Plant Carbon Research Articles

Crucial role of fungi in environmentally sustainable agriculture

To produce more, better and safer food we must be able to do so while promoting the sustainable use of agricultural resources. The increase in agricultural production is currently through the use of pesticides, fertilizers, and developments in plant breeding and genetic skills. In naturally existing ecosystems, rhizospheric soils have biological living beings to favor the plant development, nutrient assimilation, stress tolerance, disease deterrence, carbon seizing and others. Fungi are among the most widely distributed organisms on Earth and are of great environmental importance. Mycorrhizal fungi, bacteria, actinomycetes, etc. solubilize nutrients and assist the plants in uptake by roots. Amongst them, vesicular/arbuscular mycorrhizal fungi (AMF) have key roles in the natural ecosystem, as the majority of the terrestrial plants form association with AMF. This symbiosis confers benefits directly to the host plant’s growth and development through the acquisition of phosphorus (P) and other mineral nutrients from the soil. They may also enhance the protection of plants against pathogens, increase plant diversity and have the potential to enhance plant growth under stressful environments. In this article, the sustainability and environmental aspects of agriculture, and the basic concepts of fungi will be reviewed to justify our point of view about the tremendous importance of fungi towards an environmentally sustainable agriculture.

Plant pests influence the movement of plant‐fixed carbon and fungal‐acquired nutrients through arbuscular mycorrhizal networks

Abstract Plants typically interact with multiple, co‐occurring symbionts, including arbuscular mycorrhizal (AM) fungi which can form networks, connecting neighbouring plants. A characteristic aspect of the mycorrhizal symbiosis is the bidirectional exchange of nutrients between host plants and fungal partners. Concurrent interactions with competing organisms such as aphids or potato cyst nematodes (PCN) can disrupt the carbon‐for‐nutrient exchange between plants and AM fungi. However, the role of mycorrhizal networks (MNs) in mediating these interactions remains unclear. Using isotope tracing in multi‐plant experimental systems, we investigated the movement of plant photosynthates and fungal‐acquired soil phosphorus through MNs and the interactive effects of PCN infection on this. We found evidence of preferential allocation of fungal‐acquired phosphorus to plants that were not infected by PCN compared with infected neighbours. Contrary to previous findings using single plants, we did not detect a PCN‐induced reduction in the amounts of plant carbon delivered to AM fungi in multi‐plant systems. However, the MN(s) moved plant‐fixed carbon away from PCN‐infected host plants, regardless of the PCN infection status of the neighbouring plant host. Our work highlights the responsiveness of MNs to interactions with below‐ground organisms. It also strengthens the argument for a more mycocentric view of AM–plant symbioses. Experimental designs of increasing ecological complexity are needed for a more comprehensive understanding of the carbon‐for‐nutrient dynamics in AM fungi–plant networks. This will, in turn, elucidate the role of AM fungi in terrestrial carbon cycling and their function in agricultural systems. Read the free Plain Language Summary for this article on the Journal blog.

Agricultural carbon credits: A pathway to environmental sustainability

Climate change and ensuring food security for a rapidly growing global population are two of the biggest challenges in agriculture. To meet the commitments made in the Paris Climate Agreement, it is important to use effective methods for managing soil that can help sequester and stabilise carbon. Conservation agriculture has a huge potential to sequester carbon in plants and soil, making it a viable option for carbon trading despite its significant contribution to global greenhouse gas emissions. Carbon sequestration can be achieved through sustainable practices such as adopting conservation agriculture, crop rotation, cover crop cultivation, crop residue incorporation or mulching, effective management of nutrient supply to crops, and transforming towards organic agriculture and agroforestry. These practices promote food security and environmental improvement and help mitigate global warming. Carbon pricing mechanisms are policies that impose a cost on carbon pollution, encouraging people and organisations to choose low-carbon options and reduce their emissions. Agricultural producers can benefit from carbon trading by earning extra revenue by selling their excess carbon credits to those who emit higher amounts of greenhouse gases. Carbon credit systems in agriculture are still in the early stages, so farmers may have more opportunities to participate in future carbon trading.

