Developing a stand density module in LANDIS to improve simulation realism of stand dynamics

2009 ◽  
Author(s):  
Hojung Kim
Keyword(s):  
Stand Density ◽  
Stand Dynamics

scholarly journals Spatiotemporal Structure Features of a Pine Stand on the South Slope of the Eastern Sayan Mountain

2021 ◽  
pp. 34-47
Author(s):  
Natalya F. Ovchinnikova ◽  
Keyword(s):  
Density Ratio ◽  
Stand Density ◽  
Stand Dynamics ◽  
The South ◽  
Horizontal Structure ◽  
Spatiotemporal Structure ◽  
Trunk Diameter ◽  
Sample Area ◽  
South Slope ◽  
Eastern Sayan

Due to relatively long development and long life of forest-forming species most of the conclusions on stand dynamics are based on the data collected by indirect methods of comparative research and analysis of cenosis forming theoretically temporal and spatial succession sequences and need to be verified and clarified. The most reliable results on the stand dynamics can be received on stationary objects such as permanent sample areas. The article presents the analysis results of long-term monitoring (1968–2012) of a pine (Pinus sylvestris L.) stand in low-mountain Eastern Sayan on the south slope with a steepness of 7–8º. The intermittent test of morphometric indicators of trees mapped on the permanent sample area was used. It is shown that the sum of tree trunk cross-section areas at breast height (1.3 m) varied by no more than 10 % with timber reserves on the lower, central and upper equal sites of the sample area during the entire observation period. At the same time heterogeneity of ecological conditions, taking place even on a small section of a smooth slope, influences the plantation self-thinning intensity. In the 42-year-old stand density ratio at lower, central and upper sites was 1:1.5:2.1. Stand density difference along the slope had been decreasing gradually over time, although it remained around 30 % at the time of the last observation. Over the years of observation, 53, 47, and 32 % of pines on the lower, central, and upper sites, respectively, have survived. The calculated average age of the died trees showed that in all groups of natural diameter classes, there was an earlier die-off of pines at the bottom of the slope with an increase in dying age up to the slope. Trees with larger trunk diameter (first telling) died later. All this led to a rearrangement of the horizontal structure of the plantation, a decrease in the average diameter and average volume of trees up to the slope. Typical for mountain forests clinal tree distribution, which affects their morphological indicators, is important to consider when studying and modeling forest ecosystems, as well as when implementing forest management measures. For citation: Ovchinnikova N.F. Spatiotemporal Structure Features of a Pine Stand on the South Slope of the Eastern Sayan Mountains. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 5, pp. 34–47. DOI: 10.37482/0536-1036-2021-5-34-47

Growth table for Corsican pine in Flanders (Belgium)

1991 ◽  
Vol 56 ◽  
Author(s):  
B. Meuleman
Keyword(s):  
Insect Pests ◽  
Sandy Loam ◽  
Stand Density ◽  
Forest Tree ◽  
Permanent Plots ◽  
New Findings ◽  
Volume Increment ◽  
The Mean ◽  
Annual Volume ◽  
Very High

After  its introduction at the start of this century, the Corsican pine has become  an important forest tree in Flanders (Belgium). The total area covered by  Corsican pine is about 11.000 ha. Due to climatological factors it is  virtually absent from the Walloon part of Belgium. Despite the crisis in 1984  - 1986, practical experiences with its vitality and disease resistance are  generally positive. Compared to Scots pine which is native to Belgium, its  productivity and insensitivity for insect pests is large.     To quantify the productivity of Corsican pine, a growth table was  constructed using a method developed by PALM and DAGNELIE. It was based on  data from 321 temporarily and 80 permanent plots distributed over Flanders.  Five yield classes were distinguished according to dominant height at 50  years. For each yield class, a series of tables as a function of treatment  was constructed. Treatments were characterized by the mean annual  circumference increment.     These tables allow to predict the growth of Corsican pines. Such  predictions for the whole range of species are necessary for the development  of a good forestry policy and for timber industries. The tables also provide  information for any given Corsican pine stand that is helpful in practice:  expected productivity, stand density, determination of the felling quantum.      The data show that the productivity of Corsican pine is very high. The very  early culmination of the current annual volume increment and the rather  constant level of the mean annual volume increment after culmination are  interesting new findings. It is also shown that it is possible to work with  long rotation periods. This offers good opportunities for the production of  high quality wood and is also important for the social and ecological role of  the forest.     Productivity is lowest on very dry and sandy soils. A high productivity on  moderately dry sand and loamy sand soils and loamy soils make the Corsican  pine one of the most valuable tree species for the Kempen in Flanders.  Although productivity is very high on well drained sandy loam and loam soils,  plantation of Corsican pine on these locations is not advised.

