scholarly journals Uneven-aged silviculture of Scots pine in Bohemia and Central Spain: comparison study of stand reaction to transition and long-term selection management

2020 ◽  
Vol 66 (No. 1) ◽  
pp. 22-35 ◽  
Author(s):  
Josef Gallo ◽  
Lukáš Bílek ◽  
Václav Šimůnek ◽  
Sonia Roig ◽  
José Alfredo Bravo Fernández
Keyword(s):  
Scots Pine ◽  
Sustainable Forest Management ◽  
Environmental Changes ◽  
Basal Area ◽  
Diversity Indices ◽  
Mountain Range ◽  
Central Spain ◽  
Ecological Requirements ◽  
Intensively Managed

The achievement of sustainable forest management requires the incorporation of ongoing environmental changes into long-term planning. Moreover, in time of climatic change and changing company demands, importance of Scots pine (Pinus sylvestris L.) is still increasing at the expense of other tree species due to its low ecological requirements. The aim of the study was to compare the structure and production of Scots pine stands managed under different silvicultural systems on four research plots, assess the structural and diversity indices, and analyse the increment structure using tree-ring dating in the Czech Republic and Spain. Area of study was Western Bohemian and Guadarrama Mountain range in Central Spain. The results indicate that stand volume on the investigated plots ranged from 231 to 441 m<sup>3</sup>∙ha<sup>–1</sup> with tree density 276–996 trees∙ha<sup>–1</sup>. Intensively managed (uneven-aged) permanent research plots showed increased growth on basal area. The difference was evident also for older trees. The transition to uneven-aged forest does not negatively influence stocking and wood production and provide higher benefits for diversity and structural complexity in comparison to regular stands.

Experimental manipulation of habitat structures in intensively managed spruce plantations to increase their value for biodiversity conservation

2015 ◽  
Vol 91 (02) ◽  
pp. 161-175 ◽  
Author(s):  
David A. MacLean ◽  
Evan Dracup ◽  
Franck Gandiaga ◽  
Sean R. Haughian ◽  
Allison MacKay ◽  
...  
Keyword(s):  
Biodiversity Conservation ◽  
Bird Species ◽  
Basal Area ◽  
Experimental Manipulation ◽  
Ground Vegetation ◽  
Mammal Species ◽  
Commercial Thinning ◽  
Biomass Removal ◽  
Intensively Managed

Six intensively managed white spruce (Picea glauca (Moench) Voss) plantations located in three general landscape contexts (plantation dominated, hardwood dominated, and mixed hardwood and plantation) in northern New Brunswick underwent alternative commercial thinning (CT) treatments: 1) an unthinned control; and three 40% basal area CT removals, with 2) slash and tops remaining on site (status quo CT), 3) branches and tops extracted from the site (biomass removal CT), and 4) clumps of unthinned trees left, and one-half girdled to create snags (enhanced structure CT). We examined responses of taxa that have a clear connection to deadwood and thinning response: beetles and bird species that are directly dependent upon deadwood, ground vegetation species sensitive to disturbance, and small mammals that have been observed to have low density in planted stands. Results three years post-thinning showed that crown width and tree growth responded positively to CT, and herbaceous vegetation diverged from reference stands and unthinned treatments with CT, but greatest compositional change was associated with biomass removal CT. Beetles responded positively to CT, small mammal species responded both positively (red-backed voles) and negatively (woodland jumping mice) to CT, but areas dominated by plantations had negative effects on voles. Effects of CT on songbirds were unclear and their quantification would require larger treated blocks, but maintenance of habitat at the landscape level is essential for the conservation of bird species that require deadwood. The experimental biomass removal CT was least similar to both unthinned and older unmanaged stands, and may therefore be detrimental to biodiversity conservation efforts. These results are only the initial three years after treatment but set the study up to permit a long-term legacy of determining long-term responses of taxa over stand development.

