Undergrowth

About: Undergrowth is a research topic. Over the lifetime, 795 publications have been published within this topic receiving 11911 citations. The topic is also known as: understorey & underbrush.

Habitat preferences of the native badger and the invasive raccoon dog in southern Finland

Abstract: We compared the habitat preferences of the alien raccoon dog Nyctereutes procyonoides (Gray, 1834) and the native badger Meles meles (Linnaeus, 1758) in two areas (Ruissalo and Tuulos) in southern Finland by radio-tracking the animals during summer from 2005 to 2008. We assumed that the habitat preferences of these two medium-sized carnivores differ to some extent (ie they are able to share the resources), because they have been sympatric for more than 50 years in southern Finland and populations of both species have increased during that period. The results indicated that the habitat preferences of these species are indeed different: raccoon dogs favoured meadows, gardens and open woodlands with tall and abundant undergrowth, whereas badgers favoured both pine forests and deciduous and mixed forests with thick canopy but sparse undergrowth. However, fields were favoured by both species in one study area (Tuulos). The results show that although both species are flexible in their habitat use and share some habitat preferences, the most favoured habitats differ between the species.

Distribution of primary forest plant species in a 19-year old secondary forest in French Guiana

Abstract: Secondary succession in a 19-y old tropical rainforest of French Guiana was investigated through the distribution pattern of primary forest species. The experimental plot of 25 ha was logged to simulate conditions of a paper pulp cut. Enumeration of all plants of height ≥ 50 cm in 52 subplots 10 m × 10 m indicated the number of species and individuals in five species categories; short-lived pioneer species, pioneer species that persist in mature forest, primary forest species capable of germinating in shade, primary forest species that indicate a preference for clearings (small gaps) in mature forest and understorey primary forest species. Change in proportion of the most abundant species (≥ 1 cm dbh) over the last 15 y indicated a decrease in short-lived pioneer species and an increase in pioneers that can persist in the mature forest. Proportion of species categories per height class indicated that primary forest species were mainly found in the lower height class in this forest which is largely dominated by secondary forest tree species forming a canopy that rarely exceeds 20 m. Individuals of primary forest species were encountered on ARBOCEL as sprouts from large stumps, sprouts from juveniles or as untraumatised saplings or juveniles. The distribution pattern in a 4-ha area of 11 selected primary forest canopy tree species revealed an overall trend in recolonisation of this species category in the secondary forest. Considered individually, the clustered distribution of stems of Eperua grandiflora showed the importance of regeneration through sprouting or remaining individuals. The gradient distribution, oriented from the edge to the centre of the studied plot, and displayed by the stem densities of Virola michelii, suggested a recent progressive dispersal of seeds. A more dynamic recolonisation front was observed for the primary forest understorey species Cassipourea guianensis and was probably linked to both the initial logging conditions and the fact that this species fruits when relatively young.

Evaporation and Soil Moisture in Relation to the Succession of Plant Associations ...

Abstract: 1. These data represent the evaporation rates in the lower aerial stratum and the range of soil moisture in the upper subterranean strata of the vegetation of the various associations, but these must be regarded as critical regions, since within them develop the seedlings which determine the character of succeeding vegetation. 2. Evaporation at different stations in the same plant association exhibits variations similar in character and degree. 3. The rate of evaporation in the cottonwood dune association, both by its great amount and by its excessive variation, seems a quite sufficient cause for the xerophytic character of the vegetation and for the absence of undergrowth, in spite of the constant presence of growth-water. 4. The pine and oak dune associations resemble one another closely both in their mean evaporation rates and in their supply of growth-water. The former is slightly more xerophytic during the midsummer weeks. 5. The vernal vegetation of the pine dune is quite as mesophytic as that of th...