Filters
What factors affect the alpha diversity of microarthropods (Acari, Collembola) on King George Island (Antarctica)?
AbstractThe natural environment in polar regions is being transformed, glaciers are melting and succession of microarthropods is being observed. We tested the hypothesis that habitat conditions, determined by the locality and character of the vegetation cover, play a significant role in such succession. The material for analysis was collected from four localities on King George Island in Antarctica: Arctowski Station, Demay Refuge, Republica del Ecuador Refuge and Comandante Ferraz Antarctic Station. From each locality, 30 samples (grasses, lichens, mosses) were collected and 310 508 microarthropod specimens were recorded, with 17 species (1 Mesostigmata, 9 Oribatida, 7 Collembola species) identified. Based on statistical analyses, it was shown that microarthropod communities differ both in individual localities and selected microhabitats. The greatest number of species was reported in the grass turf, while the greatest number of individuals was recorded in mosses. The dominant species at all the localities was Cryptopygus antarcticus antarcticus (299 203 individuals), which was found in greatest numbers in grasses and mosses. In turn, Tullbergia mixta (2485 individuals) was the dominant species of the lichens. Moreover, the following species, new to King George Island, were also identified: Flagrosuctobelba subcornigera, Liochthonius australis, Membranoppia ventrolaminata and Quadroppia monstruosa belonging to Oribatida as well as Archisotoma brucei belonging to Collembola.
Application of functional analysis in dendrometry using five-year growth of selected dendrometric traits of scots pine Pinus sylvestris L.)
Abstract The differentiation between age classes of Scots pine (Pinus sylvestris L.) was analyzed with regard to the five-year increment of seven traits: height growth (zh5), diameter growth at breast height (zd5), cross-sectional area growth at breast height (zg5), volume growth (zv5), volume growth intensity coefficient (i5), and slenderness (s). Measurements were made in five periods for 24-year-old trees and six periods for 33-year-old trees, all growing in fresh mixed coniferous forest sites. Repeated measures data analysis was conducted separately for all traits. Multivariable functional data analysis (FDA) was proposed to compare age classes of trees. The functional variables which resulted from this analysis can be used, as data, in many analyses (designate functions representing each of trees, FPCA – functional principal component analysis, FLDC – discriminant analysis, permutation analysis of variance). The results of the above analyses revealed significant differences between age groups. Furthermore the functions and FPCA were used to detect outliers. This procedure had not previously been used for such a purpose. FPCA explained 55% of the total variance, with the first two components clearly separating the groups. The study showed that 33-year-old trees exhibit stable growth, while 24-year-old trees show greater variability, highlighting the impact of age on growth dynamics. Permutation analysis of variance confirmed significant growth differences between the groups. The findings highlight the importance of age as a factor influencing tree growth and demonstrate the effectiveness of the multivariable FDA approach for analyzing such data.
Evaluation of the Quality and Possible Use of a New Generation of Agricultural Nets for Packing Bulk Materials in Terms of the Aspect of Reducing the Environmental Burden
In modern agriculture, packaging materials are becoming an important means of production in the technologies for harvesting bulk materials. The agricultural net currently used for this purpose is usually made of HDPE—high-density polyethylene. The aim of the study was to evaluate the agricultural net produced in light technology under the commercial name of Covernet. Based on the tests conducted for nine variants of different models of round balers and different bulk materials collected by them, it can be concluded that, in each case, the net (Tama LT) wrapped the cylindrical bales well or very well. The mean elongation of COVERNET during bale wrapping was over 8% for the tested machines and harvested materials. The tests confirmed the usefulness of the new generation of agricultural nets (Tama LT) for wrapping various agricultural bulk materials of various humidities. There is an urgent need to develop and implement in practice a technology for recovering used agricultural nets and converting them into granules that can be used again in their production.
