ABSTRACT The use of forest seedling banks is recommended for producing seedlings of species essential for specific forest typologies for which propagation poses challenges. However, given the lack of understanding of how human intervention, such as the removal of regenerating individuals from the forest, influences the composition and structure of the plant community, there is a pressing need for further research. Our primary objective here was to identify the effects of seedling removal on natural regeneration in forest communities and to characterize seedling bank dynamics three years after anthropogenic intervention. A randomized block design was used for the experiment, consisting of five removal intensities (0, 25, 50, 75, and 100% removal), with evaluations conducted every three months for three years. All individuals of the shrub-arboreal component between 5-55 cm heights were measured. Collected data were analyzed to determine the impacts of the removal of individuals and the influence of environmental elements on the seedling community. We found that the shrub-arboreal component of the forest community exhibited marked resilience three years following the removal of regenerating individuals. Removal of up to 50% of regenerating individuals does not appear to interfere with plant community dynamics, suggesting species with a high density of individuals in the seedling bank are resilient to the impacts of human intervention. Although climatic seasonality also affects seedling bank dynamics in plant communities, this effect depends on the level of human intervention in an area and, therefore, has been omitted from the analysis.

RESUMO O uso do banco de plântulas da floresta é indicado para produção de mudas de espécies importantes, porém de difícil propagação, para determinada tipologia florestal. No entanto, intervenções como a retirada de indivíduos regenerantes da floresta podem influenciara composição e a estrutura da comunidade de plantas, devendo ter seus impactos previamente estudados. Dessa forma, o presente estudo objetivou identificar os impactos da remoção de plântulas sob a regeneração natural de uma comunidade florestal, bem como caracterizar a dinâmica do banco de plântulas três anos após intervenção antrópica. O experimento foi conduzido no delineamento blocos ao acaso, sendo os tratamentos compostos por cinco intensidades de remoção de indivíduos do banco de plântulas (0, 25, 50, 75 e 100% de remoção) e realizadas avaliações a cada 3 meses, por um período de 3 anos. Foram mensurados todos os indivíduos do componente arbustivo-arbóreo com altura entre 5 e 55 cm. Os dados obtidos foram analisados quanto ao impacto causado pela remoção dos indivíduos e a influência dos elementos ambientais sobre a comunidade de plântulas. Após três anos de observações constatou-se que a vegetação do componente arbóreo-arbustivo apresentou capacidade de resiliência posterior a remoção dos indivíduos regenerantes. De maneira geral, a remoção de até 50% dos indivíduos não interfere na dinâmica da comunidade vegetal, podendo assim ser utilizada para espécies que apresentam elevada densidade de indivíduos no banco de plântulas. A sazonalidade climática direciona a dinâmica do banco de plântulas em comunidades vegetais, no entanto esta influência é dependente do nível de intervenção antrópica a qual a área foi submetida.

ABSTRACT Background: The increase in agricultural production requires sustainable alternatives development for reusing the waste generated, such as bovine manure, to obtain ecological, environmental, and economic benefits. In addition, proper fertilization is one of the main steps in the production of forest species seedlings. Thus, this study aimed to characterize the effect of different substrates formulations based on bovine manure and types of fertilizers on the quality of C. montevidense seedlings and verify if the field confirms the nurseries’ responses. The treatments consisted of three BM-based substrates combinations (S0 - control, no manure; S30 - 30% BM; and S60 - 60% BM) and four types of base fertilizers [Control: no fertilizer, FRF - Fast Release Fertilizer (NPK + fritted trace elements), FRF2 - twice as used in FRF and CRF - Controlled Release Fertilizer]. The substrates quality and the seedlings’ morphophysiological attributes were determined 160 days after sowing, then conducting the best treatments to the field. Results: We verified that the use of bovine manure improved the physical and chemical properties of the substrates. For the C. montevidense cultivation, 30% BM plus CRF provided the best seedling development. The substrate used in the seedlings production influenced the post-planting performance of C. montevidense, and the bovine manure use allows for more significant plant growth in the field. Conclusion: For the cultivation of Citharexylum montevidense, it is recommended to use substrates composed of 30% of bovine manure, associated with 6 g L-1 of controlled-release fertilizer, as it provides higher quality seedlings in shorter production time in the nursery.

