Distinct carbon sources indicate strong differentiation between tropical forest and farmland bird communities

The conversion of forest into farmland has resulted in mosaic landscapes in many parts of the tropics. From a conservation perspective, it is important to know whether tropical farmlands can buffer species loss caused by deforestation and how different functional groups of birds respond to land-use intensification. To test the degree of differentiation between farmland and forest bird communities across feeding guilds, we analyzed stable C and N isotopes in blood and claws of 101 bird species comprising four feeding guilds along a tropical forest-farmland gradient in Kenya. We additionally assessed the importance of farmland insectivores for pest control in C4 crops by using allometric relationships, C stable isotope ratios and estimates of bird species abundance. Species composition differed strongly between forest and farmland bird communities. Across seasons, forest birds primarily relied on C3 carbon sources, whereas many farmland birds also assimilated C4 carbon. While C sources of frugivores and omnivores did not differ between forest and farmland communities, insectivores used more C4 carbon in the farmland than in the forest. Granivores assimilated more C4 carbon than all other guilds in the farmland. We estimated that insectivorous farmland birds consumed at least 1,000 kg pest invertebrates km−2 year−1. We conclude that tropical forest and farmland understory bird communities are strongly separated and that tropical farmlands cannot compensate forest loss for insectivorous forest understory birds. In tropical farmlands, insectivorous bird species provide a quantitatively important contribution to pest control.

Effects of forest management on bryophyte communities on deadwood

Epixylic bryophytes are important components of forest vegetation but are currently endangered by increment of wood harvest and intensive forest management. In this paper we present a study about the relationship between forest management, deadwood abundance, deadwood attributes and species richness of epixylic bryophytes on 30 plots comprising three forest types (managed coniferous, managed deciduous and unmanaged deciduous forests) in three regions in Germany. Additionally we analyzed the relations between deadwood attributes (wood species, decay, deadwood type, size) and bryophytes on deadwood items (n = 799) and calculated species interaction networks of wood species and bryophytes. Overall, species richness of epixylic bryophytes was positively related to deadwood abundance and diversity. The mean deadwood abundance was lowest in unmanaged forests (9.7 m³ ha^-1) compared with 15.0 m³ ha^-1 in managed deciduous and 25.1 m³ ha^-1 in managed coniferous forests. Accordingly, epixylic bryophyte species richness per plot increased from 7 species per 400 m 2 in unmanaged, 10 in managed deciduous and 16 in managed coniferous forests. The interaction network provided evidence of importance of tree-species diversity for bryophyte diversity and the relevance of particular wood species for rare bryophytes.

Generally, the results demonstrate a considerable lack of deadwood in all forest types, even in unmanaged forests. Species richness of epixylic bryophytes was strongly limited by available substrates within the observed deadwood abundance ranging up to only 60 m³ ha^-1. Altogether, this suggests a high demand to increase both abundance and diversity of deadwood in forests.

Higher temporal variability of forest breeding bird communities in fragmented landscapes

Understanding the relationship between animal community dynamics and landscape structure has become a priority for biodiversity conservation. In particular, predicting the effects of habitat destruction that confine species to networks of small patches is an important prerequisite to conservation plan development. Theoretical models that predict the occurrence of species in fragmented landscapes, and relationships between stability and diversity do exist. However, reliable empirical investigations of the dynamics of biodiversity have been prevented by differences in species detection probabilities among landscapes. Using long-term data sampled at a large spatial scale in conjunction with a capture-recapture approach, we developed estimates of parameters of community changes over a 22-year period for forest breeding birds in selected areas of the eastern United States. We show that forest fragmentation was associated not only with a reduced number of forest bird species, but also with increased temporal variability in the number of species. This higher temporal variability was associated with higher local extinction and turnover rates. These results have major conservation implications. Moreover, the approach used provides a practical tool for the study of the dynamics of biodiversity.

New forest frontiers : for jobs, permanent communities, a stronger nation.

