, and the stress legacy is at least partly based on heritable epigenetic variation. The phenotypic variation regulated by the stress legacy affects the growth performance, biomass allocation strategy, and even the behaviour of D. indica.

Native Forbs Grown Under Green Roof Conditions Have Altered Biomass Allocation Strategies and Can be Supported by Commercially-Available Arbuscular Mycorrhizal Fungi

Nature-based solutions like green roofs can help sequester carbon dioxide from the atmosphere, thereby alleviating some of the negative consequences of global warming. Because plants on extensive green roofs typically have short stature and lower biomass than individuals growing on the ground, they are often overlooked in calculations of urban carbon sequestration. However, plants grown on environmentally stressful green roofs may be using alternative physiological strategies, allocating more resources like carbon to below-ground structures than they would be if grown in similar ground-level conditions. Furthermore, overall forb growth and biomass accumulation could be enhanced if plants are grown in the presence of symbiotic fungi that helps obtain water and nutrients. In this experiment, we grew ten native prairie forbs in simulated green roof and ground-level environments to test the hypotheses that plants on green roofs allocate more biomass to below-ground structures in order to overcome stressful environmental conditions and are aided by symbiotic arbuscular mycorrhizal fungi (AMF). We found that commercially available AMF provided significant benefits to some plant species and that plants grown in green roof conditions did in fact allocate more resources below ground compared to their ground-level counterparts. Our results suggest that the ability of green roofs to play a part in sequestering atmospheric carbon via biomass allocation is being largely overlooked and that this contribution to an important ecosystem service should be considered when advocating for increased green roof construction globally.

Climate and breeding determined below-ground biomass allocation strategy in wheat

Farmland covers about 12% of the ice-free terrestrial surface, and crop below-ground biomass allocation plays a pivotal role in the sequestration of atmospheric carbon. Nevertheless, our understanding of the integrated response of crop belowground biomass allocation strategy to concomitant variation in key environmental factors related to water and nutrient availability remains limited. Furthermore, it is imperative to conduct further analysis to elucidate the influence of breeding efforts geared toward improving crop yield on the below-ground biomass allocation strategy. Here we compiled a global wheat root mass fraction (RMF) database with 221 observations from 39 studies to analyze the integrated response of RMF to climate, soil properties and filed managements, and the relationship of RMF and yield. We identified an aridity index (AI) threshold of 0.44 for wheat below-ground biomass allocation strategy, based on the effect of long-term climate on plow-layer soil organic carbon and field water capacity (FWC). The negative effect of nitrogen fertilizer rate on RMF along the AI gradient did not significantly change but the main mechanism shifted from indirect to direct effects. For AI < 0.44, the response of RMF to change of water availability was relatively conservative with the insignificant effects of FWC on RMF. However, RMF was highly sensitive to precipitation distribution during the growth stage because RMF decreased as the ratio of precipitation during the reproductive stage to the growth stage increased. We did not observe a significant correlation between RMF and yield within the main range of RMF so a large amount of intraspecific variation in belowground biomass allocation strategies had not been filtered out by breeding. For AI ≥ 0.44, RMF was highly sensitive to water resource availability as RMF significantly decreased with an increase in FWC. Yield decreased significantly with increasing RMF within the main range of RMF, resulting in highly consistent intraspecific belowground biomass allocation strategies under the pressure of breeding. The results suggested long-term climate condition and breeding played critical filters in wheat below-ground biomass allocation strategy and provided a more accurate prediction of RMF for global carbon cycle models and crop growth models.

Litterfall and element fluxes in secondary successional forests of South Korea

Determining litterfall and corresponding element fluxes is valuable in understanding productivity and biogeochemical cycling in floristically distinct secondary successional zones. Secondary-growth forests form a major portion of the cool-temperate forests of South Korea following decades of severe disturbance and intensive rehabilitation efforts. This study monitored the total and fraction-specific litterfall mass, element flux, and nutrient use efficiency patterns of a secondary-growth broadleaf deciduous forest (hereafter, BDFA) and compared these values in forests with contrasting sub-canopy compositions (BDFB) and with coniferous evergreen forests (CEF). Mean annual total litterfall mass was uniform across stands at a range of 871.5 g m−2 yr−1 to 990.2 g m−2 yr−1. Litterfall mass of seed, bark, and miscellaneous fractions varied per stand (p < 0.05 for seed; p < 0.01 for bark and miscellaneous). A pronounced unimodal litterfall peak was detected for all stands, with total litterfall responding positively to relative humidity but negatively to windspeed and solar radiation. Coniferous evergreen litter contained higher C but lower macronutrients relative to broadleaf deciduous litter. Macronutrient fluxes ranged from 156.2 to 183.9 kg ha−1 yr−1, with broadleaf stands having significantly higher K and Ca rates. Macronutrients were returned in all stands in the order of N > Ca > K > Mg > P, whereas NUE followed a reverse sequence. NUE in CEF was higher than BDFA and BDFB for all macronutrients, reflecting the distinct biomass allocation and nutrient utilization strategies between conifers and broadleaves. In temperate secondary-growth forests, nutrient cycling via litterfall is substantiated primarily by litterfall quantity and secondarily by litter element concentration. Our findings have important implications for elucidating forest litter ecology and improving sustainable management practices in secondary successional forests.

