Differences In Floristic Composition Research Articles

Changes in floristic and vegetation structure in a chronosequence of abandoned gold-mining lands in a tropical Amazon forest

This study analyzes floristic and vegetation structure changes during forest succession after disturbances caused by small-scale gold mining in Madre de Dios (Peru). We compared the floristic and vegetation structure of a reference forest against three sites with different periods of abandonment after mining (5, 11 and 23-years). Three 20 × 60 m plots were defined on each site, and all tree species with a DBH >1 cm within the plots were inventoried. To evaluate species diversity and similarity, the Importance Value, effective numbers of species (0D, 1D, and 2D), and Chao-Jaccard similarity index were calculated. We used the Nonmetric multidimensional scaling for similarity ordination and the PERMANOVA test to evaluate differences in floristic composition. We recorded 129 tree species in the study areas and statistically significant differences between initial and intermediate stages were observed regarding floristic composition, basal area, height, and DBH. The transition from the initial successional stage to the reference forest produces an increase in basal area, species diversity, and floristic similarity. The 23-year-old stand had more species in common with the 11-year-old stand than the reference forest. Our results showed a high proportion of pioneer species and anemochory dispersal syndrome in the initial successional stages, but they decreased in later stages of the chronosequence. The floristic and structural attributes of forests throughout the chronosequence showed a fast recovery during secondary succession. After 23 years, the recovery of tree species density was 77 % of reference forest, while the relative recovery of species composition was much slower, on average 23 %. These results provide essential information to guide the selection of suitable species in ecological restoration projects after abandonment. Implementing forest restoration strategies based on reliable information to accelerate the process of vegetation succession is critical for recuperating areas degraded by gold mining at the Peruvian Amazon.

Response of vulnerable karst forest ecosystems under different fire severities in the Northern Dinaric Karst mountains (Slovenia)

BackgroundThis study deals with wildfires in marginal areas of the Mediterranean climatic and biogeographical regions (Northern Mediterranean) where fires were not common. The aim of the research was to determine the differences in floristic composition and traits at different intensities of fire damage and to analyze the changes in forest ecosystems during the wildfires that took place in the summer of 2022. The study included both the zonal forests and non-native black pine (Pinus nigra) forests. Remote sensing techniques linked to the vegetation data sampled in the field during the 2023 vegetation season, the very first season after the fires, were also used in the fire assessment.ResultsThe study confirmed that satellite data analysis, orthophoto interpretation, and on-site vegetation sampling provide equivalent information on fire severity, opening up the possibility of transferring knowledge to similar post-fire sites without field sampling in the future. TWINSPAN classification analysis divided the sampled plots into clusters based on tree species prevalence and fire severity. The diagnostic species of the clusters were calculated using a fidelity measure. Ordination revealed that the first axis on the detrended correspondence analysis (DCA) correlated with wildfire severity. Ecological conditions and strategies, life forms, chorotypes, seed dispersal classes, and regeneration traits were analyzed along this gradient. We found that post-fire sites became warmer, drier, and lighter, which favored the growth of ruderal, theropytic, cosmopolitan, anemochorous and post-fire emergent species. After the fire, a “wave” of annual ruderal species was observed.ConclusionsThe results indicate that post-fire recovery can be left to natural processes without human intervention, except in the case of non-native pine stands where planting or seeding may be necessary. Otherwise, it is essential to control the possible occurrence of invasive species. Isolated adaptations of species to fire have also been observed, such as heat-stimulated germination. Such adaptations could develop in regions exposed to frequent fires and where fires act as an evolutionary factor.

Impacts of climate change on semi-natural alpine pastures productivity and floristic composition

