scholarly journals Conversion of Pinus nigra Plantations with Natural Regeneration in the Slovenian Karst: The Importance of Intermediate, Gradually Formed Canopy Gaps

Forests ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1136
Author(s):  
Jurij Diaci ◽  
Tomaž Adamič ◽  
Andrej Rozman ◽  
Gal Fidej ◽  
Dušan Roženbergar
Keyword(s):  
Natural Regeneration ◽  
Soil Depth ◽  
Pinus Nigra ◽  
Quercus Petraea ◽  
Summer Drought ◽  
Natural Disturbances ◽  
Site Factors ◽  
Insect Infestations ◽  
One Year ◽  
Ostrya Carpinifolia

Since the mid-19th century, Pinus nigra plantations have played a key role in the restoration of degraded European landscapes. Nowadays, these plantations are aging and prone to natural disturbances, insect infestations, and diseases. For their successful gradual conversion, knowledge of optimal gap spatiotemporal dynamics is crucial. We studied herb and natural regeneration patterns along with site factors on 477 subplots within 44 plots distributed over four stand types: closed stand (14% diffuse light), open stand (21%), gap edge (23%), and gap (57%). Despite the abundant Quercus petraea, Q. cerris, and Q. pubescens mast year, no one-year seedlings were recorded, which is likely due to the summer drought. Short seedlings (h < 20 cm) of Quercus sp., Fraxinus ornus and Ostrya carpinifolia were more successful within closed stands. Short Quercus seedlings were positively associated with soil depth and negatively associated with soil nutrients, distance to seed trees, and Sesleria autumnalis coverage. Taller Quercus seedlings required more light than both of its strongest competitors and were positively related to humid soils and less rocky sites. Ungulate overbrowsing significantly impeded natural regeneration. The results indicate a satisfactory Quercus density for conversion and the importance of advanced regeneration, which should be gradually, but persistently, released by progressively widening gaps.

scholarly journals Evaluation of the influence of dendrometric and ecological factors on the natural regeneration of “Cedrus Atlantica Mannetti” In Ain Antar forest, Algeria

2018 ◽  
Vol 19 (1) ◽  
pp. 85-94
Author(s):  
Mourad Bared ◽  
◽  
Mohamed Berrichi ◽  
Keyword(s):  
Natural Regeneration ◽  
Soil Depth ◽  
Ecological Factors ◽  
Basal Area ◽  
Cedrus Atlantica ◽  
Litter Cover ◽  
Ecological Parameters ◽  
One Year ◽  
Survival Of Seedlings

This study aims to evaluate the effect of dendrometric and ecological factors on the natural regeneration of the Atlas cedar "Cedrus atlantica Mannetti" in AinAntarforest,Algeria. This study wascarried out in 14 circular plots of 500 m2area.In order to quantify the seedlingclasses, six sub-plots of 1 m2were installed in each plot.The results of the dendrometric data showedthe presence of a "Gaussian distribution" with a dominance offruitingdiameters(37.5 and 57.5 cm).The results of ecological parameters revealedthat in high altitudes, above 1300 m, natural regeneration seemedto be relatively difficult (30% compared to low and medium altitudes). On slopes greater than 30%, seedlings of less than one year old were less present (20 % compared to the seven first plots). The role of the vegetation cover (40–0%), the litter cover (30–40%) and of the soil depth (shallow and deep) appearedto favor the survival of seedlings, especiallywhen they werestill young. The correlation analysis indicatedthat the different seedling classes became less numerous when altitude, slope and basal area increased.

scholarly journals Drought and rewetting events enhance nitrate leaching and seepage-mediated translocation of microbes from beech forest soils

2020 ◽  
Author(s):  
Markus Krüger ◽  
Karin Potthast ◽  
Beate Michalzik ◽  
Alexander Tischer ◽  
Kirsten Küsel ◽  
...  
Keyword(s):  
Forest Soils ◽  
Nitrate Leaching ◽  
Soil Depth ◽  
Groundwater Resources ◽  
Beech Forest ◽  
Summer Drought ◽  
Ammonia Oxidizing Bacteria ◽  
Litter Layer ◽  
Drought Period ◽  
Potential Nitrification

