Influence of multi-scale landscape structure on the occurrence of carnivorous mammals in a human-modified savanna, Brazil

São Paulo is the most developed state in Brazil and contains few fragments of native ecosystems, generally surrounded by intensive agriculture lands. Despite this, some areas still shelter large native animals. We aimed at understanding how medium and large carnivores use a mosaic landscape of forest/savanna and agroecosystems, and how the species respond to different landscape parameters (percentage of landcover and edge density), in a multi-scale perspective. The response variables were: species richness, carnivore frequency and frequency for the three most recorded species (Puma concolor, Chrysocyon brachyurus and Leopardus pardalis). We compared 11 competing models using Akaike's information criterion (AIC) and assessed model support using weight of AIC. Concurrent models were combinations of landcover types (native vegetation, “cerrado” formations, “cerradão” and eucalypt plantation), landscape feature (percentage of landcover and edge density) and spatial scale. Herein, spatial scale refers to the radius around a sampling point defining a circular landscape. The scales analyzed were 250 (fine), 1,000 (medium) and 2,000 m (coarse). The shape of curves for response variables (linear, exponential and power) was also assessed. Our results indicate that species with high mobility, P. concolor and C. brachyurus, were best explained by edge density of the native vegetation at a coarse scale (2,000 m). The relationship between P. concolor and C. brachyurus frequency had a negative power-shaped response to explanatory variables. This general trend was also observed for species richness and carnivore frequency. Species richness and P. concolor frequency were also well explained by a second concurrent model: edge density of cerradão at the fine (250 m) scale. A different response was recorded for L. pardalis, as the frequency was best explained for the amount of cerradão at the fine (250 m) scale. The curve of response was linearly positive. The contrasting results (P. concolor and C. brachyurus vs L. pardalis) may be due to the much higher mobility of the two first species, in comparison with the third. Still, L. pardalis requires habitat with higher quality when compared with other two species. This study highlights the importance of considering multiple spatial scales when evaluating species responses to different habitats. An important and new finding was the prevalence of edge density over the habitat extension to explain overall carnivore distribution, a key information for planning and management of protected areas.     

Reproduction and Activity of the Snail-Eating Snake,Dipsas albifrons (Colubridae), in the Southern Atlantic Forest in Brazil

A study in a remnant of cerrado vegetation in São Paulo State, Brazil, was carried out to investigate the possible role of leaf-cutting ants in the creation of nutrient-rich patches and their consequent influence on plant establishment and growth. The results showed that leaf-cutting ants had neither detectable effect on local nutrient enrichment nor on plant community structure. It is suggested that leaf-cutting ants may affect early successional stages of the vegetation, when colonies are more abundant and disperse into the habitat. Foi feito um estudo em um remanescente de vegetação de cerrado no Estado de São Paulo, com o objetivo de testar o papel das sa£vas na criação de manchas ricas em nutrientes e sua conseqüente influência no estabelecimento e crescimento das plantas. Os resultados mostraram que as saúvas não tiveram nenhum efeito detectável no enriquecimento local de nutrientes e nem na estrutura das comunidades vegetais. Sugere-se que as saúvas possam afetar os estádios iniciais da sucessão vegetal, quando as colônias são mais abundantes e dispersam-se mais no habitat.     

Changes in the plant community of a Brazilian grassland savannah after 22 years of invasion by Pinus elliottii Engelm

Abstract

Background: The invasion by Pinus elliottii is one of the most serious threats to the remaining native cerrado vegetation in São Paulo State, Brazil, causing biodiversity losses yet to be evaluated. We conducted a study in an area where P. elliottii began establishing in 1988.

Aims: To estimate diversity losses in the plant community and to understand the floristic and structural changes resulting from pine tree invasion of grassland savannah.

