Response of aboveground biomass increment, growth efficiency, and foliar nutrients to thinning, fertilization, and pruning in young Douglas-fir plantations in the central Oregon Cascades

1992 ◽  
Vol 22 (9) ◽  
pp. 1278-1289 ◽  
Author(s):  
Alejandro Velazquez-Martinez ◽  
David A. Perry ◽  
Tom E. Bell
Keyword(s):  
Leaf Area ◽  
Aboveground Biomass ◽  
Cultural Practices ◽  
Growth Efficiency ◽  
Douglas Fir ◽  
Nitrogen And Phosphorus ◽  
Area Index ◽  
Biomass Increment ◽  
Oregon Cascades

The effect of thinning and cultural practices (multinutrient fertilization, pruning) on total aboveground biomass increment and growth efficiency was studied over three consecutive 2-year periods (1981–1987) in young Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) plantations. Net aboveground biomass increment over the 6-year period averaged 14.5, 7.8, and 5.5 Mg•ha−1•year−1 for the high-, medium-, and low-density plots, respectively. Growth efficiency, after dropping sharply between leaf area indexes of 1 and 6 m2/m2, remained relatively constant up to a leaf area index of 17, the highest measured. Consequently, aboveground biomass increment continued to increase at leaf area indexes well above that at which the Beer–Lambert law predicts maximum light should be absorbed. Foliage analyses indicate that thinning improved nitrogen, potassium, and magnesium nutrition and increased the translocation of potassium from 1-year-old foliage to support new growth. However, fertilization increased foliar nitrogen and phosphorus contents only when coupled with pruning, suggesting that trees favor total leaf area over individual needle nutrition. Indications of potassium and magnesium limitations in this study are supported by other recent studies in Douglas-fir. Further work on the role of multinutrient deficiencies in this species is warranted.

Distribution and increment of biomass in adjacent young Douglas-fir stands with different early growth rates

1987 ◽  
Vol 17 (7) ◽  
pp. 722-730 ◽  
Author(s):  
Miguel A. Espinosa Bancalari ◽  
David A. Perry
Keyword(s):  
Growth Rates ◽  
Aboveground Biomass ◽  
Early Growth ◽  
Douglas Fir ◽  
Rooting Depth ◽  
Summer Drought ◽  
Total Biomass ◽  
Area Index ◽  
Biomass Increment ◽  
Anaerobic Soils

Total biomass increments were determined for three adjacent 22-year-old Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) plantations in the Oregon Coast Range that had widely different early growth rates. Estimated total aboveground biomass of the stands, designated slow, intermediate, and fast, was 98.7, 148.7, and 203.7 Mg•ha−1, respectively; estimated mean biomass increment in the 5 years previous to sampling was 8.9, 12.6, and 12.3 Mg•ha−1•year−1. The slow stand had a greater proportion of aboveground biomass in branches and a smaller proportion in stem wood than the intermediate and fast stands. Differences in biomass increment were primarily due to stem rather than crown growth. Total below ground biomass was highest in the fast stand, the difference being due to roots >5 mm in diameter; weight of roots <5 mm was greater in the slow and intermediate stands. Roots >5 mm comprised about 77% of the total root system in those stands and 90% in the fast stand. Increment of roots >5 mm was 2.2, 2.5, and 3.0 Mg•ha−1•year−1 in the slow, intermediate, and fast stands. The ratio of productivity to total leaf nitrogen suggests that nitrogen is a principal limiting resource in the intermediate stand. The fast stand, with a leaf area index 50% greater than the others, is probably limited by light. The slow stand has anaerobic soils during at least part of the year, which may restrict rooting depth and thereby induce water stress during summer drought.

Eight-year responses of light interception, effective leaf area index, and stemwood production in fertilized stands of interior Douglas-fir (Pseudotsuga menziesii var. glauca)

2000 ◽  
Vol 30 (5) ◽  
pp. 733-743 ◽  
Author(s):  
Nick J Balster ◽  
John D Marshall
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Pseudotsuga Menziesii ◽  
Growth Efficiency ◽  
Light Interception ◽  
Douglas Fir ◽  
Area Index ◽  
Volume Production ◽  
High Fertilization ◽  
Effective Leaf Area Index

