Southern Brazilian Forest Research Articles

Araucaria angustifolia and Picrasma crenata extracts as potential agents for the control of phytopathogenic fungi of agricultural interest

To expand knowledge about native species in southern Brazil, different types of extracts from the thin vinaceous bark of A. angustifolia and fragments of branches of P. crenata were evaluated. These were crushed and kept for fifteen days in contact with hydroalcoholic solutions at 70 % v/v and ethanolic (96 % v/v), seven days in the cold aqueous extract, and through the decoction process for 10 min. Afterward, they were evaluated at concentrations of 1.0 %, 2.5 %, 5.0 %, 10.0 %, and 20.0 % v/v on the mycelial development of the phytopathogenic fungi Colletotrichum gloeosporioides, Botrytis cinerea, and Sclerotinia sclerotiorum. The levels of phenolic compounds and total flavonoids were evaluated, and the alcoholic extracts of A. angustifolia had the highest total phenolic content. The main phenolic compounds identified in the P. crenata extract were resveratrol, followed by herperidin, rutin, ferulic acid, and kaempferol, and the main chemical compounds identified in the extracts of A. angustifolia were quercetin, rutin, ferulic acid, kaempferol, and gallic acid. A. angustifolia extracts and P. crenata, during the decoction, were more effective in controlling the phytopathogens C. gloeosporioides and B. cinerea from a concentration of 5 % v/v. The fungus S. sclerotiorum was moderately inhibited in hydroalcoholic extracts at 70 % v/v of P. crenata and A. angustifolia at 1.0 % and 2.5 % v/v concentrations. Effectively controlling these phytopathogenic fungi of agricultural importance confers importance on the conservation of these native species of socio-biodiversity in the Atlantic Forest in southern Brazil.

Indirect Effects of Cattle Trampling on the Structure of Fruit-Feeding Butterfly Assemblages Inhabiting Restinga Forests in Southern Brazil

The impacts of anthropogenic activities are increasing at alarming rates, leading to biodiversity loss and the displacement of native habitats. One of the main contributors to human disturbances is livestock farming, which degrades native habitats through cattle grazing and trampling. To understand these impacts, we investigated the effects of cattle trampling on the structure and diversity of fruit-feeding butterflies in Restinga forests of southern Brazil. We addressed questions regarding the effects of cattle raising on butterfly diversity and composition, identified indicator species, and examined the influence of environmental variables on butterfly richness, dominance, abundance, and species composition. Our dataset comprises the long-term monitoring of fruit-feeding butterflies in Restinga forests from 2014 to 2019, across sites with low, medium, and high levels of disturbance due to cattle trampling. We found that medium and high levels of disturbance increased butterfly richness and abundance, whereas low-level disturbance was associated with lower abundance. Additionally, the species composition of butterflies in medium to highly disturbed sites differed from that in preserved Restinga forests, indicating that any perturbation can markedly alter alpha and beta diversity parameters. These changes simplify the native forest structure, open the canopy, disrupt the understory, and favor butterfly species commonly associated with disturbed forests.

New Species, Host Record, and Male Discovery for Three Messatoporus Cushman (Hymenoptera, Ichneumonidae, Cryptinae) from Brazil

Messatoporus bisignatus Aguiar & Supeleto, sp. nov. is described and illustrated. The new species was extensively reared from trap nests colonized by Auplopus subaurarius Dreisbach, 1963 (Hymenoptera, Pompilidae), in an area of secondary Atlantic Forest in southern Brazil. Two other species, M. elektor Santos, 2013 and M. opacus Santos, 2013, were also reared from the same host, but in lesser numbers. The previously unknown males of M. elektor Santos, 2013, M. opacus Santos 2013 and M. unidentatus Santos, 2013 are described and illustrated. New females and significant morphological variation are reported for these species, previously known only from a few specimens. New geographical records are reported for M. unidentatus (Brazil, two localities in ES), M. elektor and M. opacus (Brazil, two localities in RS).

