Spectral reflectance of multispecies herbaceous and moss canopies in the boreal forest understory and open field

2009 ◽  
Vol 35 (5) ◽  
pp. 474-485 ◽  
Author(s):  
Lea Hallik ◽  
Olevi Kull ◽  
Tiit Nilson ◽  
Josep Peñuelas
Keyword(s):  
Boreal Forest ◽  
Open Field ◽  
Spectral Reflectance ◽  
Forest Understory

Nitrogen-addition effects on leaf traits and photosynthetic carbon gain of boreal forest understory shrubs

Oecologia ◽  
2014 ◽  
Vol 175 (2) ◽  
pp. 457-470 ◽  
Author(s):  
Sari Palmroth ◽  
Lisbet Holm Bach ◽  
Annika Nordin ◽  
Kristin Palmqvist
Keyword(s):  
Boreal Forest ◽  
Leaf Traits ◽  
Nitrogen Addition ◽  
Forest Understory ◽  
Carbon Gain ◽  
Photosynthetic Carbon ◽  
Understory Shrubs

Physiological competitiveness of autumn olive compared with native woody competitors in open field and forest understory

2016 ◽  
Vol 372 ◽  
pp. 101-108 ◽  
Author(s):  
David L. Dornbos ◽  
Michele R. Martzke ◽  
Kelly Gries ◽  
Rachel Hesselink
Keyword(s):  
Open Field ◽  
Forest Understory ◽  
Autumn Olive

Density dependence in an experimental boreal forest understory community

Botany ◽  
2010 ◽  
Vol 88 (8) ◽  
pp. 753-764 ◽  
Author(s):  
Michael A. Treberg ◽  
Roy Turkington
Keyword(s):  
Boreal Forest ◽  
Density Dependence ◽  
Abiotic Factors ◽  
Life Stage ◽  
Plant Competition ◽  
Biotic Interactions ◽  
Abundant Species ◽  
Forest Understory ◽  
Density Dependent ◽  
Shoot Mass

Density-dependent regulation in plants may occur at the level of the entire community and may differ in magnitude and direction at different life history stages such as germination, survival and growth, and under different abiotic conditions. We constructed semi-natural communities of boreal forest understory species planting 10 of the most abundant species. The experimental communities were established from seed or from cuttings and grown in sandboxes at six densities that extended far above and below average natural field density, while maintaining constant relative species proportions (a community density series (CDS)). We used two watering and fertilization levels in a factorial design. At the community level, both emergence and final per-plant shoot mass were negatively density dependent, while survival to the end of the season was facilitative. The effect of water was positive at seed emergence, whereas fertilizer negatively affected survival. Species-specific responses were also dependent on life stage. We demonstrated that density dependence is important in structuring this unproductive boreal understory habitat. The CDS approach allows us to quantify the effects of plant competition at the community and species levels, and to determine whether the importance of these biotic interactions depend on abiotic factors.

scholarly journals Topography modulates near-ground microclimate in the Mediterranean Fagus sylvatica treeline

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Angelo Rita ◽  
Giuliano Bonanomi ◽  
Emilia Allevato ◽  
Marco Borghetti ◽  
Gaspare Cesarano ◽  
...  
Keyword(s):  
Climate Change ◽  
Open Field ◽  
Forest Understory ◽  
Maximum Temperature ◽  
The South ◽  
Ecological Fitness ◽  
Free Air ◽  
Field Temperature ◽  
Local Topography ◽  
Microclimatic Conditions

