Ungulate Species and Abundance as well as Environmental Factors Determine the Probability of Terminal Shoot Browsing on Temperate Forest Trees

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.

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Gutachtliche Beurteilung des Wildeinflusses auf die Waldverjüngung (Essay)

Schweizerische Zeitschrift fur Forstwesen ◽

10.3188/szf.2019.0135 ◽

2019 ◽

Vol 170 (3) ◽

pp. 135-141

Author(s):

Michiel Fehr ◽

Nora Zürcher Gasser ◽

Olivier Schneider ◽

Thomas Burger ◽

Andrea D. Kupferschmid

Keyword(s):

Tree Species ◽

Roe Deer ◽

Tree Regeneration ◽

Expert Assessment ◽

Vertical Growth ◽

Forestry Society ◽

Target Values ◽

Expert Assessments ◽

Number Of Stems ◽

The Impact

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.

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Long-term effects of stump removal and tree species composition on the diversity and structure of soil fungal communities

FEMS Microbiology Ecology ◽

10.1093/femsec/fiaa061 ◽

2020 ◽

Vol 96 (5) ◽

Author(s):

Dixi Modi ◽

Suzanne Simard ◽

Jean Bérubé ◽

Les Lavkulich ◽

Richard Hamelin ◽

...

Keyword(s):

Species Composition ◽

Fungal Community ◽

Tree Species ◽

Management Practice ◽

Tree Regeneration ◽

Root Disease ◽

Fungal Communities ◽

Tree Species Composition ◽

The Impact

ABSTRACT Stump removal is a common forest management practice used to reduce the mortality of trees affected by the fungal pathogen-mediated root disease, Armillaria root rot, but the impact of stumping on soil fungal community structure is not well understood. This study analyzed the long-term impact of stumping and tree species composition on the abundance, diversity and taxonomic composition of soil fungal communities using internal transcribed spacer (ITS) marker-based DNA metabarcoding in a 48-year-old trial at Skimikin, British Columbia. A total of 108 samples were collected from FH (fermented and humus layers), and soil mineral horizons (A and B) from stumped and unstumped plots of six tree species treatments (pure stands and admixtures of Douglas-fir, western red-cedar and paper birch). Fungal α-diversity in the A horizon significantly increased with stumping regardless of tree species composition, while β-diversity was significantly affected by stumping in all the horizons. We also observed that the relative abundance of the saprotrophic fungal community declined while that of the ectomycorrhizal fungal community increased with stumping. In conclusion, increase in ectomycorrhizal fungal associations, which are positively associated with tree productivity, suggests that stumping can be considered a good management practice for mitigating root disease and promoting tree regeneration.

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Direkte, indirekte und kombinierte Effekte von Wölfen auf die Waldverjüngung

Schweizerische Zeitschrift fur Forstwesen ◽

10.3188/szf.2016.0003 ◽

2016 ◽

Vol 167 (1) ◽

pp. 3-12

Author(s):

Andrea D. Kupferschmid ◽

Kurt Bollmann

Keyword(s):

Central Europe ◽

Prey Species ◽

Roe Deer ◽

General Rule ◽

Tree Regeneration ◽

Distribution Area ◽

Wild Ungulates ◽

Spatio Temporal ◽

Large Predators ◽

The Impact

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.

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ANALYSIS OF THE UNDERGROWTH PLANTINGS OF TEREBINTH (PISTACIA MUTICA) IN THE KARADAG NATURE RESERVE

Scientific Notes of V.I. Vernadsky Crimean Federal University. Biology. Chemistry ◽

10.37279/2413-1725-2020-6-2-291-303 ◽

2020 ◽

Vol 6(72) (2) ◽

pp. 291-303

Author(s):

V. L. Yarysh ◽

G. E. Yarysh

Keyword(s):

