Interference and management of parthenium: The world's most important invasive weed

Parthenium (Parthenium hysterophorus L.) is one of the most aggressive herbaceous weeds of the Asteraceae family. It is widely distributed, almost across the world and has become the most important invasive weed. Comprehensive information on interference and control of this devastating species is required to facilitate better management decisions. A broad review on the interference and management of this weed is presented here. Inspite of its non-tropical origin, parthenium grows quite successfully under a wide range of environmental conditions. It is spreading rapidly in Australia, Western Africa, Asia, and Caribbean countries, and has become a serious weed of pastures, wastelands, roadsides, railwaysides, water courses, and agricultural crops. The infestations of parthenium have been reported to reduce grain and forage yields by 40–90%. The spread of parthenium has been attributed to its allelopathic activity, strong competitiveness for soil moisture and nutrients, and its capability to exploit natural biodiversity. Allelochemicals released from parthenium has been reported to decrease germination and growth of agronomic crops, vegetables, trees, and many other weed species. Growth promoting effects of parthenium extracts at low concentrations have also been reported in certain crops. Many pre- and post-emergence herbicides have been evaluated for the control of parthenium in cropped and non-cropped areas. The most effective herbicides are clomazone, metribuzin, atrazine, glyphosate, metsulfuron methyl, butachlor, bentazone, dicamba, and metsulfuron methyl. Extracts, residues, and essential oils of many allelopathic herbs (Cassia, Amaranthus, and Xanthium species), grasses (Imperata and Desmostachya species), and trees (Eucalyptus, Azadirachta, Mangifera species, etc.) have demonstrated inhibitory activities on seed germination and seedling growth of parthenium. Metabolites of several fungi, e.g., Fusarium oxysporun and Fusarium monilifonne, exhibit bioherbicidal activity against seeds and seedlings of this weed. Intercropping, displacement by competitive plant species like Cassia species, bisset bluegrass, florgen blugress, buffelgrass, along with the use of biological control agents like Mexican beetle, seed-feeding and stem-boring weevils, stem-galling and leaf-mining moth, and sap-feeding plant hopper, have been reported as possible strategies for the management of parthenium. An appropriate integration of these approaches could help minimize spread of parthenium and provide sustainable weed management with reduced environmental concerns.

Development of Sample Pretreatment and Liquid Chromatographic Techniques for Antioxidative Compounds

In this study, novel methodologies for the determination of antioxidative compounds in herbs and beverages were developed. Antioxidants are compounds that can reduce, delay or inhibit oxidative events. They are a part of the human defense system and are obtained through the diet. Antioxidants are naturally present in several types of foods, e.g. in fruits, beverages, vegetables and herbs. Antioxidants can also be added to foods during manufacturing to suppress lipid oxidation and formation of free radicals under conditions of cooking or storage and to reduce the concentration of free radicals in vivo after food ingestion. There is growing interest in natural antioxidants, and effective compounds have already been identified from antioxidant classes such as carotenoids, essential oils, flavonoids and phenolic acids. The wide variety of sample matrices and analytes presents quite a challenge for the development of analytical techniques. Growing demands have been placed on sample pretreatment. In this study, three novel extraction techniques, namely supercritical fluid extraction (SFE), pressurised hot water extraction (PHWE) and dynamic sonication-assisted extraction (DSAE) were studied. SFE was used for the extraction of lycopene from tomato skins and PHWE was used in the extraction of phenolic compounds from sage. DSAE was applied to the extraction of phenolic acids from Lamiaceae herbs. In the development of extraction methodologies, the main parameters of the extraction were studied and the recoveries were compared to those achieved by conventional extraction techniques. In addition, the stability of lycopene was also followed under different storage conditions. For the separation of the antioxidative compounds in the extracts, liquid chromatographic methods (LC) were utilised. Two novel LC techniques, namely ultra performance liquid chromatography (UPLC) and comprehensive two-dimensional liquid chromatography (LCxLC) were studied and compared with conventional high performance liquid chromatography (HPLC) for the separation of antioxidants in beverages and Lamiaceae herbs. In LCxLC, the selection of LC mode, column dimensions and flow rates were studied and optimised to obtain efficient separation of the target compounds. In addition, the separation powers of HPLC, UPLC, HPLCxHPLC and HPLCxUPLC were compared. To exploit the benefits of an integrated system, in which sample preparation and final separation are performed in a closed unit, dynamic sonication-assisted extraction was coupled on-line to a liquid chromatograph via a solid-phase trap. The increased sensitivity was utilised in the extraction of phenolic acids from Lamiaceae herbs. The results were compared to those of achieved by the LCxLC system.

