Sphagnum Research Articles

Environmental impact of peat alternatives in growing media for European mushroom production.

Button mushrooms are an important protein source with a production of >48 million metric tonnes in 2021. Several life cycle assessments (LCAs) have been employed in assessing mushroom cultivation. This paper assessed potential impacts of relevant alternatives (sphagnum moss, grass fibres, spent casing and bark) to peat as casing materials for mushroom production across Europe by using LCA using a cradle to farm gate approach. Here, we: i) compared the environmental impacts of mushroom produced with different growing media across Europe ii) identified environmental hotspots across the value chains of mushroom growing media and iii) provide insights on the sustainability of mushroom growing media production. Two functional units have been used the kg and € of harvested mushrooms. Data were gathered from mushroom producers and casing processors across Europe. Changes in casing material for mushroom production caused environmental trade-offs, by reducing the resource use for fossil and by moderately changing (<7.7%) all other impacts assessed here except the bark used as casing material which caused a reduction for all impact categories. Thus, each of the casing alternative material could substitute peat in mushroom production with limited environmental impacts if productivity does not decrease. LCA demonstrated advantages or disadvantages of replacing part of the peat casings by other alternatives (e.g., sphagnum moss, spent casing, grass fibre, bark). As switching to alternatives becomes more urgent in the near future, potential trade-offs, advantages and disadvantages of using less peat need to be identified using a broader range of alternatives.

Impacts of different intensities of commercial Sphagnum moss extraction on CO2 fluxes in a northern Patagonia peatland.

Peatlands are key ecosystems for global climate regulation because they provide the most efficient carbon sink on the planet. Despite this, they have been widely degraded by various anthropogenic disturbances, causing imbalances in their ecological functioning. A more recent type of disturbance corresponds to the commercial extraction of Sphagnum mosses, which has been carried out in temperate peatlands distributed in Australasia and Patagonia. In the extreme north of Chilean Patagonia, many peatlands have been subject to intensive commercial extraction of the moss Sphagnum magellanicum, causing their degradation and impacts on CO2 fluxes, a situation that has been barely studied. We conducted a field study on CO2 exchange at three sites, two of them representing different intensities of commercial extraction of the moss S. magellanicum and an undisturbed site in an anthropogenic peatland located in the northern Patagonian region of Chile. CO2 fluxes were measured in situ using a transparent and opaque closed chamber. Gross primary productivity (GPP), ecosystem respiration (Reco), and net ecosystem exchange (NEE) were modeled at high temporal resolution by determining daily and cumulative CO2 flux rates during the vegetation growing season. The NEE records showed significant differences between the three sites studied, attributed to differences in the GPP. Sites with high (<30% residual moss cover) and low (∼50% residual moss cover) extraction intensity were a source of CO2, with cumulative NEE values of 416.6±13.1 and 248.2±9.9g CO2-C m-2 season-1 respectively, while the undisturbed area was a moderate CO2 sink with a cumulative NEE of -86.4±2.8g CO2-C m-2 season-1. Our results provide evidence that increasing levels of Sphagnum moss commercial extraction generate increases in CO2 emissions from anthropogenic peatlands into the atmosphere, and could be used to advance the improvement of current regulations that regulate moss harvesting in Chile.

Evaluation of bromelia karatas as a bioindicator of lead contamination

Abstract: metals toxic contamination is a problem that has increased mainly due to anthropogenic activities. Lead (Pb) is a hightly toxic metal present in the environment due to industrial activities, such as mining, smelting, manufacturing, and burning of fossil fuels. This work studied Bromelia karatas as a bioindicator of the quality of the environment in the presence of lead. Forty 200-day-old plants (Bromelia karatas) were used, of which 30 were transplanted in a substrate (Peat moss) contaminated with Pb, using Pb(NO3)2 as a contaminating agent, at different concentrations, T1= 1000, T2=2000 and T3=3000 mg/kg (milligram of Pb/Kilogram of substrate), and 10 were used as control (Tc). At the end of the experiment, the presence of Pb was analyzed and found in the plant tissues (leaves and roots), using the ICP-OES equipment. This research revealed the potential of Bromelia karatas as a bioindicator of Pb contamination in soil, causing visible symptoms of foliar damage on its leaves with high doses of the contaminant. The low cost, easy reproduction and portability of bromeliad compared to other bioindicators make it a better option to be used as a bioindicator and/or biomonitor.

