scholarly journals Responses of Ground-Dwelling Invertebrates to Gap Formation and Accumulation of Woody Debris from Invasive Species, Wind, and Salvage Logging

Forests ◽  
2017 ◽  
Vol 8 (5) ◽  
pp. 174 ◽  
Author(s):  
◽  

Natural and anthropogenic disturbances alter canopy structure, understory vegetation, amount of woody debris, and the litter and soil layers in forest ecosystems. These environmental changes impact forest communities, including ground-dwelling invertebrates that are key regulators of ecosystem processes. Variation in frequency, intensity, duration, and spatial scale of disturbances affect the magnitude of these environmental changes and how forest communities and ecosystems are impacted over time. We propose conceptual models that describe the dynamic temporal effects of disturbance caused by invasive insects, wind, and salvage logging on canopy gap formation and accumulation of coarse woody debris (CWD), and their impacts on ground-dwelling invertebrate communities. In the context of this framework, predictions are generated and their implications for ground-dwelling invertebrate communities are discussed.

Insects ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 61 ◽  
Author(s):  
Kayla Perry ◽  
Daniel Herms

In forest ecosystems, natural and anthropogenic disturbances alter canopy structure, understory vegetation, amount of woody debris, and the properties of litter and soil layers. The magnitude of these environmental changes is context-dependent and determined by the properties of the disturbance, such as the frequency, intensity, duration, and extent. Therefore, disturbances can dynamically impact forest communities over time, including populations of ground-dwelling invertebrates that regulate key ecosystem processes. We propose conceptual models that describe the dynamic temporal effects of canopy gap formation and coarse woody debris accumulation following disturbances caused by invasive insects, wind, and salvage logging, and their impacts on ground-dwelling invertebrate communities. Within this framework, predictions are generated, literature on ground-dwelling invertebrate communities is synthesized, and pertinent knowledge gaps identified.


2021 ◽  
Vol 18 (6) ◽  
pp. 1405-1423
Author(s):  
Dariusz Strzyżowski ◽  
Elżbieta Gorczyca ◽  
Kazimierz Krzemień ◽  
Mirosław Żelazny

AbstractStrong wind events frequently result in creating large areas of windthrow, which causes abrupt environmental changes. Bare soil surfaces within pits and root plates potentially expose soil to erosion. Absence of forest may alter the dynamics of water circulation. In this study we attempt to answer the question of whether extensive windthrows influence the magnitude of geomorphic processes in 6 small second- to third-order catchments with area ranging from 0.09 km2 to 0.8 km2. Three of the catchments were significantly affected by a windthrow which occurred in December 2013 in the Polish part of the Tatra Mountains, and the other three catchments were mostly forested and served as control catchments. We mapped the pits created by the windthrow and the linear scars created by salvage logging operations in search of any signs of erosion within them. We also mapped all post-windthrow landslides created in the windthrow-affected catchments. The impact of the windthrow on the fluvial system was investigated by measuring a set of channel characteristics and determining bedload transport intensity using painted tracers in all the windthrow-affected and control catchments. Both pits and linear scars created by harvesting tend to become overgrown by vegetation in the first several years after the windthrow. The only signs of erosion were observed in 10% of the pits located on convergent slopes. During the period from the windthrow event in 2013 until 2019, 5 very small (total area <100 m2) shallow landslides were created. The mean distance of bedload transport was similar (t-test, p=0.05) in most of the windthrow-affected and control catchments. The mapping of channels revealed many cases of root plates fallen into a channel and pits created near a channel. A significant amount of woody debris delivered into the channels influenced the activity of fluvial processes by creating alternating zones of erosion and accumulation.


