scholarly journals Slenderness of trees in black locust stands

2018 ◽  
Vol 79 (2) ◽  
pp. 113-117
Author(s):  
Szymon Bijak ◽  
Katarzyna Orzoł

Abstract This paper investigates the slenderness of black locust (Robinia pseudoacacia) trees in relation to the biosocial status of the trees, stand age class, crown parameters and habitat type. The research material was collected on 35 research plots in the Sława Śląska, Sulechów and Głogów forest districts in western Poland and comprises 1058 trees. For each tree, we measured height (h) as well as diameter at breast height (d) and determined its biosocial status (Kraft class), crown length (CL) and relative crown length (rCL). The age class and habitat type were assessed at the plot level. Because the obtained values for slenderness (s=h/d) diverged significantly from the normal distribution, we used Kruskal-Wallis and Mann-Whitney tests to investigate the influence of the above-mentioned parameters on the h/d ratio. Black locust slenderness ranged from 0.31 to 1.95 with an average of 0.91 (standard deviation 0.24). It furthermore differed significantly between Kraft classes (the higher the biosocial status, the lower the slenderness) and age classes (the older the trees, the lower their slenderness). We also found a significant effect of the habitat type (in oligotrophic sites trees formed more slender trunks than in mesotrophic sites) and crown parameters on the h/d ratio (decreasing with increasing crown length and relative crown length). The obtained results suggest that the slenderness of black locust does not differ substantially from native broadleaved trees in Poland.

2014 ◽  
pp. 9-31
Author(s):  
Sinisa Andrasev ◽  
Savo Roncevic ◽  
Petar Ivanisevic ◽  
Sasa Pekec ◽  
Martin Bobinac

This paper presents the elements of growth of black locust trees and stands in 15 sample plots in Vojvodina, at the age of 21-68 years. In each sample plot, based on soil profile horizons the determined soil type was chernozem as well as its lower systematic units (subtype, variety and form), according to the Skoric et al. (1985) classification. On the basis of the mean stand heights (hL), the stands on the subtype of chernozem on loess and loesslike sediments belong to height classes I-IV, and stands on calcareous aeolian sand to classes II-V (according to R e d e i et al. 2014), which indicates their considerable variability with respect to productivity within the determined subtypes of chernozem. Significant differences at the level of chernozem subtypes were found between the mean heights (p = 0.032), but not between the mean diameters (p = 0.083). The mean diameters at breast height in the studied black locust stands were on average lower than the models of diameter growth for the appropriate height classes and determined by a larger number of trees per hectare than in the tables (R e d e i et al, 2014). The volume per hectare is higher than in the tables also being conditioned by the large number of trees per hectare.


2018 ◽  
Vol 169 (2) ◽  
pp. 77-85 ◽  
Author(s):  
Michaela Vítková ◽  
Marco Conedera ◽  
Jiří Sádlo ◽  
Jan Pergl ◽  
Petr Pyšek

Dangerous and useful at the same time: management strategies for the invasive black locust The North American black locust (Robinia pseudoacacia) is considered controversial as many other introduced tree species because of its both positive and negative properties. Based on a literature review and own data we analyze the occurrence of black locust in Czechia and Switzerland and present the management approaches in place. In both countries, black locust is on the blacklist of invasive introduced species. It can grow in a wide range of habitats from urban and agricultural landscape to dry grassland and forest. Meanwhile, the species became in many places part of the environment and human culture, so that neither unrestricted cultivation nor large-scale eradication is feasible. We suggest a context-dependent management which respects the different needs and takes into account the local environmental conditions, land-use, habitat type, risk of spread as well as economic, cultural and biodiversity aspects. To this purpose we propose three management strategies: 1) control respectively gradual suppression of black locust in forests where the species is not welcome, 2) its eradication in sensitive ecosystems as dry grasslands or clear and dry forests and 3) its tolerance in intensively managed agricultural landscapes and in urban environment.


Forests ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 261 ◽  
Author(s):  
Jian Deng ◽  
Sha Wang ◽  
Chengjie Ren ◽  
Wei Zhang ◽  
Fazhu Zhao ◽  
...  