Effects of recreational use and fragmentation on the understorey vegetation and soil microbial communities of urban forests in southern Finland

The impacts of fragmentation and recreational use on the hemiboreal urban forest understorey vegetation and the microbial community of the humus layer (the phospholipid fatty acid (PLFA) pattern, microbial biomass and microbial activity, measured as basal respiration) were examined in the greater Helsinki area, southern Finland. Trampling tolerance of 1) herb-rich OMT, 2) mesic MT, and 3) sub-xeric VT forests (in decreasing order of fertility) was studied by comparing relative understorey vegetation cover (urban/untrampled reference ratio) of the three forest types. The trampling tolerance of forest vegetation increased with the productivity of the site (sub-xeric < mesic < herb-rich). Wear of understorey vegetation correlated positively with the number of residents (i.e., recreational pressure) around the forest patch. An increase of 15000 residents within a radius of 1 km around a forest patch was associated with ca. 30% decrease in the relative understorey vegetation cover. The cover of dwarf shrub Vaccinium myrtillus in particular decreased with increasing levels of wear. The cover of mosses in urban forests was less than half of that in untrampled reference areas. Cover of tree saplings, mainly Sorbus aucuparia, and some resilient herbs was higher than in the reference areas. In small urban forest fragments, broad-leaved trees, grasses and herbs were more abundant and mosses were scarcer than in larger urban forest areas. Thus, due to trampling and edge effects, resilient herb and grass species are replacing sensitive dwarf shrubs, mosses and lichens in urban forests. Differences in the soil microbial community structure were found between paths and untrampled areas and the effects of paths extended more than one meter from the paths. Paths supported approximately 25-30% higher microbial biomass with a transition zone of at least 1 m from the path edge. However, microbial activity per unit of biomass was lower on paths than in untrampled areas. Furthermore, microbial biomass and activity were 30-45% lower at the first 20 m into the forest fragments, due to low moisture content of humus near the edge. The decreased microbial activity detected at forest edges and paths implies decreased litter decomposition rates, and thus, a change in nutrient cycling. Changes in the decomposition and nutrient supply may in turn affect the diversity and function of plant communities in urban forests. Keywords: boreal forest vegetation, edge effects, phospholipid fatty acids, trampling, urban woodlands, wear

The effects of habitat edges and trampling intensity on vegetation in urban forests

Although changes in urban forest vegetation have been documented in previous Finnish studies, the reasons for these changes have not been studied explicitly. Especially, the consequences of forest fragmentation, i.e. the fact that forest edges receive more solar radiation, wind and air-borne nutrients than interiors have been ignored. In order to limit the change in urban forest vegetation we need to know why it occurs. Therefore, the effects of edges and recreational use of urban forests on vegetation were investigated together in this thesis to reveal the relative strengths of these effects and to provide recommendations for forest management. Data were collected in the greater Helsinki area (in the cities of Helsinki, Vantaa and Espoo, and in the municipalities of Sipoo and Tuusula) and in the Lahti region (in the city of Lahti and in the municipality of Hollola) by means of systematic and randomized vegetation and soil sampling and tree measurements. Sample plots were placed from the forest edges to the interiors to investigate the effects of forest edges, and on paths of different levels of wear and off these paths to investigate the effects of trampling. The natural vegetation of mesic and sub-xeric forest site types studied was sensitive both to the effects of the edge and to trampling. The abundances of dwarf shrubs and bryophytes decreased, while light- and nitrogen-demanding herbs and grasses - and especially Sorbus aucuparia – were favoured at the edges and next to the paths. Results indicated that typical forest site types at the edges are changing toward more nitrophilic vegetation communities. Covers of the most abundant forest species decreased considerably – even tens of percentages – from interiors to the edges indicating strong edge effects. These effects penetrated at least up to 50 m from the forest edges into the interiors, especially at south to west facing open edges. The effects of trampling were pronounced on paths and even low levels of trampling decreased the abundances of certain species considerably. The effects of trampling extended up to 8 m from path edges. Results showed that the fragmentation of urban forest remnants into small and narrow patches should be avoided in order to maintain natural forest understorey vegetation in the urban setting. Thus, urban forest fragments left within urban development should be at least 3 ha in size, and as circular as possible. Where the preservation of representative original forest interior vegetation is a management aim, closed edges with conifers can act as an effective barrier against solar radiation, wind and urban load, thereby restricting the effects of the edge. Tree volume at the edge should be at least 225-250 m3 ha-1 and the proportion of conifers (especially spruce) 80% or more of the tree species composition. Closed, spruce-dominated edges may also prevent the excessive growth of S. aucuparia saplings at urban forest edges. In addition, closed edges may guide people’s movements to the maintained paths, thus preventing the spontaneous creation of dense path networks. In urban areas the effects of edges and trampling on biodiversity may be considerable, and are important to consider when the aim of management is to prevent the development of homogeneous herb-grass dominated vegetation communities, as was observed at the investigated edges.

