scholarly journals Effects of Selective Forest Harvesting on Organic Matter Inputs and Accumulation in Headwater Streams

2004 ◽  
Vol 21 (1) ◽  
pp. 19-30 ◽  
Author(s):  
David P. Kreutzweiser ◽  
Scott S. Capell ◽  
Frederick D. Beall
Keyword(s):  
Organic Matter ◽  
Headwater Streams ◽  
Canopy Cover ◽  
Basal Area ◽  
Experimental Period ◽  
Forest Harvesting ◽  
Riparian Buffers ◽  
Water Yield ◽  
Buffer Strips ◽  
Selective Harvesting

Abstract Organic matter inputs and accumulation were measured in streams of low-order forest watersheds across a gradient of selective harvesting with no protective riparian buffers assigned. Comparisons were made among sites in selection-cut (average 29% basal area removal), shelterwood-cut (average 42% basal area removal), diameter limit-cut (average 89% basal area removal), and undisturbed tolerant hardwood catchments. The diameter limit harvest was an intentionally high-disturbance treatment and is not a normal silvicultural prescription for tolerant hardwoods in Ontario. Time trend analyses were conducted to examine differences among sites over a pre- and postharvest experimental period. Selection-based harvesting at up to 42% basal area removal with no riparian buffers did not significantly alter average over-stream canopy cover, leaf litter and other organic matter inputs, benthic particulate organic matter accumulation, or woody debris abundance. Harvesting impacts on over-stream canopy cover and organic matter inputs appeared to be minimized by natural crown architecture (overlap in crowns of over-stream trees, residual mid-crown canopy) and by careful logging practices including retention of many immediate streamside trees (within a few meters of the stream channel) and avoidance of felling directly into the streams. Dissolved organic matter fluxes increased slightly for 1 year after harvest and were associated with increased water yield. At the diameter limit harvesting intensity (about 89% basal area removal), significant effects on organic matter inputs and accumulation in streams were detected. The results indicate that selective harvesting of hardwood forests at up to about 42% basal area removal can be conducted without causing significant reductions in organic matter inputs and accumulation in headwater streams, even without prescribed streamside buffer strips.

Stream temperature responses to partial-harvest logging in riparian buffers of boreal mixedwood forest watersheds

2009 ◽  
Vol 39 (3) ◽  
pp. 497-506 ◽  
Author(s):  
David P. Kreutzweiser ◽  
Scott S. Capell ◽  
Stephen B. Holmes
Keyword(s):  
Canopy Cover ◽  
Basal Area ◽  
Riparian Buffers ◽  
Daily Maximum ◽  
Partial Harvest ◽  
Forest Watersheds ◽  
Boreal Mixedwood Forest ◽  
Maximum Temperatures ◽  
Forest Streams ◽  
Temperature Responses

As part of a larger study to examine the operational feasibility, ecological benefits, and environmental impacts of partial-harvest logging in riparian buffers along boreal mixedwood forest streams, we determined the effects on summer stream temperatures. Three logged study reaches were compared with three reference reaches over two prelogging and two postlogging summers. Partial-harvest logging resulted in an average removal of 10%, 20%, and 28% of the basal area from riparian buffers at the three logged sites. At the two more intensively logged sites, there were small (<10%) reductions in canopy cover (P = 0.024) and no significant changes in light at stream surfaces (P > 0.18). There were no measurable impacts on stream temperatures at two of the three logged sites. At the most intensively logged site, daily maximum temperatures were significantly higher (∼4 °C) for about 6 weeks in the first summer after logging than in prelogging years or at the reference sites (P < 0.001). Temperature increases were attributed to a logging-induced temporary disruption of cool water inputs from ground disturbance in a lateral-input seep area. Our results indicate that partial-harvest logging in riparian buffers of boreal mixedwood forest streams can sustain effective canopy cover and mitigate logging-induced water temperature increases.

