Search Results (34)

Masting, or the synchronous and intermittent production of seeds, can have profound consequences for Tropical Montane Cloud Forest (TMCF) tree populations and the trophic webs that depend on their mass flowering and seeds. Over the past 80 years, the importance of Fagus mexicana Martínez (Mexican beech) masting has become apparent in terms of conservation and management, promoting regeneration, and conserving endangered tree species, as well as the conscientious development of edible beechnuts as a non-timber forest product. The establishment of the relict-endemic Mexican beech is unknown, and several microenvironmental factors could influence natural regeneration. Thus, this study was conducted in two well-preserved Mexican beech forests to assess the influence of light incidence and soil moisture on the natural germination and seedling establishment of beeches. During two masting years (2017 and 2024), we assessed in situ beechnut germination and establishment. We tested the effect of the microenvironment of the oldest beeches on beechnut germination and seedling establishment. Our study highlights the complexity of the microenvironment of old beeches influencing the early stages of establishment and provides insights into possible conservation actions aimed at mitigating the impact of environmental change and humans. Full article

We report a landscape-scale natural experiment that followed the abundance and demography of forest-floor small mammals and the activity of small mustelids over a 4-year period of an extreme heat wave and abundant coniferous cone crops. Deer mice (Peromyscus maniculatus) and southern red-backed voles (Myodes gapperi) are major species in the coniferous forest-floor small mammal community near Summerland in southern British Columbia, Canada. Their major mammalian predators include the short-tailed weasel (Mustela richardsonii), long-tailed weasel (Neogale frenata), and American marten (Martes americana). We evaluated three hypotheses (H) that may explain the changes in these mammals from 2021 to 2024: (H₁) that large coniferous cone crops in 2022 would have generated high populations of forest-floor small mammals in 2023 owing to enhanced reproductive output and overwinter survival; (H₂) that increased activity of mustelids would have followed population increases, resulting in the decline of small mammal prey in 2024; and (H₃) that the widespread occurrence of cone crops in 2022 would also have elicited the same mammalian responses in 2023 at a second study area (Golden, BC) 276 km and three mountain ranges from Summerland. During the summer periods of each year, small mammal populations were monitored by intensive live-trapping, and mustelid presence was measured via an index of activity based on live traps, fecal scats, and predation events. The mean abundance and reproductive performance of the P. maniculatus and M. gapperi populations increased in response to the coniferous seedfall, thereby supporting H₁. The activity of small mustelids responded positively to increased numbers of small mammal prey and potentially acted in a regulatory and top–down function in these communities, and hence partially support H₂. Similar responses at Summerland and Golden indicated that this seedfall event and changes in the mammalian community occurred at a landscape-scale, thereby providing partial support for H₃. Potential differential effects of large seed crops on consumers did not affect the mean abundance patterns for P. maniculatus but apparently reduced this metric for M. gapperi. Heat waves, induced by anthropogenic climate change, may alter the frequency of coniferous masting events, and their effects may temporarily change the number and species of mammalian seed consumers and their predators. Full article

The sexual reproduction of Sasa borealis, a species of dwarf bamboo, occurred in central Japan from 2016 to 2017. S. borealis grows on the forest floor and serves as an important source of habitat and food for various animals. Sexual reproduction occurs in synchrony among individuals in a given area, leading to a decline in population and causing substantial disturbances to the forest ecosystem; however, the subsequent regeneration process remains unclear. In this study, we investigated S. borealis seedling regeneration over six years. Fixed plots were established in the forest in the year following the sexual reproductive event, and the growth of seedlings was monitored from seed emergence to seedling growth at the individual level. We considered biotic and abiotic factors to evaluate their influence on regeneration. We examined mammalian and arthropod foraging as biotic factors. Conversely, abiotic factors included temperature and humidity near the ground surface, solar radiation, soil conditions, and snow cover. Seedling growth was characterized by a slow rate and affected by morphological changes resulting from foraging and abiotic factors. The return of S. borealis to its presexual reproductive stage requires an extended duration. Our study provides precious information for future S. borealis conservation and management strategies. Full article

Seed orchards play important roles in supplying good seeds. Miniature orchards have the advantages of reducing management areas, but rapid crown development will decrease light intensity and seed production. Block-rotation cycles within an orchard need to be evaluated to optimize total seed production per unit time and area. The development of tree height and primary branches, as well as spatial light variation over the years after pruning and defoliation manipulation were evaluated in a miniature orchard of Chamaecyparis obtusa (Sieb. et Zucc.) Endl. set on the Pacific side of Japan. Just two years after manipulation, the branches of the upper-crown parts had grown so long that they were touching each other, and the light environments of the lower-crown parts had become drastically darker. Next, based on the crown development and light variation and the relationship between cone production and light intensity, we performed a simulation of total cone production over the years in a hypothetical orchard composed of multiple blocks. Then, the simulated total cone production was compared between the block-rotation cycles, where crown management was performed every three or four years. Compared to the three-year block rotation, the distribution of within-tree cone production for the four-year block rotation was more biased towards only the upper crown, since the lower crown became suddenly darker. It was estimated that cone production for the entire tree and the entire seed orchard would be lower than in the three-year block rotation. The approach and findings of this study will be useful for improving seed orchard management. Full article