Using a botanic garden collection to test a bioclimatic vegetation scheme

Vegetation maps and bioclimatic zone classifications communicate the vegetation of an area and are used to explain how the environment regulates the occurrence of plants on large scales. Many practises and methods for dividing the world’s vegetation into smaller entities have been presented. Climatic parameters, floristic characteristics, or edaphic features have been relied upon as decisive factors, and plant species have been used as indicators for vegetation types or zones. Systems depicting vegetation patterns that mainly reflect climatic variation are termed ‘bioclimatic’ vegetation maps. Based on these it has been judged logical to deduce that plants moved between corresponding bioclimatic areas should thrive in the target location, whereas plants moved from a different zone should languish. This principle is routinely applied in forestry and horticulture but actual tests of the validity of bioclimatic maps in this sense seem scanty. In this study I tested the Finnish bioclimatic vegetation zone system (BZS). Relying on the plant collection of Helsinki University Botanic Garden’s Kumpula collection, which according to the BZS is situated at the northern limit of the hemiboreal zone, I aimed to test how the plants’ survival depends on their provenance. My expectation was that plants from the hemiboreal or southern boreal zones should do best in Kumpula, whereas plants from more southern and more northern zones should show progressively lower survival probabilities. I estimated probability of survival using collection database information of plant accessions of known wild origin grown in Kumpula since the mid 1990s, and logistic regression models. The total number of accessions I included in the analyses was 494. Because of problems with some accessions I chose to separately analyse a subset of the complete data, which included 379 accessions. I also analysed different growth forms separately in order to identify differences in probability of survival due to different life strategies. In most analyses accessions of temperate and hemiarctic origin showed lower survival probability than those originating from any of the boreal subzones, which among them exhibited rather evenly high probabilities. Exceptionally mild and wet winters during the study period may have killed off hemiarctic plants. Some winters may have been too harsh for temperate accessions. Trees behaved differently: they showed an almost steadily increasing survival probability from temperate to northern boreal origins. Various factors that could not be controlled for may have affected the results, some of which were difficult to interpret. This was the case in particular with herbs, for which the reliability of the analysis suffered because of difficulties in managing their curatorial data. In all, the results gave some support to the BZS, and especially its hierarchical zonation. However, I question the validity of the formulation of the hypothesis I tested since it may not be entirely justified by the BZS, which was designed for intercontinental comparison of vegetation zones, but not specifically for transcontinental provenance trials. I conclude that botanic gardens should pay due attention to information management and curational practices to ensure the widest possible applicability of their plant collections.

Photosynthesis of ground vegetation in boreal Scots pine forests

Research on carbon uptake in boreal forests has mainly focused on mature trees, even though ground vegetation species are effective assimilators and can substantially contribute to the CO2 uptake of forests. Here, I examine the photosynthesis of the most common species of ground vegetation in a series of differently aged Scots pine stands, and at two clear-cut sites with substantial differences in fertility. In general, the biomass of evergreen species was highest at poor sites and below canopies, whereas grasses and herbs predominated at fertile sites and open areas. Unlike mosses, the measured vascular species showed clear annual cycles in their photosynthetic activity, which increased earlier and decreased later in evergreen vascular species than in deciduous species. However, intraspecific variation and self-shading create differences in the overall level of photosynthesis. Light, temperature history, soil moisture and recent possible frosts could explain the changes in photosynthesis of low shrubs and partially also some changes in deciduous species. Light and the occurrence of rain events explained most of the variation in the photosynthesis of mosses. The photosynthetic production of ground vegetation was first upscaled, using species-specific and mass-based photosynthetic activities and average biomass of the site, and then integrated over the growing season, using changes in environmental factors. Leaf mass-based photosynthesis was highest in deciduous species, resulting in notably higher photosynthetic production at fertile sites than at poor clear-cut sites. The photosynthetic production decreased with stand age, because flora changed towards evergreen species, and light levels diminished below the canopy. In addition, the leaf mass-based photosynthetic activity of some low shrubs declined with the age of the surrounding trees. Different measuring methods led to different momentary rate of photosynthesis. Therefore, the choice of measuring method needs special attention.