Bioinspired hydrophobic pseudo-hydrogel for programmable shape-morphing

Inspired by counterintuitive water “swelling” ability of the hydrophobic moss of the genus Sphagnum (Peat moss), we prepared a hydrophobic pseudo-hydrogel (HPH), composed of a pure hydrophobic silicone elastomer with a tailored porous structure. In contrast to conventional hydrogels, HPH achieves absorption-induced volume expansion through surface tension induced elastocapillarity, presenting an unexpected absorption-induced volume expansion capability in hydrophobic matrices. We adopt a theoretical framework elucidating the interplay of surface tension induced elastocapillarity, providing insights into the absorption-induced volume expansion behavior. By systematically programming the pore structure, we demonstrate tunable, anisotropic, and programmable absorption-induced expansion. This leads to dedicated self-shaping transformations. Incorporating magnetic particles, we engineer HPH-based soft robots capable of swimming, rolling, and walking. This study demonstrates a unusual approach to achieve water-responsive behavior in hydrophobic materials, expanding the possibilities for programmable shape-morphing in soft materials and soft robotic applications.

DEVELOPING A COST-EFFECTIVE MICROPREDATION PROTOCOL FOR TWO CARNATION (DIANTHUS CARYOPHYLLUS L.) VARIETIES UNDER IN VITRO CONDITIONS

A successful attempt was made through this investigation to develop a cost-effective protocol for two varieties of carnation (Dianthus caryophyllus L.) ornamental plants named Clove Pink and Scarlet. Healthy and vigorous cultures were established by inoculating axillary buds on MS medium after a successful disinfestation process by sterilizing in 2.5% NaOCl for 10 minutes. The microshoots were multiplied by testing different benzyladenine (BA) and kinetin concentrations. Luckily, the best multiplication parameters were achieved with MS medium free of growth regulators, which will reduce the propagation costs. The higher number of shoots (11.60 shoots/ explant), leaves (59.80 leaves/ explant), and longest shoots (10.90 cm) when grown on MS medium without Plant growth regulators (PGRs), Additionally, the clove pink variety on MS medium with 1.5 mg l-1 BA and Scarlet variety grown on MS-free of PGRs respectively. A 100% percent rooting was achieved for both varieties when 1.5 mg l-1 Naphthalene acetic acid (NAA) was added to the culture media. The same NAA concentration for scarlet variety microshoots resulted in the highest number of roots (26.2 roots/explant) and the longest roots (9.0 cm). Successful acclimatization was observed by transferring the well-rooted plantlets to greenhouse conditions while putting them in peat moss

The Anti‐Inflammatory Activities of Sphagnum palustre L. Ethanol Extract to Control Inflammation in RAW264.7 Cells

ABSTRACTDiscomfort caused by inflammation leads to stress and anxiety in patients and seriously decreases the patients' quality of life. People prefer to use natural products instead of anti‐inflammatory drugs because of their low toxicity and side effects. Studies have shown that Sphagnum palustre L. (S. palustre) can be used as medicinal plant, but few studies have focused on its anti‐inflammatory effects. This study explored the mechanism of action of the ethanol extract of the peat moss plant S. palustre on lipopolysaccharide‐induced inflammation in macrophage RAW264.7 cells. Components in S. palustre ethanol extracts (SPE) were identified by HPLC‐MS, which mainly included 4‐methoxybenzaldehyde, 4‐methoxycinnamaldehyde and oleanolic acid. The effects of different concentrations (6.25–100 μg/mL) of SPE after 24 h administration were evaluated to establish a cellular inflammation model. Three biological replicates were performed based on each experiment, the MTT assay results showed that a low concentration of SPE promoted cell proliferation marked by Formazan. In a neutral red uptake assay, the SPE group was effectively inhibited the cell phagocytosis rate. With the increase of SPE concentration, intracellular ROS release decreased, which detected by DCFH‐DA. Immunofluorescence assay result showed that SPE inhibited the release of reactive oxygen species from macrophages with fluorescent markers and DAPI. SPE inhibited the release of nitric oxide from macrophages as well. What's more, SPE significantly decreased the protein expression of interleukin (IL)‐1, IL‐6, and nuclear factor (NF)‐κB according to enzyme‐linked immunosorbent and immunocytochemical assays. SPE reduces inflammation in macrophage RAW264.7 cells and thus is a promising natural anti‐inflammatory plant.

