Basal Stem Diameter Research Articles

Populus deltoides is suitable for moist and short-term flooded soil conditions on the basis of its relative growth rate and stoichiometry

To understand the effects of water stress on plant growth, nutrients distribution and their stoichiometry in different organs of poplar seedlings, and further explore the validation of growth rate hypothesis (GRH) under water stress treatments. Poplar seedlings (Populus deltoides 'Nanlin 3804') were grown under drought (D), normal water management (CK), low-level flooding (LF), high-level flooding (HF) and high-level flooding followed by flood recovery (FR) treatments in 60 days. Poplar seedling growth, nutrients contents and stoichiometry among different treatments were analyzed. The seedlings had greater relative growth rate of biomass, height and stem-basal diameter (BRGR, HRGR, and SRGR, respectively) under flooding treatments, especially in FR treatment (P < 0.05). Among different organs, stem had the highest BRGR. The N, P and K concentrations were highest in D treatment (P < 0.05). Leaves and stems had greater nutrient concentrations and stoichiometries than roots under different treatments (P < 0.05). The plant stoichiometry were positively correlated with BRGR and HRGR but negatively correlated with SRGR from whole-plant perspective. In organ level, BRGR were negatively correlated with root stoichiometry, but were positively correlated with stem and leaf stoichiometry. Poplar seedlings are suitable for cultivation in relatively moist soil or under short-term periodic flooding conditions. This study provides a scientific basis for the cultivation of high-quality seedlings and the selection of suitable afforestation sites for existing poplar clones.

Exploring genetic variability, diversity and trait associations in sunnhemp (Crotolaria juncea L.) accessions for yield improvement

Sunnhemp (Crotolaria juncea L.) is an important fibre crop known for its rapid growth and ability to improve soil fertility, making it a vital component of sustainable agriculture. However, to enhance its productivity and meet the increasing demand for high-quality fibre, it is crucial to identify and utilize genetically diverse genotypes with superior yield traits. The present study was conducted at the Tamil Nadu Rice Research Institute, Aduthurai, Tamil Nadu, during the Kharif seasons of 2021 and 2022 to assess genetic variability and character association for yield and its component traits among 67 sunnhemp genotypes. Multivariate analyses, including principal component analysis (PCA) and cluster analysis, were conducted using R software to dissect the phenotypic diversity among the genotypes. The results revealed substantial genetic variability for yield and its associated traits, indicating a promising potential for genetic improvement. Genotypes ADSH 1750, ADSH 1701, ADSH 1736, ADSH 1715, and ADSH 1742 exhibited superior performance in key yield-related traits, making them valuable candidates for future breeding programs focused on developing high-yielding, high-fibre varieties. Cluster analysis delineated four distinct clusters, with Clusters I and IV showing significant divergence and highlighting the presence of unique genetic material. Key plant production traits such as plant height, leaf breadth, basal stem diameter, yield, and number of leaves were the primary contributors to the first two principal components. These findings suggest that direct selection based on these traits could effectively improve biomass yield in future sunnhemp breeding efforts, contributing to the advancement of sustainable fibre crop production.

The Impact of Salvage Logging on Deadwood Decomposition and Forest Regeneration: A Case Study in Tatra National Park, Slovakia