Methods: All plants taller than 50 cm were sampled in 35 plots (64 m² each) within an area densely invaded by P. elliottii and in 10 plots in non-invaded grassland savannah. Density, species richness, diversity, ground cover and spatial distribution were compared by Wilcoxon tests, non-metric multidimensional scaling and Payandeh indices.

Results: Twenty-two years after the arrival of the first invasive trees (founders), the grassland savannah has become a dense pine forest with 12,455 individuals ha^?1, a basal area of 26.44 m² ha^?1, a sparse native woody understory comprised of 16 species (H'?=?0.44), density of 1210 individuals ha^?1 and the herbaceous layer totally absent.

Conclusions: Invasion by Pinus elliottii has completely changed the structure of the grassland savannah and caused severe plant diversity losses. Native species surviving the invasion in the understory do not typically represent the previous composition and functional traits of the native vegetation.     

Alien grasses in Brazilian savannas: a threat to the biodiversity

African grasses used as forage are spreading fast in cerrado (Brazilian savanna) patches, probably displacing native species. An analysis of the graminoid species abundance was performed in Cerrado Pé-de-Gigante Reserve (São Paulo State, Brazil), where their relative frequency, density, dominance and the value of importance were assessed in two cerrado forms: cerrado sensu stricto (denser) and campo cerrado (open). Thirty-six transects were determined, along which 3240.5 m × 0.5 m herbaceous samples were taken. Ordination by CCA analysis was performed to detect gradients in the graminoid species distribution, according to shading, distance from the reserve border and aspect. Interspecific associations among the species were tested. A total of 93 species were sampled, predominantly Poaceae and Myrtaceae families. Two alien grasses were found, Melinis minutiflora and Brachiaria decumbens, with very high values of importance. Light availability proved to be the most important analyzed environmental factor related to graminoid distribution, strongly correlated with the abundance of M. minutiflora. Both alien grasses were negatively associated with most native graminoids, suggesting they exert a strong competitive pressure on the native herbaceous community. Attention must be taken to the introduction of alien species in the country.     

On the need of legal frameworks for assessing restoration projects success: new perspectives from São Paulo state (Brazil)

Despite growing worldwide commitment to large‐scale ecosystem restoration, national public policies on restoration are few, and those that exist tend to be vague. Brazil and especially São Paulo state stand out. In a pioneering attempt to improve restoration projects and their outcomes, the Secretariat for the Environment of the State of São Paulo has enacted a legal instrument to drive planning and to assess whether the goals and targets of mandatory ecological restoration are being achieved. Regardless of the restoration techniques applied, the effectiveness of mandatory or public‐funded projects will henceforth be assessed by using three ecological indicators: (1) ground coverage with native vegetation; (2) density of native plants spontaneously regenerating; and (3) number of spontaneously regenerating native plant species. We analyze how this science‐based legal framework is expected to promote greater restoration success, improve cost‐effectiveness, and help bridge the all‐too‐familiar knowledge‐action gap in environmental policies. Notably, scientists, professionals, public agents, and stakeholders from different institutions have collaborated to advance the refinement and rolling out of this legal instrument. By 2037, it is expected that more than 300,000 restoration projects will be carried out in São Paulo state and monitored using this set of indicators. We also suggest that this approach could be usefully applied to the growing number of ecological restoration programs being carried out worldwide, especially in the context of offset policies intended to achieve serious compensation for environmental degradation or loss of biodiversity.     

Edge influence on plant litter biomass in forest and savanna in the Brazilian cerrado

