Development of Redwood Regeneration after Conifer Partial Harvest and Hardwood Management

Abstract Harvesting of commercial conifer species from conifer-hardwood mixtures can leave residual stands dominated by hardwoods. Removing unwanted hardwoods by cutting or herbicide makes growing space available to residual trees and regeneration and can restore conifer dominance. Forest managers of north coastal California need guidance on how such treatments affect subsequent growth of planted redwoods (Sequoia sempervirens [D. Don.] Endl.) or natural regeneration, as well as proliferation of undesirable species. Our observational study reconstructed growth of 108 regenerating redwoods in 26 treated stands. Residual stand density was the main driver of height and diameter growth in the new cohort of redwoods, irrespective of whether hardwoods were cut or received herbicide frill treatment (prevents resprouting). At lower residual stand densities, there were higher densities of natural regeneration (ingrowth) of conifers and hardwoods, which affected diameter at breast height (dbh) growth of regenerating redwoods. After heavier cutting of hardwoods, this ingrowth comprised a greater proportion of unwanted hardwood regeneration. Therefore, frill treatment is recommended when the objective of management is to reduce hardwood stocking and regeneration. Combining partial harvesting of conifers with cutting or frill treatment of hardwood is another option that reduces stand density to promote height and dbh growth of regenerating redwoods. Study Implications Redwood is a valuable commercial species in California Coast Range forests, but its regeneration often competes with unwanted hardwoods. The most influential solution is reducing stand density. Treatment choice is less influential, giving managers some flexibility. For example, stand density can be reduced by cutting a mix of conifers and hardwoods, or by herbicide frill treatment of hardwoods to release conifers, or some combination of these two treatments. After cutting, hardwoods resprout, leading to higher hardwood densities in the understory and slightly slower regeneration of redwood. Conversely, herbicide frill treatment promotes conifer dominance by removing hardwood trees and regeneration.

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Forest Regrowth on the Cumberland Plateau and Implications for Productive Management

Southern Journal of Applied Forestry ◽

10.1093/sjaf/7.4.208 ◽

1983 ◽

Vol 7 (4) ◽

pp. 208-212 ◽

Cited By ~ 1

Author(s):

Robert N. Muller

Keyword(s):

Species Composition ◽

Basal Area ◽

Stand Density ◽

Cumberland Plateau ◽

Old Growth ◽

Nutrient Pools ◽

Old Growth Forest ◽

Composition And Structure ◽

Second Growth ◽

Commercial Species

Abstract An old-growth forest and a 35-year-old, second-growth forest on the Cumberland Plateau were studied to compare species composition and structure. Species composition and total basal area of the two stands did not differ, although total stand density was 19 percent lower and basal area of commercial species was 25 percent higher in the old-growth than in the second-growth stand. Analysis of size-class distributions showed that both stands were best represented by an inverse J-shaped distribution, which best describes old-age stands. The rapid regeneration of the second-growth stand seems to be the result of minimal disturbance to accumulated nutrient pools in the soil. The importance of these accumulated nutrient pools and implications for forest management on the Cumberland Plateau are discussed.

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Growth and mortality response of forest regeneration to partial harvesting varies by species’ shade tolerance

Canadian Journal of Forest Research ◽

10.1139/cjfr-2020-0022 ◽

2020 ◽

Vol 50 (10) ◽

pp. 1081-1092 ◽

Cited By ~ 2

Author(s):

Arun K. Bose ◽

Andrew S. Nelson ◽

Matthew G. Olson

Keyword(s):