In November 2004, a severe windstorm destroyed large portions of the spruce-dominated forests in the Tatra National Park (northern Slovakia). This study focused on the status of deadwood and its influence on post-disturbance forest regeneration 18 years after the destruction. Since some disturbed areas were salvaged and others were not, we could compare the situations between these two management approaches. Therefore, 40 research sites (20 salvaged and 20 unsalvaged) were analyzed; each contained four satellite plots, i.e., circle-like areas with a radius of 3 m. We measured the diameter of deadwood and its decay status (classes 1–5) and recorded the sizes (stem base diameter and height) as well as species of young trees. Our results showed that while salvage conditions and contact with soil stimulated deadwood decomposition, the diameter of logs was not a significant factor. The highest decay class (3.83) was found in deadwood in salvaged areas and touching the soil, while the lowest decay class (3.10) was found in deadwood in unsalvaged areas and in the case of logs not touching the soil. Although carbon content (based on the percentage of wood mass) did not change with the decay class, wood density decreased sharply with decay, and deadwood moisture increased. We also found that the different post-disturbance management strategies influenced forest regeneration. Significantly higher tree diversity was observed in salvaged sites (5.40 species per plot) compared to unsalvaged sites (3.85 species per plot). At the same time, while sites with logging were predominantly covered by broadleaved species, those without logging were typically dominated by Norway spruce (Picea abies L. Karst). Our findings suggest that although salvage logging reduced the carbon and total water content in deadwood, it can promote tree species diversity. Therefore, the currently prevailing opinion about the exclusively negative effects of salvage logging on the forest environment should be accepted with caution, and local conditions must be considered before making broad judgments.

ROOT AND MORPHOLOGICAL CHARACTERISTICS OF EUCALYPTUS SEEDLINGS PRODUCED IN BIODEGRADABLE CONTAINERS

The objective of this study was to evaluate the nursery and field development of eucalyptus seedlings produced in biodegradable containers (BC), based on morphological and root characteristics, compared to the conventional method in 55-cm³ tubes. The experiment was conducted in a completely randomized experimental design, using a 3×2 factorial arrangement consisting of three types of containers (55-cm³ tubes; 76-cm³ BC; and 115-cm³ BC) and two eucalyptus clones (CO-1407 and AEC-144). The parameters evaluated in the nursery were: shoot height (SH); stem base diameter (SBD); SH-to-SBD ratio; shoot, root, and total fresh and dry weights; and total number of roots. The parameters evaluated in the field were: SH; SBD; and root distribution. Considering the evaluated characteristics, the use of 115-cm³ BC enabled the development of high-quality seedlings in all evaluation phases. BC-produced seedlings presented better quality and performance in the field. Seedlings produced in 55-cm³ tubes presented lower values for all morphological parameters evaluated in the nursery, as well as in the field up to 120 days after planting.

Vegetative growth response and in vitro evaluation of three multipurpose fodder tree leaves and shrubs as potential feeds for farm animals

In a completely randomized design, the vegetative growth and nutritive value of three tree leaves Tectona grandis, Gmelina arborea, and Acacia mangium compared to berseem (Trifolium alexandrinum) hay as a standard high-quality roughage for ruminants were studied. Growth, chemical composition, in vitro gas production (GP), and fermentation characteristics for 48 h of incubation were measured. Results of measured growth parameters showed that the highest mean value of total height, stem base diameter, crown width, shoot fresh weight, and shoot dry weight were observed in Gmelina arborea, Tectona grandis, and Acacia mangium, respectively. Gmelina arborea had higher (P < 0.05) concentrations (%) crude protein (CP) and lower acid detergent fiber (ADF) compared to berseem hay. The lowest (P < 0.05) CP was observed with Tectona grandis; however, it had more (P < 0.01) neutral detergent fiber (NDF) compared to the berseem hay. All tree leaves had higher (P < 0.05) concentrations (%) of total phenolics, and total tannins compared to the berseem hay. Furthermore, Acacia mangium had the lowest GP (P < 0.01) GP (mL/g DM) and the rate (h) of GP (P < 0.01), while had the highest (P < 0.05) lag of GP (h) compared to berseem hay. Acacia mangium showed the lowest methane production (mL/g DM) and the highest methane production expressed as mL/g degraded DM (dDM), with no significant differences between Gmelina arborea, Tectona grandis, and berseem hay. At the same time, Tectona grandis showed the highest (P < 0.05) total (mM) and individual (%) short chain fatty acids concentrations compared to berseem hay. Acacia mangium showed the lowest (P < 0.01) truly degraded DM and organic matter (mg/g incubated) and protozoal count (P < 0.05) (105/mL). Also, Acacia mangium had lower (P < 0.05) ammonia-N concentration (mg/dL), metabolizable energy (MJ/kg DM), and microbial protein production (mg/g DM). Overall, Tectona grandis and Gmelina arborea are more recommended than Acacia mangium due to their higher rumen fermentation characteristics and nutrient degradability; however, Acacia mangium has an importance from an environmental view as it had lower methane production compared to other plants.