Edge influence, characterized by differences in ecosystem characteristics between the edge and the interior of remnants in fragmented landscapes, affects a variety of organisms and ecosystem processes. An important feature that may be affected by edges is the amount of plant litter, which provides important habitat for a large variety of organisms and influences ecological processes such as fire dynamics. We studied edge influence on plant litter and fine woody debris in the cerrado of São Paulo state, south‐eastern Brazil. We collected, sorted, dried and weighed plant litter along 180 m‐long transects perpendicular to three savanna and eleven forest edges adjacent to different anthropogenic land uses, with four to five transect per edge. There tended to be less biomass of the finer portions of fine woody debris at both savanna and forest edges. Graminoid litter at savanna edges was greater than in the corresponding interior areas, whereas other litter portions were either unaffected by edges or did not show consistent patterns in either savanna or forest. Edge influence was usually restricted to the first 20 m from the edge, was not influenced by edge characteristics and exhibited no clear differences between savanna and forest areas. Several mechanisms may have led to the variable patterns observed including variation in the plant community, plant architecture, and invasive species. The edge‐related variation in plant litter may putatively lead to, for example, increased fire frequency and intensity at the savanna edges and altered trophic dynamics at forest edges; the mechanisms and consequences of this edge influence should be addressed in future studies.     

The same old mistakes in aquaculture: the newly-available striped catfish <Emphasis Type="Italic">Pangasianodon hypophthalmus</Emphasis> is on its way to putting Brazilian freshwater ecosystems at risk

In the state of São Paulo in southeastern Brazil, a dangerous decree allows the culture of hybrids and non-native extralimital fish species in the Paraná and East Atlantic River basins. We recorded the illegal importation and sale of the non-native striped catfish Pangasianodon hypophthalmus in northeastern, central-western, southeastern, and southern areas of the country. This species is already consumed across Brazil and is cultivated for ornamental purposes. Besides escapes from fish farms and ‘fish and pays’, P. hypophthalmus can reach natural environments through aquarium dumping and ornamental ponds, motivated by its large size that reach after being sold at small size. The species has been introduced in many countries, and if established in Brazil, could put native Brazilian biodiversity and ecosystems at risk. Although importing specimens of P. hypophthalmus is prohibited by law, Decree 62.243/2016 in the state of São Paulo creates a new opportunity for invasion. In fact, once a novel fish species is moved to a new continent, it is irrational to supposed that it will stay static just in the area for which it was intended. In general, the fish disperse in the novel area on their own, by escapes from captivity or deliberate and illicit releases by persons or associations. The unwise attitude of Brazilian decision-makers and lay people in their attempt to develop aquaculture with non-native species goes against the objectives of responsible aquaculture based in native species.     

Evolutionary history of Scinax treefrogs on land‐bridge islands in south‐eastern Brazil

Aim We investigated how Pleistocene refugia and recent (c. 12,000 years ago) sea level incursions shaped genetic differentiation in mainland and island populations of the Scinax perpusillus treefrog group. Location Brazilian Atlantic Forest, São Paulo state, south‐eastern Brazil. Methods Using mitochondrial and microsatellite loci, we examined population structure and genetic diversity in three species from the S. perpusillus group, sampled from three land‐bridge islands and five mainland populations, in order to understand the roles of Pleistocene forest fragmentation and sea level incursions on genetic differentiation. We calculated metrics of relatedness and genetic diversity to assess whether island populations exhibit signatures of genetic drift and isolation. Two of the three island populations in this study have previously been described as new species based on a combination of distinct morphological and behavioural characters, thus we used the molecular datasets to determine whether phenotypic change is consistent with genetic differentiation. Results Our analyses recovered three distinct lineages or demes composed of northern mainland São Paulo populations, southern mainland São Paulo populations, and one divergent island population. The two remaining island populations clustered with samples from adjacent mainland populations. Estimates of allelic richness were significantly lower, and estimates of relatedness were significantly higher, in island populations relative to their mainland counterparts. Main conclusions Fine‐scale genetic structure across mainland populations indicates the possible existence of local refugia within São Paulo state, underscoring the small geographic scale at which populations diverge in this species‐rich region of the Atlantic Coastal Forest. Variation in genetic signatures across the three islands indicates that the populations experienced different demographic processes after marine incursions fragmented the distribution of the S. perpusillus group. Genetic signatures of inbreeding and drift in some island populations indicate that small population sizes, coupled with strong ecological selection, may be important evolutionary forces driving speciation on land‐bridge islands.     

