scispace - formally typeset
Search or ask a question
Topic

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.


Papers
More filters
Journal ArticleDOI
TL;DR: The Xavantina-Cachimbo Expedition worked during 1967-9 in a 20 km square around a base camp (12 $ √circ$ 49' N, 51 $^\circ$ 46' W), ca. 260 km north of XAVANTINA (NE Mato Grosso) and near XAVANSA as mentioned in this paper.
Abstract: The Xavantina-Cachimbo Expedition worked during 1967-9 in a 20 km square around a base camp (12 $^\circ$ 49' N, 51 $^\circ$ 46' W), ca. 260 km north of Xavantina (NE Mato Grosso) and near Xavantina itself. The vegetation is of special interest because the base camp is situated near the junction of the savanna region of Central Brazil and the Amazonian forest. It is a pattern of savanna (cerrado), savanna woodland (cerradao), forest and treeless grassland (campo) with often remarkably abrupt boundaries between the different communities. Until 1967 the area had been very little affected by man. The climate is characterized by high temperature throughout the year, an annual rainfall of about 1200 to 1400 mm, and a more or less rainless dry season from June to September inclusive. During the dry season the cerrado, campo and some forms of cerradao vegetation are subject to fire, but are not burned every year. The forest, except the Deciduous Seasonal forest, is not normally burned. The rocks consist of sandstones overlying shale and mudstones. The sandstone weathers to form widespread dystrophic soils of low nutrient content, whilst the finer textured rocks, exposed in some deeper valleys, produce somewhat richer mesotrophic soils. The woody vegetation types of dystrophic soils are classified into three types of Evergreen Seasonal forest ('Swampy Gallery' forest, 'Valley' forest and 'Dry' forest), cerradao and cerrado. The Swampy Gallery forest is found along streams where the water table is close to the surface even in the dry season and is often bordered on one or both sides by strips of campo. In composition it resembles an impoverished Amazonian rain forest. The top-storey is dominated by Qualea ingens and Q. wittrockii, growing sometimes to 40 m, and the undergrowth includes numerous dicotyledons, Scitamineae, grasses and other monocotyledons. At a slightly higher level in stream valleys there is another type of tall forest, Valley forest, in which characteristic trees (all growing to about 40 m) are Apuleia molaris, Copaifera langsdorfii, Hymenaea stilbocarpa and Ormosia sp. (Tento). Much the most extensive type of Evergreen Seasonal forest is the Dry forest which represents the southern fringe of the Amazonian forest and covers a vast area stretching away northwards from the base camp area. This is a mixed community in which the trees seldom grow to more than 20 m. The most abundant species of the upper storey in the area studied are Chaetocarpus echinocarpus, Licania blackii, L. kunthiana, Sacoglottis guianensis and Xylopia amazonica. The transition from Dry forest to cerrado is sometimes abrupt, but elsewhere there is an ecotone in which Hirtella glandulosa cerradao forms a recognizable nodum, occupying a zone up to 4 km wide. Characteristic species in this are Emmotum nitens, Sclerolobium paniculatum and Vochysia haenkeana, as well as H. glandulosa. The boundary between cerrado and Dry forest appears to be dynamic and there are some indications that the forest has recently invaded the cerrado. The present boundary does not seem to be primarily dependent on climate or burning but shows some relation to soil conditions, though apart from a higher clay content in the latter the cerrado and forest soils are much alike. Cerrado has a lower degree of crown cover than cerradao; it is a type of open savanna with grassy undergrowth and is extremely variable in floristic composition and no clearly defined associations could be recognized. The boundary between cerrado and campo in valleys is sharp and appears to be determined by the height of the water table in the wet season. The mesotrophic soils are occupied by Deciduous Seasonal forest, the only woody community in the area in which the top storey becomes leafless in the dry season. The floristic composition of this community is very different from that of the other forest types and characteristic top-storey species include Cedrela fissilis, Piptadenia macrocarpa, Platypodium elegans and Sterculia striata, with Acacia polyphylla and Bauhinia cupulata as a second storey. Bamboos and the palm Acrocomia sp. are features of the under-growth. Floristically this community is similar to forest types found on calcareous rocks in Goias and Minas Gerais. It is fringed by a characteristic cerradao, termed Magonia pubescens/Callisthene fasciculata cerradao.

