Woody Flora Research Articles

Threatened woody flora as an ecological indicator of large herbivore introductions

Rewilding and translocations of large herbivores for conservation purposes have increased in recent times, with numerous introductions inside and outside their native range. This study aims to analyze the use of threatened plant taxa as a possible ecological indicator of large herbivore introductions. We examined the effects of a threatened large ungulate, the Barbary sheep (Ammotragus lervia), on both endangered and vulnerable woody taxa after its introduction in 1970. Contrary to our hypothesis, the herbivore impact on threatened woody species was higher than that found on widespread woody plants. The results reveal that 35.7% of the threatened species showed the highest possible level of herbivore damage in contrast to 6.5% for the widespread species. Threatened species were preferred over common plants, probably due to their greater palatability. Overall plant cover, including neighboring species, was also an important factor determining browsing damage and, thus, habitats with low ground cover should be particularly considered in conservation plans. Herbivore damage on common taxa should be taken with caution since they could mask unsustainable herbivore densities for threatened woody taxa or protected habitats. The use of threatened woody taxa through the studied ecological indicators (herbivore damage, plant preferences, habitat use and regeneration success) represented a useful tool to assess the sustainability of large herbivores introductions and to establish a priority conservation ranking for threatened plant species. These findings highlight the deleterious effects of overabundant ungulate populations regardless its origin (exotic or native) and the need of monitoring threatened woody taxa to better estimate the suitability and sustainability of large herbivore introductions.

Woody species of the Miombo woodlands and geoxylic grasslands of the Cusseque area, south-central Angola

The species composition of the vegetation in most regions of Angola has been poorly studied and most studies date back to the pre-independence era. In this study, we provide a detailed account of the woody flora of the Miombo woodlands and geoxylic grasslands of the Cusseque study site of “The Future Okavango” (TFO) project, situated on the Angolan Central Plateau. The checklist is based on a vegetation survey using vegetation plots of 1,000 m² and also includes records from botanical collections made elsewhere at the study site. In total, we documented 154 woody species belonging to 99 genera of 37 plant families in 100 km². The study represents the first comprehensive account of the woody vegetation of the area including all habitats and growth forms.

Angiosperm species of “Cerrado” sensu stricto in Terra Ronca State Park, Brazil: floristics, phytogeography and conservation

We conducted a floristic survey of “Cerrado” sensu stricto on Quartzipsamment soils in the northeastern state of Goias, Brazil, in Terra Ronca State Park (PETeR). In addition, we analysed phytogeographical aspects to investigate the floristic relationships between “Cerrado” and the Amazon, Atlantic Forest and “Caatinga” biomes. Furthermore, we assessed the shrub–tree flora similarity with other sites having the same type of physiognomy and soil class. We collected species along three 5 km × 60 m (90 ha) transects and recorded 278 species. Erythroxylum loefgrenii Diogo, Eugenia blanchetiana O.Berg and Martianthus stachydifolius (Epling) Harley & J.F.B.Pastore were listed as new records for the “Cerrado” (Brazilian savanna), and thirteen species were newly recorded for the state of Goias. Approximately, 28% of the species are endemic to the “Cerrado”, and 72% are shared with other Brazilian biomes. The shrub–tree layer of the “Cerrado” shares more species with the “Caatinga”, which shows the transitional aspects and affinities of the local flora with this biome. The high similarity between the woody flora of PETeR and “Cerrado” sensu stricto on Quartzipsamment soil sites in Bahia and northern Minas Gerais state associated with the occurrence of floristic elements that considered typical of the north–northeast portion of the “Cerrado” phytogeographical province reinforces the inclusion of the northeast region of Goias in this floristic province. The protected area in the Vao do Parana region represents only 3.3% of the total area of the region and 6% of the remaining natural vegetation in the area. Considering that the studied region holds an important flora and at the same time presents strong anthropogenic pressure from the occupation of agribusiness, it would be extremely important to prioritize conservation strategies to maintain the remaining natural vegetation in the northeastern portion of the “Cerrado”.