ABSTRACT Background: Direct sowing technique is considered a promising tool for reducing costs and increasing species diversity in restoration projects. However, several factors can limit its success, making it necessary for methodological adjustments to be made in order to maximize the emergence, establishment and initial growth of plants. This study aimed to evaluate the influence of the use of fungus Trichoderma asperelloides and hydrogel in the enrichment direct sowing as a strategy to enrich the area in the initial restoration process. The forest species studied were Balfourodendron riedelianum, Cedrela fissilis, Luehea divaricata, Enterolobium contortisiliquum and Parapiptadenia rigida. The experiment was conducted in a factorial design testing absence or presence of the T. asperelloides and absence or presence of hydrogel. Two experiments were established: in the nursery, we evaluations of the emergence of the seedlings were carried out; in the field, we evaluated emergence, survival, height and stem diameter. Results: Under nursery conditions, inoculation and the use of hydrogel did not influence the emergence of species tested. Direct sowing proved to be a promising technique for the enrichment of young restoration plantations in subtropical regions with E. contortisiliquum, P. rigida and C. fissilis. B. riedelianum and L. divaricata seeds did not germinate in the field. Conclusion: The use of T. asperelloides is an efficient strategy to enhance the results of direct sowing, capable of providing higher rates of emergence for E. contortisiliqumm and P. rigida and maximizing the growth in height of E. contortisiliqumm. Under high pluviometric intensity, the use of the hydrogel does not influence the emergence and morphological attributes of the species studied. Background projects However success plants process fissilis T established out field survival diameter Results conditions tested E P C B L Conclusion intensity

RESUMEN: Los viveros forestales que producen seedlings de especies nativas deben poner a disposición una alta diversidad forestal para satisfacer las demandas de los proyectos de recuperación. De esta forma, comprender el comportamiento de las diferentes especies y mejorar la tecnología de producción califica el manejo y reduce las pérdidas. Por lo tanto, se estudió el efecto de la adición de polímero hidroretenedor al sustrato sobre el desempeño de tres especies nativas cultivadas en condiciones de vivero. El diseño experimental fue completamente al azar con un esquema factorial. Se investigaron rasgos de supervivencia, morfológicos y fisiológicos en plántulas. En general, se observó que las especies estudiadas resultaron aptas para la técnica de trasplante con alta supervivencia a pesar de la influencia negativa del hidrogel sobre esta variable en las plántulas. Por otro lado, el uso de polímero hidroretenedor mejoró el crecimiento en altura, diámetro del tallo y la calidad de estas plántulas, demostrando ser una estrategia viable en la producción de seedlings nativas en un vivero.

SUMMARY: Forest nurseries that produce native species seedlings need to make heigh forestry diversity available to supply the demands of forest ecosystem recovery projects. In this way, understanding the behavior of different species and improving production technology improve management and reduce losses. We here studied the effect of the water-retaining polymer addition to the substrate on the performance of three native species grown under nursery conditions. The experimental design was completely randomized with a factorial scheme. Survival, morphological and physiological attributes of seedlings were investigated. In general, it was observed that studied species proved to be suitable for the subculturing technique, with high survival despite of hydrogel negative influence on this variable in seedlings. On the other hand, the use of water-retaining polymer improved growth in height, stem diameter and seedlings quality, demonstrating to be a viable strategy in native seedlings production in a nursery.

RESUMEN: Eugenia uniflora es un árbol frutal de la familia Myrtaceae, nativo de Brasil, Argentina y Uruguay que tiene un alto potencial de uso en proyectos paisajísticos y ambientales, la industria alimentaria y farmacéutica. Sin embargo, todavía falta información sobre la producción de plantas de calidad. El objetivo de este trabajo fue identificar el sustrato adecuado y sus características, en relación al régimen hídrico para la producción de plántulas de E. uniflora. El experimento se realizó en un diseño de bloques al azar, en un esquema factorial, con cuatro tipos de sustratos probados (S1: 100 % turba - sustrato comercial (SC), S2: 80 % SC + 20 % cáscara de arroz carbonizada (CAC), S3: 60 % SC + 40 % CAC, y S4: 40 % SC + 60 % CAC) y cinco regímenes hídricos (RH) (4, 8, 12, 16 y 20 mm dia-1). Se evaluó la altura, el diámetro del cuello, la materia seca y el índice de calidad de Dickson. Los factores influyeron en los atributos medidos de forma aislada. Las plantas cultivadas en S1 presentaron el mayor crecimiento y acumulación de materia seca, siendo los resultados 72 % y 41 % superiores a S3. Eugenia uniflora mostró un crecimiento y una calidad de plántulas superiores en plantas de semillero más pequeñas. El uso de sustrato a base de turba, combinado con el uso de 4 a 8 mm RH dia-1, proporciona un rápido desarrollo de plántulas de E. uniflora en vivero.

