Hasil untuk "Forestry"

Linjuan Huang, Luocan Zhou, Yandi Qin et al.

Aluminum (Al) toxicity in acidic soils severely restricts plant growth, particularly reducing the productivity of fast-growing timber species—Eucalyptus. Silicon (Si), a beneficial element, can alleviate Al toxicity, but its underlying mechanisms in tree species with contrasting Al tolerance remain unclear. Here, we investigated the effects of Si addition on plant growth, Al uptake, and rhizosphere microbial community and metabolic composition in an Al-sensitive species (Eucalyptus tereticornis) and an Al-tolerant species (Eucalyptus urophylla). Results showed that Al stress significantly inhibited the relative growth rates of roots, stems and leaves, and decreased photosynthetic efficiency. However, Si addition effectively reduced these adverse effects by increasing photosynthetic rate, pigment content, water use efficiency, electron transport rate, and maximum photochemical efficiency of PSII. Aluminum stress also increased soil water-soluble, inorganically bonded and exchangeable Al, promoting root Al accumulation, which was higher in E. urophylla than in E. tereticornis. Microbiome and metabolome analyses revealed species-specific mechanisms by which Si alleviates Al toxicity. In E. tereticornis, Si directly increased bacterial, fungal and metabolite diversity, which facilitated the immobilization of water-soluble and exchangeable forms into less bioavailable forms, including organically bonded, hydrates, and hydrous oxides, thereby reducing Al uptake and upward translocation. In E. urophylla, Si indirectly increased bacterial and metabolite diversity, and recruited specific microbial taxa, including Candidatus Solibacter, Acidothermus, and Occallatibacter, thereby promoting Al uptake, upward translocation and internal detoxification. Our findings reveal distinct Si-mediated mechanisms for alleviating Al toxicity in Eucalyptus, offering practical guidance for the management of Eucalyptus forests in acidic soils.

Fan Liu, Hongli Pu, Songwen Tan et al.

The genus <i>Scincella</i> Mittleman, 1950 of the family Scincidae currently includes 50 species. However, due to challenges in sample collection, the taxonomy and phylogeny of this genus remain poorly resolved. This study conducted a taxonomic study of the genus <i>Scincella</i> based on three mitochondrial gene fragments (12S, 16S, COI) combined with morphological comparisons. The results indicated the specimens collected in Heishui County, Sichuan Province, China, represented a previously undescribed species. This new taxon is formally described as <i>Scincella heishuiensis</i> <b>sp. nov</b>. Phylogenetically, the new species is most closely related to <i>S. wangyuezhaoi</i>, which is another species recently described in Wenchuan County, Aba Prefecture, Sichuan Province. As a new species, the uncorrected genetic distance between this new species and its closest relative within the genus, as calculated based on 16S rRNA, is 5.45%. The new species can be distinguished from other closely related species by the following morphological characters: (1) 4 dorsal scale rows between dorsolateral stripes; (2) 5–7 superciliary; (3) 28 midbody scale-rows; (4) 24–25 gulars; (5) during the breeding season, the ventral scales and preanal exhibit a reddish-brown color; and (6) a black lateral stripe extends from behind the eye to the posterior third of the tail near the cloaca. In the phylogenetic analysis, the new species and <i>S. wangyuezhaoi</i> form an independent lineage, distinctly separate from all other taxa included in the study. The new species has currently been recorded and discovered in Heishui County in Sichuan Province, China. This description thus increases the number of members in the genus <i>Scincella</i> in China to 17 species.

Shiming Lin, Bifang Huang, Li-li Zhao et al.