Tree Species ◽

Roe Deer ◽

Capreolus Capreolus ◽

Relict Species ◽

Quercus Pubescens ◽

Damage Monitoring ◽

Green Book ◽

Extent Of Damage ◽

Young Growth ◽

Ongoing Monitoring

This article discusses the state and the resumption of tree species in plantations of terebinth (Pistacia mutica) on land of the Karadag reserve. Pistacia mutica is a Mediterranean relict species of the Tertiary period, included in the Red Books of Russia, Crimea and Ukraine. Terebinth (Pistacia mutica) creates rare relict plant communities (formation P. mutica) listed in the Green Book of Ukraine. A comparative analysis of small, medium and large undergrowth in the sample areas laid in 2005–2006 and in 2017 for undergrowth damage monitoring. Counting of the number and extent of damage to young growth stands of sessile in 2005–2006 and in 2017 – have shown that the undergrowth density was 2.0 thousand units/ha and 3.5 thousand units/ha correspondently. The degree of damaged undergrowth in 2005–2006 and in 2017 was 5.0 % and 88.6 %, respectively. The number of undergrowth in plantations in 2005–2006 is 1.7 times lower than the number of undergrowth in 2017. At the same time, the density of large undergrowth in plantations in 2005–2006 is 3 times higher than the density of large undergrowth in stands in 2017. The studies noted that there is replacement of the main forest-forming specie of terebinth (Pistacia mutica) bedrock prevailing in the plantations, in the downy oak (Quercus pubescens) and oleaster pear (Pyrus eleagnifolia). In undergrowth Pistacia mutica takes 29 %, and in large undergrowth it takes about 12 %. Most of damaged species is downy oak in all categories of undergrowth and oleaster pear in young growth stands. The undergrowth of European ash (Fraxinus excelsior) is rare. As the number of European roe deer (Capreolus capreolus Linnaeus, 1758) grows, the pressure on the floristic complexes of the reserve increases too, due to excessive population density of this species (the her density in 2016 is 10 time higher than optimal density – 437 species on 1000 ha ). A great destruction of the undergrowth observed. Most of damaged wildlife species is downy oak in all categories of undergrowth, and oleaster pear in small undergrowth. Meanwhile, the share of affected undergrowth of terebinth increased from 2,9 to 85.0 %, the share of downy oak – from 4.8 to 93.4 %, and the share oleaster pear – from 3,3 to 96,4 %. Renewal of tree species in plantations of Pistacia mutica in the Karadag reserve should be considered unsatisfactory. P. mutica populations in Kardag reserve require ongoing monitoring and conservation.

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Long-term population dynamics of the red deer and European roe deer at the protected and not-protected areas in Mountain Crimea

Ukrainian Journal of Ecology ◽

10.15421/2017_88 ◽

2017 ◽

Vol 7 (4) ◽

pp. 65-72

Author(s):

V. N. Shmagol' ◽

V. L. Yarysh ◽

S. P. Ivanov ◽

V. I. Maltsev

Keyword(s):

Population Dynamics ◽

Protected Areas ◽

Red Deer ◽

Nature Reserve ◽

Roe Deer ◽

Precipitation Amount ◽

Annual Precipitation ◽

Population Number ◽

The Impact

The long-term population dynamics of the red deer (Cervus elaphus L.) and European roe deer (Capreolus capreolus 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.

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Effect of Competition and Climatic Conditions on the Growth of Beech in the Mixed Pine Beech Stand: Lithuanian Case Study

Environmental Sciences Proceedings ◽

10.3390/iecf2020-07961 ◽

2020 ◽

Vol 3 (1) ◽

pp. 49

Author(s):

Edgaras Linkevičius ◽

Gerda Junevičiūtė

Keyword(s):

Intraspecific Competition ◽

Tree Species ◽

Forest Growth ◽

Competition Effect ◽

Diameter Increment ◽

Cart Analysis ◽

Crown Width ◽

Beech Stand ◽

Negative Effect ◽

The Impact

Climate change and warming will potentially have profound effects on forest growth and yield, especially for pure stands in the near future. Thus, increased attention has been paid to mixed stands, e.g., pine and beech mixtures. However, the interaction of tree species growing in mixtures still remains unknown. Thus, the aim of this study was to investigate the impact of the interspecific and intraspecific competition to diameter, height, and crown width of pine and beech trees growing in mixtures, as well as to evaluate the impact of climatic indicators to the beech radial diameter increment. The data was collected in 2017 at the mixed mature pine beech double layer stand, located in the western part of Lithuania. The sample plot of 1.2 hectare was established and tree species, diameter at the breast height, tree height, height-to-crown base, height-to-crown width, and position were measured for all 836 trees. Additionally, a representative sample of radial diameter increments were estimated only for the beech trees by taking out core discs at the height of 1 m when the stand was partially cut. Competition analysis was based on the distance-dependent competition index, which was further based on crown parameters. Climatic effect was evaluated using classification and regression tree (CART) analysis. We found almost no interspecific competition effect to diameter, height, or crown width for both tree species growing in the first layer. However, it had an effect on beeches growing in the second layer. The intraspecific competition effect was important for pine and beech trees, showing a negative effect for both of them. Our results show the possible coexistence of these tree species due to niche differentiation. An analysis of climatic indicators from 1991–2005 revealed that precipitation from February–May of the current vegetation year and mean temperatures from July to September expressed radial diameter increment effects for beech trees. Low temperatures during March and April, as well as high precipitation during January, had a negative effect on beech radial increments. From 2006–2016, the highest effect on radial diameter increments was the mean temperatures from July to September, as well as the precipitation in January of the current year. From 1991–2016, the highest effect on radial diameter increments was the temperature from July to September 1991–2016 and the precipitation in June 1991–2016. Generally, cool temperatures and higher precipitation in June had a positive effect on beech radial increments. Therefore, our results show a sensitivity to high temperatures and droughts during summer amid Lithuanian’s growth conditions.

