Long-term forest utilization can decrease forest floor microhabitat diversity: evidence from boreal Fennoscandia

2004 ◽  
Vol 34 (2) ◽  
pp. 303-309 ◽  
Author(s):  
Timo Kuuluvainen ◽  
Raija Laiho

Forest floor microhabitat diversity was studied in old Pinus sylvestris L. dominated forest sites in two regions within the middle boreal vegetation zone in Fennoscandia: in 50 managed forest sites in the Häme region in southwestern Finland and in 45 natural or old selectively logged forest sites in the Kuhmo–Viena region in northeastern Finland and northwestern Russia. The forests in the Häme region are characterized by a long history of forest utilization, while the forests in the Kuhmo–Viena region can be regarded as natural or near natural. The managed forest sites in Häme had significantly lower forest floor microhabitat diversity compared with natural and near-natural forests. Microhabitats that were significantly more scarce in managed versus natural and near-natural forest sites included humps, depressions, decayed wood, and vicinity of decayed wood. On the other hand, even ground was significantly more abundant in managed forest compared with natural and near-natural forest. Microhabitat availability was also reflected in the occurrence of tree saplings growing in different microhabitats. The results suggest that long-term forest utilization has decreased forest floor microhabitat diversity. This has occurred because of a decreased amount of fallen deadwood and, possibly, lack of soil disturbances because of fewer uprootings caused by falling trees.

2006 ◽  
Vol 36 (12) ◽  
pp. 3239-3245 ◽  
Author(s):  
Marjo Helander ◽  
Piippa Wäli ◽  
Timo Kuuluvainen ◽  
Kari Saikkonen

Fungal endophytes of birch trees are nonsystemic and transmitted horizontally by spores. Because the endophytes reinfect the leaves every growing season, the frequency of occurrence and species composition of the fungi depend on various abiotic and biotic environmental conditions. This was a study of possible effects of silviculture and local environmental variables on endophyte frequencies. Silver birch (Betula pendula Roth) leaves were sampled from seedling stands (five transects), managed mature forest (seven transects), and old natural forest (five transects) in the boreal vegetation zone in east-central Finland. The sapling stands had the highest endophyte frequency and the managed forest the lowest total infection frequency. The old natural forest tended to have the most diverse identified fungal species community, but the difference was not statistically significant. The most frequently isolated endophytic fungi were Fusicladium betulae (Rob. & Desm.) Aderh., consisting of 70% of the isolates from the sapling stands and 31% and 21% of the isolates from the managed forest and natural forest, respectively. It is probable that the sapling stands had plenty of available spores combined with an otherwise favourable microclimate. In the natural forests Gnomonia setacea (Pers.:Fr.) Ces. & de Not. was the most frequently isolated endophyte (30%), while in the sapling stands only 4% of the isolates belonged to G. setacea. In natural forest the frequency of G. setacea infections was positively correlated with stand age, indicating that G. setacea is favouring the old forest habitats.


2007 ◽  
Vol 7 ◽  
pp. 192-197 ◽  
Author(s):  
M. F. Hovmand ◽  
Kaare Kemp

Atmospheric bulk deposition of heavy metals (HM) was measured from 1972/73 to the present time at five to ten forest sites in rural areas of Denmark. From 1979, HM in aerosols were measured at one to four forest sites. On the basis of these long-term continuous measurements, the atmospheric inputs to the forest floor have been calculated. Yearly HM emission estimates to the European atmosphere seems to correlate well with yearly average values of HM deposition, as well as with HM concentrations in the ambient atmosphere. HM emissions have been estimated since the 1950s. Using the correlation between emission and deposition, HM deposition values maybe extrapolated in reverse chronological order. The accumulated atmospheric HM deposition has been estimated in this way over a period of 50 years.