The rising global energy demand, alongside concerns regarding environmental deterioration due to the use of fossil fuels, has spurred extensive investigation into renewable energy alternatives. Biomass-derived biodiesel, especially from lesser-known oil sources, emerges as a promising option. This research focuses on analyzing the fatty acid methyl esters (FAMEs) derived from Kariya (Hildegardia barteri (Mast.) Kosterm) seed oil through basic catalytic transesterification using gas chromatography–flame ionization detector (GC–FID) analysis, assessing its potential as a biodiesel feedstock. Oil extraction from Kariya seeds was carried out using three solvents (n-hexane, ethanol, and a 1:1 blend of hexane and ethanol), followed by transesterification with methanol. Gas chromatography–mass spectrometry (GC–MS) and GC–FID analyses were utilized to identify and quantify FAMEs in the resulting biodiesel. The results revealed various FAMEs, including methyl myristate, methyl palmitate, methyl stearate, methyl oleate, methyl linoleate, and methyl linolenate. Significant differences in FAME composition were observed among the samples, with hexane–ethanol Kariya oil biodiesel (HE-KOB) showing the highest FAME content (76.1%). This combination of solvents exhibited synergistic effects on the composition of HE-KOB, suggesting potential optimization strategies for biodiesel production. Fourier transform infrared spectroscopy (FTIR) provided additional insights into the molecular composition of the biodiesel samples, confirming their biodiesel nature through the identified functional groups such as methyl, methylene, hydrocarbon, ester, aldehyde, and alkene. Thermogravimetric analysis (TGA) for thermal decomposition also gave an insight into FAME composition and its contribution to the degree of conversion of biodiesel to energy. These findings highlight the feasibility of utilizing Kariya seed oil as a biodiesel feedstock, emphasizing the importance of solvent selection and transesterification conditions in optimizing FAME yield and composition. This research contributes to the exploration of underutilized oil sources for sustainable biodiesel production, aligning with the global shift towards cleaner and renewable energy sources. Full article

This study focuses on the natural regeneration of Nothofagus glauca, a critical component of temperate forests in the Mediterranean region of the Southern Hemisphere in Chile. Various harvesting and canopy opening methods were evaluated to understand their impact on the regeneration of this species. A “mast seeding” behavior was observed in seed production, with alternating years of high and low production. Seed viability was affected by lepidopteran infestation and extreme weather events. The results indicate variable seed quantity and quality, influencing regeneration. First-year seedling mortality was significant, reaching up to 95%, and regeneration decreased annually. Additionally, changes in canopy opening and solar radiation transmission were analyzed, revealing significant post-harvest modifications. This study provides valuable insights for the sustainable management of Mediterranean forests, emphasizing the importance of considering seed production variability and regeneration dynamics in decision-making processes. Full article

Immune responses to tissue-engineered grafts made of xenogeneic materials remain poorly studied. The scope of current investigations is limited by the lack of information on orthotopically implanted grafts. A deeper understanding of these processes is of great importance since innovative surgical approaches include the implantation of xenogeneic decellularized scaffolds seeded by cells. The purpose of our work is to study the immunological features of tracheal repair during the implantation of tissue-engineered constructs based on human xenogeneic scaffolds modified via laser radiation in rabbits. The samples were stained with hematoxylin and Safranin O, and they were immunostained with antibodies against tryptase, collagen II, vimentin, and CD34. Immunological and inflammatory responses were studied by counting immune cells and evaluating blood vessels and collagen. Leukocyte-based inflammation prevailed during the implantation of decellularized unseeded scaffolds; meanwhile, plasma cells were significantly more abundant in tissue-engineered constructs. Mast cells were insignificantly more abundant in tissue-engineered construct samples. Conclusions: The seeding of decellularized xenogeneic cartilage with chondrocytes resulted in a change in immunological reactions upon implantation, and it was associated with plasma cell infiltration. Tissue-engineered grafts widely differed in design, including the type of used cells. The question of immunological response depending on the tissue-engineered graft composition requires further investigation. Full article