Obituaries

Background: Although impacts of edge effects on forest ecosystems are well known, their consequences on savannas have rarely been explored.

Aims: To investigate the influence of edge effects on the plant community and microclimate of a cerrado fragment in south-eastern Brazil.

Methods: Several plant community variables (density, basal area, richness and cover by each vegetation layer) and microclimatic variables (light, air temperature and humidity), were measured in 10 transects across a savanna fragment surrounded by exotic grasses, and were used to fit semi-parametric models relating these variables with the distance from the habitat edge.

Results: Differences in microclimate and tree communities were poorly related to distance from the edge. On the other hand, there were detectable edge effects on the ground layer community (i.e. plants less than 50 cm in height). Edges had a negative effect on native plants of this layer (density and richness of all species and cover of native grasses), while favouring invasive grasses.

Conclusions: Unlike reports for edge effects in forest ecosystems, microclimate does not explain changes in this cerrado fragment. The most significant edge effect threatening the conservation of cerrado vegetation is the widespread invasion by African grasses. Starting from the fragment borders, this invasion causes changes in the structure and composition of the native plant community, thus jeopardising the population dynamics and persistence of native species.     

Assessment of the nursery species pool for restoring landscapes in southeastern Brazil

Brazil has committed to fulfilling international restoration goals and to enforcing environmental legislation that will require private landowners to undertake ecological restoration of 21 million hectares of degraded and deforested landscapes. To support a broad range of restoration practices, a well‐established supply chain capable of representing regional plant diversity is essential. This study investigated the restoration species pool in native plant nurseries in São Paulo state, located in southeastern Brazil, and evaluated their geographic distribution, similarity of their plant stocks, and the proportion of species represented from regional floras. Despite a lack of technical assistance and a significant presence of nonnative species (126 species, average 7.5 species/nursery), we found an impressive native species richness in plant nurseries (561 species, average 86.4 species/nursery) from both the Atlantic Forest and Cerrado domains, representing 38–44% of regional floras. There was a huge bias toward tree and shrub species (96.6%) and an absence or underrepresentation of other growth forms, as well as of savanna specialists, animal‐dispersed, and threatened species. The dissimilarity of species observed among the different nurseries surveyed highlights their role in representing regional diversity, which reflects their regional seed collection practices. Effective assistance and training are essential to address issues related to misidentification of species, underrepresentation of most functional plant groups, and the presence of nonnative species, as well as to support the supply chain, which is currently undergoing a market downturn.     

Mite (Acari; Arachnida) diversity of two native plants in fragments of a semideciduous seasonal forest in Brazil

Studies to determine mite species richness in natural environments are still scarce, and have been conducted mainly in tropical ecosystems. The aim of this study was to determine the species richness of mites on two common native plants in fragments of the semideciduous seasonal forest in the Northwest of São Paulo State, Brazil. In each of eight fragments, 10 specimens of Actinostemon communis (Euphorbiaceae) and 10 of Trichilia casaretti (Meliaceae) were selected and marked. In total, 124 species of mites belonging to 21 families were found on the two plants. Tarsonemidae had the highest diversity (34 species), followed by Phytoseiidae (31), Tetranychidae (9) and Tenuipalpidae (8). Species accumulation curves for the two sampled plants did not reach an asymptote, even with the large sampling effort. Hence, it is estimated that a greater sampling effort may lead to an increase in species richness compared with what was found in this study. The richness of this mite fauna suggests that preservation of these plant species is important to maintain the mite diversity in these forest fragments.     

A new species of <Emphasis Type="Italic">Vanilla</Emphasis> (Orchidaceae: Vanilloideae) from São Paulo,Brazil

A new orchid species, Vanilla paludosa, native to marshy forests close to cerrado vegetation in the state of São Paulo, Brazil, is described and illustrated. The relationship of V. paludosa to other species of the genus is discussed.     