Climate change impact on pasture floristic composition needs to be carefully assessed, given its key role for the resilience of pastoral systems and related ecosystem services. Nevertheless, variations in floristic composition are rarely taken into account in climate change impact studies. Here, we used the plant community model CoSMo to simulate future dynamics of biomass accumulation and floristic composition for high-altitude semi-natural alpine pastures. Dedicated multi-site field activities were conducted to collect data for model calibration. Simulations were run for four 20-year climate scenarios centered on 2040, resulting from the combination of two general circulation models (GISS-ES and HadGEM2) and two representative concentration pathways (RCP4.5 and RCP8.5). Results highlighted the capability of CoSMo to successfully reproduce the productivity and floristic composition of semi-natural pastures, modeling efficiency and R2 being higher than 0.90 for aboveground biomass accumulation and relative abundance of species. CoSMo simulated an overall positive effect of increasing temperatures on pasture productivity (+ 10.7% on average), due to higher biomass accumulation rates and longer growing seasons. However, these benefits were highly heterogeneous among the monitored pastures (ranging from − 2.5 to + 16.2%), because of differences in floristic composition and in species-specific thermal requirements that led to complex, non-linear reactions to climate variations. A negative impact of climate change was simulated for grazing value (− 11.1% on average), due to the higher suitability to future conditions of Nardus stricta, which has low grazing value compared to other species. Our results highlight that floristic composition should be explicitly considered while assessing climate change impacts on semi-natural pasture productivity and connected ecosystem services.

Carbon Stocks in Vegetation and Soil and Their Relationship with Plant Community Traits in a Mediterranean Non-tidal Salt Marsh

Salt marshes are considered among the ecosystems with the highest capacity for carbon sequestration. However, studies have mainly focused on tidal salt marshes, while knowledge about non-tidal salt marshes, which prevail in the Mediterranean Basin, is currently scarce. Consequently, we aimed to (1) estimate the carbon stocks of the vegetation, litter, and soil of three natural Habitats of Community Interest of a Mediterranean non-tidal salt marsh–a halophilous scrub, a salt meadow, and a glasswort sward–and (2) determine how differences in floristic composition and community structure among habitats over 1 year are related to the amount and distribution of carbon stored in plants and soils. Results show that the halophilous scrub and the salt meadow were constituted by mature plant communities with overall stable carbon stocks in the vegetation, litter, and soil (0–20 cm), which were approximately 4 and 2.5 times larger, respectively, than those found in the glasswort sward (1013 ± 40 g C m−2). However, while the salt meadow and the glasswort sward had more carbon stored in the soil than in the vegetation (approximately 3 and 7.5 times more, respectively), the halophilous scrub had similar amounts in both compartments (2248 ± 388 and 1566 ± 179 g C m−2 in the soil and vegetation, respectively). Sarcocornia fruticosa represented 93.5% of the total plant biomass of the halophilous scrub, which highlights the importance of this species in maintaining carbon stocks in this Mediterranean non-tidal salt marsh.

Characterization of soils on consolidated limestone and its relations to grassland vegetation

Understanding the relations between soil features and plant responses is important for agricultural production and nature conservation. The aim of this study was to investigate the importance of the influence of soils? physical and chemical features on the composition of plant species and richness in grasslands studied on the limestone massif in eastern Serbia (Mt. Rtanj). The data set included 22 phytosociological releves, the same number of corresponding mixed soil samples (0-10 cm depth) and 8 soil profiles. Two vegetation types were distinguished by numerical classification as Saturejion montanae and Festucion valesiacae. The results of detrended correspondence analysis (DCA) indicated that the most important soil parameters affecting species composition in dry grasslands were humus, the content of calcium, soil exchange capacity and base saturation, in addition to total acidity, pH and soil depth. The communities of both vegetation types are developed on Leptosols and Phaeozems. Under similar physical and chemical conditions of the soil, the grassland vegetation exhibits differences in floristic composition.

Main ecological-geographical factors of mire vegetation syntaxa differentiation in Southern Urals

Using gradient analysis and indicator values, it was revealed that the main factors of syntaxa differentiation of mire communities in the South Ural region are acidity and mineral composition of mire-ground waters, variability of habitat moisture and thermo-climatic factors. To a lesser extent, the ordination of mire vegetation syntaxa depends on the general moisture of the habitats and the light factor. The identified nine groups of syntaxa are ordered in the axes of the main ecological factors and are characterized by formations of indicator species. They have clear differences in floristic composition and reflect the specific ecological conditions of mire habitats.