<p class="Body" align="left">A critical checklist of the woody flora of Tuscany (Italy)

A comprehensive checklist of the Tuscan woody flora providing sub-regional details is presented. This checklist comprises 412 taxa, of which 264 are native and 148 are non-native. Nine taxa new for the region were found, and eleven taxa were excluded from the regional flora. The native taxa belong to 109 genera and 53 families. Rosaceae is the family richest in taxa, with Rosa being the genus with the highest number of species. On the provincial level, the province of Grosseto is the province with the highest number of native taxa, followed by the provinces of Lucca and Florence. The lowest number of taxa was documented in the provinces of Pistoia and Prato. With regard to the non-native woody flora, the highest number of non-native taxa can be found in the province of Livorno, whereas the lowest number occurs in the provinces of Arezzo and Siena. At regional level, 9% of non-native taxa are invasive, 45% naturalized and 46% casual. Asia and North America are the most common native ranges of those taxa. After an extensive herbarium study, the taxonomy and distribution of Acer opalus, Cornus sanguinea, Juniperus deltoides, Oreoherzogia alpina, Pyrus communis, Quercus crenata, Salix elaeagnos, and Sorbus aria are discussed in more detail.

The most commonly available woody plant species are the most useful for human populations: a meta-analysis.

An increasing number of studies have aimed to clarify the factors leading human groups to prioritize the use of some woody plant species compared to others. Some of these studies have tested the apparency hypothesis in aiming to understand this phenomenon. According to the apparency hypothesis, the most commonly available local plant species on a forest path are the most useful to that local human population. However, the sparse and diverse nature of the results from studies investigating the factors that influence human exploitation of plant resources motivated us to perform a meta-analysis on the apparency hypothesis. We searched in the main databases (Scopus, ScienceDirect, Google Scholar, and Scielo) for studies that correlated the environmental availability of woody species (estimated through vegetation parameters) with the degree of importance of such species to the local human population (estimated by means of the use value index). Overall, this meta-analysis supported the apparency hypothesis, although we also found high levels of heterogeneity in these studies. When the distinct uses of woody flora were considered separately, we found that local species availability is important for fuelwood (firewood and charcoal) and construction (houses, fences, etc.) purposes but does not explain medicinal and technological (object manufacture) plant use. We found no important differences in correlationvalues between the degree of species importance for people and the different vegetation parameters, although correlations are slightly higher for the dominance and importance value index. Our findings suggest that the exploitation of woody flora is influenced by local availability.

New insights on the origin of the woody flora of the Chihuahuan Desert: The case of Lindleya.

We reconstructed aspects of the evolutionary history of Lindleya, a shrubby element in the rose family, as a model for identifying the ancestral area of the biota of the Chihuahuan Desert and for understanding the effect that pre-Pleistocene or Pleistocene climate fluctuations had on the evolution of the plants of this desert. We conducted phylogenetic, biogeographic, and phylogeographic analyses based on one nuclear DNA and two plastid markers sequenced for 20 populations comprising 153 accessions and representing the species' entire distribution range. We carried out ecological niche modeling to forecast Lindleya's potential distribution under Current, Last Interglacial, and Last Glacial Maximum conditions. The ancestral area of Lindleya populations was probably in the central and southern parts of the Chihuahuan Desert. Levels of genetic and haplotype variation were the highest in the northernmost and southernmost areas and low levels of genetic variation in the central part. Extended Bayesian skyline plots including all populations identified a slight demographic expansion ∼1 Ma. The predicted potential distribution during the Last Glacial Maximum was very restricted. We suggest that pre-Pleistocene changes had an influence on the divergence of Lindleya populations. We also suggest that the ancestral area for Lindleya was the Chihuahuan Desert and that the uplift of the Trans-Mexican Volcanic Belt isolated the Tehuacán Valley populations. Genetic and demographic analyses as well as and ecological niche modeling indicate that populations of Lindleya experienced genetic bottlenecks and that they have expanded since the Last Glacial Maximum.