Lopesia leandrae (Diptera,Cecidomyiidae), a new species of gall midge associated with Leandra ionopogon (Mart.) Cogn. (Melastomataceae), a native plant to Brazil

Lopesia leandrae (Diptera, Cecidomyiidae), a new galling species associated with Leandra ionopogon (Melastomataceae), a native plant species to Brazil, is described based on larva, pupal exuvia, male and female. L. leandrae galls were collected in an area of Atlantic Forest in Bertioga, state of São Paulo, Southeastern Brazil. The new species was compared to the other species of Lopesia.     

Hurricane wrack generates landscape‐level heterogeneity in coastal pine savanna

Wrack (vegetation debris) deposited by storm surges of major hurricanes along the northern Gulf of Mexico produces depressant effects that vary from partial to complete mortality of groundcover vegetation in coastal savannas. As wrack decomposes or is relocated by a subsequent hurricane, patches are opened to colonization. We postulated that patterns of wrack deposition and removal, coupled with differential responses by savanna plant species should produce alternate states of groundcover vegetation. We explored extreme effects of wrack deposited by Hurricane Katrina (2005) in savannas dominated by slash pine Pinus elliottii and cordgrass Spartina patens and located above mean high tide at the Grand Bay National Estuarine Research Reserve, Mississippi, USA. In 2008, we established plots in adjacent areas with and without wrack deposits. Almost no groundcover plant species occurred in wrack deposits compared to adjacent groundcover without wrack. We simulated redistribution of wrack during a new storm surge by removing wrack from replicated plots and depositing it in plots without wrack, recording plant species in treatment and control plots before, then one month and one year after manipulations. One year later, about half the species present before wrack addition (especially dominant graminoids) grew back through redistributed wrack, suggesting that some species were resistant to burial of limited amounts of wrack. Wrack removal resulted in germination and establishment of numerous herbaceous plant species not in undisturbed groundcover, doubling total aboveground numbers of species in the pine savanna and shifting groundcover communities to alternate states not present prior to Katrina. Removal of wrack opens space colonized by resilient species, including those transported in wrack and those surviving intervals between disturbances belowground. Wrack dynamics (deposition and removal) generated alternate states that resulted from resistance‐ and resilience‐driven changes in different patches of groundcover in coastal savannas.     

Biodiversity responses to land‐use and restoration in a global biodiversity hotspot: Ant communities in Brazilian Cerrado

Given that land‐use change is the main cause of global biodiversity decline, there is widespread interest in adopting land‐use practices that maintain high levels of biodiversity, and in restoring degraded land that previously had high biodiversity value. In this study, we use ant taxonomic and functional diversity to examine the effects of different land uses (agriculture, pastoralism, silviculture and conservation) and restoration practices on Cerrado (Brazilian savanna) biodiversity. We also examine the extent to which ant diversity and composition can be explained by vegetation attributes that apply across the full land management spectrum. We surveyed vegetation attributes and ant communities in five replicate plots of each of 13 land‐use and restoration treatments, including two types of native vegetation as reference sites: cerrado sensu stricto and cerradão. Several land‐use and restoration treatments had comparable plot richness to that of the native reference habitats. Ant species and functional composition varied systematically among land‐use treatments following a gradient from open habitats such as agricultural fields to forested sites. Tree basal area and grass cover were the strongest predictors of ant species richness. Losses in ant diversity were higher in land‐use systems that transform vegetation structure. Among productive systems, therefore, uncleared pastures and old pine plantations had similar species composition to that occurring in cerrado sensu stricto. Restoration techniques currently applied to sites that were previously Cerrado have focused on returning tree cover, and have failed to restore ant communities typical of savanna. To improve restoration outcomes for Cerrado biodiversity, greater attention needs to be paid to the re‐establishment and maintenance of the grass layer, which requires frequent fire. At the broader scale, conservation planning in agricultural landscapes, should recognize the value of land‐use mosaics and the risks of homogenization.     