Chiefly illustrations.

Seasonal change of oribatid mite communities (Acari, Oribatida) in three different types of microhabitats in an oak forest

Oribatid mites are one of the most abundant groups of the ground-dwelling mesofauna. They can be found in almost every terrestrial habitat all over the world and they are characterized by great species richness and great number of individuals. In spite of that not enough is known about their behaviour on community level and their spatial and temporal pattern in different habitats of the world. In our present study the seasonal behaviour of oribatid mite communities was analysed in three types of microhabitats in a temperate deciduous forest: in leaf litter, soil and moss. Samples were collected at a given site in a year and a half and the oribatid mite communities living there were studied on genus level along with the changes of meteorological factors characteristic of the area. The results show that corresponding to similar previous researches, the communities in our study do not have a seasonally changing, returning pattern either. Based on this, we can conclude that climatic differences and differences in other seasonally changing factors between the seasons do not have a significant role in the annual change of communities. Besides that we discovered that the communities of the three microhabitats are not completely the same. It is the oribatid mite community of the moss which differs mostly from communities in the leaf litter and in the soil. Our study calls attention among others to the fact that compositional changes of the oribatid mite communities living all over the world and their causes are unclear to date.

INTERACTIVE EFFECTS OF CLIMATE CHANGE AND FUNGAL COMMUNITIES ON THE DECOMPOSITION OF WOOD-DERIVED CARBON IN FOREST SOILS

Soils are the largest sinks of carbon in terrestrial ecosystems. Soil organic carbon is important for ecosystem balance as it supplies plants with nutrients, maintains soil structure, and helps control the exchange of CO2 with the atmosphere. The processes in which wood carbon is stabilized and destabilized in forest soils is still not understood completely. This study attempts to measure early wood decomposition by different fungal communities (inoculation with pure colonies of brown or white rot, or the original microbial community) under various interacting treatments: wood quality (wood from +CO2, +CO2+O3, or ambient atmosphere Aspen-FACE treatments from Rhinelander, WI), temperature (ambient or warmed), soil texture (loamy or sandy textured soil), and wood location (plot surface or buried 15cm below surface). Control plots with no wood chips added were also monitored throughout the study. By using isotopically-labelled wood chips from the Aspen-FACE experiment, we are able to track wood-derived carbon losses as soil CO2 efflux and as leached dissolved organic carbon (DOC). We analyzed soil water for chemical characteristics such as, total phenolics, SUVA254, humification, and molecular size. Wood chip samples were also analyzed for their proportion of lignin:carbohydrates using FTIR analysis at three time intervals throughout 12 months of decomposition. After two years of measurements, the average total soil CO2 efflux rates were significantly different depending on wood location, temperature, and wood quality. The wood-derived portion soil CO2 efflux also varied significantly by wood location, temperature, and wood quality. The average total DOC and the wood-derived portion of DOC differed between inoculation treatments, wood location, and temperature. Soil water chemical characteristics varied significantly by inoculation treatments, temperature, and wood quality. After 12 months of decomposition the proportion of lignin:carbohydrates varied significantly by inoculation treatment, with white rot having the only average proportional decrease in lignin:carbohydrates. Both soil CO2 efflux and DOC losses indicate that wood location is important. Carbon losses were greater from surface wood chips compared with buried wood chips, implying the importance of buried wood for total ecosystem carbon stabilization. Treatments associated with climate change also had an effect on the level of decomposition. DOC losses, soil water characteristics, and FTIR data demonstrate the importance of fungal community on the degree of decomposition and the resulting byproducts found throughout the soil.