Lestrimelitta chacoana Roig-Alsina, 2010 (Meliponini, Apidae) in a Semideciduous Atlantic Forest, Southern Brazil

The species of the cleptobiotic bee genus Lestrimelitta Friese, 1903 (Hymenoptera: Apidae) are generally known as a menace to Meliponiculture and Apiculture, that is why it is common to observe recommendations to beekeepers to avoid the proximity of their meliponaries with any Lestrimelitta hives. So, besides other anthropic pressures, the growth of beekeeping may represent a particular threat to its species. In this note we address the distribution of three species recorded in the triple border region of Argentina, Paraguay, and Brazil. One of these species, Lestrimelitta chacoana Roig-Alsina, 2010 (Hymenoptera: Apidae), previously described from the Argentinian Dry Chaco, is recorded for the Semideciduous Atlantic Forest in Southern Brazil where it was already expected to be found due to its previous record in a contiguous forest type in Northeastern Argentina. A discussion about the characters to differentiate it from two other species is made.

Evaluating the impact of historical climate and early human groups in the Araucaria Forest of eastern South America

It has been hypothesized that the Araucaria Forest in southern Brazil underwent expansions in the past, driven either by human groups or by climate fluctuations of the Holocene and Pleistocene. Fossil pollen records of the Paraná pine Araucaria angustifolia, a dominant tree in that forest, provide some insights into when those may have occurred. Still, the timing of those expansions has never been estimated. To infer past range shifts and shed light on their main drivers, we employed next‐generation DNA sequencing (ddRADseq), machine learning, and a comprehensive database of fossil pollen records into a study of historical demographic inference and paleo‐distribution modeling of the Paraná pine. We found that A. angustifolia comprises two populations expanding at different times: one in the Mantiqueira mountain chain, the other in the southern Brazilian plateau. The southern population began to expand during the Last Glacial Period ~ 70 kya, long before human arrival in South America. Still, genetic analyses support that humans later impacted this population, resulting in lower genetic diversity, higher inbreeding, and high levels of gene flow over large distances with a weak pattern of isolation‐by‐distance. It is possible this resulted from human influence on seed dispersal and germination on the southern Brazilian plateau. The Mantiqueira population, in contrast, expanded only recently (~ 3 kya). This timing coincides with Holocene climatic changes and human settlements established further south, although, to date, there is little archeological evidence of human impact in the Mantiqueira. In addition, multitemporal species distribution models built from a combination of present‐day and pollen records infer a range expansion of the Araucaria Forest during glacial times until the cold humid HS1 event (~ 16 kya), when the forest was most widespread, with no evidence of glacial refugia. The combination of genomic and spatial analyses suggests that both human and climatic controls played a role in the dynamics of the Araucaria Forest.

Integrated indicators for the analysis of vulnerability in a socio-ecological system of the Atlantic Forest in southern Brazil

The Brazilian Atlantic Forest, a biodiversity conservation hotspot, is extremely fragmented and threatened by the global urban-industrial economic approach. A small part of what remains is protected by Conservation Units (UC) of varying categories. This makes natural populations in UC's increasingly vulnerable, since these areas are ecologically fragile. This is further compromised by socio-economic marginalization of much of the local human population. Consequently, we analyzed the areas surrounding two protected natural areas in the port city of Paranaguá, in southern Brazil. We analyzed socio-environmental vulnerability in the face of extreme weather events, the risk of flooding and the change in land use of this socio-ecological system, using integrated socioeconomic, demographic, environmental and climate indicators. Results showed that this peripheral population is more vulnerable, compared to other areas of the municipality that have better infrastructure and economic conditions, and improved access to public services and confirming a world-wide trend between population density and the formation of marginalized populations around natural areas, especially in biodiversity hotspots. At the same time, the Conservation Units and the provision of ecosystem services are at risk due to the change in land use and urban expansion in this region, highlighting the need for integrated public policies for this socio-ecological system.