2002 ◽  
Vol 32 (12) ◽  
pp. 2184-2200 ◽  
Author(s):  
S Rouvinen ◽  
T Kuuluvainen ◽  
L Karjalainen

Coarse woody debris (CWD) was studied in old Pinus sylvestris L. dominated forests in three geographic regions in the middle boreal vegetation zone: (i) in Häme in southwestern Finland, characterized by a long history of forest utilization, (ii) in Kuhmo in northeastern Finland, with a more recent history of forest utilization, and (iii) in the Vienansalo wilderness area in northwestern Russia, characterized by large areas of almost natural forest. Within the geographic regions the measured 0.2-ha plots were divided into three stand types according to the degree of human impact: (i) natural stands, (ii) selectively logged stands, and (iii) managed stands. The results showed that compared with natural forests, forest management has strongly reduced both the amount and diversity of CWD. The highest total CWD volumes were found in the natural stands in Häme (mean 67 m3·ha–1) and Kuhmo (92 m3·ha–1) and in the selective logged stands in Vienansalo (80 m3·ha–1), while the lowest CWD volumes were found in the managed stands in Häme (7 m3·ha–1) and Kuhmo (22 m3·ha–1). The duration of forest utilization also plays a role, as forests with short management histories (Kuhmo region) still carried structural legacies from earlier more natural stages of the forest. In addition to lower total CWD volumes, managed stands also largely lacked certain dead wood characteristics, particularly large dead trees and standing dead trees with structural diversity characteristics (such as stem breakage, leaning stems, and fire scars) when compared with natural and selectively logged stands. The CWD characteristics of stands selectively logged in the past were often comparable with those of natural stands, suggesting that old selectively logged stands can be of high value from the nature conservation point of view.


1989 ◽  
Vol 19 (1) ◽  
pp. 69-78 ◽  
Author(s):  
Paula M. Schiffman ◽  
W. Carter Johnson

Carbon in soil, forest floor, and phytomass was estimated for two chronosequences of loblolly pine (Pinustaeda L.) plantations, as well as agricultural fields and natural Virginia pine (P. virginiana Mill.) forests. One plantation chronosequence was initiated on postagricultural fields and the other following clearing of natural second-growth pine forests and site preparation. Natural reforestation of old fields over 50–70 years increased carbon storage by about 235%, from about 55 000 to 185 000 kg/ha. Carbon in phytomass accounted for the greatest proportion of the increase (76%), followed by forest floor (13%) and surface soil (10%). Old field plantations stored more carbon than natural forests by approximately 42 000 kg/ha (22%). Virtually all of the gain was in phytomass. The contemporary practice of converting natural forests to plantations yielded only a modest gain in carbon (24%), and this in phytomass scheduled for harvest, not in detritus. The results showed negligible oxidative losses of carbon from soils after harvest and site preparation. Site preparation which includes burning may actually cause slow but long-term increases in detrital carbon as charcoal. Forest floor losses during conversion are largely regained by rotation end. Global carbon models need to be amended to incorporate these findings. Stabilization of the forest land base in the Piedmont foretells a rapidly declining capacity to store carbon at past rates. In terms of carbon gained, the current practice of converting natural forests to plantations is no substitute for the farm to forest conversions of past decades. Whether the southeastern United States Piedmont will continue to act as a net carbon sink depends largely on the balance between gains in detrital carbon, principally from charcoal produced by repeated site preparation, and the extent to which forest products from highly productive plantations are placed in long-term versus short-term storage.


2020 ◽  
Author(s):  
Byongjun Hwang ◽  
Kitessa Hundera ◽  
Bizuneh Mekuria ◽  
Adrian Wood ◽  
Andinet Asfaw

<p>The high forests in southwest Ethiopia, some of the last remaining Afromontane forests in the country, are home to significant forest coffee production. While considered as beneficial in maintaining forests, there have been growing concerns about the degradation caused by intensive coffee production in the forests. However, yet no suitable methods have been developed to map the intensively managed coffee forests. In this study, we explore the feasibility of monitoring the extent of the degradation within the intensively managed coffee forests by using satellite imagery (Landsat-8 and Sentinel-2). For this, we conducted in-situ field canopy photo and tree surveys, and the results were analysed with satellite-derived vegetation indices such as NDVI and NBR. This feasibility study informed us that the detection of the intensively managed forest coffee areas (disturbances caused by this practice) using satellite imagery can be possible, as the dry-season forest structure (canopy, undergrowth) and vegetation indices in the intensively managed coffee forests are significantly distinctive from those in natural forests. This study will contribute to the long-term sustainable management of the coffee forest.</p>


Land ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 376
Author(s):  
Xinghua Qin ◽  
Cheng Yang ◽  
Lin Yang ◽  
Erdeng Ma ◽  
Lei Meng ◽  
...  

