scholarly journals Direkte, indirekte und kombinierte Effekte von Wölfen auf die Waldverjüngung

2016 ◽  
Vol 167 (1) ◽  
pp. 3-12
Author(s):  
Andrea D. Kupferschmid ◽  
Kurt Bollmann

Direct, indirect and combined effects of wolves on tree regeneration The wolf currently returns to its traditional distribution area in central Europe. As a large carnivore, he will change the interactions between the organisms there. The impact of wolves on wild ungulates and on the vegetation cover and its composition is manifold: besides direct, numeric effects of wolves on the abundance and demography of their prey populations (like chamois, roe deer and red deer), indirect functional effects through mediated behavior of ungulates are also reported. In a first phase of wolf recolonization with low population density in a region, the functional effects as changes in the spatio-temporal use of habitats and resources are considered to be dominant because the wild ungulates attempt avoiding to become a prey. Later, in phases with higher wolf densities, direct numeric effects on the abundance of prey species should become more obvious. Such interactions among predator and prey species also have an impact on the browsing of tree regeneration. Since the spatio-temporal habitat use of prey species is mediated by the occurrence and abundance of large predators, we cannot assume that the browsing level will gradually decrease in general. Wild ungulates could more often hide or retreat into steep and rocky terrain or towards human settlement. Hence, trophic interactions between predators, herbivores and forests are complex and multilayered, in particular because forest ecosystems in central Europe are strongly influenced by forestry and hunting practices. This limits the trophic cascading impact of carnivores on forest. Our review demonstrates that the equation “wolf = less ungulates = fewer browsing” is not a general rule.

2019 ◽  
Vol 170 (3) ◽  
pp. 125-134
Author(s):  
Andrea D. Kupferschmid ◽  
Peter Brang ◽  
Harald Bugmann

Assessment of the impact of ungulate browsing on tree regeneration Browsing percentage is an objective and reproducible measure of the frequency of browsing by wild ungulates on tree regeneration. However, this relative number of browsed terminal shoots accounts for little of the effective long-term influence of browsing on tree regeneration. Apart from browsing percentage, the following four factors are important for estimating the influence of browsing: the density of tree regeneration, the within-tree browsing intensity, the height growth of the tree regeneration (and thus the time needed to grow out of the reach of browsers and the browsing-induced loss of height increment), and the mortality induced by browsing. At least the first three of these factors can be obtained easily and should thus be included in future browsing inventories.


2019 ◽  
Vol 170 (3) ◽  
pp. 135-141
Author(s):  
Michiel Fehr ◽  
Nora Zürcher Gasser ◽  
Olivier Schneider ◽  
Thomas Burger ◽  
Andrea D. Kupferschmid

Expert assessments of the ungulate influence on tree regeneration (essay) Roe deer, red deer and chamois browse on shoots of tree saplings or fray and peel their bark. This ungulate influence can be so strong that it changes the composition of the tree species mixture and the number of stems. Repeated expert assessments of tree saplings allow a comprehensive statement about the strength and development of this ungulate influence and provide a basis for discussions about possible actions to be taken. However, this only applies if the expert assessment describes the influence of ungulates objectively, transparently and neutrally. In the text, the authors – members of the working group Forest and Wildlife of the Swiss Forestry Society – propose a concrete procedure for the expert assessment. The core of which is the assessment of the impact of ungulates in four classes. The use of these ungulate influence classes makes it possible to evaluate objectively the vertical growth of main and admixed tree species as well as the vertical growth of ungulate-sensitive and non-sensitive tree species. These classes enable a calculation of the proportion of forest area where browsing does prevent silvicultural objectives from being met with respect to i) the composition of ungulate-sensitive main and admixed tree species and ii) the number of stems (target values for regeneration). A harmonization of ungulate influence classes facilitates the assessment of canton-wide wildlife management units and gener ally simplifies the dialogue between cantons.


