Plants understory

Harward, M., and M. Treshow. Impact of ozone on the growth and reproduction of understory plants in the aspen zone of western U.S.A. Environ. Conserv. 2 17-23, 1975. 

Harward, M. R. The Impact of Ozone on the Understory Plants of the Aspen Zone. Ph.D. Hiesis. Salt Lake City University of Utah, 1971. 104 pp. 

The dart-poison frog Dendrobatespumilio uses odors for homing. This species lives in the understory of lowland tropical forests in Central America. The eggs are laid on land, and the female carries the newly hatched tadpoles on her back to water-filled leaf axils of bromeliads. She feeds the tadpoles with unfertilized eggs, while the male defends the territory. Captive dart-poison frogs tested in a Y-olfactometer chose the odor from their own communal tank over odors from tanks planted with different plants. However, they did not distinguish between... 

Vegetation under the trees in Japanese red pine, Pinus densiflora, forests is sparse despite the fact that the interior of these forests is one of the brightest among forests (22,23). Many other forests have dense undergrowths of herbs in spite of much lower light intensities. Various parts of red pine and the soil under it contained chemicals toxic to many potential understory plants. Thus, it was concluded that allelopathy probably plays an important role in retarding understory growth. 

Several authors have obtained circumstantial evidence that allelopathic compounds reduce mycorrhizae formation (20-23). Kovacic and associates ( ) have shown that understory plants in a live ponderosa pine stand are largely nonmycorrhiza-forming species. They hypothesized that this was due to inhibition of the vesicular-arbuscular mycorrhiza necessary for the growth of herbaceous mycorrhizal plants, under living pines. They demonstrated that more mycorrhizal plants occurred under dead pines, bioassay plants formed mycorrhizae in soils beneath dead pines but not in soil beneath live pines, and mycorrhizal inoculum appeared to be absent from the live pine stand. 

Hollis and associates (TD investigated the allelopathic effect of nine of the most abundant herbaceous and shrubby understory associates in Lower Coastal Plain flatwoods pine stands on germination, radicle extension, and shoot growth of slash and loblolly pine. They identified lyonia (Lyonia lucida) as a strong inhibitor of both pine species. Subsequent field studies confirmed that lyonia reduced the growth of planted slash pine. Few studies have followed lab or greenhouse results with corroboration from field studies. Fewer yet have adequately traced the path of allelochemicals in the environment. 

Some plants experience a short-lived abundance of nitrogen. Most annuals occupy disturbed or semi-disturbed habitats which are characterized by a sudden release of nutrients (25). Even many herbaceous perennials occur under seml-dlsturbed conditions (eg. old fields), or grow during a short Interval between climatic limitations and biotic competition when resources are relatively abundant, as Is the case of the forest understory flora (26, 27). 

Harward and Treshow (24) have suggested that ozone could completely remove the most sensitive understory plants in the aspen zone in Utah it is likely that sensitive species may have already been eliminated from the heavily damaged mixed conifer forest of our study site. 

In the past, reforestation relied on the establishment of monospecific plantations, often with exotics (e.g.. Eucalyptus, Pinus, Acacia spp.) or a limited number of native tree taxa for which seeds are readily available and silvicultural practices have been developed (Knowles and Parrotta 1995). Also at Porto Trombetas, about 160 native forest species in mixed plantings were evaluated for their suitability for forest restoration on bauxite mine land over a 14-year period. Observations over 600 ha of plantings have yielded information on ecological characteristics of the species and cost-effective propagation methods. The plantations of exotics and natives are expected to catalyze natural forest succession in the understory and thus accelerate the rate at which species-rich native forest stands develop on severely degraded lands. 

Forest biomass in the Amazon has been estimated through direct and indirect methods. Independent of the method used, one should take into consideration that all components of forest biomass must be quantified. Besides the trees that are the main component of the forest, other components to be included are vines Gianas), understory plants, litter, roots, palms, etc. 

Some components of NPP, such as root production, are particularly difficult to measure and have sometimes been assumed to be some constant ratio (e.g., 1 1) of aboveground production (Fahey et al., 1998). Fewer than 10% of the studies that report total ecosystem NPP actually measure components of belowground production (Clark et al., 2001). Estimates of aboveground NPP sometimes include only large plants (e.g., trees in forests) and exclude understory shrubs or mosses, which can account for a... 

Chazdon R. L. and Pearcy R. W. (1991) The importance of sunflecks for forest understory plants. Bioscience 41, 760-766. 

Pearcy R. W. (1988) Photosynthetic utilisation of lightflecks by understory plants. Austral. J. Plant Physiol. 15, 223-238. 

When you re purchasing the fresh produce, you will typically find two blueberry sizes, representing two distinct but related species the smaller, pea-size, low-bush variety, which was cultivated from original wild plants of Atlantic Canada and northern forest understories and the grape-size, American highbush species, which was developed specifically to yield larger fruit on taller bushes, making the crop easier to pick with mechanical harvesters. 

Adams WW III, Demmig-Adams B, Logan BA, Barker DH and Osmond CB (1999) Rapid changes in xanthophyll cycle-dependent energy dissipation and Photosystem II efficiency in two vines, Stephania japonica and Smilax australis, growing in the understory of an open Eucalyptus forest. Plant Cell Environ 22 125-136... 

KonigerM, Harris GC, Virgo A and Winter K( 1995) Xanthophyll-cycle pigments and photosynthetic capacity in tropical forest species A comparative field study on canopy, gap and understory plants. Oecologia 104 280-290 Laemmli UK (1970) Cleavage of structural proteins during assembly of the head of bacteriophage T4. Nature 227 680-685... 

Wiirth, M. K. R., Winter, K., and Korner, C. (1998). In situ responses to elevated CO2 in tropical forest understory plants. Functional Ecol. 12, 886-895. 

Berry, S. C., Vtirney, G. T., and Flanagan, I.. B. (1997). Leaf d C in Piinis resinosa trees and understory plants Variation associated with light and CO, gradients. Oecologia (Berlin) 109,499-506. 

By 1970, in the wake of efforts to capitalize on the newly realized medicinal value of podophyllotoxin for Western medicine, more than 130 tons of Podophyllum rhizomes were needed in the US annually to satisfy the demand for the compound [6]. This plant material was wild-harvested from the understory of oak and hickory forests of the eastern and central US. In 1974, mayapple was considered a common plant with a natural habitat extending from South Carolina to Maine along the Atlantic coast in the East, to eastern Texas, Oklahoma, and Kansas beyond the Mississippi basin in the West, and as far North as Lake Michigan [6]. Today, mayapple is commonly seen along roadsides and can still be abundantly found in other readily accessible areas within its natural range. Several... 

Coffee grows naturally In the understory of the wet tropical forest and bears some physiological characteristics of a shade plant (1). Air humidity is certainly an important factor in the devellopment of the plant,but the basic information on this topic is very short. In sequence of previous work ( 2) this, presents more data showing that low air humidity is a stress factor on photosynthesis and suggests that it affects not only stomatal conductance but chemical characteristics of the mesophyll related with photosynthesis. 

Three common subalpine species were selected Mahonia repens, Rumex densiflorus and Populus tremuloides. Mahonia repens is a low stature understory shrub with horizontal foliage. Rumex densiflorus and Populus tremuloides, an open-growing herb and tree, respectively, have primarily vertical leaf orientation. Plants grew in an Artemisia-dominated forest opening and in the adjacent understory of a dense stand of Pinus contorta at ca. 300 m in the Medicine Bow Mountains, Wyoming. The forest opening and understory were selected... 

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