Gene cloning is an important step in investigating gene structure and function. To verify gene sequence, Sanger sequencing is used, which may produce several overlapping sequencing files that need to be merged before alignment to the target gene sequence is performed. Previously, we reported the Python program to Merge Sanger sequences (https://peerj.com/articles/11354/), which ran in command line and relied heavily on EMBOSS suite. In this updated version of the program, we have made several remarkable improvements. It provides a graphical user interface (GUI) written with tkinter, which is convenient and stable. It does not require users to rename the input sequences before performing merging. With regard to the implementation, the updated version utilizes Python function (Align.PairwiseAligner) to align adjacent sequences, which is more flexible (can adjust program parameter i.e., the number of first-time consecutive matching bases). The new version of the program makes merging Sanger sequences much more convenient and facilitates gene study.

Ivan Arismendi, Stanley V. Gregory, Douglas S. Bateman et al.

Abstract Decreases in body sizes of animals related to recent climate warming can affect population persistence and stability. However, direct observations of average sizes over time and their interrelationships with underlying density-dependent and density-independent processes remain poorly understood owing to the lack of appropriate long-term datasets. We measured body size of two species common to headwater streams in coastal and Cascades ecoregions of the Pacific Northwest of North America over multiple decades, comparing old-growth and managed forests. We found consistent decreases in median length of Coastal Cutthroat Trout Oncorhynchus clarkii clarkii, but a coexisting species, the Coastal Giant Salamander Dicamptodon tenebrosus, appears to be more resilient to size changes over time. Based on observed trends, adult trout have decreased in length by 6–13% over the last 30 years. Length decreased more in larger compared to smaller animals, suggesting that these effects reflect changes in growth trajectories. Results from a model-selection approach that included hydroclimatic and biological information as covariates in one of our study ecoregions demonstrated that stream temperature alone did not explain observed length reductions. Rather, a combination of density-dependent (animal abundances) and local density-independent factors (temperature, habitat, and streamflow) explained observed patterns of size. Continued decreases in size could lead to trophic cascades, biodiversity loss, or in extreme cases, species extirpation. However, the intricate links between density-independent and density-dependent factors in controlling population-level processes in streams need further attention.

Mekuanent Tebkew, Zebene Asfaw, Adefires Worku

Farmers in Ethiopia have been vulnerable to climate change in recent decades. In the face of this change, farmers have managed agroforestry systems to maintain their livelihoods. However, studies exploring the role of agroforestry in reducing household vulnerability are lacking in Northwestern Ethiopia. The objectives of the study were to (i) investigate households’ livelihoods vulnerability to climate change in Northwestern Ethiopia; (iii) assess the role of agroforestry in mitigating the negative impacts of climate change on farmers livelihoods. Key informant interviews, in-depth interviews, household surveys (387), and focus group discussions were used to collect the data. Descriptive statistics, principal component analysis, the X2-test, and the t-test were run to analyze the data. The findings revealed that households are vulnerable to rising temperatures, rainfall variability, frost, disease and pests, erosion, hailstorms, price hikes, wildlife damage to crops, and health stress. Agroforestry non-practitioners had a higher livelihood vulnerability index (LVI) (0.42 ± 0.081) than practitioners (0.46 ± 0.079). The Livelihood Vulnerability-Intergovernmental Panel for Climate Change Index (LVI-IPCC) showed that AF non-practitioners had a higher exposure (0.58), sensitivity (0.54) index, and a lower adaptive capacity index (0.44) than the exposure (0.34), sensitivity (0.38), and adaptive capacity index (0.51) of practitioners. Plant diversity, income level and diversity, livelihood activities, social network, and food security status of farmers were improved by agroforestry. Farmers were therefore less susceptible to adverse climate shocks. Thus, the AF system could be part of future adaptation and resilience programs that provide dependable tools to minimize households’ vulnerability to climate shocks. However, management guidelines, such as understanding local ecosystems, setting clear objectives, choosing suitable species, planning for diversity, considering the market, and regular maintenance and monitoring, are needed for agroforestry to improve its contribution.

Elina Mauramo, Tea Lallukka, Noora Kanerva et al.

