Relating Stocking and Density for Natural Regeneration of Conifers in Northern California

Abstract Natural regeneration cannot be effectively evaluated by tree density because of spatial heterogeneity typically observed. A proper interpretation of natural regeneration will consider some evaluation of area stocked. However, stocking estimates for natural regeneration are plot-size-dependent. Stocking at the 1-milacre scale is not generally comparable to that on a 4-milacre scale unless a generalized relation with stand density can be established. A generalized relation was first suggested to hold in a paper by Lynch and Schumacher (1941), but this has not been confirmed in subsequent studies. The Lynch and Schumacher hypothesis of a generalized regeneration density-stocking relation across plot size was tested using observations on 60 stands. Results were consistent with Lynch and Schumacher (1941). With evidence of a well-defined relation for plots ranging from 1 to 10 milacres, it appears possible to approximate, for ponderosa pine and associated species, the natural regeneration stocking percentage for a range of stocking standards based solely on observations of regeneration density. Confidence intervals were derived for a range of stocking standards in English units from 1 to 10 milacre and for metric units from 0.0005 hectares to 0.0040 hectares.

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Higher stand densities can promote soil carbon storage after conversion of temperate mixed natural forests to larch plantations

European Journal of Forest Research ◽

10.1007/s10342-020-01346-9 ◽

2020 ◽

Author(s):

Meng Na ◽

Xiaoyang Sun ◽

Yandong Zhang ◽

Zhihu Sun ◽

Johannes Rousk

Keyword(s):

Forest Management ◽

Soil Carbon ◽

Stand Density ◽

C Sequestration ◽

Tree Density ◽

Natural Forests ◽

Soil C ◽

C Storage ◽

Soil C Storage ◽

Soil C Sequestration

AbstractSoil carbon (C) reservoirs held in forests play a significant role in the global C cycle. However, harvesting natural forests tend to lead to soil C loss, which can be countered by the establishment of plantations after clear cutting. Therefore, there is a need to determine how forest management can affect soil C sequestration. The management of stand density could provide an effective tool to control soil C sequestration, yet how stand density influences soil C remains an open question. To address this question, we investigated soil C storage in 8-year pure hybrid larch (Larix spp.) plantations with three densities (2000 trees ha−1, 3300 trees ha−1 and 4400 trees ha−1), established following the harvesting of secondary mixed natural forest. We found that soil C storage increased with higher tree density, which mainly correlated with increases of dissolved organic C as well as litter and root C input. In addition, soil respiration decreased with higher tree density during the most productive periods of warm and moist conditions. The reduced SOM decomposition suggested by lowered respiration was also corroborated with reduced levels of plant litter decomposition. The stimulated inputs and reduced exports of C from the forest floor resulted in a 40% higher soil C stock in high- compared to low-density forests within 8 years after plantation, providing effective advice for forest management to promote soil C sequestration in ecosystems.

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Tree and opening spatial patterns vary by tree density in two old-growth remnant ponderosa pine forests in Northern Arizona, USA

Forest Ecology and Management ◽

10.1016/j.foreco.2019.117502 ◽

2019 ◽

Vol 450 ◽

pp. 117502 ◽

Cited By ~ 1

Author(s):

Jose M. Iniguez ◽

James F. Fowler ◽

W. Keith Moser ◽

Carolyn H. Sieg ◽

L. Scott Baggett ◽

...

Keyword(s):

Spatial Patterns ◽

Ponderosa Pine ◽

Tree Density ◽

Pine Forests ◽

Old Growth ◽

Ponderosa Pine Forests ◽

Northern Arizona

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Naturally Seeded versus Planted Ponderosa Pine Seedlings in Group-Selection Openings

Western Journal of Applied Forestry ◽

10.1093/wjaf/24.1.48 ◽

2009 ◽

Vol 24 (1) ◽

pp. 48-54 ◽

Cited By ~ 6

Author(s):

Philip M. McDonald ◽

Gary Fiddler ◽

Martin Ritchie ◽

Paula Anderson

Keyword(s):