Метаболічний склад листків дерев залежно від умов росту

The transformation of the urban environment led to changes in the life of woody flora. These changes are not always noticeable visually, and their appearance often suggests nothing of irreversible physiological (biochemical) change body. Formation of important substances of plant organism depends on the functional processes (synthesis of protein, carbohydrates, nitrogen compounds) in which the operation is normal. Most expeditious structural and functional changes can be seen in the assimilation organs (leaves). Knowing the essence of adaptive processes at the level of metabolism tree growing in a transformed urban environment, we can understand the morphological changes and as a result find the optimal measures to improve the green spaces and maintain their livelihoods in "difficult" environment that is relevant for today urban green economy. The aim is to study the content of basic biochemical parameters in the dry mass of leaves studied groups of trees and installation possible dependence of quantitative and qualitative values of these parameters depending on growth conditions, and identifying features of life of native and exotic trees in the transformed conditions of the urban environment and their adaptive response to environmental factors. To study the biochemical parameters of life of woody plants city green zone allocated to 3 groups of tree species of oak (Quercus robur L.) and bahryanyk Japanese (Cercidiphyllum japonicum Siebold et Zucc.). Oak stands as a typical representative of the green zone. City belongs to the native flora. Cultivation bahryanyk in our area began in the last century because of our climatic zone it belongs to introduced species. Subject studied biochemical metabolic dry mass of leaves at the height of summer activities, including study of water-soluble carbohydrates, starch, protein and lipids. To evaluate the physiological response of plants to growth conditions studied makrometabolic sheet structure on the main important indicators of water soluble carbohydrates, fiber, lipids. Studies have shown that in the urban environment course of biochemical processes is worse than a close to natural environmental conditions. Environment of urban pervert the course of carbohydrate, lipid and other exchanges. A significant drop in performance microclimate, soil and air pollution sensitivity of plants to changing environmental conditions. Research of macro metabolic composition of bahryanyk and oak in the green area of Lviv allowed to find out that changes functional structures of the leaf are displayed in organic and mineral components of its dry weight. The conditions of the urban environment affect carbohydrate metabolism and "adjusting" the content of the main structural components. Transformed environment of the city causes the plant organism to accumulate a reserve stock of components - starch and lipids. Also found that rates of sugar and starch in the dry mass of leaves depends on the growth conditions and specific features. It was found difference between the metabolism of native oak and introduced bahryanyk. Last actively accumulate reserve compounds, especially in polluted outdoor environments. In turn, oak showed better adaptability to local conditions. Confirmed that the research of assimilating organs clearly shows the main changes in the plant organism on physiological and biochemical level, caused by habitat transformation and pollutants in the environment. Leaves can be considered as the primary basis of morpho-physiological adaptation of plants.

Savanna woody encroachment is widespread across three continents.

Tropical savannas are a globally extensive biome prone to rapid vegetation change in response to changing environmental conditions. Via a meta-analysis, we quantified savanna woody vegetation change spanning the last century. We found a global trend of woody encroachment that was established prior the 1980s. However, there is critical regional variation in the magnitude of encroachment. Woody cover is increasing most rapidly in the remaining uncleared savannas of South America, most likely due to fire suppression and land fragmentation. In contrast, Australia has experienced low rates of encroachment. When accounting for land use, African savannas have a mean rate annual woody cover increase two and a half times that of Australian savannas. In Africa, encroachment occurs across multiple land uses and is accelerating over time. In Africa and Australia, rising atmospheric CO2 , changing land management and rainfall are likely causes. We argue that the functional traits of each woody flora, specifically the N-fixing ability and architecture of woody plants, are critical to predicting encroachment over the next century and that African savannas are at high risk of widespread vegetation change.