Which plant traits matter? Bromelia antiacantha Bertol. (Bromeliaceae) as a hibernation site for Brachystethus geniculatus (Fabricius) (Hemiptera, Pentatomidae, Edessinae)

ABSTRACT Diapause is a process of decreased metabolic activity in insects. In latitudes with a well-defined cold season, diapause or hibernation is a strategy to survive in periods of resource scarcity. In Pentatomidae, this phenomenon is studied mainly in non-natural environments and with species of economic importance. This work aimed to determine which variables influence the abundance of Brachystethus geniculatus on its hibernation site, Bromelia antiacantha. Samplings were carried out monthly, from July to September of 2019, in a remnant of Atlantic Forest in southern Brazil. The height, diameter, cup height, leaf width, and abundance of bromeliads per plant cluster were evaluated for their correlation with the abundance of B. geniculatus in bromeliads. We collected 24 individuals for analysis of fat bodies, in order to check diapause. We found 70 individuals of B. geniculatus distributed in 33 of the 61 bromeliads examined. The number of B. geniculatus per bromeliad was positively correlated with the cup height, that influences the opening of the leaves and consequently decreases the exposure to environmental weathering, and the number of bromeliads per group, possibly because more leaves and spines around the cup may help avoid predation. Parasitism on B. geniculatus by tachinid flies was recorded in the field.

First Capture of a Jaguar Using a Minimally Invasive Capture System for GPS Tracking in an Isolated Patch of Atlantic Forest in Southern Brazil.

This study presents the first successful capture using GPS tagging of a jaguar (Panthera onca) using a minimally invasive capture system (MICS). We used snare-foot traps and a MICS during two capture campaigns in a fragment of Atlantic Forest in southeastern Brazil. The specimen disarmed snares on different occasions, and capture was only possible with the MICS. The captured jaguar, an estimated 16-year-old adult male, was monitored using a GPS Vertex Plus Iridium collar with an optimal performance of 86% in expected locations. The jaguar's home range (659 km2 by MPC and 174 km2 by 95%K) was within the observed range for the species and the animal was primarily maintained in protected areas. The habitat types most frequently used were native grassland (27.2% of 4798 fixes), marsh (24.8%), and dense lowland forest (24.7%). The use of a MICS for trapping jaguars is a promising technique that shows advantages in terms of efficiency, selectivity, portability, reduced potential risk of injury to animals or trappers, and animal stress compared to other capture methods used for the species.

Frog call transmission in forestry monocultures: Are there drawbacks?

AbstractAnuran males emit advertisement calls for the purpose of attracting females and repelling conspecific males. Call transmission is influenced by the acoustics of the propagation environment, including vegetation. Thus, forestry monocultures of non‐native trees represent artificial environments that could modify call transmission. These monocultures have substituted large areas of Atlantic Forest in southern Brazil, representing a conservation challenge. Considering this context, we hypothesized that anurans have calls that are less attenuated in their native environment than in forest plantations. To test it, we performed sound transmission experiments using calls of three anuran species native to southern Brazil: Boana bischoffi, B. leptolineata, and Hylodes meridionalis. We compared sound attenuation between the native forest and forestry monocultures (Eucalyptus sp. and Pinus sp. forests), and included distance from the sound source, air temperature, humidity, and vegetation density as cofactors in linear mixed models. Our results show that the advertisement calls of the two tree frogs (Boana) attenuate less in tree plantations than in native forests, while the third species shows either no differences or less attenuation in native forests. Our results can be understood according to differences in natural history and microhabitat use among the studied species. The two tree frog species vocalize perched from vegetation so their calls become better transmitted in forestry monocultures, which have fewer trees than the native forest. On the other hand, H. meridionalis calls from rocks on streams and the propagation is finely tuned to this peculiar microhabitat. We discuss the conservation implications of our findings for anurans and for the Atlantic Forest. Abstract in Portuguese and Spanish are available with online material.