Data from 72 Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco) plots across the Interior Northwest were used to determine whether (i) increased intercepted photosynthetically active radiation (%IPAR), effective leaf area index (LAIe), and stemwood volume production (cubic metres stemwood per hectare per year) could still be detected 7 or 8 years after nitrogen fertilization and (ii) fertilization would increase the efficiency by which light is converted into stemwood volume. Projected LAIe varied from 1.82 to 6.07 m2·m-2 on the control plots. The fertilized plots intercepted 9-11% more light than the control plots (P < 0.001); they also had 22-25% higher LAIe than the control plots (P < 0.001). Stemwood volume production increased by 25-29% relative to the control (P < 0.001) and increased exponentially with %IPAR across all study plots (R2 = 0.57). Stemwood growth efficiency averaged 12.0 ± 0.4 (mean ± SE), 13.5 ± 0.4, and 13.7 ± 0.4 m3·ha-1·a-1 per IPAR for the control, low fertilization, and high fertilization plots, respectively (P < 0.01). Fertilization thus induced increases in both light interception and the efficiency with which intercepted light was converted to stemwood across the region.

Comparison of Methods of Estimating Leaf-Area Index In Old-Growth Douglas-Fir

Ecology ◽  
1986 ◽  
Vol 67 (4) ◽  
pp. 975-979 ◽  
Author(s):  
J. D. Marshall ◽  
R. H. Waring
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Douglas Fir ◽  
Comparison Of Methods ◽  
Old Growth ◽  
Area Index

scholarly journals The effect of rainfall amount and timing on annual transpiration in a grazed savanna grassland

2021 ◽  
Author(s):  
Matti Räsänen ◽  
Mika Aurela ◽  
Ville Vakkari ◽  
Johan P. Beukes ◽  
Juha-Pekka Tuovinen ◽  
...  
Keyword(s):  
Leaf Area ◽  
Gross Primary Production ◽  
Co2 Exchange ◽  
Wet Season ◽  
Area Index ◽  
C4 Grass ◽  
Precipitation Timing ◽  
Dry Spells ◽  
Annual Water

Abstract. The role of precipitation (P) variability on evapotranspiration (ET) and its two components, transpiration (T) and evaporation (E) from savannas, continues to draw significant research interest given its relevance to a number of eco-hydrological applications. Our study reports on six years of measured ET and estimated T and E from a grazed savanna grassland in Welgegund, South Africa. Annual P varied significantly in amount (508 to 672 mm yr−1), with dry years characterized by infrequent early-season rainfall. T was determined using annual water-use efficiency and gross primary production estimates derived from eddy covariance measurements of latent heat flux and net ecosystem CO2 exchange rates. The computed annual T was nearly constant, 331 ± 11 mm yr−1 (T/ET = 0.52), for the four wet years with frequent early wet-season rainfall, whereas annual T was 268 and 175 mm yr−1 during the dry years. Annual T/ET was linearly related to the early wet-season storm frequency. The constancy of annual T during wet years is explained by the moderate water stress of C4 grass and constant annual tree transpiration covering 15 % of the landscape. However, grass transpiration declines during dry spells. Moreover, grasses respond to water availability with a dieback-regrowth pattern, reducing leaf area and transpiration during drought. These changes lead to an anomalous monthly T/ET relation to leaf-area index (LAI). The results highlight the role of the C4 grass layer in the hydrological balance and suggest that the grass response to dry spells and drought is reasonably described by precipitation timing.

scholarly journals Estimating leaf area index and aboveground biomass of grazing pastures using Sentinel-1, Sentinel-2 and Landsat images

2019 ◽  
Vol 154 ◽  
pp. 189-201 ◽  
Author(s):  
Jie Wang ◽  
Xiangming Xiao ◽  
Rajen Bajgain ◽  
Patrick Starks ◽  
Jean Steiner ◽  
...  
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Aboveground Biomass ◽  
Landsat Images ◽  
Area Index ◽  
Sentinel 2

Influence of Herbaceous Interference on Growth and Biomass Partitioning in Planted Loblolly Pine (Pinus taeda)

Weed Science ◽  
1990 ◽  
Vol 38 (6) ◽  
pp. 497-503 ◽  
Author(s):  
John R. Britt ◽  
Bruce R. Zutter ◽  
Robert J. Mitchell ◽  
Dean H. Gjerstad ◽  
John F. Dickson
Keyword(s):  
Leaf Area ◽  
Pinus Taeda ◽  
Loblolly Pine ◽  
Growth Efficiency ◽  
Biomass Partitioning ◽  
Lower Percentage ◽  
Total Biomass ◽  
Growth Responses ◽  
Area Index ◽  
Weed Interference