Sharavathi River Basin Flora Information System(SRFIS)

The INFORMATION SYSTEM with user friendly GUI’s (Graphical user Interface) is developed to maintain the flora data and generate reports for Sharavathi River Basin. The database consists of the information related to trees, herbs, shrubs and climbers. The data is based on the primary field survey and the information available in flora of Shimoga, Karnataka and Hassan flora. User friendly query options based on dichotomous keys are provided to help user to retrieve the data while data entry options aid in updating and editing the database at family, genus and species levels.

Ethnobotany of the Monpa ethnic group at Arunachal Pradesh, India

Background: The present paper documents the uses of plants in traditional herbal medicine for human and veterinary ailments, and those used for dietary supplements, religious purpose, local beverage, and plants used to poison fish and wild animals. Traditional botanical medicine is the primary mode of healthcare for most of the rural population in Arunachal Pradesh. Materials and methods: Field research was conducted between April 2006 and March 2009 with randomly selected 124 key informants using semi-structured questionnaire. The data obtained was analyzed through informant consensus factor (F(IC)) to determine the homogeneity of informant's knowledge on medicinal plants. Results: We documented 50 plants species belonging to 29 families used for treating 22 human and 4 veterinary ailments. Of the medicinal plants reported, the most common growth form was herbs (40%) followed by shrubs, trees, and climbers. Leaves were most frequently used plant parts. The consensus analysis revealed that the dermatological ailments have the highest F(IC) (0.56) and the gastro-intestinal diseases have F(IC) (0.43). F(IC) values indicated that there was high agreement in the use of plants in dermatological and gastro-intestinal ailments category among the users. Gymnocladus assamicus is a critically rare and endangered species used as disinfectant for cleaning wounds and parasites like leeches and lice on livestocks. Two plant species (Illicium griffithii and Rubia cordifolia) are commonly used for traditional dyeing of clothes and food items. Some of the edible plants recorded in this study were known for their treatment against high blood pressure (Clerodendron colebrookianum), diabetes mellitus (Momordica charantia), and intestinal parasitic worms like round and tape worms (Lindera neesiana, Solanum etiopicum, and Solanum indicum). The Monpas of Arunachal Pradesh have traditionally been using Daphne papyracea for preparing hand-made paper for painting and writing religious scripts in Buddhist monasteries. Three plant species (Derris scandens, Aesculus assamica, and Polygonum hydropiper) were frequently used to poison fish during the month of June-July every year and the underground tuber of Aconitum ferrox is widely used in arrow poisoning to kill ferocious animals like bear, wild pigs, gaur and deer. The most frequently cited plant species; Buddleja asiatica and Hedyotis scandens were used as common growth supplements during the preparation of fermentation starter cultures. Conclusion: The traditional pharmacopoeia of the Monpa ethnic group incorporates a myriad of diverse botanical flora. Traditional knowledge of the remedies is passed down through oral traditions without any written document. This traditional knowledge is however, currently threatened mainly due to acculturation and deforestation due to continuing traditional shifting cultivation. This study reveals that the rural populations in Arunachal Pradesh have a rich knowledge of forest-based natural resources and consumption of wild edible plants is still an integral part of their socio-cultural life. Findings of this documentation study can be used as an ethnopharmacological basis for selecting plants for future phytochemical and pharmaceutical studies.

Keystone food resources for honey bees in South Indian west coast during monsoon

The low level, denuded, laterite landscape of coastal Uttara Kannada has a rich diversity of monsoon herbs, including threatened and newly discovered ones. Our study reveals that honey bees congregate on the ephemeral herb community of Utricularias, Eriocaulons and Impatiens during their gregarious monsoon flowering period. Apis dorsata had highest visitations on Utricularias, Impatiens and Flacourtia indica, whereas Trigona preferred Eriocaulons. Laterite herb flora merits conservation efforts as a keystone food resource for the insect community, especially for honey bees.

