The terrestrial orchid Thelymitra matthewsii Cheeseman, uncommon in New Zealand, was studied to increase knowledge of the species life cycle, morphology and ecology. Results will enhance future conservation management for the species. New information related to the morphology of T. matthewsii was obtained. The species was found to emerge in one of four discrete life stages of distinctive morphology and height range that remained constant for the season, not developing into a more advanced life stage. The leaf of the three pre adult life stages designated a hook, a spiral, and a non flowering stage, did not inflate at the base, but rose smoothly from the tuber. Apparent morphological differences in the column between descriptions of the Australian taxon and the small New Zealand sample examined suggested further study was needed. Comprehensive monthly monitoring was carried out at five study sites in three locations in the Te Paki area of the Far North, from 2002 to 2004. No patterns emerged in plant life stage succession, flowering, and presence or absence at labels reinforcing the concept that variability was a common component of the population census. Seasonal and partial absence was a major component of the populations. An average of 32.8% of plants, over five study sites, were present throughout three seasons, while 66.9% were recorded as absent (not visible) at monitoring. New plants appearing in 2003 and 2004 showed a high percentage of subsequent absence (mean 85.7%). To determine population stability, recruitment and absence were compared. Plant absence exceeded recruitment by 7% (mean plant absence 30.5%; mean recruitment 23.4%). Plants continued to appear during the monitoring period, and labeled plants increased two-fold over commencement numbers. Adults recorded as 28% of labeled plants over three seasons, were out numbered by pre-flowering stages. Only 5% of population numbers exhibited succession from a smaller to a flowering plant. Life stage modeling indicated a life stage was more likely to be followed by the same stage than an expected successive stage. Thelymitra matthewsii was found to be present in four substrates in the Far North. The survey of vegetation found the indigenous species Kunzea ericoides and the exotic Hakea gibbosa dominant for both height, and cover. Litter and bare ground dominated ground cover. Differences in vegetation and ground cover, of sites supporting T. matthewsii and comparison sites that did not, were minor and suggested that another factor, for example a suitable fungal partner, influenced the species presence or absence. The results of the study indicated the present threat classification of Thelymitra matthewsii is inadequate in the light of the species relatively circumscribed, widely separated habitats, the small number of reproducing individuals and vulnerability to habitat modification.

Submitted by Marco Antônio de Ramos Chagas (mchagas@ufv.br) on 2016-10-17T17:48:28Z No. of bitstreams: 1 texto completo.pdf: 7428003 bytes, checksum: 9b45ac43f60ec458c377f6800ae1c29a (MD5) / Made available in DSpace on 2016-10-17T17:48:28Z (GMT). No. of bitstreams: 1 texto completo.pdf: 7428003 bytes, checksum: 9b45ac43f60ec458c377f6800ae1c29a (MD5) Previous issue date: 2005-02-04 / Possuindo cerca de 19500 espécies, Orchidaceae é uma das maiores famílias dentre as Fanerógamas, com aproximadamente 2400 espécies brasileiras. Foram estudadas Cleistes gracilis, Epidendrum secundum, Epidendrum xanthinum, Habenaria hydrophila, Habenaria janeirensis, Habenaria macronectar, Oncidium barbaceniae, Oncidium blancheti, Pleurothallis montana, Pleurothallis teres, Prescottia montana, Zygopetalum mackaii e Zygopetalum brackypetalum com objetivo de caracterizar anatomicamente as raízes e as folhas, identificando caracteres anatômicos úteis na interpretação das estratégias adaptativas e na solução de problemas taxonômicos. Folhas expandidas e raízes foram coletadas em um campo de altitude na Serra do Brigadeiro/MG. As amostras foram incluídas em metacrilato ou cortadas em micrótomo de mesa e os cortes corados com azul de toluidina pH 4,0 ou azul de astra/safranina, respectivamente. As lâminas foram montadas em resina sintética ou em gelatina glicerinada. Epidermes foliares foram dissociadas e procedeu-se a maceração de folhas e raízes. Os testes histoquímicos aplicados foram: sudan IV e sudan black B para lipídios; floroglucina para lignina; lugol para amido. Amostras radiculares e foliares foram avaliadas ao microscópio eletrônico de varredura. As espécies perenes E. secundum, E. xanthinum, O. barbaceniae, O. blancheti, P. prolifera, P. teres, Z. mackaii e