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The Innovation of Government Bonds in the Growth of an Emergent Capital Market

Journal of Open Innovation Technology Market and Complexity ◽

10.3390/joitmc7010103 ◽

2021 ◽

Vol 7 (1) ◽

pp. 103

Author(s):

Cordelia Onyinyechi Omodero ◽

Philip Olasupo Alege

Keyword(s):

Capital Market ◽

Research Work ◽

Government Bonds ◽

Market Capitalization ◽

Market Growth ◽

Explanatory Variables ◽

The Government ◽

The Impact ◽

Total Market ◽

The Capital Market

The growth of an emerging capital market is necessary and requires all available resources and inputs from various sources to realize this objective. Several debates on government bonds’ contribution to Nigeria’s capital market developmental growth have ensued but have not triggered comprehensive studies in this area. The present research work seeks to close the breach by probing the impact of government bonds on developing the capital market in Nigeria from 2003–2019. We employ total market capitalization as the response variable to proxy the capital market, while various government bonds serve as the independent variables. The inflation rate moderates the predictor components. The research uses multiple regression technique to assess the explanatory variables’ impact on the total market capitalization. At the same time, diagnostic tests help guarantee the normality of the regression model’s data distribution and appropriateness. The findings reveal that the Federal Government of Nigeria’s (FGN) bond is statistically significant and positive in influencing Nigeria’s capital market growth. The other predictor variables are not found significant in this study. The study suggests that the Government should improve on the government bonds’ coupon, while still upholding the none default norm in paying interest and refunding principal to investors when due.

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Beavers, Bugs and Chemistry: A Mammalian Herbivore Changes Chemistry Composition and Arthropod Communities in Foundation Tree Species

Forests ◽

10.3390/f12070877 ◽

2021 ◽

Vol 12 (7) ◽

pp. 877

Author(s):

Rachel M. Durben ◽

Faith M. Walker ◽

Liza Holeski ◽

Arthur R. Keith ◽

Zsuzsi Kovacs ◽

...

Keyword(s):

Tree Species ◽

Castor Canadensis ◽

Habitat Type ◽

Food Preferences ◽

Woody Species ◽

Juvenile Growth ◽

Arthropod Community ◽

Riparian Ecosystems ◽

Arthropod Communities ◽

The Impact

The North American beaver (Castor canadensis Kuhl) and cottonwoods (Populus spp.) are foundation species, the interactions of which define a much larger community and affect a threatened riparian habitat type. Few studies have tested the effect of these interactions on plant chemistry and a diverse arthropod community. We experimentally examined the impact of beaver foraging on riparian communities by first investigating beaver food preferences for one cottonwood species, Fremont cottonwood (P. fremontii S. Watson), compared to other locally available woody species. We next examined the impact of beaver foraging on twig chemistry and arthropod communities in paired samples of felled and unfelled cottonwood species in northern Arizona (P. fremontii) and southwestern Colorado (narrowleaf cottonwood, P. angustifolia James, and Eastern cottonwood, P. deltoides W. Bartram ex Marshall). Four major patterns emerged: (1) In a cafeteria experiment, beavers chose P. fremontii six times more often than other woody native and exotic species. (2) With two cottonwood species, we found that the nitrogen and salicortin concentrations were up to 45% greater and lignin concentration 14% lower in the juvenile resprout growth of felled trees than the juvenile growth on unfelled trees (six of seven analyses were significant for P. fremontii and four of six were significant for P. angustifolia). (3) With two cottonwood species, arthropod community composition on juvenile branches differed significantly between felled and unfelled trees, with up to 38% greater species richness, 114% greater relative abundance and 1282% greater species diversity on felled trees (six of seven analyses with P. fremontii and four of six analyses with P. angustifolia were significant). The above findings indicate that the highest arthropod diversity is achieved in the heterogenous stands of mixed felled and unfelled trees than in stands of cottonwoods, where beavers are not present. These results also indicate that beaver herbivory changes the chemical composition in 10 out of 13 chemical traits in the juvenile growth of two of the three cottonwood species to potentially allow better defense against future beaver herbivory. (4) With P. deltoides, only one of five analyses in chemistry was significant, and none of the four arthropod community analyses were significant, suggesting that this species and its arthropod community responds differently to beaver. Potential reasons for these differences are unknown. Overall, our findings suggest that in addition to their impact on riparian vegetation, other mammals, birds, and aquatic organisms, beavers also may define the arthropod communities of two of three foundation tree species in these riparian ecosystems.