The natural regeneration of the temperate oak forests is often insufficient. Acorns of the oak serve as the basis of the recruitment and key food resources in these ecosystems, thus the crop size, the germination success and seed predators have crucial roles in the process. Wild boar (Sus scrofa) is often considered as one of the main mitigating agents in oak regeneration. Therefore, in our study we analyzed and compared the spatial patterns of the acorn density and the patches rooted by wild boar within and among the different examined time intervals in a 28 ha Turkey-sessile oak (Quercus cerris, Q. petraea) forest stand. Data were collected between 2016 October and 2019 December. In the acorn density patterns, intra-annual similarities were recognized mainly, regardless of the crop size. Meanwhile, rooting patterns showed inter- and intra-annual similarities in mast years and intra-annual overlaps in non-mast years, indicating that masting is a fundamental driver of wild boar foraging behavior. However, a direct local connection between the rooting intensity and the acorn density could not be shown, as wild boars never fully depleted the acorns, even in intensively used patches. This study can help in predicting the intensively rooted forest patches, providing opportunities to manage wildlife conflicts. Full article

The American beech (Fagus grandifolia Ehrh.) has been impacted by the beech bark disease (BBD) complex throughout the northeastern United States for over 100 years, but the disease has been present in the Great Lakes region only for around 20 years, requiring acknowledgement of the evolving context surrounding F. grandifolia. This disease threatens to remove a foundational tree species which is especially important ecologically for wildlife habitat and mast, and as a climax successional species. We review advances in propagation techniques of F. grandifolia with the goal of addressing their use in the rehabilitative restoration of forests affected by BBD. Natural regeneration and artificial methods of propagation are addressed, along with how they may be applied for mitigation. Silvicultural interventions are discussed that may be necessary to protect and release resistant seedlings to promote persistence. An existing framework is used to explore context necessary for decision making in restoration. Nucleated seed orchards of resistant trees may currently be the most effective and practical method for introduction of BBD-resistant F. grandifolia into affected northern hardwood forests. Full article

Blackbrush (Coleogyne ramosissima Torr.) is the dominant shrub on three million hectares across the transition zone between the western North American warm and cold deserts. This paper presents a study of blackbrush population structure at the stand level at sixteen sites across the species range. New stand-level information is then integrated with what is already known about blackbrush population ecology to explore the stand-level consequences of several unusual features of blackbrush life history, including its masting reproductive strategy, its interactions with heteromyid rodents that are both seed predators and dispersers, and its ability to form ‘seedling banks’ of growth-suppressed individuals, often within the crowns of adult conspecifics. It complements earlier work showing that blackbrush stands are organized at both the inter-clump and intra-clump levels. Each clump represents an establishment nexus where younger individual genets replace older genets over an extended time period. Inter-clump structure is thus determined by the rate of establishment of new clumps rather than new individuals. This has resulted in contrasting stand structures in response to rodent community composition, disturbance regimes, and climatic variability at the leading and trailing edges of current blackbrush distribution in the eastern Mojave Desert and Colorado Plateau regions. Because blackbrush likely disperses too slowly to track anthropogenic climate change, assisted migration with wild-collected seeds may be necessary to promote its continued survival and dominance. Full article

Sporadic cone (or seed) production challenges longleaf pine forest restoration. Characterizing annual cone production change from long-term monitored data provides functional information on the foundational species of this imperiled ecosystem. In this study, permutation entropy (PE) and phase change were used to analyze longleaf pine annual cone production based on cone counts from four sites (Escambia Experimental Forest, Blackwater River State Forest, The Jones Center at Ichauway, and Sandhills State Forest). PE is an analytical tool to measure the complexity of a dynamic system while phase change characterizes the stage of self-organization. Results indicate that PE at each site was close to 1.0 (largely random changes in annual cone production) and generally increased with time. The positive association between the permutation entropy of cone production and average air temperature at different times was significant at two sites (Blackwater River State Forest and The Jones Center at Ichauway). The frequency distribution of phases (e.g., Poor (P), Fair (F), Good (G), Bumper (B)) in cone production followed negative power laws. Phase P could transition to any stage, but more than 50% remained in P across sites. For phase G, it would revert to P more than 50% of the time. Phase B would shift to P, except at Sandhills State Forest. The average lasting time of phase P was approximately 3.7 years. The overall relationship between the interval time of phase B and cone production was not statistically significant. Similarly, the overall relationship between cone production in phase B and the phase change times between consecutive B phases was not statistically significant. These results provide information on the ecological complexity of cone (or seed) production. Our methods can be helpful for estimating the occurrence of bumper cone (or seed) production, the lasting period between phase changes, and providing a tool for predicting natural regeneration potential over time for longleaf pine and other tree species (e.g., masting species). Full article

