scholarly journals Diversity of Understory Communities in Boreal Forests: Influences of Forest Type, Latitude, and Spatial Scale

Forests ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 1003
Author(s):  
Yu-Song Jin ◽  
Yu-Kun Hu ◽  
Jing Wang ◽  
Dan-Dan Liu ◽  
Ying-Hua Lin ◽  
...  
Keyword(s):  
Beta Diversity ◽  
Boreal Forests ◽  
Forest Type ◽  
Critical Role ◽  
Understory Vegetation ◽  
Coniferous Forests ◽  
Lower Latitude ◽  
Forest Types ◽  
Vegetation Diversity ◽  
Alpha And Beta Diversity

Understory vegetation hosts high biodiversity and plays a critical role in the ecosystem processes of boreal forests. However, the drivers of understory plant diversity in this high-latitude ecosystem remain uncertain. To investigate the influences of forest type and latitude on understory beta diversity at different scales, we quantified the species composition of Vaccinium uliginosum Linnaeus communities under broadleaf and coniferous forests at two latitudes at the quadrat (2 × 2 m) and plot (10 × 10 m) scales in the Greater Xing’an Mountains, NE China. At the quadrat scale, species alpha diversity of V. uliginosum communities was higher in broadleaf forests than that in coniferous forests at both latitudes. The differences in species beta diversity (the Sørensen’s dissimilarity) in two forest types depended on the latitude: beta diversity in broadleaf forests was higher than that in coniferous forests at the higher latitude, while beta diversity in coniferous forests was higher at the lower latitude. At the plot scale, alpha and beta diversity of V. uliginosum communities decreased from broadleaf forests to coniferous forests at the higher latitude, and they did not show significant differences between forest types at the lower latitude. These results indicate the interactive effects of forest type and latitude on beta diversity of understory vegetation. Moreover, the influences of forest type and latitude on species alpha and beta diversity were different across the two spatial scales, suggesting that the assembly mechanisms underlying species diversity may be different at different scales. Understanding the maintenance of understory vegetation diversity will benefit the conservation and management of boreal forests.

scholarly journals Age structure of coniferous saplings in mountain old-growth forests of the Middle Urals

2021 ◽  
Vol 265 ◽  
pp. 01024
Author(s):  
Natalya Ivanova ◽  
Irina Petrova
Keyword(s):  
Old Age ◽  
Age Structure ◽  
Forest Type ◽  
Coniferous Forest ◽  
Pine Forests ◽  
Coniferous Forests ◽  
Middle Urals ◽  
Forest Types ◽  
Ural Mountains ◽  
The Middle Urals

The processes of natural reforestation play a crucial role for the preservation of primary coniferous forests and the success of their restoration after catastrophic impacts. The objective of our research was to identify the features of the natural renewal of the main coniferous forest-forming plants under the canopy of stands in the mountains of the Middle Urals, to establish dependencies on the forest type not only the total number of tree saplings, but also its age structure. The research was carried out in the mountainous part of the Sverdlovsk region (Russia) on the eastern macroslope of the Ural Mountains. We studied old-age pine forests, which belong to the 4 most common forest types. The tree saplings were counted into account on 2-4 subplots with a length of 20 meters and a width of 2 meters. It is established that under the canopy of all types of forest there is a different age coniferous saplings, despite significant differences in habitats. The most abundant pine saplings are found in pine forests with Vaccinium vitis-idaea, and the most abundant spruce saplings is found in pine forest with spruce and moss cover.