A matter of scale: Local biotic differentiation and potential regional homogenization of understory plant communities in a highly fragmented tropical landscape

Plant communities in highly fragmented tropical landscapes can undergo biotic homogenization and differentiation after land-use changes, such as forest fragmentation. Here we evaluated the beta diversity of understory plant communities in fragmented forest remnants and assessed species geographic distribution to infer potential local and regional scale dependency of homogenization and differentiation pathways in the Atlantic Forest in southern Brazil. More specifically we assessed: (i) community composition; (ii) the frequency of locally rare species, generalists, interior and edge specialists; (iii) the relative contribution of beta diversity components; and (iv) the influence of widely, intermediate and narrowly distributed species to the observed patterns. Understory communities were sampled in a nested design with plots allocated to the interior and edge of forest fragments, and geographic distributions were estimated based on occurrence records from herbaria collections. Our results revealed differences in species composition among fragments and habitat types (edge and interior). Most of the sampled species were classified as locally rare. The turnover component of beta diversity explained a higher proportion of variation in species composition among fragments and habitats. Species richness and abundance were higher in the interior of fragments and most of the recorded species in the study had a wide geographic distribution. Our results support a local community differentiation (high beta diversity) among fragments and habitat types and suggest a potential regional homogenization, given the predominance of widely distributed generalist species in a domain historically characterized by high levels of endemism. We recommend urgent protection and restoration actions on the few remaining fragments of the Atlantic Forest given that each remnant can support different plant assemblages that have been increasingly threatened. Future studies should explicitly consider multiple spatial and temporal scales across fragmented tropical landscapes to better understand links with biotic homogenization and differentiation of ecological communities.

Demography and spatial distribution of a threatened species from the Atlantic Forest in southern Brazil: differences between urban and rural remnants.

Logging and agricultural exploitation have led to the degradation of Araucaria Forest remnants and the alteration of its last preserved patches. This forest typology contains many endangered plant species, as is the case of the tree Oreopanax fulvus Marchal. To support conservation of this species and understand how different landscape matrices can influence its populations, we evaluated the demographic structure and spatial distribution of O. fulvus in two Araucaria Forest remnants in Paraná state. We delimited two plots (urban and rural population), each with 1 ha, subdivided them into 100 subplots (10 x 10 m), and recorded diameter at ground level (DGL), height, and coordinates of two post-germinative developmental stage of individuals. In each subplot, we measured slope, luminosity, and canopy height. We used Ripley's K function analysis to describe distribution patterns of the species and the spatial relationship between mature and juvenile trees. We performed correlations between abundance and environmental and structural variables of the O. fulvus populations. Abundance varied between remnants, from 183 individuals/ha (12 mature and 171 juvenile) to 1306 individuals/ha (10 and 1296). The remnants varied in abundance and plant frequency. The species showed an investment in seedling banks. Most juvenile had DGL up to 3.0 cm and height up to 1.0 m and presented aggregated spatial distribution, while adults had random distribution. In the rural population juvenile abundance were correlated with canopy height (positively) and distance to mature trees (negatively). The slope was correlated for both sites, but oppositely, indicating that other factors might have interfered in the regeneration abundance. The urban remnant showed a high abundance of this endangered species, calling attention for potential studies in urban arborization, management and conservation of these remnants.

Two new land planarian species (Platyhelminthes: Tricladida) from the Cerrado biome in southwestern Brazil

Most Neotropical land flatworm species are known from areas of the Atlantic Forest. Herein, we describe two new land planarian species from areas of semideciduous forest in the Cerrado biome in southwestern Brazil. Paraba aurantia Marques & Leal-Zanchet, sp. nov. can be distinguished from its congeners by the wide black median band on the dorsum, eyes occupying almost the entire dorsal surface, prostatic vesicle twisted and asymmetrical with proximal portions forked, and female atrium with an ample lumen lined by a low epithelium with stratified appearance. Pasipha liviae Marques & Leal-Zanchet, sp. nov. shows a narrow longitudinal dorsal stripe, collar-shaped pharynx, and prostatic vesicle with a pear-shaped proximal portion and a globose distal portion separated by a constriction. In addition, P. liviae can be distinguished from its congeners by molecular analyses from the cytochrome c oxidase subunit I gene (COI). Phylogenetic analyses suggest that P. liviae is closely related to P. hauseri, which occurs in areas of semidseciduous forest in southern Brazil.

