The influence of overstorey Populus on epiphytic lichens in subboreal spruce forests of British Columbia

2010 ◽  
Vol 40 (1) ◽  
pp. 143-154 ◽  
Author(s):  
Jocelyn Campbell ◽  
Gary E. Bradfield ◽  
Cindy E. Prescott ◽  
Arthur L. Fredeen

The composition and abundance of lichen communities on conifer saplings beneath five overstorey tree species were compared at three subboreal forest site types in east-central British Columbia. Site-level differences in lichen communities were attributed to different levels of moisture and light limitations in the understorey. At sites with adequate moisture and light, cyanolichens were uniformly abundant and species rich on conifer saplings beneath different understorey species. However, at sites with moisture or light limitations, cyanolichens were more abundant and species rich on conifer saplings beneath overstorey Populus than on saplings beneath other overstorey tree species. Cyanolichen communities also showed greater species richness on conifer saplings beneath the Populus canopy than on the trunk of Populus itself. Differences in calcium, phosphorus, molybdenum, and manganese availability in throughfall precipitation failed to explain much of the variation in lichen community structure. These results suggest that Populus can facilitate cyanolichens under sub optimal moisture or light conditions by providing some, as yet unknown, factor that is critical to their establishment and growth.

2019 ◽  
Vol 170 (6) ◽  
pp. 326-337
Author(s):  
Barbara Huber ◽  
Päivi Gubelmann ◽  
Andreas Zischg ◽  
Sabine Augustin ◽  
Monika Frehner

Modelling of the vegetation belts and the areas of beech and silver fir for Switzerland The vegetation belts and the distribution area of beech and silver fir in Switzerland are an essential basis for the classification of forest site types with ecograms and therefore for site-specific recommendations of tree species and for forestry. Their limits, which are to a large extend defined by climatic factors, were until now only defined on a qualitative basis. For the future usage of the ecograms for tree species recommendations the limits must be described quantitatively, so that they can be modelled for the future with climate scenarios. With maps in a high spatial resolution of the forest-relevant climate variables and with additional important site parameters, those parameters were selected, which were relevant for the actual limits of the vegetation belts as well as for the beech and silver fir areal. The altitudinal belts were modelled by means of a linear regression between the known position of a representative altitudinal limit and the respective climatic factors at that position. The areal limits were modelled with a fuzzy logic approach. The climatic variables for the time span 2070–2099 were calculated on the basis of the climate (emission) scenario A1B (regional models RegCM3 and CLM), so that the limits of the altitudinal belts and the areas could be modelled for the future. The results of the model approaches are ecologically plausible. This could be shown in a comparison with the forest site types on the sample points of the National Forest Inventory and in an expert evaluation. The developed vegetation and climate maps as well as the modelled projections of the altitudinal belts in the future are the basis for the inclusion of climate change in the recommendation of tree species. They serve as decision support for forest managers and authorities in the forestry planning which is confronted with many uncertainties.


2011 ◽  
Vol 41 (12) ◽  
pp. 2337-2345 ◽  
Author(s):  
N. Arhipova ◽  
T. Gaitnieks ◽  
J. Donis ◽  
J. Stenlid ◽  
R. Vasaitis

Root and butt rot is the most destructive disease of conifers in the Northern Hemisphere, but little is known about the dynamics of yield loss in stands of different ages, site types, and species composition. This study aimed to estimate butt rot incidence, causal fungi, and related wood yield loss in Picea abies (L.) H. Karst. stands in Latvia. A total of 24 745 stumps were examined on 318 forest sites, and 21.8% of them contained rot. There was a positive correlation between stand age and butt rot frequency. Proportion of other tree species in a stand had no influence on incidence of the rot, but significant differences were observed among different forest site types. The length of decay columns in 114 stems analysed was 6.6 ± 2.6 m on average. Based on the observed butt rot frequencies in Latvian P. abies stands of different age classes, volumes of decay-degraded wood in a fully stocked stand would comprise about 19.7 m3·ha–1 at the age of 40 years, 57.4 m3·ha–1 at 60 years, 54.9 m3·ha–1 at 80 years, 63.1 m3·ha–1 at 100 years, and 91.8 m3·ha–1 at 120 years, corresponding to 6%–16% of a total standing volume.


1984 ◽  
Vol 60 (2) ◽  
pp. 77-85 ◽  
Author(s):  
K. Klinka ◽  
M. C. Feller

Selecting the best tree species for reforesting a forest site is a critical decision in forest management. Ideally, this decision requires that the ecological characteristics of forest trees, sites and ecosystems are known, and that the intent, goal, strategy and objective of forest management are defined. This knowledge can then be used to develop criteria for selecting the most suitable tree species or combination of tree species for a given site. The criteria used in the tree species selection guidelines for southwestern British Columbia are: maximum sustainable productivity, crop reliability and silvicultural feasibility.