Higher temperature accelerates carbon cycling in a temperate montane forest without decreasing soil carbon stocks

Global warming is expected to accelerate the cycling of soil organic carbon (SOC) and the assimilation of new carbon, but the net effect of those counteracting accelerations and their ultimate effects on SOC are still uncertain. This hinders the prediction of long-term changes in biospheric carbon stocks and SOC-climate feedbacks. Here, we studied the long-term effect of temperature on carbon cycling across a 3.2 °C altitudinal temperature gradient in a temperate forest ecosystem in New Zealand. Across the gradient, soil respiration rates increased with increasing temperature from 9.0 to 10.4 tC ha−1 yr−1, but SOC stocks down to 85 cm depth also tended to increase, from 154 to 176 tC ha−1, albeit non-significantly (P = 0.06). This system was able to maintain higher soil respiration rates at higher temperatures without reducing SOC because the higher respiration rates were sustained by higher litterfall rates. Aboveground litterfall increased from 1.8 to 2.4 tC ha−1 yr−1 and estimated belowground C inputs increased from 7.2 to 8.0 tC ha−1 yr−1 along the temperature gradient. These higher fluxes were associated with significantly (P < 0.05) increased biomass at higher temperatures. As a direct measure of the effect of temperature on carbon cycling processes, we also calculated the turnover rate of forest litter which increased about 1.4-fold across the temperature gradient. This study demonstrates that higher temperatures along the thermal gradient increased plant carbon inputs through enhanced gross primary production, which counteracted SOC losses through temperature-enhanced soil respiration. These results suggest that temperature sensitivities of both plant carbon inputs and SOC losses must be considered for predicting SOC-climate feedbacks.

Applications of Carbon Capture Technologies in Steel and Cement Industries

As problems such as the increase in extreme weather, rising sea levels, and social inequality continue to sharpen with the intensifying climate change, changes are demanded. The cement and iron and steel industries are among the major spheres responsible for the rising global temperature. Carbon reduction methods cannot fully solve the problem and help these industries reach carbon-neutral emissions. Therefore, carbon capture (CC) technology is urgently needed. This article introduces the application of pre-combustion carbon capture (PreCCC), post-combustion carbon capture (PostCCC), and oxyfuel combustion carbon capture in the cement industry and the iron and steel industry. Research has shown that oxyfuel combustion is one of the most assuring pathways to reach carbon neutrality in cement plants since problems of temperature management can be solved by recycling part of the fuel gases, and its cost is relatively lower than the other methods. However, PostCCC is a better solution in the iron and steel industries. Although technological innovations in physical absorption and chemical absorption are still needed, PostCCC can mitigate a large portion of steel plants carbon footprint. Carbon capture intensity can be increased with further technological development in combining PostCCC and oxygen-rich combustion. The combination of different pathways may be a novel hypothesis, but it has a great possibility of alleviating the carbon emission of the industrial sector.

Perennial Fodder Crops as a Tool for Soil Carbon Management in Agroecosystems

Carbon sequestration, typically referred to as carbon storage is defined as the “long-term storage of carbon in plants, soils, geologic formations and the ocean, which occurs both naturally and as a result of anthropogenic activities”. With respect to agricultural sector, carbon sequestration is viewed as the capability of agriculture lands to absorb carbon dioxide from the atmosphere. Out of the different ways in play, cultivation of fodder crops turns out to be promising due to its high biomass production, root proliferation, mostly perennial nature, suitability for wastelands and most importantly as the feed for livestock. Restoration of degraded lands, adoption of pasture-based agroforestry systems, inclusion of grasses, sowing of improved forage species, grazing management, nutrient and water management are strategies that aid in improving carbon sequestration in fodder production systems. Perennial fodder grasses and fodder legumes such as alfalfa are excellent for carbon storage as they do not require replanting after each harvest which avoids soil disturbances that usually associate with annual crops. Carbon neutral methods of cultivation is greatly hoped to convert agriculture from a source of carbon to a permanent sink of carbon at a faster pace.