β values obtained by linear regression models of morpho-physiological and biochemical variables as novel drought stress estimators in Capsicum annuum varieties

Capsicum annuum varieties are highly sensitive to drought. Under water stress conditions, these can show yield losses of up to 70 %. Due to the above, this work proposes a novel approach to obtain estimators of drought stress based on linear regression models for morpho-physiological and biochemical variables in jalapeño pepper (C. annuum cv. jalapeno M), bell pepper (C. annuum cv. california wonder), and serrano pepper (C. annnuum cv. serrano tampiqueno). Jalapeno pepper plants were grown for 69 days under permanent water deficit conditions at 40, 60, 80 % and 100 % of field capacity (FC) (100 % FC as control). Throughout the crop cycle, we monitored the plant's height and weight, basal stem diameter, transpiration, photosynthesis, stomatal conductance, NDVI, and proline. This monitoring allowed us to obtain linear regression models from the accumulated values for these variables, from which the slope values (β) were used as estimators of drought stress using the interval estimation method, in the same way, this method was used to estimate water status in bell pepper and serrano pepper. For bell pepper, drought levels of 40, 60, 80 and 100 % FC were imposed for 12 days and serrano pepper 60 and 100 % FC for 63 days. The results showed that this method can be used to estimate drought stress in jalapeno pepper for all the irrigation levels through photosynthesis and NDVI and can be applied for bell pepper and serrano pepper using stem diameter and plant height, and in the case of serrano pepper, NDVI showed adequate results. Also, this work establishes the relationship between the jalapeno pepper responses (morpho-physiological and biochemical) to drought stress during vegetative, flowering, and fruiting stages through a Principal Component Analysis (PCA). The PCA found that interaction among morphological, physiological, and biochemical responses change concerning the phenological stage of the plant. The results suggested several direct and inverse relationships between the variables and showed that drought can be described by stomatal conductance during any phenological stage of the crop. In parallel, the proline content, NDVI and plant height can also describe drought stress during the vegetative and flowering stages. This research is the first to apply this methodology to drought stress estimation in jalapeno, bell pepper, and serrano pepper cultivation. The results could significantly contribute to precision agriculture, sensor development, and water management.

Pattern of water use by Tamarix ramosissima seedlings in floodplains under varied groundwater depths in the hinterland of the Taklimakan Desert

The water use of Tamarix ramosissima Ledeb. seedlings after flooding were analyzed both to explore the maintenance mechanism and pattern of natural regeneration of riparian forest, which will provide a scientific basis for restoration of desert riparian forest and ecosystem stability in the lower reaches of inland rivers of arid regions. This study area was located in the hinterland of the Taklimakan Desert in Xinjiang, China. Tamarix ramosissima seedlings growing on different groundwater depths at the river floodplain were used as the study system. The rooting depths of T. ramosissima seedlings with different basal stem diameters were ascertained by the root excavation method. The water source for the T. ramosissima seedlings was clarified using hydrogen and oxygen stable isotope methods, and the water use efficiency of T. ramosissima seedlings was investigated by stable carbon isotope (δ13C) analysis. As the basal stem diameter classes of the T. ramosissima seedlings increased, their root depths increased. As the groundwater depth increased, the seedlings changed from primarily utilizing deep soil water to utilizing shallow soil water. In the three sample sites, the average depth of water uptake of the seedlings with basal stem diameters of 0–5 mm was 110.5, 44.1 and 39.1 cm, respectively, and that of seedlings with basal stem diameters of 5–11 mm was 83.8, 73.6 and 37.7 cm, respectively. As groundwater depth increased, the average water uptake depth of the seedlings gradually became shallower. There was no significant difference in the δ13C values of leaves under different groundwater depths, indicating that the seedlings were not subjected to water stress. Thus, surface water played a greater role than groundwater in T. ramosissima seedling water utilization. Therefore, when analyzing ecological water conveyance patterns, attention should be paid to T. ramosissima located in areas with deep groundwater. Shallow-rooted seedlings with small basal stem diameters face an increased risk of wilting if they do not receive timely recharges of surface water. Data AvailabilityAll data generated or analyzed during this study are included in this published article.