Investigation of the Effects of Rooting Medium and IBA Concentration on Rooting and Shoot Development of Bougainvillea (Bougainvillea spp.) Cuttings

In this study, the effect of different rooting mediums (peat moss, peat + sand, peat + loam) and IBA (indole-3-butyric acid) concentration was investigated on hardwood cuttings taken from Bougainvillea glabra, Bougainvillea spectabilis, and Bougainvillea x buttiana species. The cuttings were treated with 0, 1000, 2000 and 3000 mg/l IBA. Statistical evaluation was performed according to a randomized block experimental design with three factors and three repetitions. The results showed that Bougainvillea x buttiana cuttings had the highest number of roots, root fresh weight, longest shoot length, and shoot fresh weight. Cuttings grown in 100% peat medium had the highest rooting percentage, root number, root dry weight, leaf number, and shoot fresh weight. Regarding IBA concentrations, the cuttings treated with 3000 ppm IBA had the highest number of roots, root length, and root fresh weight. Furthermore, in all of the Bougainvillea species, the highest rooting percentage and leaf number were observed in cuttings treated with 2000 ppm IBA. Notably, Bougainvillea x buttiana cuttings treated with 1000 ppm IBA dose and planted in peat medium provided the longest shoot length, highest shoot fresh weight, and shoot dry weight. In conclusion, the findings show that the growing medium has a statistically significant effect on the rooting and root quality of cuttings and that it would be useful to investigate various rooting hormones, dasages and rooting media to increase rooting and shoot development. Considering growing medium plays a crucial role in plant growth, it can be stated that further improvements in rooting and growth can be realized via utilizing the enhanced physical and chemical properties of peat-based mixtures.

Balancing the solar irradiance needs: optimising growth in sphagnum palustre through tailored UV-B effects

BackgroundThe carbon sequestration potential and water retention capacity of peatlands are closely linked to the growth dynamics of Sphagnum mosses. However, few studies have focused on the response of Sphagnum moss growth dynamics to UV-B radiation, and existing research has emphasized species differences. In this study, Sphagnum palustre L., a dominant species in the peatlands of Southern China, was selected as a research subject, and its response to UV-B radiation has not been reported before.ResultsIn the field, the morphology and growth differences of Sphagnum palustre under microhabitats with varying UV-B radiation intensities were monitored. Our findings revealed that the height of Sphagnum palustre increased the most in the microhabitats (Juncus community) with the weakest UV-B radiation, however the capitate branch area and biomass of Sphagnum palustre were highest under the Fern community, where UV-B radiation was attenuated by 50% during the summer. In the laboratory, we established four levels of UV-B radiation treatments: 0 MJ/m2/d (control group, no UV-B radiation), 0.2 MJ/m2/d (low UV-B radiation), 0.4 MJ/m2/d (middle UV-B radiation), and 0.8 MJ/m2/d (high UV-B radiation). We investigated the effects of UV-B radiation intensity on the morphology, biomass, and water-holding capacity of Sphagnum palustre after exposing it to UV-B radiation for 30 days. Results indicated that low UV-B radiation (0.2 MJ/m2/d) significantly enhanced the growth of Sphagnum palustre. The capitulum area, plant height, capitulum biomass, and individual biomass of Sphagnum palustre increased by 14.60%, 1.27%, 10.98%, and 16.49%, respectively, compared to the control. Additionally, the maximum water absorption rate of Sphagnum palustre reached 4515.44%. In contrast, under high UV-B radiation (0.8 MJ/m²/d), these indicators significantly decreased, while the water loss rate significantly increased.ConclusionThis study suggests that the intensity of UV-B radiation can be artificially regulated to optimize the growth of Sphagnum, accelerate peatland restoration, and enhance the yield of artificially cultivated Sphagnum moss.