scholarly journals QuickBird image-based estimation of tree stand density using local maxima filtering method: A case study in a Beijing forest

PLoS ONE ◽  
2018 ◽  
Vol 13 (12) ◽  
pp. e0208256
Author(s):  
Shuhan Wang ◽  
Xiaoli Zhang ◽  
Mohammed Abdelmanan Hassan ◽  
Qi Chen ◽  
Chaokui Li ◽  
...  
Keyword(s):  
Stand Density ◽  
Tree Stand ◽  
Local Maxima ◽  
Filtering Method

Effects of Weed Control in Established Alfalfa (Medicago sativa) on Forage Yield and Quality

Weed Science ◽  
1987 ◽  
Vol 35 (4) ◽  
pp. 564-567 ◽  
Author(s):  
Dennis R. Cosgrove ◽  
Michael Barrett
Keyword(s):  
Medicago Sativa ◽  
Weed Control ◽  
Stand Density ◽  
Forage Yield ◽  
Control Measures ◽  
Acid Detergent Fiber ◽  
Yield And Quality ◽  
Herbicide Treatments ◽  
Forage Yields

The effects of weed control measures in established alfalfa (Medicago sativaL.) on forage yield and quality were investigated at three sites with varying alfalfa densities and weed populations. Herbicide treatments were 0.56 and 1.12 kg/ha metribuzin [4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)-one] applied in fall or spring, respectively, 1.68 kg/ha pronamide [3,5-dichloro (N-1,1-dimethyl-2-propynyl)benzamide] applied in fall, and combinations of these treatments. First-harvest forage yields (weeds plus alfalfa) were either reduced or unchanged by herbicide treatments. Total forage yield was not altered by the herbicide treatments, but first-harvest and total alfalfa yield as well as first-harvest forage protein content were increased by several treatments, depending on stand density and weed pressure. Little effect was observed on in vitro digestible dry matter or acid detergent fiber content.

scholarly journals Nitrogen Pools in Tropical Plantations of N2-Fixing and Non-N2-Fixing Legume Trees under Different Tree Stand Densities

Nitrogen ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 86-98
Author(s):  
Kelly Nery Bighi ◽  
Ranieri Ribeiro Paula ◽  
Marcos Vinícius Winckler Caldeira ◽  
Diego Lang Burak ◽  
Eduardo de Sá Mendonça ◽  
...  
Keyword(s):  
N2 Fixation ◽  
Stand Density ◽  
N Accumulation ◽  
Biological N2 Fixation ◽  
Nitrogen Acquisition ◽  
Nitrogen Pools ◽  
Acquisition Strategies ◽  
Tropical Plantations ◽  
Schizolobium Parahyba ◽  
Slow Growing

We investigated the nitrogen pools in monocultures of legume species widely used in reforestation in Brazil that have contrasting growth and nitrogen acquisition strategies. The plantations were established with the slow-growing and N2-fixing tree Anadenanthera peregrina var. peregrina, and the fast-growing and non-fixing tree Schizolobium parahyba var. amazonicum. The measurements of N pools in the tree biomass and the soil followed standard methods and were carried out on 54 experimental plots. The N2 fixation pools were evaluated by abundance natural of 15N and the N accretion methods. The soil N content was of similar magnitude between species and stand densities. The species showed similar amounts of N in the biomass, but divergent patterns of N accumulation, as well as the 15N signature on the leaves. S. parahyba accumulated most N in the stem, while A. peregrina accumulated N in the roots and leaves. However, the N accumulation in biomass of A. peregrina stand was less constrained by environment than in S. parahyba stands. The percentage of N derived from N2 fixation in A. peregrina stands decreased with the increase of stand density. The biological N2 fixation estimates depended on the method and the response of tree species to environment.