Using woody genera for phytogeographic regionalization at a medium scale: a case study of Italy

We present a phytogeographic regionalization based on native woody flora, identifying the most useful taxonomic level, geographic variables, and orographic pattern, selecting Italy as a case study. We generated seven distance matrices among the 20 administrative regions, and using Pearson’s correlation coefficients and PCA, we verified whether distances between regions were invariant across the different sampling strategies. Once this invariance was established, we focused on genera representation. We defined two orographic indices and performed Kruskal–Wish multidimensional scaling and K-means clustering to assess Italy’s phytogeographic regionalization. A major north–south and a minor east–west gradient described the relationships between regions. Floristic diversity was strongly correlated with the region’s orography, with hills being the most important orographic feature that increased plant diversity; the effect of the orographic patterns was independent from the geographic clines observed. Despite the coarse scale, our phytogeographic regionalization comprising six clusters (variables = 133 woody genera) was consistent with previous ones based on the endemic flora (variables = 1371 units) or on bioclimatic approaches. In particular, the phytogeographic uniqueness of Northern and peninsular Italy, and of Sardinia Island, was confirmed. The next step will be to test our method at a finer scale.

Woody flora of natural forest gaps in a bamboo-dominated forest remnant in southwestern Amazonia

Abstract: Forest gaps, created by the falling of one or more trees, have been seen as a key factor for the maintenance of local plant diversity in tropical forests. In this study, our goal was to determine the floristic composition of woody plants colonizing natural gaps and in the understory of an open, bamboo-dominated (Guadua weberbaueri Pilg.) forest in southwestern Amazonia, Acre, Brazil. We sampled and identified woody plants (≥1 m tall and DBH≤10 cm) in 20 forest gaps and nine adjacent understories. In total, 1656 plants were identified in 159 species, 116 genera and 45 families. A list of species was created, containing habitat, habit, functional group, threat status (Brazilian Flora Red List) and abundance data for each species.

Phylogenetic impoverishment of plant communities following chronic human disturbances in the Brazilian Caatinga

Chronic disturbances, such as selective logging, firewood extraction and extensive grazing, may lead to the taxonomic and phylogenetic impoverishment of remaining old-growth forest communities worldwide; however, the empirical evidence on this topic is limited. We tested this hypothesis in the Caatinga vegetation--a seasonally dry tropical forest restricted to northeast Brazil. We sampled 11,653 individuals (adults, saplings, and seedlings) from 51 species in 29 plots distributed along a gradient of chronic disturbance. The gradient was assessed using a chronic disturbance index (CDI) based on five recognized indicators of chronic disturbances: proximity to urban center, houses and roads and the density of both people and livestock. We used linear models to test if mean effective number of lineages, mean phylogenetic distance and phylogenetic dispersion decreased with CDI and if such relationships differed among ontogenetic stages. As expected, the mean effective number of lineages and the mean phylogenetic distance were negatively related to CDI, and such diversity losses occurred irrespective of ontogeny. Yet the increase in phylogenetic clustering in more disturbed plots was only evident in seedlings and saplings, mostly because clades with more descendent taxa than expected by chance (e.g., Euphorbiaceae) thrived in more disturbed plots. This novel study indicates that chronic human disturbances are promoting the phylogenetic impoverishment of the irreplaceable woody flora of the Brazilian Caatinga forest. The highest impoverishment was observed in seedlings and saplings, indicating that if current chronic disturbances remain, they will result in increasingly poorer phylogenetically forests. This loss of evolutionary history will potentially limit the capacity of this ecosystem to respond to human disturbances (i.e., lower ecological resilience) and particularly their ability to adapt to rapid climatic changes in the region.