Optimization of Compost and Peat Mixture Ratios for Production of Pepper Seedlings.

Substituting peat moss with compost derived from organic waste in plant nurseries presents a promising solution for reducing environmental impact, improving waste management, and enhancing soil health while promoting sustainable agricultural practices. However, selecting the appropriate proportions of both materials is crucial for each plant species. This study investigates the effects of different ratios of compost and peat mixtures on the growth and development of pepper seedlings. The compost mixtures used in the study included the following combinations: sewage sludge with sawdust (A), sewage sludge with sawdust and biodegradable garden/park waste (B), and biodegradable garden/park waste with sawdust (C). The final substrates used for seedling production were composed of composts (A, B, C) and peat (O) as a structural additive, mixed in different proportions by mass: I-O 25%, II-O 50%, and III-O 75%. Seedlings grown in these substrates were assessed using biometric and physiological measurements. Nematode species present in substrates were identified by metabarcoding analysis. The results revealed that substrate productivity depended not only on nutrient content but also on structural properties, which were significantly influenced by the peat proportion. Among the tested compost mixtures, variant A I emerged as the most effective substrate, promoting optimal seedling growth. Molecular nematode analysis revealed significant nematode contamination in substrates with higher peat proportions (C II and C III), including Meloidogyne sp. Lichtenburg (26%), Meloidogyne hispanica (5%), Meloidogyne sp. Mi_c1 (3%), Meloidogyne ethiopica (2%), and Meloidogyne thailandica (1%). The findings underscore the critical importance of achieving an optimal balance between nutrient content and structural properties in substrates to support the healthy growth and development of pepper seedlings. To further enhance crop performance and reduce the risk of pest-related damage, it is essential to prioritize the improvement of substrate selection strategies. Monitoring for nematode contamination is crucial to prevent potential compromises in seedling quality and overall productivity.

Biochar reduces containerized pepper blight caused by Phytophthora Capsici

Phytophthora blight caused by Phytophthora capsici is a serious disease affecting a wide range of plants. Biochar as a soil amendment could partially replace peat moss and has the potential to suppress plant diseases, but its effects on controlling phytophthora blight of container-grown peppers have less been explored, especially in combination of biological control using Trichoderma. In vitro (petri dish) and in vivo (greenhouse) studies were conducted to test sugarcane bagasse biochar (SBB) and mixed hardwood biochar (HB) controlling effects on pepper phytophthora blight disease with and without Trichoderma. Sugarcane bagasse biochar and HB were blended with the commercial substrate (CS, peat-based) at 10% (SBB10, by volume), and 10%, 30%, 50%, 70% (HB10, HB30, HB50, and HB70, by volume), respectively, and CS (CS100) was used as the control. Both in vitro and in vivo studies used randomized complete block design with three treatment factors: pathogen (without or with inoculation of P. capsici), biochar (different biochar treatments), and Trichoderma (without or with inoculation). In vitro results showed that Trichoderma inhibited P. capsici growth while biochar did not have significant beneficial effects. In vivo results showed that plants grown in HB30 and HB50 had similar or higher plant growth index and shoot dry weight than the control regardless of pathogen presence. In the presence of the pathogen, plants grown in HB30, HB50, and HB70 had significantly lower disease severity, and disease incidence ratings than the control, while Trichoderma did not show beneficial effects on controlling the disease. In conclusion, HB replacing 30% and 50% peat moss in substrate could reduce pepper blight disease caused by P. capsici without negatively affecting plant growth.

