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 published on a yearly basis
Papers
More filters
•
21 citations
••
TL;DR: Evaluating the long–term impacts of herbivore, fire and termite activities on regeneration of trees in Burkina Faso found grazed quadrats had significantly increased species richness and stem density between burnt and unburnt quadrats.
21 citations
••
TL;DR: A threshold method adapted for this lidar was used to accurately extract from its waveforms detailed forest canopy vertical structure: canopy top, tree crown base and undergrowth heights, and statistical and one-to-one comparisons with ground measurements by field foresters indicated a mean absolute accuracy of 1 m.
Abstract: We have developed a new airborne UV lidar for the forest canopy and deployed it in the Landes forest (France). It is the first one that: (i) operates at 355 nm for emitting energetic pulses of 16 mJ at 20 Hz while fulfilling eye-safety regulations and (ii) is flown onboard an ultra-light airplane for enhanced flight flexibility. Laser footprints at ground level were 2.4 m wide for a flying altitude of 300 m. Three test areas of ~500 × 500 m2 with Maritime pines of different ages were investigated. We used a threshold method adapted for this lidar to accurately extract from its waveforms detailed forest canopy vertical structure: canopy top, tree crown base and undergrowth heights. Good detection sensitivity enabled the observation of ground returns underneath the trees. Statistical and one-to-one comparisons with ground measurements by field foresters indicated a mean absolute accuracy of ~1 m. Sensitivity tests on detection threshold showed the importance of signal to noise ratio and footprint size for a proper detection of the canopy vertical structure. This UV-lidar is intended for future innovative applications of simultaneous observation of forest canopy, laser-induced vegetation fluorescence and atmospheric aerosols.
21 citations
••
TL;DR: Growth strategies of six species of trees are compared and used to analyze forest architecture and Fagus grandifolia is predicted to become the main dominant species, but the frequent hurricanes open the forest canopy and provide opportunities for understory species and light-demanding overstory species.
Abstract: Growth strategies of six species of trees are compared and used to analyze forest architecture. They included the overstory speciesFagus grandifolia, Magnolia grandiflora, Pinus glabra andLiquidambar styraciflua, and the understory speciesOstrya virginiana andIlex opaca. The six species were abundant in Woodyard Hammock, an old-growth forest in northern Florida, USA. Height, stem diameter, crown projection and radial growth were measured in trees between 5 and 35 m tall. Three different, but non-exclusive, growth strategies were identified for the tree species: ‘survival’ (Fagus grandifolia, Magnolia grandiflora, Ilex opaca), ‘occupy open space’ (Fagus grandifolia, Ostrya virginiana, Ilex opaca), and ‘reach above competitors’ (Liquidambar styraciflua, Pinus glabra). In two transects (0.42 ha) and one quadrat (1 ha), heights of dominant trees were used to distinguish different phases of forest development, which were mapped. In the quadrat, juvenile canopy trees in the undergrowth were mapped. The combination of presence of different developmental phases, presence of juveniles in the undergrowth, growth strategies of main tree species, and disturbance regime was used to assess forest development in the near future.Fagus grandifolia is predicted to become the main dominant species, but the frequent hurricanes open the forest canopy and provide opportunities for understory species (Ostrya virginiana andIlex opaca), and light-demanding overstory species (Liquidambar styraciflua andPinus glabra).
20 citations
••
TL;DR: In this paper, the characteristics of soil nutrient elements and the changes in biomass under different densities and soil layers of forest stand were studied in Naxi District, Sichuan Province, China.
Abstract: In order to study the characteristics of soil nutrient elements and the changes in biomass under different densities and soil layers of forest stand, this paper considers Chinese fir (Cunninghamia lanceolata (Lamb.) Hook) density test forests with five densities (A: 1667 trees·ha−1; B: 3333 trees·ha−1; C: 5000 trees·ha−1; D: 6667 trees·ha−1; E: 10,000 trees·ha−1) as the research objects, located in Naxi District, Sichuan Province, China. Eleven soil physical and chemical property indicators, understory vegetation, and litter biomass were measured. The results were as follows: (1) The stand density had a significant effect on the soil nutrient content, understory vegetation, and litter biomass. A low density is conducive to the accumulation of soil organic matter, hydrolytic N, available P, available K, and total Ca. (2) With the increase in soil depth, the contents of soil organic matter, total N, hydrolytic N, and total P decreased gradually; pH and total Ca decreased gradually; and available P showed a trend of decrease-up-decrease. The soil layers had no significant effect on the total K, total Fe, and total Mg concentrations. (3) Low density (density A or B) was found to be beneficial to the growth of undergrowth vegetation and forest trees, the return of nutrients, long-term soil maintenance, and the stable high yield of Chinese fir plantations.
20 citations