The Relationship between Allometric Growth and the Stoichiometric Characteristics of Euhalophyte Suaeda salsa L. Grown in Saline-Alkali Lands: Biological Desalination Potential Prediction.

The morphological adjustments of euhalophytes are well-known to be influenced by the soil-soluble salt variation; however, whether and how these changes in morphological traits alter the biomass allocation pattern remains unclear, especially under different NaCl levels. Therefore, an allometric analysis was applied to investigate the biomass allocation pattern and morphological plasticity, and the carbon (C), nitrogen (N), and phosphorus (P) stoichiometric characteristics of the euhalophyte Suaeda Salsa (S. salsa) at the four soil-soluble salt levels of no salt (NS), light salt (LS), moderate salt (MS), and heavy salt (HS). The results showed that soil-soluble salts significantly change the biomass allocation to the stems and leaves (p < 0.05). With the growth of S. salsa, the NS treatment produced a downward leaf mass ratio (LMR) and upward stem mass ratio (SMR); this finding was completely different from that for the salt treatments. When S. salsa was harvested on the 100th day, the HS treatment had the highest LMR (61%) and the lowest SMR (31%), while the NS treatment was the opposite, with an LMR of 44% and an SMR of 50%. Meanwhile, the soil-soluble salt reshaped the morphological characteristics of S. salsa (e.g., root length, plant height, basal stem diameter, and leaf succulence). Combined with the stoichiometric characteristics, N uptake restriction under salt stress is a vital reason for inhibited stem growth. Although the NS treatment had the highest biomass (48.65 g root box-1), the LS treatment had the highest salt absorption (3.73 g root box-1). In conclusion, S. salsa can change its biomass allocation pattern through morphological adjustments to adapt to different saline-alkali habitats. Moreover, it has an optimal biological desalting effect in lightly saline soil dominated by NaCl.

Production of high-quality seedlings of Handroanthus spongiosus (Bignoniaceae), native to a seasonally dry tropical forest

Studies of the use of alternative substrates have enabled producing seedlings of various species with high quality and low cost. The objective of this work was to evaluate the best cultivation conditions for production of Handroanthus spongiosus seedlings. The seeds were collected from five different populations in the state of Pernambuco, Brazil, and cultivated in six substrates: soil, sand, soil + vermiculite, soil + goat manure, soil + vermiculite + goat manure, and soil + goat manure + 30% biochar. We evaluated the emergence, shoot and root length, stem base diameter, shoot and root dry mass, and Dickson quality index. The substrates with addition of organic matter favored increased shoot length, stem diameter and dry mass. The incorporation of goat manure and biochar in the substrates favored the quality of the H. spongiosus seedlings.

Production of tomato seedlings submitted to treatments with foliar application of paclobutrazol

Paclobutrazol (PBZ) is a growth regulator that widely used in horticulture and in the tomato seedling growth to compact the shoots, increase the stem diameter and, root biomass, allowing more tolerance of the seedlings against adverse weather conditions. The objective of this work was to evaluate the rates of paclobutrazol (0, 4, 7, 10 and 13 mg L-1) applied 15 days after sowing by foliar spray on the growth, chemical composition and xylem vessel number of tomato seedlings cultivated in two periods. The PBZ regardless of the application rate reduced the height of tomato seedlings in both growth periods. The basal stem diameter and leaf area were increased with 13 mg L-1 of PBZ. The lignin percentage also increased with 10 and 13 mg L-1 of PBZ as compared to control for both periods. The number of xylem vessel was not affected by PBZ application on the seedlings in the first period. PBZ application at rates of 7 and 10 mg L-1 increased the xylem vessel number in the second period. In general, the application of 13 mg L-1 of PBZ generated seedling more robust to overcome climate adversities.