Checklist of oribatid mites (Acari: Oribatida) from peatlands in the United States with notes on oribatid mites from a bog in Minnesota

Peatlands are important ecosystems for carbon storage worldwide and often contain unique species. Oribatid mites are the dominant soil arthropods in terrestrial systems like peatlands, where they show high diversity, yet are under-sampled. To create a checklist of oribatid mite species from peatlands in the U.S., we collected a total of 53 peat-soil samples between 2015 and 2020 from a peatland located at the Marcell Experimental Forest in Minnesota, U.S. that yielded an assemblage of 27 families, 43 genera and 49 species; species richness estimates range between 56–102 species. We compiled a final checklist with data from previous studies of American peatlands available online up until July 2024 that revealed an additional 107 species for a total of 156 species distributed in 83 genera and 27 families known from peatlands in the U.S. From our samples, Punctoribates palustris is present in the most states (N=6), and is known to be associated with Sphagnum mosses in North America. Other common peatland species such as Eniochthonius mahunkai, Mainothrus badius and Limnozetes lustrum were also abundant at our site. However, we also found species typical of drier environments (e.g., dry forests, dry montane regions, canopy habitats) such as Eueremaeus nr. proximus, Scapheremaeus palustris, and Cepheus corae. Thus, our results reinforce the idea that peatlands may have a specific subset of species that are common to these ecosystems, but that in general many different species can be occasionally found in peatlands.

Estimation of active substances and compounds in orange seedlings Citrus aurantium L when spraying with nanofertilizers and humic acid

The experiment was conducted at the research station of the Faculty of Agriculture and Marsh of Thi Qar University during the growing season (2022-2022). Orange seedlings were obtained. Citrus aurantium, one year old, grown as uniformly as possible, from a nursery in Diyala governorate in 2022, and the seedlings were transplanted into 10 kg plastic pots (26 cm diameter) filled with a growing medium mixed with soil and peat moss. The plant care process was carried out in a similar manner throughout the study period, including pruning, weeding, fertilization and irrigation. The study was conducted as a two-factor factorial experiment using a randomized complete block design (R.C.B.D.). The first factor represented the spraying of composite nanofertilizer NPK at three concentrations (1, 0.5, 0) g.L-1, and the second factor represented the spraying of humus at three concentrations (0, 1, 2, ) g.L-1. The interval between one spraying and the next was 3 sprayings with an interval of two weeks. The results of the study can be summarized as follows: The spraying treatment of nanofertilizer NPK showed a positive effect on most of the active ingredients in bitter orange plants. The spray treatment with 100 mg L-1 concentration significantly outperformed the total sugar, naringenin, limonene, terpenes, and pyran compounds by 0.793%, 59.00%, 2.967%, 15.468%, and 7.954%, respectively. The average organic fertilizer spray treatment showed positive effects on most nutritional and chemical parameters of bitter orange seedlings. Citrus aurantium. The spray treatment with 2 g L-1 concentration had a better effect, with the highest proportions of total sugar, naringenin, limonene, terpenes, and pyran compounds, which were 0.760%, 55.28%, 2.772%, 15.086%, and 7.903%, respectively. The interaction coefficient between the two examined factors had a significant positive effect on most of the examined phytochemical and chemical properties. The interaction coefficient between 100 ml L-1 nano-NPK concentration and 2 g L-1 humus concentration recorded the best results for the active ingredient indicators such as naringenin, limonene, terpenes, and pyrans..

Effect of saline concentrations and humidity percentage on alfalfa va-rieties (Medicago sativa L.) from the Mexicali Valley, Mexico.

