Impact of clearcutting and slash burning on ectomycorrhizal associations of Douglas-fir seedlings

1984 ◽  
Vol 14 (1) ◽  
pp. 94-100 ◽  
Author(s):  
David P. Pilz ◽  
David A. Perry
Keyword(s):  
Douglas Fir ◽  
Root Tip ◽  
Root Tips ◽  
Clear Cut ◽  
Clear Cutting ◽  
Ectomycorrhizal Types ◽  
Different Types ◽  
Undisturbed Forest ◽  
Soil Origin ◽  
Slash Burning

The effect of clear-cutting, with and without slash burning, on ectomycorrhizal formation of Douglas-fir seedlings (Pseudotsugamenziesii (Mirb.) Franco var. menziesii) was studied in field and greenhouse bioassays. Twelve ectomycorrhizal types were found in three western Cascade Mountain sites on seedlings planted in soils exchanged among burned and unburned portions of clear-cuts and undisturbed forest. Rhizopogon sp. and an unidentified brown type consistently formed at least two-thirds of the ectomycorrhizal root tips. Regardless of soil origin, more ectomycorrhizae formed in clear-cuts than in undisturbed forest (primarily due to more brown mycorrhizae). Soil origin did not affect total numbers of ectomycorrhizae; however, more different types formed in undisturbed forest soils than in clear-cut soils, irrespective of aboveground environment. More nonmycorrhizal tips occurred in clear-cut soils. Seedlings grown in the same soils formed the same proportions of Rhizopogon and brown types in field and greenhouse, but not the same proportions of less common ectomycorrhizal types. Soil pasteurization increased root-tip numbers. Inoculated soils (1 part nonpasteurized: 9 parts pasteurized) produced as many ectomycorrhizae as nonpasteurized field soils and generally fewer tips than pasteurized soils. Formation of major (but not minor) ectomycorrhizal types on all sites was influenced more by aboveground changes that accompany clear-cutting and site preparation than by alterations in soil chemistry or biology.

Phosphorus forms and related soil chemistry of Podzolic soils on northern Vancouver Island. II. The effects of clear-cutting and burning

2000 ◽  
Vol 30 (11) ◽  
pp. 1726-1741 ◽  
Author(s):  
Barbara J Cade-Menun ◽  
Shannon M Berch ◽  
Caroline M Preston ◽  
L M Lavkulich
Keyword(s):  
Organic Matter ◽  
Vancouver Island ◽  
Available P ◽  
Resonance Spectroscopy ◽  
Inorganic P ◽  
Clear Cut ◽  
Podzolic Soils ◽  
Clear Cutting ◽  
Slash Burning

When cedar-hemlock (CH) forests of northern Vancouver Island are clear-cut and replanted, growth of replanted trees is often poor. This growth check can be overcome with nitrogen (N) and phosphorus (P) fertilization, suggesting that it may be because of deficiencies of these elements. A widely used site-preparation tool in these forests is slash burning. Because fire is known to alter nutrient cycling in forests, this burning may be contributing to the problem of poor seedling growth. Thus, the objective of this study was to compare P in forest floor and soils from clear-cut CH stands 10 years, 5 years, and immediately after burning to P concentrations and forms in undisturbed old growth CH stands. Analytical methods included extraction and digestion procedures, fractionation and 31P nuclear magnetic resonance spectroscopy. Soon after burning, an "ashbed effect" was noted, with increased pH and higher concentrations of available P in surface soil horizons. Available P concentrations and pH returned to preburn levels within 10 years. However, destruction of organic matter appeared to disrupt illuviation processes throughout the soil profile, producing long-term changes in organic matter, organic P, and organically complexed Fe and Al in lower mineral horizons. Total P concentrations were unchanged, but there was a shift from organic to inorganic P forms and changes in P forms with time at depth in the profile. These changes in P distribution and movement in the soil may contribute to the growth check observed in these forests.