Fine sediment deposition in streams after selective forest harvesting without riparian buffers

2001 ◽  
Vol 31 (12) ◽  
pp. 2134-2142 ◽  
Author(s):  
David P Kreutzweiser ◽  
Scott S Capell
Keyword(s):  
Sediment Accumulation ◽  
Road Construction ◽  
Forest Harvesting ◽  
Fine Sediment ◽  
Riparian Buffers ◽  
Sediment Deposition ◽  
Buffer Zones ◽  
Selective Harvesting ◽  
The Road ◽  
Canopy Removal

Fine sediment accumulation was measured in streams in low-order forest watersheds across a gradient of selective harvesting with no protective riparian buffers. Comparisons were made among sites in selection-cut (40% canopy removal), shelterwood-cut (50% canopy removal), diameter limit cut (about 85% canopy removal), and undisturbed tolerant hardwood catchments. These were further compared with a headwater stream catchment not harvested but affected by logging road activities. The greatest increases in fine inorganic sediment occurred at the road-improvement site with mean bedload estimates more than 4000 times higher than pre-manipulation values. Sediment bedload was still significantly elevated 2 years after the road-improvement activities. Significant increases (up to 1900 times the pre-harvest average) in inorganic sediment also occurred at the highly disturbed diameter-limit site as a result of heavy ground disturbance and channeled flowpaths from skidder activity in riparian areas. Similar increases were detected at the selection-cut site but were attributable to secondary road construction in the runoff area. In the shelterwood harvest area, where logging roads were not a factor, no measurable increases in sediment deposition were detected. There was little indication that harvesting activities at any site affected the organic fraction or the particle size distribution of fine sediments. The results of this study suggest that riparian buffer zones may not be necessary for selective harvesting in hardwood forests at up to 50% removal, at least in terms of reducing sediment inputs.

scholarly journals Adjudicating Perspectives on Forest Structure: How Do Airborne, Terrestrial, and Mobile Lidar-Derived Estimates Compare?

2021 ◽  
Vol 13 (12) ◽  
pp. 2297
Author(s):  
Jonathon J. Donager ◽  
Andrew J. Sánchez Meador ◽  
Ryan C. Blackburn
Keyword(s):  
Ponderosa Pine ◽  
Laser Scanning ◽  
Canopy Cover ◽  
Basal Area ◽  
Tree Height ◽  
Absolute Error ◽  
Forest Monitoring ◽  
Individual Tree ◽  
Structural Configurations ◽  
Individual Trees

Applications of lidar in ecosystem conservation and management continue to expand as technology has rapidly evolved. An accounting of relative accuracy and errors among lidar platforms within a range of forest types and structural configurations was needed. Within a ponderosa pine forest in northern Arizona, we compare vegetation attributes at the tree-, plot-, and stand-scales derived from three lidar platforms: fixed-wing airborne (ALS), fixed-location terrestrial (TLS), and hand-held mobile laser scanning (MLS). We present a methodology to segment individual trees from TLS and MLS datasets, incorporating eigen-value and density metrics to locate trees, then assigning point returns to trees using a graph-theory shortest-path approach. Overall, we found MLS consistently provided more accurate structural metrics at the tree- (e.g., mean absolute error for DBH in cm was 4.8, 5.0, and 9.1 for MLS, TLS and ALS, respectively) and plot-scale (e.g., R2 for field observed and lidar-derived basal area, m2 ha−1, was 0.986, 0.974, and 0.851 for MLS, TLS, and ALS, respectively) as compared to ALS and TLS. While TLS data produced estimates similar to MLS, attributes derived from TLS often underpredicted structural values due to occlusion. Additionally, ALS data provided accurate estimates of tree height for larger trees, yet consistently missed and underpredicted small trees (≤35 cm). MLS produced accurate estimates of canopy cover and landscape metrics up to 50 m from plot center. TLS tended to underpredict both canopy cover and patch metrics with constant bias due to occlusion. Taking full advantage of minimal occlusion effects, MLS data consistently provided the best individual tree and plot-based metrics, with ALS providing the best estimates for volume, biomass, and canopy cover. Overall, we found MLS data logistically simple, quickly acquirable, and accurate for small area inventories, assessments, and monitoring activities. We suggest further work exploring the active use of MLS for forest monitoring and inventory.

