Forest floor dynamics in a chronosequence of hardwood stands in central Nova Scotia

1986 ◽  
Vol 16 (2) ◽  
pp. 293-302 ◽  
Author(s):  
E. S. Wallace ◽  
B. Freedman
Keyword(s):  
Weight Loss ◽  
Nova Scotia ◽  
Forest Floor ◽  
Stand Age ◽  
Total Production ◽  
Clear Cutting ◽  
Nitrate N ◽  
Ammonium N ◽  
Field Samples ◽  
Mature Stands

A postclear-cutting chronosequence of hardwood stands in Nova Scotia was examined for patterns of forest floor weight, concentration of selected nutrients, rate of potential insitu litter decomposition (litterbags), and potential lab ammonification and nitrification. Some evidence was found that the forest floor experiences weight loss following clear-cutting. However, the large weight losses and clear pattern of recovery described by others for New Hampshire hardwood chronosequences were not observed. The lack of close agreement may have been a result of intra- and inter-stand variation in forest floor weight in our study. This spatial variation was greater than any effect as a result of clear-cutting. There was no significant relationship between insitu weight loss of leaves or twigs with stand age. No clear-cutting effect was observed in the laboratory for potential ammonification, which occurred readily in all stands (three clear-cuttings, three mature stands). Limed materials produced significantly more mineralized N (nitrate N + ammonium N) than did unlimed materials. Concentrations of ammonium N in F and H horizon field material were significantly higher on clear-cuttings than in mature stands. However, since this measurement reflects net rather than total production, it is not evidence that higher rates of ammonification occurred on clear-cuttings. Potential nitrification was not an important process in F and H horizon materials at their natural pH. Nitrification occurred readily in limed materials, but there were no significant differences among different aged stands. Concentrations of nitrate N in field F and H horizon material were low for all stands, with a mean of 9 ± 7 ppm (n = 350). However, in 7% of field samples, nitrate N ≥ 15 ppm was found; in 2%, ≥30 ppm was found.

Nitrogen-retention capacity in a fertilized forest after clear-cutting — the effect of forest-floor vegetation

2015 ◽  
Vol 45 (1) ◽  
pp. 130-134 ◽  
Author(s):  
Per-Ola Hedwall ◽  
Johan Bergh ◽  
Annika Nordin
Keyword(s):  
Vegetation Cover ◽  
Forest Floor ◽  
Nitrogen Retention ◽  
Tree Seedling ◽  
Retention Capacity ◽  
N Retention ◽  
Clear Cutting ◽  
Nitrate N ◽  
Ammonium N ◽  
Forest Floor Vegetation

Forest fertilization with nitrogen (N) has several benefits to society such as increased wood production and carbon sequestration. There are, however, concerns about N leakage, particularly following clear-cutting. The forest-floor vegetation may increase the N retention of forest ecosystems; however, very few studies have quantified the amount of vegetation required. We studied the relationship between vegetation cover and risk of N leakage, estimated by the amounts of ammonium-N and nitrate-N retained on ion-exchange capsules in the soil, during 4 years following the clear-cutting and harvesting of logging residues in a previously fertilized forest in southern Sweden. Previous fertilization increased the amount of nitrate-N captured on the capsules, whereas the amount of ammonium-N decreased. The vascular vegetation cover increased from almost zero to approximately 25% independent of fertilization. The amount of ammonium-N and nitrate-N retained on the capsules was already reduced by 50%–75% at 20% vegetation cover, and by 30%–40% cover, it approached zero, independent of the number of years since clear-cutting. The vegetation may impede tree-seedling establishment, implying a trade-off between seedling growth and N-retention capacity. However, our results indicate that maximum N retention may be achieved at a relatively low vegetation cover, which could be accomplished with less intrusive scarification methods than currently used.