AbstractNitrification in forest soils is often associated with increased leaching of nitrate to deeper soil layers with potential impacts on groundwater resources, further enhanced under scenarios of anthropogenic atmospheric nitrogen deposition and predicted weather extremes. We aimed to disentangle the relationships between soil nitrification potential, seepage-mediated nitrate leaching and the vertical translocation of nitrifiers in soils of a temperate mixed beech forest in central Germany before, during and after the severe summer drought 2018. Leaching of nitrate assessed below the litter layer and in 4, 16 and 30 cm soil depth showed high temporal and vertical variation with maxima at 16 and 30 cm during and after the drought period. Maximum of soil potential nitrification activity of 4.4 mg N kg-1 d-1 only partially coincided with maximum nitrate leaching of 10.5 kg N ha-2. Both ammonia oxidizing bacteria (AOB) and ammonia oxidizing archaea (AOA) were subject to translocation by seepage, and AOB decreased at least by half and AOA increased by one to three orders of magnitude in their abundance in seepage with increasing soil depth. On the level of the total bacterial population, an increasing trend with depth was also observed for Cand. Patescibacteria while Bacteroidetes were strongly mobilized from the litter layer but poorly transported further down. Despite stable population densities in soil over time, abundances of AOA, AOB and total bacteria in seepage increased by one order of magnitude after the onset of autumn rewetting. Predicted future higher frequency of drought periods in temperate regions may result in more frequent seepage-mediated seasonal flushes of nitrate and bacteria from forest soils. Moreover, the observed translocation patterns point to taxon-specific differences in the susceptibility to mobilization, suggesting that only selected topsoil derived microbial groups are likely to affect subsoil or groundwater microbial communities and their functional potential.

scholarly journals Four-year-performance of oak and pine seedlings following mechanical site preparation with lightweight excavators

Silva Fennica ◽  
2021 ◽  
Vol 55 (2) ◽  
Author(s):  
Noé Dumas ◽  
Mathieu Dassot ◽  
Jonathan Pitaud ◽  
Jérôme Piat ◽  
Lucie Arnaudet ◽  
...  
Keyword(s):  
Vegetation Cover ◽  
Untreated Control ◽  
Seedling Survival ◽  
Pinus Nigra ◽  
Quercus Petraea ◽  
Site Preparation ◽  
Pteridium Aquilinum ◽  
Preparation Methods ◽  
Basal Diameter ◽  
Mechanical Site Preparation

Mechanical site preparation methods that used tools mounted on lightweight excavators and that provided localised intensive preparation were tested in eight experimental sites across France where the vegetation was dominated either by (L.) Moench or (L.) Kuhn. Two lightweight tools (Deep Scarifier: DS; Deep Scarifier followed by Multifunction Subsoiler: DS+MS) were tested in pine ( L., var. (Loudon) Hyl. or Aiton) and oak ( (Matt.) Liebl. or  L.) plantations. Regional methods commonly used locally (herbicide, disk harrow, mouldboard plow) and experimental methods (repeated herbicide application; untreated control) were used as references in the experiments. Neighbouring vegetation cover, seedling survival, height and basal diameter were assessed over three to five years after plantation. For pines growing in , seedling diameter after four years was 37% and 98% greater in DS and DS+MS, respectively, than in the untreated control. For pines growing in , it was 62% and 107% greater in the same treatments. For oak, diameter was only 4% and 15% greater in , and 13% and 25% greater in , in the same treatments. For pines, the survival rate after four years was 26% and 32% higher in and 64% and 70% higher in , in the same treatments. For oak, it was 3% and 29% higher in and 37% and 31% higher in . Herbicide, when applied for three or four years after planting, provided the best growth performances for pines growing in and and for oaks growing in . For these species and site combinations, DS+MS and DS treatments reduced the neighbouring vegetation cover for one to four years following site preparation.Molinia caeruleaPteridium aquilinumPinus sylvestrisPinus nigracorsicanaPinus pinasterQuercus petraeaQuercus roburM. caeruleaP. aquilinumM. caeruleaP. aquilinumM. caeruleaP. aquilinumM. caeruleaP. aquilinumM. caerulea P. aquilinumP. aquilinum

scholarly journals Vegetation responses to season of fire in an aseasonal, fire-prone fynbos shrubland