scholarly journals Paleontological methods in environmental science

1992 ◽  
Vol 6 ◽  
pp. 40-40
Author(s):  
Grace S. Brush ◽  
Humaira Khan
Keyword(s):  
Water Quality ◽  
Environmental Conditions ◽  
Human Disturbance ◽  
Large Scale ◽  
Environmental Changes ◽  
Nitrogen And Phosphorus ◽  
Ecological Requirements ◽  
Inorganic Substances ◽  
Stratigraphic Record

Long term environmental changes, induced both by natural and anthropogenic causes, cannot be assessed by looking solely at historical records of temperature, rainfall, water quality, etc. Frequently, such records are nonexistent. Where they do exist, they are often too short to be of much use. However, sediments contain a stratigraphic record of environmental change that allows comparison of the historic period influenced largely by humans, with prehistoric time when climate was the major determinant of environmental conditions.The stratigraphic record contains various fossilized organic materials which reflect environmental conditions at the time of the their deposition. Most abundant are pollen and spores of aquatic and terrestrial plants. Correspondence between pollen assemblages and vegetation has been found in all parts of the world. Therefore stratigraphic changes in pollen taxa reveal much information regarding the vegetational history of a region. Knowledge of the ecological requirements of various taxa can then be used to infer past climatic conditions. For example, dominance of Juglans (walnut) pollen indicates wet conditions while abundance of Pteridium (bracken fern) spores is an indicator of fire, suggesting drier conditions. Pollen can also be used to trace human disturbance to the environment. Sharp increases in the pollen of Ambrosia (ragweed) in sediment cores indicate large scale land clearance by man.Seeds preserved in sediments provide another measure of temporal vegetational change. Generally, seeds are not dispersed far from the parent plant; hence they provide a more local record of vegetation than pollen. A decrease in seeds of aquatic plants and increase in seeds of higher ground taxa when accompanied by increased sedimentation rates is an indicator of infilling of an aquatic environment. If unaccompanied by increased sedimentation, the change more likely represents lowering of sea level. Disappearance of seeds of taxa sensitive to turbidity and eutrophication provide another long term record of human disturbance.Distributions of diatoms are affected by temperature, salinity, oxygen, light availability and nutrient levels in the water. Therefore changes in diatom species preserved in the sediments can be used as indicators of climate, turbidity, anoxia and eutrophication in aquatic ecosystems.Many inorganic substances preserved in sediments also provide a long term record of changes in the environment. Nitrogen and phosphorus can be measured in cores and used as a surrogate record of water quality in lakes and estuaries. Sharp increases in sedimentary accumulation of metals record wastewater discharge and fuel emissions, related to human activity.

Yield Comparisons from Even-Aged and Uneven-Aged Loblolly-Shortleaf Pine Stands

1988 ◽  
Vol 12 (2) ◽  
pp. 107-114 ◽  
Author(s):  
James M. Guldin ◽  
James B. Baker
Keyword(s):  
Pinus Taeda ◽  
Coastal Plain ◽  
Basal Area ◽  
Selection Method ◽  
Shortleaf Pine ◽  
Large Size ◽  
Intensively Managed ◽  
Pinus Taeda L ◽  
Long Term Studies

Abstract Empirical yields for a 36-year management period are presented for seven long-term studies on similar sites in loblolly-shortleaf pine (Pinus taeda L.-P. echinata Mill.) stands on the upper southern coastal plain of southern Arkansas and northern Louisiana. Total merchantable cubic-foot yields are highest for conventionally managed even-aged plantations; sawtimber cubic-foot yields are highest for intensively managed even-aged plantations and intensively managed uneven-aged stands. However, uneven-aged stands have higher board-foot sawtimber yields than the most productive even-aged stands, particularly in comparisons using the Doyle log rule. It is hypothesized that the even-aged plantations have higher cubic-foot yields because they are more fully stocked with trees of merchantable size. Conversely, the uneven-aged stands have higher board-foot yields because of the greater proportion and continuous supply of sawtimber basal area, especially in stems of large size, which can be developed using the uneven-aged selection method. South J. Appl. For. 12(5):107-114

Richesse Floristique Et Stockage De Carbone De La Zone Agricole De La Forêt De Kissila Dans Le Mayombe Congolais

