Herbivory and leaf expansion of Cyathea phalerata Mart. (Cyatheaceae) in subtropical Atlantic Forest, southern Brazil

Herbivory is an interaction with great impact on plant communities since relationships between herbivores and plants are fundamental to the distribution and abundance of species over time and space. The aim of this study was to monitor the rate of leaf expansion in the tree fern Cyathea phalerata and evaluate the damage caused by herbivores to leaves of different ages and whether such damage is related to temperature and precipitation. The study was performed in a subtropical Atlantic Forest fragment located in the municipality of Caraá, in the northeast hillside of Rio Grande do Sul state, in southern Brazil. We monitored 24 mature individuals of C. phalerata with croziers in a population of approximately 50 plants. Leaf expansion rate, percentage of damaged leaves and leaf blade consumption rate by herbivory were calculated. Monthly means for temperature and accumulated rainfall were calculated from daily data. Croziers of C. phalerata were found to expand rapidly during the first and second months after emergence (3.98 cm day-1; 2.91 cm day-1, respectively). Damage caused by herbivory was observed in all of the monitored leaves, but none of the plants experienced complete defoliation. The highest percentage (57%) of damaged leaves was recorded at 60 days of monitoring, and also the highest monthly consumption rate of the blade (6.04%) occurred with young, newly-expanded leaves, while this rate remained between 1.50 and 2.21% for mature leaves. Rates of monthly leaf consumption and damaged leaves showed positive and strong relationship with each other and with temperature. The rapid leaf expansion observed for C. phalerata can be considered a phenological strategy to reduce damage to young leaves by shortening the developmental period and accelerating the increase of defenses in mature leaves.

Long-Term Suppression of Hardwood Regeneration by Chinese Privet (Ligustrum sinense)

Native hardwood regeneration in the southeast United States is hindered by repeat disturbance events and the presence of invasive species. Our study aimed to determine the ability of native species in an unmanaged urban forest fragment to persist following high winds from hurricane Gustav in 2008 and subsequent salvage logging. In 2009, researchers estimated the density and composition of the regeneration and overstory trees as well as percent crown cover of invasive Chinese privet. Percent Chinese privet cover was visibly high, leading them to believe it may be inhibiting native hardwood establishment. Ten years later in 2019, we returned to the plots to take repeat measurements. Forest composition remains the same and privet crown cover remains high. There has been no increase in regenerating individuals, and overstory trees per hectare and basal area remains low. These results confirm that the heavy Chinese privet presence is persistent long term and will require management to promote reproduction of native overstory tree species.

A new species and a new combination for the subfamily Cunaxinae (Acari: Cunaxidae)

A new species of Cunaxidae, namely Cunaxa bagualensis Wurlitzer & Ferla sp. nov., is described and illustrated based on females and males collected in soil and leaf litter in the Atlantic rainforest biome in a rural forest fragment in Mormaço county, Rio Grande do Sul state, Brazil. Additionally, Armascirus livingstoni Laniecka & Kazmierski, 2021 is transferred to Dactyloscirus based on some observations.

Seasonal and microclimatic effects on leaf beetles (Coleoptera, Chrysomelidae) in a tropical forest fragment in northeastern Mexico

Leaf beetles (Coleoptera: Chrysomelidae) constitute a family of abundant, diverse, and ecologically important herbivorous insects, due to their high specificity with host plants, a close association with vegetation and a great sensitivity to microclimatic variation (factors that are modified gradually during the rainy and dry seasons). Therefore, the effects of seasonality (rainy and dry seasons) and microclimate on the community attributes of chrysomelids were evaluated in a semideciduous tropical forest fragment of northeastern Mexico. Monthly sampling was conducted, between March 2016 and February 2017, with an entomological sweep net in 18 plots of 20 × 20 m, randomly distributed from 320 to 480 m a.s.l. Seven microclimatic variables were simultaneously recorded during each of the samplings, using a portable weather station. In total, 216 samples were collected at the end of the study, of which 2,103 specimens, six subfamilies, 46 genera, and 71 species were obtained. The subfamily Galerucinae had the highest number of specimens and species in the study area, followed by Cassidinae. Seasonality caused significant changes in the abundance and number of leaf beetle species: highest richness was recorded in the rainy season, with 60 species, while the highest diversity (lowest dominance and highest H’ index) was obtained in the dry season. Seasonal inventory completeness of leaf beetles approached (rainy season) or was higher (dry season) than 70%, while the faunistic similarity between seasons was 0.63%. The outlying mean index was significant in both seasons; of the seven microclimatic variables analyzed, only temperature, heat index, evapotranspiration and wind speed were significantly related to changes in abundance of Chrysomelidae. Association between microclimate and leaf beetles was higher in the dry season, with a difference in the value of importance of the abiotic variables. The results indicated that each species exhibited a different response pattern to the microclimate, depending on the season, which suggests that the species may exhibit modifications in their niche requirements according to abiotic conditions. However, the investigations must be replicated in other regions, in order to obtain a better characterization of the seasonal and microclimatic influence on the family Chrysomelidae.