High Intensity ◽

Natural Regeneration ◽

Shade Tolerance ◽

Basal Area ◽

Permanent Plots ◽

Partial Harvesting ◽

Before And After ◽

Forested Landscapes ◽

Harvesting Intensity ◽

Stand Attributes

Does species’ shade tolerance regulate natural regeneration abundance and composition when partial harvestings (≤80% of basal area removal) are operated on a landscape scale? We examined this question using 835 permanent plots located across forested landscapes of Maine, USA. These plots were surveyed for regeneration growth, mortality, and recruitment before and after treatment application (i.e., partially harvested and unharvested). Our results showed that relative to unharvested stands, high-intensity partial harvesting (41%–80% of basal area removal) increased the number of seedlings (diameter at breast height (DBH) < 2.5 cm) recruited to saplings (DBH of 2.5–12.69 cm) and sapling diameter growth irrespective of species’ shade tolerance over a 15-year period after treatment. However, high-intensity partial harvesting increased sapling mortality during the initial 5 years since harvesting, whereas low-intensity partial harvesting (5%–40% of basal area removal) maintained the natural regeneration dynamics (growth, recruitment, and mortality) of unharvested stands. We found that harvesting intensity, basal area, and seedling density by shade-tolerance group before harvesting are more important attributes than species’ shade tolerance for determining the responses of natural regeneration to partial harvesting. The greater importance of preharvest stand attributes on postharvest regeneration may suggest an integrated overstory and understory manipulation approach for attaining the desired regeneration composition.

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Regeneration of salal (Gaultheria shallon) in the central Coast Range forests of Oregon

Canadian Journal of Botany ◽

10.1139/b94-006 ◽

1994 ◽

Vol 72 (1) ◽

pp. 39-51 ◽

Cited By ~ 36

Author(s):

David W. Huffman ◽

John C. Tappeiner II ◽

John C. Zasada

Keyword(s):

Seedling Establishment ◽

Basal Area ◽

Stand Density ◽

Total Biomass ◽

Coast Range ◽

Site Location ◽

Gaultheria Shallon ◽

Central Coast ◽

Aerial Stem ◽

Rhizome Biomass

Regeneration of salal (Gaultheria shallon Pursh.) by seedling establishment and vegetative expansion was examined under various forest conditions in the central Coast Range of Oregon. Size and expansion rate of individual clonal fragments were negatively correlated with overstory stand density (p ≤ 0.039). As overstory basal area increased from 25 to 75 m2/ha, mean annual growth percentage of clone rhizome systems decreased from 23.7 to 0.0% and mean total rhizome length decreased from 102 to 0.89 m. Interclonal competition in dense clumps of salal apparently causes rhizomes to die and clones to fragment. In these patches, rhizome biomass and density, aerial stem biomass and density, and total biomass were negatively correlated with overstory density (p ≤ 0.01). For example, in clearcuts, salal clumps had up to 177.7 m rhizome/m2 and 346 stems/m2, whereas patches under dense overstories had as few as 10.6 m rhizome/m2 and 19 stems/m2. Aerial stem populations had uneven-age distributions of aerial stems in all overstory conditions. This structure is apparently maintained through annual production of new ramets. Salal seedling establishment rates were significantly affected by study site location, overstory density, and substrate (p ≤ 0.05). Two-year survival was highest on rotten logs and stumps in thinned stands. Key words: clonal morphology, clone populations, Douglas-fir forests, Gaultheria shallon, seedling establishment, vegetative expansion.

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Distribution and occurrence of western gall rust in thinned jack pine stands

The Forestry Chronicle ◽

10.5558/tfc70788-6 ◽

1994 ◽

Vol 70 (6) ◽

pp. 788-794 ◽

Cited By ~ 3

Author(s):

S. C. Hills ◽

D. M. Morris ◽

C. Bowling

Keyword(s):