Objective: The aim of this experiment was to identify alfalfa varieties resistant to salt and drought stress in Mexicali Valley Mexico. Design/methodology/approach: Four alfalfa (M. sativa L.) varieties were used: Cuf-101 C, FD9, Pioneer and Cuf-101 P. Drought stress resistance was evaluated using four different percentages of commercial peat moss substrate (100%, 50%, 25%, and 15%), and saline stress resistance was evaluated by applying four concentrations of NaCl (0 mM, 50 mM, 100 mM, and 200 Mm.The variables evaluated in each treatment were: plant height, number of leaves and root length. The data obtained were subjected to an analysis of variance using the SAS statistical package version 9.0 with an α=0.5. Results: Alfalfa variety Cuf-101 had a good adaptation to both stresses with an average height of 11.28 cm and an average number of leaves of 3.54. Seed germination of alfalfa varieties (M. sativa L.) subjected to salt stress were affected even at the lowest NaCl concentration. Conclusions: The alfalfa variety with the highest germination percentage in all NaCl concentrations was Cuf-101 C with 91.17%.

Hydrophysical Properties of Peat in Undisturbed and Smelter‐Impacted Peatlands: Implications for Moss Recovery, Drought and Wildfire

ABSTRACTPeatlands are critical for global climate regulation storing approximately 500 Gt of carbon and accounting for 33% of global soil organic carbon. Regionally, these ecosystems provide essential wildfire resilience and are important pollutant sinks but degradation puts these key ecosystem services at risk. Smelting operations in Sudbury, ON, Canada, released approximately 12 000 t of particulate copper and nickel into the atmosphere between 1883 and 1969. Toxic metal and sulphur deposition on peatlands from smelting activities caused the widespread decline of keystone peatland moss species (i.e., Sphagnum) and altered peat properties. The changes in peat hydrophysical properties due to historical metal contamination likely reduce peatland resilience to drought and wildfires, thereby increasing the potential for toxic heavy metal remobilisation; however, these peat properties changes have yet to be quantified. We determine 1) how historical smelter pollution impacts peat hydrophysical properties by measuring bulk density, saturated hydraulic conductivity and soil water retention in the upper 40 cm of both undisturbed (located ~160 km outside the deposition region) and smelter‐impacted peatlands, 2) use these data to explore the vulnerability of these peatlands to wildfires and drought and 3) assess the potential for natural Sphagnum moss recovery. Smelter‐impacted peat had a significantly higher bulk density, lower macroporosity and saturated hydraulic conductivity that drove large differences in modelled soil water tension profiles during simulated drying events. These differences in soil water tension and retention profiles resulted in the smelter‐impacted peat having a far greater proportion of the peat profile that would be susceptible to smouldering combustion than the undisturbed peat. Additionally, the smelter‐impacted peat properties likely contributed to the limited Sphagnum moss recovery, while concurrently increasing drought and wildfire risk. As such, we argue that contaminated peatland restoration is necessary to enhance Sphagnum moss recovery to mitigate toxic metal remobilisation risk from drought and wildfire.

Carbon dioxide and methane gas exchange following sphagnum moss harvesting in boreal peatland

Understanding the impacts of Sphagnum moss harvesting on peatland carbon (C) balance is crucial due to its potential rise as an anthropogenic land use. We studied eight nutrient-poor peatlands in Finland, harvested between 2015 and 2021, focusing on net ecosystem exchange of CO2 (NEE) and methane (CH4) emissions. The greenhouse gas fluxes were measured to evaluate the sustainability of harvesting practices. Results showed significant variability in Sphagnum regeneration, with wet strip-harvested sites achieving 2–28% re-establishment in 2–8 years, while drier clear-harvested sites saw minimal spontaneous regeneration in 1–6 years. In addition to vegetation succession, GHG emissions were moisture dependent. In wet sites CH4 emissions increased along with time since harvesting and Eriophorum vaginatum (L.) cover, while dry sites exhibited overall lower CH4 fluxes. Younger (1–2 years post-harvest), dry sites were significant CO2 sources due to low photosynthetic activity. Older dry site with sparse ericoid shrub vegetation acted as CO2 sink. Wet sites initially had lower CO2 sink capacity, but this increased as E. vaginatum spread, and reached a plateau when Sphagnum mosses emerged, highlighting the importance of suitable water table levels for efficient CO2 sequestration.