Vegetation development in a hardwood-forest chronosequence in Nova Scotia

1994 ◽  
Vol 24 (2) ◽  
pp. 260-271 ◽  
Author(s):  
M. Crowell ◽  
B. Freedman
Keyword(s):  
Nova Scotia ◽  
Aboveground Biomass ◽  
Vascular Plants ◽  
Tree Bark ◽  
Ground Vegetation ◽  
Vegetation Development ◽  
Clear Cutting ◽  
Vigorous Growth ◽  
Mature Stands ◽  
Rate Of Accumulation

Vegetation and aboveground biomass and nutrient capital (N, P, K, Ca, and Mg) were examined in a 22-stand, 75-year chronosequence within an angiosperm-dominated forest in Nova Scotia. Stands 20 years old and younger originated with clear-cutting, whereas older stands originated with wildfire. Early successional, ruderal species of vascular plants were prominent for ca. 5 years after clear-cutting, but they occurred as a part of a diverse, species-rich community dominated by more-tolerant species, many of which survived the disturbance of clear-cutting. The rate of accumulation of aboveground biomass averaged 2.2 t•ha−1•year−1 during the first 11 years after clear-cutting, 4.7 t•ha−1•year−1 between 11 and 30 years, and then decreased to 1.5 t•ha−1•year−1 between 30 and 75 years. Foliage biomass recovered to a quantity typical of mature stands within only 3–5 years of disturbance, as a result of the vigorous growth of both ground vegetation and stump sprouts of certain tree species. The patterns of accumulation of N, P, K, and Mg were similar to that of biomass, except that initially their relative rates of accumulation were faster because of the large proportion of nutrient-rich foliage in young stands. The accumulation of Ca was relatively slower, because of its large concentration in tree bark, a tissue whose proportion in the aboveground biomass reached a maximum much later than did foliage.

Organic matter and nitrogen content of the forest floor in even-aged northern hardwoods

1984 ◽  
Vol 14 (6) ◽  
pp. 763-767 ◽  
Author(s):  
C. Anthony Federer
Keyword(s):  
Organic Matter ◽  
Nitrogen Content ◽  
Bulk Density ◽  
Forest Floor ◽  
Mineral Soil ◽  
Organic Content ◽  
Stand Age ◽  
Clear Cutting ◽  
Mature Forest ◽  
Forest Floors

Organic content of the forest floor decreases for several years after clear-cutting, and then slowly recovers. Thickness, bulk density, organic matter, and nitrogen content of forest floors were measured for 13 northern hardwood stands in the White Mountains of New Hampshire. Stands ranged from 1 to about 100 years in age. Forest-floor thickness varied significantly with stand age, but bulk density, organic fraction, and nitrogen fraction were independent of age. Total organic content of the forest floor agreed very well with data from Covington's (W. W. Covington 1981. Ecology, 62: 41–48) study of the same area. Both studies indicated that mature forest floors have about 80 Mg organic matter•ha−1 and 1.9 Mg nitrogen•ha−1. Within 10 or 15 years after cutting, the organic matter content of the floor decreases to 50 Mg•ha−1, and its nitrogen content to 1.1 Mg•ha−1. The question whether the decrease is rapid and the minimum broad and flat, or if the decrease is gradual and the minimum sharp, cannot be answered. The subsequent increase to levels reached in mature forest requires about 50 years. Some of the initial decrease in organic matter and nitrogen content of the forest floor may be caused by organic decomposition and nitrogen leaching, but mechanical and chemical mixing of floor into mineral soil, during and after the harvest operation, may also be important. The difference is vital with respect to maintenance of long-term productivity.

scholarly journals Correction to: Modeling the temporal distribution of water, ammonium-N, and nitrate-N in the root zone of wheat using HYDRUS-2D under conservation agriculture