The metabolic profiles of phenolic acids and aromatic amino acids in the Orobanche crenata parasite and its host faba bean at different infestation stages

Orobanche crenata is a root holoparasite that depends on its host for nutritional requirements. The shikimate pathway that metabolizes about 30% of the assimilated carbon in photosynthetic plants plays a role in host-parasite relationships. Aromatic amino acids (AAAs) and phenolic acids are derived from the shikimate pathway and serve as precursors of a wide number of primary and secondary metabolites. The effects of the O. crenata parasite on the phenolic acid and AAA profiles of two faba bean varieties and the differences of these compounds between the host organs and attached parasite at infestation stages were studied. Hosts and attached parasites were collected and divided, depending on the stage of parasite development, into four stages. The results revealed that phenolic acids and free AAAs tended to increase in parasitized roots compared to those of healthy roots, and the greatest increase in phenolic contents occurred at the first infestation stage. Syringic acid was observed to be unique to the parasite. Profiles of phenolic acids and AAAs were changed during the developmental stages of the parasite and differed from those of its host. Caffeic in the parasite reached more than 100 times that in Nubaria 4 host roots at the fourth infestation stage. Free phenylalanine in the parasite ranged between 2.2 and 5.5 times its level in host roots at all infestation stages. This study provides much evidence that indicates O. crenata is able to self-regulate its phenolic and AAA metabolites during its developmental stages, which differ from those of its host.

Sugars, Lipids and More: New Insights Into Plant Carbon Sources During Plant-Microbe Interactions.

Heterotrophic microbes rely on host-derived carbon sources for their growth and survival. Depriving pathogens of plant carbon is therefore a promising strategy for protecting plants from disease and reducing yield losses. Importantly, this carbon starvation-mediated resistance is expected to be more broad-spectrum and durable than race-specific R-gene-mediated resistance. Although sugars are well characterized as major carbon sources for bacteria, emerging evidence suggests that plant-derived lipids are likely to be an essential carbon source for some fungal microbes, particularly biotrophs. Here, we comprehensively discuss the dual roles of carbon sources (mainly sugars and lipids) and their transport processes in immune signalling and microbial nutrition. We summarize recent findings revealing the crucial roles of lipids as susceptibility factors at all stages of pathogen infection. In particular, we discuss the potential pathways by which lipids and other plant carbon sources are delivered to biotrophs, including protein-mediated transport, vesicle trafficking and autophagy. Finally, we highlight knowledge gaps and offer suggestions for clarifying the mechanisms that underlie nutrient uptake by biotrophs, providing guidance for future research on the application of carbon starvation-mediated resistance.

Improving Process-Based Modelling to Simulate the Effects of Low-Temperature Stress During Pre-Anthesis on the Quality Characteristics of Wheat Grains.

Low temperatures in late spring pose a potential threat to the maintenance of grain yield and quality. Despite the importance of protein and starch in wheat quality, they are often overlooked in models addressing climate change effects. In this study, we conducted multiyear environment-controlled phytotron experiments and observed adverse effects resulting from low-temperature stress (LTS) on plant carbon and nitrogen dynamics, grain protein and starch formation, and sink capacity. We quantified the relationships between low temperature during the jointing and booting stages and plant nitrogen uptake, grain nitrogen accumulation, grain starch accumulation, grain setting, and potential grain weight using source-sink relationship-based methods. The LTS factor was introduced to account for the cultivar-specific to LTS at different growth stages. Compared with the original model, the improved model produced fewer errors when simulating aboveground nitrogen accumulation, grain protein concentration, grain starch concentration, grain starch yield, grain number, and grain weight under LTS, with reductions of 60%, 71%, 73%, 58%, 50% and 65%, respectively. The improvements in the model enhance its mechanism and applicability in assessing short-term successive frost effects on wheat grain quality. Furthermore, when using the improved model, special attention should be given to the low-temperature sensitivity parameters.