First Report of Culturable Skin Bacteria in Melanophryniscus admirabilis (Admirable Redbelly Toad).

Melanophryniscus admirabilis is a small toad, critically endangered with a microendemic distribution in the Atlantic Forest in southern Brazil. The amphibian skin microbiome is considered one of the first lines of defense against pathogenic infections, such as Batrachochytrium dendrobatidis (Bd). The knowledge of skin amphibian microbiomes is important to numerous fields, including species conservation, detection, and quantification of environmental changes and stressors. In the present study, we investigated, for the first time, cultivable bacteria in the skin of wild M. admirabilis, and detected Bd fungus by nested polymerase chain reaction (PCR) technique. Skin swab samples were collected from 15 wild M. admirabilis, and the isolation of bacteria was performed by means of different culture strategies. A total of 62 bacterial isolates being Bacillus (n = 22; 34.48%), Citrobacter (n = 10; 16.13%), and Serratia (n = 12; 19.35%) were more frequently isolated genera. Interestingly, all skin samples tested were Bd negative. Some bacterial genera identified in our study might be acting in a synergic relationship and protecting them against the Bd fungus. In addition, these bacteria may play an essential role in maintaining this species in an environment modulated by anthropic actions. This first report of skin cultivable bacteria from M. admirabilis natural population improves our knowledge of skin amphibian microbiomes, contributing to a better understanding of their ecology and how this species has survived in an environment modulated by anthropic action.

Individual Tree Basal Area Increment Models for Brazilian Pine (Araucaria angustifolia) Using Artificial Neural Networks

This research aimed to develop statistical models to predict basal area increment (BAI) for Araucaria angustifolia using Artificial Neural Networks (ANNs). Tree species were measured for their biometric variables and identified at the species level. The data were subdivided into three groups: (1) intraspecific competition with A. angustifolia; (2) the first group of species that causes interspecific competition with A. angustifolia; and (3) the second group of species that causes interspecific competition with A. angustifolia. We calculated both the dependent and independent distance and the described competition indices, considering the impact of group stratification. Multi-layer Perceptron (MLP) ANN was structured for modeling. The main results were that: (i) the input variables size and competition were the most significant, allowing us to explain up to 77% of the A. angustifolia BAI variations; (ii) the spatialization of the competing trees contributed significantly to the representation of the competitive status; (iii) the separate variables for each competition group improved the performance of the models; and (iv) besides the intraspecific competition, the interspecific competition also proved to be important to consider. The ANN developed showed precision and generalization, suggesting it could describe the increment of a species common in native forests in Southern Brazil and with potential for upcoming forest management initiatives.

Old‐growth structural attributes associated with the last giant subtropical conifers in South America

AbstractGiant Araucaria trees in Brazilian Atlantic forests today are rare but remain critically important for structuring these ecosystems, providing unique and rare habitat elements that can serve as points of reference for their management. Old‐growth Araucaria trees, with their complex crowns and big trunk cavities, supply more important ecological services than smaller trees with simple crowns. Forest ecology managers lack information on the old‐growth structures of Brazilian Araucaria forest, their ecological importance and their potential societal values and uses. In this study, we investigated old‐growth attributes of Araucaria angustifolia and relate their wide structural variability to ecological management goals. In this study, we used currently available data on the last large old Araucaria trees, as well as our own new records, from large trees of 1.6–3.2 m diameter in the Araucaria forests in southern Brazil. In order to quantify the structural attributes of these remnant trees, their main trunks, any reiterated canopy trunks and trunk cavities were measured for diameters, heights and volumes. These old‐growth trees had an average height of 38.4 m, and total tree volumes ranged from 21.5 to 106.6 m3. The biggest reiterated trunk was 1.1 m in diameter and 17 m long, which is larger than most adult Araucaria trees. Number of cavities and number of reiterated trunks were all significantly related to the diameters of these large remnant Araucaria trees; both features are absent in Araucaria <50 cm in diameter. The maximum diameter and average length of reiterated trunks were correlated with the number and size of trunk cavities. Commercial wood values and uses are limited for all trees with main trunk diameters exceeding 1.5 m due to large internal cavities—however, these rare, relictual old‐growth structures are of high ecological value for the local fauna and flora.