Z. brackypetalum apresentaram vários caracteres xeromórficos adaptados à sobrevivência em ambiente com forte insolação, seca, altitude elevada, nebulosidade, baixas temperaturas, vento forte e solo com deficiência nutricional. Presença de pseudobulbos, folhas coriáceas ou coriáceas suculentas, hipoestomáticas, estômatos protegidos por projeções e com poros obliterados, células epidérmicas com pontoações na parede, cutícula espessa, hipoderme, grupos de fibras no mesofilo, idioblastos, parênquima aqüífero, feixes vasculares envolvidos por fibras, velame pluriestratificado permitem concluir que as espécies são xeromorfas e que tais características se relacionam como estratégias adaptativas, para um efetivo controle de fluxo hídrico dentro do limbo foliar. E. secundum, E. xanthinum, P. prolifera e P. teres, mesmo sendo terrícolas e rupículas apresentaram várias características anatômicas equivalentes às descritas para epifíticas. C. gracilis, H. hydrophila, H. janeirensis, H. macronectar e P. montana completam seu ciclo antes do período seco, possuindo redução periódica das partes aéreas. Nestas espécies, as folhas são delgadas e caracteres xeromórficos não são acentuados, por estarem menos sujeitas à estresse, pois, quando a parte vegetativa está totalmente presente, concomitantemente, ocorre disponibilidade hídrica e umidade atmosférica. Os caracteres morfológicos vegetativos externos e os anatômicos não permitiram a distinção das duas espécies do gênero Epidendrum sendo fundamental, por esse motivo, utilizar caracteres reprodutivos a fim de distinguí-las no campo. Entretanto, no presente trabalho, foram identificadas características anatômicas da lâmina foliar que contribuíram para a identificação das demais espécies estudadas, mesmo quando em forma vegetativa. / Orchidaceae, that owns around 19500 species, is one of the largest families of Phanerogams, with approximately 2400 Brazilian species. Cleistes gracilis, Epidendrum secundum, Epidendrum xanthinum, Habenaria hydrophila, Habenaria janeirensis, Habenaria macronectar, Oncidium Pleurothallis teres, barbaceniae, Prescottia Oncidium montana, blancheti, Zygopetalum Pleurothallis mackaii and montana, Zygopetalum brackypetalum were studied in order to characterize their roots and leaves, identifying anatomical characteristics helpful to the interpretation of adaptation strategies and to the solution of taxonomic problems. The samples collected at Serra do Brigadeiro/MG were included in methacrylate and cut in rotary microtome. The sections were stained with toluidine blue, pH 4,0, and mounted in synthetic resin. Freehand sections were stained with astra blue/safranina and the slides mounted in glycerinated jelly. Foliar epidermises were dissociated, roots and leaves were macerated. The histochemical tests applied were: sudan IV and sudan black B for lipid; phloroglucin for lignin; lugol for starch. Xeromorphic features adapted to the survival in environment under high irradiance, drought, high altitude, cloudiness, low temperatures, strong wind and soil with nutritional deficiency appeared in the species E. secundum, E. xanthinum, O. barbaceniae, O. blancheti, P. prolifera, P. teres, Z. mackaii and Z. brackypetalum. Presence of pseudobulbs, coriaceous and hypostomatic leaves, stomata protected by projections and with obliterated pores, epidermic cells with bordered pits and thick cuticle, hypoderm, fibres groups in mesophyll, idioblasts, aquiferous parenchyma, vascular bundles involved by fibers and pluristratified velamen allow to conclude that the species are xerophytes and that these characteristics are adaptative strategies to an effective control of water flux in the leaf blade. Even being terricolous and rupicolous, E. secundum, E. xanthinum, P. prolifera and P. teres showed anatomical characteristics equivalent to that described to epiphytic species. C. gracilis, H. hydrophila, H. janeirensis, H. macronectar and P. montana complete their cycle before drought time, with periodic reduction of aerial organs. In these species, leaves are thin and xeromorphic characteristics are not observed; when the vegetative part is totally present, there is water availability and atmospheric humidity, and the species are not submitted to stress. The morphological and anatomical features of vegetative organs are not sufficient to recognize the two species of Epidendrum being necessary to use reproductive features to distinguish them in the field. However, to the others species, the anatomical foliar characteristics were useful for the identification of the species even in vegetative stage. / Dissertação importada do Alexandria

No description available.