AbstractUnderstanding processes controlling forest dynamics has become particularly important in the context of ongoing climate change, which is altering the ecological fitness and resilience of species worldwide. However, whether forest communities would be threatened by projected macroclimate change or unaffected due to the controlling effect of local site conditions is still a matter for debate. After all, forest canopy buffer climate extremes and promote microclimatic conditions, which matters for functional plant response, and act as refugia for understory species in a changing climate. Yet precisely how microclimatic conditions change in response to climate warming will depend on the extent to which vegetation structure and local topography shape air and soil temperature. In this study, we posited that forest microclimatic buffering is sensitive to local topographic conditions and canopy cover, and using meteorological stations equipped with data-loggers we measured this effect during 1 year across a climate gradient (considering aspect as a surrogate of local topography) in a Mediterranean beech treeline growing in contrasting aspects in southern Italy. During the growing season, the below-canopy near-ground temperatures were, on average, 2.4 and 1.0 °C cooler than open-field temperatures for south and north-west aspects, respectively. Overall, the temperature offset became more negative (that is, lower under-canopy temperatures at the treeline) as the open-field temperature increased, and more positive (that is, higher under-canopy temperatures at the treeline) as the open-field temperature decreased. The buffering effect was particularly evident for the treeline on the south-facing slope, where cooling of near-ground temperature was as high as 8.6 °C for the maximum temperature (in August the offset peaked at 10 °C) and as high as 2.5 °C for the average temperature. In addition, compared to the south-facing slope, the northern site exhibited less decoupling from free-air environment conditions and low variability in microclimate trends that closely track the free-air biophysical environment. Although such a decoupling effect cannot wholly isolate forest climatic conditions from macroclimate regional variability in the south-facing treeline, it has the potential to partly offset the regional macroclimatic warming experienced in the forest understory due to anthropogenic climate change.

Contrasting responses of lichens and Vaccinium angustifolium to long-term acidification of a boreal forest ecosystem

1989 ◽  
Vol 67 (2) ◽  
pp. 579-588 ◽  
Author(s):  
Martha G. Scott ◽  
Thomas C. Hutchinson ◽  
Marilyn J. Feth
Keyword(s):  
Boreal Forest ◽  
Growth Parameters ◽  
Light Attenuation ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Forest Understory ◽  
Permanent Plots ◽  
Percent Cover ◽  
Vaccinium Angustifolium ◽  
Understory Species

Over a 5-year period, we investigated the effects of simulated acidic precipitation on boreal forest understory species. Percent cover, net photosynthetic rate, and growth of three species of subarctic lichens were evaluated. Throughout the growing season, Cladina stellaris, Cladina rangiferina, and Cladina mitis, along with the associated vascular perennial, Vaccinium angustifolium, received twice-monthly sprays of artificial rain adjusted to pH 5.6, 4.0, 3.5, 3.0, or 2.5 using a 2:1 ratio of sulfuric to nitric acids. Changes in percent cover of the flora in permanent plots were measured annually during treatment years and then for a 6th year to monitor postspray recovery. Following 5 years of spraying, combined cover values for the three lichen species had decreased by up to 27% in plots sprayed with rain of less than pH 4.0, while percent cover of V. angustifolium had increased by 55 %. Although losses in net photosynthesis of 65% occurred for lichens receiving rains of pH 2.5, differences were not significant and data were highly variable. However, increasing acidity of the sprays significantly suppressed mean podetial height and dry weight of C. stellaris and C. mitis. The effect on these lichens of shading by the potential competitor V. angustifolium was investigated in a companion study, and it was concluded that the growth suppression of C. stellaris was most likely related to rainfall acidity and not to light attenuation. Cladina mitis was more sensitive to low light levels. Although adversely affected by rain of pH 2.5, C. rangiferina showed stimulation of a number of growth parameters in plots sprayed with rain of pH 3.0. It was concluded that responses of boreal understory species are variable and complex, and that several species (i.e., C. rangiferina and V. angustifolium) are tolerant of rainfall of less than pH 3.5.

scholarly journals Mechanisms for Success after Long-term Nutrient Enrichment in a Boreal Forest Understory

PLoS ONE ◽  
2013 ◽  
Vol 8 (4) ◽  
pp. e61229 ◽  
Author(s):  
Tess Nahanni Grainger ◽  
Roy Turkington
Keyword(s):  
Boreal Forest ◽  
Nutrient Enrichment ◽  
Forest Understory

scholarly journals Turnover in boreal forest understory following disturbance varies along a fertility gradient

Authorea ◽  
2020 ◽  
Author(s):  
Elina Kaarlej rvi ◽  
Maija Salemaa ◽  
Tiina Tonteri ◽  
P ivi Meril ◽  
Anna Liisa Laine
Keyword(s):  
Boreal Forest ◽  
Forest Understory ◽  
Fertility Gradient
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