2021 ◽  
Vol 17 (40) ◽  
pp. 1
Author(s):  
Luc Kimpolo ◽  
Saint Fédriche Ndzai, ◽  
Félix Koubouana
Keyword(s):  
Local Community ◽  
Sustainable Forest Management ◽  
Secondary Forest ◽  
Structural Parameters ◽  
Basal Area ◽  
Forest Degradation ◽  
Diversity Indices ◽  
Allometric Equation ◽  
Above Ground Biomass ◽  
Ground Biomass

Sustainable forest management remains a major challenge for the international and local community in addressing deforestation and forest degradation. These forests are now experiencing a very marked degradation, mainly caused by agricultural practices. This study assessed the floristic richness and the stock of aerial carbon in order to contribute to a better knowledge of the natural resources of this forest. Five plots of 50m each have been installed with a total area of 12,500m² or 1,25ha. All trees of Diameter to Chest Height (DHP) ≥ 10cm were surveyed at 1.30m from the soil in each plot. Species richness, ecological spectrum, floristic diversity indices, and structural parameters were studied. Above-ground biomass was calculated using Djomo's allometric equation and carbon estimation by above-ground biomass x 0.47. The floristic inventory helped to identify 309 trees that were inventoried, comprising 79 species, 63 genera, and 32 families. The family of Annonaceae (11.39 %) is the most qualitatively represented while that of Olacaceae (11.65%) is the most quantitatively represented. Diversity indices tend to be 5, while density per hectare and average basal area are 247 trees and 10.71 m²/ha. The average calculated aboveground biomass is 311.76tC/ha and the average carbon stock is 89.5tC/ha. This study shows that the forest in this area can be classified as a highly disturbed secondary forest. La gestion durable des forêts reste un problème majeur que doit faire face la communauté internationale et locale dans la lutte contre la déforestation et la dégradation des forêts. Ces forêts connaissent de nos jours une dégradation très accentuée principalement causée par les pratiques agricoles. Cette étude a pour objectif d’évaluer la richesse floristique et d’estimer le stock de carbone aérien afin de contribuer à une meilleure connaissance des ressources naturelles de cette forêt du Mayombe en général et celle du village Kissila en particulier. Cinq parcelles de 50 m de côté chacune ont été installées avec une superficie totale de 12.500 m² soit 1,25 ha. Tous les arbres de Diamètre à Hauteur de la Poitrine (DHP) ≥10 cm ont été inventoriés à 1,30 m du sol dans chaque parcelle. La richesse spécifique, le spectre écologique, les indices de diversité floristique, ainsi que les paramètres structuraux ont été étudiés. La biomasse aérienne a été calculée à partir de l’équation allométrique de Djomo et l’estimation du carbone par la biomasse aérienne x 0,47. L’inventaire floristique a permis d’identifier 309 arbres répartis en 79 espèces, 63 genres et 32 familles. La famille des Annonaceae (11,39 %°) est la plus représentée qualitativement et celle des Olacaceae quantitativement (11,65%). Les indices de diversité de Shannon tendent vers 5, la densité à l’hectare et la surface terrière moyenne sont de 247 arbres et 10,71 m²/ha. La biomasse aérienne moyenne calculée est de 311,76tC/ha et le stock de carbone aérien moyen est de 89,5 tC/ha. Cette étude montre que la forêt de cette zone peut être classée comme une forêt secondaire fortement perturbée.

Long-term black spruce plantation growth and structure after release and juvenile cleaning: A 24-year study

2009 ◽  
Vol 85 (3) ◽  
pp. 417-426 ◽  
Author(s):  
Guillaume Cyr ◽  
Nelson Thiffaul
Keyword(s):  
Sustainable Forest Management ◽  
Stand Structure ◽  
Black Spruce ◽  
Basal Area ◽  
Vegetation Management ◽  
Growth And Yield ◽  
Long Term Study ◽  
Conifer Plantations ◽  
Mechanical Release

