Diversidad florística presente en turberas de musgo Sphagnum en la cuenca del río Mayer, comuna de O’Higgins, región Aysén, Chile

Las turberas de Sphagnum son humedales de alto valor ambiental y son frecuentes en la Patagonia. En particular en la región de Aysén, los estudios sobre su diversidad aún son insuficientes y parciales. En este trabajo se evalúa la variabilidad de la composición y abundancia florística, presente en cuatro turberas de musgo Sphagnum continentales, sin intervención humana. Se establecieron 40 subparcelas de 1 m2 de manera aleatoria, a fin de determinar diferencias entre ellas; se estimó el índice de diversidad de Shannon- Wiener (H’), el índice de Simpson (D), el índice exponencial de entropía de Shannon (exp H’) y el índice inverso de Gini-Simpson (1/1-?’). Con los datos obtenidos se realizó la prueba de Kruskal- Wallis con la corrección de Bonferroni, para detectar diferencias entre las turberas, debido a que los datos no mostraron distribución normal (prueba de Shapiro-Wilk). Además, se aplicó un análisis exploratorio de componentes principales (PCA) con el fin de inferir las relaciones existentes entre las especies con algún gradiente ecológico. Un total de 33 taxones, 21 familias y 27 géneros fueron identificados. Las especies más dominantes fueron: Sphagnum magellanicum (Brid.) y Empetrum rubrum Vahl ex Willd. El índice de diversidad de Shannon-Wiener (H’) varió entre 1,47 a 0,96, el índice de Simpson (D) entre 0,48 a 0,30, el índice exponencial de entropía de Shannon (exp H’) entre 4,46 a 2,66 y el índice inverso de Gini-Simpson (1/1-?’) entre 0,52 a 0,69. El PCA sugiere la existencia de un gradiente florístico relacionado a la hidrología.

Ultraviolet absorbance of Sphagnum magellanicum, S. fallax and S. fuscum extracts with seasonal and species-specific variation

Bryophytes, including Sphagnum, are common species in alpine and boreal regions especially on mires, where full sunlight exposes the plants to the damaging effects of UV radiation. Sphagnum species containing UV-protecting compounds might offer a biomass source for nature-based sunscreens to replace the synthetic ones. In this study, potential compounds and those linked in cell wall structures were obtained by using methanol and alkali extractions and the UV absorption of these extracts from three common Sphagnum moss species Sphagnum magellanicum, Sphagnum fuscum and Sphagnum fallax collected in spring and autumn from western Finland are described. Absorption spectrum screening (200–900 nm) and luminescent biosensor (Escherichia coli DPD2794) methodology were used to examine and compare the protection against UV radiation. Additionally, the antioxidant potential was evaluated using hydrogen peroxide scavenging (SCAV), oxygen radical absorbance capacity (ORAC) and ferric reducing absorbance capacity (FRAP). Total phenolic content was also determined using the Folin-Ciocalteu method. The results showed that methanol extractable compounds gave higher UV absorption with the used methods. Sphagnum fallax appeared to give the highest absorption in UV-B and UV-A wavelengths. In all assays except the SCAV test, the methanol extracts of Sphagnum samples collected in autumn indicated the highest antioxidant capacity and polyphenol content. Sphagnum fuscum implied the highest antioxidant capacity and phenolic content. There was low antioxidant and UV absorption provided by the alkali extracts of these three species.

Impacts of intraspecific variability and local adaptation on the ecophysiology of mosses: an example with Sphagnum magellanicum

BackgroundBryophytes are a diverse plant group and are functionally different from vascular plants. Yet, plant ecology theories and hypotheses are often presented in an inclusive term. The trait-based approach to ecology is no exception; largely focusing on vascular plant traits and almost exclusively on interspecific traits. Currently, we lack information about the magnitude and the importance of intraspecific variability to the ecophysiology of bryophytes and how these might translate to local adaptation—a prerequisite for adaptive evolution.MethodWe used transplant and factorial experiments involving moisture and light to ask whether variability in traits between morphologically distinct individuals of Sphagnum magellanicum from habitat extremes was due to phenotypic plasticity or local adaptation and the implications for the ecophysiology of the species.Key ResultsWe found that the factors that discriminated between the plant origins in the field did not translate to their ecophysiological functioning and the pattern of variability changed with the treatments, which suggests that the trait responses were due largely to phenotypic plasticity. The trait responses suggest that the need for mosses to grow in clumps where they maintain a uniform growth rate may have an overriding effect on responses to environmental heterogeneity, and therefore a constraint for local adaptation.ConclusionThe circumstances under which local adaptation would be beneficial in this plant group is not clear. We conclude that extending the trait-based framework to mosses or making comparisons between mosses and vascular plants under any theoretical framework would only be meaningful to the extent that growth form and dispersal strategies are considered.

Contribution to the knowledge of the oribatid mite genus Zeasuctobelba (Acari, Oribatida, Suctobelbidae)

A new species of Zeasuctobelba (Oribatida, Suctobelbidae) is described from a moss Sphagnum magellanicum in swamp in southern Chile. Zeasuctobelba processa sp. nov. differs from all species of the genus by the presence of a median process on the anterior margin of the ventral plate (anterior part of epimere I), lateral sides of prodorsum with one pair of strong triangular processes and by bothridial setae having long setiform apices and long cilia. Revised generic diagnosis, identification key and data on distribution of known species of Zeasuctobelba are presented. Zeasuctobelba nodosa Hammer, 1966 and Z. arcuata Hammer, 1968 are excluded from Zeasuctobelba.

Знахідка Drosera rotundifolia L. біля озера Святого (Хмельницька область)

У статті повідомляється про знахідку Drosera rotundifolia L. у межах заболочених берегів території гідрологічної пам’ятки природи загальнодержавного значення – озера Святе, що увійшла в НПП «Мале Полісся» Хмельницької області. Наведено результати геоботанічних, фітоценотичних досліджень, екології місцезростання виду. Рослинність представлено формаціями Sphagneta magellanicum, Sphagnetа cuspidatum, які утворюють асоціації Sphagnum magellanicum + Carex rostrata + Sphagnum cuspidatum + Ledum palustre + Calla palustris + Drosera rotundifolia. Висвітлено дані про чисельність особин у ценопопуляції на моніторинговій території. Отримані дані засвідчують сприятливі умови для подальшого розвитку та самопідтримання популяцій у ценозі. Також виявлено зростання Scheuchzerіa palustris L., яка занесена до Червоної книги України.