scholarly journals Synergy in mixed Nothofagus spp. plantations: the effect of deciduous/evergreen neighbourhood on tree growth in the Chilean Andes

2020 ◽  
Vol 50 ◽  
Author(s):  
Patricio Ojeda-González ◽  
Pablo J. Donoso ◽  
Alfredo Erlwein
Keyword(s):  
Tree Growth ◽  
Average Diameter ◽  
Deciduous Tree ◽  
Average Height ◽  
Nonlinear Mixed Effects Models ◽  
Average Volume ◽  
Individual Tree ◽  
Nothofagus Obliqua ◽  
Temperate Rainforests ◽  
Nothofagus Dombeyi

Background: The genus Nothofagus is a key component of the Valdivian temperate rainforests of South America, and several of its species have shown promising growth in plantations. Plantations with these species are an opportunity to diversify the Chilean forest sector, ideally through mixed-species arrangements, but the existing literature in this regard is scarce. This work aimed to evaluate individual tree growth for three Nothofagus species in a mixed plantation, considering two types of neighbourhoods. Methods: In a mid-elevation site in the foothills of the Andes ranges we evaluated growth of Nothofagus alpina (Poepp. & Endl.) Oerst, Nothofagus dombeyi (Mirb.) Oerst and Nothofagus obliqua (Mirb.) Oerst according to their neighbourhood, comprised of evergreen or deciduous tree species. We conducted stem analyses for 30 trees (10 per species, one-half with each type of neighbourhood; 370 cross-sections in total) and compared growth in diameter (d), height (h), and volume (v) for each of the 30 trees with nine nonlinear mixed-effects models. Results: Nothofagus alpina showed significantly greater cumulative growth in all variables when growing in an evergreen neighbourhood (EN) compared with a deciduous neigbourhood (DN): average diameter (± 1SD) of 15.3 ± 1.4 vs. 10.8 ± 2.0 cm; average height (± 1SD) of 15.5 ± 1.8 vs. 13.2 ±1.0 m; average volume (± 1SD) of 0.15 ± 0.05 vs. 0.06 ± 0.02 m3. Nothofagus dombeyi showed similar cumulative growth in both conditions for all variables, but there was less variability and greater cumulative volume in the evergreen neighbourhood condition. Finally, Nothofagus obliqua showed similar cumulative growth in both conditions, for average diameter (± 1SD) (14.7 ± 2.0 cm) and average volume (± 1SD) (0.01 ± 0.03 m3), but the average height (± 1SD) was significantly greater in the EN compared to DN (13.8 ± 0.8 vs. 11.2 ± 0.9 m). Conclusions: A suitable arrangement of mixed Nothofagus species plantations may deliver greater growth and productivity than pure plantations, or at least greater timber value considering that one species (N. dombeyi) usually surpasses the others in growth, but its timber is less valuable and its silviculture more costly. In these mixtures both facilitation and complementarity mechanisms occur, which was mostly expressed in the mid-tolerant N. alpina surrounded by the evergreen neighbourhood dominated by the shade-intolerant N. dombeyi. Our results provide new information relevant for the establishment of mixed plantations for production or restoration purposes. Both in Chile and Argentina, these three Nothofagus species cover extensive areas within the Valdivian Temperate Rainforests, so there is a great potential for these plantations in this or other regions with similar site conditions.

Planting density and tree-size relations in coast Douglas-fir

1998 ◽  
Vol 28 (1) ◽  
pp. 74-78 ◽  
Author(s):  
William Scott ◽  
Rodney Meade ◽  
Richard Leon ◽  
David Hyink ◽  
Richard Miller
Keyword(s):  
Tree Growth ◽  
Stand Density ◽  
Average Diameter ◽  
Douglas Fir ◽  
Planting Density ◽  
Practical Significance ◽  
Average Height ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Initial Spacing

Test plantations were established in western Washington and Oregon to compare tree growth at six initial planting densities ranging from 300 to 2960 trees/ha (120 to 1200/acre). A size-density relation was visually apparent 3 to 4 years after planting. Inventory data from the oldest 11 trials (5 or 6 years after planting) showed that initial spacing strongly influenced early growth of coast Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii). Average height and diameter at breast height were progressively larger as planting density increased; at the widest spacing (lowest stand density), average height was 75% and average diameter at breast height was 67% of that at the closest spacing. We have no firm explanation for the early faster tree growth at close spacings. Trees planted at 2960 trees/ha (1200 trees/acre) attained breast height (1.3 m) 2 years earlier than trees planted at a density of 300/ha (120/acre). This finding has practical significance to current efforts to achieve early establishment of plantations.

scholarly journals Bionomics of Melipona mondury Smith 1863 (Hymenoptera: Apidae, Meliponini) in relation to its nesting behavior

2015 ◽  
Vol 15 (3) ◽  
Author(s):  
Jaqueline Lemos Viana ◽  
Henrique de Abreu Cerqueira Sousa ◽  
Rogério Marcos de Oliveira Alves ◽  
Derval Gomes Pereira ◽  
Juvenal Cordeiro Silva Jr. ◽  
...  
Keyword(s):  
Sustainable Management ◽  
Native Species ◽  
Average Diameter ◽  
Average Height ◽  
Nest Architecture ◽  
Average Volume ◽  
Average Mass ◽  
Support Strategies ◽  
Average Size