Effect of age, abomasal cannulation and rumen catheterization on intake and site of digestion by early-weaned lambs

1990 ◽  
Vol 114 (1) ◽  
pp. 49-54 ◽  
Author(s):  
G. J. Cruickshank ◽  
D. P. Poppi ◽  
A. R. Sykes ◽  
A. S. Familton
Keyword(s):  
Organic Matter ◽  
Live Weight ◽  
Experimental Period ◽  
Nutrient Digestion ◽  
Digestible Organic Matter ◽  
Outflow Rate ◽  
Ram Lambs ◽  
Effect Of Age ◽  
Cumulative Intake

SUMMARYThe voluntary food intake, in vivo digestibility and site of nutrient digestion was measured in 12 Polled Dorset ram lambs, from 6 to 24 weeks of age, offered clover hay. Lambs were weaned at 6 weeks of age. Six were fitted with a permanent T-shaped cannula in the abomasum and a temporary rumen catheter during the periods of digesta flow measurement.Surgical modification of lambs did not influence intake (g/kg live weight (W) per day), in vivo digestibility or marker retention time in the rumen. However, intact lambs grew significantly faster than cannulated lambs (139 v. 109g/day, P < 0·05) apparently because of an overall higher cumulative intake over the whole experimental period rather than any change in efficiency of use of nutrients or maintenance requirement.Relative to live weight, intake increased rapidly until c. 10 weeks of age and remained relatively constant at c. 37 g DM/kg W per day for the remainder of the experiment. Age had no effect on in vivo digestibility of organic matter (OM) or neutral detergent fibre (NDF) (average 0·69).The proportion of digestible organic matter apparently digested in the rumen (DOMADR) decreased from 0·63 to 0·47 between 8 and 24 weeks of age whilst intake between these measurement periods increased. Nonammonia N (NAN) flow past the abomasum was similar at all ages in relation to digestible organic matter intake (55·1 g NAN/kg DOMI) but was higher at 16 and 24 weeks of age than at 8 and 12 weeks of age, respectively, in relation to organic matter apparently digested in the rumen (OMADR) (116 and 85 g NAN/kg OMADR, respectively, P < 0·05).Fractional outflow rate of digesta markers from the rumen, when estimated from abomasal digesta, was significantly higher than when estimated from faeces (103Ru-p 0·121 v. 0·09; 51Cr-EDTA 0·169 v. 0·111/h; P > 0·05).It was concluded that cannulation did not affect intake and digestion characteristics in these young lambs. The changes in the site of nutrient digestion as the animals aged may have been due to agerelated changes in digestive function but appeared to be associated with the increase in intake that occurred between measurement periods of the cannulated lambs.

scholarly journals Sink or link? The bacterial role in benthic carbon cycling in the Arabian Sea's oxygen minimum zone

2013 ◽  
Vol 10 (11) ◽  
pp. 6879-6891 ◽  
Author(s):  
L. Pozzato ◽  
D. Van Oevelen ◽  
L. Moodley ◽  
K. Soetaert ◽  
J. J. Middelburg
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Particulate Organic Matter ◽  
Experimental Period ◽  
Oxygen Minimum Zone ◽  
Trophic Levels ◽  
Isotope Tracer ◽  
Oxygen Conditions ◽  
Minimum Zone ◽  
Oxygen Minimum

Abstract. The bacterial loop, the consumption of dissolved organic matter (DOM) by bacteria and subsequent transfer of bacterial carbon to higher trophic levels, plays a prominent role in pelagic food webs. However, its role in sedimentary ecosystems is not well documented. Here we present the results of isotope tracer experiments performed under in situ oxygen conditions in sediments from inside and outside the Arabian Sea's oxygen minimum zone (OMZ) to study the importance of the microbial loop in this setting. Particulate organic matter, added as phytodetritus, was processed by bacteria, protozoa and metazoans, while dissolved organic matter was processed only by bacteria and there was very little, if any, transfer to higher trophic levels within the 7 day experimental period. This lack of significant transfer of bacterial-derived carbon to metazoan consumers indicates that the bacterial loop is rather inefficient, in sediments both inside and outside the OMZ. Moreover, metazoans directly consumed labile particulate organic matter resources and thus competed with bacteria for phytodetritus.