The flora and communities Carnaubal Palm Forest in the northern region of Ceará - Brazil

The “dicótilo-palmácea” mixed forest is found in the fluvial plains (floodplains) of watercourses on the Ceará semiarid region (Brazil), distinguishing from the surrounding vegetation (caatinga) by the prevalence of larger tree species. In the river’s margins, presenting high variability in the extension of the riverbanks, arise floodplains in pedologic complexes mainly composed by neossols and argissols, resulting from the deposition of sediments. In these areas of high fertility soils and subjected to flooding during part of the year, it develops a particular type of riparian vegetation dominated by carnauba palm tree (Copernicia prunifera (Mill.) H.E. Moore) forming a particular type of riparian forest, designated by carnaubal palm forest. We aimed to carry out floristic and phytosociological surveys of carnauba palm forests located in the northern region of Ceará. The classical sigmatist method of Braun-Blanquet was applied and classification analysis (Twinspan) was perfomed. The field work occurred in March 2014 and 2016 in eight areas: Fazenda Pedra Branca (03º 37’ 10’’ S e 40º 18’ 30’’ W, 104 m asl), Vale do Rio Bom Jesus (04º 04’ 42’’ S e 39º 57’ 08’’ W, 200 m asl), Lagoa do Peixe (03º 56’ 28’’ S e 40º 23’ 23’’ W, 97 m asl), Fazenda Peixes (04º 06’ 03’’ S e 40º 32’ 43’’ W, 114 m asl), Fazenda Natividade (04º 02’ 50’’ S e 40º 29’ 03’’ W, 109 m asl), Fazenda Morro Alto (02º 53’ 42’’ S e 39º 54’ 51’’ W, 16 m asl), Fazenda Araticum (03º 04’ 58’’ S e 40º 09’ 36’’ W, 19 m asl) and Fazenda Experimental da UVA (03º 37' 04'' S 40º 18' 18'' W, 200 m asl).The floristic list consists of 170 species, distributed between 127 genera and 50 families. Twenty-seven Brazilian endemic species were identified, from which 8 are exclusive of the Caatinga biome. The Fabaceae was the most representative family, with the highest number of species (28), followed by Poaceae (17), Malvaceaea (14), Euphorbiaceae (12), Asteraceaea (9), Convolvulaceae and Rubiaceae (9). The dominant life forms were therophytes (34%), phanerophytes (30%) and chamaephytes (18%). Two communities were identified as a result of the classification analysis using the Twinspan.

The influence of forest management on bird communities of portuguese montados

The world distribution of cork oak Quercus suber and holm oak Q. rotundifolia is basically restricted to the western Mediterranean basin. These two evergreen oaks are the base of the Portuguese montado and the Spanish dehesa. This thesis aims to analyse how bird communities of the montado are influenced by management practices. We used different approaches to study this relationship, and to evaluate which features are responsible for species distribution in different typologies of montado. First, we reviewed the concept of montado in order to better understand the system and to set thresholds on what can be considered as montado. Afterwards, we studied the elements that promote higher species diversity and individual species, or group of species, that can act as indicators of High Nature Value for montados. Finally, we evaluated how the bird communities are structured, and the influence of the main management actions (e.g. cattle and cork exploitation) on those communities; Resumo: A distribuição mundial do sobreiro Quercus suber e da azinheira Quercus rotundifolia é praticamente restrita à bacia do Mediterrâneo. Estas duas espécies de carvalhos são a base dos montados em Portugal e das dehesas em Espanha. No âmbito desta tese analisamos como as comunidades de aves do montado são influenciadas pela gestão florestal. Para este efeito usámos diferentes abordagens e avaliámos quais as características do montado responsáveis pela distribuição das espécies ao longo das suas diferentes tipologias. Fizemos uma revisão do conceito de montado e proposemos uma definição para o sistema, englobando a sua multifuncionalidade. Estudámos os elementos singulares que promovem a diversidade de aves e que podem ser simultaneamente indicadores de áreas de Alto Valor Natural (HNV). Por fim, avaliámos qual a influência da gestão (p. ex. pastoreio e descortiçamento) na estruturação das comunidades de aves.

