scholarly journals Effects of Twenty Years of Ungulate Browsing on Forest Regeneration at Paneveggio Reserve, Italy

Forests ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 612
Author(s):  
Davide D’Aprile ◽  
Giorgio Vacchiano ◽  
Fabio Meloni ◽  
Matteo Garbarino ◽  
Renzo Motta ◽  
...  
Keyword(s):  
Forest Regeneration ◽  
Monitoring Program ◽  
Environmental Drivers ◽  
Large Herbivores ◽  
Cascading Effects ◽  
Specific Composition ◽  
Seed Dispersion ◽  
Nature Park ◽  
Conservation Plans ◽  
Mature Stands

Forest ecosystems are threatened by different natural disturbances. Among them, the irruption of large herbivores represents one of the most alarming issues. Several local-scale studies have been carried out to clarify the mechanisms governing ungulate–forest interactions, to understand the effect of wild ungulates overabundance, and to apply conservation plans. However, information at large scales, over long periods of observation and from unmanipulated conditions is still scarce. This study aims to improve our knowledge in this field by using repeated inventories to investigate: the types of damage produced by ungulate populations on young trees, the drivers that stimulate browsing activity and its consequences on the specific composition of seedlings and saplings. To reach these goals, we used data collected during a twenty-year monitoring program (1994–2014) in the forests of Paneveggio-Pale di San Martino Nature Park (Italy). We applied descriptive statistics to summarize the data, GLMs to identify the drivers of browsing activity and Non-Metric Multidimensional Scaling (nMDS) ordinations to investigate the changes in specific composition of young trees across 20 years. We detected increasing browsing activity from 1994 to 2008 and a decline in 2014. Ungulates browsed preferentially in mature stands, and fed mostly on seedlings and saplings under 150 cm of height. The analysis of the environmental drivers of browsing pressure on the smallest size classes of plants suggests that foraging behavior is influenced by snowpack conditions, ungulate density and seasonality. Moreover, results underline the fact that ungulates feed mostly on palatable species, especially European rowan, but can also use unpalatable plants as emergency food under high competition levels. nMDS results suggest that rowan seed dispersion might be promoted by deer movements, however, saplings of this species were not able to exceed 30 cm of height because of heavy browsing. This bottleneck effect led to the dominance of unpalatable species, mostly Norway spruce, reducing diversity during forest regeneration. If prolonged, this effect could lead to a reduction of tree species richness, with cascading effects on many parts of the ecosystem, and threatening the resilience of the forest to future disturbances.

Dendrometer measurements of arctic-alpine dwarf shrubs and micro-environmental drivers of plant growth - Dataset from long-term alpine ecosystem research in central Norway

Erdkunde ◽  
2021 ◽  
Author(s):  
Jörg Löffler ◽  
Svenja Dobbert ◽  
Roland Pape ◽  
Dirk Wundram
Keyword(s):  
Root Zone ◽  
Monitoring Program ◽  
Growth Patterns ◽  
Environmental Data ◽  
Environmental Drivers ◽  
Horizontal Distance ◽  
Ecosystem Research ◽  
Alpine Ecosystem ◽  
Vegetation Shifts

Here, we present fine-scale measurements of stem diameter variation from three common arctic-alpine dwarf-shrub species monitored in two mountain regions of Central Norway. All three species (Betula nana, Empetrum nigrum ssp. hermaphroditum, and Phyllodoce caerulea) are abundant within the studied regions and highly important contributors to potential future arctic-alpine vegetation shifts. A profound understanding of their radial growth patterns therefore has the potential to yield crucial information regarding climate-growth relations within these ecosystems. We used high-resolution dendrometers (type DRO) to monitor 120 specimens, taking measurements near the shoot base of one major horizontal stem. Along with the shrub growth measurements, we measured on-site micro-environmental data at each studied site, including shoot zone and root zone temperatures as well as soil moisture. All data were recorded at an hourly scale and are presented as daily mean values. The monitoring period spanned five full years (2015 - 2019), with additional data from 2014 and 2020. Data were collected within one of the most continental climate regions of Europe, the Vågå/Innlandet region, and in the oceanic climate region Geiranger/Møre og Romsdal, spanning a steep climate gradient over just ~100 km horizontal distance. Both study regions are characterized by steep elevational gradients and highly heterogeneous micro-topography. The studied sites were chosen to represent these natural conditions using the transect principle. The collection of our original data is subject of our long-term alpine ecosystem monitoring program since 1991, from which numerous publications function as the basis for a recent project on the use of dendrometer data in alpine ecosystem studies.