2020 ◽  
Vol 27 (2) ◽  
pp. 2217-2225 ◽  
Author(s):  
Poomadathil Mohammed Shafeeq ◽  
Pramila Aggarwal ◽  
Prameela Krishnan ◽  
Vikas Rai ◽  
Pragati Pramanik ◽  
...  
Keyword(s):  
Root Zone ◽  
Temporal Distribution ◽  
Conservation Agriculture ◽  
Nitrate N ◽  
Ammonium N

Nitrogen storage and availability during stand development in a New Zealand Nothofagus forest

2002 ◽  
Vol 32 (2) ◽  
pp. 344-352 ◽  
Author(s):  
P W Clinton ◽  
R B Allen ◽  
M R Davis
Keyword(s):  
New Zealand ◽  
Forest Floor ◽  
Woody Debris ◽  
Mineral Soil ◽  
Stand Development ◽  
N Availability ◽  
Net N Mineralization ◽  
Nitrogen Storage ◽  
Nothofagus Forest ◽  
Mature Stands

Stemwood production, N pools, and N availability were determined in even-aged (10, 25, 120, and >150-year-old) stands of a monospecific mountain beech (Nothofagus solandri var. cliffortioides (Hook. f.) Poole) forest in New Zealand recovering from catastrophic canopy disturbance brought about by windthrow. Nitrogen was redistributed among stemwood biomass, coarse woody debris (CWD), the forest floor, and mineral soil following disturbance. The quantity of N in stemwood biomass increased from less than 1 kg/ha in seedling stands (10 years old) to ca. 500 kg/ha in pole stands (120 years old), but decreased in mature stands (>150 years old). In contrast, the quantity of N stored in CWD declined rapidly with stand development. Although the mass of N stored in the forest floor was greatest in the pole stands and least in the mature stands, N availability in the forest floor did not vary greatly with stand development. The mass of N in the mineral soil (0–100 mm depth) was also similar for all stands. Foliar N concentrations, net N mineralization, and mineralizable N in the mineral soil (0–100 mm depth) showed similar patterns with stage of stand development, and indicated that N availability was greater in sapling (25 years old) and mature stands than in seedling and pole stands. We conclude that declining productivity in older stands is associated more with reductions in cation availability, especially calcium, than N availability.

scholarly journals Soil Organic Carbon Stocks in Afforested Agricultural Land in Lithuanian Hemiboreal Forest Zone

Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1562
Author(s):  
Iveta Varnagirytė-Kabašinskienė ◽  
Povilas Žemaitis ◽  
Kęstutis Armolaitis ◽  
Vidas Stakėnas ◽  
Gintautas Urbaitis
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Forest Floor ◽  
Agricultural Land ◽  
Forest Stand ◽  
Stand Age ◽  
Soc Stock ◽  
The Mean ◽  
Soc Stocks ◽  
Topsoil Layer

In the context of the specificity of soil organic carbon (SOC) storage in afforested land, nutrient-poor Arenosols and nutrient-rich Luvisols after afforestation with coniferous and deciduous tree species were studied in comparison to the same soils of croplands and grasslands. This study analysed the changes in SOC stock up to 30 years after afforestation of agricultural land in Lithuania, representing the cool temperate moist climate region of Europe. The SOC stocks were evaluated by applying the paired-site design. The mean mass and SOC stocks of the forest floor in afforested Arenosols increased more than in Luvisols. Almost twice as much forest floor mass was observed in coniferous than in deciduous stands 2–3 decades after afforestation. The mean bulk density of fine (<2 mm) soil in the 0–30 cm mineral topsoil layer of croplands was higher than in afforested sites and grasslands. The clear decreasing trend in mean bulk density due to forest stand age with the lowest values in the 21–30-year-old stands was found in afforested Luvisols. In contrast, the SOC concentrations in the 0–30 cm mineral topsoil layer, especially in Luvisols afforested with coniferous species, showed an increasing trend due to the influence of stand age. The mean SOC values in the 0–30 cm mineral topsoil layer of Arenosols and Luvisols during the 30 years after afforestation did not significantly differ from the adjacent croplands or grasslands. The mean SOC stock slightly increased with the forest stand age in Luvisols; however, the highest mean SOC stock was detected in the grasslands. In the Arenosols, there was higher SOC accumulation in the forest floor with increasing stand age than in the Luvisols, while the proportion of SOC stocks in mineral topsoil layers was similar and more comparable to grasslands. These findings suggest encouragement of afforestation of former agricultural land under the current climate and soil characteristics in the region, but the conversion of perennial grasslands to forest land should be done with caution.