Plant nitrogen (N) and phosphorus (P) resorption is an important strategy to conserve N and P in the face of nutrient limitation. However, little is known about the variation of N and P resorption efficiency (NRE and PRE) and their correlation with leaves and soil C:N:P stoichiometry in black locust forests (Robinia pseudoacacia L.) of different ages. In this study, we measured C, N, and P concentrations in soil, green leaves, and senesced leaves from black locust forests of different ages (i.e, 10-, 20-, 30-, 36-, and 45-year-old), and calculated the NRE, PRE, and C:N:P stoichiometry ratios. The NRE and PRE tended to increase and then decrease with stand age, ranging from 46.8% to 57.4% and from 37.4% to 58.5%, with averages of 52.61 and 51.89, respectively. The PRE:NRE decreased with increased stand ages. The C:P and N:P of soil and green leaves increased with stand ages, indicating the increase of P limitation. In the senesced leaves, C:P and N:P were lower than in green leaves and first increased and then decreased with stand age. The PRE was significantly negatively correlated with the C:P and N:P of soil and green leaves. The NRE was significantly correlated with the C concentration of green leaves, P of the senesced leaves, and C:N. Results suggested that the NRE and PRE responded differently to soil and plant nutrients in black locust forests of different ages. In addition, the black locust plantations would alter the conservation and use strategy of nutrients in the ecosystem through a plant-mediated pathway. Future studies should elucidate the central nutrient utilization strategy of black locust in response to a nutrient-poor environment and determine how it is involved in regulating nutrient resorption.


1983 ◽  
Vol 7 (1) ◽  
pp. 27-30 ◽  
Author(s):  
Charles E. Rowell ◽  
Stanley B. Carpenter

Abstract Regression equations to predict dry weight of above-ground biomass are developed from a sample of 1,371 trees collected in 130 direct-seeded black locust (Robinia pseudoacacia L.) stands on ten reclaimed surface mines in the Cumberland Plateau region of eastern Kentucky. Equations using the log 10 transformation of diameter squared times height were derived for each of the one- to ten-year age classes within the sample. Two equations were selected that best estimated woody biomass of trees after consolidating the one- to four-year and five- to ten-year age classes. An equation was also provided that encompasses all age classes; however, the estimation of individual tree woody biomass was not as representative as was the value provided by each of the two separate equations.


2018 ◽  
Vol 64 (No. 2) ◽  
pp. 96-100 ◽  
Author(s):  
Rédei Károly ◽  
Bakti Beatrix ◽  
Kiss Tamás ◽  
Takács Marianna ◽  
Keserű Zsolt

The paper provides the results of a detailed analysis of timber volume and the most important crown variables of black locust (Robinia pseudoacacia Linnaeus) based on an experimental plot in southern Hungary. At the age of 20 years the crop trees belonged to different height classes. If the volume of the mean tree from height class I is considered as 100%, the volume of the mean tree of class II is 44.0%, and the mean tree of class III is only 30.3%. In case of timber volume per 1 m<sup>2</sup> crown surface, the values are 72.9 and 61.7%. The DBH of trees showed a positive linear correlation with crown diameter (r = 0.942). Additionally, there were also positive linear relationships between crown diameter and volume (r = 0.901), between crown length and volume (r = 0.721) as well as tree height and crown length (r = 0.661). The variation of crown indices is height even within the same stand and indicates the importance of following a selective thinning operation method.


2006 ◽  
Vol 84 (3) ◽  
pp. 363-370 ◽  
Author(s):  
Imre Cseresnyés ◽  
Péter Csontos ◽  
Erika Bózsing

In Hungary, plantations of Pinus nigra Arn. (Austrian pine) involve large areas of dolomite rock grasslands and have caused the impoverishment or local extinction of the original flora. In addition to these conservation concerns, an important economic problem is the flammability of these forests. Fire risk depends on the amount of accumulated flammable organic components. Thus, the purpose of our research was to quantify the mass of litter accumulated in Austrian pine stands and to examine the correlation between litter mass, stand age, and slope aspect. Forty-eight sampling sites were selected with stand ages ranging from 21 to 108 years. Stands represented four age classes and three exposure types. At each sampling site, litter mass was determined in the following three fractions: needles, branches, and cones. The litter fractions showed their maximum quantities in age class 61–80 years (needles = 17 560 kg/ha, branches = 2764 kg/ha, and cones = 2960 kg/ha). For the needle litter, a significant increase with age was detected through the age classes of 21–40, 41–60, and 61–80 years, and then a significant decrease occurred in stands above 80 years. In the case of branch litter, the age-dependent increase was again significant to its maximum quantity, but the decrease in old stands proved to be insignificant. With cone litter, age dependence could not be detected. Exposure of the stands had no effect on the quantities of the three litter fractions. The amount of accumulated litter of Austrian pine stands many times exceed the litter quantity of the rock grasslands (the original vegetation prior to afforestation). Furthermore, it is two or three times higher than the amount of litter reported from native zonal forests of Hungary. Therefore, the Austrian pine stands are subjected to an increased risk of fire, especially in age class 61–80 years.