scholarly journals Cascading effects of a highly specialized beech-aphid-fungus interaction on forest regeneration

2014 ◽  
Author(s):  
Susan Susan Cook-Patton ◽  
Lauren Maynard ◽  
Nathan Susan Lemoine ◽  
Jessica Susan Shue ◽  
John D Parker
Keyword(s):  
Forest Regeneration ◽  
Host Density ◽  
Common Garden ◽  
Fagus Grandifolia ◽  
Common Garden Experiment ◽  
American Beech ◽  
Cascading Effects ◽  
Specialist Herbivores ◽  
Negative Impacts ◽  
Survival Of Seedlings

Specialist herbivores are often thought to benefit the larger plant community, because they prevent their host species from becoming competitively dominant. In contrast, specialist enemies are not generally expected to have negative impacts on non-hosts. However, we describe a cascade of indirect interactions whereby a specialist sooty mold (Scorias spongiosa) colonizes the honeydew from a specialist beech aphid (Grylloprociphilus imbricator), ultimately decreasing the survival of seedlings beneath American beech trees (Fagus grandifolia). A common garden experiment indicated that this mortality resulted from moldy honeydew impairing leaf function rather than from chemical or microbial changes to the soil. In addition, aphids consistently colonized the same beech trees regardless of host density, suggesting that seedling-depauperate islands may form beneath these trees. Thus this highly specialized three-way beech-aphid-fungus interaction has the potential to impact local forest regeneration via a cascade of indirect effects.

scholarly journals Climate and environmental drivers of berry productivity from the forest–tundra ecotone to the high Arctic in Canada

2020 ◽  
Vol 6 (4) ◽  
pp. 529-544
Author(s):  
Noémie Boulanger-Lapointe ◽  
Greg H.R. Henry ◽  
Esther Lévesque ◽  
Alain Cuerrier ◽  
Sarah Desrosiers ◽  
...  
Keyword(s):  
Monitoring Program ◽  
Growing Season ◽  
High Arctic ◽  
Environmental Drivers ◽  
Climate Variables ◽  
Vaccinium Uliginosum ◽  
Forest Tundra ◽  
Environmental Controls ◽  
Circumpolar North ◽  
Northern Edge

Berry shrubs are found across the circumpolar North where they are an important source of food for people and animals. However, the environmental controls on berry productivity in these regions is poorly understood. This study presents the results of an ongoing berry productivity monitoring program for Empetrum nigrum L., Vaccinium uliginosum L., and Vaccinium vitis-idaea L. from the forest–tundra ecotone to the high Arctic in Canada. Berry productivity was the highest recorded for these species with up to 119 berries/m2 (E. nigrum) and 661 berries/m2 (V. uliginosum) measured at one plot in Pangnirtung. On average, berry productivity for E. nigrum and V. uliginosum was higher toward the northern edge of the species distribution range. The climate variables important for the productivity of V. uliginosum in high Arctic sites were closely associated with the onset of the growing season and water availability during the growing season, whereas those important in the low Arctic sites reflected conditions during the growing season. None of the climate variables used were associated with the productivity of E. nigrum and V. vitis-idaea, likely due to complex responses and length of the time-series, thus highlighting the importance of continued monitoring in partnership with northern people and institutions.