Spatial distribution of woody plants in relation to mistletoe-infected Vachellia karroo trees in a semi-arid African savanna

By increasing resource heterogeneity, mistletoe-infected trees can restructure plant community processes and distribution patterns. No information is available on how mistletoe-infected Vachellia (Acacia) karroo trees within V. karroo dominated stands are spatially distributed, and on how they influence the spatial patterns of their surrounding conspecifics and heterospecifics. Each woody plant was stem mapped using a cartesian plane (x, y) within three 50×50 m plots located in V. karroo dominated stands in a semi-arid savanna, South West Zimbabwe. Pair correlations g(r) were used for the univariate analysis and Poisson process null models were applied to quantify and detect overall departure from randomness. For the bivariate analysis, pair correlations g12(r) under the null model of independence were used, whilst the mark correlation function (kmm(r)) was used to analyse the correlation of tree canopy area and mistletoe infection intensity. For each plot, size class distributions, based on tree height and basal stem diameter displayed negative J curves, with steep negative regression slopes across the size classes, clearly indicating a strongly recruiting population of V. karroo. The univariate patterns of all trees (infected and non-infected) were consistent with a random pattern, which is attributed to unsystematic mistletoe seed dispersal by birds. The univariate analysis of all woody plants (adults and juveniles) exhibited aggregation at small spatial scales due to the high abundance of clustered seedlings and saplings. At small spatial scales, understory woody plants (both conspecifics and non-conspecifics) were positively associated with mistletoe-infected trees due to mistletoephily which is the facilitation (or nurse protégé interactions) within the more resource-rich mistletoe-infected tree subcanopies. These results provide strong evidence suggesting that the variations in spatial pattern modification by mistletoe-infected trees could further increase spatial heterogeneity in this semi-arid savanna. As such, by increasing heterogeneity, mistletoe-infected trees can increase the resilience of semi-arid savannas in the face of perturbations and stochastic events.

KOMPOSISI MEDIAi TANAM DAN DOSIS PUPUK NPK TERHADAP TUMBUHAN DAN HASIL TANAMAN TERUNG (Solanum melongena L.)

Eggplant is a horticultural crop that is very important for society. One effort to increase production is by providing soil, manure and NPK fertilizer. This research aims to determine the effect of planting media and NPK fertilizer on the growth and yield of eggplant (Solanum melongena L.) variety Mustang F1. This research was conducted in Krajan Hamlet, Kebonsari Village, Kademangan District, Blitar Regency, East Java Province in February-April 2023. The research was prepared using (RAK) factorial with two factors, namely the composition of the planting media (M) and the dose of NPK fertilizer (D). Each treatment had 3 repetitions. Observations will be carried out after 10 days after planting, with an observation interval of 20 days, the observation parameters include plant height, stem base diameter, fruit diameter, and fruit weight. The research results showed that the combination treatment between the composition of the planting media and the dose of NPK fertilizer had a significant effect on plant height, stem base diameter, fruit diameter and fruit weight.

Disentangling the effect of growth from development in size-related trait scaling relationships.