Made available in DSpace on 2014-06-12T15:02:42Z (GMT). No. of bitstreams: 2 arquivo2076_1.pdf: 3360789 bytes, checksum: 2d5b1a9180b6f5c6cdd46d9026fd0c3e (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2010 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Cattleya granulosa Lindl. é uma orquídea endêmica e ameaçada de extinção restrita a fragmentos de Floresta Atlântica do Nordeste do Brasil. A biologia floral e os sistemas reprodutivos de C. granulosa no Parque das Dunas e Barreira do Inferno no Rio Grande do Norte foram investigados, e ainda, foram realizadas coletas de machos de abelhas Euglossini atraídos por iscas odores para verificar a ocorrência de políneas aderidas ao corpo. As flores apresentam cores que variam entre os tons esverdeados, amarelados e castanhos avermelhados, osmóforos que produzem fragrância fortemente adocicada e guias de néctar no labelo que absorvem luz ultravioleta. Mimetizam um modelo geral de flor tipicamente melitófila, porém produz pouco néctar floral e pode estar atuando com um mecanismo de engodo. As visitas que resultam em polinização são muito raras e a frutificação é baixa (9,19%) para as duas áreas estudadas e isso pode ter gerado a ausência dos polinizadores efetivos nas observações focais. Existe diferença significativa na formação natural de frutos entre as duas áreas, sendo o Parque das Dunas o local de menor frutificação. Cattleya granulosa é autocompatível, porém dependente de polinizador para reprodução, haja vista que nesta espécie não ocorreu reprodução vegetativa nas duas áreas. Os resultados do estudo são discutidos acerca dos atributos florais relacionados à síndrome de polinização melitófila, dos visitantes das flores e os prováveis polinizadores, do sistema reprodutivo e a importância do vetor de pólen, assim como, as causas da fragmentação da Floresta Atlântica e medidas mitigadoras do processo de extinção dessa espécie

The chloroplast matK gene has been identified as a rapidly evolving gene at nucleotide and corresponding amino acid levels. The high number of nucleotide substitutions and length mutations in matK has provided a strong phylogenetic signal for resolving plant phylogenies at various taxonomic levels. However, these same features have raised questions as to whether matK produces a functional protein product. matK is the only proposed chloroplast-encoded group II intron maturase. There are 15 genes in the chloroplast that would require a maturase for RNA splicing. Six of these genes have introns that are not excised by a nuclear imported maturase, leaving MatK as the only candidate for processing introns in these genes. Very little research has been conducted concerning the expression and function of this important gene and its protein product. It has become crucial to understand matK expression in light of its significance in RNA processing and plant systematics. In this study, we examined the expression, function and evolution of MatK using a combination of molecular and genetic methods. Our findings indicate that matK RNA and protein is expressed in a variety of plant species, and expression of MatK protein is regulated by development. In addition, matK RNA levels are affected by light. Furthermore, genetic analysis has revealed that although MatK has a high rate of amino acid substitution, these substitutions are not random but are constrained to maintain overall chemical structure and stability in this protein. We have also identified an alternate start codon for matK in some plant species that buffers indels (insertions and deletions) in the open reading frame (ORF) that are not in multiples of three in the gene sequence. Usually, indels not in multiples of three result in frame shifts that destroy the reading frame. Our results indicate that an out-of-frame matK start codon in some orchids compensates for these otherwise deleterious indels. This research represents the first in-depth analysis of matK gene expression and contributes to several fields of biology including plant systematics, genetics and gene expression. / Ph. D.