Abstract Background and objectives Associations between fruit and vegetable consumption and mental health have been observed, but studies comparing different types of plant foods are sparse. This study among Finnish municipal employees examined associations of the consumption of a range of different plant foods with emotional well-being (EWB). Data and methods We used survey data from the Helsinki Health Study conducted in 2017 among 19–39-year-old employees of the City of Helsinki, Finland (N = 5898, response rate 51.5%, 80% women). Consumption of plant foods, including fruit, berries, fresh and cooked vegetables and wholegrain bread, was measured by a food frequency questionnaire and dichotomised into daily/non-daily consumption. The EWB scale of the RAND-36 questionnaire was dichotomised, with the lowest quartile indicating ‘poor EWB’ and the three higher quartiles indicating ‘good EWB’. We used logistic regression for analysing the associations between plant food consumption and EWB. Analyses were sex-stratified and age, socioeconomic circumstances and psychosocial working conditions were adjusted for. Results Prevalence of daily consumption of plant foods varied from 25% for berries and cooked vegetables to 70% for fresh vegetables. Daily consumption was associated with good EWB among both women and men. The strongest age-adjusted association was found for fresh vegetables, with women (OR 1.48, 95% CI 1.27–1.74) and men (OR 1.86, CI 1.37–2.52) with daily consumption having clearly higher odds of good EWB compared to non-daily consumers. Associations slightly attenuated but mostly remained after adjusting for socioeconomic circumstances and working conditions. Conclusions More frequent plant food consumption was associated with good EWB. Thus, the results support the need for interventions that investigate whether the promotion of plant food consumption could show potential mental health benefits among employees.

Alexandre Miguel do Nascimento, Roberto Carlos Costa Lelis, Delanie Lima da Costa et al.

RESUMO Madeiras de pinus e eucalipto foram coladas variando a quantidade de adesivo, pressão de colagem e diluição do resorcinol. As resistências das juntas coladas e da madeira sólida foram determinadas, juntamente com a percentagem de falhas e massa especifica. Na madeira de pinus, os melhores resultados de resistência foram obtidos para taxa de aplicação de 600 g/m2 e pressão de colagem de 1,0 MPa. Estatisticamente, as diluições em até 10% e 15%, respectivamente, para pinus e eucalipto, tiveram o mesmo desempenho do adesivo não diluído. Na taxa de aplicação de 600 g/m2, a resistência média das juntas coladas de pinus ultrapassou a resistência da madeira sólida, e as de eucalipto também , nas diluições até 15% na pressão de 1,0 MPa. A quantidade de 300 g/m2 pode ser considerada aceitável em ambas madeiras, pois as resistências das juntas coladas atingiram as resistências das madeiras sólidas.

Timo M. Takala, Samira Mokhtari, Susanna L. Ahonen et al.

IntroductionLactococcus is a genus of lactic acid bacteria used in the dairy industry as a starter. Lactococci have been found to produce altogether more than 40 different bacteriocins, ribosomally synthesized antimicrobial proteins. All known Lactococcus spp. bacteriocins belong to classes I and II, which are mainly heat-resistant peptides. No class III bacteriocins, bigger heat-sensitive proteins, including phage tail-like bacteriocins, have been found from the Lactococcus spp. Unlike phage tail-like bacteriocins, prophage lysins have not been regarded as bacteriocins, possibly because phage lysins contribute to autolysis, degrading the host's own cell wall.MethodsWild-type Lactococcus lactis strain LAC460, isolated from spontaneously fermented idli batter, was examined for its antimicrobial activity. We sequenced the genome, searched phage lysins from the culture supernatant, and created knock-out mutants to find out the source of the antimicrobial activity.Results and discussionThe strain LAC460 was shown to kill other Lactococcus strains with protease- and heat-sensitive lytic activity. Three phage lysins were identified in the culture supernatant. The genes encoding the three lysins were localized in different prophage regions in the chromosome. By knock-out mutants, two of the lysins, namely LysL and LysP, were demonstrated to be responsible for the antimicrobial activity. The strain LAC460 was found to be resistant to the lytic action of its own culture supernatant, and as a consequence, the phage lysins could behave like bacteriocins targeting and killing other closely related bacteria. Hence, similar to phage tail-like bacteriocins, phage lysin-like bacteriocins could be regarded as a novel type of class III bacteriocins.