In plant ecology, the terms growth and development are often used interchangeably. Yet these constitute two distinct processes. Plant architectural traits (e.g. number of successive forks) can estimate development stages. Here, we show the importance of including the effect of development stages to better understand size-related trait scaling relationships (i.e. between height and stem diameter). We focused on one common savanna woody species (Senegalia nigrescens) from the Greater Kruger Area, South Africa. We sampled 406 individuals that experience different exposure to herbivory, from which we collected four traits: plant height, basal stem diameter, number of successive forks (proxy for development stage), and resprouting. We analysed trait relationships (using standardized major axis regression) between height and stem diameter, accounting for the effect of ontogeny, exposure to herbivory, and resprouting. The number of successive forks affects the scaling relationship between height and stem diameter, with the slope and strength of the relationship declining in more developed individuals. Herbivory exposure and resprouting do not affect the overall height-diameter relationship. However, when height and stem diameter were regressed separately against number of successive forks, herbivory exposure and resprouting had an effect. For example, resprouting individuals allocate more biomass to both primary and secondary growth than non-resprouting plants in more disturbed conditions. We stress the need to include traits related to ontogeny so as to disentangle the effect of biomass allocation to primary and secondary growth from that of development in plant functional relationships.

Day-neutral jute plant: a hallmark for developing new jute genotype

Jute has more than 100 globally distributed species and is well known for its bast fibre biogenesis as well as its nutritional and medicinal properties. Unfortunately, year-round jute cultivation is highly limited due to its photosensitive character. Therefore, this study was carried out to analyse the flowering behaviour of selected cultivated jute species and their wild relatives to support the year-round supply of jute vegetables. A total of eight jute genotypes viz., Merha red, Merha green, Merha pink, Birol red, Birol green, Birol pink, BJRI deshi pat shak-1, and BINA pat shak-1 were examined, with the latter two selected as controls. In most cases, the six wild species had more surviving plants per unit area, better plant height, and more leaves and branches compared with controls. The highest stem base diameter, leaf area, leaf dry weight, and shoot dry weight were recorded in the control species. Days to 1st flowering, days to average flowering, and days to seed maturity were significantly earlier in wild species compared with the controls, indicating the existence of photo-insensitive characters. The desired vegetative and reproductive properties with high heritability and genetic variability can likely be transmitted from wild germplasm to cultivated jute species through crossing to produce a photo-insensitive jute variety.

Allometric equations to calculate living and dead fuel loads in Mediterranean species

Determining the structure and fuel load is key to know the flammability of vegetation in the Mediterranean Basin where forest fires are frequent. Determine which plant structural variable is best related to living and dead fuel to develop allometric equations in nine species in the Western Mediterranean Basin. In the east of the Iberian Peninsula (Valencia Province), we measured four structural variables (basal stem diameter, height, maximum diameter and perpendicular diameter) that were related, by means of allometric equations, to the living and dead fuel separated into different size classes. We also analyze fuel changes across developmental states of the studied species, and the vertical distribution of dead fuel. General equations that consider all development states can be used to determine living fuel. However to obtain dead fuel, we recommend using specific equations for each development state and fuel fraction for better accuracy. The basal stem diameter was the best structural variable in almost all cases for estimating fuel in the studied species. Dead fuel load throughout species’ ontological development is a key factor to manage Mediterranean plant communities.

Densidade inicial de inóculo, época de avaliação e reprodução de Meloidogyne enterolobii em goiabeira 'Paluma'

ABSTRACT Guava decline is a complex disease caused by the interaction between Meloidogyne enterolobii and Neocosmospora falciformis (Syn.: Fusarium solani). Thus, selecting M. enterolobii-resistant genotypes within the genus Psidium is essential for controlling this disease, and developing a resistant cultivar of Psidium guajava could significantly impact this issue. Thus, the objective of this study was to assess the response of the guava plants of the cultivar Paluma to different densities of M. enterolobii inoculum. Guava seedlings were inoculated with 500, 1,000, 5,000, 10,000, and 20,000 eggs + second-stage juveniles (J2) of M. enterolobii per plant. Root and shoot fresh weights, shoot dry weight, root length, plant height, and stem base diameter were evaluated at 70 and 135 days after inoculation (DAI). Total number of M. enterolobii eggs + J2 in the root system and nematode reproduction factor nematode were assessed. Nematode multiplication in roots was not proportional to increases in initial inoculum density; thus, the best plant responses to nematode multiplication in the evaluated cultivar were found for the lowest tested densities. The reproduction factor decreased as the inoculum density was increased, at both evaluations (70 and 135 DAI).