Changes in Structure and Diversity of Woody Plants in a Secondary Mixed Pine-Oak Forest in the Sierra Madre del Sur of Mexico

The biotic province of the Sierra Madre del Sur presents a mosaic of woodlands at different successional stages due to frequent modifications in land use. In this study, we analyzed changes in woody flora across three successional stages of pine-oak forest: early, intermediate, and mature. Vegetation composition and diversity were characterized in 10 plots (each 0.28 ha). The mature stage had the highest values for species richness, abundance, and diversity. Pioneer plants were dominant in the early-successional site and may promote the establishment of late-successional species. The vegetation structure was more complex in the mature stage, where members of the Quercus genus were co-dominant with Pinus species. Pine tree richness was highest in the early-successional stage, and its abundance increased at the intermediate-successional site. These results suggest that Pinus species can grow in perturbed and sunny environments but also require favorable edaphic and microclimatic conditions, such as those found in intermediate woodlands. Results of this fieldwork support the initial floristic composition succession model, which suggests that species present at early stages will also occur in subsequent stages. Ecological succession may be considered to be a natural restoration process, and thus, conservation strategies should focus on maintaining distinct successional communities in addition to mature forests in order to preserve a high number of species.

VALUE OF AN URBAN FRAGMENT FOR THE CONSERVATION OF CERRADO IN THE FEDERAL DISTRICT OF BRAZIL

The Brazilian Federal District (FD) has 25% of the total woody flora of the Cerrado biodiversity hotspot, but has lost most of its vegetation cover and 30% of its plant species are considered extinct. Here we evaluate the conservation potential of an Cerrado in FD that is strategically located between key protected areas. The study was conducted in two sites within the Gama e Cabeca de Veado Environmental Protection Area: the urban fragment and a control site. We found a high floristic and structural similarity between the sites, suggesting that in the past they formed a continuous landscape. The was floristically diverse, with indices that are considered high and typical for Cerrado. The studied fragment, therefore, can help reduce the ongoing deterioration of FD's biodiversity, due to its vegetation representativeness and strategic location, potentially acting as a stepping stone between key protected areas. The study gives support to ongoing efforts to transform the studied area into a protected area.

Assessment of Floristic Diversity on the Bank of Nigeen Lake, Kashmir Valley

The present study was carried out along the bank of Nigeen Lake, in Srinagar city of Kashmir valley. The aim of the study was to present the scenario of phytosociology with respect to the importance value index (IVI), species diversity, species dominance, and to document the herbal and woody flora. Moreover, medicinal uses of some plants and their status of availability in the area were also studied. The present study was undertaken from June to December, 2014. Overall, 27 herb species belonging to 15 families were recorded along the bank of Nigeen Lake; which includes 13 species of medicinal plants (about 50% of the total flora). While as, in case of woody vegetation, 7 species belonging to 6 families have been recorded and only one species of shrub i.e., Rubus niveus from Rosaceae family has been observed. Outcome of the study revealed that flora of a Nigeen Lake provides information about the total number of plant species present along the riparian zone of Nigeen Lake, their identification, description, distribution and economic utility. Further, the present study can be used as a source of basic data for the management and larger-scale conservation planning of riparian zones of Nigeen Lake.

Patterns of tree composition in the southern cone of South America and its relevance to the biogeographic regionalization

The biogeographic history of southern South America has led to a markedly distinct flora within the frame of the Neotropics, which is also particularly heterogeneous in terms of its eco-geographic distribution. This environmental complexity is at the base of the many and controversial classification systems that have been proposed for the vegetation of the so-called Cono Sur region (Paraguay, Chile, Argentina, Uruguay and parts of Brazil and Bolivia). In this study, we aimed to assess the floristic consistency of the main vegetation types that inhabit the region. Our dataset consisted of 116,130 occurrence records of 3662 species of shrubs and trees in 781 sampling sites spread over six countries and eight phytogeographic domains: Atlantic Forest, Pampa, Gran Chaco, Patagonia, Southern Andean, Mediterranean Chile, Temperate Pacific, and Pacific Islands. We performed a cluster analysis and nonmetric multidimensional scaling ordination analysis of this dataset followed by multi-response permutation procedures and permutational multivariate analysis of variance and taxonomic distinction index and indicator species. The greater differentiation took place among the phytogeographic domains and leaf flush regimes (evergreen, deciduous, and semideciduous) though there was also a remarkable latitudinal gradient. Our analyses showed that the pre-defined vegetation types were consistent in terms of woody flora composition and have a considerable number of indicators, many of which endemic. In terms of conservation prioritization, Atlantic Rain Forest therefore has importance because of its high species richness while temperate and mediterranean forests west of the Andes should not be ignored given that they show much higher endemism than would be expected given their species richness.