Spatiotemporal dynamics of natural tree regeneration in unmanaged subalpine conifer forests with high wild ungulate densities

2015 ◽  
Vol 45 (6) ◽  
pp. 607-614 ◽  
Author(s):  
Martin Brüllhardt ◽  
Anita C. Risch ◽  
Flurin Filli ◽  
Rudolf M. Haller ◽  
Martin Schütz
Keyword(s):  
Forest Regeneration ◽  
Tree Regeneration ◽  
Systematic Sampling ◽  
Conifer Forests ◽  
Large Herbivores ◽  
Wild Ungulate ◽  
Positive Effects ◽  
Apical Shoot ◽  
Swiss National Park ◽  
Long Term Impact

Increasing wild ungulate populations in the northern hemisphere led to extensive research on their influence on forest regeneration. According to the results of different studies, high ungulate densities may alter forest structure and composition, as well as inhibit forest regeneration. However, little is known about the long-term impact of large herbivores on forest dynamics at the landscape scale. Therefore, we studied forest regeneration in conifer forests of the highly protected Swiss National Park. We assessed sapling densities and apical shoot loss by repeated systematic sampling in 2003 and in 2011–2012 in two valleys featuring exceptionally high densities of wild ungulates of up to 86 individuals per vegetation-covered square kilometre during summer and 28 individuals per vegetation-covered square kilometre during winter. Mean apical shoot loss ranged between 2.9% and 10.6% depending on study site and assessment year. In addition to the increasing sapling densities, these results suggest that ungulates had little impact on tree establishment in the studied subalpine conifer forests. Additionally, sapling diversity was higher on plots repeatedly influenced by ungulates (apical shoot loss), suggesting rather positive effects of ungulates on sapling diversity. Habitat containing a mixture of forest and grassland without livestock or human disturbance provides a high-quality environment for ungulates, which likely explains the low impact of ungulates on forest regeneration in our study area.

scholarly journals Regulation of trophic architecture across spatial scales in a major river network

2018 ◽  
Author(s):  
Eric Harvey ◽  
Florian Altermatt
Keyword(s):  
Trophic Structure ◽  
Spatial Scales ◽  
Monitoring Program ◽  
Trophic Group ◽  
Ecosystem Functions ◽  
Rhine River ◽  
Cascading Effects ◽  
Environmental Perturbations ◽  
Stream Macroinvertebrate ◽  
Path Analysis Approach

AbstractMoving beyond species count data is an essential step to better understand the effects of environmental perturbations on biodiversity and ecosystem functions, and to eventually better predict the strength and direction of those effects. Here, coupling an integrative path analysis approach with data from an extensive countrywide monitoring program, we tested the main spatial, environmental and anthropogenic drivers of change in stream macroinvertebrate trophic structure along the entire Swiss Rhine river catchment. Trophic structure was largely driven by inherent altitudinal variation influencing and cascading to regional scaled factors such as land use change and position in the riverine network, which, in turn, transformed local habitat structure variables. Those cascading effects across scales propagated through the biotic community, first affecting preys and, in turn, predators. Our results illustrate how seemingly less important factors can act as essential transmission belts, propagating through direct and indirect pathways across scales to generate the specific context in which each trophic group will strive or not, leading to characteristic landscape wide variations in trophic community structure.

scholarly journals Increase in abundance and species richness of flies (Diptera, Brachycera) in the Lake Engure Nature Park, Latvia: effects of climate warming?

2014 ◽  
Vol 68 (1-2) ◽  
pp. 46-67 ◽  
Author(s):  
Viesturs Melecis ◽  
Aina Karpa ◽  
Kristaps Vilks
Keyword(s):  
Species Richness ◽  
Climate Warming ◽  
Grassland Management ◽  
Moisture Regime ◽  
Positive Temperature ◽  
Large Herbivores ◽  
Long Term Ecological Research ◽  
Nature Park ◽  
Positive Correlations ◽  
June July