Nitrogen induced soil carbon gains are resistant to loss after the cessation of excess nitrogen inputs

Nitrogen (N) deposition has increased soil carbon (C) storage across eastern US temperate forests by reducing microbial decomposition. However, the fate of these N-induced soil C gains are uncertain given strong declines in N-deposition rates and rising soil temperatures. As N deposition has reduced soil pH and plant C investments into the rhizosphere, we compared the extent to which removing limitations to microbial decomposition by increasing soil pH, adding artificial root exudates, or elevating soil temperature would increase microbial decomposition in soils that have and have not received excess N inputs. We hypothesized that alleviating these microbial decomposition limitations would prime soil C losses from soils that have received excess N inputs. To test this hypothesis, we conducted a soil microcosm experiment where we compared microbial respiration, microbial biomass, and soil enzyme activity in soils from an unfertilized watershed and a previously N-fertilized watershed 4 years after the end of a 30-year N deposition experiment at the Fernow Experimental Forest in West Virginia. In both watersheds, we found that removing pH, plant carbon, or temperature limitations to decomposition stimulated microbial respiration. However, microbial decomposition and soil C losses were consistently lower in the previously N-fertilized watershed across all treatments. This response, coupled with a lack of differences in microbial biomass between watersheds and treatments, suggests that long-term N fertilization has fundamentally altered soil microbial communities and has led to a sustained impairment of the ability of the microbial community to decompose soil organic matter. Collectively, our results indicate that the legacy effect of N deposition on microbial communities may influence the persistence of soil C stocks in the face of global change.

Monitoring weekly δ 13С variations along the cambium-xylem continuum in the Canadian eastern boreal forest.

Intra-annual variations of carbon stable isotope ratios (δ13C) in different tree compartments could represent valuable indicators of plant carbon source-sink dynamics, at weekly time scale. Despite this significance, the absence of a methodological framework for tracking δ13C values in tree rings persists due to the complexity of tree ring development. To fulfill this knowledge gap, we developed a method to monitor weekly variability of δ13C in the cambium-xylem continuum of black spruce species [Picea mariana (Mill.) BSP.] during the growing season. We collected and isolated the weekly incremental growth of the cambial region and the developing tree ring from five mature spruce trees over three consecutive growing seasons (2019-2021) in Simoncouche and two growing seasons (2020-2021) in Bernatchez, both located in the boreal forest of Quebec, Canada. Our method allowed for the creation of intra-annual δ13C series for both the growing cambium (δ13Ccam) and developing xylem cellulose (δ13Cxc) in these two sites. Strong positive correlations were observed between δ13Ccam and δ13Cxc series in almost all study years. These findings suggest that a constant supply of fresh assimilates to the cambium-xylem continuum may be the dominant process feeding secondary growth in the two study sites. On the other hand, rates of carbon isotopic fractionation appeared to be poorly affected by climate variability, at an inter- weekly time scale. Hence, increasing δ13Ccam and δ13Cxc trends highlighted here possibly indicate shifts in carbon allocation strategies, likely fostering frost resistance and reducing water uptake in the late growth season. Additionally, these trends may be related to the black spruce trees' responses to the seasonal decrease in photosynthetically active radiation. Our findings provide new insights into the seasonal carbon dynamics and growth constraints of black spruce in boreal forest ecosystems, offering a novel methodological approach for studying carbon allocation at fine temporal scales.