Taimoor Hassan Farooq, Muhammad Adnan Bukhari, Muhammad Shahid Irfan et al.

Abiotic stresses, such as high temperature and drought conditions, greatly influence the development of plants and the quality and quantity of products. Barley (<i>Hordeum vulgare</i> L.) crop production is largely impacted by drought, affecting growth, yield, and ultimately the productivity of the crop in hot arid/semi-arid conditions. The current pot experiment was directed to observe the outcome of nicotinic acid (NA) treatments on barley’s physiological, biochemical, and production attributes at two capacity levels, i.e., 100% normal range and withholding water stress. Randomized complete block design (RCBD) was used during the experimentation with the two-factor factorial arrangement. NA was applied exogenously by two different methods, i.e., foliar and soil application (fertigation). NA solution contained various application levels, such as T1 = control, foliar applications (T2 = 0.7368 gL⁻¹, T3 = 1.477 gL⁻¹, T4 = 2.2159 gL⁻¹), and soil applications (T5 = 0.4924 gL⁻¹, T6 = 0.9848 gL⁻¹, and T7 = 1.4773 gL⁻¹). Results depicted that, overall, foliar treatments showed better effects than control and soil treatments. Plant growth was preeminent under T4 treatment, such as plant height (71.07 cm), relative water content (84.0%), leaf water potential (39.73-MPa), leaf area index (36.53 cm²), biological yield (15.10 kgha⁻¹), grain yield (14.40 kgha⁻¹), harvest index (57.70%), catalase (1.54 mmolg⁻¹FW⁻¹), peroxidase (1.90 g⁻¹FWmin⁻¹), and superoxide dismutase (52.60 µgFW⁻¹) were superior under T4 treatment. Soil plant analysis development (54.13 µgcm⁻²) value was also higher under T4 treatment and lowest under T7 treatment. In conclusion, NA-treated plants were more successful in maintaining growth attributes than non-treated plants; therefore, the NA foliar treatment at the rate of 2.2159 gL⁻¹ is suggested to find economical crop yield under drought conditions. The present study would contribute significantly to improving the drought tolerance potential of barley through exogenous NA supply in water deficit areas.

Yağmur Biricik, Ünal Akkemik, Nesibe Köse

Nisa Leksungnoen, Suwimon Uthairatsamee, Tushar Andriyas

Rosewood and Teak are valuable timber species, which have been heavily logged from both natural forests and plantations. Climate change has also contributed to a reduction in their numbers. We studied their light adaptability at the seedling stage to quantify the growth and physiological characteristics under 10% and 100% of full sunlight. Rosewood performed better, as indicated by the relative growth rate, chlorophyll content, and chlorophyll efficiency, under both shade and sunlight. We also simulated a sudden change in light intensity (gap opening up in the canopy) by exposing seedlings, previously under shade, to full sunlight. Rosewood seedlings responded faster (higher relative growth rate) to changing light conditions relative to Teak. We conclude that Rosewood seedlings can be planted either under shade, or in full sunlight, or in a location experiencing sudden change from shade to sunlight, while Teak seedlings should be planted under at least 10% sunlight, but not in full sunlight, as it can lead to chlorophyll and tissue damage.

Ziqiang Bao, Cheng Li, Cheng Guo et al.