Infection Rate ◽

Pinus Banksiana ◽

Stand Density ◽

Jack Pine ◽

Pissodes Strobi ◽

Northwestern Ontario ◽

Commercial Thinning ◽

Endocronartium Harknessii ◽

Commercial Species ◽

Stem Gall

Jack pine (Pinus banksiana Lamb.) is one of the most important commercial species in northwestern Ontario and is the principal host of one of the most serious stem rusts, western gall rust (WGR) caused by Endocronartium harknessii (J.P. Moore) Y. Hirat. In 1986 a trial was established to determine, in part, effects of precommercial thinning on the distribution and occurrence of WGR in jack pine. A 9 year-old aerially seeded jack pine stand was thinned to square spacings of 1 m, 1.5 m, 2 m, 2.5 m, 3 m and a control. Fifth-year results indicated that a significant quadratic trend (p = 0.014) existed between spacing and stem gall infection rate. The incidence of WGR (stem galls) increased as stand density decreased to a maximum at 1.5 m spacing, and then declined to roughly the infection rate of the control at the lowest density (3 m). A significant relationship (0.084) between crown class and the rate of branch gall infection rate was also detected. The branch gall infection rate decreased from 6.2% year−1 for dominant trees to 2.8% year−1 for trees categorized as suppressed. Based on these results, pre-commercial thinning operations should target those trees with main stem galls and/or numerous branch galls, regardless of size and crown position, and then focus on the removal of suppressed trees to meet the desired density target. This strategy should not only enhance growth of the remaining trees, but also reduce WGR inoculum levels and reduce future WGR-related mortality. Key words: jack pine (Pinus banksiana Lamb.), western gall rust (Endocronartium harknessii (J.R Moore) Y. Hirat.), pre-commercial thinning, white pine weevil (Pissodes strobi Peck.)

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Residual-tree growth responses to partial stand harvest in the black spruce (Picea mariana) boreal forestThis article is one of a selection of papers published in the Special Forum IUFRO 1.05 Uneven-Aged Silvicultural Research Group Conference on Natural Disturbance-Based Silviculture: Managing for Complexity.

Canadian Journal of Forest Research ◽

10.1139/x07-148 ◽

2007 ◽

Vol 37 (9) ◽

pp. 1563-1571 ◽

Cited By ~ 34

Author(s):

H. C. Thorpe ◽

S. C. Thomas ◽

J. P. Caspersen

Keyword(s):

Boreal Forest ◽

Tree Growth ◽

Picea Mariana ◽

Radial Growth ◽

Growth Response ◽

Black Spruce ◽

Tree Age ◽

Growth Responses ◽

Partial Harvest ◽

Partial Harvesting

Variants of partial harvesting are gaining favour as means to balance ecosystem management and timber production objectives on managed boreal forest landscapes. Understanding how residual trees respond to these alternative silvicultural treatments is a critical step towards evaluating their potential from either a conservation or a wood supply perspective. We used dendroecological techniques combined with a chronosequence approach to quantify the temporal radial growth response pattern of residual black spruce ( Picea mariana (Mill.) BSP) trees to partial harvest in northeastern Ontario. At its peak, 8–9 years after harvest, radial growth of residual trees had doubled. The growth pattern was characterized by a 2-year phase of no response, a subsequent period of increase 3–9 years after harvest, and a stage of declining rates 10–12 years after harvest. The magnitude of tree growth response depended strongly on tree age: peak postharvest growth was substantially higher for young trees, while old trees displayed only modest growth increases. Both the large magnitude and the time delay in postharvest growth responses have important implications for the development of more accurate quantitative tools to project future yields and, more generally, for determining whether partial harvesting is a viable management option for the boreal forest.

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Operational and economic feasibility of logging within forested riparian zones

The Forestry Chronicle ◽

10.5558/tfc86601-5 ◽

2010 ◽

Vol 86 (5) ◽

pp. 601-607 ◽

Cited By ~ 6

Author(s):

Stephen B. Holmes ◽

David P. Kreutzweiser ◽

Peter S. Hamilton

Keyword(s):

Stand Structure ◽

Basal Area ◽

Partial Solution ◽

Economic Feasibility ◽

Riparian Zones ◽

Environmental Consequences ◽

Partial Harvest ◽

Partial Harvesting ◽

Machine Productivity ◽

Average Size

The placement of riparian setbacks around water bodies has been shown to reduce logging impacts on aquatic and riparian communities and processes. However, the systematic application of no-harvest riparian setbacks can result in unnatural, linear patterns of older-growth forest across the landscape, a pattern that is inconsistent with the goal of emulating natural disturbances. Partial harvesting within riparian zones could provide a partial solution to this problem. As part of a larger project to evaluate the environmental consequences of partial harvesting within stream riparian zones of boreal mixedwood forests, we measured wood volumes removed from riparian zones and compared feller buncher productivity between partially harvested riparian zones and adjacent clearcut uplands. On average, from 20% to 33% of the total basal area (27% to 39% of the spruce/pine/fir basal area) was removed from the riparian zones. The riparian harvest resulted in considerable heterogeneity in residual stand structure, however, with basal areas within 50-m segments along the streams ranging from just over 50% to >95% remaining. Our results suggest that, even though the absolute effort required to harvest trees was greater in riparian zones, the larger average size of the trees more than compensated, so that the wood volume removed per unit effort was higher in riparian zones than in clearcuts. Key words: machine productivity, partial harvest, residual stand structure, riparian zone

