Light attenuation by early successional plants of the boreal forest

2001 ◽  
Vol 31 (5) ◽  
pp. 812-823 ◽  
Author(s):  
Christy Shropshire ◽  
Robert G Wagner ◽  
F Wayne Bell ◽  
Clarence J Swanton

The influence of eight early successional plant species from the boreal forest on photosynthetically active radiation (PAR) were compared using a controlled plant competition study. Four woody (green alder, Alnus crispa (Ait.) Pursh; upland willow, Salix humilis Marsh.; white birch, Betula papyrifera Marsh.; wild red raspberry, Rubus idaeus L.) and four herbaceous (eastern bracken fern, Pteridium aquilinum L.; bluejoint grass, Calamagrostis canadensis Michx.; large-leaved aster, Aster macrophyllus L.; fireweed, Epilobium angustifolium L.) plant species were studied using an additive density experiment with jack pine (Pinus banksiana Lamb.) seedlings. The transmission of PAR through the plant canopies was measured using a line quantum sensor under six plant density treatments at the time of maximum canopy development each year. Four measures of plant abundance (planting density, actual density, projected leaf area index, and crown cover) were evaluated for their ability to predict PAR transmission through the plant canopies. Visual estimates of crown cover provided the best models each year. Vertical profiles of PAR transmission were used to compare the canopy structure among plant species and were used to refine the models. During the second growing season, increasing crown cover of bluejoint grass and large-leaved aster had the largest influence on PAR. In the third season, green alder, upland willow, and white birch (along with bluejoint grass and fireweed at the jack pine crown level) had the greatest influence on PAR. PAR measurements taken from a nearby forest for several of the plant species indicate that the models developed from our controlled experiment are reasonably applicable to naturally occurring plant populations.

2001 ◽  
Vol 79 (9) ◽  
pp. 1019-1027 ◽  
Author(s):  
Sonia Légaré ◽  
Yves Bergeron ◽  
Alain Leduc ◽  
David Paré

Variation in canopy composition can influence ecosystem processes, such as nutrient cycling and light transmittance, even when environmental soil conditions are similar. To determine whether forest cover type influences species composition of the understory vegetation (herbs and shrubs), the composition of this layer was studied on two different surface deposits, clay and till, and under four different forest cover types dominated, respectively, by Populus tremuloïdes Michx. (aspen), Betula papyrifera Marsh. (white birch), Pinus banksiana Lamb. (jack pine), and Picea glauca (Moench) Voss – Abies balsamea (L.) Mill. (spruce–fir) over similar environmental conditions. Detrended correspondence analysis and analysis of variance performed on the ordination scores revealed that understory plant composition was highly affected by surface deposit and forest cover. The gradient observed in the correspondence analysis proceeds from aspen, white birch, spruce–fir, to jack pine. Indicator species were identified for each surface deposit and cover type, and most of them were associated with either jack pine or aspen. The richness, evenness, and diversity of the understory vegetation did not vary between cover types, but were affected by surface deposit. By controlling ecosystem processes such as light transmittance and nutrient cycling, forest cover influences understory composition.Key words: cover, understory, composition, boreal forest, environmental condition.


2008 ◽  
Vol 42 (16) ◽  
pp. 5911-5916 ◽  
Author(s):  
Luca Nizzetto ◽  
Cristina Pastore ◽  
Xiang Liu ◽  
Paolo Camporini ◽  
Daniela Stroppiana ◽  
...  

1983 ◽  
Vol 63 (2) ◽  
pp. 363-375 ◽  
Author(s):  
R. M. DANIELSON ◽  
S. VISSER ◽  
D. PARKINSON