A novel phylogenetic regionalization of phytogeographical zones of southern Africa reveals their hidden evolutionary affinities

AbstractAimAlthough existing bioregional classification schemes often consider the compositional affinities within regional biotas, they do not typically incorporate phylogenetic information explicitly. Because phylogeny captures information on the evolutionary history of taxa, it provides a powerful tool for delineating biogeographical boundaries and for establishing relationships among them. Here, we present the first vegetation delineation of the woody flora of southern Africa based upon evolutionary relationships.LocationSouthern Africa.MethodsWe used a published time‐calibrated phylogenetic tree for 1400 woody plant species along with their geographical distributions and a metric of phylogenetic beta diversity to generate a phylogenetic delineation of the woody vegetation of southern Africa. We then explored environmental correlates of phylogenetic turnover between them, and the evolutionary distinctiveness of the taxa within them.ResultsWe identified 15 phylogenetically distinct biogeographical units, here referred to as phyloregions. The largest phyloregion broadly overlaps with Savanna vegetation, while the phyloregion overlapping with the south‐western portion of the Fynbos biome is the most evolutionarily distinct. Potential evapotranspiration and mean annual temperature differ significantly among phyloregions and correlate with patterns of phylogenetic beta diversity between them. Our phylogeny‐based delimitation of southern Africa's woody vegetation broadly matches currently recognized phytogeographical classifications, but also highlights parts of the Namib Karoo and Greater Limpopo Transfrontier Park as distinct, but previously under‐recognized biogeographical units.Main conclusionsOur analysis provides new insights into the structure and phylogenetic relationships among the woody flora of southern Africa. We show that evolutionary affinities differentiate phyloregions closely resembling existing vegetation classifications, yet also identify ‘cryptic’ phyloregions that are as evolutionarily distinct as some of the recognized African vegetation types.

Black Wattle (Acacia mearnsii De Wild.) in Rwanda’s Forestry: Implications for Nature Conservation

Invasive species pose a serious threat to the conservation of biodiversity. Forestry is the most important driver of the introduction and spread of invasive woody plant species after horticulture. Nearly 450 invasive tree species have been recorded worldwide, amounting to more than half the world’s total invasive woody flora. Australian-native Acacia mearnsii De Wild. is one of world’s top invasive alien tree species related to forestry. The negative impacts of alien species spilling over into conservation areas because of forestry are increasingly being recognized, and we examined the context and timing of this Australian species’ arrival in Rwanda. The role of A. mearnsii in Rwanda’s colonial and postcolonial forestry and the species’ threat to biodiversity conservation are also investigated. The results suggest that A. mearnsii (a) was introduced into Rwanda between 1903 and 1918, with the earliest formal record dating back to 1941; (b) was a major forestry tree species until the late 1960s when its use in forestry declined significantly; and (c) demonstrates a comparatively higher occurrence and potential of regeneration within the understory of Eucalyptus plantations within the Congo-Nile ridge buttress; Bufundu and Bushiru; and Budaha, Ndiza, and Buberuka agro-bioclimatic zones. More recently, A. mearnsii has invaded national parks and forest reserves above 1,600 m of altitude. The most significant case was recorded at Nyungwe National Park (NNP), East Africa’s largest montane rainforest. A study of biomass and spatial patterns of this species in specific ecosystems, such as NNP, is strongly recommended in order to uphold effective conservation practices.