scholarly journals Regional diversity of complex dissolved organic matter across forested hemiboreal headwater streams

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Jeffrey A. Hawkes ◽  
Nikola Radoman ◽  
Jonas Bergquist ◽  
Marcus B. Wallin ◽  
Lars J. Tranvik ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Headwater Streams ◽  
Regional Diversity

scholarly journals A comparative study of assessing organic matter decomposition between composting and vermicomposting process

2021 ◽  
Vol 6 (4) ◽  
pp. 768-776
Author(s):  
MZ Rahman ◽  
AKMA Kabir ◽  
MA Hashem ◽  
SMA Islam ◽  
MR Haque ◽  
...  
Keyword(s):  
Organic Matter ◽  
Crude Protein ◽  
Degradation Rate ◽  
Experimental Period ◽  
Ash Content ◽  
Cattle Manure ◽  
Crude Fiber ◽  
Treatment Groups ◽  
Fiber Degradation ◽  
Typical Temperature

The aim of the study was to compare the efficiency of organic matter degradation between composting and vermicomposting as well as the possibility of making compost and vermicompost using cattle manure. The experiment was conducted with two treatments, where one was conventional composting (T1) and another was vermicomposting (T2) from cattle manure. The sample from composted materials was collected at 0, 20, 40 and 60th day of experiment. Parameter studied were dry matter (DM), crude fiber (CF), crude protein (CP), ether extract (EE), ash content of the samples as well as pH and temperature change during the experimental period. Results found that a significant higher DM (P<0.01) was found in T1 compared to T2. The CF degradation rate was significantly higher (P<0.01) in T2 compared to T1 group. The CP content also found significantly higher (P<0.05) in T2 compared to T1 group. There were no significant differences in EE and ash content as well as pH between the treatment groups. A typical temperature curve was found in T1 during active composting phase but the temperature was more or less same in T2 during the whole experimental period. From the experiment, it was found that crude fiber degradation rate is faster and CP content was higher in the T2 compared to T1 that might be indicated that vermicomposting is more beneficial than composting. Asian J. Med. Biol. Res. December 2020, 6(4): 768-776

scholarly journals The Sediment Selectivity of Perinereis aibuhitensis Larvae: Active or Passive?

2021 ◽  
Vol 8 ◽  
Author(s):  
Jinghui Fang ◽  
Wei He ◽  
Shan Meng ◽  
Zengjie Jiang ◽  
Jianguang Fang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Natural Habitat ◽  
Organic Matter Content ◽  
Experimental Period ◽  
Matter Content ◽  
Active Selection ◽  
Sediment Types ◽  
Significant Difference ◽  
Perinereis Aibuhitensis ◽  
Sampling Times

The selectivity of Perinereis aibuhitensis larvae on different sediment types was studied using an experimental behavioral device in the lab. There were six types of sediment with different organic matter content: 2.19, 2.30, 2.86, 3.25, 3.51, and 5.52%. The results indicated significant differences in the six treatments’ organic matter content (p &lt; 0.05). When the P. aibuhitensis larvae initially attached to the sediment, the larvae’s density showed no significant difference among the six treatments. The density of larvae decreased gradually during the experimental period. It increased with the increasing organic matter content in sediment at every sampling time, but there was no significant difference (p &gt; 0.05). The larvae’s specific growth rate in the first month was significantly higher than those in the second and third months (p &lt; 0.05). The mortality showed no significance at different sediments in equal sampling times, but the mortality was lower in high organic matter content sediments. This study showed that the P. aibuhitensis larvae did not make an active selection; random selection happened when initially attached to the sediment with different organic matter contents. Higher organic matter content in the sediment was more conducive to larvae survival, and the organic matter content is the limitation factor on the mortality and the density. The different densities in the natural habitat of P. aibuhitensis might occur due to the passive selection by the environment.

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