Aprendendo o uso das ervas: a trajetória de terapeutas populares

A utilização de ervas e plantas para finalidades terapêuticas é bastante antiga e registrada em várias sociedades. Esta pesquisa procura investigar como se dá o processo de construção e reprodução do conhecimento em medicina popular (particularmente o cuidado com ervas e plantas medicinais) através da história de vida de terapeutas populares pessoas que se tornaram referências em suas comunidades por adquirir, praticar e transmitir esse conhecimento. Tem como objetivos conhecer e compreender o processo de construção do conhecimento sobre plantas medicinais por terapeutas populares do município do Rio de Janeiro; compreender as formas de reprodução deste conhecimento; entender o contexto de relações destes terapeutas com o saber científico. Utilizou-se como opção metodológica a história oral com ênfase na história de vida. Foram entrevistados sete terapeutas populares de diferentes bairros do município. Observou-se que o conhecimento em relação às ervas medicinais não está restrito a um pequeno grupo e limitado a uma forma de transmissão oral. O conhecimento tem se reproduzido, mas também tem se modificado, mesclando-se com outras formas de conhecimento e entremeado por diversas fontes de informação que vão desde a transmissão oral até informações disponíveis na mídia. A principal forma de reprodução do conhecimento parece ser a perpetuação do negócio, que evoca o discurso do tradicional, a natureza das ervas e suas propriedades benéficas e se sustenta por uma rede de informação que se utiliza dos diversos meios de comunicação e uma rede de produção e comércio que garante o sustento econômico dos terapeutas populares. A transformação das práticas de utilização de ervas medicinais em patrimônio cultural ou negócio de família além de garantir a perpetuação do conhecimento, garante um espaço diferente dentro das práticas de cuidado em saúde. As relações dos terapeutas com a medicina oficial não são relações de tensões, embora haja criticas, mas de interposição de sistemas terapêuticos.

A utilização da fitoterapia e de plantas medicinais em unidades básicas de saúde nos municípios de Cascavel e Foz do Iguaçu Paraná: a visão dos profissionais de saúde

A fitoterapia e o uso de plantas medicinais fazem parte da prática da medicina popular, que diminuiu frente ao processo de industrialização nas décadas de 1940 e 1950, aumentando a busca, pela população, por terapias menos agressivas destinadas ao atendimento primário à saúde. Essa complementa o tratamento usualmente empregado para a população de menor renda. O objetivo deste trabalho foi analisar o conhecimento dos gestores e profissionais de saúde que atuam na atenção primária, sobre fitoterapia e uso de plantas medicinais, nos municípios de Cascavel e Foz do Iguaçu - Paraná. Para tanto, no período de fevereiro a julho de 2009, foi realizado estudo exploratório, descritivo, qualitativo, empregando como instrumentos de pesquisa entrevistas semiestruturadas e um questionário estruturado, auto aplicado, com perguntas fechadas, a fim de contemplar os seguintes aspectos: perfil dos profissionais; aceitabilidade quanto à implantação da fitoterapia na atenção básica; confiança nos tratamentos com fitoterápicos; capacitação e formação profissional relacionadas à fitoterapia, entre outros itens. Um dos gestores considerou recente o programa de fitoterapia. Indicadores de satisfação da população quanto ao uso dos fitoterápicos ou plantas medicinais ainda não existem. O gestor do município de Cascavel relatou interesse na implantação do programa. Os demais profissionais entrevistados, de maneira geral, relataram não haver recebido formação sobre o tema durante a graduação, nem mesmo dentro das UBS onde trabalham. Entre os profissionais entrevistados seis (60%) relataram o acesso às informações sobre fitoterapia através do conhecimento popular, uma (10%) formação na UBS, dois (20%) através de periódicos, quatro (40%) através de meio de comunicação, sendo que quatro citaram mais que uma das opções. Em Foz do Iguaçu, nas UBS onde a terapêutica está implantada, os profissionais relataram não terem sido consultados antes de sua implantação, e a avaliação das plantas utilizadas pelos pacientes atendidos ocorre somente através de avaliação objetiva e subjetiva do tratamento Para implantação da fitoterapia nas UBS desses dois municípios, é necessário capacitar os profissionais quanto ao tema, desde o cultivo até a prescrição, melhorando o uso racional desses medicamentos.