Link between the aboveground and belowground biomass allocation with growing of Tamarix sp. seedlings in the hinterland of Taklimakan Desert, China.

The morphological characteristics and biomass allocation can reflect plant adaptive strategies to the environment. Tamarix sp. is an excellent shrub species used for windbreaks and fixing sand in the desert of northwest China. The successful establishment of Tamarix sp. seedlings and their growth into mature individuals require their adaptation to various environmental conditions, which is the key to naturally regenerating the Tamarix population. To clarify the root morphological characteristics, leaf structural characters, and biomass allocation of Tamarix sp. seedlings in response to drought conditions, we took the Tamarix sp. seedlings at the Daryaboyi oasis in the hinterland of Taklimakan Desert as the object of study, analyzed rooting depth, root dry weight (RDW), specific root length (SRL), root surface area (RA), specific root area (SRA), leaf area (LA), specific leaf area (SLA) and root: shoot ratio (R:S ratio). The gravimetric soil water content varied from 5.80% to 25.84% in this study area. The taproots of Tamarix sp seedlings with small basal stem diameters were shallower and had few lateral root branches and Tamarix sp. seedlings with large basal stem diameters had more obvious taproots and lateral roots. With the growth of Tamarix sp. seedlings, the taproot deepened, and the values ranged from 4.5 cm to 108.0 cm; the SRL, SRA, and SLA decreased, and the ranges of the values were 28.92-478.79 cm·g-1, 1.07-458.50 cm2·g-1, and 24.48-50.7 cm2·g-1; the RDW, RA, and LA increased, the ranges of the values were 0.16-21.34 g, 3.42-328.04 cm2, and 2.41-694.45 cm2; the more biomass was allocated to the aboveground parts, and the mean R: S ratio was 0.76. In better soil water conditions, the root growth rate decreased as Tamarix sp. seedlings grew, and more biomass was allocated to the aboveground. This further showed that stable surface water is highly significant to the biomass allocation strategy of Tamarix sp. seedlings.

Precipitation Dominates the Allocation Strategy of Above- and Belowground Biomass in Plants on Macro Scales.

The allocation of biomass reflects a plant's resource utilization strategy and is significantly influenced by climatic factors. However, it remains unclear how climate factors affect the aboveground and belowground biomass allocation patterns on macro scales. To address this, a study was conducted using aboveground and belowground biomass data for 486 species across 294 sites in China, investigating the effects of climate change on biomass allocation patterns. The results show that the proportion of belowground biomass in the total biomass (BGBP) or root-to-shoot ratio (R/S) in the northwest region of China is significantly higher than that in the southeast region. Significant differences (p < 0.05) were found in BGBP or R/S among different types of plants (trees, shrubs, and herbs plants), with values for herb plants being significantly higher than shrubs and tree species. On macro scales, precipitation and soil nutrient factors (i.e., soil nitrogen and phosphorus content) are positively correlated with BGBP or R/S, while temperature and functional traits are negatively correlated. Climate factors contribute more to driving plant biomass allocation strategies than soil and functional trait factors. Climate factors determine BGBP by changing other functional traits of plants. However, climate factors influence R/S mainly by affecting the availability of soil nutrients. The results quantify the productivity and carbon sequestration capacity of terrestrial ecosystems and provide important theoretical guidance for the management of forests, shrubs, and herbaceous plants.

Nitrogen addition promotes terrestrial plants to allocate more biomass to aboveground organs: A global meta-analysis.