Unlocking Molecular Fingerprint of an Ombrotrophic Peat Bog: Advanced Characterization Through Hexamethyldisilazane Thermochemolysis and Principal Component Analysis.

This study examines a boreal peatland (the Sagnes peatland, Fanay, Limousin, France) with a depth of 1 m. This peatland is currently in the late stages of organic deposition, as evidenced by the growth of Carex species, along with Sphagnum mosses, in the uppermost level. To gain molecular insights, we conducted an analysis of the lignin and polyphenolic counterparts using HMDS (hexamethyldisilazane) thermochemolysis, enabling the identification of lignin degradation proxies. The goal was to develop characteristic indicators for the state of lignin degradation based on the relative distribution of lignin phenols, measured by gas chromatography coupled with mass spectrometry (GC-MS) after the HMDS thermochemolysis. For that purpose, the singular contribution of the 11 aromatic moieties yielded, along with SGC (sum of lignin moieties) and the most lignin degradation proxies, were applied. It has been shown that HMDS thermochemolysis exhibited the capacity to reveal oxidized and degraded lignin fractions, following the increasing trend yielded for most moieties and SGC proxy, in the mesotelm and catotelm layers. In addition, the C/G (Cinnamyl/Guaiacyl) and S/G (Syringyl/Guaiacyl) ratios showed their highest input in the upper half of the core. This bias in the aforementioned ratios could indicate that HMDS thermochemolysis is to be applied for geological samples, where low G-compounds exist. For the sake of validating HMDS thermochemolysis' application, Principal Component Analysis (PCA) was then applied to the molecular fingerprint. For ratios and proxies of aromatic moieties of HMDS thermochemolysis, the PCA approach exhibited a higher contribution (79%). This indicates the efficiency of these ratios in describing the molecular fingerprint of peat depth records. In addition, a higher separation between the contributions of the investigated variables (molecular proxies) along the first two PCs was noticed. In other words, the variables that showed a high contribution towards PC1 exhibited a low contribution towards PC2, and vice versa. These findings indicate the high reliance of applying the ratios and proxies of HMDS thermochemolysis.

Photosynthetic Responses of Peat Moss (Sphagnum spp.) and Bog Cranberry (Vaccinium oxycoccos L.) to Spring Warming.

The rising global temperature makes understanding the impact of warming on plant physiology in critical ecosystems essential, as changes in plant physiology can either help mitigate or intensify climate change. The northern peatlands belong to the most important parts of the global carbon cycle. Therefore, knowledge of the ongoing and future climate change impacts on peatland vegetation photosynthesis is crucial for further refinement of peatland or global carbon cycle and vegetation models. As peat moss (Sphagnum spp.) and bog cranberry (Vaccinium oxycoccos L.) represent some of the most common plant functional groups of peatland vegetation, we examined the impact of experimental warming on the status of their photosynthetic apparatus during the early vegetation season. We also studied the differences in the winter to early spring transition of peat moss and bog cranberry photosynthetic activity. We have shown that peat moss starts photosynthetic activity earlier because it relies on light-dependent energy dissipation through the winter. However, bog cranberry needs a period of warmer temperature to reach full activity due to the sustained, non-regulated, heat dissipation during winter, as suggested by the doubling of photosystem II efficiency and 36% decrease in sustained heat dissipation between the mid-March and beginning of May. The experimental warming further enhanced the performance of photosystem II, indicated by a significant increase in the photosystem II performance index on an absorption basis due to warming. Therefore, our results suggest that bog cranberry can benefit more from early spring warming, as its activity is sped up more compared to peat moss. This will probably result in faster shrub encroachment of the peatlands in the warmer future. The vegetation and carbon models should take into account the results of this research to predict the peatland functions under changing climate conditions.

Threshold Behavior Hidden in the Growth Response of Peat Moss Sphagnum riparium to Temperature.