Nas tramas de Itamatatiua: representações sociais, práticas de saúde e as trocas comunicativas dos filhos de Santa Teresa

No presente estudo utiliza-se a Teoria das Representações Sociais, iniciada por Serge Moscovici, ao publicar a obra La Psychanalyse son image et son public em 1961. Para o autor, as representações sociais são originadas a partir das definições de linguagem e comunicação configurando-se em uma conexão de idéias, metáforas e imagens mentais em constante dinâmica, sendo sustentadas pela comunicação. Essa perspectiva teórica se propõe a entender como os indivíduos e grupos sociais compreendem o mundo, sua realidade e as circunstâncias nas quais se comunicam, compartilham idéias, ações, crenças, ideologias e interagem entre si e com os outros. Este estudo tem como objetivo compreender como os indivíduos constroem e reconstroem os conceitos e as práticas de saúde, as relações estabelecidas entre saúde e doença e como caracterizam as práticas tradicionais de saúde existentes na comunidade negra de Itamatatiua - Maranhão. No que se refere à metodologia utilizou-se os principíos da etnometodologia aliados à etnografia, com o intuito de perceber os modos de dizer e fazer saúde na comunidade. Mediante pesquisa de campo verificou-se que os itamatatiuenses vivem um momento de transição social, política e econômica que vem se repercutindo nas práticas de saúde. A manutenção e utilização de praticas tradicionais de saúde, que envolvem chás, ervas de giraus, emplasto, garrafadas, benzimentos e curandeirismo continua a ser observada, coexistindo com as práticas institucionais do Programa de Saúde da Família. As construções simbólicas em torno da saúde estabelecem relações complexas em uma rede que envolve o momento de transmissão oral; a promessa de saúde e a fé em Santa Teresa; questões territóriais que se traduzem em título de cidadania quilombola e melhoria de qualidade de vida; cultura da cerâmica como base econômica; transição alimentar com a entrada no mercado de consumo dos alimentos industrializados; modo de vida, na maior parte das vezes, harmonioso; relações conflituosas entre os múltiplos saberes em interação, que envolve o conhecimento reificado institucionalizado e o conhecimento popular. Concluí-se que através da oralidade as experiências práticas de saúde das gerações antepassadas se consolidaram e hoje se colocam em paralelo as práticas institucionalizadas governamentais e privadas, constituindo um conjunto de representações características dessa comunidade.

Hekate, de deusa ctônica dos atenienses do período clássico à deusa da feitiçaria no imaginário social do Ocidente

Nosso eixo temático se desenvolve a partir do questionamento do epíteto de Deusa da Feitiçaria atribuído tardiamente à deidade grega Hekate. A partir do período Clássico em Atenas iniciaram-se críticas às práticas mágico-religiosas cujo objetivo era fazer mal ao inimigo; realizadas por indivíduos (mágoi - magos) os quais também sabiam utilizá-las para a cura, como o uso das phármaka (ervas). O desenvolvimento da Escola de Medicina Hipocrática, no período Clássico, e seus tratados médicos, se configuram como uma das críticas direcionadas aos mágoi e das divindades que evocavam em suas práticas mágicas. Um tratado em especial, Da Doença Sagrada, combate a divinização da epilepsia e as práticas curativas desta enfermidade através da persuasão dos deuses. Platão também teceu críticas aos que ofereciam seus serviços mágicos de porta em porta por uma pequena quantia. Acreditamos que a partir dessas críticas se desenvolveu no imaginário social ateniense a relação entre a deusa grega Hekate e a magia de fazer mal ao inimigo cuja permanência é observada nos dias atuais. Nosso arcabouço teórico constitui-se dos conceitos desenvolvidos pelo filósofo polonês Bronislaw Baczko no verbete imaginação social na Enciclopedia Einaudi.

Assembleia de aves consumidoras de frutos de sub-bosque em diferentes altitudes em uma área de Mata Atlântica no estado do Rio de Janeiro