Gametophytic selection was examined as a breeding tool in developing Phalaenopsis hybrids that are more cool or warm temperature tolerant. Two hybrid Phalaenopsis, P. (Taisoco Windian à Sogo Sogo Yukidian) by P. hybrid unknown, were reciprocally cross-pollinated and exposed to 14°C/9°C for 7 days as a cold pollination treatment. Plants were pollinated again and exposed to 30°C/25°C for 3 days for the warm pollination treatment. Each cultivar was placed in either of two growth chambers during the pollination treatments and exposed to the selected temperatures, an 11-h photoperiod with an irradiance of 180 Mmol·m-2·s-1 and a relative humidity of 70%. The plants were returned to the greenhouse after pollination and the green capsules were collected after 150 days. Seeds obtained from these treatments were surface-sterilized and equal volumes were placed on Phytamax® medium. Evaluation of protocorm development was done after 73 days on a thermogradient table ranging from 10 to 30ºC. For the first family for which reciprocal crosses were available, the number of protocorms per plate ranged from 0 in the coldest treatments to 290 at 28°C. For cold pollinated seeds, protocorm development was optimum at 22 and 28°C (means of 290 and 250 protocorms per plate, respectively) whereas the greatest protocorm development for warm pollinated seeds occurred at 20°C (103 protocorms per plate). Of the 1471 total protocorms obtained 1095 were from cold pollinations, whereas 376 were from the warm pollinations. Protocorms were evaluated for leaf and root formation 125 days after initial plating. Transfer to warm or cold incubators occurred as protocorms developed leaves and roots. Seedlings were finally transferred to dried sphagnum and placed in growth chambers set to original pollination temperatures. One year after initial plating seedlings were evaluated on the following criteria: wet weight, number of leaves, leaf area, number of roots, and root length. The pollination treatment significantly affected the number of roots per seedling whereas germination temperature during germination significantly affected the weight (g). Weight of the seedlings, number of roots and the average root length were significantly affected by the interaction between pollination treatment and germination temperature. The weight, number of leaves, and average root length were significantly affected by the interaction between pollination treatment and incubator/growth chamber. These differences indicated that seedlings derived from warm pollination were more vigorous under warm growing conditions and those derived from cold pollination were more vigorous under cold growing conditions. The significance of the interaction between pollination treatment and incubator/growth chamber indicates that gametophytic selection for thermotolerance in Phalaenopsis can be successfully used as a plant breeding tool. Additional replication is required to confirm the greater germinability of seed derived from pollination occurring over a greater range of temperatures. / Master of Science

O ambiente epifítico é considerado um dos habitats mais desafiadores para as plantas, pois a disponibilidade hídrica e nutricional pode ser bastante escassa. Além disso, as plantas que colonizam este ambiente estão mais expostas aos fatores ambientais, dentre eles a luminosidade se mostra bastante importante, uma vez que esta atua tanto como fonte de energia na fotossíntese quanto como sinal ambiental em repostas fotomorgênicas. Sabe-se, por exemplo, que a luz exerce forte influência sobre a morfogênese radicular de plantas em geral, porém impacta ainda mais o desenvolvimento de orquídeas epífitas, dada a frequente exposição de suas raízes aéreas à incidência luminosa. Tendo em vista que a auxina ácido indolil-3-acético (AIA), o ácido abscísico (ABA) e o etileno são moduladores cruciais no controle da arquitetura radicular na maioria das plantas, sendo também mediadores chave em várias respostas fotomorfogênicas, este estudo propôs-se a investigar o possível envolvimento destes hormônios durante diferentes respostas morfo-fisiológicas desencadeadas pela exposição à luz do sistema radicular de plantas de C. fimbriatum. A ausência de incidência luminosa sobre às raízes resultou em maiores taxas de crescimento e volume radicular, porém, com menor acúmulo de biomassa em relação às raízes expostas à luz. O incremento na biomassa em raízes expostas à luz esteve correlacionado ao