Growth Rate ◽

Plant Community ◽

Ponderosa Pine ◽

Natural Regeneration ◽

Group Selection ◽

Average Density ◽

Stem Diameter ◽

Diameter Growth ◽

Pine Seedlings ◽

Survival And Growth

Abstract The purpose of this article was to determine whether natural regeneration or planted seedlings should be used in group-selection openings. The answer depends on the survival and growth rate of both types of seedlings, and that could depend on the size of the openings and the effect of trees on their edge. In this side-by-side study, the natural pine seedlings originated from the 1988 seed crop and the 1–0 nursery-grown seedlings were outplanted in spring 1989. Openings ranged from 0.01 to 0.65 ha. The plant community consisted of many species of shrubs, forbs, and grasses with manzanita having the highest density and greatest development. After 9 years, manzanita had an average density of 13,870 plants/ha, 2,050 m2/ha of foliar cover, and was 125 cm tall. From 1990 to 1997, planted ponderosa pine seedlings were taller (P < 0.05) than natural seedlings, and from 1995 to 1997, mean stem diameter at 30 cm of planted seedlings was larger than natural counterparts (P < 0.05). Development for 1 year in the nursery apparently gave the planted seedlings a growth advantage over the natural seedlings. For natural seedlings, distance from opening edge had little effect on pine height or diameter growth regardless of opening size. Planted seedlings, however, appeared to increase in height and diameter growth with both opening size and distance from edge.

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Implications of Reduced Stand Density on Tree Growth and Drought Susceptibility: A Study of Three Species under Varying Climate

Forests ◽

10.3390/f11060627 ◽

2020 ◽

Vol 11 (6) ◽

pp. 627

Author(s):

Mathias Steckel ◽

W. Keith Moser ◽

Miren del Río ◽

Hans Pretzsch

Keyword(s):

Scots Pine ◽

Tree Growth ◽

Water Availability ◽

Ponderosa Pine ◽

Stand Density ◽

Stand Age ◽

Short Term ◽

Sessile Oak ◽

Site Water ◽

Positive Effect

A higher frequency of increasingly severe droughts highlights the need for short-term measures to adapt existing forests to climate change. The maintenance of reduced stand densities has been proposed as a promising silvicultural tool for mitigating drought stress. However, the relationship between stand density and tree drought susceptibility remains poorly understood, especially across ecological gradients. Here, we analysed the effect of reduced stand density on tree growth and growth sensitivity, as well as on short-term drought responses (resistance, recovery, and resilience) of Scots pine (Pinus sylvestris L.), sessile oak (Quercus petraea (Matt.) Liebl.), and ponderosa pine (Pinus ponderosa Douglas ex C. Lawson). Tree ring series from 409 trees, growing in stands of varying stand density, were analysed at sites with different water availability. For all species, mean tree growth was significantly higher under low compared with maximum stand density. Mean tree growth sensitivity of Scots pine was significantly higher under low compared with moderate and maximum stand density, while growth sensitivity of ponderosa pine peaked under maximum stand density. Recovery and resilience of Scots pine, as well as recovery of sessile oak and ponderosa pine, decreased with increasing stand density. In contrast, resistance and resilience of ponderosa pine significantly increased with increasing stand density. Higher site water availability was associated with significantly reduced drought response indices of Scots pine and sessile oak in general, except for resistance of oak. In ponderosa pine, higher site water availability significantly lessened recovery. Higher site water availability significantly moderated the positive effect of reduced stand density on drought responses. Stand age had a significantly positive effect on the resistance of Scots pine and a negative effect on recovery of sessile oak. We discuss potential causes for the observed response patterns, derive implications for adaptive forest management, and make recommendations for further research in this field.