Evaluating Carbon Sequestration and Biodiversity in Cocoa Agroforestry Systems: A Case Study from the Man Region, Côte d'Ivoire

Aims: Cocoa-based agroforestry systems in the Man region of Côte d'Ivoire are essential for balancing agricultural productivity and environmental preservation. This study assessed these systems regarding plant biodiversity conservation and carbon sequestration. Study Design and Methodology: The research was carried out in 21 cocoa plantations, aged between 14 and 32 years, across 60 botanical inventory plots, each measuring 10 by 20 meters. Tree heights and diameters were recorded to estimate Above Ground Biomass (AGB) using the equation AGB = 0.0673 × (ρD²H)0.976, where D is diameter, H is height, and ρ is specific density. Below Ground Biomass (BGB) was calculated as BGB=AGB×0.24, while total biomass (BT) was obtained as BT=AGB+BGB. Carbon stock (C) was derived using C=BT×0.5. Statistical analysis was applied to compare mean carbon stocks across different plantation ages. Results: The plantations, ranging from 8 to 32 years old, showed a diversity of companion species. The diversity of companion species in cocoa agrosystems varies from 4 in 8–10-year-old plantations to 12 in 14- and 15-year-old plantations. Carbon sequestration was age-dependent: younger plantations (5-10 years) sequestered 19.77 ± 2.32 tonnes per hectare, plantations aged 10-15 years stored 133.70 ± 253.50 tonnes, while middle-aged plots (15-20 years) reached 398.76 ± 861.51 tonnes. The oldest plantations (30-35 years) sequestered 137.94 ± 280.31 tonnes. Effective plantation management increased both carbon sequestration and biodiversity. Conclusion: The study highlights the importance of species diversity and continuous management in cocoa-based agroforestry systems. Optimized agroecological practices enhance biodiversity conservation and carbon sequestration, providing practical insights for stakeholders involved in agricultural sustainability, biodiversity conservation, and climate change mitigation. Cocoa agroforestry aligns economic and environmental objectives, offering a sustainable agricultural model.

Assessing Carbon Stocks and Ecosystem Functioning in Char (Buchanania lanzan) Forests of Central India

The present study assessment of plant community structure, carbon stock and CO2 sequestration of char (Buchanania lanzan) dominant forest sites in Central India during 2020-22. The forest vegetation was analysed using 20 quadrats (each 10 x 10 m in size for tree layers, 5 x 5 m in size for sapling layers and 1 x 1 m size for seedling layers) within the representative one-hectare plot on each site. The biomass, carbon stock, and carbon dioxide sequestration from three district (Mahasamund, Gariaband, and Kabirdham) char dominated forest sites of dry deciduous forests in Central India were estimated using the non-destructive allometric equation approach. The results revealed that the density of tree, sapling and seedling were ranged from 430-605 stems ha-1, 120-600 stems ha-1 and 28000-34500 stems ha-1, respectively. The basal area of tree and sapling layers were varied from 18.15-29.68 m2 ha-1 and 0.33-1.04 m2 ha-1, respectively. The diversity indices of tree layer viz; Shannon index, Simpson index, Evenness, species richness and beta diversity were ranged from 2.40-2.72, 0.17-0.22, 1.08-1.18, 2.26-3.11 and 5.0-6.0, respectively on different forest site in Central India. The total biomass, carbon stock and CO2 sequestration potential of tree layers were varied from 105.72-216.96 Mg ha-1, 50.22-103.06 Mg ha-1 and 184.29-378.22 Mg ha-1, respectively on char dominant various forest sites in Central India. The correlation coefficients were statistically significant performed between basal area and biomass, carbon stock and CO2 sequestration potential with R2 values of 0.988 at p&lt;0.01 levels. After doing this study, it can be concluded that estimating the biomass and carbon stock in Central India will be useful for managing forests sustainably.

The Properties of Microorganisms and Plants in Soils after Amelioration

Soil, as a vital foundation of the Earth’s biosphere, supports plant growth, carbon storage, water cycling, and nutrient supply, making it a crucial resource for ensuring global food production and ecosystem health [...]