Forests ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 764 ◽  
Author(s):  
Andrea Doris Kupferschmid ◽  
Lukas Bütikofer ◽  
Torsten Hothorn ◽  
Andreas Schwyzer ◽  
Peter Brang

Ungulate browsing is a major factor influencing tree regeneration. However, it is unclear if the observed increase in ungulate abundance in Central Europe implies increased browsing, and which other factors influence the incidence of browsing. We investigated the impact of forty variables (site, climate, forest and ungulates) on the probability of leader shoot browsing of six tree species which are frequent in Switzerland. The analysis was based on a large dataset including 49 monitoring areas, each containing 25–64 circular plots, in which 10 to 130 cm tall seedlings were repeatedly assessed. Browsing probability was estimated for each plot and year by mixed effects logistic regression and used as a response in random forests to disentangle the influence of the explanatory variables. Browsing probability was positively correlated with ungulate density measures (number culled by hunting or found dead) for all six tree species. Where beyond roe deer, some red deer and/or chamois were present, the browsing probability was higher. Small timber tree stands had less browsing than young growth and thicket stands. Seedlings tended to be more frequently browsed in stands with >80% canopy shading. Browsing increased with increasing understory cover, independent of vegetation category. In conclusion, browsing is a multifactorial phenomenon and ungulate density estimates alone do not explain the whole browsing probability.


2015 ◽  
Vol 166 (6) ◽  
pp. 420-431 ◽  
Author(s):  
Andrea D. Kupferschmid ◽  
Caroline Heiri ◽  
Markus Huber ◽  
Michiel Fehr ◽  
Maurus Frei ◽  
...  

Influence of wild ungulates on forest regeneration: overview for Switzerland Terminal shoots of tree saplings are part of the diet of chamois, roe and red deer, which in turn can affect forest regeneration. We investigated the current extent of browsing influence on the Swiss forest and the existence of regional differences. Our overview includes all available, regionally assessed data on the influence of roe deer, chamois and red deer in Switzerland, i.e. data of the fourth Swiss National Forest Inventory (NFI 2009/13) and data from the cantons derived from 1) representative sample plot inventories, 2) surveys in selected forest areas and 3) assessments by expert opinion. In the time period between approx. 2009 and 2014 no larger region of Switzerland stood out with respect to browsing influence. On the level of the ungulates home range or forest districts we found large differences in the browsing impact, but on at least two-thirds of the assessed forest area of Switzerland browsing had no major influence on single tree species nor on forest regeneration in general (browsing level 1). In the colline vegetation belt frequent browsing has the most adverse influence on oak, in the montane belt on silver fir and in the lower subalpine belt on maple and rowan. Investigations focusing on a better understanding of the relationship between the objectively measurable browsing intensity and regeneration density as well as data on seedlings <10 cm would allow an even better assessment of the browsing influence on the forest. With Swiss-wide standardized assessments by expert opinion within uniformly defined ungulate home ranges, the comparability of data on the impact of wild ungulates on the Swiss forest could be further improved.


2017 ◽  
Vol 7 (4) ◽  
pp. 65-72
Author(s):  
V. N. Shmagol' ◽  
V. L. Yarysh ◽  
S. P. Ivanov ◽  
V. I. Maltsev

<p>The long-term population dynamics of the red deer (<em>Cervus elaphus</em> L.) and European roe deer (<em>Capreolus</em> <em>capreolus</em> L.) at the mountain and forest zone of Crimea during 1980-2017 is presented. Fluctuations in numbers of both species are cyclical and partly synchronous. Period of oscillations in the population of red deer is about 25 years, the average duration of the oscillation period of number of roe deer is 12.3 years. During the fluctuations in the number the increasing and fall in population number of the red deer had been as 26-47 %, and roe deer – as 22-34 %. Basing on the dada obtained we have assumed that together with large-scale cycles of fluctuations in population number of both red deer and roe deer the short cycles of fluctuations in the number of these species with period from 3.5 to 7.5 years take place. Significant differences of the parameters of cyclical fluctuations in the number of roe deer at some sites of the Mountainous Crimea: breaches of synchronicity, as well as significant differences in the duration of cycles are revealed. The greatest deviations from the average values of parameters of long-term dynamics of the number of roe deer in Crimea are noted for groups of this species at two protected areas. At the Crimean Nature Reserve the cycle time of fluctuations of the numbers of roe deer was 18 years. At the Karadag Nature Reserve since 1976 we can see an exponential growth in number of roe deer that is continued up to the present time. By 2016 the number of roe deer reached 750 individuals at a density of 437 animals per 1 thousand ha. Peculiarity of dynamics of number of roe deer at some sites proves the existence in the mountain forest of Crimea several relatively isolated groups of deer. We assumed that "island" location of the Crimean populations of red deer and European roe deer, their relatively little number and influence of permanent extreme factors of both natural and anthropogenic origination have contributed to a mechanism of survival of these populations. The elements of such a mechanism include the following features of long-term dynamics of the population: the reduction in the period of cyclic population fluctuations, while maintaining their amplitude and the appearance of additional small cycles, providing more flexible response of the population to the impact of both negative and positive environmental factors. From the totality of the weather conditions for the Crimean population of roe deer the recurring periods of increases and downs in the annual precipitation amount may have relevance. There was a trend of increase in the roe deer population during periods of increasing annual precipitation.</p>


Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1395
Author(s):  
Alberto Espí ◽  
Ana del Cerro ◽  
Álvaro Oleaga ◽  
Mercedes Rodríguez-Pérez ◽  
Ceferino M. López ◽  
...  

This study aimed to investigate the seroprevalence of C. burnetii in domestic ruminants, wild ungulates, as well as the current situation of Q fever in humans in a small region in northwestern Spain where a close contact at the wildlife–livestock–human interface exists, and information on C. burnetii infection is scarce. Seroprevalence of C. burnetii was 8.4% in sheep, 18.4% in cattle, and 24.4% in goats. Real-time PCR analysis of environmental samples collected in 25 livestock farms detected Coxiella DNA in dust and/or aerosols collected in 20 of them. Analysis of sera from 327 wild ungulates revealed lower seroprevalence than that found in domestic ruminants, with 8.4% of Iberian red deer, 7.3% chamois, 6.9% fallow deer, 5.5% European wild boar and 3.5% of roe deer harboring antibodies to C. burnetii. Exposure to the pathogen in humans was determined by IFAT analysis of 1312 blood samples collected from patients admitted at healthcare centers with Q fever compatible symptoms, such as fever and/or pneumonia. Results showed that 15.9% of the patients had IFAT titers ≥ 1/128 suggestive of probable acute infection. This study is an example of a One Health approach with medical and veterinary institutions involved in investigating zoonotic diseases.


Water ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 307
Author(s):  
Chi Zhang ◽  
Naixia Mou ◽  
Jiqiang Niu ◽  
Lingxian Zhang ◽  
Feng Liu

Changes in snow cover over the Tibetan Plateau (TP) have a significant impact on agriculture, hydrology, and ecological environment of surrounding areas. This study investigates the spatio-temporal pattern of snow depth (SD) and snow cover days (SCD), as well as the impact of temperature and precipitation on snow cover over TP from 1979 to 2018 by using the ERA5 reanalysis dataset, and uses the Mann–Kendall test for significance. The results indicate that (1) the average annual SD and SCD in the southern and western edge areas of TP are relatively high, reaching 10 cm and 120 d or more, respectively. (2) In the past 40 years, SD (s = 0.04 cm decade−1, p = 0.81) and SCD (s = −2.3 d decade−1, p = 0.10) over TP did not change significantly. (3) The positive feedback effect of precipitation is the main factor affecting SD, while the negative feedback effect of temperature is the main factor affecting SCD. This study improves the understanding of snow cover change and is conducive to the further study of climate change on TP.


2021 ◽  
Vol 37 ◽  
pp. 205-215
Author(s):  
Heng Chen ◽  
Hongmei Cheng ◽  
Aibin Xu ◽  
Yi Xue ◽  
Weihong Peng

ABSTRACT The fracture field of coal and rock mass is the main channel for gas migration and accumulation. Exploring the evolution law of fracture field of coal and rock mass under the condition of drilling and slitting construction has important theoretical significance for guiding efficient gas drainage. The generation and evolution process of coal and rock fissures is also the development and accumulation process of its damage. Therefore, based on damage mechanics and finite element theory, the mathematical model is established. The damage variable of coal mass is defined by effective strain, the elastoplastic damage constitutive equation is established and the secondary development of finite element program is completed by FORTRAN language. Using this program, the numerical simulation of drilling and slitting construction of the 15-14120 mining face of Pingdingshan No. 8 Mine is carried out, and the effects of different single borehole diameters, different kerf widths and different kerf heights on the distribution area of surrounding coal fracture field and the degree of damage are studied quantitatively. These provide a theoretical basis for the reasonable determination of the slitting and drilling arrangement parameters at the engineering site.


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