Comparative Analysis of the Ecological Functions of Dung Removal and Seed Dispersal among Two Telecoprid and Two Paracoprid Dung Beetles (Coleoptera: Scarabaeidae: Scarabaeinae)

We evaluated the functional capacities of dung removal and secondary seed dispersal by two telecoprid dung beetles, Canthon rutilans cyanescens (Harold) and Deltochilum multicolor Balthasar, and two paracoprid dung beetles, Dichotomius sericeus (Harold) and Phanaeus splendidulus (Fabricius), in a remnant of Atlantic Forest in southern Brazil. We aimed to describe and understand the variability of these behaviors among these species and compare their dung removal capacities by standardized biomass. Two experiments were conducted to evaluate the effect of exposure time to the resource on the functional capacity of the four species and the effect of density on C. r. cyanescens and D. sericeus in arenas with single male/female pairs or groups of three pairs. Beetles were exposed to 30 g of canine feces with artificial seeds, which remained in the field for two, seven, or 21 days in four replicates. The paracoprids were more efficient than the telecoprids in all ecological functions. Canthon r. cyanescens removed significantly more dung with increasing exposure time and density, while D. multicolor showed no significant differences in any ecosystem function. For D. sericeus, time was relevant for increasing dung removal and dispersion of large seeds, while density only affected dung removal. Phanaeus splendidulus removed more dung with increasing exposure time, but its effect on seed dispersal was not significant. When evaluating dung removal capacity by standardized biomass, C. rutilans and D. sericeus were the most efficient species, demonstrating that paracoprids are usually more efficient because of their greater body biomass. As much as the functional capacity of certain ecological functions differs among species, different functional groups provide complementarity in communities. Thus, data on the biology and behavior of species are important in ecosystem functions.

Composition and dynamics of mixed flocks of birds in a remnant of Submontane Atlantic Rain Forest in southern Brazil

Mixed flocks are associations of two or more species that are formed and maintained through mutual behavioral responses, with advantages such as maximizing foraging and protecting against predation. This study aimed to evaluate the composition, temporal dynamics, and presence of core species in mixed flocks of birds in a remnant of the Submontane Atlantic Rain Forest in the Parque Nacional Aparados da Serra, southern Santa Catarina state, Brazil. Data collection took place from October 2016 to September 2017 through monthly campaigns, consisting of three consecutive observation days, with sampling sessions of six hours per day, resulting in a total effort of 216 h of observations. For each contact with the flocks, we recorded the species and number of individuals, stratum of occurrence, substrates of search, and agonistic interactions. We recorded 152 mixed flocks, with a total of 76 species belonging to 24 families, and five orders, with Thraupidae, Tyrannidae, Furnariidae, and Rhynchocyclidae being the richest. The flocks had an average of 4.5 ± 2.7 species and 8.7 ± 5.8 individuals, with richness and the number of individuals being positively correlated (R² = 0.8). Mixed flocks occurred throughout the year. There was a great variation in the number of contacts from October to February (from 5 to 20 contacts). Meanwhile from March to September, the coldest period of the year in the region, the number of contacts did not vary (from 9 to 14 contacts). However, there was no difference in the number of contacts between these months (z = 0.37; p = 0.691). Basileuterus culicivorus and Habia rubica were the core species because, in addition to their high participation (46.7 and 32.9%, respectively), they showed frequent and conspicuous movement and vocalization. Thus, a high capacity to enlist a greater number of individuals from different species for the flocks was demonstrated.

