Structural Complexity and Ecosystem Functions in a Natural Mixed Forest under a Single-Tree Selection Silviculture

Abstract Managing northern hardwood forests using high-frequency, low-intensity regimes, such as single-tree selection, favors shade-tolerant species and can reduce tree species diversity. Management decisions among family forest owners (FFO) can collectively affect species and structural diversity within northern hardwood forests at regional scales. We surveyed FFOs in the Western Upper Peninsula of Michigan to understand likely future use of three silvicultural treatments—single-tree selection, shelterwood, and clearcut. Our results indicate that FFOs were most likely to implement single-tree selection and least likely to implement clearcut within the next 10 years. According to logistic regression, prior use of a treatment and perceived financial benefits significantly increased the odds for likely use for all three treatments. Having received professional forestry assistance increased likely use of single-tree selection but decreased likely use of shelterwood. We discuss these results within the context of species diversity among northern hardwood forests throughout the region.

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Global patterns and climatic controls of forest structural complexity

Nature Communications ◽

10.1038/s41467-020-20767-z ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Martin Ehbrecht ◽

Dominik Seidel ◽

Peter Annighöfer ◽

Holger Kreft ◽

Michael Köhler ◽

...

Keyword(s):

Forest Structure ◽

Laser Scanning ◽

Structural Complexity ◽

Terrestrial Laser Scanning ◽

Ecosystem Functions ◽

The Earth ◽

Precipitation Seasonality ◽

Latitudinal Patterns ◽

Global Patterns ◽

Primary Forests

AbstractThe complexity of forest structures plays a crucial role in regulating forest ecosystem functions and strongly influences biodiversity. Yet, knowledge of the global patterns and determinants of forest structural complexity remains scarce. Using a stand structural complexity index based on terrestrial laser scanning, we quantify the structural complexity of boreal, temperate, subtropical and tropical primary forests. We find that the global variation of forest structural complexity is largely explained by annual precipitation and precipitation seasonality (R² = 0.89). Using the structural complexity of primary forests as benchmark, we model the potential structural complexity across biomes and present a global map of the potential structural complexity of the earth´s forest ecoregions. Our analyses reveal distinct latitudinal patterns of forest structure and show that hotspots of high structural complexity coincide with hotspots of plant diversity. Considering the mechanistic underpinnings of forest structural complexity, our results suggest spatially contrasting changes of forest structure with climate change within and across biomes.

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Quantifying Understory Complexity in Unmanaged Forests Using TLS and Identifying Some of Its Major Drivers

Remote Sensing ◽

10.3390/rs13081513 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1513

Author(s):

Dominik Seidel ◽

Peter Annighöfer ◽

Christian Ammer ◽

Martin Ehbrecht ◽

Katharina Willim ◽

...

Keyword(s):

Laser Scanning ◽

Structural Equation Models ◽

Light Availability ◽

Structural Complexity ◽

Basal Area ◽

Ecosystem Functions ◽

Canopy Openness ◽

Seasonal Precipitation ◽

Wide Range ◽

Precipitation And Temperature

The structural complexity of the understory layer of forests or shrub layer vegetation in open shrublands affects many ecosystem functions and services provided by these ecosystems. We investigated how the basal area of the overstory layer, annual and seasonal precipitation, annual mean temperature, as well as light availability affect the structural complexity of the understory layer along a gradient from closed forests to open shrubland with only scattered trees. Using terrestrial laser scanning data and the understory complexity index (UCI), we measured the structural complexity of sites across a wide range of precipitation and temperature, also covering a gradient in light availability and basal area. We found significant relationships between the UCI and tree basal area as well as canopy openness. Structural equation models (SEMs) confirmed significant direct effects of seasonal precipitation on the UCI without mediation through basal area or canopy openness. However, annual precipitation and temperature effects on the UCI are mediated through canopy openness and basal area, respectively. Understory complexity is, despite clear dependencies on the available light and overall stand density, significantly and directly driven by climatic parameters, particularly the amount of precipitation during the driest month.