Three herbaceous regimes were established, using herbicides, to examine the effects of interference on growth and biomass partitioning in loblolly pine (Pinus taedaL.). Trees were sampled near Auburn and Tallassee, AL. Trees at the Auburn site grown with low weed interference (LWI) had 4, 10, 10, 8, and 4 times greater total aboveground biomass than did trees with high weed interference (HWI) for ages one through five, respectively. Medium weed interference (MWI, Auburn site only) resulted in three times greater biomass the first 4 yr and two times greater total biomass by the fifth year compared to trees grown with HWI. Trees growing with LWI were 5, 8, 10, and 6 times larger than those with HWI for ages one through four, respectively, at the Tallassee site. At all levels of interference, the percentage of total biomass in foliage decreased, and stem and branch components increased, with increasing tree size at both sites. Trees growing with HWI had a lower percentage of total biomass in foliage and a greater percentage of total biomass in stem than those growing with LWI when compared over a common size. Growth efficiency per tree, expressed as annual increase in stem biomass per unit leaf area (g m−2), was slightly greater for trees growing with LWI compared to HWI when leaf area index (LAI3, total surface) was less than 0.2. For LAI values greater than 0.2 the relationship was reversed. The latter contradicts the idea that growth efficiency can be used as a measure of vigor for young loblolly pine. Changes in carbon partitioning to the development of leaf area are suggested to be driving the accelerated growth responses associated with a reduction of weed interference.

Effects of ontogeny and soil nutrient supply on production, allocation, and leaf area efficiency in loblolly and slash pine stands

2000 ◽  
Vol 30 (10) ◽  
pp. 1511-1524 ◽  
Author(s):  
Eric J Jokela ◽  
Timothy A Martin
Keyword(s):  
Leaf Area ◽  
Weed Control ◽  
Loblolly Pine ◽  
Aboveground Biomass ◽  
Soil Nutrient ◽  
Growth Efficiency ◽  
Pinus Elliottii ◽  
Nutrient Supply ◽  
Slash Pine ◽  
Growth Responses

The effects of ontogeny and soil nutrient supply on aboveground biomass accumulation, allocation, and stemwood growth efficiency of loblolly (Pinus taeda L.) and slash pine (Pinus elliottii Engelm. var. elliottii) were investigated in north-central Florida over 16 years using a 2 × 2 × 2 factorial experiment (species, fertilization, weed control). Aboveground biomass growth responses to the combined fertilizer and weed control treatments (FW) averaged ~2- and 2.8-fold for slash and loblolly pine, respectively. In the same treatment, annual needlefall (NF) production for slash pine approached a "steady state" of 6 Mg·ha-1 at ages 8-14 years, while loblolly pine NF production peaked at 7 Mg·ha-1 at age 10 years, and then declined 17% following curtailment of the fertilizer treatment. Periodic stemwood biomass increment (PAI) for the FW treatment for both species culminated at about 15 Mg·ha-1·year-1 at age 8 years and then declined rapidly (~275%) to <4 Mg·ha-1·year-1 at 15 years; reductions for the untreated control were considerably slower. The progressive decline in PAI following peak leaf area development was closely associated with a decrease in stemwood production per unit leaf area (growth efficiency). A unit increase in leaf area index in the 7- to 9-year-old stands produced about 3.0 and 3.1 times more stemwood biomass per year than in the 14- to 16-year-old stands for loblolly and slash pine, respectively.

scholarly journals Aboveground biomass and leaf area index (LAI) mapping for Niassa Reserve, northern Mozambique

2008 ◽  
Vol 113 (G3) ◽  
Author(s):  
Natasha S. Ribeiro ◽  
Sassan S. Saatchi ◽  
Herman H. Shugart ◽  
Robert A. Washington-Allen
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Aboveground Biomass ◽  
Area Index

Impact of spectral saturation on leaf area index and aboveground biomass estimation of winter wheat

2016 ◽  
Vol 49 (4) ◽  
pp. 241-248 ◽  
Author(s):  
Chao Wang ◽  
Mei-Chen Feng ◽  
Wu-De Yang ◽  
Guang-Wei Ding ◽  
Hui Sun ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Aboveground Biomass ◽  
Biomass Estimation ◽  
Area Index
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