SUMMARY: Eugenia uniflora is a fruit tree of the Myrtaceae family, native to Brazil, Argentina and Uruguay that has high potential for use in landscape and environmental projects, food and pharmaceutical industry. However, information on the production of quality seedlings is still scarce. The objective was to identify the appropriate substrate and its characteristics, in relation to the water regime for the production of E. uniflora seedlings. The experiment was conducted in a randomized block design, in a factorial scheme, with four types of substrates being tested (S1: 100 % peat - commercial substrate (CS), S2: 80 % CS + 20 % Carbonized Rice Husk (CRH), S3: 60 % CS + 40 % CRH and S4: 40 % CS + 60 % CRH) and five water regimes (WR) (4, 8, 12, 16 and 20 mm day-1). Height, stem diameter, dry matter and Dickson's quality index were evaluated. Factors influenced the measured attributes in isolation. Seedlings grown in S1 showed the highest growth and accumulation of dry matter. Results are 72 % and 41 % higher than those shown by S3. Eugenia uniflora showed superior growth and quality of seedlings under smaller WR. The use of peat-based substrate, combined with the use of 4 to 8 mm WR day-1, provides rapid development of E. uniflora seedlings in a nursery.

Abstract This study aimed to evaluate different container sizes and substrates formulated with agro-industrial residues to produce Handroanthus heptaphyllus and Schinus terebinthifolius seedlings. The experiment had a completely randomized design with four replications (48 seedlings each), in a factorial scheme (containers × substrates), with two containers (110 and 180 cm3) and ten substrates (agro-industrial residues (crushed peach pits and peel rice) mixed with organic compost). Carbonized and hydrolyzed rice husk (CRH and HRH, respectively) were used. At 90 and 108 days after the emergence of the S. terebinthifolius and H. heptaphyllus seedlings, the morphophysiological attributes were evaluated. Considering the attributes evaluated in this study, the 180 cm3 container promoted more significant seedling growth for both species. Substrates containing up to 20% CRH, HRH, or crushed peach pits (CPP) are indicated for S. terebinthifolius, and those with up to 30% CRH or 10% HRH or CPP are indicated for H. heptaphyllus.

SUMMARY: The study aimed at characterizing the arboreal-shrubby component in fragments of Mixed Ombrophilous Forest, in Rio Grande do Sul State, Brazil. The vegetation survey was performed in four sampled fragments in 57 plots. In the plots, the identification of the individuals and measurement of circumference at breast height (CAP) was carried out, according to the following classes of size: Class I) arboreal strata, individuals with CAP ≥ 30 cm (10 x 20 m); Class II) arboreal strata, individuals with 15 ≤ CAP < 30 cm (10 x 10 m); Class III) established natural regeneration, individuals with 3 ≤ CAP < 15 cm (5 x 5 m) and Class IV) bank of seedlings, individuals with height ≥ 30 cm and CAP < 3 cm (2 x 2 m). The data of Class I constituted a matrix parcel x species, which was used in a multivariate analysis, allowing the classification of groups of plots that characterize microhabitats. The forest fragments presented low floristic richness of typical species of Mixed Ombrophilous Forest. From this environment highlight two main groups, one characteristic of riparian forest and the other from capões. In the riparian forests (GR1), highlighted Eugenia uruguayensis and Gymnanthes klotzschiana. In capões (GR2), the predominant species were Araucaria angustifolia, Podocarpus lambertii and Myrceugenia cucullata. The condition of species in different classes associated with their ecological characteristics allows identifying possible strategies for perpetuation of the arboreal-shrubby component of population and management of the fragments aiming at its conservation.