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Effect of Stand Density on Water Use of Mulga (Acacia aneura F.muell.) Woodlands in South-Western Queensland

Australian Journal of Botany ◽

10.1071/bt9760177 ◽

1976 ◽

Vol 24 (2) ◽

pp. 177 ◽

Cited By ~ 10

Author(s):

AJ Pressland

Keyword(s):

Soil Moisture ◽

Water Use ◽

Stand Density ◽

Tree Density ◽

Pan Evaporation ◽

Permanent Wilting Point ◽

The Mean ◽

Acacia Aneura ◽

Soil Moisture Status ◽

Wilting Point

The important Australian fodder tree mulga (Acacia aneura F. Muell.) was thinned to densities ranging between 0 and 4000 trees ha-1 near Charleville, Queensland. Water use by the ensuing communities was studied from December 1971 to October 1973. Evapotranspiration over this 22 month period increased with tree density from 814 mm for the totally cleared plots to 852 and 891 mm for those plots supporting 4000 and 640 trees ha-1 respectively. Regression analysis was used to relate soil moisture to time since rain; it was established that the soil had dried to its permanent wilting point within 60 days of rain sufficient to recharge the soil to a depth of 135 cm. The mean apparent maximum evapotranspiration of the mulga communities was 4.7 mm day-1. The ratios of evapotranspiration to pan evaporation (Et/Eo) were influenced by both soil moisture status and tree density. Et/Eo ratios ranged between 0.55 and 0.07 in the summer of 1972, and between 1.05 and 0.05 the following summer. In the winters of 1972 and 1973 Et/Eo ratios ranged between 0.92 and 0.04, and 1.33 and 0.09 respectively. The significance of the results to production and management of mulga lands in south-western Queensland is discussed.

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Corrigendum to: Assessing canopy fuel stratum characteristics in crown fire prone fuel types of western North America

International Journal of Wildland Fire ◽

10.1071/wf02024_co ◽

2010 ◽

Vol 19 (1) ◽

pp. iii ◽

Cited By ~ 1

Author(s):

Miguel G. Cruz ◽

Martin E. Alexander ◽

Ronald H. Wakimoto

Keyword(s):

Ponderosa Pine ◽

Fire Management ◽

Linear Regression Analysis ◽

Basal Area ◽

Stand Density ◽

Fuel Load ◽

Tree Level ◽

Management Decision ◽

Crown Fire ◽

In Fire

Application of crown fire behavior models in fire management decision-making have been limited by the difficulty of quantitatively describing fuel complexes, specifically characteristics of the canopy fuel stratum. To estimate canopy fuel stratum characteristics of four broad fuel types found in the western United States and adjacent areas of Canada, namely Douglas-fir, ponderosa pine, mixed conifer, and lodgepole pine forest stands, data from the USDA Forest Service's Forest Inventory and Analysis (FIA) database were analysed and linked with tree-level foliage dry weight equations. Models to predict canopy base height (CBH), canopy fuel load (CFL) and canopy bulk density (CBD) were developed through linear regression analysis and using common stand descriptors (e.g. stand density, basal area, stand height) as explanatory variables. The models developed were fuel type specific and coefficients of determination ranged from 0.90 to 0.95 for CFL, between 0.84 and 0.92 for CBD and from 0.64 to 0.88 for CBH. Although not formally evaluated, the models seem to give a reasonable characterization of the canopy fuel stratum for use in fire management applications.

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Stand density, drought, and herbivory constrain ponderosa pine regeneration pulse

Canadian Journal of Forest Research ◽

10.1139/cjfr-2019-0248 ◽

2020 ◽

Vol 50 (9) ◽

pp. 862-871 ◽

Cited By ~ 3

Author(s):

Thomas E. Kolb ◽

Kelsey Flathers ◽

John B. Bradford ◽

Caitlin Andrews ◽

Lance A. Asherin ◽

...

Keyword(s):