scholarly journals STUDIES ON WHITE PINE BLISTER RUST IN NOVA SCOTIA

1953 ◽  
Vol 29 (3) ◽  
pp. 267-272 ◽  
Author(s):  
W. K. McGinn ◽  
A. G. Davidson
Keyword(s):  
Nova Scotia ◽  
Control Measure ◽  
Systematic Search ◽  
White Pine Blister Rust ◽  
White Pine ◽  
Clear Cutting ◽  
Blister Rust ◽  
Pine Regeneration ◽  
Show Evidence ◽  
Cutting Operation

Studies were undertaken in Nova Scotia to determine (i) the effect of different cutting practices on the establishment of a RIBES population and of white pine regeneration, (ii) whether blister rust is a major factor in retarding the establishment of white pine regeneration, and (iii) the feasibility and cost of RIBES eradication as a direct control measure against blister rust. No relationship was found to exist between RIBES establishment and the degree of cutting. Uncut softwood stands, where white pine is the predominant species, show evidence of producing a future pine crop. Forest types supporting white pine appear to offer the best opportunities for pine reproduction where a clear-cutting operation has given the stand maximum opening. Results of the present study to date do not show that blister rust is a major factor in retarding the establishment of white pine regeneration. To eradicate RIBES from the study area by a complete systematic search required 1 man-hour per acre. Because of the small number of RIBES plants found and of the tendency for them to occur consistently in moist, low-lying habitats, a complete systematic search for these plants appears to be unnecessary. It is suggested that one man, trained to recognize RIBES and their probable location, could cover large forest tracts with a minimum of time expended in searching localities unlikely to support these plants.

Soil inorganic-N and nitrate leaching on organic farms

1993 ◽  
Vol 120 (3) ◽  
pp. 361-369 ◽  
Author(s):  
C. A. Watson ◽  
S. M. Fowlerf ◽  
D. Wilman
Keyword(s):  
Nitrate Leaching ◽  
Arable Soils ◽  
Surface Layers ◽  
Inorganic N ◽  
Organic Farms ◽  
Soil Layers ◽  
Crop Uptake ◽  
Nitrate N ◽  
Ammonium N ◽  
Soil Inorganic N

SUMMARYOn two organic farms, nitrate-N and ammonium-N in the surface layers of the soil of representative fields were recorded for 2 years. Nitrate-N was also determined in different soil layers down to 120 cm at the beginning, middle and end of two winters and at intervals after ploughing three fields, to seek evidence of leaching.Nitrate-N and ammonium-N were both consistently low in the surface layers of fields in ley. Nitrate-N accumulated in arable soils on some occasions when there was little or no crop uptake of N, after ploughing, and after very heavy applications of manure.There was some evidence of nitrate leaching in all five fields which were deep-sampled. In four cases, the loss by leaching appeared to be < 25 kg N/ha per winter. In the other case, in which a 4-year ley was ploughed on 5 October, the loss by leaching appeared to be c. 70 kg N/ha. Ploughing in winter, rather than early autumn, might have reduced the nitrate leached, but the drilling of the next crop might have been delayed.The nitrate concentration of water draining from recently ploughed sandy soil in Shropshire was high, but it would have been diluted by water draining from unploughed fields.