Vegetation management is crucial to meet growth and yield objectives in conifer plantations. But, the combined and longterm effects of mechanical release and juvenile cleaning on growth and stand structure have yet to be documented in black spruce plantations. A long-term study was carried out in Quebec (Canada) to evaluate the interactions between initial mechanical release at age 2 years and juvenile cleaning at age 14 years (i.e., a second release treatment) on planted black spruce survival and dimensions at age 24 years. Population structure and stand species composition were also assessed. Results showed that release and juvenile cleaning had an additive, positive effect on survival, diameter at breast height (DBH), height, crown width, crown length, and the last 5-year DBH and height increments. Juvenile cleaning effects were of higher magnitude than release effects, especially on 5-year DBH increment. Combination of both treatments reduced DBH and height variability of saplings, whereas juvenile cleaning alone resulted in a higher proportion of saplings occupying higher height classes. Total merchantable basal area was constant among treatments. But, without juvenile cleaning, hardwoods occupied a higher proportion of the basal area and were taller than spruces. In a context of sustainable forest management, in which conifer plantations are expected to offer high wood yield, our results demonstrate the importance of juvenile cleaning following initial mechanical release to promote crop tree growth and yield. Key words: plantation, vegetation management, black spruce, growth, stand development

scholarly journals Intra- and Inter-Annual Growth Patterns of a Mixed Pine-Oak Forest under Mediterranean Climate

Forests ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1746
Author(s):  
Elisabet Martínez-Sancho ◽  
Emilia Gutiérrez ◽  
Cristina Valeriano ◽  
Montse Ribas ◽  
Margarita I. Popkova ◽  
...  
Keyword(s):  
Scots Pine ◽  
Growth Pattern ◽  
Species Coexistence ◽  
Basal Area ◽  
Climatic Conditions ◽  
Growth Patterns ◽  
Physiological Adaptation ◽  
Growth Trend ◽  
Temperature And Precipitation

Temperature and precipitation variability throughout the year control the intra-annual dynamics of tree-ring formation. Physiological adaptation of trees to climate change is among the key issues to better understand and predict future forest performance and composition. In this study, we investigated the species’ coexistence and performance of Scots pine and pubescent oak growing in a mixed sub-Mediterranean forest in the northeast of the Iberian Peninsula. We assessed intra-annual cumulative growth patterns derived from band dendrometers during four consecutive growing seasons and long-term changes in basal area increment for the period 1950–2014. Our results revealed that Scots pine followed an intra-annual bimodal growth pattern. Scots pine growth was mainly limited by water availability at intra-annual, interannual and decadal time scales, which resulted in a negative long-term growth trend. Conversely, oak displayed a unimodal growth pattern, which was less climatically constrained. A significant increase in basal area of oak denotes an overall better potential acclimation to prevailing climatic conditions at the expenses of a higher risk of physiological failure during extreme climate events.

Designing a CRM Framework for online & offline sports footwear retailers

2015 ◽  
Vol 3 (1) ◽  
Author(s):  
Rodrigo Cueva ◽  
Guillem Rufian ◽  
Maria Gabriela Valdes
Keyword(s):  
Environmental Changes ◽  
Customer Relationship ◽  
Business Strategies ◽  
Economic Sectors ◽  
Running Shoes ◽  
Brick And Mortar ◽  
Key Factor ◽  
On Line ◽  
The Impact

The use of Customer Relationship Managers to foster customers loyalty has become one of the most common business strategies in the past years.  However, CRM solutions do not fill the abundance of happily ever-after relationships that business needs, and each client’s perception is different in the buying process.  Therefore, the experience must be precise, in order to extend the loyalty period of a customer as much as possible. One of the economic sectors in which CRM’s have improved this experience is retailing, where the personalized attention to the customer is a key factor.  However, brick and mortar experiences are not enough to be aware in how environmental changes could affect the industry trends in the long term.  A base unified theoretical framework must be taken into consideration, in order to develop an adaptable model for constructing or implementing CRMs into companies. Thanks to this approximation, the information is complemented, and the outcome will increment the quality in any Marketing/Sales initiative. The goal of this article is to explore the different factors grouped by three main domains within the impact of service quality, from a consumer’s perspective, in both on-line and off-line retailing sector.  Secondly, we plan to go a step further and extract base guidelines about previous analysis for designing CRM’s solutions focused on the loyalty of the customers for a specific retailing sector and its product: Sports Running Shoes.