A significant increase in reactive nitrogen (Nr) added to terrestrial ecosystems through agricultural fertilization or atmospheric deposition is considered to be one of the most widespread drivers of global change. Modifying biomass allocation is one primary strategy for maximizing plant growth rate, survival, and adaptability to various biotic and abiotic stresses. However, there is much uncertainty as to whether and how plant biomass allocation strategies change in response to increased nitrogen inputs in terrestrial ecosystems. Here, we synthesized 3,516 paired observations of plant biomass and their components related to nitrogen additions across terrestrial ecosystems worldwide. Our meta-analysis reveals that N addition (ranging from 1.08 to 113.81 g m-2 yr-1 ) increased terrestrial plant biomass by 55.62% on average. Nitrogen addition has increased plant stem mass fraction, shoot mass fraction, and leaf mass fraction by 13.8%, 12.9%, and 13.4%, respectively, but with an associated decrease in plant reproductive mass (including flower and fruit biomass) fraction by 3.4%. We further documented a reduction in plant root-shoot ratio and root mass fraction by 27% (21.8-32.1%) and 14.7% (11.6-17.8%), respectively, in response to N addition. Meta-regression results showed that N addition effects on plant biomass were positively correlated with mean annual temperature, soil available phosphorus, soil total potassium, specific leaf area, and leaf area per plant. Nevertheless, they were negatively correlated with soil total nitrogen, leaf carbon/nitrogen ratio, leaf carbon and nitrogen content per leaf area, as well as the amount and duration of nitrogen addition. In summary, our meta-analysis suggests that N addition may alter terrestrial plant biomass allocation strategies, leading to more biomass being allocated to aboveground organs than belowground organs and growth vs reproductive trade-offs. At the global scale, leaf functional traits may dictate how plant species change their biomass allocation pattern in response to nitrogen addition.

Time to Onset of Flowering, Water Use, and Yield in Wheat

Crop breeding has been successful in increasing crop grain yield (GY; reproductive biomass) largely through reduced vegetative size, increased reproductive effort (RE = reproductive biomass/total biomass) and increased water-use efficiency (WUE) in grain production. Flowering time is an important life history trait that signifies the switch from vegetative to reproductive growth. The relationship between GY and time from sowing to flowering (Tsf) is unclear. We fit the relationships between GY and RE vs. Tsf to the logistic model using data from 18 spring wheat genotypes grown under simulated rainfed conditions. Tsf accounted for water use before and after flowering, root length density, total leaf area, and the time from flowering to harvest. Early flowering meant decreased water use before flowering and increased water use afterward. Soil water remaining at harvest was positively correlated with yield. Early flowering genotypes have a higher WUE of grain production, but there was no significant difference in the WUE of total biomass production. The relationship between grain yield and Tsf is described as a unimodal curve, as is the relationship between RE and Tsf. Higher yields and a higher RE have been achieved through earlier flowering, and both RE and Tsf reached their optimal values for maximizing GY. Crop breeding is unlikely to achieve further increases in GY through this route in the future. The results suggest that breeding does not improve biomass’s water-use efficiency, but causes changes in biomass allocation strategy, and this could be a new direction for genetically improving grain yield.

Low water supply differentially affects the growth, yield and mineral profile of kabuli and desi chickpeas (Cicer arietinum)

AbstractThe climatic events predicted to increase in intensity and frequency in the near future, including drought, may influence the quality and productivity of several important crops for human nutrition, such as legumes. Herein, two chickpea genotypes (Cicer arietinum) were analysed for their resilience to low water supply: a commercial white chickpea (kabuli) and a traditional black chickpea (desi) with marginal production in occidental countries. Plants were grown under four levels of water supplies (90%, 75%, 50% and 25% of field capacity) and biometric variables (root, shoot, pods and seeds), proxies of plant fitness (water content and oxidative stress) and the seed nutritional profile (protein and mineral concentrations) were analysed at plant maturity. The results show that the water content in shoots and roots decreased with the decrease in water supplies, with kabuli plants generally having higher water content in shoots and desi in roots. The shoot length was significantly higher in kabuli compared to desi, while the root length increased up to 11% in both species with the decrease in water supplies. The root‐to‐shoot ratio was higher in kabuli and increased with the decrease in the water supply, being negatively correlated with the number of pods and seeds per plant. Lipid peroxidation also increased with the decrease in the water supply, having slight positive correlations with plant growth parameters while being negatively correlated with plant productivity. No significant effects of plant genotype and water supply were observed on seed K, Ca and protein, but desi was able to sustain higher P, Mg, Zn, Fe, Mn and B concentrations than kabuli, including at lower water supplies. The results suggest that water stress negatively impacts plant growth and productivity and that the two chickpea genotypes have distinct biomass and water allocation strategies to cope with low water supply. These findings may be useful in strategies for improving the productivity and nutritional profile of chickpea crops under water‐limited conditions.

