Clumped or regular? the role of thinning pattern on pine growth and soil water content in dense Aleppo pine post-fire stands

AbstractThe development of silvicultural practices that seek to promote structural heterogeneity is increasingly demanded. This work investigates the effect of thinning spatial pattern on the response to pre-commercial thinning of dense Aleppo pine post-fire stands. On three replicated experimental sites in SE Spain, we applied the following treatments: 600 trees/ha, regular thinning pattern (600R), with residual trees evenly spaced; 600 trees/ha, aggregated thinning pattern (600A), with residual pines arranged in clumps of ∽25 trees with a local within-clump density of 2500 trees/ha; and control treatment, with no thinning applied (> 20,000 trees/ha). We assessed treatment effects on pine growth, size-growth relationships, soil water content, and understory vegetation over the first three years after thinning application. Both regular and aggregated thinning pattern similarly increased pine radial growth. In general, dbh growth rates in response to thinning were faster for smaller trees than for larger trees. The growth rate of pine height was higher for 600R and control than for 600A, indicating a positive effect on height of both low and very high pine densities. We found a near-term positive effect of aggregated pattern on water availability at the stand level, mostly resulting from enhanced soil water content in the canopy gaps. For both thinning patterns, the recovery of understory vegetation was dominated by resprouter species. This study highlights the potential of aggregated thinning patterns to enhance the complexity and heterogeneity of the pine stands without compromising pine growth, which could be of great use to managing pine forests in Mediterranean areas.

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Overstory–Understory Vegetation Cover and Soil Water Content Observations in Western Juniper Woodlands: A Paired Watershed Study in Central Oregon, USA

Forests ◽

10.3390/f10020151 ◽

2019 ◽

Vol 10 (2) ◽

pp. 151 ◽

Cited By ~ 6

Author(s):

Grace Ray ◽

Carlos G. Ochoa ◽

Tim Deboodt ◽

Ricardo Mata-Gonzalez

Keyword(s):

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Soil Texture ◽

Canopy Cover ◽

Understory Vegetation ◽

Watershed Scale ◽

Shrub Cover ◽

Western Juniper ◽

Tree Canopy Cover

The effects of western juniper (Juniperus occidentalis) control on understory vegetation and soil water content were studied at the watershed-scale. Seasonal differences in topsoil (12 cm) water content, as affected by vegetation structure and soil texture, were evaluated in a 96-ha untreated watershed and in a 116-ha watershed where 90% juniper was removed in 2005. A watershed-scale characterization of vegetation canopy cover and soil texture was completed to determine some of the potential driving factors influencing topsoil water content fluctuations throughout dry and wet seasons for approximately one year (2014–2015). We found greater perennial grass, annual grass, and shrub cover in the treated watershed. Forb cover was no different between watersheds, and as expected, tree canopy cover was greater in the untreated watershed. Results also show that on average, topsoil water content was 1% to 3% greater in the treated watershed. The exception was during one of the wettest months (March) evaluated, when soil water content in the untreated watershed exceeded that of the treated by <2%. It was noted that soil water content levels that accumulated in areas near valley bottoms and streams were greater in the treated watershed than in the untreated toward the end of the study in late spring. This is consistent with results obtained from a more recent study where we documented an increase in subsurface flow residence time in the treated watershed. Overall, even though average soil water content differences between watersheds were not starkly different, the fact that more herbaceous vegetation and shrub cover were found in the treated watershed led us to conclude that the long-term effects of juniper removal on soil water content redistribution throughout the landscape may be beneficial towards restoring important ecohydrologic connections in these semiarid ecosystems of central Oregon.

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Multi-channel GPR to assess the influence of shallow structural heterogeneity on spatio-temporal variations of near-surface soil water content

2012 14th International Conference on Ground Penetrating Radar (GPR) ◽

10.1109/icgpr.2012.6254944 ◽

2012 ◽

Cited By ~ 2

Author(s):

Xicai Pan ◽

P. Klenk ◽

K. Roth ◽

Jiabao Zhang ◽

Ping Huang ◽

...

Keyword(s):

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Surface Soil ◽

Structural Heterogeneity ◽

Temporal Variations ◽

Near Surface ◽

Spatio Temporal

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Effects of Throughfall Exclusion on Soil Respiration in a Moso Bamboo Forest Soil in Southeast China

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.726-731.3762 ◽

2013 ◽

Vol 726-731 ◽

pp. 3762-3766

Author(s):

Qian Li ◽

Ben Zhi Zhou ◽

Xiao Ming Wang ◽

Xiao Gai Ge ◽

Yong Hui Cao

Keyword(s):

Soil Respiration ◽

Soil Temperature ◽

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Bamboo Forest ◽

Monthly Variation ◽

Exclusion Experiment ◽

Throughfall Exclusion ◽

And Control

Both soil temperature and soil water condition are important factors that influence soil respiration at different forest. In this study, a throughfall exclusion experiment was carried out to explore effects of increased soil temperature and decreased soil water content on soil respirations in the bamboo forest in North Zhejiang of China. The results showed that 1) monthly variation in soil respiration ranges from 2.00 to 0.63μmol·m-2·s-1 and 2.20 to 0.66μmolm-2s-1in throughfall exclusion and control plots respectively. The soil respiration monthly variation following the monthly variation of soil temperature and in contrast to the monthly soil water content. 2) Soil temperature can explain 65.5%and 73.9% of the variance of soil respiration in throughfall exclusion and control plots respectively. Multivariate linear model based on temperature and soil water content explained 66.9% and 73.4% of the variance of soil respiration in throughfall exclusion and control plots respectively. Soil water content had no significant relationship with soil respiration. Q10 values of throughfall exclusion and control plots were 5.99 and 4.44.