The Diversity of Arachnid Assemblages on the Endemic Tree Zelkova abelicea (Ulmaceae): An Evaluation of Fragmentation and Connectivity in Crete (Greece)
Zelkova abelicea is an endemic tree growing only on eight mountain stands on the Greek island of Crete. The aim of this study was to determine the structure of the assemblages and analyze the diversity of the arachnid assemblages living on Zelkova abelicea, an endemic tree species in Crete. Material for the analyses was collected from tree trunks, oftentimes covered by bryophytes or lichens. In the examined material, 85 taxa were recorded. The most numerous groups represented in the analyzed material were Acari, including representatives of the orders Mesostigmata (78 ind. of 18 spp.) and Oribatida (1056 ind. of 51 spp.). In the order Mesostigmata the species represented by the highest numbers of specimens were Onchodellus karawaiewi (15 individuals) and Hypoaspisella sp. (13), which is probably a species new to science. In turn, representatives of the order Oribatida were much more numerous, with Zygoribatula exilis (284) and Eremaeus tuberosus (210) being identified in the largest numbers. Among the eight sampled localities, Gerakari (646 ind. and 50 spp.) and Omalos (409 ind. and 43 spp., respectively) had by far the richest assemblages. Statistical analyses confirmed the highly diverse character of the arachnid assemblages at the individual sites, which is a consequence not only of the varied numbers of arachnids found, but also of the presence of very rare species, such as Androlaelaps shealsi, Cosmolaelaps lutegiensis or Hoploseius oblongus. These results highlight the high species diversity of the arachnids found on Z. abelicea but also suggest the lack of connectivity between the isolated and fragmented forest stands on Crete.
Analysis of the Profile of Volatile Compounds During the Growing Season in Leaves of Aesculus Trees Differing in Susceptibility to Horse Chestnut Leaf Miner (Cameraria ohridella Deschka & Dimić)
The invasive pest Cameraria ohridella annually colonizes trees of the genus Aesculus across Europe, causing dark brown damage called mines that gradually cover the leaf surface. This study aimed to compare the VOC profiles emitted by chestnut tree leaves with varying susceptibility to the pest and assess whether these profiles change due to larval feeding. The research involved a susceptible tree (Ae. turbinata) and resistant trees (Ae. glabra and Ae. parviflora). Over three growing seasons (2014, 2015, 2016), leaf damage and the profile of VOCs were analyzed biweekly from May to September. Leaf damage increased progressively in Ae. turbinata during all seasons. The VOC profiles differed both qualitatively and quantitatively among the trees and across years. More VOCs were identified in 2014 and 2015 than in 2016. The susceptible Ae. turbinata exhibited the highest VOC diversity in 2014, aligning with severe leaf damage—profiles of VOCs in Ae. turbinata were different from resistant trees. Statistical analysis revealed that in 2014 and 2015, differences in the profile of VOCs between susceptible and resistant trees were apparent near pest-feeding dates. In 2016, VOCs significantly distinguished the profile of susceptible trees that were present before the appearance of the first generation of the pest.
Applying convolutional neural networks for mustard variety recognition
Abstract The aim of this study was to develop and apply a Convolutional Neural Network (CNN) model to recognize and classify white mustard (Sinapis Alba L.) varieties, addressing the complex task of discriminating among 57 varieties. Utilizing a one-dimensional CNN model, the research focused on multivariate analysis based on a set of 15 traits. The CNN architecture included convolutional layers, batch normalization, pooling, flattening, dropout, and dense layers. The model demonstrated effectiveness in classifying varieties, achieving high accuracy and providing valuable insights into potential new varieties. Subset division, a new approach, was applied. Evaluation metrics, including accuracy, F1 score, precision, and recall, were calculated for eight subsets, confirming the model's robust performance. While this study uses mustard as an illustrative example, the method is not limited to this crop and can be extended to other agricultural crops, with potential modifications depending on the specific traits relevant to each crop. The approach contributes to agricultural advancements, offering a reliable tool for breeders to assess variety distinctness and streamline the testing process. The model’s ability to detect unknown varieties further enhances its utility in agricultural research covering a comprehensive and impactful advancement in variety classification.