The effect of soil disturbance on growth and ectomycorrhizae of Douglas-fir and western hemlock seedlings: a greenhouse bioassay

1982 ◽  
Vol 12 (2) ◽  
pp. 343-353 ◽  
Author(s):  
M. Meyer Schoenberger ◽  
D. A. Perry
Keyword(s):  
Soil Disturbance ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Root Tips ◽  
Old Growth ◽  
Clear Cut ◽  
Old Growth Forest ◽  
Litter Leachate ◽  
Oregon Cascades ◽  
Tip Formation

In a greenhouse bioassay of soils from the central Oregon Cascades, Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seedlings had the most total and ectomycorrhizal root tips when grown in soil from an unburned clear-cut and the least when grown in soil from (i) a 20-year-old plantation that had been clear-cut and burned in the late 1950's and (ii) one old-growth forest. Tip formation was intermediate in soil from a second old-growth forest, a recently burned clear-cut, and a 40-year-old natural burn. Root weights followed the same trend, but top weights did not differ among the various soils. Ectomycorrhizal and total root tips of western hemlock (Tsugaheterophylla (Raf.) Sarg.) were lowest in soils from the plantation and recently burned clear-cut. Unlike Douglas-fir, western hemlock's tip production was not greater in the unburned clear-cut than in the old-growth forest soils. In this species, both top and root weights varied according to soil, with the largest seedlings produced in soil from the unburned clear-cut. With both species, there was a significant interaction between ectomycorrhizal type and soil type. Cenococcumgeophilum Fr. predominated on western hemlock and was reduced in soils from the burned clear-cut and plantation. In comparison with the mean for all soils, ectomycorrhizal types that predominated on Douglas-fir were enhanced in the unburned clear-cut soil and reduced in one old-growth soil, an effect apparently related to litter leachate.

Root chemistry of Douglas-fir seedlings grown under different nitrogen and potassium regimes

1998 ◽  
Vol 28 (10) ◽  
pp. 1566-1573 ◽  
Author(s):  
Terry M Shaw ◽  
James A Moore ◽  
John D Marshall
Keyword(s):  
Pseudotsuga Menziesii ◽  
Dry Matter ◽  
Douglas Fir ◽  
Root Tip ◽  
Root Tips ◽  
Seedling Biomass ◽  
High K ◽  
Root Chemistry ◽  
Low K ◽  
Root Collar

Root chemistry and biomass allocation of Douglas-fir (Pseudotsuga menziesii var. glauca (Bessn.) Franco) seedlings under optimal and deficient levels of nitrogen (N) and potassium (K) were studied. Seedlings receiving high-N treatments were significantly larger and allocated more dry matter to their stems and less to their roots than those receiving the low-N treatments. The K treatments did not significantly affect total seedling biomass or root/shoot ratios. Root tip starch concentrations were significantly higher and root tip sugar concentrations were lower in plants receiving the low-N treatments. Seedlings receiving the high-N, low-K treatment had significantly lower concentrations of phenolics and tannins and lower ratios of these compounds to sugars in the root tips than seedlings receiving the high-K treatments. Samples taken from two locations on the root system show that concentrations of phenolics, tannins, sugars, and starches were substantially higher in the root collar than in the root tips. Because of lower within tissue variation, we recommend sampling at root tips to better detect treatment differences. This study shows that N levels affect starch concentrations in the roots, while K levels affect root phenolic and tannin concentrations. Possible relationships between low root phenolic and tannin concentrations and lessened resistance of Douglas-fir to root disease are discussed.

