Learning of recursive functions refutably informally means that for every recursive function, the learning machine has either to learn this function or to refute it, that is to signal that it is not able to learn it. Three modi of making precise the notion of refuting are considered. We show that the corresponding types of learning refutably are of strictly increasing power, where already the m...

Abstract A floristic inventory and a taxonomic treatment of Asteraceae from Serra da Confusão do Rio Preto in the state Goiás are provided. Collections were carried out July 2017 to December 2018 fragment cerrado sensu stricto with transition rupestre (rocky cerrado), for total 38 expeditions covering all seasons. Taxonomic resulting specimens includes identification keys, diagnoses description...

Globally, temperate deciduous forests are threatened by invasion of non-native (exotic) plant species. In the eastern United States, Rosa multiflora is a dominant shrub invader in forests, which often forms dense thickets that reduce sunlight availability understory, where decreased native diversity and abundance observed. Management restoration difficult but desirable, especially when intensit...

In West Africa, more than 80% of the original forest cover has disappeared due to exponential growth human populations in a recurrent search for new agricultural land. Once fertility land is exhausted, these areas are abandoned and left be reforested through natural succession. Despite widespread presence secondary forests various ages African landscapes, little known about trajectories recover...

Abstract The coastal region of the municipalities Curuçá and Maracanã, on northeastern coast Pará, shelters a valuable biological heritage, last two remnants Dense Rain Forest shores Atlantic Ocean. On Ipomonga Island (Curuçá) at Marieta Beach (Maracanã), Lowland is notable for its abrupt contact with pioneer formation marine influence, called as Restinga. This geomorphological interface favors...

Dzungarian Alatau mountain is a unique place of agrobiodiversity concentration. The apple forests consisted the red book species Malus sieversii (Ledeb.) M. Roem. in combination with Abies sibirica Ledeb. and Populus tremula L. form pronounced altitudinal-climatic band within 1200-1600 m Alatau. In this article features floristic composition communities four gorges Zhongar-Alatau National Park ...

We present the first analysis of riparian vegetation types on the Arctic Slope of Alaska including classification and ordination. We classified riparian willow communities according to the Braun-Blanquet approach, and analysed environmental relationships of associations to complex environmental gradients using Detrended Correspondence Analysis. We also examined synecological differences in term...

A working checklist of accepted taxa worldwide is vital in achieving the goal of developing an online flora of all known plants by 2020 as part of the Global Strategy for Plant Conservation. We here present the first-ever worldwide checklist for liverworts (Marchantiophyta) and hornworts (Anthocerotophyta) that includes 7486 species in 398 genera representing 92 families from the two phyla. The...