The Evaluation of Sweetcorn (Zea mays saccharata Sturt.) Infestation of Barnyardgrass (Echinochloa crus-galli) Depending on Weather Conditions and Crop Rotation
This paper focuses on the weed species Echinochloa crus-galli, commonly known as barnyardgrass, which is a persistent threat to crop yield and quality, especially in maize (Zea mays) cultivation. It is one of the most problematic weeds in agricultural fields due to its aggressive growth, adaptability to different environmental conditions and prolific seed production. The incidence of Echinochloa crus-galli in maize fields has increased in recent years. This study aims to provide a comprehensive understanding of the characteristics and behavior of Echinochloa crus-galli, and to suggest effective measures to control it. This research on sweetcorn was conducted from 1992 to 2019 at the Research and Education Center Gorzyń, Złotniki branch, which belongs to the Poznań University of Life Sciences. The evaluation of weed infestation was carried out in experiments focusing on chemical weed control in maize. The experiments were designed as a one-factor randomised block design with four field replications. The condition and the degree of weed infestation (number of weeds and fresh weight of weeds) in the control plots was assessed on an annual basis at the end of June and in July. The aim of the study was to evaluate the dynamic changes in the status and extent of barnyardgrass (Echinochloa crus-galli) infestation in maize grown after various other crops in the Wielkopolska region, with a focus on the weather conditions. The study found that barnyardgrass was most likely to occur when maize was sown after winter wheat in a dry and warm year, and least likely when maize was grown in rotation after winter wheat in a cold year with average rainfall. The proportion of barnyardgrass weed mass in the total weed mass was significantly lower after winter rye than after winter wheat, winter oilseed rape and winter triticale. Further research into the biology and ecology of barnyardgrass is key to effectively controlling this weed and safeguarding sweetcorn yields.
Invertebrates occurring in fruiting bodies of the pathogenic tinder fungus, Fomes fomentarius (Polyporales), in the different types of Polish protected forests
Bracket fungi are usually considered as a cause of economic losses, while they also offer specific microhabitats and have an impact on biodiversity. However, to date this topic has not been sufficiently studied. The aim of this article is to show how the diversity of invertebrate communities, viz. harvest spiders (Aranae, Opiliones), pseudoscorpions (Pseudoscorpionida), two groups of mites (Mesostigmata and Oribatida), springtails (Collembola), and insects (Insecta), inhabiting fruiting bodies of the tinder fungus, Fomes fomentarius, depend on specific characteristics of forests. Samples were collected in three locations: the Białowieża National Park (BNP) characterised by a high degree of forest naturalness, the Bieszczady National Park (BdNP), which was transformed by humans, but has been undergoing naturalisation for several decades, and the Karkonosze National Park affected by a large-scale forest dieback in the 1980s and which for years has been under strong tourist pressure. A total of 20 fruiting bodies of F. fomentarius were collected at each location. In total, 9,821 individuals of invertebrates belonging to 204 species were extracted. The most numerous group was Oribatida (6,595 individuals classified to 106 species), while the most numerous species was Carabodes femoralis (5,216 individuals). The study sites differed in the number of species (the highest one was observed in the BdNP, 115, and the lowest one in the KNP, 88) and number of individuals (the highest one was observed in BdNP, 4,285, and the lowest one in BNP, 1,595), as well as the number of individuals per species (the highest one was observed in the BdNP, 37.26 individuals per 1 species, and the lowest in the BNP, 15.79 individuals per 1 species). A NMDS analysis revealed that the inner distribution of the samples in each of the locations was similar in the case of mountain national parks (BdNP and KNP), while the invertebrate groupings from the BNP and KNP differed the most between one another. The multilevel pattern analysis showed different, specific invertebrate species for each study sites, e.g. Carabodes subarcticus for the BNP, Friesea mirabilis for the BdNP, Oribatella calcarata for the KNP and Dendrolaelaps pini for both mountain national parks. This study shows the uniqueness of invertebrate communities inhabiting fruiting bodies of F. fomentarius and confirms the positive role of this pathogenic fungi in shaping biodiversity. Key words: arthropods; bracket fungi; polypores; anthropopressure; natural forest