Assessment of quality and chemical composition of continental halophytic grasslands in south-east Europe

Continental halophytic grasslands are known for performing of range of ecosystem services especially remarkable in the regions where they are much distributed – in arid and semi-arid areas. Continental halophytic grasslands of the Central and South-East Europe are not considered as favourable for arable farming, however, traditional animal husbandry plays a crucial role in maintaining biodiversity and preserving these natural habitats. The particular interest of this study is the assessment of the chemical composition of biomass and the quality of insufficiently studied halophytic grassland communities of the central Balkans. In addition, the differences in pastoral value were monitored along the geographical gradient, i.e., between grasslands situated in the Pannonian plain (grasslands of Alliance Puccinellion limosae) and those distributed on the south Serbia (Alliance Festucion pseudovinae). The study was carried out at 18 representative sites, focusing on the saline grasslands of the two distinct regions – on the north and on the south of Serbia. The obtained results show that the halophytic grasslands have satisfying quality characteristics (average values: dry matter - 93.67%, crude protein - 8.66%, cellulose - 30.36%, crude fat - 2.27%) compared with other studied grasslands of saline habitats. There were no significant differences in quality and chemical composition of grasslands of the two regions, despite differences in floristic composition, indicating that salinity is the key determinant for pastoral value of the halophytic vegetation. The certain variations were attributed to the specific floristic composition related to ecological conditions and halophytic community characteristics.

High functional redundancy drives vegetation recovery in Campo rupestre affected by wildfires

• Campo rupestre vegetation tends return to an unburned state after a wildifre • Species composition did not affect functional diversity in Campo rupestre vegetation • Plant cover reestablished in a period of two years after wildfire • Cover reestablishment was driven mainly by cespitose hemicryptophyte High heterogeneity of the floristic component and rapid post-burn vegetation recovery have been reported for Campo rupestre , an azonal peinobiome characterized by a fire-prone vegetation establishing on nutrient-impoverished soils. Although these two key conditions are already known for Campo rupestre , the relationship between them still poorly understood. To test whether floristic composition influences the pattern of post-fire regeneration, we monitored the vegetation recovery of three floristically dissimilar Campo rupestre sites for two consecutive years following wildfires. For each site, we conducted species similarity ordination, rank-abundance distribution, divergence from species to life-form diversity analyses (with an index of diversity divergence) and plant cover in twenty 1 m × 1m plots (10 in burned and 10 in unburned patches). The plots were resampled every four months from December 2015 (one month after wildfire) to November 2017 (24 months after wildfire), totaling seven temporal measurements. We found that the burned grasslands tended to return to a pre-fire state that is similar to control plots that did not burn in 2015. However, each community presented different trajectories in floristic transitions and different degrees of species similarity in relation to an adjacent unburned area. Despite these floristic differences, the three sites reached similar plant cover measures in relation to the non-burned areas. No differences were found for life-form diversity and abundance distribution between communities, suggesting that the differences in floristic composition did not alter the abundance and diversity of functional groups. We conclude that, despite differences in the floristic component, there is high functional redundancy among Campo rupestre communities periodically exposed to wildfires, leading to a similar dynamic of plant recovery during post-fire regeneration.

Comparison of Forest Species- Diversity and Composition Inside and Outside of the Holedná Game Reserve (The City of Brno, Czech Republic)

Abstract The impact of ungulates on the forest vegetation has far-reaching consequences: it decreases species diversity and the production of biomass, causes soil dehydration, erosion and eutrophication the entire forest community. The article addresses the influence of fallow deer and mouflon on the forest vegetation in the Holedná game reserve (western border of the city of Brno, South Moravia, Czech Republic) and compares differences with the forests adjacent to the game reserve. Sixty localities were distributed randomly and phytosociological relevés subsequently recorded there according to the age of the stands inside and outside of the game reserve. The differences in floristic composition were compared for trees, shrubs and herbs, the herb layer species number, the diversity indices and the values of Ellenberg indicators. In the game reserve, a significant difference was found in the coverage of the herb and shrub layer, which was significantly lower than outside the territory. Furthermore, the increased amount of nitrophilous, heliophytes and ruderal herb species inside the game reserve exhibited affiliation to the interior of game reserve. Besides, young trees and woody sapling were less abundant or even missing inside of game reserve. By contrast, the frequency of typical species of oak-hornbeam forests was higher outside game reserve. Due to the higher number of animals and consequent disturbances, nitrophilous plant species dominate in the herb layer of the game reserve, while forest species are more often represented outside it.

