Communities of aquatic insects of old-growth and clearcut coastal headwater streams of varying flow persistence

2003 ◽  
Vol 33 (8) ◽  
pp. 1416-1432 ◽  
Author(s):  
Karen Price ◽  
Arlene Suski ◽  
Joanna McGarvie ◽  
Barbara Beasley ◽  
John S Richardson
Keyword(s):  
Aquatic Insects ◽  
Algal Biomass ◽  
Headwater Streams ◽  
Canopy Cover ◽  
Ephemeral Streams ◽  
Aquatic Communities ◽  
Old Growth ◽  
Organic Detritus ◽  
Temporary Streams ◽  
Old Growth Forest

Headwater streams, varying in flow persistence from ephemeral to intermittent to perennial, provide the tightest coupling between water and land, yet they often receive the least protection during forest management. We described communities of aquatic insects in perennial, intermittent, and ephemeral channels surrounded by old-growth forest and 4- to 8-year-old clearcuts in Clayoquot Sound, British Columbia, to determine whether temporary streams have unique aquatic communities and to examine the short-term impacts of harvesting. We measured flow persistence, stream size, canopy cover, organic detritus, and algal biomass in 19 streams. We sampled aquatic invertebrates with a combination of emergence cages and kicknet samples. Temporary and old-growth streams had more organic detritus and a higher abundance of shredders. Perennial and clearcut streams had a higher abundance of some algal grazers, but not higher algal biomass. Insect richness was similar in intermittent and perennial streams of each seral stage but lower in ephemeral streams. Intermittent streams contained four taxa not found in the other stream classes; perennial and ephemeral streams had none. Communities of aquatic insects differed between streams surrounded by clearcuts and old growth, and varied with continuity of flow.

scholarly journals Secondary disturbance following a deposit of volcanic tephra: A 30 year record from old-growth forest understory

2021 ◽  
Author(s):  
Donald B Zobel ◽  
Joseph A. Antos ◽  
Dylan Grey Fischer
Keyword(s):  
Vegetation Change ◽  
Forest Disturbance ◽  
Canopy Cover ◽  
Soil Disturbance ◽  
Tree Canopy ◽  
Forest Understory ◽  
Old Growth ◽  
Old Growth Forest ◽  
Volcanic Ejecta ◽  
Woody Litter

Forest disturbance is usually described by effects on trees, and small disturbances to forest understory are seldom studied. Nevertheless, effective analyses of succession need to consider both stand-replacing and subsequent “secondary” disturbances in both canopy and understory. We estimated characteristics of 13 types of secondary disturbance in old-growth forest understory, and of canopy cover, after the 1980 tephra (aerially transported volcanic ejecta) deposition from Mount St. Helens, Washington. We sampled 100 1-m2 plots at each of four sites for vegetation change and types of disturbance at ten times from 1980-2010; we sampled tree canopy above each plot in 1980 and 2016. The number of canopy gaps increased 23 % and mean gap dimension 68 % during 36 years, mostly from loss of Abies amabilis. Secondary disturbance in understory affected 1.4 % of stand area per year. The areas affected by soil disturbance and effects of woody litter were similar. Erosion, greater in deep than in shallow tephra, peaked in 1981, whereas most litter-caused disturbances increased after 2000. Less frequent litter-based disturbances covered greater area. Our results differ from conclusions about non-volcanic understory disturbances. Secondary disturbances are variable, need more study, and are likely to affect many other systems.

Tradable Disturbance Permits for Old-growth Forest Conservation: Experimental Evaluation of Implementation Options

2017 ◽  
Vol 7 (1-2) ◽  
pp. 73-107
Author(s):  
Orsolya Perger ◽  
Curtis Rollins ◽  
Marian Weber ◽  
Wiktor Adamowicz ◽  
Peter Boxall
Keyword(s):  
Experimental Evaluation ◽  
Forest Conservation ◽  
Old Growth ◽  
Old Growth Forest

Old-growth forest reserves in Slovenia: the past, present, and future

2012 ◽  
Vol 163 (6) ◽  
pp. 240-246 ◽  
Author(s):  
Thomas A. Nagel ◽  
Jurij Diaci ◽  
Dusan Rozenbergar ◽  
Tihomir Rugani ◽  
Dejan Firm
Keyword(s):  
Stand Structure ◽  
Growth Conditions ◽  
Ecosystem Functions ◽  
Future Research ◽  
Old Growth ◽  
Forest Reserves ◽  
The Past ◽  
Old Growth Forest ◽  
Forest Remnants ◽  
Basic Characteristics

Old-growth forest reserves in Slovenia: the past, present, and future Slovenia has a small number of old-growth forest remnants, as well as many forest reserves approaching old-growth conditions. In this paper, we describe some of the basic characteristics of these old-growth remnants and the history of their protection in Slovenia. We then trace the long-term development of research in these old-growth remnants, with a focus on methodological changes. We also review some of the recent findings from old-growth research in Slovenia and discuss future research needs. The conceptual understanding of how these forests work has slowly evolved, from thinking of them in terms of stable systems to more dynamic and unpredictable ones due to the influence of natural disturbances and indirect human influences. In accordance with this thinking, the methods used to study old-growth forests have changed from descriptions of stand structure to studies that address natural processes and ecosystem functions.

