Resumo O incremento do desmatamento em florestas tropicais tem causado uma perda severa de habitats e fragmentação da paisagem. As respostas das espécies a esses impactos antrópicos indicam alteração na diversidade e composição das comunidades de espécies e têm sido estudadas para vários grupos de plantas. Como esses impactos afetam a comunidade de samambaias e licófitas, no entanto, é menos conhecido. Neste estudo, avaliamos os efeitos da perda e fragmentação de habitat em samambaias e licófitas em florestas não inundadas de terras baixas na Amazônia equatoriana (bacia amazônica ocidental). Obtivemos informações da comunidade de treze parcelas localizadas em um gradiente de fragmentação (medido por um índice de fragmentação da paisagem: o fragindex) e usamos índices de comunidade e diversidade para avaliar as respostas das espécies. Encontramos 3.824 indivíduos de 55 espécies de samambaias e licófitas. A parcela com o maior valor de fragindex (mais de 20% de perda e fragmentação de habitat) teve a menor diversidade, mas a maior diversidade foi encontrada em parcelas com valores de fragindex entre 12% e 21% e não nas parcelas em paisagens sem desmatamento. Embora a composição da comunidade tenha variado ao longo do gradiente do fragindex, a renovação de espécies não foi significativamente relacionada a esse índice. Esses resultados sugerem que as mudanças na paisagem causadas pelo desmatamento alteram a disponibilidade de habitats, afetando consequentemente os padrões de distribuição de samambaias e licófitas. plantas entanto conhecido estudo bacia ocidental. ocidental . ocidental) medido 3824 3 824 3.82 5 mais 20 12 21 382 82 3.8 2 1 38 8 3.

Abstract Tropical forests have been subjected to increasing deforestation, leading to severe habitat loss and fragmentation of the landscape. Studies of various plant groups-indicate alteration in species diversity and assemblage composition in response to these impacts. How theses impacts affect ferns and lycophytes, however, is less well known. In this study we evaluate the effects of habitat loss and fragmentation on ferns and lycophytes in lowland non-inundated forests in Ecuadorian Amazonia. We obtained assemblage information from thirteen plots located in gradients of habitat loss and fragmentation (as measured by the landscape fragmentation index: fragindex) and used community and diversity indices to evaluate species responses. We found 3,824 individuals of 55 species. The plot with the highest fragindex value (more than 20% of habitat loss and fragmentation) had the lowest diversity, but the highest diversity was found in plots with fragindex values from 12% to 21% of habitat loss and fragmentation rather than in the landscapes without deforestation. Although community composition varied along the fragindex gradient, species turnover was not significantly related to this index. These results suggest that changes in the landscape caused by deforestation alter the availability of habitats, consequently affecting the distribution patterns of ferns and lycophytes. groupsindicate groups indicate however known noninundated non inundated Amazonia as index responses 3824 3 824 3,82 5 more 20 12 21 gradient habitats 382 82 3,8 2 1 38 8 3,

ABSTRACT The northeastern slope of the Andes is an area of high diversity of ferns and lycophytes. In this study we assessed the diversity patterns of ferns and lycophytes in ten 250 m x 2 m plots installed at three elevational zones, from 418 to 3447 m.a.s.l., in the Napo province of Ecuador. Floristic diversity was measured using Hill numbers and by partitioning species diversity. Three functional diversity indices were calculated from a set of five leaf traits and weighted by species abundance: functional richness (FRic), evenness (FEve) and divergence (FDiv). To disentangle functional diversity from species richness, the standardized effect size (SES) of each index was also calculated. We recorded 148 species, Polypodiaceae and Dryopteridaceae being the most representative families. Species richness continuously decreased with elevation. Floristic composition was highly heterogeneous among elevation zones, with total species turnover found between 1500 and 2000 m.a.s.l. SES-FDiv and SES-FEve were higher than the null expectation for plots at mid-elevations, suggesting that deterministic mechanisms, such as biotic or abiotic filters, could explain assemblage composition at these sites. However, SES-FEve, SES-FRic and SES-FDiv did not differ from the null expectations at low and high elevation sites, suggesting the predominance of a stochastic process. By combining floristic and functional diversity, we were able to infer the observed community patterns with the resource-use strategies of fern and lycophytes in a mountain area, an approach that can be used to understand how assemblages might react to changing environmental conditions.