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Fifty years of partial harvesting in a mixed mesophytic forest: composition and productivity

Canadian Journal of Forest Research ◽

10.1139/x03-262 ◽

2004 ◽

Vol 34 (5) ◽

pp. 985-997 ◽

Cited By ~ 82

Author(s):

Thomas M Schuler

Keyword(s):

Forest Management ◽

Sugar Maple ◽

Acer Rubrum ◽

Timber Harvesting ◽

Red Oak ◽

Northern Red Oak ◽

Single Tree ◽

Periodic Growth ◽

Mesophytic Forest ◽

Single Tree Selection

Long-term silvicultural trials contribute to sustainable forest management by providing a better scientific understanding of how forest ecosystems respond to periodic timber harvesting. In this study, species composition, diversity, and net periodic growth of tree species in a mixed mesophytic forest in the central Appalachians were evaluated after about a half century of management. Three partial cutting practices on 18 research compartments and on 3 unmanaged reference compartments were evaluated (19512001) on 280 ha. Single-tree selection, diameter-limit harvesting, and timber harvesting in 0.162-ha patches were assessed on three northern red oak site index50 (SI) classes: 24, 21, and 18. ShannonWeiner's diversity index (H′) declined from the first (19511959) to last (19872001) measurements and was related to both SI (P = 0.004) and treatment (P = 0.009). Sugar maple (Acer saccharum Marsh.) and red maple (Acer rubrum L.) were the two most abundant species in recent years (19872001); in contrast, in initial inventories (19511959), northern red oak (Quercus rubra L.) and chestnut oak (Quercus prinus L.) were most abundant. Net periodic annual increment (PAI) of merchantable trees (DBH ≥12.7 cm) was related to both SI (P = 0.004) and treatment (P = 0.003). Mean PAI ranged from 4.6 m3·ha1·year1 for single-tree selection to 2.5 m3·ha1·year1 for unmanaged reference areas across all SI classes. The decline of oak species suggests that only intensive and specific forest management focused on maintaining oak species can obtain historical levels of diversity.

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Brown Creeper (Certhia americana) demographic response to hardwood forests managed under the selection system

Canadian Journal of Forest Research ◽

10.1139/cjfr-2015-0112 ◽

2016 ◽

Vol 46 (4) ◽

pp. 499-507 ◽

Cited By ~ 2

Author(s):

Daniel M. Geleynse ◽

Erica Nol ◽

Dawn M. Burke ◽

Ken A. Elliott

Keyword(s):

Site Selection ◽

Group Selection ◽

Nest Survival ◽

Forested Wetlands ◽

Timing Of Breeding ◽

Yellow Birch ◽

Single Tree ◽

Single Tree Selection ◽

Foraging Site ◽

Brown Creeper

The Brown Creeper (Certhia americana Bonaparte, 1838) has been identified as one of the most sensitive passerines to partial forest harvest in North America. The effect of selection logging on Brown Creeper density, nest timing, nest survival, and nest and foraging site selection was examined in five silviculture treatments (intensive group selection, typical group selection, old single-tree selection, recent single-tree selection, and control forests) of Algonquin Provincial Park, Canada. As Brown Creeper nests under the bark of large, decaying trees, we hypothesized that Brown Creeper density, timing of breeding, nest survival, and nest and foraging site selection would be negatively affected by silviculture through the removal of large, decaying trees as part of providing safe conditions for loggers. We monitored 101 nests of Brown Creeper during the 2010 and 2011 breeding seasons, mapped territories to estimate density, and conducted foraging surveys. Brown Creeper density was reduced by about 42% in logged stands compared with control stands. Despite that, silviculture did not significantly alter timing of breeding or nest survival. However, the loss of large trees through partial harvesting meant that Brown Creeper nested closer to adjacent, small forested wetlands and often in balsam fir (Abies balsamea (L.) Mill.) in treated stands. In control stands, Brown Creeper nested further from forested wetlands, disproportionately in greater numbers in upland hardwoods, and preferentially in the bark of snags of yellow birch (Betula alleghaniensis Britton). The change in the species of tree used for nesting and the general forest type as a result of logging also resulted in consequences for the selection of foraging substrates. To maintain higher densities of Brown Creeper in logged stands in Algonquin Park, we recommend retaining larger diameter yellow birch, both snags and live trees, preferably within strategically located uncut reserves based on habitat supply planning, that maintains patches roughly the size of Brown Creeper territories (10 ha).

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