Pinus Ponderosa ◽

Ponderosa Pine ◽

Seedling Survival ◽

Stand Density ◽

Survival Duration ◽

Northern Arizona ◽

Growing Seasons ◽

Pine Regeneration ◽

Stand Thinning ◽

Survival And Growth

Trees in dry forests often regenerate in episodic pulses when wet periods coincide with ample seed production. Factors leading to success or failure of regeneration pulses are poorly understood. We investigated the impacts of stand thinning on survival and growth of the 2013 cohort of ponderosa pine (Pinus ponderosa Douglas ex P. Lawson & C. Lawson) seedlings in northern Arizona, United States. We measured seedling survival and growth over the first five growing seasons after germination in six stand basal areas (BAs; 0, 7, 14, 23, 34, and 66 (unthinned) m2·ha−1) produced by long-term experimental thinnings. Five-year survival averaged 2.5% and varied among BAs. Mean survival duration was longer in intermediate BAs (11 to 16 months) than in clearings and high BAs (5 months). The BAs of 7, 14, and 23 m2·ha−1 had >2600 5-year-old seedlings·ha−1. In contrast, regeneration was lower in the clearing (666 seedlings·ha−1) and failed completely in the 34 m2·ha−1 and unthinned treatments. Seedling survival was highest during wet years and lowest during drought years. Many surviving seedlings had no net height growth between years 4 and 5 because of stem browsing. Results indicate that natural regeneration of ponderosa pine is influenced by stand BA, drought, herbivory, and interactions between extreme climatic events.

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Productivity in the first seven years of a Pinus radiata-annual pasture agroforest in Western Australia

Australian Journal of Experimental Agriculture ◽

10.1071/ea9870231 ◽

1987 ◽

Vol 27 (2) ◽

pp. 231 ◽

Cited By ~ 14

Author(s):

GW Anderson ◽

RW Moore

Keyword(s):

Pinus Radiata ◽

Carrying Capacity ◽

Light Transmission ◽

Stand Density ◽

Tree Density ◽

High Density ◽

Diameter Growth ◽

Farm Scale ◽

On Farm

Pinus radiata seedlings were planted into an annual pasture at low, medium and high densities. The trees were pruned annually from year 4 and those with poor form were progressively culled until final stand densities of 75, 150 and 225 trees ha-1 were achieved 7 years after planting. The pastures were grazed by sheep from year 4. The sheep carrying capacities of the pastures declined as tree density increased because of competition between trees and pasture and also because of debris from thinning and pruning. In year 7, under the high density trees, the sheep carrying capacity of the pastures was 73% and light transmission was 69% of that of control pastures (no trees) and debris covered about 22% of the pasture. Diameter growth measurements from year 5 to 7 were 7.65, 7, 45 and 6.35 cm for low, medium and high density of trees respectively, which indicates that competition between trees had commenced at the high density (P<0.05). There was little conflict between the agricultural and forestry components at the low stand density with satisfactory production from both. This system has the potential to generate annual income to offset pine establishment and silvicultural costs while providing another source of income in the long term. It is being tried on farm scale by some landholders wishing to diversify from grazing-only enterprises.

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Conifer seed predation in harvested and burned dry Douglas-fir forests in southern British Columbia

Canadian Journal of Forest Research ◽

10.1139/x09-084 ◽

2009 ◽

Vol 39 (8) ◽

pp. 1548-1556 ◽

Cited By ~ 2

Author(s):

David J. Huggard ◽

André Arsenault

Keyword(s):

Pinus Ponderosa ◽

Seed Predation ◽

Ponderosa Pine ◽

Natural Regeneration ◽

Woody Debris ◽

Survival Rates ◽

Forest Litter ◽

Douglas Fir ◽

Burned Area ◽

Clear Cut

Consumption of seeds of Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco) and ponderosa pine ( Pinus ponderosa Dougl. ex P. & C. Laws.) was measured in dry Douglas-fir forest at the Opax Mountain Silvicultural Systems site and a nearby burned area as one component of understanding limited natural regeneration in these sites. Seeds were placed in plots surrounded by a physical barrier to invertebrates, enclosed in mesh impermeable to small mammals, covered by litter, or unprotected in clear-cut, partially harvested, uncut, and burned areas and monitored for three several-day sessions in 2 years. Daily survival rates of unprotected seeds of both species were equally low: 0.63 in uncut forest, 0.45 in partially harvested and clear-cut sites, and 0.03 in the burned area. Experimental reductions of coarse woody debris reduced seed predation moderately in patch cuts but not in uncut forest. Litter cover or selective exclosure of ground-dwelling invertebrates reduced seed losses only slightly, whereas small mammal exclosures eliminated most seed loss. Deer mice ( Peromyscus maniculatus Wagner) are likely the most important seed predators. High rates of seed predation in dry Douglas-fir forests likely limit natural regeneration in harvested and burned stands.

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