espessamento da parede celular na região cortical, o qual ocorreu em resposta especificamente à luz azul. Em termos gerais, a exposição das raízes à luz induziu o aumento nos níveis de AIA e ABA, enquanto que os teores de ACC foram superiores em raízes protegidas da incidência luminosa. Estes resultados sugerem que a luz pode modular o desenvolvimento radicular de C. fimbriatum através de um fino controle hormonal que depende de ajustes coordenados dos níveis de AIA ABA e ACC. Também foi investigado o potencial envolvimento das auxinas e do ABA durante a remobilização de carboidratos entre pseudobulbos e folhas de plantas que tiveram seus sistemas radiculares expostos à (ou protegidos da) luz. Os resultados revelaram que a manutenção das raízes sob condições de escuro levou ao aumento dos teores de AIA e de todas as fontes de carbono estudadas (especialmente de glicose e frutose) nos pseudobulbos, enquanto que as raízes cobertas apresentaram apenas um leve aumento no conteúdo de AIA. O tratamento concomitante das raízes com a condição de escuro e a aplicação de um inibidor do transporte polar de auxina causou uma diminuição abrupta nos teores de AIA em todos os órgãos analisados e a elevação do conteúdo de ABA no sistema radicular. De maneira interessante, essa última condição experimental induziu um conspícuo acúmulo de carboidratos nos pseudobulbos, principalmente de sacarose. Assim, os dados deste trabalho reforçam a importante participação do AIA e ABA como possíveis mediadores da sinalização desencadeada pela luz incidente no sistema radicular de C. fimbriatum, cujas respostas induzidas regulam não somente a morfogênese de tecidos radiculares, mas também influenciam na regulação da partição de carbono no sistema caulinar por meio de um provável mecanismo de sinalização à longa distância / The epiphytic environment is considered one of the most challenging for plants, due to frequent scarcity of water and nutrients. Furthermore, the plants that colonized this biotope are usually more exposed to the environmental cues. Light is considered one of the most important signals controlling plant development because it can act as both an energy source for photosynthesis and an environmental signal for photomorphogenic responses. Besides, light can influence the root morphology of most plants, with even stronger impacts expected in aerial roots of epiphytic orchids due their frequent exposition to direct light. Since indole-3-acetic acid (IAA), abscisic acid (ABA) and ethylene are crucial hormonal signals modulating the root architecture in most plant species, and key mediators during numerous photomorphogenic responses, this study investigated the potential involvement of these hormones in different morpho-physiological responses regulated by either the darkness treatment or the light exposure of Catasetum fimbriatum root system. The absence of light incidence on the roots resulted in higher root volume and growth rate, but lower dry mass accumulation than the light-exposed ones. The higher accumulation of biomass in the light-exposed roots was closed correlated with a more intense cell wall thickening in the root cortex, which appeared to be specifically induced by the blue light. In general, root exposure to light induced increasing levels of ABA and AIA, while the ACC content was higher in roots protected from light. This suggests that light might modulate C. fimbriatum root development through a fine-tuned hormonal mediation, which depends on coordinated adjustments of IAA, ABA and ACC levels. This study also investigated the potential involvement of auxin and ABA during the (re)mobilization of carbohydrates in pseudobulbs and leaves of plants that had their root systems either exposed to (or protected from) light. The results revealed that covering the roots increased in pseudobulbs the levels of AIA and all carbon sources studied (specially glucose and fructose), while the covered roots showed slightly higher levels of AIA. The concomitant treatment with NPA and root covering caused a sharp decrease of AIA levels in all organs and an ABA increase in the root system. Interestingly, this last condition induced a conspicuous carbohydrate accumulation in pseudobulbs, with sucrose as the predominant form. The data obtained in this study reinforce the remarkable participation of IAA and ABA as possible mediators of the signaling cascades triggered by the light incidence on C. fimbriatum root system, which was capable of inducing photomorphogenic responses not only in root tissues, but was also able to influence the carbon portioning in the shoot system by a potential long-distance signaling mechanism