The Himalayan marmot (<i>Marmota himalayana</i>) mainly lives on the Qinghai-Tibet Plateau and it adopts multiple strategies to adapt to high-altitude environments. According to the principle of convergent evolution as expressed in genes and traits, the Himalayan marmot might display similar changes to other local species at the molecular level. In this study, we obtained high-quality sequences of the <i>CYTB</i> gene, CYTB protein, <i>ND3</i> gene, and ND3 protein of representative species (n = 20) from NCBI, and divided them into the marmot group (n = 11), the plateau group (n = 8), and the Himalayan marmot (n = 1). To explore whether plateau species have convergent evolution on the microscale level, we built a phylogenetic tree, calculated genetic distance, and analyzed the conservation and space structure of Himalayan marmot ND3 protein. The marmot group and Himalayan marmots were in the same branch of the phylogenetic tree for the <i>CYTB</i> gene and CYTB protein, and mean genetic distance was 0.106 and 0.055, respectively, which was significantly lower than the plateau group. However, the plateau group and the Himalayan marmot were in the same branch of the phylogenetic tree, and the genetic distance was only 10% of the marmot group for the ND3 protein, except <i>Marmota flaviventris</i>. In addition, some sites of the ND3 amino acid sequence of Himalayan marmots were conserved from the plateau group, but not the marmot group. This could lead to different structures and functional diversifications. These findings indicate that Himalayan marmots have adapted to the plateau environment partly through convergent evolution of the ND3 protein with other plateau animals, however, this protein is not the only strategy to adapt to high altitudes, as there may have other methods to adapt to this environment.

Ruixu Chen, Tian Xu, Dejun Hao et al.

Two sibling weevil species, <i>Pissodes strobi</i> Peck and <i>P. nemorensis</i> Germar (Coleoptera: Curculionidae), can form reduced-fitness hybrids in the laboratory, but neither their premating isolation mechanisms nor mating behaviors are well-understood. Cuticular hydrocarbons (CHCs) have been reported as crucial chemical cues in mating recognition in many insects, including weevils, and, thus, may also mediate the mating behavior of <i>P. strobi</i> and <i>P. nemorensis</i>. We conducted a series of behavioral observations, bioassays, and chemical analyses to investigate the role of CHCs in their mating behavior. Copulation behavior of both species followed similar steps: approaching, mounting, tapping, aedeagus extrusion, and copulation. In <i>P. strobi</i>, hexane extraction significantly reduced the number of successful male copulations compared with freeze-killed females. Conversely, significantly fewer <i>P. nemorensis</i> males copulated with dead females compared with live females. No significant differences were detected among hexane-extracted, freeze-killed or recoated female carcasses to <i>P. nemorensis</i>. These findings suggested that female cuticular extracts contain important cues in mate recognition in <i>P. strobi</i> but not in <i>P. nemorensis</i>. We identified 21 CHCs from both species with variation in abundances between sexes and seasons. Discriminant analysis revealed incomplete overlap of CHC compositions in females of the two species in summer, when hybridization potentially occurs.

Nyoman J Wistara, Wulan Starini, Fauzi Febrianto et al.

Modified lignin with improved reactivity can be a potential alternative for synthetic phenol formaldehyde resin for the adhesive of wood composite. Direct hydroxymethylation of kenaf in the present experiments was intended to increase lignin reactivity, and therefore was expected to result in satisfying properties of binderless MDF. The stem of kenaf was refined in a disk refiner and the refined fibers were hydroxymethylated in various levels of alkalinity. The concentration of NaOH during hydroxymethylation was of 3%, 6% and 12%. Wet process was applied to produce MDF (30 cm x 30 cm x 1 cm) with target density of 0.65 g/cm³. Physical and mechanical properties of MDF were measured in accordance with the standard procedure of JIS A 5905: 2003. Chemical changes in the surface of pulp and the change of board crystallinity were evaluated by FTIR-KBr method and X-Ray Diffractometry (XRD), respectively. Density, moisture content, and screw withdrawal of the board increased with increasing of NaOH concentration. Thickness swelling, water absorption, MOE and MOR increased up to 3% concentration of NaOH. The IB and heat conductivity of MDF were not influenced by NaOH concentration. Increasing OH groups due to hydroxymethylation was thought to be the origin of high water absorption and thickness swelling of the resulting boards. Higher alkalinity during hydroxymethylation stage was likely increasing cellulose crystallinity that brought about increasing board density. However, chemical modification of the fiber was thought to be more influential to the bending strength and stiffness of the resulting fiberboard. Hydroxymethylation of kenaf pulp was successfully improved board properties. Except for the moisture content, thickness swelling and internal bonding (at 0% and 3% NaOH concentration), all properties of the MDF satisfied the requirement of JIS A 5905: 2003 (type 5) standard.