Melipona mondury Smith 1863 is an important stingless bee species pollinator and honey/pollen producer, but threatened by fragmentation of habitats throughout its range. This article presents the identification and partial characterization of nesting substrates, bionomic including population features of M. mondury by comparing data between nest architecture of natural beehive and boxes colonies. Nineteen colonies (13 in boxes and six in beehives) were analyzed with regards to substrate nesting, nest characteristics (e.g. length and width of the combs, height and diameter of the pollen and honey jar) and bee population. The average volume and diameter of the trunks cavities used for nesting of M.mondury were18.4 L and 15.8 cm; the average number of combs was 9.26; the average diameter and height of the honey pots were 2.81 cm and 3.29 cm, and the average volume of honey stored was 15.85 mL; the average height and diameter of pollen pots was 3.21 cm and 2.93 cm, respectively, while the average mass of pollen deposited was equal to 12.56 g. The population ranged from 3537 to 10281 individuals between colonies. The results suggest that the conservation of M. mondury should involve reforestation with native species from Atlantic Forest, and the dimensions of boxes should be based on the average size of the nests in the natural environment in order to support strategies of conservation and sustainable management of this species.

scholarly journals Altersstruktur und Wachstum anhand geworfener Bäume auf einer Windwurffläche im Waldreservat Bödmeren | Estimation of Age Structure and Growth Patterns on a Windthrow Area in the Bödmeren Forest Reserve

2001 ◽  
Vol 152 (2) ◽  
pp. 61-70 ◽  
Author(s):  
Josef Gabriel ◽  
Otto Ulrich Bräker ◽  
Jean-François Matter
Keyword(s):  
Age Structure ◽  
Growth Dynamics ◽  
Average Diameter ◽  
Growth Patterns ◽  
Age Difference ◽  
Average Height ◽  
Height Increment ◽  
Individual Tree ◽  
Forest Reserve ◽  
The Individual

The forest reserve Bödmeren near Muotathal in the canton of Schwyz, Switzerland, covers an area of 4.8 ha and is situated between 1200 and 1500 m a.s.l. It was established in 1971 and the terms of utilisation were drawn up in a contract with the proprietors of the ‹Oberalmeind Corporation›. The forest reserve serves as a multidisciplinary study area in which research of the natural succession without the influences of silvicultural treatment is conducted. In February 1990, a severe storm threw trees on an area of approx. 20 a, allowing a preliminary study to assess the age structure and growth patterns of small clusters of trees. The difference of the pith age of the 27 studied trees covered a range of 120 years, and contrary to expectations, the age difference of 24 trees was only 53 years. The trees were selected from 7 clusters and included all tree stages from the dominant tree to the suppressed tree. The b.h.d. ranged between 19.9 and 72.4 cm even though the age span within the cluster itself and amongst the clusters was generally small. The social position of the individual tree is usually reflected in the height as well as in the diameter growth pattern. The growth dynamics of a suppressed tree can change considerably during its lifetime: a tree was found to be the smallest in the cluster at the age of 20 years and then improved its position in the next 30 years to one of above average height and diameter. The average diameter increment at breast height culminated in the first decade and then decreased continuously. The height increment in the first two decades was restrained: the trees needed 16 years to attain a height of 1.3 m. After this period the individual height increment varied according to the competitional situation. Even though a cluster was dense, the dominated trees retained their vitality to an old age. The average height increment culminated at the age of 50 years.

scholarly journals Productivity of harvesting and clearing of brushwood alongside forest roads

Silva Fennica ◽  
2020 ◽  
Vol 54 (5) ◽  
Author(s):  
Juha Laitila ◽  
Kari Väätäinen
Keyword(s):  
Management Practices ◽  
Average Diameter ◽  
Strong Impact ◽  
Average Volume ◽  
Time Consumption ◽  
Roadside Vegetation ◽  
Study Results ◽  
Cost Efficient ◽  
The Cost ◽  
Stump Diameter

Expertise in the cost-efficient utilization and treatment of brushwood on forest roadside sites is limited. In the present study, the productivity of brushwood clearing and harvesting on forest roadside sites was defined by creating time-consumption models or parameters for the aforementioned working methods. Compiled time consumption models and parameters for the brushwood clearing and harvesting can be used as a basis for evaluating alternative management practices and to determine when brushwood biomass should be harvested and when it should be left to decay. The harvesting of brushwood was based on the harwarder system and the clearing of brushwood was done with a spiral cutter, which is a novel accessory for cutting roadside vegetation. Based on the study results, the average volume of harvested brushwood and forwarding distance are the key elements that have an effect on harvesting productivity with harwarders. Correspondingly, stump diameter has a strong impact on the clearing productivity of brushwood. The plot-wise productivity of the spiral cutter in brushwood clearings varied in the range of 0.19–0.61 ha per PMh. An increase in stump diameter slowed down the clearing productivity of the spiral cutter and there was a clear step downward in clearing productivity as the average diameter increased from 30 mm to 40 mm. The machinery under study operated well and there were no interruptions due to machine breakdowns.