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3591 ◽  
Author(s):  
Tineke Kraaij ◽  
Richard M. Cowling ◽  
Brian W. van Wilgen ◽  
Diba R. Rikhotso ◽  
Mark Difford
Keyword(s):  
Floristic Composition ◽  
Fire Season ◽  
Summer Drought ◽  
Winter Rainfall ◽  
Recruitment Success ◽  
Floral Diversity ◽  
Four Seasons ◽  
Different Seasons ◽  
Varied Response ◽  
One Year

Season of fire has marked effects on floristic composition in fire-prone Mediterranean-climate shrublands. In these winter-rainfall systems, summer-autumn fires lead to optimal recruitment of overstorey proteoid shrubs (non-sprouting, slow-maturing, serotinous Proteaceae) which are important to the conservation of floral diversity. We explored whether fire season has similar effects on early establishment of five proteoid species in the eastern coastal part of the Cape Floral Kingdom (South Africa) where rainfall occurs year-round and where weather conducive to fire and the actual incidence of fire are largely aseasonal. We surveyed recruitment success (ratio of post-fire recruits to pre-fire parents) of proteoids after fires in different seasons. We also planted proteoid seeds into exclosures, designed to prevent predation by small mammals and birds, in cleared (intended to simulate fire) fynbos shrublands at different sites in each of four seasons and monitored their germination and survival to one year post-planting (hereafter termed ‘recruitment’). Factors (in decreasing order of importance) affecting recruitment success in the post-fire surveys were species, pre-fire parent density, post-fire age of the vegetation at the time of assessment, and fire season, whereas rainfall (for six months post-fire) and fire return interval (>7 years) had little effect. In the seed-planting experiment, germination occurred during the cooler months and mostly within two months of planting, except for summer-plantings, which took 2–3 months longer to germinate. Although recruitment success differed significantly among planting seasons, sites and species, significant interactions occurred among the experimental factors. In both the post-fire surveys and seed planting experiment, recruitment success in relation to fire- or planting season varied greatly within and among species and sites. Results of these two datasets were furthermore inconsistent, suggesting that proteoid recruitment responses are not related to the season of fire. Germination appeared less rainfall-dependent than in winter-rainfall shrublands, suggesting that summer drought-avoiding dormancy is limited and has less influence on variation in recruitment success among fire seasons. The varied response of proteoid recruitment to fire season (or its simulation) implies that burning does not have to be restricted to particular seasons in eastern coastal fynbos, affording more flexibility for fire management than in shrublands associated with winter rainfall.

scholarly journals Föhrenverjüngung: Plastizität und Akklimatisation in einem trockeneren Klima

2018 ◽  
Vol 169 (5) ◽  
pp. 269-278
Author(s):  
Barbara Moser ◽  
Christoph Bachofen ◽  
Thomas Wohlgemuth
Keyword(s):  
Scots Pine ◽  
Natural Regeneration ◽  
Common Garden ◽  
Forest Steppe ◽  
Short Time Scale ◽  
Summer Drought ◽  
Spring Precipitation ◽  
Pine Regeneration ◽  
A Minor ◽  
Rhone Valley

Pine regeneration: plasticity and acclimation in a dryer climate Increasing summer drought might limit the natural regeneration of Scots pine stands at low elevations of the Rhone valley. Common garden experiments at the forest-steppe ecotone have shown that emergence and establishment of Scots pine primarily depend on spring precipitation and, to a minor degree, on summer drought and rising temperatures. Scots pine seedlings acclimated rapidly to drought periods by favouring root to shoot growth. In the second year, the saplings were already adapted to drought so that most of them survived an extended spring and summer drought, as recorded at Sion twelve times during the last 154 years. Only an extreme summer drought – no water from June to September – killed 14.7% of the Scots pine saplings. Surprisingly, they were even able to acclimate to such extreme drought events: after the same extreme summer drought in the third year, mortality dropped below 5%. In general, the Scots pine was very plastic, i.e. seedlings and saplings changed their phenotype depending on environmental conditions. But we also found genetic adaptation: Scots pine originating from regions with pronounced summer drought, including populations from lower elevations in the Rhone valley, produced more biomass than those from moister regions in all treatment combinations. Black pine reacted similarly to the treatments like Scots pine, but it grew faster and more saplings survived the first extreme summer drought. These results show that Scots pine from low elevations of the Rhone valley is one of the most drought-tolerant provenances in Europe. Thanks to its high phenotypic plasticity and the ability of seedlings and saplings to acclimate to drought on a short time scale, natural regeneration of Scot pine at low elevations of the Rhone valley is likely to occur also under future conditions, but maybe less frequent than today.