Overstory influences on light attenuation patterns and understory plant community diversity and composition in southern boreal forests of Quebec

2006 ◽  
Vol 36 (9) ◽  
pp. 2065-2079 ◽  
Author(s):  
Paula Bartemucci ◽  
Christian Messier ◽  
Charles D Canham
Keyword(s):  
Plant Community ◽  
Plant Communities ◽  
Boreal Forests ◽  
Forest Floor ◽  
Light Transmission ◽  
Forest Type ◽  
Light Attenuation ◽  
Understory Vegetation ◽  
Light Levels ◽  
Understory Plant

We have characterized overstory light transmission, understory light levels, and plant communities in mixed wood boreal forests of northwestern Quebec with the objective of understanding how overstory light transmission interacts with composition and time since disturbance to influence the diversity and composition of understory vegetation, and, in turn, the further attenuation of light to the forest floor by the understory. Overstory light transmission differed among three forest types (aspen, mixed deciduous–conifer, and old cedar-dominated), with old forests having higher proportions of high light levels than aspen and mixed forests, which were characterized by intermediate light levels. The composition of the understory plant communities in old forests showed the weakest correlation to overstory light transmission, although those forests had the largest range of light transmission. The strongest correlation between characteristics of overstory light transmission and understory communities was found in aspen forests. Species diversity indices were consistently higher in aspen forests but showed weak relationships with overstory light transmission. Light attenuation by the understory vegetation and total height of the understory vegetation were strongly and positively related to overstory light transmission but not forest type. Therefore, light transmission through the overstory influenced the structure and function of understory plants more than their diversity and composition. This is likely due to the strong effect of the upper understory layers, which tend to homogenize light levels at the forest floor regardless of forest type. The understory plant community acts as a filter, thereby reducing light levels at the forest floor to uniformly low levels.

Selection of den, rendezvous, and resting sites by wolves in the Bialowieza Forest, Poland

2003 ◽  
Vol 81 (1) ◽  
pp. 163-167 ◽  
Author(s):  
Jörn Theuerkauf ◽  
Sophie Rouys ◽  
Wlodzimierz Jedrzejewski
Keyword(s):  
Canis Lupus ◽  
Forest Type ◽  
Ground Cover ◽  
Habitat Characteristics ◽  
Coniferous Forests ◽  
Forest Edges ◽  
Forest Types ◽  
Resting Sites ◽  
Białowieża Forest ◽  
Selection Of

We studied wolf (Canis lupus) selection of 19 den, 10 rendezvous, and 31 resting sites found between 1986 and 2000 in the Bialowieza Forest (Poland). Our objective was to determine whether wolves selected sites far from villages, forest edges, and roads, and whether these sites had dense ground cover for concealment. We also tested whether wolves selected a particular forest type for their den sites. Den and rendezvous sites were located at greater distances from villages, forest edges, and intensively used roads than random points. Locations of resting sites were not affected by these manmade structures. Wolves selected dry coniferous forests for den sites but also used other forest types. We concluded that the suitability of an area for pup raising depended mainly on the spatial distribution of forest, human settlements, and public roads, and to a lesser extent on habitat characteristics.

scholarly journals Ranking Importance of Topographical Surface and Subsurface Parameters on Paludification in Northern Boreal Forests Using Very High Resolution Remotely Sensed Datasets

2020 ◽  
Vol 12 (2) ◽  
pp. 577 ◽  
Author(s):  
Ahmed Laamrani ◽  
Osvaldo Valeria
Keyword(s):  
High Resolution ◽  
Boreal Forests ◽  
Critical Role ◽  
Mineral Soil ◽  
Coniferous Forests ◽  
Slope Aspect ◽  
Limiting Factor ◽  
Organic Layer ◽  
Topographic Wetness Index ◽  
Variable Surface