Floristic patterns of the neotropical forests, savannas and scrublands with Trithrinax campestris (Arecaceae) in central Argentina

Aims: Trithrinax campestris is one of the palm species with the southernmost distribution in the Neotropics. Despite that the vegetation types in which T. campestris occurs are nowadays heavily threatened by land use and land cover changes, their floristic composition and structure are still to be documented. In order to characterize T. campestris habitats, the aim of this study was to describe the floristic composition of the vegetation types in which this palm occurs and their relationships with different environmental factors. Study area: The survey was conducted in central Argentina in an area comprising the southern extreme of the distribution of T. campestris in the following phytogeographic areas: Espinal, Lowland and Mountain Chaco. Methods: Following the Braun-Blanquet approach we collected 92 floristic relevés recording a total of 601 vascular plant species. Vegetation was classified through the ISOPAM hierarchical analysis. Bioclimatic and elevation data were related to the floristic data through the ISOMAP ordination. Remote-sensed images (Landsat TM, ETM+ and OLI) were used to characterize the fire frequency in the 92 stands. Results: Four vegetation types that differed in floristic composition and in diagnostic species were discriminated: 1.1 Celtis tala/Sida rhombifolia closed forest; 1.2 Aspidosperma quebracho-blanco/Prosopis kuntzei open forest; 2.1 Jarava pseudoichu/Vachellia caven open savanna; and 2.2 Acalypha variabilis/Nassella cordobensis scrubland. The ISOMAP ordination showed that differences in floristic composition were related to elevation, topography and climatic variables.Out of the 92 stands, only 21 showed the occurrence of fires during the period 1999–2018. Conclusions: Our results evidenced that vegetation types (forests, savannas and scrublands) comprising T. campestris developed in a wide range of environmental conditions. This is the first study that focuses on all vegetation types in which T. campestris occurs in central Argentina and it is relevant for conservation and sustainable management of the only native palm species in the flora of this part of the country. Taxonomic reference: Catálogo de las Plantas Vasculares del Cono Sur (Zuloaga et al. 2008) and its online update (http://www.darwin.edu.ar). Abbreviations: ISOMAP = isometric feature mapping; ISOPAM = isometric partitioning around medoids.

Vegetation and flora of marble outcrops and their nearby matrices in mountains of central Argentina. Rock chemistry also matters

We present a comparative study of the flora and vegetation of marble outcrops and their nearby migmatite matrix from mountains in central Argentina. In all, we sampled 50 sites and recorded the cover-abundance of all vascular plants present according to the Braun-Blanquet cover-abundance scale. In addition, rock fragments were collected for chemical analysis (Ca2+, Mg2+, K and Na). Three plant communities were classified using ISOPAM, one occurring in the migmatite matrix and two others associated with calcic (richer in Ca2+) and dolomitic (richer in Mg2+) marble, respectively. The marble outcrops and nearby matrix vegetation differed in plant species and life form composition, as well as in diagnostic species. Rocky outcrops also exhibited differences in floristic composition between dolomitic and calcic marble. The overall number of species in the matrix vegetation was higher than in the outcrop communities, but dolomitic outcrops revealed a higher average species richness per relevé. We found a higher proportion of endemics in the marble vegetation with respect to the surrounding matrix communities, with herbs, grasses and subshrubs dominating in the marble outcrops, while trees and shrubs dominated the matrix vegetation. Taxa of the Southern-Brazilian and Chaquenian chorotypes were the most abundant in the three communities. Our results suggest that the marble outcrops harbor a flora including several highly restricted endemics, which is clearly distinct from that of the surrounding habitats, indicating that outcrop diversity should be taken into account in conservation policies.

The pattern of high plant diversity of Neotropical inselbergs: highlighting endemic, threatened and unique species

ABSTRACT Understanding how multiple drivers shape plant community diversity across environmental gradients is one of the most important issues in plant ecology and biodiversity conservation. We aimed to analyse plant community structure and diversity in four inselbergs in Espirito Santo State, Brazil. We evaluated species diversity, floristic composition and similarity, phytosociological structure, occurrence, and conservation status of rupicolous flora in the inselberg communities. We used field expeditions and plant inventory data from 370 sampling units. We estimated floristic similarity and compared diversity indexes among inselbergs. We observed marked differences in community structure and diversity among inselbergs, where the southern region had the highest number of taxa and higher values of diversity indices. There were also notable differences in floristic composition and phytosociological structure, with a decrease in similarity as geographical distance increased. This finding demonstrated the existence of differences in the patterns of dominance and vegetation cover along the latitudinal gradient, as well as differences in endemic, threatened, and exclusive species, and represents a first step toward establishing criteria for biodiversity conservation for inselbergs in Espirito Santo State.