Polímero hidroabsorvente na produção de mudas de sabiá sob diferentes turnos de rega

ABSTRACT Mimosa caesalpiniifolia Benth is an arboreous species native to the Caatinga commonly utilized for restoration of degraded areas. One factor that can affect its development is water shortage. This denotes the importance of searching for alternatives for improving these plant's tolerance to water shortage, such as the use of water-absorbing polymers known as hydrogels. In this context, the objective of this study was to evaluate the production of M. caesalpiniifolia seedlings under different hydrogel rates and water regimes. The experiment was conducted at the Forest Nursery of the Federal University of Campina Grande, Patos, PB, Brazil. Seeds were sown in 2-liter pots made from halved polyethylene terephthalate bottles, containing a substrate consisted of soil and cattle manure (2:1 v v-1). A completely randomized design with four replications was used, in a 4×2 factorial arrangement consisted of four hydrogel rates in the substrate (0, 1, 2, and 3 g L-1) and two water regimes (daily irrigation and irrigation every 2 days). The following parameters were evaluated at the end of the experiment (75 days after sowing): number of leaves per plant, stem base diameter, plant height, root length, shoot and root dry weights, water relative content, chlorophyll content, gas exchanges, and Dickson quality index. Most of parameters presented no statistically significant difference; however, the hydrogel rate of 2 g L-1 resulted in increased production of M. caesalpiniifolia seedlings, whereas the absence of hydrogel resulted in longer roots, regardless of the water regime.

Encroachment drives facilitation at alpine shrublines

Ongoing encroachment is driving recent alpine shrubline dynamics globally, but the role of shrub-shrub interactions in shaping shrublines and their relationships with stem density changes remain poorly understood. Here, the size and age of shrubs from 26 Salix shrubline populations along a 900-km latitudinal gradient (30°–38° N) were measured and mapped across the eastern Tibetan Plateau. Point pattern analyses were used to quantify the spatial distribution patterns of juveniles and adults, and to assess spatial associations between them. Mean intensity of univariate and bivariate spatial patterns was related to biotic and abiotic variables. Bivariate mark correlation functions with a quantitative mark (shrub height, basal stem diameter, crown width) were also employed to investigate the spatial relationships between shrub traits of juveniles and adults. Structural equation models were used to explore the relationships among conspecific interactions, patterns, shrub traits and recruitment dynamics under climate change. Most shrublines showed clustered patterns, suggesting the existence of conspecific facilitation. Clustered patterns of juveniles and conspecific interactions (potentially facilitation) tended to intensify with increasing soil moisture stress. Summer warming before 2010 triggered positive effects on population interactions and spatial patterns via increased shrub recruitment. However, summer warming after 2010 triggered negative effects on interactions through reduced shrub recruitment. Therefore, shrub recruitment shifts under rapid climate change could impact spatial patterns, alter conspecific interactions and modify the direction and degree of shrublines responses to climate. These changes would have profound implications for the stability of alpine woody ecosystems.

The inadequacy of current carbon storage assessment methods for rewilding: A Knepp Estate case study