Abstract The article discusses changes in species richness and numbers of flies (Diptera, Brachycera) in the Lake Engure Nature Park (LENP) during 1995-2012. The study was performed within the framework of the National Long Term Ecological Research (LTER) network of Latvia. During the period of study, a statistically significant increase in positive temperature sums (> 4 °C) was observed at the local meteorological station (R2 = 0.489; P < 0.01). Insects were collected three times per season (June, July, and August) by entomological sweep net from twelve sample plots, which represented a variety of habitats of the LENP - dry xerophytic, mesophytic and humid hygrophytic ones. In total 411 species from 35 families were identified. Dry sample plots showed a statistically significant increase in species richness and/or numbers of flies during the period of study. Humid sample plots did not show any statistically significant trends except for two grassland plots where large herbivores were introduced in 2005 for grassland management purpose. Pooling the data from all sample plots, except those grazed by large herbivores, yielded a statistically significant trend of increase in species richness of flies (R2 = 0.647; P < 0.01). Among the main trophic groups zoophagous species showed the largest number of statistically significant positive trends mostly within the dry sample plots. For several sample plots significant positive correlations were recorded between species richness of zoophagous flies and annual sums of positive temperatures. It was hypothesised that climate warming may have an indirect effect via interaction with other environmental factors such as moisture regime, nitrogen pollution, and vegetation structure.

scholarly journals Assessing the occurrence of cyanotoxins in two urban reservoirs through a community science monitoring program

2021 ◽  
Author(s):  
◽  
Emily C. Kinzinger
Keyword(s):  
Water Quality ◽  
High School Students ◽  
Monitoring Program ◽  
Water Quality Monitoring ◽  
Quality Parameters ◽  
Cyanobacterial Blooms ◽  
Environmental Drivers ◽  
School Students ◽  
One Year ◽  
Community Science

Cyanobacterial blooms are an ongoing threat to aquatic systems worldwide. These potentially toxic blooms have typically been observed in summer to early fall, but there are increasing reports of blooms in colder seasons. From the few studies available, weknow that blooms can produce toxins in the winter. The objective of this research was to assess the year-round presence, concentration, and environmental drivers of the cyanotoxins microcystin and cylindrospermopsin in two reservoirs located in Columbia, Missouri, USA. To fulfill this objective, I coordinated and managed the Reservoir Observer Student Scientists (ROSS) program. This community science initiative combined educating high school students about limnology and cyanobacterial blooms with training students hands-on to collect weekly water quality samples. Data for this project was collected over two years in Bethel Lake and one year in Stephens Lake. We found detectable concentrations of the cyanotoxins year-round. There was no relationship between microcystin nor cylindrospermopsin and chlorophyll-a in either reservoir. Presence and concentration of microcystin and cylindrospermopsin were related to physical water quality parameters in Bethel Lake. This study provides evidence for the necessity of year-round water quality monitoring.

scholarly journals Species list of ground-dwelling ants (Hymenoptera: Formicidae) in the Nhecolândia, Pantanal, Mato Grosso do Sul, Brazil

2021 ◽  
Vol 61 ◽  
pp. e20216181
Author(s):  
Mila Ferraz de Oliveira Martins ◽  
Mariane Aparecida Nickele ◽  
Rodrigo Machado Feitosa ◽  
Marcio Roberto Pie ◽  
Wilson Reis-Filho
Keyword(s):  
Forest Regeneration ◽  
Species List ◽  
Mato Grosso ◽  
Pasture Area ◽  
Conservation Plans ◽  
First Time ◽  
Mato Grosso Do Sul ◽  
Dry And Rainy Seasons ◽  
Eleven Species ◽  
Anthropic Pressure

This study provides a list of the ground-dwelling ant species in Nhecolândia, Pantanal, Mato Grosso Sul, Brazil. The Pantanal is the largest tropical wetland in the world and is currently under strong anthropic pressure. Ground-dwelling ants were collected in three sites: (1) a forest regeneration area; (2) a pasture area; and (3) an area of secondary native vegetation. In each site, 120 samples were collected using pitfall traps in the dry and rainy seasons of 2016. Additional samplings were performed with Winkler extractors (30 leaf-litter samples) and manually, also in dry and rainy seasons of 2016. In total, we collected 172 species, which, summed with the additional records from literature, raise the number of ant species recorded in Nhecolândia to 184 in 42 genera and nine subfamilies. Eleven species were recorded for the first time in the state of Mato Grosso do Sul. Also, the survey adds two new species records to Brazil. Besides contributing to the inventory of the ant species present in the Pantanal biome, the present study provides an important resource for future conservation plans for this threatened ecoregion.

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