Effects on understory biomass and forage 8–10 years after precommercial thinning of Sitka spruce – western hemlock stands in southeast Alaska

2020 ◽  
Vol 50 (2) ◽  
pp. 215-225
Author(s):  
Justin S. Crotteau ◽  
Annelise Z. Rue-Johns ◽  
Jeffrey C. Barnard
Keyword(s):  
Forest Type ◽  
Sitka Spruce ◽  
Picea Sitchensis ◽  
Wildlife Habitat ◽  
Western Hemlock ◽  
Stand Age ◽  
Southeast Alaska ◽  
Precommercial Thinning ◽  
Clear Cutting ◽  
Understory Biomass

In southeast Alaska, United States, multiple-use forest management objectives include both timber production and wildlife habitat. Following stand-replacing disturbances such as clear-cutting, Sitka spruce (Picea sitchensis (Bong.) Carrière) and western hemlock (Tsuga heterophylla (Raf.) Sarg.) naturally regenerate and competitively dominate resources, excluding understory biomass and biodiversity. Thinning may mitigate the effects of canopy closure and permit understory development, but evidence of the effect on understories 8–10 years after thinning is lacking. We report results 4–5 and 8–10 years after thinning experiments on the Tongass National Forest to demonstrate the effects of precommercial thinning (thinned versus control), stand age (15–25, 25–35, and 35–50 years), and weather on understory dynamics and Sitka black-tailed deer (Odocoileus hemionus sitkensis Merriam, 1898) forage availability. Stand density negatively affected understory biomass, whereas temperature and precipitation positively interacted to increase biomass. Thinning had an enduring effect on understories, with biomass at least twice as great in thinned versus unthinned stands through year 10. We identified compositional differences from thinning as stand age class increased. Deer forage responded similarly to biomass, but thinning-induced differences faded with increased winter snowfall scenarios, especially in older stands. This study aids the understanding of stand overstory and understory development following silvicultural treatments in the coastal temperate rain forest of Alaska and suggests management implications and applications for balancing objectives throughout the forest type.

scholarly journals Cultivation of CNPA G3 sesame irrigated with saline water and fertilized with nitrate-N and ammonium-N

2017 ◽  
Vol 21 (1) ◽  
pp. 14-20 ◽  
Author(s):  
Geovani S. de Lima ◽  
Adaan S. Dias ◽  
Lauriane A. dos A. Soares ◽  
Hans R. Gheyi ◽  
José P. Camara Neto ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Water Use Efficiency ◽  
Water Use ◽  
Water Consumption ◽  
Saline Water ◽  
Early Maturation ◽  
Nitrate N ◽  
Ammonium N ◽  
Use Efficiency ◽  
Delayed Flowering

ABSTRACT The study aimed to evaluate the effects of irrigation with saline water and fertilization with nitrate (NO3--N) and ammonium (NH4+-N) ratios on growth, flowering, water consumption and water use efficiency of the sesame cv. CNPA G3. The treatments were distributed in randomized blocks in a 5 x 5 factorial with three replicates, referring to five levels of electrical conductivity of the irrigation water - ECw (0.6, 1.2, 1.8, 2.4 and 3.0 dS m-1) and nitrate (NO3--N) and ammonium (NH4+-N) (200/0, 150/50, 100/100, 50/150, 0/200 mg kg-1) ratios. Irrigation with saline water above 0.6 dS m-1 inhibited the growth, delayed flowering and promoted early maturation of capsules of sesame, cv. CNPA G3. The proportion of 0/200 mg kg-1 of NO3--N/NH4+-N promoted the greatest increase relative to stem diameter and height of sesame plants. Water consumption decreases with increasing ECw and was significantly lower in plants fertilized with the proportion of 0/200 of NO3--N/NH4+-N. The interaction between ECw levels and ammonium/nitrate proportions significantly affect water use efficiency, and the highest value was obtained with ECw of 0.6 dS m-1 and fertilization with 150:50 mg kg-1 of NO3--N and NH4+-N.

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