Ultrastructure of modified root-tip cells in Ficus carica, induced by the ectoparasitic nematode Xiphinema index

1980 ◽  
Vol 41 (1) ◽  
pp. 193-208
Author(s):  
U. Wyss ◽  
H. Lehmann ◽  
R. Jank-Ladwig
Keyword(s):  
Egg Production ◽  
Root Apex ◽  
Hypersensitive Reaction ◽  
Ficus Carica ◽  
Root Tip ◽  
Root Tips ◽  
Agar Culture ◽  
Binucleate Cells ◽  
Clear Cut ◽  
Xiphinema Index

The migratory ectoparasitic root nematode Xiphinema index, added to Ficus carica seedlings in sterile agar culture, fed exclusively on the tips of the roots. As a response the tips started to swell and became transformed into terminal galls as long as feeding was continued. When the cytology of swollen root-tips was examined 24 h after the first nematode attack, necrotic cells, scattered singly or in small groups within the root apex, were found in ultrathin sections. These cells, whose protoplasts showed features of a hypersensitive reaction, were most probably those fed upon by nematodes. Each necrotic cell was surrounded by several enlarged, mostly binucleate cells with dense cytoplasm. One day later the binucleate cells were multinucleate, containing 4 or even 8 nuclei. The clear-cut demarcation between necrotic and modified cells indicated that only the stimulus for the induction of modified cells but not the stimulus for cell necrosis passed into neighbouring cells. Root-tip galls that provided the appropriate food for egg production in nematodes contained greatly enlarged multinucleate cells between necrotic cells. The modified cells showed features of high metabolic activities, expressed in nuclear and nucleolar hypertrophy, invagination of the nuclear envelope, increased cytoplasmic density, abundance of mitochondria, plastids and rough endoplasmic reticulum. Wall ingrowths, typical of transfer cells, were rare and if present occurred only adjacent to necrotic cells. In older modified cells new cell plates, surrounded by phragmoplasts, were formed.

Histochemical Examination of Invertase Activities in the Growing Tip of the Plant Root

2017 ◽  
Vol 10 (1) ◽  
pp. 35-45
Author(s):  
N.F. Lunkova ◽  
N.A. Burmistrova ◽  
M.S. Krasavina
Keyword(s):  
Plant Root ◽  
Invertase Activity ◽  
Root Tip ◽  
Elongation Zone ◽  
Root Tips ◽  
Phloem Unloading ◽  
Meristem Cell ◽  
Transition To Elongation ◽  
Different Tissues

Background:A growing part of the root is one of the most active sinks for sucrose coming from source leaves through the phloem. In the root, sucrose is unloaded from conducting bundles and is distributed among the surrounding cells. To be involved in the metabolism, sucrose should disintegrate into hexoses by means of degrading enzymes.Aims:The aim of this research was to explore the possibility of the involvement of one such enzymes, invertase, in phloem unloading as well as distribution of its activity in the functionally different tissues of the plant root tips.Method:To estimate the enzyme activities in root tissues, we applied two techniques: the histochemical method using nitro blue tetrazolium. The localization of phloem unloading was studied with carboxyfluorescein, a fluorescent marker for symplastic transport.Results:Invertase activity was not detected in the apical part of the meristem. It appeared only between the basal part of this zone and the beginning of the elongation zone. There is the root phloem unloading in that area. Invertase activity increased with increasing the distance from the root tip and reached the highest values in the region of cell transition to elongation and in the elongation zone. The activities of the enzyme varied in different tissues of the same zone and sometimes in the neighboring cells of the same tissue. Biochemical determination of invertase activity was made in the maize root segments coincident to the zones of meristem, cell elongation and differentiation. The results of both methods of determination of invertase activity were in agreement.Conclusion:It was concluded that phloem unloading correlated with invertase activity, possibly because of the activation of invertase by unloaded sucrose. Invertase is one of the factors involved in the processes preparing the cells for their transition to elongation because the concentration of osmotically active hexoses increases after cleavage of sucrose, that stimulates water entry into the cells, which is necessary for elongation growth.

scholarly journals Threat or Corrective? Assessing the Impact of Populist Parties in Government on the Qualities of Democracy: A 19-Country Comparison