scholarly journals Factors Influencing the Natural Forest Regeneration at Khadimnagar National Park, Bangladesh

2021 ◽  
Vol 11 (1) ◽  
pp. 73-83
Author(s):  
MAHEDI HASAN LIMON ◽  
SAIDA HOSSAIN ARA ◽  
MOHAMMAD GOLAM KIBRIA
Keyword(s):  
Species Richness ◽  
Bulk Density ◽  
Total Variation ◽  
Soil Ph ◽  
Tree Species ◽  
Natural Regeneration ◽  
National Park ◽  
Canopy Openness ◽  
Site Factors ◽  
Tree Species Richness

Natural regeneration is an indicator of a healthy forest, hence, understanding the influence of site factors on natural regeneration is a significant concern for ecologists. This work aimed to assess the impact of site factors on natural tree regeneration at Khadimnagar National Park (KNP). Biotic factors (tree density, tree species richness, and basal area), physical factors (elevation, canopy openness), and soil properties (bulk density, moisture content, soil pH, organic matter, sand, silt, and clay) data were investigated from 71 sample plots to examine their effects on natural regeneration density and richness in KNP. Stepwise multiple linear regression analysis was done to predict both regeneration density and regeneration richness. The results showed that soil pH (p<0.001), canopy openness (p<0.001), tree species richness (p<0.01), and bulk density (p<0.01) had a significant effect on regeneration density, explaining 42% of the total variation. Regeneration richness was driven by four factors: tree species richness (p<0.01), soil pH (p<0.001), elevation (p<0.01), and canopy openness (p<0.01) with a model that explained 60% of the total variation. This study observed that soil pH, tree species richness, and canopy openness are the main controlling factors that influenced both the density and richness of regenerating species in KNP. Therefore, these findings have implications for natural resource management, especially in selecting suitable silvicultural systems in a tropical forest under protected area management where enhanced tree cover and conservation of biodiversity are needed.

scholarly journals Soil Microbial Biomass and Community Composition Relates to Poplar Genotypes and Environmental Conditions

Forests ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 262 ◽  
Author(s):  
Leszek Karliński ◽  
Sabine Ravnskov ◽  
Maria Rudawska
Keyword(s):  
Microbial Biomass ◽  
Microbial Communities ◽  
Community Composition ◽  
Soil Depth ◽  
Abiotic Factors ◽  
Soil Conditions ◽  
Main Role ◽  
Site Factors ◽  
Host Genotype ◽  
The Impact

Poplars, known for their diversity, are trees that can develop symbiotic relationships with several groups of microorganisms. The genetic diversity of poplars and different abiotic factors influence the properties of the soil and may shape microbial communities. Our study aimed to analyse the impact of poplar genotype on the biomass and community composition of the microbiome of four poplar genotypes grown under different soil conditions and soil depths. Of the three study sites, established in the mid-1990s, one was near a copper smelter, whereas the two others were situated in unpolluted regions, but were differentiated according to the physicochemical traits of the soil. The whole-cell fatty acid analysis was used to determine the biomass and proportions of gram-positive, gram-negative and actinobacteria, arbuscular fungi (AMF), other soil fungi, and protozoa in the whole microbial community in the soil. The results showed that the biomass of microorganisms and their contributions to the community of organisms in the soil close to poplar roots were determined by both factors: the tree-host genotype and the soil environment. However, each group of microorganisms was influenced by these factors to a different degree. In general, the site effect played the main role in shaping the microbial biomass (excluding actinobacteria), whereas tree genotype determined the proportions of the fungal and bacterial groups in the microbial communities and the proportion of AMF in the fungal community. Bacterial biomass was influenced more by site factors, whereas fungal biomass more by tree genotype. With increasing soil depth, a decrease in the biomass of all microorganisms was observed; however, the proportions of the different microorganisms within the soil profile were the result of interactions between the host genotype and soil conditions. Despite the predominant impact of soil conditions, our results showed the important role of poplar genotype in shaping microorganism communities in the soil.