Author(s):  
Maame Esi Hammond ◽  
Radek Pokorný ◽  
Daniel Okae-Anti ◽  
Augustine Gyedu ◽  
Irene Otwuwa Obeng

AbstractThe positive ecological interaction between gap formation and natural regeneration has been examined but little research has been carried out on the effects of gaps on natural regeneration in forests under different intensities of disturbance. This study evaluates the composition, diversity, regeneration density and abundance of natural regeneration of tree species in gaps in undisturbed, intermittently disturbed, and disturbed forest sites. Bia Tano Forest Reserve in Ghana was the study area and three gaps each were selected in the three forest site categories. Ten circular subsampling areas of 1 m2 were delineated at 2 m spacing along north, south, east, and west transects within individual gaps. Data on natural regeneration < 350 cm height were gathered. The results show that the intensity of disturbance was disproportional to gap size. Species diversity differed significantly between undisturbed and disturbed sites and, also between intermittently disturbed and disturbed sites for Simpson’s (1-D), Equitability (J), and Berger–Parker (B–P) indices. However, there was no significant difference among forest sites for Shannon diversity (H) and Margalef richness (MI) indices. Tree species composition on the sites differed. Regeneration density on the disturbed site was significantly higher than on the two other sites. Greater abundance and density of shade-dependent species on all sites identified them as opportunistic replacements of gap-dependent pioneers. Pioneer species giving way to shade tolerant species is a natural process, thus make them worst variant in gap regeneration.


2016 ◽  
Vol 11 (2) ◽  
pp. 466-476
Author(s):  
Bijendra Lal ◽  
L.S. Lodhiyal

Present study deals with stand structure, biomass, productivity and carbon sequestration in oak dominated forests mixed with other broad leaved tree species. The sites of studied forests were located in Nainital region between 29058’ N lat. and 79028’ E long at 1500-2150 m elevation. Tree density of forests ranged from 980-1100 ind.ha-1. Of this, oak trees shared 69-97%. The basal area of trees was 31.81 to 63.93 m2 ha-1. R. arboreum and Q. floribunda shared maximum basal area 16.45 and 16.32 m2 ha-1, respectively in forest site-1 and 2 while Quercus leucotrichophora shared maximum (35.69 m2 ha-1) in site-3. The biomass and primary productivity of tree species ranged from 481-569 t ha-1 and 16.9-20.9 t ha-1yr-1, respectively. Of this, biomass and primary productivity of oak tree species accounted for 81 to 95 and 78 to 98%, respectively. Carbon stock and carbon sequestration ranged from 228 to 270 t ha-1 and 8.0 to 9.9 t ha-1yr-1, respectively. The share of oak tree species ranged from 81 to 94.7 and 79 to 97%, respectively. The diversity of tree species ranged from 0.03 to 0.16 in forest sites-1, 2 and 3. The diversity of oak species was 0.08-0.16 in all the forest sites. Thus it is concluded that among the oak tree species, Quercus floribunda and Quercus leucotrichophora were highly dominated in the studied forests. The climax form of oak dominated trees in the studied forest sites depicted slightly lower richness and diversity of tree species compared to the forests in the region and elsewhere. As far as dry matter and carbon of forests is concerned, these estimates are close to the earlier reports of forests in the region. Therefore, studied forests have the potential to increase the diversity, productivity and carbon sequestration of forest tree species by providing the adequate scientific conservation and management inputs.


Author(s):  
Пуряев ◽  
Aynur Puryaev ◽  
Мифтахов ◽  
Timur Miftakhov ◽  
Демаков ◽  
...  

The objectives of economic assessment of forests, growing on rich soil and environmental conditions, are especially important for the Republic of Tatarstan, as forest site conditions are presented, mostly, fresh suramens and sudubravas. The aim is to develop an algorithm and a mathematical model of the tax and market value dynamics of stands, needed to justify the choice of target tree species. The object of the study is served as detached electronic database of forestry and forest taxation indices of Kama region, general commodity tables and rate per unit volume of standing wood. The methodology of the study was consistent sort and organize raw data on the studied parameters, as well as the drawing up of mathematical models of the dynamics of the studied parameters. According to the research rezults the algorithm of selecting the target tree species was developed, providing the highest economic benefit in cultivation. The pine stands are most profitable to grow at fresh suramens and oak forests at fresh sudubravas. Age of stand’s economic maturity, which occurs at the climax moment of values of mean annual increment of its tax value, is much lower for most tree species, than the established standard terms of logging.


2021 ◽  
Author(s):  
Annette Debel ◽  
Achim Bräuning

&lt;p&gt;Latest drought events and their already visible damage to trees highlight the crucial need to assess the current state and resilience of forest ecosystems in southern Germany. However, commonly applied dendroclimatic approaches rarely take into account, how weather patterns affecting trees are modified by topographic conditions. For this purpose, three main tree species were studied at three low mountain ranges and three corresponding basins in the topographically complex province of Bavaria (southeast Germany). A response analysis between climate proxies and tree-ring widths was used to investigate climate-growth relationships over the past 50 years of both coniferous and deciduous tree species at each forest site. Temporal stability of tree responses to climate was compared for two 25-year periods to detect possible modifications in climate-growth correlations. A pointer year analysis was also conducted to analyze tree response to climatic extreme events. The results showed that Scots pine (&lt;em&gt;Pinus sylvestris&lt;/em&gt;) was the most vulnerable and least drought-resistant of the investigated tree species. Although Norway spruce (&lt;em&gt;Picea abies&lt;/em&gt;) and European beech (&lt;em&gt;Fagus sylvatica&lt;/em&gt;) benefited from an extended growing season at high elevation sites, they showed higher drought sensitivity over the past 25 years. Beech responses were rather inhomogeneous and even differed in the optimal precipitation period. However, lower correlation coefficients for summer precipitation at the driest site may indicate the ability of beech to adapt to less summer precipitation. Nevertheless, increasing drought frequency, as predicted, poses a serious threat to all studied tree species, including even the colder and more humid sites. Hence, to more accurately estimate risk potentials under future weather conditions, we will combine dendroclimatological results with climate modelling scenarios, particularly expected future frequencies of critical weather types on the local scale.&lt;/p&gt;


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