RESUMEN La vertiente noreste de los Andes del Ecuador tiene alta diversidad de helechos y licófitos. En este estudio describimos patrones de diversidad de estos grupos en diez parcelas de 250 m x 2 m instaladas en tres zonas altitudinales, de 418 a 3447 m.s.n.m., en la provincia de Napo, Ecuador. La diversidad se calculó utilizando los números de Hill y particionando la diversidad de especies. Tres índices de diversidad funcional fueron estimados a partir de cinco atributos de las hojas ponderados por la abundancia de las especies: riqueza (FRic), uniformidad (FEve) y divergencia (FDiv). Para separar la diversidad funcional de la riqueza, se calculó el tamaño del efecto estandarizado (SES) de cada índice. Registramos 148 especies, siendo Polypodiaceae y Dryopteridaceae las familias más representativas. La riqueza disminuyó continuamente en el gradiente altitudinal. La composición de la comunidad tuvo un cambio total de especies entre 1500 y 2000 m.s.n.m. En parcelas intermedias, SES-FDiv y SES-FEve registraron valores más altos de lo esperado por el modelo nulo, lo que sugiere que los mecanismos deterministas, como los filtros bióticos y abióticos, podrían explicar el ensamble en estas comunidades. En parcelas de altitudes bajas y altas los tres índices no difirieron del valor nulo, lo que sugiere que predominan procesos estocásticos. Al combinar composición florística y diversidad funcional, pudimos identificar patrones de diversidad y estrategias de uso de recursos de helechos y licófitos. Este enfoque se puede utilizar para comprender cómo el ensamble de las comunidades es afectado por la variación en las condiciones ambientales.

Abstract: Background and Aims: Light and water are resources that limit the germination and growth of vascular plants in forests and the establishment process significantly influence the species distribution. For this reason, we evaluated whether sympatric ferns Blechnum appendiculatum and B. schiedeanum (Blechnaceae) differ in habitat preference and if their germination requirements may help explain their distribution in a mountain mesophyllous forest. Methods: Spores were exposed to light quality, amount of light and water potential treatments. The frequency of sporophytes of both species and the proportion of light received in the forest was also recorded. Key results: It was found that both species did not germinate in darkness and few spores did so with far-red wavelength compared to white light. The spore sprout was promoted with the increase of light intensity, and 0.04 µmol m-2 s-1 light was sufficient so this was more than 60% in both species. The decrease in water availability reduced the germination, but B. appendiculatum showed greater ability to withstand water scarcity to -1.05 MPa. Blechnum schiedeanum was abundant in environments with relatively closed canopy while B. appendiculatum occurred more frequently on the forest border. Conclusions: Germination requirements were partially related to habitat preference of the species. Blechnum schiedeanum seems to be more shade tolerant than B. appendiculatum.

Resumen: Antecedentes y Objetivos: La luz y el agua son recursos que limitan la germinación y el crecimiento de las plantas en los bosques, y el establecimiento influye importantemente en la distribución de las especies. Por tal razón se evaluó si los helechos simpátricos Blechnum appendiculatum y B. schiedeanum (Blechnaceae) difieren en la preferencia de hábitat y si los requerimientos en la germinación podrían ayudar a explicar su distribución en un bosque mesófilo de montaña. Métodos: Las esporas se expusieron a tratamientos de calidad de luz, cantidad de luz y potencial hídrico. También se registró la frecuencia de esporofitos de ambas especies y la proporción de luz recibida en el bosque. Resultados clave: Ambas especies no germinaron en oscuridad y pocas esporas lo hicieron con luz rojo-lejana, en comparación con luz roja y blanca. El brote de la espora aumentó con la cantidad de luz recibida, y 0.04 µmol m-2 s-1 de luz fue suficiente para que en ambas especies éste fuese mayor a 60%. La disminución en la disponibilidad de agua redujo la germinación, pero B. appendiculatum mostró mayor capacidad para soportar la escasez hídrica a -1.05 MPa. En ambientes con dosel relativamente cerrado fue abundante B. schiedeanum, mientras que B. appendiculatum ocurrió con mayor frecuencia en ambientes abiertos. Conclusiones: Los requerimientos para la germinación de la espora se relacionaron parcialmente con la preferencia del hábitat de las especies. Blechnum schiedeanum parece ser más tolerante a la sombra que B. appendiculatum.