As orquídeas terrestres estão distribuídas amplamente em ambientes tropicais e temperados do mundo. O habitat terrestre, para orquídeas, engloba distintas formações vegetais, como florestas, savanas, campos e banhados. Neste estudo consideramos, para a estimativa da amplitude e da ocorrência destas plantas, nove tipos de florestas no estado do Rio Grande do Sul no sul do Brasil, localizadas totalmente em latitudes subtropicais. Revisamos amostras de espécimes depositadas em sete herbários regionais e atualizamos a identificação das espécies para as circunscrições genéricas atuais. Com base nas localizações das amostras estimamos dois parâmetros de amplitude, nomeados extensão de ocorrência e área de ocupação, objetivando determinar o estado de conservação das espécies de acordo com as categorias da IUCN. Como resultado, encontramos 22 gêneros e 50 espécies, a maioria dos gêneros (15) possui apenas uma espécie no estado. Os gêneros mais diversificados foram Cyclopogon, Aspidogyne e Malaxis, com 14, oito e quatro espécies, respectivamente. Outros quatro gêneros apresentaram três (Pelexia) ou duas (Habenaria, Prescottia, e Sarcoglottis) espécies nos ambientes florestais. As estimativas de amplitude, especialmente a área de ocupação, resultaram em um elevado número de espécies ameaçadas. Espécies criticamente ameaçadas, considerando a extensão de ocorrência, estão distribuídas em sete gêneros e 18 espécies. O tipo de floresta mais diversificado foi a floresta estacional da Serra Geral, seguido pela floresta Atlântica e pela floresta estacional do Escudo Cristalino. Um total de 19 espécies ocorreu somente em uma formação e apenas quatro espécies ocorreram em seis ou sete tipos de florestas. O número de registros neste estudo mostrou que as orquídeas terrestres em ambientes florestais são um grupo subamostrado, que possuem poucas coletas e são pouco avaliadas em estudos ecológicos com populações e comunidades de sub-bosque. Mais estudos são necessários para determinar com maior precisão a extensão de ocorrência, o tamanho das populações, e o estado real de conservação das espécies nativas. / Terrestrial orchids occur widespread in tropical and temperate environments around the world. The terrestrial habitat for orchid species comprises several distinct plant formations, like forests, woodlands, grasslands and wetlands. In this study we focused the estimation of range sizes and the occurrence of these plants in nine forest types in the South Brazilian state of Rio Grande do Sul, located entirely in subtropical latitudes. We revised sampled specimens deposited in seven regional herbaria and updated species identifications to current generic circumscriptions. Based on sampling locations we estimated two range size parameters, namely extent of occurrence and area of occupancy, aiming to determine the conservation status according to IUCN categories. As a result we found 22 genera and 50 species, most genera (15) having of them a single species in the state. The most diversified genera were Cyclopogon, Aspidogyne and Malaxis, with 14, eight and four species, respectively. Four additional genera presented three (Pelexia) or two (Habenaria, Prescottia, and Sarcoglottis) species in forest environments. Range size estimations, especially through area of occupancy, resulted in an outstanding number of threatened species. Critically endangered species according to extent of occurrence were distributed in seven genera and 18 species. The most diversified forest types were the central Serra Geral seasonal forests, followed by the Atlantic rainforest and the southeast Crystalline Shield seasonal forests. A total of 19 species occurred in a single forest formation and only four species occurred widespread in six or seven forest types. The number of recordings in this study showed to be exponentially related to species range according to forest types. Our study showed that terrestrial orchids in forest environments are an overlooked plant group, which has been poorly sampled and poorly evaluated in ecological studies concerning understory populations and communities. Further studies are necessary to determine more precisely the extent of occurrence, the size of populations, and the real conservation status of native species.