Abstract In the context of global climate change mitigation, carbon storage in woody vegetation plays a crucial role. Recognising the value of the i‐Tree Eco model for carbon storage in urban and forestry settings, this study aimed to explore its applicability to rewilded landscapes. Using direct measurements from destructively sampled scrub from the Knepp Estate, our goal was to determine the model's suitability to this landscape. Our findings reveal that these methods are not appropriate for multi‐stemmed trees below browsing height, as we observed no significant relationship between stem basal diameter and height. The i‐Tree tool's assumption of below‐ground biomass being 26% of above‐ground biomass may not be applicable to herbivore‐influenced landscapes. Additionally, we found that, on average, scrub at Knepp had more biomass below the ground than above, with a root:shoot ratio of 1.07, which is more than four times the amount predicted by current models using the 0.26 estimate ratio. This study underscores the need for novel allometric approaches that consider species‐specific biomass and the impact of external factors, such as herbivory, on carbon storage. Accurate carbon accounting in future rewilding projects is essential for their contribution to both biodiversity enhancement and climate change mitigation. While the i‐Tree Eco model provides valuable insights for many ecosystems, our findings suggest that its applicability may be limited in scrubland ecosystems, especially in rewilded landscapes where natural processes create semi‐stable scrub and open wood pastures. Nonetheless, with suitable adjustments or when complemented with other methods, the i‐Tree Eco model could be a valuable tool for specific scrub or rewilding scenarios.

Potentiality of Sustainable Maize Production under Rainfed Conditions in the Tropics by Triggering Agro-Physio-Biochemical Traits Ascertained from a Greenhouse.

A major portion of maize is produced under rainfed conditions in the tropics with relatively poor yield because of the unpredictable and irregular distribution of seasonal rainfall, as well as a decline in pre-rainy season rainfall due to climate change, so identification of sustainable production options is utmost needed. Thus, the present studies were conducted in a greenhouse (GH) to ascertain the water stress-tolerant traits of maize and at the field level in the tropical environment of Thailand to see the stimulating possibility of the ascertained traits in a locally popular cultivar using ethephon. Depending on tolerance level, three maize genotypes (Suwan 2301 > Suwan 4452 > S 7328) were tested under different water conditions-well-watered, short-term, and long-term water stress-in the GH. At the field level, the locally popular maize cultivar Suwan 5819 was examined with six ethephon levels (doses in g a.i. ha-1 of ethephon, i.e., T1, 281 at V6 stage; T2, 281 at V6 + 281 at V10 stage; T3, 281 at V10 stage; T4, 562 at V6 stage; T5, 562 at V6 + 562 at V10 stage; T6, 562 at V10 stage) against no ethephon application (T0) under rainfed conditions. Maize suffered from the scarcity of sufficient rainfall during 26-39 days after planting (DAP) and 43-63 DAP in the field. The yield index (YI) was identified from biplot analysis as one of the suitable standards for drought tolerance checks for maize at GH as well as at field level in the tropics. The YI value of observed agro-physio-biochemical traits of maize in GH showed that relative water content (RWC, 1.23), stem base diameter (SBD, 1.21), total soluble sugar (TSS, 1.15), proline (Pr, 1.13), aboveground plant biomass (APB, 1.13), root weight (RW, 1.13), relative growth rate (RGR, 1.15), specific leaf weight (SLW, 1.12), and net assimilation rate (NAR, 1.08) were the most desirable. Efforts were made to stimulate these traits under water stress at the field level. Ethephon application as T1 helped to gain higher kernel yield (KY) (5.26 t ha-1) with the support of higher RWC (90.38%), proline (24.79 µmol g-1 FW), TSS (1629 mg g-1 FW), SBD (24.49 mm), APB (271.34 g plant-1), SLW (51.71 g m-2), RGR (25.26 mg plant-1 day-1), and NAR (0.91 mg cm-2 day-1) compared to others, especially no ethephon application. Furthermore, the attributes SLW, SBD, Pr, heat utilization efficiency (HUE), 100-kernel weight, TSS, electrolyte leakage, and lodging percentage showed a substantial direct effect and significant correlation with KY. Aside from higher KY, ethephon application as T1 tactics resulted in higher values of energy efficiency (1.66), HUE (2.99 kg ha-1 °C days-1), gross margin (682.02 USD ha-1), MBCR (3.32), and C absorption (6.19 t C ha-1), indicating that this practice may be a good option for maize sustainable production under rainfed conditions.