Forests ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 42
Author(s):  
Yan Wang ◽  
Zhongyue Li ◽  
Zhengquan Wang ◽  
Jiacun Gu

Absorptive and transport fine roots (diameter ≤ 2 mm) differ greatly in anatomy, morphology, and physiology, as well as their responses to environmental changes. However, it is still not well understood how their functional traits and biomass repartition respond to resource variability associated with increasing soil depth. Herein, we sampled the first five order roots of three hardwoods, i.e., Juglans mandshurica Maxim., Fraxinus mandshurica Rupr., and Phellodendron amurense Rupr. at surface (0–10 cm) and subsurface (20–30 cm) soil layers, respectively, and measured root biomass, anatomy, morphology, chemistry, and physiology at the branch-order level. Based on the anatomical characteristics, absorptive and transport fine roots were identified within each order, and their amounts and functional trait plasticity to soil depth were examined. The results showed that across soil layers, the first three order roots were mainly absorptive roots, while the fourth- and fifth-order roots were transport ones. From surface to subsurface soil layers, both the number and biomass proportion of absorptive fine roots decreased but those of transport fine roots increased. Transport fine root traits were more plastic to soil depth than absorptive ones, especially for the conduit-related traits. Absorptive fine roots in surface soil generally had stronger potential for resource acquisition than those in deeper soil, as indicated by their longer specific root length and greater root branching density. In comparison, transport fine roots in deeper soil were generally enhanced in their transportation function, with wider stele and higher hydraulic conductivity. Our findings suggest that functional specialization via multi-trait plasticity and coordination in both absorptive and transport fine roots along the soil depth would benefit the efficient soil resource exploitation of trees in forest ecosystems.


2019 ◽  
Vol 65 (No. 10) ◽  
pp. 408-422
Author(s):  
Vahid Etemad ◽  
Mohsen Javanmiri pour ◽  
Zeinab Foladi

In a natural forest, phases of different dynamics are gradually replaced to create sustainability in the stands. Coarse woody debris is among the most significant structural elements of natural stands that perform an influential position in the identification of dynamic phases. Therefore, the focus of this study is on dead wood conditioning as one of the major structural components in determining the various dynamic phases in the northern forests of Iran as part of the temperate forests. For this study, compartment 326 of Gorazbon District was considered as one of the control parcels of Kheyroud Forest. In this parcel, 25 one-hectare sample plots were selected as permanent plots for a long-term forest structure and succession studies. The coarse woody debris by 100% sampling method was measured. The results showed that there are 8 main phases in this area (gap formation, understorey initiation, stem exclusion, volume accumulation, volume degradation, multiple, lighting, old-growth). The extensive forest area (52%) is located in the understorey initiation and stem exclusion phases. The results also showed that the total average volume of snags and logs was 41.5 m<sup>3</sup>·ha<sup>–1</sup>. Furthermore, the mean dead wood volume in decay classes 1, 2, 3 and 4 was 10.33, 12.22, 9.15 and 83.9 m<sup>3</sup>·ha<sup>–1</sup>, respectively. The average frequency of dead trees in the diameter classes smaller than 25 cm, 25–50 cm and in the diameter class more than 50 cm is 25.79, 6.93, and 4.88. The significance analysis results obtained by ANOVA test showed that there is a significant difference between volume, snag and log stock and the shape of dead wood in various dynamic phases. Therefore, in general, dead wood in the forest differs according to habitat, evolutionary stage (dynamic phases), standing volume and species diversity of the tree species.


2013 ◽  
Vol 43 (12) ◽  
pp. 1203-1206 ◽  
Author(s):  
Andrew J. Larson

Falling canopy debris causes injury and mortality of tree seedlings and understory plants in a wide variety of forests. Canopy structure and dynamics differ between young and old-growth forests: old forests are taller and have more aboveground biomass and greater annual mortality of bole biomass. I predicted that risk of damage caused by debris fall in the understory is greater in old-growth forests than in young forests. I tested this prediction by tracking for 1 year the fates of artificial seedlings placed in young (stand age 31 to 61 years) and old-growth (stand age circa 500 years) Pseudotsuga–Tsuga forests. The risk of physical damage caused by debris fall in old-growth forests was significantly greater than in young forests (P = 0.001). Seedling models were damaged by falling debris at a rate of 4.4%·year−1 and 0.8%·year−1 in old-growth and young forests, respectively. More seedling models were damaged by fallen coarse woody debris in old-growth forests than in young forests, although this trend was not significant (P = 0.134). Approximately 25% of seedling models in both young and old-growth forests were damaged by something other than fallen canopy debris, most likely snow accumulation.


Sign in / Sign up

Export Citation Format

Share Document