Leaf litterfall, decomposition and nutrients release in a Seasonal Semideciduous Forest in Southern Brazil

Biogeochemical cycling study of ecosystems and their functioning are fundamental for planning conservation practices and management of forest remnants in Brazil. The objective of the study was to characterize the leaf litterfall production rate and the nutrients release via decomposition in a fragment of Seasonal Semideciduous Forest, in Southern Brazil, in advanced stage of regeneration. For two years, evaluations of litterfall and leaf litter decomposition (using the mass loss method with litterbags) were performed monthly, as well as their nutrient content analysis. Annual input of leaf litterfall was 4,532.7 kg ha-1 of dry matter, which promoted, for the two-year period, a supply of 195.5, 9.2 and 55.3 kg ha-1 of N, P and K, respectively. The litter nutrients use efficiency followed the decreasing order P > K > N. The annual decomposition constant for leaf litter was 1.16, reaching a half-life at 215 days, making 84.4% N, 72.7% P and 92.9% K available at the decomposition end of two years. In the two years of collection, the largest deposition rate of litter occurred in the spring, with the highest peak in October, indicating a seasonal deposition behavior. The forest fragment presents high production of leaf litter (66% leaves) and input of N. The rapid decomposition of leaf litter contributes to the release of nutrients over time, N and K initially, and P in the long run. P is limited due to the high efficiency of its use.

INTERANNUAL VARIATION IN THE PHENOLOGICAL BEHAVIOR OF TWO NATIVE TREE SPECIES IN ALLUVIAL FOREST

The vegetative (senescent leaf, mature leaf and budding) and reproductive (bud, anthesis, unripe fruit and ripe fruit) phenological behavior of Gymnanthes klotzschiana (Euphorbiaceae) and Blepharocalyx salicifolius (Myrtaceae) were evaluated for 5 years in a fragment of Alluvial Mixed Ombrophilous Forest in southern Brazil, by the intensity index, seeking to answer the following questions: (i) Do phenological events follow an annual pattern or is there variation over the period? (ii) Which meteorological variables, among temperatures (minimum, mean and maximum) and precipitation, influence the phenophases? Phenological data were correlated with precipitation and minimum, mean and maximum temperatures of the study period. Variations in the intensity of the phenophases were detected between the years analyzed. Correlations with temperatures were identified for some phenophases during the study period. The species showed similar phenological behavior in vegetative phenophases, but variations in the intensity of the phenophases were detected between the years analyzed, which may be responses to annual temperature and precipitation variations. With the obtained data of correlation between the phenophases and the meteorological variables, it was possible to conclude that different meteorological signals are felt by the plants to express their phenophases. It seems that there is a tendency for temperatures to be an important factor that regulates plant phenology, but that the monitoring period may also influence these factors

Recruitment exceeds mortality in subtropical secondary forest after conventional selective logging

Studies on the dynamics of managed forests are essential for planning and executing management strategies. Timber harvesting can modify recruitment rates, mortality, gain and loss of basal area of the remaining stand. In secondary forests, especially in the Atlantic Forest, these studies are still scarce. Our study hypothesis is that the management intervention stimulates the growth of the remaining trees, overcoming the reduction of the growth of the damaged trees and the harvest mortality. We investigated the dynamics of the remaining trees and recruits (in number of individuals and basal area), with DBH ≥ 5 cm, by ecological group of the species, and the damage to the remaining adult individuals. We measured eleven permanent plots with 1.600m² each, before and four years after being harvested in a secondary forest in southern Brazil. We found that the different harvesting intensities significantly influence the forest dynamics, special the annual recruitment rates, while basal area gain/loss showed a weaker relationship to logging intensity. However, the mortality rates are similar in control plots and managed plots. We also observed that in the managed plots, the recruitment rate (5.3 ± 1.9% year-¹) exceeded mortality (2.3 ± 1.2% year-¹). Among ecological groups, we found less recruitment of climax species than of secondary species. In general, the proportion of damage of remaining trees decreased over time. We conclude that the management has modified the forest dynamics, indicating that planning, including adequate cutting limits and low impact harvesting methods are essential for achieving the sustainability of forest management.