Differential Use of Forest Patches by the Military Macaw Ara militaris (Psittacidae) in Coastal Tropical Forests of Jalisco, Mexico

Bahia de Banderas in Jalisco, Mexico, contains important vegetation areas for the maintenance and nesting of Military Macaws Ara militaris. However, the forests of the region are not used randomly by Military Macaws across the landscape. This study aimed to evaluate differences in floristic composition, diversity and structure among forest patches used by the macaws for nesting/ roosting or for feeding, and at sites from which the macaws are absent. Field sampling was conducted in 16 plots of 1,000m2 of tropical subdeciduous forest. Statistically significant differences were found in the floristic composition between patches used and avoided by Military Macaws. The used areas were approximately twice as diverse as the avoided areas. The forests at used sites presented a great abundance of species registered as part of their diet, in addition to non-food species such as Oxandra lanceolata, a tree that may be an important component of macaw habitat. In contrast, the dominant species in avoided areas are those associated with disturbed areas and do not provide food for Military Macaws. Our results indicate that Military Macaws select forest fragments in response to disturbance, using forest patches that offer suitable opportunities for nesting and feeding.—Flores-Lopez, E., Montero-Castro, J.C., Monterrubio-Rico, T.C., Ibarra-Manriquez, G., Lopez-Toledo, L. & Carlos Bonilla-Ruz, C. (2020). Differential use of forest patches by the Military Macaw Ara militaris (Psittacidae) in coastal tropical forests of Jalisco, Mexico. Ardeola, 67: 423-432.

Vegetation evolution by ecological succession as a potential bioindicator of landslides relative age in Southwestern Mediterranean region

Landslides have a direct impact in the ecosystems dynamics being considered one of the main vegetation perturbation processes. Our objective is to determine the relation between vegetation cover evolution and time period after landslide disturbance, and therefore to assess the potential use of vegetation evolution within landslide areas as temporal bioindicators of landslide activity, in order to determine landslide relative age. Four rotational slides of known relative age, located in the Grande da Pipa River basin (Arruda dos Vinhos, Portugal) were selected. The methodology includes four main steps: (1) to identify the flora and vegetation differences between the main landslide sectors (scarp, body, foot); (2) to find out if the differences in floristic composition and vegetation structure are reflected in the succession process; (3) to find out if the succession process has produced different seral stages along the longitudinal gradients; (4) to compare the succession process in landslide affected areas with the undisturbed adjacent areas. The data points towards a slow evolution of the vegetation in the period following the disturbance, being necessary long periods for the perturbed area reach vegetation characteristics similar to the ones of the unperturbed areas. The progressive succession is rapid in the foot, slow in the body and extremely slow in the scarp. The presence of orchids in the body may be considered as an age bioindicator of more than 15 years since landslide disturbance. In the case of the older landslide (> 50 years), it corresponds to the evolved stage close to the potential natural vegetation.

Plant diversity in hedgerows and road verges across Europe

Abstract Linear landscape elements such as hedgerows and road verges have the potential to mitigate the adverse effects of habitat fragmentation and climate change on species, for instance, by serving as a refuge habitat or by improving functional connectivity across the landscape. However, so far this hypothesis has not been evaluated at large spatial scales, preventing us from making generalized conclusions about their efficacy and implementation in conservation policies. Here, we assessed plant diversity patterns in 336 vegetation plots distributed along hedgerows and road verges, spanning a macro‐environmental gradient across temperate Europe. We compared herb‐layer species richness and composition in these linear elements with the respective seed‐source (core) habitats, that is, semi‐natural forests and grasslands. Next, we assessed how these differences related to several environmental drivers acting either locally, at the landscape level or along the studied macro‐ecological gradient. Across all regions, about 55% of the plant species were shared between forests and hedgerows, and 52% between grasslands and road verges. Habitat‐specialist richness was 11% lower in the linear habitats than in the core habitats, while generalist richness was 14% higher. The difference in floristic composition between both habitat types was mainly due to species turnover, and not nestedness. Most notably, forest‐specialist richness in hedgerows responded positively to tree cover, tree height and the proportion of forests in the surrounding landscape, while generalist richness was negatively affected by tree height and buffering effect of trees on subcanopy temperatures. Grassland and road verge diversity was mainly influenced by soil properties, with positive effects of basic cation levels on the number of specialists and those of bioavailable soil phosphorus on generalist diversity. Synthesis and applications. We demonstrate that linear landscape elements provide a potential habitat for plant species across Europe, including slow‐colonizing specialists. Additionally, our results stress the possibility for land managers to modify local habitat features (e.g. canopy structure, subcanopy microclimate, soil properties, mowing regime) through management practices to enhance the colonization success of specialists in these linear habitats. These findings underpin the management needed to better conserving the biodiversity of agricultural landscapes across broad geographical scales.