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Belowground competition influences growth of natural regeneration in thinned Douglas-fir stands

Canadian Journal of Forest Research ◽

10.1139/x08-150 ◽

2008 ◽

Vol 38 (12) ◽

pp. 3085-3097 ◽

Cited By ~ 19

Author(s):

Warren D. Devine ◽

Timothy B. Harrington

Keyword(s):

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Nitrogen Concentration ◽

Nitrogen Deficiency ◽

Douglas Fir ◽

Understory Vegetation ◽

Detectable Effect ◽

Belowground Competition ◽

Overstory Trees

Using a factorial combination of understory removal and trenching treatments, we examined the influences of belowground competition from understory and overstory vegetation on growth of naturally established Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco var. menziesii) saplings in thinned stands of Douglas-fir on moderately productive, glacially derived soils near Tacoma, Washington. Under limited light (26% ± 16% of full sun), sapling height and diameter growth were significantly reduced by belowground competition from overstory trees. Regardless of presence or absence of belowground competition from trees, understory vegetation did not have a detectable effect on sapling growth. Nitrogen deficiency in saplings was not detected in the presence of belowground competition: where tree roots were excluded, foliar nitrogen concentration and content increased without an increase in foliar mass. Belowground competition from overstory trees had a greater negative effect on growing season soil water content than did understory vegetation. Under the conditions of restricted light availability in this study, limitations in soil water content from competition had a strong growth-limiting effect on Douglas-fir regeneration. As potential canopy trees in a future uneven-aged stand, this sapling cohort would benefit from root gaps created during harvests.

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Patterns of Soil and Tree Water Status and Leaf Functioning during Regulated Deficit Irrigation Scheduling in Peach

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.118.5.580 ◽

1993 ◽

Vol 118 (5) ◽

pp. 580-586 ◽

Cited By ~ 51

Author(s):

J. Girona ◽

M. Mata ◽

D.A. Goldhamer ◽

R.S. Johnson ◽

T.M. DeJong

Keyword(s):

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Deficit Irrigation ◽

Prunus Persica ◽

Irrigation Treatment ◽

Irrigation Scheduling ◽

Water Infiltration ◽

Control Treatment ◽

Regulated Deficit Irrigation

Seasonal patterns of soil water content and diurnal leaf water potential (LWP), stomatal conductance(gs), and net CO2 assimilation (A) were determined in a high-density peach [Prunus persica(L) Batsch cv. Cal Red] subjected to regulated deficit irrigation scheduling. The regulated deficit irrigation treatment caused clear differences in soil water content and predawn LWP relative to control irrigation treatments. Treatment differences in midday LWP, gs, and A were also significant, but not as distinct as differences in predawn LWP. Leaves on trees subject of the deficit irrigation treatment were photosynthetically more water-use-efficient during the latter part of the stress period than were the nonstressed trees. Midday LWP and gs, on trees that received the regulated deficit irrigation treatment did not recover to control treatment values until more than 3 weeks after full irrigation was resumed at the beginning of state III of fruit growth, because of water infiltration problems in the dry soil caused by the deficit irrigation. The regulated deficit irrigation treatment caused only a 8% reduction in trunk growth relative to the control, but resulted in a 40% savings in irrigation requirements.

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SOIL WATER CONTENT AFFECTS THE AVAILABILITY OF PHOSPHATE

Proceedings of the New Zealand Grassland Association ◽

10.33584/jnzg.1985.46.1696 ◽

1985 ◽

pp. 185-189

Author(s):

M.C.H.Mouat Pieter Nes

Keyword(s):

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Soil Solution ◽

Equivalent Reduction

Reduction in water content of a soil increased the concentration of ammonium and nitrate in solution, but had no effect on the concentration of phosphate. The corresponding reduction in the quantity of phosphate in solution caused an equivalent reduction in the response of ryegrass to applied phosphate. Keywords: soil solution, soil water content, phosphate, ryegrass, nutrition.

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Effect of inter-row cultivation on soil carbon dioxide emission in a peach plantation

Agrokémia és Talajtan ◽

10.1556/agrokem.59.2010.1.19 ◽

2010 ◽

Vol 59 (1) ◽

pp. 157-164 ◽

Cited By ~ 1

Author(s):

E. Tóth ◽

Cs. Farkas

Keyword(s):

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Carbon Dioxide Emission ◽

Nutrient Content ◽

Soil Disturbance ◽

Biological Properties ◽

Soil Tillage ◽

Favourable Effect ◽

Volumetric Soil Water Content

Soil biological properties and CO2emission were compared in undisturbed grass and regularly disked rows of a peach plantation. Higher nutrient content and biological activity were found in the undisturbed, grass-covered rows. Significantly higher CO2fluxes were measured in this treatment at almost all the measurement times, in all the soil water content ranges, except the one in which the volumetric soil water content was higher than 45%. The obtained results indicated that in addition to the favourable effect of soil tillage on soil aeration, regular soil disturbance reduces soil microbial activity and soil CO2emission.

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