The seed predator Argyresthia conjugella Zeller has rowan as its preferred host plant. In years of poor fruiting in rowan, it oviposits on apples. To improve the knowledge of this apple pest, rowanberries were collected from localities all over Norway from 1971 to 1985, and seed predators and their parasitoids were allowed to emerge for up to five years. Two species of seed predators, A. conjugella and Megastimus brevicaudis Ratzeburg, and seven species of parasitic Hymenoptera were common. The distribution of these species is shown on EIS (European Invertebrate Survey) maps of Norway. The biology of the parasitoids is summarized based on the published literature and their behavior during emergence. The tendency for delayed emergence, which is an indication of prolonged diapause, was more pronounced in M. brevicaudis than in A. conjugella, the former appearing in all five years. Five of the parasitoids also delayed their emergence, and three of them to a high degree, up to five years. Prolonged diapause must be taken into account in studies of rowanberry insect guilds. Full article

Sympatric animals with similar requirements can separate their ecological niches along the microhabitat, food and time axes. There may be alternative reasons for an interspecific different activity pattern, such as intraspecific social constraints, predator avoidance or physical conditions such as temperature, precipitation and illumination. We investigated the importance of intraguild competition in a 2-year study in an inner-alpine mixed forest, using small forest rodents as our model species. Apodemus mice were the physically superior, and bank voles, Clethrionomys glareolus, the inferior competitor. We predicted that bank voles would exhibit increased diurnal activity when frequencies of the almost exclusively nocturnal Apodemus mice were high during a seed mast year. To investigate this, we recorded 19,138 1 min videos. Controlling for confounding variables, bank vole diurnal activity was significantly related to the frequency of Apodemus mice. We assume that at high densities of Apodemus mice, a purely nocturnal separation in the niche dimensions of time, habitat and microhabitat is no longer sufficient, and therefore an inverse activity pattern by the bank voles is reinforced. Our videos showed, however, that this does not require persistent aggressive meetings and we explain this by the long co-evolution of the taxa under study. Full article

The reported association of Moringa oleifera seeds and allergic disease clinically resembling occupational asthma in cosmetic manufacturing workers has resultedin the need to identify such components in the manufacturing process. However, Moringa oleifera leaves from the same plant, an important food ingredient, have limited immunotoxicity data. This study aimed to determine if Moringa oleifera leafproteins (MLP) can elicit allergic responses in BALB/c mice. The BALB/c mice were sensitized twice and challenged 10 times to evaluate the potential allergenicityof MLP in vivo. The results showed increased levels of mast cells, total and specific IgE and IgG, severe signs of systemic anaphylaxis, and reduced body temperature compared with controls. The sensitized mice serum observed enhanced levels of histamine and Th-related cytokine release. Compared with the control group, increased levels of interleukins IL-4, IL-9, and IL-17A and enhanced expression and secretion of normal T cells were found in the culture supernatant of splenocytes treated with MLP.This study suggeststhat MLPcanelicit allergic responses; this providesmore comprehensive guidance for identifying new allergen candidates and developing hypoallergenic MLP products. Full article

Mast cells are evolutionarily old cells and the principal effectors in allergic responses and inflammation. They are seeded from the yolk sac during embryogenesis or are derived from hematopoietic progenitors and are therefore related to other leukocyte subsets, even though they form a separate clade in the hematopoietic system. Herein, we systematically bundle information from several recent high-throughput endeavors, especially those comparing MCs with other cell types, and combine such information with knowledge on the genes’ functions to reveal groups of neuronal markers specifically expressed by MCs. We focus on recent advances made regarding human tissue MCs, but also refer to studies in mice. In broad terms, genes hyper-expressed in MCs, but largely inactive in other myelocytes, can be classified into subcategories such as traffic/lysosomes (MLPH and RAB27B), the dopamine system (MAOB, DRD2, SLC6A3, and SLC18A2), Ca²⁺-related entities (CALB2), adhesion molecules (L1CAM and NTM) and, as an overall principle, the transcription factors and modulators of transcriptional activity (LMO4, PBX1, MEIS2, and EHMT2). Their function in MCs is generally unknown but may tentatively be deduced by comparison with other systems. MCs share functions with the nervous system, as they express typical neurotransmitters (histamine and serotonin) and a degranulation machinery that shares features with the neuronal apparatus at the synapse. Therefore, selective overlaps are plausible, and they further highlight the uniqueness of MCs within the myeloid system, as well as when compared with basophils. Apart from investigating their functional implications in MCs, a key question is whether their expression in the lineage is due to the specific reactivation of genes normally silenced in leukocytes or whether the genes are not switched off during mastocytic development from early progenitors. Full article