Belowground diversity drives multifunctionality in grazing pastures on the eastern Tibetan Plateau

Livestock grazing can alter ecosystem structure, functions, and services across diverse biomes, with grazing intensity being a key factor affecting grassland function. Although the effects of grazing on plant and soil properties have been extensively studied, the effects of grazing intensity on biodiversity and ecosystem multifunctionality (EMF) remain largely unexplored. Therefore, this study addresses this gap using 28 indicator variables from a well-controlled yak grazing intensity experiment in alpine meadows on the eastern Tibetan Plateau. The results showed that aboveground diversity (calculated using plant species richness and insect diversity) exhibited a hump-shaped and significant response to increasing grazing intensity, multidiversity (whole-ecosystem biodiversity) and belowground diversity (calculated using nematode richness and microbial diversity) showed no significant response, and EMF significantly declined. Grazing decreased carbon and nitrogen cycling indices (calculated by carbon and nitrogen in plants and soils), but did not affect phosphorus cycling. Structural equation modelling indicated that EMF was directly affected by grazing intensity and belowground diversity (i.e., nematode and fungal diversity), rather than by multidiversity, aboveground diversity, and plant pathogens. Grazing-induced decreases in plant pathogens showed no direct or indirect effects on EMF but increased multidiversity and aboveground diversity. Overall, our results highlight the critical role of conserving belowground diversity in promoting and maintaining multifunctionality in grazing pastures on the Tibetan Plateau.

Simple and Accurate Representation of Cumulative Nighttime Leaf Respiratory CO2 Efflux.

Leaf respiratory carbon loss decreases independent of temperature as the night progresses. Detailed nighttime measurements needed to quantify cumulative respiratory carbon loss at night are challenging under both lab and field conditions. We provide a simple yet accurate approach to represent variation in nighttime temperature-independent leaf respiratory CO2 efflux in environments with both stable and fluctuating temperatures, which requires no detailed measurements throughout the night. We demonstrate that the inter- and intraspecific variation in the cumulative leaf respiratory CO2 efflux at constant temperature, at any length of night, scales linearly with the inter- and intraspecific variation in initial measurement of leaf respiratory CO2 efflux at the same temperature at the beginning of the night. This approach informs large-scale predictions of cumulative leaf respiratory CO2 efflux, which is needed to understand plant carbon economy in global change studies as well as in global modeling and eddy covariance monitoring of the land-atmosphere exchange of CO2.

Relationship between seagrass community structure and carbon stocks on the coasts of Karimunjawa Marine National Park, Indonesia

The seagrass ecosystem is considered one of the most effective coastal ecosystems in storing carbon. Carbon stock estimation for a certain ecosystem is highly affected by factors such as species diversity and habitat type. This study aims to investigate the relationship between plant community structure and carbon stocks in the seagrass ecosystem using a case study of six coastal sites in Karimunjawa Marine National Park, Indonesia. In this region, eight seagrass species were recorded, i.e., Enhalus acoroides, Thalassia hemprichii, Cymodocea rotundata, Halodule pinifolia, Halophila ovalis, Halophila minor, Syringodium isoetifolium, and Oceana serrulata. From the six study sites, the highest estimated carbon stock was 426.2 Mg C ha−1 (Site 5; Telaga, dominated by E. acoroides). Meanwhile, the lowest estimated carbon stock was 127.4 Mg C ha−1 (Site 4; Koin, dominated by T. hemprichii). The density of E. acoroides was positively correlated with the total seagrass biomass carbon stocks (r = 0.97; p < 0.01), while its dominance was positively correlated with sediment carbon stocks (r = 0.92; p < 0.05) and total seagrass ecosystem carbon stocks (r = 0.92; p < 0.05). Seagrass ecosystems with different community structures showed different carbon storage capacities. Seagrass ecosystems dominated by large-sized species such as E. acoroides showed higher estimated carbon stocks thus suggesting the importance of considering the variability of community structure in managing seagrass ecosystems for carbon sequestration and storage.