Neste estudo, investigamos a distribuição altitudinal da composição, riqueza, abundância das espécies de aves consumidoras de frutos em cinco altitudes e avaliamosa influência da estrutura da vegetação nas diversidades de aves. O estudo foi realizado na Reserva Ecológica de Guapiaçu (REGUA) contígua ao Parque Estadual dos Três Picos (PEPT), no município de Cachoeiras de Macacu, RJ. Coletamos os dados das aves em 24 excursões a campo, incluindo seis bimensais (jul./2010 a maio/2011) e 18 mensais (jul./2011 a dez./2012). Para amostragem das aves, utilizamos o método de captura-marcação-recaptura com redes de neblina, expostas durante sete h/dia em cinco altitudesao longo de uma variação altitudinal de 1000 m. O esforço amostral foi de 8400 h-rede. Para amostragem da estrutura da vegetação, sorteamos três parcelas de 100 m2 adjacentes às linhas das redes em cada altitude, nas quais foram analisadas as densidades de diferentes hábitos de vida. Das árvores, arvoretas e arbustos coletamos as medidas de altura total e diâmetro da altura (no caso dos arbustos, o diâmetro foi coletado a 50 cm do solo). Capturamos 448 indivíduos correspondentes a 35 espécies de aves, distribuídas em 16 famílias. Destas, 26% são endêmicas de Mata Atlântica, incluindo quatro espécies categorizadas com algum grau de vulnerabilidade. Dezesseis espécies foram classificadas como frugívoras enquanto 19 como insetívoras-frugívoras. Leptopogon amaurocephalus, Mionectes rufiventris, Lanio melanops, Chiroxiphia caudata foram capturadas nas cinco altitudes, sendo as últimas duas espécies as mais abundantes. Registramos maior riqueza e abundância de aves nas altitudes de 370 e 770 m. A composição de aves diferiu entre as altitudes, sendo 170 e 1000 m as mais dissimilares. As espécies de aves insetívoras-frugívoras predominaram nos sub-bosques das cinco altitudes. Registramos deslocamento altitudinal de cinco espécies de aves, sendo o maior deslocamento realizado por um indivíduo de Attilarufus, capturado a 770 m e, recapturado a 370 m. Encontramos maior densidade de plantas no sub-bosque nas altitudes 170, 370 e 1000 m. Bambus foram registrados apenas a 1000 m, enquanto que as ervas foram limitadas às altitudes de 170 e 370 m. A estrutura da vegetação apresentou baixa similaridade entre as altitudes, principalmente devido a diferentes densidades das formas de vida e altura das plantas. Três altitudes, 170, 370 e 1000 m, apresentaram alta densidade de indivíduos no sub-bosque, sendo que esta última evidenciou uma estrutura da vegetação relativamente mais simples devido ao alto número de árvores de baixa altura, ao maior número de arvoretas e à presença de bambus. A diversidade de aves foi sensível à estrutura da vegetação, em especial à altura das árvores que apresentou um decréscimo da altura com o aumento da altitude. Esta relação entre a diversidade de aves e a estruturada da vegetação destaca a importância da preservação da estrutura da vegetação para a manutenção da diversidade de aves consumidoras de frutos da REGUA e do PETP