Canopy gaps influence regeneration dynamics in cyclone affected mangrove stands in medium saline zone of the Sundarbans, Bangladesh

Regeneration in the canopy gaps in medium saline zone of the Sundarbans Reserve Forest (SRF), Bangladesh was studied to investigate either significant floristic and structural differences between canopy gaps and adjacent forest with continuous canopy. A total of eighteen plots (30 m × 20 m) with an area of 1.08 ha were sampled from six sites (three sample plots from each sites). Species richness in terms of total number of species (seedling, height < 1.5 m) in the study area was not significantly different between canopy gaps and continuous canopy, but there was still difference in floristic composition. Heritiera fomes and Excoecaria agallocha were the dominant and co-dominant seedling species in both sites but the study demonstrated that Ceriops decanrda, Aegiceras corniculatum and Phoenix paludosa were restricted only in canopy gaps whereas Bruguiera sexangula, Brownlowia tersa, Cerbera manghas and Petunga roxburghii were restricted only in continuous canopy. The study also revealed significant difference of seedling density between gaps (43,454 ha−1) and continuous canopy (28,237 ha−1). The density of H. fomes was significantly higher in canopy gaps (38,952 ha−1) than under continuous canopy (15,298 ha−1). Shannon diversity index (0.41 in gaps and 0.82 in canopy) was significantly reduced (50% of canopy) in the gaps. Our study concluded that canopy gaps enhanced colonization of H. fomes seedlings in the medium saline zone than does of floristic composition and species diversity. The study demonstrate that information on seedling dynamics in the canopy gaps may be important for management and conservation of the SRF.

SEASONAL DIVERSITY OF VEGETATION STRUCTURE OF VEREDAS, MATO GROSSO DO SUL, BRAZIL

Environmental Protection Area Guariroba is an area to protect the headwaters of a creek formed by streams of Veredas, generating the main water supply of municipality of Campo Grande, state of Mato Grosso do Sul, Brazil. Some degraded areas have to be restored; thus, it is important to investigate species composition and variations of the vegetation. Our objective was to evaluate the seasonal variation of the vegetation structure of Veredas within the hydrographic sub-basin. We estimated species cover in five points, each one with 0.5 x 0.5 m plots along 50 m transects on the five stream banks in two seasonal periods. We found 134 species from 95 genera and 49 families. In both seasons, Poaceae, Cyperaceae and Asteraceae were the richest families and the richest genera were Eleocharis (N = 6), Rhynchospora and Utricularia (N = 4). Species richness varied between Veredas, from 31 to 70. We found 41 species exclusive to the rainy season and 38 to the dry season. The analyses identified seven indicator species for the dry season and ten for the rainy season. There are seasonal differences in floristic composition and vegetation cover. Thus, the dynamics of water availability in Veredas, which is related to seasonality, is necessary for the maintenance and functioning of these habitats, which have an important role in local flora, fauna and water availability for the municipality.