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To Swab or Not to Swab? The Lesson Learned in Italy in the Early Stage of the COVID-19 Pandemic

Applied Sciences ◽

10.3390/app11094042 ◽

2021 ◽

Vol 11 (9) ◽

pp. 4042

Author(s):

Paola Berchialla ◽

Maria Teresa Giraudo ◽

Carmen Fava ◽

Andrea Ricotti ◽

Giuseppe Saglio ◽

...

Keyword(s):

Early Phase ◽

Early Stage ◽

Respiratory Illness ◽

Explanatory Variables ◽

Daily Number ◽

Testing Strategies ◽

Serious Infections ◽

The Impact ◽

Epidemiological Link ◽

Severe Respiratory Illness

Testing for the SARS-CoV-2 infection is critical for tracking the spread of the virus and controlling the transmission dynamics. In the early phase of the pandemic in Italy, the decentralized healthcare system allowed regions to adopt different testing strategies. The objective of this paper is to assess the impact of the extensive testing of symptomatic individuals and their contacts on the number of hospitalizations against a more stringent testing strategy limited to suspected cases with severe respiratory illness and an epidemiological link to a COVID-19 case. A Poisson regression modelling approach was adopted. In the first model developed, the cumulative daily number of positive cases and a temporal trend were considered as explanatory variables. In the second, the cumulative daily number of swabs was further added. The explanatory variable, given by the number of swabs over time, explained most of the observed differences in the number of hospitalizations between the two strategies. The percentage of the expected error dropped from 70% of the first, simpler model to 15%. Increasing testing to detect and isolate infected individuals in the early phase of an outbreak improves the capability to reduce the spread of serious infections, lessening the burden of hospitals.

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How far from the road should land cover be assessed? A case study on mesopredator mortality on roads

European Journal of Wildlife Research ◽

10.1007/s10344-021-01461-x ◽

2021 ◽

Vol 67 (2) ◽

Author(s):

Angelika Nieszała ◽

Daniel Klich

Keyword(s):

Land Cover ◽

Red Fox ◽

Home Range Size ◽

Buffer Size ◽

Local Conditions ◽

Explanatory Variables ◽

The Road ◽

Spatially Correlated ◽

European Badger ◽

The Impact

AbstractThe methods used to assess the significance of land cover in the vicinity of a road for the mortality of mesopredators are diverse. In assessing the effect of land cover along the road on road causalities, scientists use various buffer sizes, or even no buffer along the road. The aim of this study was to verify how results of land cover effects on the mortality of mesopredators on roads may differ when analyzing various buffer sizes from the road. We assessed road causalities in the Warmian-Masurian voivodeship (Poland) from 3 consecutive years: 2015, 2016, and 2017. The roads were divided into equal sections of 2000 m each with buffer size of radius: 10, 250, 500, and 1000 m. We analyzed the number of road kills of red fox and European badger separately in a generalized linear model, whereas explanatory variables we used land cover types (based on the Corine Land Cover inventory) and traffic volume. Mean annual mortality from road collisions amounts to 2.36% of the red fox population and 3.82% of the European badger population. We found that the buffer size determines the results of the impact of land cover on mesocarnivore mortality on roads. The red fox differed from the European badger in response to land cover depending on the buffer size. The differences we have shown relate in particular to built-up areas. Our results indicate a 500-m buffer as best reflecting the land cover effects in road kills of both species. This was confirmed by model evaluation and a tendency to use or avoid the vicinity of human settlements of the analyzed species. We concluded that buffer size will probably affect mostly the significance of cover types that are spatially correlated with roads, positively or negatively. We suggest that the home range size of given species in local conditions should be assessed before determining the size of the buffer for analysis.

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