scholarly journals Short- and long-term natural regeneration after windthrow disturbances in Norway spruce forests in Bulgaria

2018 ◽  
Vol 11 (5) ◽  
pp. 675-684 ◽  
Author(s):  
N Tsvetanov ◽  
A Dountchev ◽  
M Panayotov ◽  
P Zhelev ◽  
P Bebi ◽  
...  
Keyword(s):  
Norway Spruce ◽  
Natural Regeneration ◽  
Spruce Forests ◽  
Short And Long Term

Natural regeneration and vegetation changes in wet spruce forests after natural and artificial disturbances

2007 ◽  
Vol 37 (10) ◽  
pp. 1907-1914 ◽  
Author(s):  
Magda Jonášová ◽  
Ivona Matějková
Keyword(s):  
Norway Spruce ◽  
Bark Beetle ◽  
Natural Regeneration ◽  
Ips Typographus ◽  
Tree Regeneration ◽  
Vegetation Changes ◽  
Natural Disturbances ◽  
Spruce Forests ◽  
The Impact

An extensive area of Norway spruce ( Picea abies (L.) Karst.) forests in the Šumava Mountains, Central Europe, has been affected by a massive bark beetle ( Ips typographus L.) outbreak since the mid-1990s. One part of the area was left without intervention and two types of intervention have been applied in other parts: (1) the classical forest approach, based on the logging of attacked trees and (2) “sanitation”, in which attacked trees were cut down, debarked, and left lying in the stand. The main goal of our research was to test the impact of nonintervention and both types of intervention on the regeneration of the Norway spruce forests. The Norway spruce forests influenced by natural disturbances (bark beetle outbreak and windfalls) regenerated very well if left without intervention. The bark beetle outbreaks and windfalls do not represent a threat to the long-term persistence of the forests. Clearcuts resulted in formation of pioneer stages with a postponed spruce regeneration. In sanitation plots, the reduction of both previous vegetation and tree regeneration was obvious. Generally, both interventions against bark beetle delayed the recovery of Norway spruce forests.

The disturbance regime of Norway spruce forests in Bulgaria

2015 ◽  
Vol 45 (9) ◽  
pp. 1143-1153 ◽  
Author(s):  
Momchil Panayotov ◽  
Peter Bebi ◽  
Nickolay Tsvetanov ◽  
Neno Alexandrov ◽  
Lucinda Laranjeiro ◽  
...  
Keyword(s):  
Norway Spruce ◽  
Large Scale ◽  
Natural Disturbance ◽  
Disturbance Regime ◽  
Forest Reserves ◽  
Spruce Forests ◽  
The Past ◽  
Natural Range ◽  
Old Trees

Natural disturbances are among the most important factors that shape forest dynamics and forest landscapes. However, the natural disturbance regime of Norway spruce (Picea abies (L.) Karst.) forests in Europe is not well understood. We studied the disturbance regimes in three forest reserves in Bulgaria (Parangalitsa, Bistrishko branishte, and Beglika), which are representative of the range of conditions typical for P. abies ecosystems in central and southern Europe. Our data indicated that large-scale disturbances were most numerous in forests that were between 120 and 160 years old, those with unimodal diameter at breast height (DBH) distributions, and especially those located in vulnerable topographic settings. Wind disturbances ranged up to 60 ha, followed in one case by a 200 ha Ips typographus (Linnaeus, 1758) outbreak. Older forests and those with more complex structures (i.e., reverse-J DBH) were characterized by numerous small gaps but were also affected by a few larger disturbances. In some old-growth forests at highly productive sites, gaps could be so numerous that the long-term existence of old trees may become an exception. Over the past centuries, the natural range of variability of these Norway spruce forests in Bulgaria appears to have been shaped mostly by wind and bark beetle disturbances of various sizes.

Long-term development of natural regeneration in irregular, mixed stands of silver fir and Norway spruce

2018 ◽  
Vol 430 ◽  
pp. 105-116 ◽  
Author(s):  
Adrian Dănescu ◽  
Ulrich Kohnle ◽  
Jürgen Bauhus ◽  
Aaron Weiskittel ◽  
Axel T. Albrecht
Keyword(s):  
Norway Spruce ◽  
Natural Regeneration ◽  
Silver Fir ◽  
Mixed Stands

Short- and Long-Term Results of Total vs Subtotal Thyroid- ectomies in the Surgical Treatment of Graves' Disease

Swiss Surgery ◽  
2001 ◽  
Vol 7 (1) ◽  
pp. 20-24 ◽  
Author(s):  
Robert ◽  
Mariéthoz ◽  
Pache ◽  
Bertin ◽  
Caulfield ◽  
...  
Keyword(s):  
Recurrent Laryngeal Nerve ◽  
Nerve Palsy ◽  
Recurrent Laryngeal Nerve Palsy ◽  
Laryngeal Nerve ◽  
Long Term Results ◽  
Graves Disease ◽  
Laryngeal Nerve Palsy ◽  
Short And Long Term

Objective: Approximately one out of five patients with Graves' disease (GD) undergoes a thyroidectomy after a mean period of 18 months of medical treatment. This retrospective and non-randomized study from a teaching hospital compares short- and long-term results of total (TT) and subtotal thyroidectomies (ST) for this disease. Methods: From 1987 to 1997, 94 patients were operated for GD. Thirty-three patients underwent a TT (mostly since 1993) and 61 a ST (keeping 4 to 8 grams of thyroid tissue - mean 6 g). All patients had received propylthiouracil and/or neo-mercazole and were in a euthyroid state at the time of surgery; they also took potassium iodide (lugol) for ten days before surgery. Results: There were no deaths. Transient hypocalcemia (< 3 months) occurred in 32 patients (15 TT and 17 ST) and persistent hypocalcemia in 8 having had TT. Two patients developed transient recurrent laryngeal nerve palsy after ST (< 3 months). After a median follow-up period of seven years (1-15) with five patients lost to follow-up, 41 patients having had a ST are in a hypothyroid state (73%), thirteen are euthyroid (23%), and two suffered recurrent hyperthyroidism, requiring completion of thyroidectomy. All 33 patients having had TT - with follow-ups averaging two years (0.5-8) - are receiving thyroxin substitution. Conclusions: There were no instances of persistent recurrent laryngeal nerve palsy in either group, but persistent hypoparathyroidism occurred more frequently after TT. Long after ST, hypothyroidism developed in nearly three of four cases, whereas euthyroidy was maintained in only one-fourth; recurrent hyperthyroidy was rare.

Short- and long-term memory tasks predict working memory performance, and vice versa.

2019 ◽  
Vol 73 (2) ◽  
pp. 79-93 ◽  
Author(s):  
Ian Neath ◽  
Jean Saint-Aubin ◽  
Tamra J. Bireta ◽  
Andrew J. Gabel ◽  
Chelsea G. Hudson ◽  
...  
Keyword(s):  
Working Memory ◽  
Memory Performance ◽  
Long Term Memory ◽  
Term Memory ◽  
Short And Long Term
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