Updates on extratropical region climbing plant flora: news regarding a still-neglected diversity

ABSTRACT Most studies concerning climbing plants have focused on lianas, forest ecosystems, and tropical regions. Thus, the majority of existing information is not relevant to all climbing plants (lianas and vines) or all ecoregions of the world (forested and non-forested). We provide an update on floristic and distributional data available for climbing plants in Rio Grande do Sul, Brazil’s southernmost state, which is located within subtropical and temperate zones and includes a variety of forest and non-forest vegetation types. A total of 448 climbing plant species were confirmed and documented by voucher specimens, revealing a diversity similar to that registered for trees in the state (533). The significant contribution of climbing species to the regional flora, the differences in floristic composition and species richness among the state’s eight vegetation types, and the high number of endangered species found in this extratropical region reveal the requirement to expand studies of climbing plants to include environments beyond tropical forests. Furthermore, the importance of herbaceous climbing species in subtropical and temperate floras demonstrates that they should be included in ecological studies of climbing plants, and that future analyses could detect unique or divergent patterns between herbaceous and woody climbers.

Forest fragmentation and impacts of intensive agriculture: Responses from different tree functional groups.

Agricultural landscapes are seen as areas of extreme importance for studying and developing strategies which integrate biodiversity conservation and ecosystem services with food production. The main strategies for intensifying agriculture are based on conventional agricultural practices of frequently using inputs for fertilization and correcting soil pH. Some studies show that these practices generate impacts on nearby forest fragments through soil contamination and increasing nutrient content. The objective of this study was to identify the impacts on the functional groups of sciophilous (late successional/shade-tolerant species) and heliophilous (pioneer/sun-loving) species of a tree community of 14 forest fragments near pasture areas and agricultural areas under conventional practices, raising the hypothesis that higher-fertility forest fragments adjacent to intensive agriculture modify the floristic composition of the tree community. Consequently, this study is based on the following questions: i) Do forest fragments within intensive farming environments present differences in floristic composition of species?; ii) Does the soil fertility influence the tree species composition?; iii) Which variables influence species abundance and richness in the forest fragments with different types of use around their environment? The floristic composition of fragments close to agricultural areas are more similar to each other than the composition of fragments close to pasture areas. Furthermore, the General Linear Model (GLM) results show a clear influence of the intensive farming environment on the richness and abundance of the two functional groups in the forest fragments, directly benefiting the abundance of heliophilous species, which are also benefited by the greater declivity and smaller fragment area, while the abundance of sciophytes is negatively correlated with these last two variables. The increase of calcium content is beneficial for the richness of heliophilous species, while the increase in phosphorus content influences a reduction in the richness of sciophyte species, which also strongly respond to the isolation between fragments. The results indicate a dominance trend of pioneer species in fragments with nutritionally enriched soils, providing evidence that the intense adoption of inputs in cultivated areas causes concrete impacts on the diversity of the tree community.

Woody species diversity as an indicator of the forest recovery after shifting cultivation disturbance in the northern Amazon

The Amazon region harbors the most important tropical forest in the world. However, its biodiversity is seriously threatened due to land-use change. Here, we evaluated changes in tree species diversity and composition after shifting cultivation in the northern Amazon forest, Amazon state, Venezuela, through a chronosequence approach. We selected three sites over a 12 km2 extension of an old-growth forest matrix with secondary forest patches of different stand ages. A total 45 plots (each having 20 × 50 m = 1000 m2) were established. At each site, woody plant diversity and the composition of trees having diameter ≥ 5 cm were assessed in four secondary forests (5, 10, 15, and 20 years old stands after shifting cultivation) and in one old-growth forest (>100 years old), and three plots were established in each forest type. Species richness and dissimilarity pairwise beta-diversity metric were calculated for paired plots among different forest types. We analyzed differences in diversity among the four successional stages and the old-growth forest using individual-based approach. Additionally, multivariate analyses were performed to examine differences among the sampled forest areas in terms of species composition along soil gradient. Species richness showed consistently increasing pattern along the succession to old-growth forest. Species richness in the old-growth forest was up to three times higher than in forests at early successional stages. Richness recovery rate in the 20-years old secondary forest two decades after the abandonment of shifting cultivation was on average equal to 70% of the species richness in the old-growth forest. In contrast, the recovery of species composition reached an average 25% in relation to the old-growth forest during the same period. Our results show that the effect of stand age and environmental drivers (i.e., soil properties) determine species diversity along succession. The environmental heterogeneity between successional stages can be analyzed by the differences in floristic composition and beta diversity observed among the analyzed plots. For that reason, we presume that beta diversity is the major determinant of species richness in secondary forests. The proposed approach contributes to the sustainable management of forest communities because it allows estimating the woody species diversity recovering after shifting cultivation disturbance across successional stages.