179 citations

Journal ArticleDOI
TL;DR: This paper describes the main structural and floristic characteristics of the plot in the Western Ghats of India and shows that two kinds of mature phases can be identified: where the topography is raised and gently sloping, the vertical structure of the stand is discontinuous, with Dipterocarpus indicus and Vateria indica forming an emergent layer above a dense undergrowth.
Abstract: A permanent plot of 28 ha was established in a dense wvet evergreen forest in the Western Ghats of India to study the functioning of the ecosystem. Since April 1990, 1981 trees of B30 cm gbh have been enumerated in a systematic sampling of five strips totalling 3.12 ha. This paper describes the main structural and floristic characteristics of the plot. The density (635 trees B30 cm gbh per hectare) and basal area (39.7 m2 ha-') are high. Despite the high diversity (Simpson's D = 0.92 and Shannon's H' = 4.56), four species are distinctly dominant in terms of an importance value index (relative density + relative basal area). Each of these four species occupies a different layer in the ecosystem: Hurinboldtia br-unonis Wall. (Fabaceae) dominates the undergiowth, Allyristica dactyloides Gaertn. (Myristicaceae) the inteirm-ediate strata, Vater-ia indica L. (Dipterocarpaceae) the higher canopy level and DiWterocaipis inidicius Bedd. (Dipterocarpaceae) the emergents. This pronounced species hierarchy is one of the most important characteristics of the evergreen forests of the Western Ghats. The two dipterocarps account for 20.1% of the total number of trees and contribute 40.9% to the total basal area. This formation can, therefore, be considered as the westernmost lowland dipterocarp forest of Asia. Analysis of the spatial variations in the floristic composition and in the structure of the main species populations shows that two kinds of mature phases can be identified: where the topography is raised and gently sloping, the vertical structure of the stand is discontinuous, with Dipterocaipus itidicuts and Vateria inidica forming an emergent layer above a dense undergrowth; on slopes, the stand is lower, vertically continuous and saturated with Vateria indica an-d Mvristica dactvloides. The link between the structure of the stand and dynamic processes is discussed.

164 citations

Journal ArticleDOI
TL;DR: Suggested improvements of current forest management and logging techniques for the maintenance of a higher proportion of the original biodiversity include minimizing logging damages, long rotations between cuts, and keeping unlogged forest patches within logging concessions.
Abstract: The composition and structure of bird communities, and the damage to forest structure were surveyed in northern French Guiana (northeastern Amazonia) one year and ten years after selective logging and compared with the situation in a similar undisturbed primary forest. A point-count method was used in which 937 0.25ha sample plots were censused for 20 minutes each, and their vegetation structure was measured. On average, 38% of the forest undergrowth was destroyed, then invaded by dense regrowth, and up to 63% of the canopy was substantially opened as a result of selective logging. Hunting pressure also increased due to access roads opened for logging. Among the 256 species recorded, overall bird species richness and abundance were depressed by 27–34% in the logged areas compared to primary forest. The most vulnerable guilds, which decreased by 37–98% in abundance, were mature forest understorey species, especially terrestrial ones and mixed flocks of insectivores. Hummingbirds, small gaps, vine tangles and canopy species did not decrease, nor increase significantly after logging. Only species naturally associated with dense second growth, forest edges and large gaps actually increased. Habitat specialization was the major determinant of vulnerability to logging, and, to a lesser degree, size (large) and diet (insectivorous), but foraging behaviour and rarity had little effect. Bird sensitivity to changes in logged forest structure may involve physiological intolerance, reduced food categories, increased exposure to predators, too dense understorey for their specific foraging behaviour and/or avoidance of gaps. Suggested improvements of current forest management and logging techniques for the maintenance of a higher proportion of the original biodiversity include minimizing logging damages, long rotations (>50 years) between cuts, and keeping unlogged forest patches within logging concessions.

162 citations

Journal ArticleDOI
TL;DR: In this article, geometrid moths were collected on Mt. Kinabalu (Sabah, Malaysia) along two habitat gradients, ranging from primary rain forest to cultivated areas.
Abstract: Geometrid moths were collected on Mt. Kinabalu (Sabah, Malaysia) along two habitat gradients, ranging from primary rain forest to cultivated areas. During 135 nights' trapping in 1997, 4585 individuals representing 500 species were attracted by light. Primary forest samples and those from old-grown regenerated forest exhibited high diversity (Fisher's α = 75–128), while agricultural areas as well as most secondary forests had a significantly lower diversity (α = 34–61). One 15-y-old secondary forest with a rich undergrowth vegetation also housed a diverse geometrid community (α = 89). In three paired samples, diversity of geometrid moths in the canopy was equal to or lower than in the understorey. Of six habitat variables tested, only undergrowth plant species diversity emerged as a significant predictor of geometrid diversity. The NESS index, in combination with multi-dimensional scaling, was used to investigate patterns of between-habitat diversity. Of two dimensions extracted, one represented the degree of habitat disturbance, while the other separated the two study areas. Geometrid samples of strongly disturbed habitats did not converge between sites, indicating that apart from the degree of human interference the regional species pool was also important in determining similarity among local communities.

160 citations


Network Information
Related Topics (5)
Forest management
25.8K papers, 587.6K citations
74% related
Plant litter
10.2K papers, 401.8K citations
74% related
Forest ecology
18.7K papers, 618.7K citations
73% related
Canopy
15.1K papers, 472.3K citations
72% related
Soil biodiversity
10K papers, 337.5K citations
71% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202337
202293
202133
202030
201934
201836