Past testate amoeba communities in landslide mountain fens (Polish Carpathians): The relationship between shell types and sediment

The Holocene ◽  
2021 ◽  
pp. 095968362199464
Author(s):  
Katarzyna Marcisz ◽  
Krzysztof Buczek ◽  
Mariusz Gałka ◽  
Włodzimierz Margielewski ◽  
Matthieu Mulot ◽  
...  
Keyword(s):  
Environmental Changes ◽  
Testate Amoebae ◽  
Mineral Matter ◽  
Testate Amoeba ◽  
Run Off ◽  
Number Of Factors ◽  
Depth To Water Table ◽  
Polish Carpathians ◽  
The Relationship

Landslide mountain fens formed in landslide depressions are dynamic environments as their development is disturbed by a number of factors, for example, landslides, slopewash, and surface run-off. These processes lead to the accumulation of mineral material and wood in peat. Disturbed peatlands are interesting archives of past environmental changes, but they may be challenging for providing biotic proxy-based quantitative reconstructions. Here we investigate long-term changes in testate amoeba communities from two landslide mountain fens – so far an overlooked habitat for testate amoeba investigations. Our results show that abundances of testate amoebae are extremely low in this type of peatlands, therefore not suitable for providing quantitative depth-to-water table reconstructions. However, frequent shifts of dominant testate amoeba species reflect dynamic lithological situation of the studied fens. We observed that high and stable mineral matter input into the peatlands was associated with high abundances of species producing agglutinated (xenosomic) as well as idiosomic shells which prevailed in the testate amoeba communities in both analyzed profiles. This is the first study that explores testate amoebae of landslide mountain fens in such detail, providing novel information about microbial communities of these ecosystems.

scholarly journals Distribution and altitudinal patterns of carbon and nitrogen storage in various forest ecosystems in the central Yunnan Plateau, China

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jianqiang Li ◽  
Qibo Chen ◽  
Zhuang Li ◽  
Bangxiao Peng ◽  
Jianlong Zhang ◽  
...  
Keyword(s):  
Forest Ecosystems ◽  
Sustainable Forest Management ◽  
Carbon And Nitrogen ◽  
Pinus Yunnanensis ◽  
Yunnan Plateau ◽  
Baseline Information ◽  
C And N ◽  
Quercus Semecarpifolia ◽  
Management Policies

AbstractThe carbon (C) pool in forest ecosystems plays a long-term and sustained role in mitigating the impacts of global warming, and the sequestration of C is closely linked to the nitrogen (N) cycle. Accurate estimates C and N storage (SC, SN) of forest can improve our understanding of C and N cycles and help develop sustainable forest management policies in the content of climate change. In this study, the SC and SN of various forest ecosystems dominated respectively by Castanopsis carlesii and Lithocarpus mairei (EB), Pinus yunnanensis (PY), Pinus armandii (PA), Keteleeria evelyniana (KE), and Quercus semecarpifolia (QS) in the central Yunnan Plateau of China, were estimated on the basis of a field inventory to determine the distribution and altitudinal patterns of SC and SN among various forest ecosystems. The results showed that (1) the forest SC ranged from 179.58 ± 20.57 t hm−1 in QS to 365.89 ± 35.03 t hm−1 in EB. Soil, living biomass and litter contributed an average of 64.73%, 31.72% and 2.86% to forest SC, respectively; (2) the forest SN ranged from 4.47 ± 0.94 t ha−1 in PY to 8.91 ± 1.83 t ha−1 in PA. Soil, plants and litter contributed an average of 86.88%, 10.27% and 2.85% to forest SN, respectively; (3) the forest SC and SN decreased apparently with increasing altitude. The result demonstrates that changes in forest types can strongly affect the forest SC and SN. This study provides baseline information for forestland managers regarding forest resource utilization and C management.

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