The accumulation of organic material on top of the mineral soil over time (a process called paludification) is common in Northern Boreal coniferous forests. This natural process leads to a marked decrease in forest productivity overtime. Topography both at the surface of the forest floor (i.e., above ground) and the subsurface (i.e., top of mineral soil which is underground) is known to play a critical role in the paludification process. Until recently, the availability of more accurate topographic information regarding the surface and subsurface was a limiting factor for land management and modeling of spatial organic layer thickness (OLT) variability, a proxy for paludification. However so far, no research has assessed which of these two topographic variables has the greatest influence on paludification. This study aims to assess which topographic variable (surface or subsurface) better explains paludification, using high-resolution remote sensing technology (i.e., Light Detection and Ranging: LiDAR and Ground Penetrating Radar: GPR). To this end, field soil measurements were made in over 1614 sites distributed throughout the reference Valrennes Experimental site in Canadian northern coniferous forests. Then, a machine learning model (i.e., Random Forest, RF) was implemented to rank a set of selected predictor topographic variables (i.e., slope, aspect, mean curvature, plan curvature, profile curvature, and topographic wetness index) using the Mean Decrease Gini (MDG) index as an indicator of importance. Results showed that overall 83% of the overall variance was explained by the RF selected model, while the derived subsurface topography predictors had the lowest MDGs for predicting paludification. On the other hand, the surface slope predictor had the highest MDGs and better explained paludification. This finding would be particularly useful for implanting sustainable management strategies based on the surface variables of paludified northern boreal forests. This study has also highlighted the potential of LiDAR data to provide surface topographic spatial detail information for planning and optimizing forest management activities in paludified boreal forests. This is even of great importance when we know that LiDAR variables are easier to obtain compared to GPR derived variables (subsurface topographic variables).

Decomposition of broadleaf and needle litter in forests of British Columbia: influences of litter type, forest type, and litter mixtures

2000 ◽  
Vol 30 (11) ◽  
pp. 1742-1750 ◽  
Author(s):  
C E Prescott ◽  
L M Zabek ◽  
C L Staley ◽  
R Kabzems
Keyword(s):  
British Columbia ◽  
Populus Tremuloides ◽  
Picea Glauca ◽  
Boreal Forests ◽  
Forest Type ◽  
Douglas Fir ◽  
Coniferous Forests ◽  
Coastal Forests ◽  
Mixedwood Forests ◽  
Needle Litter

We measured rates of decomposition at three sites representing the major mixedwood forest types of British Columbia: (i) boreal forests of white spruce (Picea glauca (Moench) Voss) and trembling aspen (Populus tremuloides Michx.); (ii) coastal forests of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and red alder (Alnus rubra Bong.); and (iii) a wet interior forest of Douglas-fir, paper birch (Betula papyrifera Marsh.), and lodgepole pine (Pinus contorta Doug. ex Loud.). Mass loss of litter of each species (both pure and in combination with the other species) was measured for 2-5 years in forests of each species to determine (i) if broadleaf litter decomposed faster than needle litter, (ii) if litter decomposed faster in broadleaf or mixedwood forests than in coniferous forests, and (iii) if mixing with broadleaf hastened decomposition of needle litter. The broadleaf litters decomposed faster than needles during the first year but, thereafter, decomposed more slowly, so differences were small after 3 years. Litter tended to decompose faster in the broadleaf forests than in the coniferous forests. There was either no effect or a slight suppression of decomposition when litters were mixed; thus, there was no evidence that addition of broadleaf litter hastened decomposition of needle litter. The results clearly indicate that the mixing of needle litter with broadleaf litter is unlikely to hasten decomposition in mixedwood forests of British Columbia. The main influence of broadleaves was more rapid decomposition in broadleaf or mixedwood forest floors, which does not appear to be simply an effect of litter quality or litter mixing.

scholarly journals Site‐specific impacts of a major hurricane on alpha and beta diversity in tropical forest seedling communities

Ecosphere ◽  
2021 ◽  
Vol 12 (7) ◽  
Author(s):  
Samantha J. Worthy ◽  
Vanessa E. Rubio ◽  
Kirstin Staiger ◽  
Boris Ngouajio ◽  
Jie Yang ◽  
...  
Keyword(s):  
Tropical Forest ◽  
Beta Diversity ◽  
Site Specific ◽  
Alpha And Beta Diversity ◽  
Major Hurricane

scholarly journals Effect of Bovine MFGM and LF in Infant Formula on Gut Microbiome and Metabolome at Four Months of Age