2021 ◽  
pp. 1-21
Author(s):  
Davide Vittori
Keyword(s):  
Negative Impact ◽  
Quality Of Democracy ◽  
Clear Cut ◽  
Liberal Democratic ◽  
Country Comparison ◽  
Democratic Regimes ◽  
Different Types ◽  
The Impact

Abstract Scholars have long debated whether populism harms or improves the quality of democracy. This article contributes to this debate by focusing on the impact of populist parties in government. In particular, it inquires: (1) whether populists in government are more likely than non-populists to negatively affect the quality of democracies; (2) whether the role of populists in government matters; and (3) which type of populism is expected to negatively affect the quality of liberal-democratic regimes. The results find strong evidence that the role of populists in government affects several qualities of democracy. While robust, the findings related to (2) are less clear-cut than those pertaining to (1). Finally, regardless of their role in government, different types of populism have different impacts on the qualities of democracy. The results show that exclusionary populist parties in government tend to have more of a negative impact than other forms of populism.

scholarly journals Effect of earthworms on mycorrhization, root morphology and biomass of silver fir seedlings inoculated with black summer truffle (Tuber aestivum Vittad.)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tina Unuk Nahberger ◽  
Gian Maria Niccolò Benucci ◽  
Hojka Kraigher ◽  
Tine Grebenc
Keyword(s):  
Root System ◽  
Root Biomass ◽  
Fine Root ◽  
Abies Alba ◽  
Fine Root Biomass ◽  
Root Tip ◽  
Silver Fir ◽  
Tuber Aestivum ◽  
Root Tips ◽  
Root Parameters

AbstractSpecies of the genus Tuber have gained a lot of attention in recent decades due to their aromatic hypogenous fruitbodies, which can bring high prices on the market. The tendency in truffle production is to infect oak, hazel, beech, etc. in greenhouse conditions. We aimed to show whether silver fir (Abies alba Mill.) can be an appropriate host partner for commercial mycorrhization with truffles, and how earthworms in the inoculation substrate would affect the mycorrhization dynamics. Silver fir seedlings inoculated with Tuber. aestivum were analyzed for root system parameters and mycorrhization, how earthworms affect the bare root system, and if mycorrhization parameters change when earthworms are added to the inoculation substrate. Seedlings were analyzed 6 and 12 months after spore inoculation. Mycorrhization with or without earthworms revealed contrasting effects on fine root biomass and morphology of silver fir seedlings. Only a few of the assessed fine root parameters showed statistically significant response, namely higher fine root biomass and fine root tip density in inoculated seedlings without earthworms 6 months after inoculation, lower fine root tip density when earthworms were added, the specific root tip density increased in inoculated seedlings without earthworms 12 months after inoculation, and general negative effect of earthworm on branching density. Silver fir was confirmed as a suitable host partner for commercial mycorrhization with truffles, with 6% and 35% mycorrhization 6 months after inoculation and between 36% and 55% mycorrhization 12 months after inoculation. The effect of earthworms on mycorrhization of silver fir with Tuber aestivum was positive only after 6 months of mycorrhization, while this effect disappeared and turned insignificantly negative after 12 months due to the secondary effect of grazing on ectomycorrhizal root tips.

scholarly journals Molecular Identification of Ectomycorrhizal Mycelium in Soil Horizons

2003 ◽  
Vol 69 (1) ◽  
pp. 327-333 ◽  
Author(s):  
Renske Landeweert ◽  
Paula Leeflang ◽  
Thom W. Kuyper ◽  
Ellis Hoffland ◽  
Anna Rosling ◽  
...  
Keyword(s):  
Molecular Identification ◽  
Sequence Similarity ◽  
Mineral Soil ◽  
Molecular Techniques ◽  
Root Tip ◽  
Root Tips ◽  
Soil Horizons ◽  
Novel Approach ◽  
Total Dna ◽  
Identification Techniques