scholarly journals Irrigation Timing as a Practice of Effective Weed Management in Established Alfalfa (Medicago sativa L.) Crop

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 550
Author(s):  
Panagiotis Kanatas ◽  
Ioannis Gazoulis ◽  
Ilias Travlos
Keyword(s):  
Medicago Sativa ◽  
Weed Management ◽  
Cultural Practices ◽  
Block Design ◽  
Chenopodium Album ◽  
Stand Density ◽  
Climatic Conditions ◽  
Amaranthus Retroflexus ◽  
Forage Yield ◽  
Medicago Sativa L

Irrigation is an agronomic practice of major importance in alfalfa (Medicago sativa L), especially in the semiarid environments of Southern Europe. Field experimentation was conducted in Western Greece (2016–2018) to evaluate the effects of irrigation timing on weed presence, alfalfa yield performance, and forage quality. In a randomized complete block design (four replications), two cultivars (“Ypati 84” and “Hyliki”) were the main plots, while three irrigation timings were the subplots (split-plot). The irrigation timings were IT-1, IT-2, and IT-3, denoting irrigation 1 week before harvest, 1 week after harvest, and 2 weeks after harvest, respectively. IT-1 reduced Solanum nigrum L. density by 54% and 79% as compared to IT-3 and IT-2, respectively. Chenopodium album L. density was the highest under IT-2. IT-3 resulted in 41% lower Amaranthus retroflexus L. density in comparison to IT-2, while the lowest values were observed under IT-1. Stand density and stems·plant−1 varied between years (p ≤ 0.05). Mass·stem−1 and alfalfa forage yield were affected by the irrigation timings (p ≤ 0.001). Total weed density and forage yield were negatively correlated in both the second (R2 = 87.013%) and the fourth (R2 = 82.691%) harvests. IT-1 and IT-3 increased forage yield, leaf per stem ratio, and crude protein as compared to IT-2. Further research is required to utilize the use of cultural practices for weed management in perennial forages under different soil and climatic conditions.

scholarly journals Biotic and Abiotic Determinants of Soil Organic Matter Stock and Fine Root Biomass in Mountain Area Temperate Forests—Examples from Cambisols under European Beech, Norway Spruce and Silver Fir (Carpathians, Central Europe)

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 823
Author(s):  
Anna Zielonka ◽  
Marek Drewnik ◽  
Łukasz Musielok ◽  
Marcin K. Dyderski ◽  
Dariusz Struzik ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Norway Spruce ◽  
Root Biomass ◽  
Fine Root ◽  
Stand Density ◽  
European Beech ◽  
Fine Root Biomass ◽  
Silver Fir ◽  
Beech Forests

Forest ecosystems significantly contribute to the global organic carbon (OC) pool, exhibiting high spatial heterogeneity in this respect. Some of the components of the OC pool in a forest (woody aboveground biomass (wAGB), coarse root biomass (CRB)) can be relatively easily estimated using readily available data from land observation and forest inventories, while some of the components of the OC pool are very difficult to determine (fine root biomass (FRB) and soil organic matter (SOM) stock). The main objectives of our study were to: (1) estimate the SOM stock; (2) estimate FRB; and (3) assess the relationship between both biotic (wAGB, forest age, foliage, stand density) and abiotic factors (climatic conditions, relief, soil properties) and SOM stocks and FRB in temperate forests in the Western Carpathians consisting of European beech, Norway spruce, and silver fir (32 forest inventory plots in total). We uncovered the highest wAGB in beech forests and highest SOM stocks under beech forest. FRB was the highest under fir forest. We noted a considerable impact of stand density on SOM stocks, particularly in beech and spruce forests. FRB content was mostly impacted by stand density only in beech forests without any discernible effects on other forest characteristics. We discovered significant impacts of relief-dependent factors and SOM stocks at all the studied sites. Our biomass and carbon models informed by more detailed environmental data led to reduce the uncertainty in over- and underestimation in Cambisols under beech, spruce, and fir forests for mountain temperate forest carbon pools.

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