Tree structure and richness in an Atlantic Forest fragment: distance from anthropogenic and natural edges

Approximately 7.2% of the Atlantic rainforest remains in Brazil, with only 16% of this forest remaining in the State of Rio de Janeiro, all of it distributed in fragments. This forest fragmentation can produce biotic and abiotic differences between edges and the fragment interior. In this study, we compared the structure and richness of tree communities in three habitats - an anthropogenic edge (AE), a natural edge (NE) and the fragment interior (FI) - of a fragment of Atlantic forest in the State of Rio de Janeiro, Brazil (22°50'S and 42°28'W). One thousand and seventy-six trees with a diameter at breast height > 4.8 cm, belonging to 132 morphospecies and 39 families, were sampled in a total study area of 0.75 ha. NE had the greatest basal area and the trees in this habitat had the greatest diameter:height allometric coefficient, whereas AE had a lower richness and greater variation in the height of the first tree branch. Tree density, diameter, height and the proportion of standing dead trees did not differ among the habitats. There was marked heterogeneity among replicates within each habitat. These results indicate that the forest interior and the fragment edges (natural or anthropogenic) do not differ markedly considering the studied parameters. Other factors, such as the age from the edge, type of matrix and proximity of gaps, may play a more important role in plant community structure than the proximity from edges.

A comparison of the leaf-litter ant fauna in a secondary atlantic forest with an adjacent pine plantation in southeastern Brazil

We investigated the influence of Pinus afforestation on the structure of leaf-litter ant communities in the southeastern Brazilian Atlantic Forest, studying an old secondary forest and a nearly 30 year-old never managed Pinus elliottii reforested area. A total of 12,826 individual ants distributed among 95 species and 32 genera were obtained from 50 1 m² samples/ habitat. Of these, 60 species were recorded in the pine plantation and 82 in the area of Atlantic forest; almost 50% of the species found in the secondary forest area were also present in the pine plantation. The number of species per sample was significantly higher in the secondary forest than in the pine plantation. Forest-adapted taxa are the most responsible for ant species richness differences between areas, and the pine plantation is richer in species classified as soil or litter omnivorous-dominants. The specialized ant predators registered in the pine plantation, as seven Dacetini, two Basiceros, two Attini and two Discothyrea, belong to widely distributed species. The NMDS (non-metric multidimensional scaling) ordination also suggested strong differences in similarity among samples of the two areas. Furthermore, this analysis indicated higher sample heterogeneity in the secondary forest, with two clusters of species, while in the pine plantation the species belong to a single cluster. We applied the ant mosaic hypothesis to explain the distribution of the leaf-litter fauna and spatial autocorrelation tests among samples. We argue that the results are likely related to differences in quality and distribution of the leaf-litter between the pine plantation and the secondary area.

Trap-nesting bees (Hymenoptera: Apoidea) in forest fragments of the State of Sao Paulo, Brazil

We studied the community ecology of trap-nesting bees in two forest fragments of the State of Sao Paulo, Brazil, during two years, utilizing bamboo canes and tubes made of black cardboard as trap nests. The traps were inspected once a month with an otoscope. One hundred and fifteen nests were obtained at Estacao Ecologica de Paulo de Faria, Paulo de Faria (EEPF). These included nine species belonging to five genera and two families. At Santa Cecilia Farm (SCF), 12 species belonging to seven genera and three families built 392 nests. Natural enemies reared from nests of both areas included Hymenoptera, Diptera and Coleoptera. Species richness was similar between the areas but the communities differed considerably in species composition. The higher diversity found at EEPF was due to more even distribution of the species. No difference was observed between the numbers of nests built in each year in each area. Although the species richness was lower in the cool/dry season of both years at SCF, and in the first year at EEPF, the nesting frequencies did not differ between seasons for both the overall community but for each of the most abundant species. No annual fluctuation in the frequencies of nesting was observed. As temperature and precipitation were not found to be significantly different between the two years of study in each area, we concluded that climatic stability resulted in population stability.