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

Forest Science ◽

10.1093/forsci/fxaa005 ◽

2020 ◽

Vol 66 (5) ◽

pp. 521-525 ◽

Cited By ~ 1

Author(s):

Martin W Ritchie

Keyword(s):

Spatial Heterogeneity ◽

Confidence Intervals ◽

Ponderosa Pine ◽

Natural Regeneration ◽

Stand Density ◽

Tree Density ◽

Size Dependent ◽

Plot Size ◽

Associated Species ◽

Proper Interpretation

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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Partial harvesting in the Canadian boreal: Success will depend on stand dynamic responses

The Forestry Chronicle ◽

10.5558/tfc83319-3 ◽

2007 ◽

Vol 83 (3) ◽

pp. 319-325 ◽

Cited By ~ 52

Author(s):

H C Thorpe ◽

S C Thomas

Keyword(s):

Boreal Forest ◽

Boreal Forests ◽

Biological Diversity ◽

Empirical Studies ◽

Natural Disturbance ◽

Dynamic Responses ◽

Post Harvest ◽

Partial Harvest ◽

Partial Harvesting ◽

Structural Retention

In the past 10 to 15 years, alternative silvicultural treatments involving partial harvesting have been developed for boreal forests, with the goal of achieving a balance between biodiversity maintenance and continued timber production. Most prior research has focussed on the impacts of partial harvesting on biological diversity, while stand dynamic responses remain little studied. In this paper we explore partial stand harvesting in the Canadian boreal—its rationale, current extent, and impact on stand dynamic patterns. Empirical studies from the boreal and elsewhere indicate that residual trees of many species respond to partial harvesting with enhanced growth, commonly showing a lagged response after which peak growth occurs five to 25 years following harvest. Post-harvest mortality is also prevalent but much more variable, with losses of residual trees ranging from nearly zero to more than 50% above background mortality rates in the initial years following harvest. With the exception of strip cutting in parts of northern Ontario and Quebec (HARP/CPPTM), operational partial harvesting in the Canadian boreal currently involves very low levels of retention. Available data suggest that such low retention levels, particularly when spatially dispersed, generally result in unacceptably high rates of post-harvest mortality, which are unlikely to be offset by increases in residual tree growth. There is an urgent need for development of spatially explicit stand simulation models that will allow accurate yield predictions for partial harvest systems to assess their feasibility in boreal forest management. Key words: ecosystem management, natural disturbance emulation, boreal forest, partial cut, structural retention, growth response, windthrow, post-harvest mortality

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A Decision Support System for Scheduling Partial Harvesting in Aquaculture

Decision Support Systems in Agriculture, Food and the Environment - Advances in Environmental Engineering and Green Technologies ◽

10.4018/978-1-61520-881-4.ch018 ◽

2011 ◽

pp. 406-419 ◽

Cited By ~ 2

Author(s):

Run Yu ◽

PingSun Leung ◽

Lotus E. Kam ◽

Paul Bienfang

Keyword(s):

Decision Support ◽

Decision Support System ◽

Support System ◽

Production Cycle ◽

Complex Nature ◽

Shrimp Culture ◽

Partial Harvest ◽

Partial Harvesting ◽

Intensive Aquaculture

The implementation of partial harvesting for intensive aquaculture is a difficult undertaking for the aqua-farmers, due to the complex nature of tracking the effects of reducing density on growth, survival and eventually on productivity and profitability. In this chapter, we describe the partial harvesting decision support system (PHDSS) developed by Kam et al. (2008). The PHDSS is designed to assist aqua-farmers in determining the best harvesting strategy for a production cycle. Potential harvesting strategies include both partial harvest and single-batch harvest. The chapter navigates the readers through the system, using shrimp culture as a case study.

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