异质性环境中两种匍匐茎草本植物的克隆可塑性

　　克隆植物常常生长在资源异质性分布的环境中，克隆植物特有的生活史特征使其对环境和资源变化产生的反应规范（Reaction norm）具有特殊的表现和适应意义。本文以匍匐茎草本植物蛇莓(Duchesnea indica)和活血丹(Glechoma longituba)为材料，研究克隆植物在不同异质性环境中的反应规范，即可塑性（plasticity）和克隆分株间相互作用（即克隆整合（clonal integration））对表型的影响及其适应意义。 蛇莓和活血丹是具有不同分枝类型的两种匍匐茎草本植物。对于匍匐茎草本植物而言，生境中光资源分布在时间和空间上的变化极为丰富。本文主要研究在不同环境中，这两种克隆植物克隆分株间的相互作用是如何通过影响其形态特征，从而影响其光资源获取策略。 实验涉及了4种光照条件，分为5个部分，分别在大棚和野外进行。 1．同质光环境中蛇莓和活血丹克隆片段的可塑性 在大棚中，将整个克隆片段（clonal fragment）都放置在光照强度分别为自然光照PPFD（Photosynthetic Photon Flux Density）的100％、50％和10％三种不同的同质光环境中，目标是通过比较不同光照强度同质环境中不同基因型的形态特征，揭示匍匐茎草本克隆植物的反应规范及遗传差异。实验结果发现，当光照强度从100% PPFD 降到 50% PPFD时，活血丹增加对地上部分生物量投资，增加部分多投入到匍匐茎上，用于支持匍匐茎实现觅食行为，叶片和叶柄的变化不大。同样条件下，蛇莓的生物量投资却向根部转移，地上部分叶片和叶柄形态上的变化比匍匐茎的形态变化显著，出现增强对光资源吸收能力的变化。当光照强度从50%降到 10%时，活血丹继续增加对地上部分的生物量投资，但由于光照强度弱，几乎不足以维持新的匍匐茎的发生，所有增加的生物量部分都投入到叶片和叶柄的变化上。这种条件下，蛇莓的生物量投资依然向根部转移，叶片和叶柄为增加对光资源吸收能力而发生了相应变化，匍匐茎的新增数减少，形态变化也不大。实验证明，可能由于匍匐茎的发生方式不同，活血丹的匍匐茎节间长度，叶片和叶柄的关联程度比蛇莓相应性状的关联程度强。不同基因型的蛇莓和活血丹对光照梯度的反应有显著差异。 2．异质光环境中蛇莓克隆片段的可塑性 针对克隆植物分株间在相当长的时间里形体相连，而环境异质性可能存在于分株大小的空间尺度，设置异质环境，将蛇莓的不同相连分株放置在不同的光资源斑块中，研究其整合作用在适应异质性环境过程中的作用及其对表型的影响。首先设置同一种资源（光资源）的梯度差异斑块。 在光斑块中，整合作用发生与否、作用方式与资源梯度、分株自身所处斑块的资源条件和分株的年龄结构有关。在不同的条件下，整合作用可能造成对表型的不同影响，从而可能加剧或削弱分株对本地资源的反应（局部反应，local response）。整合作用对分株局部反应的影响强度和方向，在不同基因型间存在明显差异。这些基因型间的差异暗示，整合作用可能也是具有遗传基础的一种独立性状。 3．光块斑和养分斑块共存环境中活血丹克隆片段的可塑性 设置光和养分的资源互补性斑块。将相连分株种植在不同斑块中。当生长在高光低养斑块中的分株与其互补斑块（低光高养斑块）的分株相连时，其适合度相关性状的值增加，根冠比是可塑的，通过相应的形态变化，高光照斑块中的分株捕获光资源的能力增强，但两种斑块中植株的吸收养分的能力却没有大的变化。收益－损耗分析显示整合作用有益于异质环境中的植株，低光高养斑块中植株的生物量获益。实验结果证明了异质环境中相连分株间存在光合产物和养分传递。在这种环境种，分株形态的变化对本地斑块发生趋富反应，形态的改变有助于对本地丰富资源的吸收。这种反应有利于克隆片段对资源的吸收。 4．野外环境中蛇莓克隆片段的可塑性 基于大棚实验资料，对野外林下蛇莓种群进行监测。首先对单株在林下复杂的光环境中的表现进行了跟踪，结果发现，随着分株数目的增加，适合度相关性状值有所提高，而处于不同位置的相连分株在形态上的差异不显著。大棚实验中发现的显著形态变化在具有显著差异的自然环境条件下没有发生，这可能暗示着在资源条件变化频率较高的环境中整合作用的作用方式。分株不是对某一时刻资源条件进行形态特化，而是通过对所扩展的总体区域的总的环境条件调整表型。这样，从克隆片段的水平上看，资源的吸收可能达到较高水平。在密度增大，植株间互相荫蔽使得光照减弱的情况下，匍匐茎的变化没有表现出觅食行为，叶片和叶柄出现增大增长等增强吸收光能力的相应表型变化，证明叶片叶柄是克服光照不足的主要器官。这些结果与大棚实验结果一致。蛇莓基株对于相连分株内部可能具有密度调节功能，从而通过减弱叶片增大的趋势，增长匍匐茎，分散新生分株，使密度保持在一定程度，不对种群的发展造成阻碍作用。非相连分株间随着密度的增大，相互间的作用方式类似于非克隆植物：出现叶片增大，叶柄增长的现象，同时密度制约了适合度相关性状如分株数目等的增加。 5．野外环境中蛇莓种群格局动态 最后，在进化的单位，种群水平上对蛇莓种群在自然界的动态进行了调查。Spearman相关分析，没有发现光资源和测量指标在量上的相关。在自然界中整合作用使大量分散分布、相互连接的分株相互作用，以促进基株对资源的获取。Moran’s I指数分析显示，随时间的推进，各个指标在相关尺度上有所增加。这暗示了整合作用的存在，分株间联系的加强。大棚实验中观察到的关于各个器官的作用的结论在自然界中得到进一步的验证。蛇莓匍匐茎在遮荫环境中不是作为觅食器官。为了争取对更多光资源的吸收，蛇莓在叶片数和叶形态上发生改变。对分株数、叶片数、匍匐茎数目的分布格局的调查显示出没有一定的规律性，而且处于不断的变化中。这一结果可能暗示种群发展过程中处理异质性分布资源的对策的变化。 此外，本文还揭示了可塑性和整合作用在基因型间的差异，针对所发现的现象，从作用的遗传机制上对可塑性及其适应意义进行了讨论。结合分子生物学和地统计学等学科的研究成果，对进一步的实验提出了方法和路线。