2018 ◽  
Vol 48 (10) ◽  
pp. 1148-1158 ◽  
Author(s):  
Zhongdian Zhang ◽  
Mingbin Huang ◽  
Yongkun Zhang

To examine the spatiotemporal characteristics of the distribution of fine-root area and its relationship with stand age and environmental factors in black locust (Robinia pseudoacacia L.) on the Chinese Loess Plateau, black locust stands were selected at four sites along a precipitation gradient. Four stands of different ages and a transect along the hillslope were also selected at one of the sites. With increasing stand age, fine-root area at the tree level increased exponentially, and the rooting pattern tended to be deeper for trees up to 15 years old and then shallower thereafter. The temporal changes of fine-root distribution could be quantified using stand age and soil nutrients. At the hillslope scale, fine-root area index (FRAI) was lower while the rooting pattern was deeper in the middle slope than in the upper and lower slopes, and the fine-root distribution could be quantified using elevation and soil properties. At the regional scale, FRAI decreased substantially while exhibiting similar rooting patterns with decreasing soil water and nutrient availability along the precipitation gradient. Humidity index represented the regional environmental variation and could be used to quantify FRAI. These findings will be helpful for improving quantification of fine roots and enhancing the accuracy of ecohydrological models.


2021 ◽  
Vol 27 ◽  
pp. 106-109
Author(s):  
K. Rédei ◽  
T. Ábri

The study on the diameter and volume increment of black locust (Robinia pseudoacacia L.) stand (age 10-27 years, yield class II) have shown that in comparison to the periodic annual increment of the breast height diameter of tree in height class I, trees in height class II have reached 83.3%, while in class III only 43.9. The same relations for volume were found 59.0% and 24.5%, respectively. The mean values of the whole stand were close to those of height class II. According to the distribution of the periodic annual increment of volume between 10 and 27 years of age, 50% of the values were between 2.00 and13.88 dm3, 73% were between 2.00 and19.82 dm3, and 96% were between 2.00 and 37.64 dm3. The range of 13.88–19.82 dm3 had the highest occurrence (24.5%).


Forests ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 958
Author(s):  
Jyrki Hytönen

Growing of dense, naturally regenerated downy birch stands using rotations of 24–26 years has been shown to be profitable. Coppicing would be a low-cost regeneration method, however, knowledge on the development of birch coppices is scarce. The height, stem number, and biomass development of sprouts originating from six clearcut stands in three age classes (A: 10–12 years, B: 15–16 years, C: 22–24 years) located in northern Finland was studied. Equations for estimating the aboveground biomass from height were developed for sprouts. The number of sprouts, and their height and biomass were measured annually during nine growing seasons. In addition, sprout damage was assessed. The number of sprouts per hectare was highest in the youngest age class (A) throughout the study period, even though the decrease in the number of stems due to self-thinning was also fastest (from 591,000 sprouts per ha to 105,000 sprouts per ha). The stand age class did not have an effect on either the mean (2.7 m) or dominant height (5.4 m) of birch sprouts. The total leafless above-ground biomass, the mean annual increment (MAI), and the current annual increment (CAI) were highest in the youngest stand age class (A) and lowest in the oldest age class (C). After 9 years, the biomass in the oldest age class was 15.1 Mg ha−1 and 31.1 Mg ha−1 in the youngest age class. During the first six years, the biomass of the sprouts correlated with the number of stumps. A higher number of stumps produced more sprouts and biomass in the first years. However, due to faster self-thinning in the densest stands and higher mass of average sprout in the oldest stands, the correlation between the number of stumps and biomass decreased with the increase of age so that it was no longer significant in years 7, 8, and 9. In the older stand age classes, the MAI increased with the increase of the age of sprouts. The CAI varied considerably between the study years. The study showed that due to coppice vigor, growth of the birch sprouts can be high.


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