ABSTRACT Molecular identification techniques based on total DNA extraction provide a unique tool for identification of mycelium in soil. Using molecular identification techniques, the ectomycorrhizal (EM) fungal community under coniferous vegetation was analyzed. Soil samples were taken at different depths from four horizons of a podzol profile. A basidiomycete-specific primer pair (ITS1F-ITS4B) was used to amplify fungal internal transcribed spacer (ITS) sequences from total DNA extracts of the soil horizons. Amplified basidiomycete DNA was cloned and sequenced, and a selection of the obtained clones was analyzed phylogenetically. Based on sequence similarity, the fungal clone sequences were sorted into 25 different fungal groups, or operational taxonomic units (OTUs). Out of 25 basidiomycete OTUs, 7 OTUs showed high nucleotide homology (≥99%) with known EM fungal sequences and 16 were found exclusively in the mineral soil. The taxonomic positions of six OTUs remained unclear. OTU sequences were compared to sequences from morphotyped EM root tips collected from the same sites. Of the 25 OTUs, 10 OTUs had ≥98% sequence similarity with these EM root tip sequences. The present study demonstrates the use of molecular techniques to identify EM hyphae in various soil types. This approach differs from the conventional method of EM root tip identification and provides a novel approach to examine EM fungal communities in soil.

scholarly journals The use of disturbed and undisturbed forest by masked titi monkeys Callicebus personatus melanochir is proportional to food availability

Oryx ◽  
2002 ◽  
Vol 36 (2) ◽  
pp. 133-139 ◽  
Author(s):  
Stefanie Heiduck
Keyword(s):  
Home Range ◽  
Atlantic Rainforest ◽  
Forest Types ◽  
Clear Cut ◽  
Titi Monkey ◽  
Eastern Brazil ◽  
Titi Monkeys ◽  
Undisturbed Forest ◽  
Disturbed Forest ◽  
One Year

The masked titi Callicebus personatus melanochir is a threatened primate, endemic to the Atlantic rainforest of eastern Brazil. The Atlantic rainforest has been reduced to only 5% of its former extent, and only 2% consists of undisturbed forest. The survival of the masked titi monkey is therefore dependent on its ability to utilise disturbed forest habitat. A group of four masked titi monkeys was observed for one year in a plot that contained both disturbed and undisturbed forest. The group used a home range of 22 ha, which comprised 58% undisturbed forest, 31% selectively logged forest and 11% forest that was regrowing after a clear-cut. The titi monkeys did not use the different forest types in proportion to the availability of each within their home range: undisturbed forest was used more than expected from its proportional availability, and disturbed forest was used less than expected. Use of forest types appeared to be determined by the availability of food resources. Undisturbed forest had the most food per unit area and regrowing forest had the least. This study shows that masked titi monkeys may be able to survive in disturbed forest habitats if these areas are of high enough quality to contain sufficient food and other resources.

Partial cut harvesting and ectomycorrhizae: early effects in Douglas-fir-larch forests of western Montana

1980 ◽  
Vol 10 (3) ◽  
pp. 436-440 ◽  
Author(s):  
A. E. Harvey ◽  
M. J. Larsen ◽  
M. F. Jurgensen
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Douglas Fir ◽  
The Other ◽  
Western Montana ◽  
Root Tips ◽  
Residue Removal ◽  
Larch Forests ◽  
Early Effects

Numbers of ectomycorrhizae were assessed 3 years after harvesting approximately 50% of the overstory in two Douglas-fir-larch stands in western Montana, one was subjected to intensive residue removal, the other broadcast burned 1 year after harvest. Numbers of active ectomycorrhizal root tips were significantly reduced in the broadcast burned stand compared to either the intensively utilized stand or to an adjacent, undisturbed stand. This indicates that on difficult-to-regenerate sites, particularly where soil organic matter is low, it may be advantageous to dispose of slash created in partial cuts by means other than burning.

Sign in / Sign up

Export Citation Format

Share Document