Slender wheatgrass and jack pine were grown in the greenhouse in cores containing a bottom layer of extracted oil sands with four overburdens individually layered over the sand. The overburdens included a muskeg peat, two shallow mineral overburdens and a deep overburden. Mycorrhizal development, microbial respiration and biomass and the degree of decomposition of slender wheatgrass roots in litter bags were determined in each plant species-overburden combination. Both ecto- and vesicular-arbuscular (VA) mycorrhizal inoculum was present in all four overburdens. The symbionts of slender wheatgrass were the "fine endophyte" and Glomus aggregatum. VA development was very low in peat whereas plants in the shallow overburdens became heavily mycorrhizal. Infection did not spread from the overburden layer to roots in the tailing sand. Jack pine roots in the peat and two shallow overburdens were heavily infected after 4 months. The most common symbiont was an ascomycete known as the E-strain. Microbial respiration was highest in the peat and was not influenced by plant species. Microbial biomass was also highest in the peat and much lower in the mineral overburdens. Only in the peat was the amount of microbial biomass larger with slender wheatgrass than with jack pine. Slender wheatgrass roots decomposed most rapidly in the peat overburden and least rapidly in the deep overburden. Key words: Microbial activity, jack pine, slender wheatgrass, mycorrhizae, reclamation, oil sands


Author(s):  
Terhikki Manninen ◽  
Jean‐Louis Roujean ◽  
Olivier Hautecoeur ◽  
Aku Riihelä ◽  
Panu Lahtinen ◽  
...  

2017 ◽  
Vol 420 (1-2) ◽  
pp. 195-208 ◽  
Author(s):  
Monica Calvo-Polanco ◽  
Wenqing Zhang ◽  
S. Ellen Macdonald ◽  
Jorge Señorans ◽  
Janusz J. Zwiazek

1972 ◽  
Vol 48 (1) ◽  
pp. 30-31
Author(s):  
C. W. Yeatman ◽  
M. J. Holst
Keyword(s):  

not available


2017 ◽  
Vol 4 (1) ◽  
pp. 148-160
Author(s):  
Arjun C.P ◽  
Anoop V.K ◽  
Tijo K.J ◽  
Anoopkumar T.K ◽  
Roshnath R

Butterfly diversity was recorded from Nov (2013) - May (2014) in Pookode region. A total number of 128 species recorded from the five families; Nymphalidae (46 species) Lycaenidae (28 species), Hesperiidae (22 species), Pieridae (17 species) and Papilionidae (15 species) respectively. During the survey invasive plant species were also recorded. There were 36 species of invasive plants from 18 families identified from the study area. More butterflies were attracted towards nectar offering invasive plants. Chromolaena odorata, Ipomea cairica, Lantana camara, Merremia vitifolia, Mikania micrantha, Mimosa diplotricha, Pennisetumpolystachyon, Pteridium aquilinum, Quisqualis indica and Sphagneticola trilobata were the major invasive plants found in the Pookode region and their flower attracts butterfly for pollination. Even though nectar offered by the plants are supportive for growth, in long run these species can affect butterfly population bydeclining native host larval plant species for butterfly reproduction. Invasive species compete with the native flora and reduce its population. Management practices like physical, chemical and modern bio control measures could be used for eradicating of invasive plants. Wise use of invasive plants for other economical purpose such as bio-fuel, medicinal purpose, bio-pesticide and handicraft could be suggested. Successful management of invasive species are needed for conserving Lepidoptera fauna and other native biota of the area.


Author(s):  
Santonu Goswami ◽  
John Gamon ◽  
Sergio Vargas ◽  
Craig Tweedie

Here we investigate relationships between NDVI, Biomass, and Leaf Area Index (LAI) for six key plant species near Barrow, Alaska. We explore how key plant species differ in biomass, leaf area index (LAI) and how can vegetation spectral indices be used to estimate biomass and LAI for key plant species. A vegetation index (VI) or a spectral vegetation index (SVI) is a quantitative predictor of plant biomass or vegetative vigor, usually formed from combinations of several spectral bands, whose values are added, divided, or multiplied in order to yield a single value that indicates the amount or vigor of vegetation. For six key plant species, NDVI was strongly correlated with biomass (R2 = 0.83) and LAI (R2 = 0.70) but showed evidence of saturation above a biomass of 100 g/m2 and an LAI of 2 m2/m2. Extrapolation of a biomass-plant cover model to a multi-decadal time series of plant cover observations suggested that Carex aquatilis and Eriophorum angustifolium decreased in biomass while Arctophila fulva and Dupontia fisheri increased 1972-2008.


Author(s):  
Ellen Eigemeier ◽  
Janne Heiskanen ◽  
Miina Rautiainen ◽  
Matti Mttus ◽  
Veli-Heikki Vesanto ◽  
...  

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