Climate vs. nutrient control: A global analysis of driving environmental factors of wetland plant biomass allocation strategy

Wetland plant biomass and its allocation are sensitive to environmental changes, and they make up a significant part of the carbon pool in wetlands. Here, we collected global data on wetland plant biomass from 1980 to 2021. Based on an analysis of 1134 observations from 182 published papers on wetland ecosystems, we generated spatially explicit global maps of belowground biomass (BGB) to aboveground biomass (AGB) ratio of wetland plants. Our study found that AGB is higher in tropical mangrove regions while BGB is higher in cold regions at high latitudes. AGB did not show a significant response to any individual environmental factors (p > 0.05). In the contrast, plant BGB is influenced by total phosphorus (p < 0.05) but not total nitrogen, and extreme temperatures are the main driver of plant BGB (p < 0.05). Compared to climate factors, soil nutrients were the main factor affecting plant biomass allocation in different wetland types. The relationships between the wetland plant biomass and their environmental conditions are discussed, which provided a basis for further understanding the conservation of wetland plants under environmental change.

Plant community traits and functions mediate the biomass trade-off of alpine grasslands along precipitation gradients on the Tibetan Plateau

AbstractA better understanding the mechanisms driving plant biomass allocation in different ecosystems is an important theoretical basis for illustrating the adaptive strategies of plants. To date, the effects of habitat conditions on plant biomass allocation have been widely studied. However, it is less known how plant community traits and functions (PCTF) affect biomass allocation, particularly in alpine grassland ecosystems. In this study, community-weighted means (CWM) were calculated at the community level using five leaf functional traits, and the relationships between PCTF and biomass trade-offs were explored using correlation analysis, variation partitioning analysis and structural equation modeling. We found that the trade-off values were greater than zero in both alpine meadow (AM) and alpine steppe (AS) across the Tibetan Plateau, with different values of 0.203 and 0.088 for AM and AS, respectively. Moreover, the critical factors determining biomass allocation in AS were species richness (SR; scored at 0.69) and leaf dry matter content of CWM (CWMLDMC, scored at 0.42), while in AM, the key factors were leaf dry matter content (CWMLDMC, scored at 0.48) and leaf carbon content of CWM (CWMLC, scored at −0.45). In particular, both CWMLDMC and SR in AS, as well as CWMLDMC and CWMLC in AM were primarily regulated by precipitation. In summary, precipitation tends to drive biomass allocation in alpine grasslands through its effects on PCTF, hence highlighting the importance of PCTF in regulating plant biomass allocation strategies along precipitation gradients.

Effects of Drought Stress and Ca Supply on the Biomass Allocation Strategies of Poplar and Mulberry

In order to investigate the effect of Ca on the biomass allocation strategies of tree species with different growth rates under drought conditions, we treated poplar (Populus canadensis cv) cuttings and mulberry (Morus alba) seedlings with two soil moisture levels (40 ± 5% and 80 ± 5% maximum water holding capacity) and two soil Ca levels (0 and 200 mg·kg−1 Ca2+) in a greenhouse experiment, and then measured the Ca uptake, growth, gas exchange parameters, biomass allocation, and leaf traits. Drought induced a reduction in biomass accumulation of poplar cuttings and mulberry seedlings, and the cuttings and seedlings exhibited different biomass allocation patterns in response to drought stress. Under Ca0 treatment, poplar cuttings allocated more biomass to leaves and less biomass to stems under drought conditions, leading to an increased leaf/stem (L/St) ratio and higher SLA than under moist conditions in order to maintain higher Pn, and had enhanced WUE to cope with drought stress. Under the same treatment, mulberry seedlings allocated more biomass to roots and less biomass to stems, leading to an increased root/shoot (R/S) ratio and lower SLA, to improve drought resistance. Ca200 treatment decreased the growth of poplar cuttings and mulberry seedlings, whereas it enhanced the WUE, root growth, and R/S ratio of poplar cuttings and the WUE of mulberry seedlings, and alleviated drought stress in both species.