The balance between photosynthetic carbon accumulation and respiratory loss in plants varies depending on temperature. This leads to a situation where the increased need for carbon is not met when a certain temperature threshold is reached. Over the last two decades, temperature thresholds in carbon metabolism in autotrophic systems have been widely studied. However, it remains unclear how these thresholds manifest themselves in the natural growth of individual plant species. To address this issue, we used data from an extensive monitoring of the growth of peat moss Sphagnum riparium over 9 years in mires in Karelia (Russia). We measured the growth of shoots in sample plots and obtained 1609 estimates of growth rates during the monitoring period. Investigating the relationship between growth rate and temperature, we identified two distinct intervals in response to temperature. These two intervals are separated by the temperature threshold of 13.2 °C. The first interval, which covers 42% of the growing season, exhibits a strong exponential dependence of growth rate on temperature, with a coefficient Q10 = 4.01. This indicates that growth is most sensitive to changes in temperature within this range. In contrast, the second interval (58% of the growing season) shows a weaker dependence, with a Q10 coefficient of 1.21, suggesting that growth is less responsive to changes within this temperature range. The temperature threshold was found to be negatively related to May (r = -0.76; p = 0.018) and September (r = -0.78; p = 0.012) temperatures of the previous growing season, and together they best explain (r = -0.91; p = 0.0007) the temperature threshold. Overall, our findings suggest that the temperature threshold does exist in the growth of S. riparium and can be identified in different years. The negative correlation between temperature threshold and May and September temperatures from the previous year indicates that intervals in the growing season with temperatures near the temperature threshold have an impact on subsequent carbon balance and are particularly significant for the further growth and development of Sphagnum mosses.

Recovery of peat-forming layer after a fire on mesotrophic bog (Khabarovsk Territory)

The paper considers the structural organization of the peat active layer (acrotelm) of a mesotrophic bog in the Middle-Amur Lowland. Data on the phytomass and production of mosses as well as vascular plant roots are provided to describe the dynamics of the layer structure restoration after fire. It was established that the phytomass of live sphagnum mosses has recovered by 42% in 12 years after the fire, with a change in the dominating species. The production of dominant Sphagnum fuscum ((84 ± 14) g/m2) was 1.5 times more than the production of S. divinum ((54 ± 14) g/m2) before the fire, and than decreased by 1.5 times on the site that was unburned in 2008 and by 4 times in the burned site by the end of the observations. An analysis of the Polytrichum strictum phytomass dynamics during the pyrogenic succession of the phytocenose is provided. The phytomass of P. strictum in the 0–30 cm horizon rose by the end of the monitoring observations by (1537 ± 540) g/m2 on the burned site and by (2142 ± 366) g/m2 on the site not affected by the 2008 fire.

An Investigation into the Effects of Varying Seasons, Indole-3-Butyric Acid (IBA) and Rooting Media on the Rooting and Longevity of Air-layered Water Apples (Syzygium samarangense L.)

Background: The variation observed in sexual propagation often results in slow growth and fruit development, attributed partly to insufficient photosynthates during early growth stages. To address this challenge, vegetative propagation methods such as air layering offer promising solutions. This technique not only accelerates productivity but also enhances the quality of water apples. Recognizing the importance of air layering in water apple cultivation, this experiment was conducted to standardize this technique by examining the impact of different seasons and planting media in the western tropical wet and dry climate of Tamil Nadu. Methods: The study was conducted to evaluate the variables affecting air layering in water apples in Coimbatore district. The experiment was carried out with three different factors like seasons [August (S1), September (S2) and October (S3)] and IBA [applied at different concentrations of 2000 mg/L (I1), 3000 mg/L (I2) and 4000 mg/L (I3)] along with different rooting media: Cocopeat (M1) and Sphagnum moss (M2). The factorial randomized complete block design (FRCBD) was laid out for statistical analysis. Result: Sphagnum moss performed as a better rooting medium due to its high water holding capacity and good aeration. Increase in the number and early formation of roots were due to more rain fall and high relative humidity in August, that resulted in more nutrient uptake and structural stability. The discovery aids in determining the optimal conditions, including season, dosage and combination (4000 mg/L IBA with sphagnum moss applied in August), for successful air layering in water apple.