Unexpected sustained soil carbon flux in response to simultaneous warming and nitrogen enrichment compared with single factors alone.

Recent observations document that long-term soil warming in a temperate deciduous forest leads to significant soil carbon loss, whereas chronic soil nitrogen enrichment leads to significant soil carbon gain. Most global change experiments like these are single factor, investigating the impacts of one stressor in isolation of others. Because warming and ecosystem nitrogen enrichment are happening concurrently in many parts of the world, we designed a field experiment to test how these two factors, alone and in combination, impact soil carbon cycling. Here, we show that long-term continuous soil warming or nitrogen enrichment when applied alone followed the predicted response, with warming resulting in significant soil carbon loss and nitrogen fertilization tending towards soil carbon gain. The combination treatment showed an unanticipated response, whereby soil respiratory carbon loss was significantly higher than either single factor alone, but without a concomitant decline in soil carbon storage. Observations suggest that when soils are exposed to both factors simultaneously, plant carbon inputs to the soil are enhanced, counterbalancing soil carbon loss and helping maintain soil carbon stocks near control levels. This has implications for both atmospheric CO2 emissions and soil fertility and shows that coupling two important global change drivers results in a distinctive response that was not predicted by the behaviour of the single factors in isolation.

Moderate Red-Edge vegetation index for High-Resolution multispectral remote sensing images in urban areas

Urban green space (UGS) monitoring is significant in optimizing urban planning, protecting the ecological environment, and improving residents’ quality of life. However, in urban environments, shadow interference and the emergence of new construction materials pose challenges to monitoring green vegetation in high-resolution imagery. This study found that existing vegetation indices (VIs), such as normalized difference vegetation index (NDVI) and enhanced vegetation index (EVI), perform inadequately in extracting vegetation in urban areas, resulting in significant omissions and errors. By conducting in-depth analysis and quantitative experiments on the reflectance of typical urban ground objects, this study developed a new vegetation extraction method, the moderate red-edge vegetation index (MREVI), to enhance the extraction accuracy of UGS vegetation from unmanned aerial vehicle (UAV) high-resolution multispectral remote sensing (RS) images. Experimental results demonstrate that MREVI performs exceptionally well in complex urban environments, significantly suppressing non-vegetation areas, achieving an overall accuracy (OA) of 98.6% and a Kappa coefficient of 0.97. This study supports for urban planning, UGS monitoring, and the evaluation of urban plant carbon sequestration capacity.

Comparative Analysis of Water Stress Regimes in Avocado Plants during the Early Development Stage.

The avocado cv. Hass requires a suitable rootstock for optimal development under water stress. This study evaluated the performance of two avocado rootstocks (ANRR88 and ANGI52) grafted onto cv. Hass under four water stress conditions, 50% and 25% deficit, and 50% and 25% excess during the nursery stage. Plant height, leaf area (LA), dry matter (DM), and Carbon (OC) content in the roots, stems, and leaves were measured. Root traits were evaluated using digital imaging, and three vegetation indices (NDVI, CIRE, and MTCI) were used to quantify stress. The results showed that genotype significantly influenced the response to water stress. ANRR88 exhibited adaptation to moderate to high water deficits. ANGI52 adapted better to both water deficit and excess, and showed greater root exploration. LA and DM reductions of up to 60% were observed in ANRR88, suggesting a higher sensitivity to extreme changes in water availability. More than 90% of the total OC accumulation was observed in the stem and roots. The NDVI and the MTCI quantified the presence and levels of stress applied, and the 720 nm band provided high precision and speed for detecting stress. These insights are crucial for selecting rootstocks that ensure optimal performance under varying water availability, enhancing productivity and sustainability.