A new species of Cyclopogon (Orchidaceae: Spiranthinae) from São Paulo, Brazil

Cyclopogon carinianus, a new orchid species native to seasonal semideciduous forests in the State of São Paulo, Brazil, is described and illustrated. The relationship of C. carinianus to other taxa of the genus is discussed, and comments on their geographical distribution, ecology, and conservation status are provided.     

Using plant functional types to compare vegetation structure of alien-invaded and uninvaded Acacia nilotica savannas

Four plant functional types (PFTs) were used to compare the vegetation structure of an alien-invaded Acacia nilotica savanna with one of negligible invasions. Heights, canopy covers and species richness of three native PFTs (woody plants, grasses and herbs) and one alien PFT (woody plants) were measured in 14, 1-m² quadrats sampled in a stratified-random pattern in a 400-m² plot demarcated in each savanna. In the uninvaded plot, mean heights of native PFTs were stratified. In the invaded plot, the mean height of aliens extended into the native woody stratum with the lower range of native woody PFT heights reduced to the grass stratum. Discriminant analysis of canopy covers and species richness of the four PFTs revealed significant differences in composition between plots with the alien PFT being the most important variable correlated with these differences. Univariate analysis confirmed the dominance of alien woody plants in the invaded plot but also showed significant reductions in the canopy covers and species richness of native herbs and grasses compared to those in the uninvaded plot. These results suggest that PFTs can rapidly measure small-scale, spatial differences in the physiognomy, composition and species richness of A. nilotica savannas when invaded by alien woody plants.     

Savannas after afforestation: Assessment of herbaceous community responses to wildfire versus native tree planting

Afforestation and fire exclusion are pervasive threats to tropical savannas. In Brazil, laws limiting prescribed burning hinder the study of fire in the restoration of Cerrado plant communities. We took advantage of a 2017 wildfire to evaluate the potential for tree cutting and fire to promote the passive restoration of savanna herbaceous plant communities after destruction by exotic tree plantations. We sampled a burned pine plantation (Burned Plantation); a former plantation that was harvested and burned (Harvested & Burned); an unburned former plantation that was harvested, planted with native trees, and treated with herbicide to control invasive grasses (Native Tree Planting); and two old-growth savannas which served as reference communities. Our results confirm that herbaceous plant communities on post-afforestation sites are very different from old-growth savannas. Among post-afforestation sites, Harvested & Burned herbaceous communities were modestly more similar in composition to old-growth savannas, had slightly higher richness of savanna plants (3.8 species per 50-m²), and supported the greatest cover of native herbaceous plants (56%). These positive trends in herbaceous community recovery would be missed in assessments of tree cover: whereas canopy cover in the Harvested & Burned site was 6% (less than typical of savannas of the Cerrado), the Burned Plantation and Native Tree Planting supported 34% and 19% cover, respectively. By focusing on savanna herbaceous plants, these results highlight that tree cutting and fire, not simply tree planting and fire exclusion, should receive greater attention in efforts to restore savannas of the Cerrado.     

A new species of Campomanesia (Myrtaceae) from southeastern Brazil

Campomanesia simulans, a new species from the states of São Paulo and Minas Gerais, Brazil, is described and illustrated.     

Miconia atlantica, a new species of Melastomataceae from the eastern mountains of Brazil

A new species of Miconia from the mountains in the Atlantic Forest of eastern Brazil is presented here. Miconia atlantica has been collected in the states of São Paulo and Espírito Santo. It belongs to section Glossocentrum and can be recognized among others species in this section by the leaves with acute bases, an indumentum consisting of stellate trichomes moderately covering the abaxial surface of mature leaves, glomerulate inflorescences, and stamens with unappendaged connectives. Marsupiform domatia were found in São Paulo populations.