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Himatanthus sucuuba é uma espécie arbórea de reputado valor fitoterápico, que coloniza regiões de várzea e de terra firme na Amazônia Central. Objetivou-se verificar durante quatro meses, em casa de vegetação, a germinação e o desenvolvimento inicial de plântulas da espécie, oriundas de sementes dos dois diferentes ecossistemas. Não houve diferença significativa em relação ao peso de matéria seca de sementes da várzea e da terra firme. Entretanto, a taxa de germinação da espécie variou de acordo com o substrato e o local de procedência das sementes. No substrato areia+serragem (não-alagado) a germinação da espécie foi alta, independente do ambiente (várzea 94% e terra firme 91%). No substrato constituído apenas por água (alagado), as sementes provenientes da várzea tiveram a maior taxa de germinação (96%) e de formação de plântulas (84%), quando relacionadas às da terra firme, que apresentaram taxa de germinação de 64%, e nenhuma das sementes germinadas formou plântulas. Neste tratamento foi verificado o apodrecimento da radícula poucos dias após sua emissão, indicando que as sementes oriundas da várzea apresentam características adaptativas ao ambiente inundado em relação às da mesma espécie oriundas da terra firme. Himatanthus sucuuba is a tree species with known phytotherapic value which colonizes both white-water floodplains (várzea) and upland forests (terra firme) in Central Amazonian. The objective of this study was to compare germination and initial seedling development from seeds collected in both the ecosystems. There was no significant difference between dry seed mass, but in a four month period in a glasshouse in Manaus, Brazil, germination rate differed according to the substrate and origin of the seeds. In the substrate sand + sawdust (non-flooded) germination rate was high, independent of seed origin (várzea 94% and terra firme 91%). In the substrate constituted only by water (flooded), the seeds originating from várzea had a higher germination rate (96%) and seedling formation (84%) than those originating from terra firme which had a germination rate of 64% and none of the seeds formed seedlings. In this treatment, the radicles rot few days after their emission, indicating that the seeds originating from várzea present adaptive characteristics to the floodplain environment which are not present in seeds from terra firme.

Inoculation with arbuscular mycorrhizal (AM) fungi has often promoted increased growth of plants but very little work has been done in the tropics to evaluate the effects of inoculation on the establishment and development of seedlings in forests. Desmoncus orthacanthos Martius is a scandent palm present both in early and late succession, and consequently can be used in restoration processes. A test was conducted to determine the effect of AM on the establishment of Desmoncus orthacanthos in tropical forest in the Yucatan Peninsula, Mexico. Thirty inoculated and 30 non-inoculated seedlings were introduced in two sites of different successional age, a mature forest and an eight-year old abandoned cornfield (acahual).Survival and growth parameters were evaluated after 12 months. Leaf area and phosphorus, but not height, were greater in inoculated than non-inoculated plants in the forest but not in the acahual. However, mycorrhizae had a clear effect on plant survival in both sites, with a threefold increase in survival of inoculated compared with non-inoculated plants bassed on an odds ratio. The results suggest that inoculation will be important to increase the establishment of this commercially important palm. Rev. Biol. Trop. 54(1): 65-72. Epub 2006 Mar 31.La inoculación con hongos micorrizógenos arbusculares (AM)promueve un incremento en el crecimiento de las plantas, sin embargo poco trabajo se ha realizado en los trópicos para evaluar el efecto de la inoculación en el proceso de establecimiento de plántulas. Desmoncus orthacanthos Martius es una palmera trepadora que se distribuye tanto en etapas tempranas y tardías de la sucesión, por lo tanto puede ser empleada en procesos de restauración. Se realizó una prueba de establecimiento de D. orthacanthos en una selva tropical de la península de Yucatán, México. Treinta plántulas inoculadas y 30 no inoculadas se establecieron en dos sitios con diferentes etapas sucesionales: selva madura y un campo abandonado de maíz (acahual). Después de 12 meses el valor de área foliar y contenido de fósforo fue mayor en el tratamiento con micorrizas en la selva pero no en el acahual, sin embargo, el tratamiento con micorrizas mostró un claro efecto en la supervivencia de las palmeras en ambos sitios con un incremento tres veces mayor en la probabilidad de supervivencia de palmeras inoculadas comparadas con las no inoculadas de acuerdo al análisis de razón de disparidad (odds ratio). La inoculación podría ser importante para incrementar el establecimiento de esta palmera.