John A. Kershaw, Aaron R. Weiskittel, Michael B. Lavigne et al.

Abstract Background A novel approach to modelling individual tree growth dynamics is proposed. The approach combines multiple imputation and copula sampling to produce a stochastic individual tree growth and yield projection system. Methods The Nova Scotia, Canada permanent sample plot network is used as a case study to develop and test the modelling approach. Predictions from this model are compared to predictions from the Acadian variant of the Forest Vegetation Simulator, a widely used statistical individual tree growth and yield model. Results Diameter and height growth rates were predicted with error rates consistent with those produced using statistical models. Mortality and ingrowth error rates were higher than those observed for diameter and height, but also were within the bounds produced by traditional approaches for predicting these rates. Ingrowth species composition was very poorly predicted. The model was capable of reproducing a wide range of stand dynamic trajectories and in some cases reproduced trajectories that the statistical model was incapable of reproducing. Conclusions The model has potential to be used as a benchmarking tool for evaluating statistical and process models and may provide a mechanism to separate signal from noise and improve our ability to analyze and learn from large regional datasets that often have underlying flaws in sample design.

Nana Haryanti, Paimin Paimin, Sukresno Sukresno

Fungsi daerah aliras sungai (DAS) sebagai suatu ekosistem tidak hanya bertumpu pada kawasan hutan saja, namun juga meliputi kawasan budidaya tanaman dan kawasan pemukiman. Oleh karena itu pengelolaan DAS perlu memberikan perhatian pada manusia dan aktivitasnya sebagai bagian dari sistem DAS. Tujuan penelitian ini adalah untuk mendeskripsikan kondisi sosial masyarakat di sub DAS Merawu dan Bungo, dan pola bagaimana mereka mengelola sumber daya alamnya. Penelitian dilakukan di sub DAS Merawu dan Batang Bungo. Metode observasi dan interview digunakan untuk mengumpulkan data. Tujuan dari observasi dan interview adalah untuk mengeksplorasi kondisi sosial dari petani dan mengembangkan kejadian-kejadian, aktivitas, dan persepsi dari subyek penelitian. Data kemudian dianalisa secara deskriptif. Hasil penelitian menunjukkan bahwa terdapat perbedaan kondisi sosial pada masyarakat sub DAS Merawu dan Batang Bungo, yang dipengaruhi oleh interaksi antara kondisi sosial dan alam. Hutu sub DAS Merawu adalah lahan kering dan dimanfaatkan untuk pertanian tanaman semusim, dan Iahan di hilir sub DAS Merawu adalah persawahan. Laban di sub DAS Bungo dimanfaatkan untuk perkebunan karet, keadaan ini disebabkan lahan tidak memungkinkan dimanfaatkan untuk pertanian tanaman semusim secara intensif. Kegiatan dasar wilayah baik di sub DAS Merawu dan Bungo adalah sektor pertanian. Tingkat pendidikan responden umumnya masih rendah, berakibat pada rendahnya praktek konservasi tanah karena rendahnya pengetahuan dan pemahaman mengenai konservasi terutama di sub DAS Bungo. Sementara itu rendahnya praktek konservasi tanah di sub DAS Merawu lebih disebabkan oleh pertanian lahan kering. Kontribusi pertanian pada pendapatan rumah tangga di sub DAS Merawu adalah 95% berasal dari pertanian lahan kering, sedangkan di sub DAS Bungo kontribusi sektor pertanian mencapai 68% berasal dari perkebunan karet. Jumlah petani besar dengan kepemilikan lahan lebih dari I Ha di Sub DAS Merawu sebesar 33,3%, dan jumlah petani besar dengan kepemilikan lahan lebih dari 3 Ha di sub DAS Bungo adalah 36,2%. Luas kepemilikan lahan di Jawa akan berpengaruh pada status sosial dalam masyarakat, sedangkan di Sumatra status sosial dalam masyarakat lebih dipengaruhi oleh kemampuan dan kecakapan.