As orquídeas terrestres estão distribuídas amplamente em ambientes tropicais e temperados do mundo. O habitat terrestre, para orquídeas, engloba distintas formações vegetais, como florestas, savanas, campos e banhados. Neste estudo consideramos, para a estimativa da amplitude e da ocorrência destas plantas, nove tipos de florestas no estado do Rio Grande do Sul no sul do Brasil, localizadas totalmente em latitudes subtropicais. Revisamos amostras de espécimes depositadas em sete herbários regionais e atualizamos a identificação das espécies para as circunscrições genéricas atuais. Com base nas localizações das amostras estimamos dois parâmetros de amplitude, nomeados extensão de ocorrência e área de ocupação, objetivando determinar o estado de conservação das espécies de acordo com as categorias da IUCN. Como resultado, encontramos 22 gêneros e 50 espécies, a maioria dos gêneros (15) possui apenas uma espécie no estado. Os gêneros mais diversificados foram Cyclopogon, Aspidogyne e Malaxis, com 14, oito e quatro espécies, respectivamente. Outros quatro gêneros apresentaram três (Pelexia) ou duas (Habenaria, Prescottia, e Sarcoglottis) espécies nos ambientes florestais. As estimativas de amplitude, especialmente a área de ocupação, resultaram em um elevado número de espécies ameaçadas. Espécies criticamente ameaçadas, considerando a extensão de ocorrência, estão distribuídas em sete gêneros e 18 espécies. O tipo de floresta mais diversificado foi a floresta estacional da Serra Geral, seguido pela floresta Atlântica e pela floresta estacional do Escudo Cristalino. Um total de 19 espécies ocorreu somente em uma formação e apenas quatro espécies ocorreram em seis ou sete tipos de florestas. O número de registros neste estudo mostrou que as orquídeas terrestres em ambientes florestais são um grupo subamostrado, que possuem poucas coletas e são pouco avaliadas em estudos ecológicos com populações e comunidades de sub-bosque. Mais estudos são necessários para determinar com maior precisão a extensão de ocorrência, o tamanho das populações, e o estado real de conservação das espécies nativas. / Terrestrial orchids occur widespread in tropical and temperate environments around the world. The terrestrial habitat for orchid species comprises several distinct plant formations, like forests, woodlands, grasslands and wetlands. In this study we focused the estimation of range sizes and the occurrence of these plants in nine forest types in the South Brazilian state of Rio Grande do Sul, located entirely in subtropical latitudes. We revised sampled specimens deposited in seven regional herbaria and updated species identifications to current generic circumscriptions. Based on sampling locations we estimated two range size parameters, namely extent of occurrence and area of occupancy, aiming to determine the conservation status according to IUCN categories. As a result we found 22 genera and 50 species, most genera (15) having of them a single species in the state. The most diversified genera were Cyclopogon, Aspidogyne and Malaxis, with 14, eight and four species, respectively. Four additional genera presented three (Pelexia) or two (Habenaria, Prescottia, and Sarcoglottis) species in forest environments. Range size estimations, especially through area of occupancy, resulted in an outstanding number of threatened species. Critically endangered species according to extent of occurrence were distributed in seven genera and 18 species. The most diversified forest types were the central Serra Geral seasonal forests, followed by the Atlantic rainforest and the southeast Crystalline Shield seasonal forests. A total of 19 species occurred in a single forest formation and only four species occurred widespread in six or seven forest types. The number of recordings in this study showed to be exponentially related to species range according to forest types. Our study showed that terrestrial orchids in forest environments are an overlooked plant group, which has been poorly sampled and poorly evaluated in ecological studies concerning understory populations and communities. Further studies are necessary to determine more precisely the extent of occurrence, the size of populations, and the real conservation status of native species.

