Woody Debris and Its Contribution to Pool Formation in a Coastal Stream 50 Years after Logging

1988 ◽  
Vol 45 (12) ◽  
pp. 2080-2086 ◽  
Author(s):  
C. W. Andrus ◽  
B. A. Long ◽  
H. A. Froehlich
Keyword(s):  
Crucial Role ◽  
Riparian Forest ◽  
Woody Debris ◽  
Stream Channels ◽  
Riparian Trees ◽  
Study Results ◽  
Pool Formation

Large quantities of woody debris persisted 50 yr after logging and fire in stream channels of a small coastal Oregon watershed. Debris from the current stand represented only 14% of total debris volume and 8% of debris volume responsible for creating pools. The greatest number of pools were located in downstream sections of the watershed where gradient was reduced, discharge was increased, and streambed material was finer. Seventy percent of pools with a volume greater than 1.0 m3 were associated with woody debris in the channel. Composition of the current riparian forest varied with topography. Alder stands dominated moist terrace sites adjacent to channels, whereas slopes contained a mixture of alder and conifer. Study results indicate that riparian trees must be left to grow longer than 50 yr to ensure that an adequate, long-term supply of woody debris is available to stream channels. Debris from previous stands plays a crucial role in the interim and should not be removed from stream channels.

Long-term monitoring of the recruitment and dynamics of large wood in Kamienica Stream, Polish Carpathians

2020 ◽  
Author(s):  
Paweł Mikuś ◽  
Bartłomiej Wyżga
Keyword(s):  
Fourth Order ◽  
Flood Hazard ◽  
Riparian Forest ◽  
Woody Debris ◽  
Large Wood ◽  
Order Stream ◽  
Riparian Trees ◽  
Metal Plates ◽  
Polish Carpathians

<p>Quantifying delivery and mobility of large woody debris in small mountain streams requires long-term and repeatable observations, so far very scarcely described. Such observations have been conducted in the upper course of Kamienica Stream, Polish Western Carpathians, where a sample of 429 trees growing along three separated sections of  the stream was tagged with metal plates and monitored during 10 years. The monitoring of standing and fallen trees has been conducted a few times per year, especially after heavy rainfall and windstorms. In this period, 96 trees (22.4% of the tagged sample) were recruited to the channel during high-intensity meteorological and hydrological events, mostly as a result of bank erosion during floods and windthrow, with recent bark beetle infestation of the riparian forest considerably accelerating the turnover of riparian trees. Large wood inventory performed in 2012 in the second- to fourth-order stream reaches and of the 10 years-long monitoring of tagged trees indicated variable mobility of large wood along the upper course of the stream. Wood mobility was negligible in the second-order reach, very small in the third-order reach, and higher, but still limited in the fourth-order reach. 46 trees were subjected to transport during five significant floods, and mean lengths of displacement of the tagged trees were small, not exceeding 32 m in sections A and B, whereas in section C they were a few times longer. However, an advanced state of decay of most pieces leads to their disintegration during floods, rather than to distant transport, and thus large wood retained in the upper stream course within a national park does not constitute an important flood hazard to downstream, inhabited valley reaches.</p>

The dynamics of coarse woody debris in boreal Swedish forests are similar between stream channels and adjacent riparian forests

2006 ◽  
Vol 36 (5) ◽  
pp. 1139-1148 ◽  
Author(s):  
Niklas Dahlström ◽  
Christer Nilsson
Keyword(s):  
Tree Species ◽  
Coarse Woody Debris ◽  
Riparian Forest ◽  
Woody Debris ◽  
Riparian Forests ◽  
Stream Channels ◽  
Terrestrial Environment ◽  
Riparian Trees ◽  
Forest Sites ◽  
Coniferous Tree Species

Although numerous studies have focused on the dynamics of coarse woody debris (CWD) in boreal Fennoscandian forests, information on CWD in streams remains limited. To achieve a better understanding of CWD dynamics in streams we compared amounts and characteristics of CWD between streams and adjacent riparian forests in old-growth and managed forest sites, respectively. We also identified distances to the sources of CWD and evaluated these in relation to the lateral zonation of riparian trees. CWD volumes found in the stream channels were related to, but exceeded, the volumes found in the adjacent forest. In-channel volumes separated by species were better correlated with terrestrial volumes of CWD than with volumes of living trees. Tree species appeared to be zoned across the riparian zone, with slightly higher abundances of deciduous trees and lower abundances of Scots pine trees close to the stream. Similar to upland forests, riparian forests were dominated by coniferous tree species, mainly Norway spruce (Picea abies (L.) Karst.). These findings suggest large similarities in CWD input between streams and riparian forests and substantially slower decomposition rates in stream channels compared with those in riparian forest. The results provide an improved basis for creating reliable models of CWD supply and maintenance in streams based on knowledge of forest development and CWD dynamics in the terrestrial environment. Site productivity could potentially be used to predict CWD volumes in stream channels under pristine conditions.