Old-growth forest carbon sinks overestimated

Nature ◽  
2021 ◽  
Vol 591 (7851) ◽  
pp. E21-E23
Author(s):  
Per Gundersen ◽  
Emil E. Thybring ◽  
Thomas Nord-Larsen ◽  
Lars Vesterdal ◽  
Knute J. Nadelhoffer ◽  
...  
Keyword(s):  
Forest Carbon ◽  
Carbon Sinks ◽  
Old Growth ◽  
Old Growth Forest

scholarly journals Effects of nitrogen and phosphorus additions on nitrous oxide emission in a nitrogen-rich and two nitrogen-limited tropical forests

2016 ◽  
Vol 13 (11) ◽  
pp. 3503-3517 ◽  
Author(s):  
Mianhai Zheng ◽  
Tao Zhang ◽  
Lei Liu ◽  
Weixing Zhu ◽  
Wei Zhang ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Tropical Forests ◽  
N2o Emission ◽  
N Deposition ◽  
Soil N ◽  
N Addition ◽  
Old Growth ◽  
Old Growth Forest ◽  
P Addition ◽  
Stimulation Of

Abstract. Nitrogen (N) deposition is generally considered to increase soil nitrous oxide (N2O) emission in N-rich forests. In many tropical forests, however, elevated N deposition has caused soil N enrichment and further phosphorus (P) deficiency, and the interaction of N and P to control soil N2O emission remains poorly understood, particularly in forests with different soil N status. In this study, we examined the effects of N and P additions on soil N2O emission in an N-rich old-growth forest and two N-limited younger forests (a mixed and a pine forest) in southern China to test the following hypotheses: (1) soil N2O emission is the highest in old-growth forest due to the N-rich soil; (2) N addition increases N2O emission more in the old-growth forest than in the two younger forests; (3) P addition decreases N2O emission more in the old-growth forest than in the two younger forests; and (4) P addition alleviates the stimulation of N2O emission by N addition. The following four treatments were established in each forest: Control, N addition (150 kg N ha−1 yr−1), P addition (150 kg P ha−1 yr−1), and NP addition (150 kg N ha−1 yr−1 plus 150 kg P ha−1 yr−1). From February 2007 to October 2009, monthly quantification of soil N2O emission was performed using static chamber and gas chromatography techniques. Mean N2O emission was shown to be significantly higher in the old-growth forest (13.9 ± 0.7 µg N2O-N m−2 h−1) than in the mixed (9.9 ± 0.4 µg N2O-N m−2 h−1) or pine (10.8 ± 0.5 µg N2O-N m−2 h−1) forests, with no significant difference between the latter two. N addition significantly increased N2O emission in the old-growth forest but not in the two younger forests. However, both P and NP addition had no significant effect on N2O emission in all three forests, suggesting that P addition alleviated the stimulation of N2O emission by N addition in the old-growth forest. Although P fertilization may alleviate the stimulated effects of atmospheric N deposition on N2O emission in N-rich forests, this effect may only occur under high N deposition and/or long-term P addition, and we suggest future investigations to definitively assess this management strategy and the importance of P in regulating N cycles from regional to global scales.

Geostatistically modeling stem size and increment in an old-growth forest

1994 ◽  
Vol 24 (7) ◽  
pp. 1354-1368 ◽  
Author(s):  
Franco Biondi ◽  
Donald E. Myers ◽  
Charles C. Avery
Keyword(s):  
Spatial Patterns ◽  
Growth Rates ◽  
Spatial Dependence ◽  
Basal Area ◽  
Tree Density ◽  
Individual Growth ◽  
Old Growth ◽  
Model Estimate ◽  
Stem Size ◽  
Old Growth Forest

Geostatistics provides tools to model, estimate, map, and eventually predict spatial patterns of tree size and growth. Variogram models and kriged maps were used to study spatial dependence of stem diameter (DBH), basal area (BA), and 10-year periodic basal area increment (BAI) in an old-growth forest stand. Temporal variation of spatial patterns was evaluated by fitting spatial stochastic models at 10-year intervals, from 1920 to 1990. The study area was a naturally seeded stand of southwestern ponderosa pine (Pinusponderosa Dougl. ex Laws. var. scopulorum) where total BA and tree density have steadily increased over the last decades. Our objective was to determine if increased stand density simply reduced individual growth rates or if it also altered spatial interactions among trees. Despite increased crowding, stem size maintained the same type of spatial dependence from 1920 to 1990. An isotropic Gaussian variogram was the model of choice to represent spatial dependence at all times. Stem size was spatially autocorrelated over distances no greater than 30 m, a measure of average patch diameter in this forest ecosystem. Because patch diameter remained constant through time, tree density increased by increasing the number of pine groups, not their horizontal dimension. Spatial dependence of stem size (DBH and BA) was always much greater and decreased less through time than that of stem increment (BAI). Spatial dependence of BAI was close to zero in the most recent decade, indicating that growth rates in 1980–1990 varied regardless of mutual tree position. Increased tree crowding corresponded not only to lower average and variance of individual growth rates, but also to reduced spatial dependence of BAI. Because growth variation was less affected by intertree distance with greater local crowding, prediction of individual growth rates benefits from information on horizontal stand structure only if tree density does not exceed threshold values. Simulation models and area estimates of tree performance in old-growth forests may be improved by including geostatistical components to summarize ecological spatial dependence.

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