Yousefi Sonia, Kartoolinejad Davoud, Bahmani Mohammad et al.

The study was conducted to evaluate the potential of different strains of plant growth-promoting rhizobacteria (PGPR) to reduce the effects of salinity stress on the medicinal hopbush plant. The bacterium factor was applied at five levels (non-inoculated, inoculated by Pseudomonas putida, Azospirillum lipoferum + Pseudomonas putida, Azotobacter chroococcum + Pseudomonas putida, and Azospirillum lipoferum + Azotobacter chroococcum + Pseudomonas putida), and the salinity stress at six levels: 0, 5, 10, 15, 20, and 50 dS m-1. The results revealed that Pseudomonas putida showed maximal germination percentage and rate at 20 dS m-1 (18.33% and 0.35 seed per day, respectively). The strongest effect among the treatments was obtained with the treatment combining the given 3 bacteria at 15 dS m-1 salinity stress. This treatment increased the root fresh and dry weights by 31% and 87.5%, respectively (compared to the control). Our results indicate that these bacteria applied on hopbush affected positively both its germination and root growth. The plant compatibility with the three bacteria was found good, and the treatments combining Pseudomonas putida with the other one or two bacteria discussed in this study can be applied in nurseries in order to restore and extend the area of hopbush forests and akin dry stands.

Xiaonan Yu, Qi Wang, Jianjun Zhang et al.

Starch and soluble sugar concentrations, α-amylase activity and soluble protein of Hippeastrum vittatum ‘Red Lion’ bulbs were assessed under different storage temperatures and storage periods. Bulbs were stored for 45 days at 20°, 12°, 8° or 4°C. Starch concentration decreased most at 4°C on the 45th day, changing from 29.7% to 10.9% in the exterior scales and from 33.0% to 13.0% in the interior scales. The α-amylase activity in the exterior scales, except at 4° and 8°C, decreased significantly between 0 and 15 days of storage, and then increased significantly from the 15th day until the end of the trial. The soluble sugar concentration increased most at 4°C: in the exterior scales it changed from 54.73 to 153.93 mg•g-1 while in the interior scales it increased from 39.67 to 148.11 mg•g-1. The soluble protein concentration in all treatments peaked on the 30th day at 8°C in the exterior scales (2.15 mg•g-1) and at 12°C in the interior scales (2.17 mg•g-1). Understanding these physiological and biochemical changes in the bulbs of H. vittatum after storage would serve as a reference for bulb dormancy mechanisms in future studies.

V. Pohjonen, T. Pukkala

Rodrigo Ferreira da Silva, Fábio Luiz Fleig Saidelles, Alessandro Salles da Silva et al.

Copper contamination has become common in areas of mining and grape culture in Rio Grande do Sul. The aim of this study was to evaluate the influence of the dose of copper on growth and seedling quality of acoita-cavalo and aroeira-vermelha. The experimental design was completely randomized in a factorial scheme (2 x 5), using two forestry species and five copper doses: 0, 64, 128, 192 and 256 mg kg-1 of soil, with five replications. Plant height, collar diameter, dry mass weight of root system and shoot, length and surface specific area of root system and index of seedlings quality were evaluated and relation between shoot height and haste diameter, shoot height and shoot dry mass weight and Dickson quality index were assessed. The results showed that the copper doses tested did not change the quality of aroeira-vermelha seedlings but acoita-cavalo displayed better quality with the application of 64 mg kg-1 Cu. Copper primarily affected the acoita cavalo and aroeira-vermelha root system. Aroeira vermelha was more tolerant to copper toxicity than acoita-cavalo and displayed better quality at higher copper doses.