RESUMEN: El estudio tuvo como objetivo caracterizar el componente arbóreo-arbustivo en fragmentos de Bosque Umbrófilo Mixto. El relevamiento de la vegetación se realizó en cuatro fragmentos muestreados en 57 parcelas. Se identificaron los individuos y se midió la circunferencia a la altura del pecho (CAP), considerando las siguientes clases: Clase I) estrato arbóreo, CAP ≥ 30 cm (10 m x 20 m); Clase II) estrato arbóreo, 15 ≤ CAP < 30 cm (10 m x 10 m); Clase III) regeneración natural establecida, 3 ≤ CAP < 15 cm (5 m x 5 m) y clase IV) banco de plántulas, altura ≥ 30 cm y CAP < 3 cm (2 m x 2 m). Los datos del estrato arbóreo (Clase I) constituyeron una matriz de parcela x especie, la cual fue utilizada en análisis multivariado, permitiendo la clasificación de grupos de parcelas que caracterizan a los microhábitats. Los fragmentos de bosque en cumbres de la sierra presentaron baja riqueza florística de especies típicas del Bosque Umbrófilo Mixto. De este ambiente típico, se destacan dos grupos principales, uno característico de bosques de galería y el otro de bosques en islas (capões). En los bosques de galería (GR1), destacaron Eugenia uruguayensis y Gymnanthes klotzschiana. En los bosques en islas (GR2), las especies predominantes fueron Araucaria angustifolia, Podocarpus lambertii y Myrceugenia cucullata. La condición de especies en las diferentes clases asociadas a sus características ecológicas permite identificar posibles estrategias para perpetuar el componente arbóreo-arbustivo de las poblaciones y de fragmentos buscando su conservación.

Abstract In forest nurseries, one of the factors that change the growth and quality of seedlings is water supply, which has a direct influence on metabolic processes such as stomatal conductance and photochemical efficiency of photosystem II. This study aims to identify the influence of different watering regimes as well as the use of a water-retaining polymer on the initial growth and metabolic processes of Enterolobium contortisiliquum seedlings. The experimental design was in random blocks with a factorial scheme. Morphological attributes, as well as physiological and biochemical attributes were investigated. We verified that the performance of E. contortisiliquum seedlings depends on the watering regime provided to the plants; furthermore, up to 60 days after the application of the treatments, both the height and diameter of the collection and the leaf water potential were similar in the water regimes of 8 mm day-1 and 12 mm day-1.

ABSTRACT Increased production of agro-industrial waste is a global concern, requiring proper disposal. In this sense, they can represent alternative sources for substrate production, adding value to the materials and reducing the cost of seedlings in the nursery. However, their proportions in the mixture should be adequate for better use of water and nutrients, ensuring better seedling quality. The objective of this study was to identify the potential of rice husk and peach kernel residue, as a secondary substrate component, for the production of Eucalyptus grandis seedlings. The carbonated (CRH), hydrolyzed (HRH) rice husk and crushed peach kernel (CPK) were added at 0, 10, 20 and 30% to an organic substrate. The results were submitted to analysis of variance and correlation analysis between the variables of the substrates and the morphological and physiological attributes. The results indicated that the HRH and CPK can add value to the agro-industrial residue when mixed to the organic compound in proportions of 20 and 10%, respectively, being adequate and compatible with the use of CRH in the proportion of up to 30%. Eucalyptus grandis seedlings, after 90 days of cultivation, presented quality to be hardened and dispatched when grown on organic compound substrates with up to 30% CRH, 20% HRH and 10% CPK.

ABSTRACT The use of a forest seedling bank has been recommended as an alternative to increase species richness in forest nurseries, as well as to produce seedlings of species that are diffi cult to propagate, especially those that belong to the late secondary and climax successional groups, which are not as commercially available. However, little is known about the impact of this method on forest dynamics. Thus, the present study aimed to examine the resilience and dynamics of a seedling bank in a remnant of a subtropical seasonal forest belonging to the Atlantic Forest Biome when subjected to different intensities of seedling removal. The experiment was conducted in a random block design in a factorial scheme (5 × 4), with treatments composed of fi ve intensities of removal of individuals from the seedling bank and the four seasons. The treatments were distributed into 18 blocks and the experimental units were composed of 1 m × 2.5 m plots. The resilience of the seedling community was assessed by examining effects of the fi ve removal intensities. The dynamics between the evaluation periods within each treatment were verifi ed by comparing the number of species and seedlings present before the treatments with those in the other evaluation periods. After one year, we found that tree-shrub vegetation had a partial capacity for restoration after withdrawal of individuals from the seedling bank. Our results show that the impact on the regeneration community can absorb the effects of up to 25% seedling removal. The technique of seedling transplantation may be recommended for species that have abundant regeneration, such as Actinostemon concolor, Eugenia rostrifolia, Trichilia claussenii and Nectandra megapotamica.