As orquídeas terrestres estão distribuídas amplamente em ambientes tropicais e temperados do mundo. O habitat terrestre, para orquídeas, engloba distintas formações vegetais, como florestas, savanas, campos e banhados. Neste estudo consideramos, para a estimativa da amplitude e da ocorrência destas plantas, nove tipos de florestas no estado do Rio Grande do Sul no sul do Brasil, localizadas totalmente em latitudes subtropicais. Revisamos amostras de espécimes depositadas em sete herbários regionais e atualizamos a identificação das espécies para as circunscrições genéricas atuais. Com base nas localizações das amostras estimamos dois parâmetros de amplitude, nomeados extensão de ocorrência e área de ocupação, objetivando determinar o estado de conservação das espécies de acordo com as categorias da IUCN. Como resultado, encontramos 22 gêneros e 50 espécies, a maioria dos gêneros (15) possui apenas uma espécie no estado. Os gêneros mais diversificados foram Cyclopogon, Aspidogyne e Malaxis, com 14, oito e quatro espécies, respectivamente. Outros quatro gêneros apresentaram três (Pelexia) ou duas (Habenaria, Prescottia, e Sarcoglottis) espécies nos ambientes florestais. As estimativas de amplitude, especialmente a área de ocupação, resultaram em um elevado número de espécies ameaçadas. Espécies criticamente ameaçadas, considerando a extensão de ocorrência, estão distribuídas em sete gêneros e 18 espécies. O tipo de floresta mais diversificado foi a floresta estacional da Serra Geral, seguido pela floresta Atlântica e pela floresta estacional do Escudo Cristalino. Um total de 19 espécies ocorreu somente em uma formação e apenas quatro espécies ocorreram em seis ou sete tipos de florestas. O número de registros neste estudo mostrou que as orquídeas terrestres em ambientes florestais são um grupo subamostrado, que possuem poucas coletas e são pouco avaliadas em estudos ecológicos com populações e comunidades de sub-bosque. Mais estudos são necessários para determinar com maior precisão a extensão de ocorrência, o tamanho das populações, e o estado real de conservação das espécies nativas. / Terrestrial orchids occur widespread in tropical and temperate environments around the world. The terrestrial habitat for orchid species comprises several distinct plant formations, like forests, woodlands, grasslands and wetlands. In this study we focused the estimation of range sizes and the occurrence of these plants in nine forest types in the South Brazilian state of Rio Grande do Sul, located entirely in subtropical latitudes. We revised sampled specimens deposited in seven regional herbaria and updated species identifications to current generic circumscriptions. Based on sampling locations we estimated two range size parameters, namely extent of occurrence and area of occupancy, aiming to determine the conservation status according to IUCN categories. As a result we found 22 genera and 50 species, most genera (15) having of them a single species in the state. The most diversified genera were Cyclopogon, Aspidogyne and Malaxis, with 14, eight and four species, respectively. Four additional genera presented three (Pelexia) or two (Habenaria, Prescottia, and Sarcoglottis) species in forest environments. Range size estimations, especially through area of occupancy, resulted in an outstanding number of threatened species. Critically endangered species according to extent of occurrence were distributed in seven genera and 18 species. The most diversified forest types were the central Serra Geral seasonal forests, followed by the Atlantic rainforest and the southeast Crystalline Shield seasonal forests. A total of 19 species occurred in a single forest formation and only four species occurred widespread in six or seven forest types. The number of recordings in this study showed to be exponentially related to species range according to forest types. Our study showed that terrestrial orchids in forest environments are an overlooked plant group, which has been poorly sampled and poorly evaluated in ecological studies concerning understory populations and communities. Further studies are necessary to determine more precisely the extent of occurrence, the size of populations, and the real conservation status of native species.