scholarly journals Entwicklung klimasensitiver Wachstumsfunktionen für das Szenariomodell «Massimo»

2015 ◽  
Vol 166 (6) ◽  
pp. 389-398 ◽  
Author(s):  
Brigitte Rohner ◽  
Esther Thürig
Keyword(s):  
Tree Ring ◽  
Tree Growth ◽  
Tree Species ◽  
Climatic Factors ◽  
Climate Variables ◽  
Individual Tree ◽  
Climate Effects ◽  
Growth Functions ◽  
Tree Ring Data ◽  
Scenario Model

Development of climate-dependent growth functions for the scenario model “Massimo” Tree growth is substantially influenced by climatic factors. In the face of climate change, climate effects should therefore be included in estimations of Switzerland's future forest productivity. In order to include climate effects in the growth functions of the “Massimo” model, which is typically applied to project forest resources in Switzerland, we statistically modelled climate effects on tree growth representatively for Switzerland by simultaneously considering further growth-influencing factors. First, we used tree ring data to evaluate how climate variables should be defined. This analyses showed that for modelling multi-year tree growth we should use averages of whole-year variables. Second, we fitted nonlinear mixed-effects models separately for the main tree species to individual-tree growth data from the Swiss National Forest Inventory. In these models, we combined climate variables defined according to the results of the tree ring study with various further variables that characterize sites, stands and individual trees. The quantified effects were generally plausible and explained convincingly the physiological differences between the species. The statistical growth models for the main tree species will now be included in the forest scenario model “Massimo”. This will allow for founded analyses of scenarios which assume changing climatic conditions.

The impact of drought on tree growth in Mediterranean sites

2021 ◽  
Author(s):  
Giovanna Battipaglia ◽  
Francesco Niccoli ◽  
Arturo Pacheco-Solana
Keyword(s):  
Climate Change ◽  
Tree Growth ◽  
Sustainable Forest Management ◽  
Climatic Factors ◽  
Management Strategies ◽  
Ring Width ◽  
Limiting Factor ◽  
Individual Tree ◽  
Annual Growth Rings ◽  
The Impact

<p>Climate-induced forest mortality is a critical issue in the Mediterranean basin, with major consequences for the functioning of these key ecosystems. Indeed, in Mediterranean ecosystems, where water stress is already the most limiting factor for tree performance, climatic changes are expected to entail an increase in water deficit. In this context, annual growth rings can provide short- (e.g., years) and long-term (e.g., decades) information on how trees respond to drought events. With climate change, <em>Pinus pinaster</em> and <em>Pinus pinea</em> L. are expected to reduce their distribution range in the region, being displaced at low altitudes by more drought tolerant taxa such as sub Mediterranean <em>Quercus</em> spp.</p><p>This study aims was to assess the physiological response of <em>Pinus</em> and <em>Quercus</em> species growing in the Vesuvio National park, located in Southern Italy and where an increase of temperature and drought events has been recorded in the recent years. Our preliminary results underlined the importance of temperature on the tree ring width of all the analyses species. The high temperatures can cause a change in the constant kinetics of the RuBisCo, leading to a consequent decrease in carboxylation rate and thus to a reduction in tree growth. On the other hand, also precipitation seemed to affect the growth of the sampled trees: indeed, in all the chronologies a reduction in growth was found after particular dry years: for example, the low rainfall in 1999 (455 mm/year) determined a drastic decline in growth in 2000 in all the species. In addition to the climatic factors, competition can also play an important role in the growth rate: dendrochronological analyzes have highlighted how stand specific properties (i.e. density, structure and composition) can influence individual tree responses to drought events. The knowledge of those researches should be integrated into sustainable forest management strategies to minimize the potential impacts of climate change on forest ecosystems.</p>

scholarly journals Influence of Planting Density on Diameter and Height in East Texas Pine Plantations

1998 ◽  
Vol 22 (4) ◽  
pp. 241-244 ◽  
Author(s):  
Young-Jin Lee ◽  
J. David Lenhart
Keyword(s):  
Average Diameter ◽  
Pinus Elliottii ◽  
Pine Plantations ◽  
Planting Density ◽  
Permanent Plots ◽  
Average Height ◽  
East Texas ◽  
Age Classes ◽  
Younger Age ◽  
Pinus Taeda L

Abstract The response of diameter and height of unthinned planted stands loblolly (Pinus taeda L.) and slash (Pinus elliottii Engelm.) pine in East Texas to different classes of planting densities were analyzed. After tracking the development of diameter and height for 15 yr on a set of permanent plots representing a broad range of plantation parameters, average diameter and average height trends were observed. For both species, average diameter values were significantly larger with lower planting densities. In contrast, average height growth is insensitive to planting density at younger age classes for loblolly and at older age classes for slash pine plantations. South. J. Appl. For. 22(4):241-244.

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