Evaluations of gross mineralization (MNorg) and nitrification (ONH4) can be used to evaluate the supply capacity of inorganic N, which is crucial in determining appropriate N fertilizer application. However, the relevant research for banana plantations to date is limited. In this study, natural forest and banana plantations with different cultivation ages (3, 7, 10, and 22 y) were chosen in a subtropical region, and the 15N dilution technique was used to determine the gross MNorg and ONH4 rates. The objective was to evaluate the effect of the conversion of natural forests to banana plantations on inorganic N supply capacity (MNorg + ONH4) and other relevant factors. Compared to other natural forests in tropical and subtropical regions reported on by previous studies, the natural forest in this study was characterized by a relatively low MNorg rate and a high ONH4 rate in the soil, resulting in the presence of inorganic N dominated by nitrate. Compared to the natural forest, 3 y banana cultivation increased the MNorg and ONH4 rates and inorganic N availability in the soil, but these rates were significantly reduced with prolonged banana cultivation. Furthermore, the mean residence times of ammonium and nitrate were shorter in the 3 y than in the 7, 10, and 22 y banana plantations, indicating a reduced turnover of ammonium and nitrate in soil subjected to long-term banana cultivation. In addition, the conversion of natural forest to banana plantation reduced the soil organic carbon (SOC), total N and calcium concentrations, as well as water holding capacity (WHC), cation exchangeable capacity (CEC), and pH, more obviously in soils subjected to long-term banana cultivation. The MNorg and ONH4 rates were significantly and positively related to the SOC and TN concentrations, as well as the WHC and CEC, suggesting that the decline in soil quality after long-term banana cultivation could significantly inhibit MNorg and ONH4 rates, thus reducing inorganic N supply and turnover. Increasing the amount of soil organic matter may be an effective measure for stimulating N cycling for long-term banana cultivation.


2020 ◽  
Vol 7 (3) ◽  
pp. 147-152
Author(s):  
Salman Ghaffari ◽  
◽  
Mehran Razavipour ◽  
Parastoo Mohammad Amini ◽  
◽  
...  

McCune-Albright Syndrome (MAS) is characterized by endocrinopathies, café-au-lait spots, and fibrous dysplasia. Bisphosphonates are the most prescribed treatment for reducing the pain but their long-term use has been associated with atypical fractures of cortical bones like femur in patients. We present a 23-year-old girl diagnosed with MAS. She had an atypical mid-shaft left femoral fracture that happened during simple walking. She also had a history of long-term use of alendronate. Because of the narrow medullary canal, we used 14 holes hybrid locking plate for the lateral aspect of the thigh to fix the fracture and 5 holes dynamic compression plate (instead of the intramedullary nail) in the anterior surface to double fix it, reducing the probability of device failure. With double plate fixation and discontinuation of alendronate, the complete union was achieved five months after surgery


Author(s):  
Johann P. Arnason

Different understandings of European integration, its background and present problems are represented in this book, but they share an emphasis on historical processes, geopolitical dynamics and regional diversity. The introduction surveys approaches to the question of European continuities and discontinuities, before going on to an overview of chapters. The following three contributions deal with long-term perspectives, including the question of Europe as a civilisational entity, the civilisational crisis of the twentieth century, marked by wars and totalitarian regimes, and a comparison of the European Union with the Habsburg Empire, with particular emphasis on similar crisis symptoms. The next three chapters discuss various aspects and contexts of the present crisis. Reflections on the Brexit controversy throw light on a longer history of intra-Union rivalry, enduring disputes and changing external conditions. An analysis of efforts to strengthen the EU’s legal and constitutional framework, and of resistances to them, highlights the unfinished agenda of integration. A closer look at the much-disputed Islamic presence in Europe suggests that an interdependent radicalization of Islamism and the European extreme right is a major factor in current political developments. Three concluding chapters adopt specific regional perspectives. Central and Eastern European countries, especially Poland, are following a path that leads to conflicts with dominant orientations of the EU, but this also raises questions about Europe’s future. The record of Scandinavian policies in relation to Europe exemplifies more general problems faced by peripheral regions. Finally, growing dissonances and divergences within the EU may strengthen the case for Eurasian perspectives.


2019 ◽  
Author(s):  
Ayesha Shaikh ◽  
Natasha Shrikrishnapalasuriyar ◽  
Giselle Sharaf ◽  
David Price ◽  
Maneesh Udiawar ◽  
...  

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