Litterfall and Accumulated Nutrients in Pinus taeda Plantation and Native Forest in Southern Brazil

The dynamics of the production, chemical composition, and accumulated nutrients in litterfall are essential to understand the availability of nutrients and, consequently, possible gains in productivity in different forest types. Thus, the objective of the present study was to evaluate the litterfall and the accumulated nutrients in litterfall in a Pinus taeda plantation and native forest from southern Brazil. Two forest types: (i) an eight-year-old Pinus taeda L. plantation; and (ii) a native forest fragment, located in southern Brazil, were studied for four years. The monthly and annual litterfall production, chemical composition, accumulated nutrients, and nutrient use efficiency of the litterfall were evaluated. The Pinus taeda plantation showed higher values of leaves/needles litterfall and N, P, K, Ca and Mg use efficiency. This demonstrates that Pinus taeda plantations have a high production of needle biomass, which, in turn, has increased cell division, favoring the entry of these nutrients into the soil via decomposition. Our results show that total litterfall production did not significantly influence the accumulated nutrient and nutrient efficiency of litterfall, demonstrating that evaluating litterfall fractionation, such as leaves/needles, twigs and miscellaneous, is essential to understand the quantity and quality of litterfall and, thus, the nutrient cycling, which can contribute to possible silvicultural practices to be implemented, which can provide growth gains in forest types.

Floristic Composition and Community Structure of Epiphytic Angiosperms in an Urban Forest Fragment in the Eastern Amazon

Vascular epiphytes are one of the most important forest components, contributing to microclimatic maintenance. These plants find ideal conditions for development in the Amazon due to the spatial heterogeneity and high temperature and humidity typical of this biome. In recent years, the Brazilian Amazon has undergone dramatic changes in its landscape, mainly due to the increase in deforestation and fire rates. We present here the floristic composition and analyze the community structure of epiphytic angiosperms of an urban forest fragment in Eastern Amazon. A total of 71 epiphytic individuals were recorded belonging to eight species and four families. Orchidaceae was the most representative family, corroborating the pattern for surveys of epiphytic diversity in the Neotropical region. Epiphytic species were found on 24 individuals of 10 tree species. The epiphytic importance value (IVe) was low for all species, except for Aechmea tocantina and Rhipsalis baccifera. Cactaceae was the family with the highest IVe. Most epiphytes were found in the crown of trees (83.1%). The diversity index of the fragment was H’ = 1.80 and the equity index was J= 0.87, reflecting the absence of highly dominant species. Conservation of urban forest fragments is necessary for the maintenance of epiphytic flora and ecosystem services.

Spawning behavior of Aedini (Diptera: Culicidae) in a remnant of Atlantic Forest in the state of Rio de Janeiro

Background Mosquito assemblages are organized along an ecological gradient, including small habitats where interspecific competition predominates and large permanent habitats where predation predominates. This study aimed to analyze the oviposition behavior of mosquitoes regarding the preference for traps installed at two different heights with regard to ground level and the tendency to share spawning sites in an Atlantic Forest fragment in Nova Iguaçu, State of Rio de Janeiro, Brazil. Methods The eggs were collected from April 2018 to March 2019. Twelve ovitraps were used, randomly distributed in trees at ground level and at a height of 3 m in a forest environment. Results They were sequentially numbered, monitored, and replaced every 2 weeks. Among the 5818 eggs collected, 3941 hatched, 3756 reached the pupa stage, and 2370 reached the adult stage. The most abundant species were Aedes albopictus (63%) and Haemagogus leucocelaenus (35%), followed by Aedes terrens (2%) and Haemagogus janthinomys (1%). Analyses showed a significant difference of (P = 0.02) between the number of mosquito species collected in the palettes at ground level and the number collected at the height of 3 m. Cluster analysis of species abundance showed that the eggs collected in the palettes at ground level were more abundant than those collected in the palettes at the height of 3 m. We detected co-occurrence of species in the oviposition palettes; according to the null model, such species distribution was not random. Conclusions The exploitation of oviposition sites by mosquito species can represent an event forced by population density facilitated by the ecological valence of individuals of one species. Understanding the aggregate distribution of larvae at the oviposition site allows us to conduct more in-depth studies of the oviposition behavior of female mosquitoes. Graphical Abstract

Plži přírodní rezervace Poledňana v CHKO Beskydy [Gastropods of the Poledňana Nature Reserve in the Beskydy PLA]

The Poledňana Nature Reserve is located in the northeastern part of the Beskydy PLA, close to Staré Hamry town. The subject of protection are old growth forests with natural-like tree composition. During the survey in 2021, 43 species (42 terrestrial and one aquatic) of gastropods were recorded. The species composition consists predominantly of woodland dwellers (28 spp.; 65%) followed by eurytopic (5; 12%), hygrophilous woodland dwellers (4; 12%), hygrophilous (3; 7%), strongly hygrophilous (1; 2%) and one (2%) aquatic species. Endangered Bulgarica cana, indicating high conservation value of local forest fragment, vulnerable Daudebardia brevipes, Eucobresia nivalis, Vitrea transsylvanica, nearly threatened Bielzia coerulans, Bythinella austriaca and Vestia turgida are species of conservation importance. There is need to preserve non-interventional regime in the most valuable parts to retain and to establish favorable habitat conservation status. The tree composition in spruce-dominated areas should be gradually changed towards natural composition.

Nesting Biology of the Solitary Ground-Nesting Bee Diadasina riparia (Apidae: Emphorini)

We described the nesting behavior and ecology of Diadasina riparia, from an urban dry forest fragment. The nests of D. riparia were shallow with circular entrance, closed by a mud plug, from which a straight vertical tunnel ending in one or more brood cells. Most females need one day for construction and provisioning the nest. The natural enemies were flies of Anthrax genus, the cleptoparasitic bees Leiopodus trochantericus, and Mutillidae wasp. The feature about the life history, nest architecture, materials used, pollen provisions behavior and associated organisms of this species allow the comparison with other emphorines species.