Large woody debris characteristics and contributions to pool formation in forest streams of the Boreal Shield

2005 ◽  
Vol 35 (5) ◽  
pp. 1213-1223 ◽  
Author(s):  
David P Kreutzweiser ◽  
Kevin P Good ◽  
Trent M Sutton
Keyword(s):  
Woody Debris ◽  
Average Frequency ◽  
Large Woody Debris ◽  
Primary Input ◽  
Clear Cut ◽  
Mixedwood Forests ◽  
Riparian Trees ◽  
Boreal Shield ◽  
And Function ◽  
Pool Formation

The inputs, characteristics, and function of large woody debris (LWD) were assessed in 16 mid-order (average channel widths of 3–7 m), moderate-gradient (approx. 1%–5% channel slopes) streams in mixedwood forests of the Boreal Shield in Ontario. Three of the streams were adjacent to clearcuts, with the remainder in areas that have not been logged or recently (>70 years) burned. The average frequency (19.9 pieces·100 m–1) and size (mean diameter 16.7 cm) of LWD in these streams were less than reported in most other regions and forest types. Averaged across sites, input sources were undetermined for about 50% of the LWD owing to fluvial displacement from the points of origin. Natural mortality (24%) and windthrow (15%) were primary input sources of the remaining LWD. Windthrow was highly variable and mostly associated with nearby clear-cut logging. At the three sites near clearcuts, windthrow contributed 34%–62% of LWD in streams. In study reaches where active beaver colonies were observed, beaver-felled trees accounted for up to 47% of LWD inputs. The average frequency of debris dams (2.4 dams·100 m–1) was less than those reported from studies in other areas and was positively correlated with an index of bottom substrate size (r = 0.72). Less than 15% of the pools in these streams were formed or influenced by LWD. Most wood pieces appeared to be ineffective as pool-forming agents because of their relatively small size and instability. In these Boreal Shield forests, it appears that most riparian trees do not live long enough or grow to sufficient size to contribute functional LWD and influence stream morphology or pool formation.

The Effect and Extent of Railroad Tie Drives in Streams of Southeastern Wyoming

1994 ◽  
Vol 9 (4) ◽  
pp. 125-130 ◽  
Author(s):  
Michael K. Young ◽  
David Haire ◽  
Michael A. Bozek
Keyword(s):  
Coarse Woody Debris ◽  
Riparian Vegetation ◽  
Riparian Zone ◽  
Woody Debris ◽  
Channel Structure ◽  
National Forest ◽  
Stream Channel ◽  
Riparian Trees ◽  
Large Trees

Abstract Millions of railroad ties were floated (driven) down streams in southeastern Wyoming between 1868 and 1940. We identified 61 tie-driven streams in or near the Medicine Bow National Forest. We hypothesized that tie drives, and the stream clearing associated with driving, altered channel morphology and riparian vegetation. When comparing stream reaches of similar width and gradient, we found that tie-driven stream reaches contained less coarse woody debris and had significantly lower densities of large riparian trees than did unaffected reaches. Tie-driven reaches had lower channel complexity, a greater proportion of riffles, and fewer plunge and dammed pools than did unaffected reaches. We found significant relations among characteristics of the riparian trees, coarse woody debris, and stream channel structure. Recovery of the affected reaches may be contingent on the long-term increase in large trees in the riparian zone. West. J. Appl. For. 9(4):125-130.

scholarly journals Woody debris as a confounding factor in interpreting the width of spring-fed streams

2019 ◽  
Author(s):  
Dana Ariel Lapides ◽  
Michael Manga
Keyword(s):  
Woody Debris ◽  
Unit Length ◽  
Channel Morphology ◽  
Climate Data ◽  
Stream Channels ◽  
Stream Width ◽  
Order Of Magnitude ◽  
High Resolution Satellite Imagery ◽  
The Impact