scholarly journals The effects of cutting regimes on natural regeneration in submountain beech forests: species diversity and abundance

2008 ◽  
Vol 54 (No. 12) ◽  
pp. 533-544 ◽  
Author(s):  
M. Barna
Keyword(s):  
Natural Regeneration ◽  
Growth Conditions ◽  
The Other ◽  
Limiting Factor ◽  
Beech Forests ◽  
Clear Cut ◽  
One Year ◽  
Cutting Regimes ◽  
Cutting Intensity ◽  
The Given

The paper summarizes the results of 15-year natural regeneration for beech of five plots with different densities situated in the Western Carpathians Mts. Three of the plots were subjected to differently intensive shelterwood cuttings (plots L, M, H), one plot was clear-cut (CC), and one was left without intervention – as a control (C). The number of one-year-old seedlings decreased proportionally with increasing cutting intensity. The ANOVA results document a significant influence of cutting intensity on the abundance of both one-year-old and older seedlings. The abundance of beech seedlings was initially increasing with increasing cutting intensity, and, having reached the peak on plot M (medium intensity), there followed a decrease in the seedling abundance. Lower numbers of beech seedlings on plots subjected to less intensive cutting (C, L) result from less favourable growth conditions in comparison with plot M. On the other hand, cutting of higher intensity (H, CC) resulted in lower numbers of fructifying parent trees. The medium cut intervention having provided the plot M with stocking of 0.5 (50% of the stand) resulted in a lower number of seed resources (limiting factor for natural regeneration). However, for the other factor – seedling establishment (survival and recruitment) this plot (M) represents an ecological optimum in beech regeneration in the given conditions.

scholarly journals Growth of Austrian pine (Pinus nigra Arnold) treated with soil conditioners on Loket spoil bank

2012 ◽  
Vol 52 (No. 12) ◽  
pp. 556-564 ◽  
Author(s):  
P. Bulíř
Keyword(s):  
Substrate Surface ◽  
Pinus Nigra ◽  
Height Growth ◽  
Elongation Growth ◽  
Seedling Mortality ◽  
Spoil Bank ◽  
Soil Conditioners ◽  
Second Year ◽  
One Year ◽  
The Given

The effects of soil conditioners Frisol, TerraCottem, Bi-algeen, and fertilisers Silvamix Forte and Cererit on the welfare of Austrian pine were observed in a seven-year experiment on Loket spoil bank. Simultaneously the economic aspects of growing the Austrian pine until the stage of established plantation were examined. The application of products one year and a half after planting did not cause seedling mortality. The elongation growth of young plants conditioned by the application of Silvamix Forte and Frisol was statistically significant whereas these effects manifested themselves in the second year: they persisted till the end of the experiment for Silvamix Forte, and for three years in total for Frisol. The other products &ndash; TerraCottem, Bi-algeen and Cererit &ndash; also showed generally better, though statistically insignificant results as compared to those of the control plants. The elongation growth for all products culminated in the fifth year and then declined. The stem diameter growth for the best products reached its maximum in the second year. Regarding the overall height growth after seven years, the average number of the highest plants on the experiment location was on plots treated with Silvamix Forte; these plants exceeded the control plants by 46.2 cm. Pines treated with Frisol were higher by 23.4&nbsp;cm. However, the application of soil conditioners and fertilisers to the given location proved economically ineffective because there was no need to improve the soil at the location, the same applies to mowing and hoeing since almost no forest weed grew there and the substrate surface remained well-aerated and porous.

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