2021 ◽  
Author(s):  
Maciej Chichlowski ◽  
Nicholas Bokulich ◽  
Cheryl L Harris ◽  
Jennifer L Wampler ◽  
Fei Li ◽  
...  
Keyword(s):  
Infant Formula ◽  
Beta Diversity ◽  
Milk Fat ◽  
Alpha Diversity ◽  
Illumina Miseq ◽  
Rrna Gene ◽  
Term Infants ◽  
Linear Discriminant ◽  
Alpha And Beta Diversity ◽  
Metabolite Profiles

Abstract Background Milk fat globule membrane (MFGM) and lactoferrin (LF) are human milk bioactive components demonstrated to support gastrointestinal (GI) and immune development. Significantly fewer diarrhea and respiratory-associated adverse events through 18 months of age were previously reported in healthy term infants fed a cow's milk-based infant formula with added source of bovine MFGM and bovine LF through 12 months of age. Objectives To compare microbiota and metabolite profiles in a subset of study participants. Methods Stool samples were collected at Baseline (10–14 days of age) and Day 120 (MFGM + LF: 26, Control: 33). Bacterial community profiling was performed via16S rRNA gene sequencing (Illumina MiSeq) and alpha and beta diversity were analyzed (QIIME 2). Differentially abundant taxa were determined using Linear discriminant analysis effect size (LefSE) and visualized (Metacoder). Untargeted stool metabolites were analyzed (HPLC/mass spectroscopy) and expressed as the fold-change between group means (Control: MFGM + LF ratio). Results Alpha diversity increased significantly in both groups from baseline to 4 months. Subtle group differences in beta diversity were demonstrated at 4 months (Jaccard distance; R2 = 0.01, P = 0.042). Specifically, Bacteroides uniformis and Bacteroides plebeius were more abundant in the MFGM + LF group at 4 months. Metabolite profile differences for MFGM + LF vs Control included: lower fecal medium chain fatty acids, deoxycarnitine, and glycochenodeoxycholate, and some higher fecal carbohydrates and steroids (P < 0.05). After applying multiple test correction, the differences in stool metabolomics were not significant. Conclusions Addition of bovine MFGM and LF in infant formula was associated with subtle differences in stool microbiome and metabolome by four months of age, including increased prevalence of Bacteroides species. Stool metabolite profiles may be consistent with altered microbial metabolism. Trial registration:  https://clinicaltrials.gov/ct2/show/NCT02274883).

scholarly journals The Fecal Bacterial Microbiota in Horses with Equine Recurrent Uveitis

Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 745
Author(s):  
Michelle Martin de Bustamante ◽  
Diego Gomez ◽  
Jennifer MacNicol ◽  
Ralph Hamor ◽  
Caryn Plummer
Keyword(s):  
Beta Diversity ◽  
High Throughput Sequencing ◽  
Illumina Miseq ◽  
Diversity Indices ◽  
Rrna Gene ◽  
Linear Discriminant ◽  
Alpha And Beta Diversity ◽  
Bacterial Microbiota ◽  
Healthy Control ◽  
Equine Recurrent Uveitis

The objective of this study was to describe and compare the fecal bacterial microbiota of horses with equine recurrent uveitis (ERU) and healthy horses using next-generation sequencing techniques. Fecal samples were collected from 15 client-owned horses previously diagnosed with ERU on complete ophthalmic examination. For each fecal sample obtained from a horse with ERU, a sample was collected from an environmentally matched healthy control with no evidence of ocular disease. The Illumina MiSeq sequencer was used for high-throughput sequencing of the V4 region of the 16S rRNA gene. The relative abundance of predominant taxa, and alpha and beta diversity indices were calculated and compared between groups. The phyla Firmicutes, Bacteroidetes, Verrucomicrobia, and Proteobacteria predominated in both ERU and control horses, accounting for greater than 60% of sequences. Based on linear discriminant analysis effect size (LEfSe), no taxa were found to be enriched in either group. No significant differences were observed in alpha and beta diversity indices between groups (p > 0.05 for all tests). Equine recurrent uveitis is not associated with alteration of the gastrointestinal bacterial microbiota when compared with healthy controls.

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