Has Ever Brahmaea Ledereri Rogenhofer, 1873 Inhabited the Colchis Refugium

The biogeographical background. There are two refugial centers in Transcaucasia: Colchis (along the Black Sea coast) and Hyrcan (Hyrcania) (along the Caspian Sea shore). Elements from Europe and Asia and their biogeographical subdivisions compose flora and fauna, which combined with the diverse geomorphology (Laurasian, Gondvanian), the presence of the impressive mountain ridge of the Great Caucasus, its insularity during 100 million years (from Cretaceous time), have resulted in a high taxonomic (species, genera) richness and endemism. The both refugiais characterized by a rather uniform thermical indexes, considerably the former one. The both shelters consist of an extraordinary abundance and diversity of thermophilic woody flora (trees, shrubs and vines) belonging to Arcto-Tertiary Geoflora. Except species typical for nemoral biota, there are extremely rare species of tropical-subtropical origin, which became extinct in South Caucasus during the Tertiary (at the close of the Pliocene) climate deterioration. In response to cooling climate and physiographic changes, some rare genera became restricted to both refugia of Transcaucasia. Most of them are now confined chiefly within the Hyrcanianrefugium (species of Albizia, Gleditsia, Panthera, Hystrix). Among the invertebrate fauna of Tertiary origin should be considerably mentioned species of remarkable nocturnal Brahmin moth – Brahmaea Walker. The interdisciplinary study of the orthodox view regarding the vicariant event between two species of moths as thoughthey are indigenous of Colchis (B. ledereri) and Talysh (B. christophi) does not actually exist. The reason circumstances to express such opinion remain important due for a variety of reasons which are given below.

Heterogeneity of the woody flora of swamp forests in southeastern and southern Brazil

Swamp forests are associated with hydromorphic soils and are naturally fragmented in their distribution. Several local phytosociological surveys on the woody flora of these forests have been conducted in southeastern and southern Brazil. We present here a comprehensive floristic list based on these surveys, including 77 families, 211 genera and 518 native species. The richest families were Myrtaceae (78 species), Fabaceae (47) and Lauraceae (38). The richest genera were Eugenia (24), Myrcia (24), Miconia (21) and Ocotea (20). The woody flora of these swamp forests has great heterogeneity, with most species occurring in one or few sites. Their flora is formed by a few flooding specialist or tolerant species, common in many sites, and many other species that come from the surrounding vegetation. Considering the high degree of deforestation in southeastern and southern Brazil, including swamp forests, the floristic patterns presented here can be useful for the future efforts of conservation, management and restoration of these forests.

A Broad Transition from Cloud Forest to Páramo Characterizes an Undisturbed Treeline in Parque Nacional Llanganates, Ecuador

This study aimed at investigating the vegetation pattern associated with the transition from upper northern Andean cloud forest to páramo grassland in a relatively unmodified area in Ecuador’s Eastern Cordillera. Single 20 × 10 m plots were randomly placed in representative sites along an altitudinal gradient from continuously wet Andean montane cloud forest at 3400–3700 m to páramo grassland at 3900–4000 m. Also sampled was a disjunct stand of the stem-rosette Espeletia pycnophylla var. llanganatensis, some 200 km south of the limit of the otherwise continuous distribution of this genus. Several physical and chemical soil factors, including temperature at -30 cm, were determined. Visual estimates of cover in four life-form classes (trees, shrubs, herbs, ground cover) at each site revealed similarities related to their relative proximity along an elevation gradient. Stands with a tree cover were more species-rich than those without, due largely to the differential distribution of the woody flora. No abrupt discontinuity occurred in the mix of species along this gradient. Soil temperature and altitude were the most important factors of those measured to explain the variability in plant community structure and composition. There was no clear zonation evident along the altitudinal gradient, with vegetation structure and floristics displaying continuous variation. No clear upper forest limit was differentiated. The isolated presence of Espeletia in the area is discussed, but the theory about its origin remains speculative.