Abstract. Spring-fed streams throughout volcanic regions of the western United States exhibit larger widths than runoff-fed streams with similar discharge. Due to the distinctive damped hydrograph of spring-fed streams, large woody debris is less mobile in spring-fed than runoff-fed stream channels. The consequent long residence time of wood in spring-fed streams allows wood to potentially have long-term impacts on channel morphology. We used high-resolution satellite imagery in combination with discharge and climate data from published reports and publicly available databases to investigate the relationship between discharge, woody debris length, and channel width in 38 spring-fed and 20 runoff-fed streams. We identify an order of magnitude more logjams than single logs per unit length present in runoff-fed streams as compared to spring-fed streams. Histograms of log orientation in spring-fed streams additionally confirm that single logs are immobile in the channel so that the impact of single logs on channel morphology could be pronounced in spring-fed streams. Based on these observed differences, we hypothesize that there should be a difference in channel morphology. We find that spring-fed streams in our study are about 2 times wider than runoff-fed streams with similar mean discharge. Additionally, a model for stream width in spring-fed streams based solely on length of wood is a better model than one derived from discharge or including both discharge and wood length. This study provides insights into controls on stream width in spring-fed streams by identifying a strong correlation between wood length and stream width and confirming that spring-fed streams are significantly wider than runoff-fed streams.

Health Literacy and Long-Term Care Needs among Thai Elderly in Rural Communities

2020 ◽  
Vol 103 (12) ◽  
pp. 1315-1324
Keyword(s):  
Depressive Symptom ◽  
Health Literacy ◽  
Rural Communities ◽  
Long Term Care ◽  
Health Knowledge ◽  
Elderly Persons ◽  
Care Needs ◽  
Term Care ◽  
Study Results

Background: Factors related to long-term care needs have been studied widely, but there is limited research about the influence of health literacy on long-term care needs among the elderly in rural communities where the social context and care environment are uniquely different. Objective: To examine factors influencing long-term care needs among Thai elderly in rural communities. Materials and Methods: The present study used the cross-sectional design. The study sample included 477 elderly persons, who were members of the communities in Nakhon Ratchasima Province. Multi-stage random sampling was used to select participants. They were interviewed using the demographic and health information questionnaire, the Thai Geriatric Depression Scale (TGDS), the health literacy scale of Thai adults and long-term care needs questionnaire. The selected factors examined as independent variables included some demographic factors, depressive symptom, and health literacy. Results: The present study results revealed significant positive relationships existing between long-term care needs with age and depressive symptom, while negative relationships between income and health literacy were reported. A hierarchical multiple regression analysis indicated that four of nine determinants of long-term care needs: age, depressive symptom, health knowledge and understanding, and ability managing their health condition significantly predicted long-term care needs at a level of 18% (R² adjusted=0.18, p<0.001). Conclusion: The present study results showed associations between personal and health literacy factors with long-term care needs. These findings prove that it is vitally important for healthcare professionals to consider the rural elderly’s mental health status and health literacy when providing care and planning treatment. Keywords: Health literacy, Long-term care needs, Rural community

scholarly journals A Holistic Framework for Evaluating Adaptation Approaches to Coastal Hazards and Sea Level Rise: A Case Study from Imperial Beach, California

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1324
Author(s):  
David Revell ◽  
Phil King ◽  
Jeff Giliam ◽  
Juliano Calil ◽  
Sarah Jenkins ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Public Trust ◽  
Adaptation Strategy ◽  
Public Benefits ◽  
Study Results ◽  
Local Risk ◽  
Over Time

Sea level rise increases community risks from erosion, wave flooding, and tides. Current management typically protects existing development and infrastructure with coastal armoring. These practices ignore long-term impacts to public trust coastal recreation and natural ecosystems. This adaptation framework models physical responses to the public beach and private upland for each adaptation strategy over time, linking physical changes in widths to damages, economic costs, and benefits from beach recreation and nature using low-lying Imperial Beach, California, as a case study. Available coastal hazard models identified community vulnerabilities, and local risk communication engagement prioritized five adaptation approaches—armoring, nourishment, living shorelines, groins, and managed retreat. This framework innovates using replacement cost as a proxy for ecosystem services normally not valued and examines a managed retreat policy approach using a public buyout and rent-back option. Specific methods and economic values used in the analysis need more research and innovation, but the framework provides a scalable methodology to guide coastal adaptation planning everywhere. Case study results suggest that coastal armoring provides the least public benefits over time. Living shoreline approaches show greater public benefits, while managed retreat, implemented sooner, provides the best long-term adaptation strategy to protect community identity and public trust resources.

scholarly journals French Firms and COVID-19: Do the Debt Status, Crisis Management System, and Monetary Policy Play a Role?