A response of biomass and nutrient allocation to the combined effects of soil nutrient, arbuscular mycorrhizal, and root-knot nematode in cherry tomato

IntroductionThe biomass and nutrient allocation strategies in plants are fundamental for predicting carbon storage and mineral and nutrient cycles in terrestrial ecosystems. However, our knowledge regarding the effects of multiple environmental factors on biomass and nutrient allocation remains limited.MethodsHere we manipulated soil composition (three levels), arbuscular mycorrhizal fungi inoculation (AMF, five levels), and root-knot nematode inoculation (RKN, two levels) using random block design to reveal the effects of these factors on biomass and nutrient allocation strategies of cherry tomato.Results and DiscussionOur results showed that biomass and nutrient allocation were affected by soil composition, AMF and RKN individually or interactively. The biomass and nutrient allocation in cherry tomato shows different adaptation strategies responded to the joint action of three factors. The reduction of soil nutrients increased belowground biomass allocation, and aboveground nitrogen and phosphorus concentration. AMF colonization increased aboveground biomass allocation and reproductive investment and promoted aboveground nitrogen and phosphorus inputs. Cherry tomato can mitigate the stress of RKN infection by investing more biomass and nutrients into belowground organs. Our study showed that plants can adjust their survival strategies by changing biomass and nutrient allocation to adapt to variation in soil abiotic and biotic factors. These findings contribute to our understanding of the adaptive processes of plant biomass and nutrient allocation strategies under multiple environmental factors.

Ampelocalamus luodianensis (Poaceae), a plant endemic to karst, adapts to resource heterogeneity in differing microhabitats by adjusting its biomass allocation

Karst landscapes typically have extremely poor soil fertility, water retention, and water holding capacity, making these landscapes extremely unusual among terrestrial ecosystems. Owing to the complexity of karst areas on a microsite level, a variety of different microhabitats have often been created in a very small area in karst areas, and the differences have facilitated the differentiation of species within the region. This study involved an experiment on Ampelocalamus luodianensis (Poaceae), a bamboo species that specializes in karst habitats, to discover the adaptation strategies this plant uses in this area. Furthermore, a random sampling method was used to measure different variables and their correlation, such as plant biomass, soil temperature, soil mechanical composition, alkali nitrogen, Olsen-K, PZOS (meaning effective phosphorus), soil water content, pH, and organic matter. The findings showed that the distribution of biomass varied in different years in the same habitat. In particular, the ratio of above-ground biomass to below-ground biomass during a quadrennium at the earthy surface was visibly lower than in the remaining three microhabitats. Also, the highest above-ground biomass to below-ground biomass ratios of annual, triennial, and quadrennial A. luodianensis were of those plants living in stone crevices, while biennial ratios of plants in stone gullies were affected by the mechanical composition of soil and by temperature. In conclusion, plant biomass allocation in A. luodianensis was affected by a combination of environmental factors. Thus, the biomass allocation strategy of A. luodianensis was in line with the isokinetic/allometric biomass allocation theory, which was relevant to soil mechanical composition and temperature, perhaps caused by the plant itself and the special karst environment. Data is contained within the article or supplementary material.

Different biomass allocation strategies of geophytes and non-geophytes along an altitude gradient

Biomass allocation strategies among geophytes and non-geophytes generally determine the ecological adaptation and impacts of herbaceous plants. Although geophytes and non-geophytes are key components of the biodiversity of subtropical forest ecosystems, strategies for biomass allocation of both remain unknown. In this study, 695 individual herbaceous plants were collected from low, middle, and high altitude regions in Qianjiangyuan National Park. We analyzed the biomass and allometric trajectories of the leaves, stems, roots, and underground storage organs of whole herbs, geophytes, and non-geophytes. The results showed that: (1) The overall allometric trajectory of understory herbs changed with increase in altitude. Allocation was reduced to stems and leaves and increased to roots. (2) In geophytes, the allocation was reduced to leaves and stems and increased to underground storage organs and roots, which follows the optimal partitioning theory. In the biomass trade-off of the aboveground parts, the stem is preferred. (3) However, the allometric trajectories of non-geophytes are less susceptible to changes in the altitude, and the biomass allocation strategy depends only on plant size which follows allometric partitioning theory. In the biomass trade-off of the aboveground parts, the leaves are preferred. Totally, geophytes and non-geophytes adopted different biomass allocation strategies as adaptations to altitudinal changes in the environment. The plant functional type is the major determinant of biomass allocation in herb species. This study has implications for the management practices of herbaceous plants and predicting changes in understory vegetation.