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mina Sami
Keyword(s):  
Monetary Policy ◽  
Stock Returns ◽  
Crisis Management ◽  
Management System ◽  
Daily Growth ◽  
Listed Firms ◽  
Study Results ◽  
Major Outbreak

Abstract This study has two main objectives: first, it assesses the effect of outbreak pandemic diseases on the French firms’ stock returns by considering the sector of activity as the main center of analysis. Second, it investigates the role of the crisis management system, firm debt strategy, and monetary policy in dealing with the adverse shocks of the major outbreak of the COVID-19. The study results can be summarized as follows: (1) the daily growth in COVID-19 cases and deaths are associated with lower stock returns of the listed firms, especially for the firms operating in the energy, industrial and health care sectors. In contrast, telecommunication and consumer sectors are not significantly affected. (2) The pandemic’s adverse effect is much more tolerant with the French firms with an efficient crisis management system and low long-term debt commitments than the firms that do not have such a system and engaged with long term debts. (3) Euribor rates and monetary policy are still playing an essential role during the pandemic period.

scholarly journals Reproductive Performance Following Hysteroscopic Surgery for Uterine Septum: Results from a Single Surgeon Data

2021 ◽  
Vol 10 (1) ◽  
pp. 130
Author(s):  
Ertan Saridogan ◽  
Mona Salman ◽  
Lerzan Sinem Direk ◽  
Ali Alchami
Keyword(s):  
Reproductive Performance ◽  
Observational Studies ◽  
Patient Characteristics ◽  
Reproductive Outcomes ◽  
Hysteroscopic Surgery ◽  
High Quality Evidence ◽  
Study Results ◽  
Significant Difference ◽  
Uterine Septum

Uterine septum can negatively affect reproductive outcomes in women. Based on evidence from retrospective observational studies, hysteroscopic incision has been considered a solution to improve reproductive performance, however there has been recent controversy on the need for surgery for uterine septum. High quality evidence from prospective studies is still lacking, and until it is available, experts are encouraged to publish their data. We are therefore presenting our data that involves analysis of the patient characteristics, surgical approach and long-term reproductive outcomes of women who received treatment for uterine septum under the care of a single surgeon. This includes all women (99) who underwent hysteroscopic surgery for uterine septum between January 2001 and December 2019. Of those 99 women treated for intrauterine septum who were trying to conceive, 91.4% (64/70) achieved pregnancy, 78.6% (55/70) had live births and 8.6% (6/70) had miscarriages. No statistically significant difference was found in the live birth rates when data was analyzed in subgroups based on age, reason for referral/aetiology and severity of pathology. Our study results support the view that surgical treatment of uterine septa is beneficial in improving reproductive outcomes.

scholarly journals Evaluating Machine Learning and Geostatistical Methods for Spatial Gap-filling of Monthly ESA CCI Soil Moisture in China

2021 ◽  
Vol 13 (14) ◽  
pp. 2848
Author(s):  
Hao Sun ◽  
Qian Xu
Keyword(s):  
Machine Learning ◽  
Soil Moisture ◽  
Water Resource Management ◽  
Large Scale ◽  
Gap Filling ◽  
Spatial Continuity ◽  
Study Results ◽  
Data Gaps

Obtaining large-scale, long-term, and spatial continuous soil moisture (SM) data is crucial for climate change, hydrology, and water resource management, etc. ESA CCI SM is such a large-scale and long-term SM (longer than 40 years until now). However, there exist data gaps, especially for the area of China, due to the limitations in remote sensing of SM such as complex topography, human-induced radio frequency interference (RFI), and vegetation disturbances, etc. The data gaps make the CCI SM data cannot achieve spatial continuity, which entails the study of gap-filling methods. In order to develop suitable methods to fill the gaps of CCI SM in the whole area of China, we compared typical Machine Learning (ML) methods, including Random Forest method (RF), Feedforward Neural Network method (FNN), and Generalized Linear Model (GLM) with a geostatistical method, i.e., Ordinary Kriging (OK) in this study. More than 30 years of passive–active combined CCI SM from 1982 to 2018 and other biophysical variables such as Normalized Difference Vegetation Index (NDVI), precipitation, air temperature, Digital Elevation Model (DEM), soil type, and in situ SM from International Soil Moisture Network (ISMN) were utilized in this study. Results indicated that: 1) the data gap of CCI SM is frequent in China, which is found not only in cold seasons and areas but also in warm seasons and areas. The ratio of gap pixel numbers to the whole pixel numbers can be greater than 80%, and its average is around 40%. 2) ML methods can fill the gaps of CCI SM all up. Among the ML methods, RF had the best performance in fitting the relationship between CCI SM and biophysical variables. 3) Over simulated gap areas, RF had a comparable performance with OK, and they outperformed the FNN and GLM methods greatly. 4) Over in situ SM networks, RF achieved better performance than the OK method. 5) We also explored various strategies for gap-filling CCI SM. Results demonstrated that the strategy of constructing a monthly model with one RF for simulating monthly average SM and another RF for simulating monthly SM disturbance achieved the best performance. Such strategy combining with the ML method such as the RF is suggested in this study for filling the gaps of CCI SM in China.

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