Relative importance of climate, vegetation, and spatial factors in the community and functional composition of wood-inhabiting fungi in discontinuously distributed subalpine spruce forests

2021 ◽  
pp. 1-10
Author(s):  
Yu Fukasawa ◽  
Kimiyo Matsukura ◽  
Yoko Ando ◽  
Satoshi N. Suzuki ◽  
Kunihiro Okano ◽  
...  

Wood-inhabiting fungi are critically important for the decomposition of coarse woody debris (CWD). To evaluate the relative importance of climate, vegetation, and spatial factors in the functional composition of fungal communities that inhabit CWD in discontinuously distributed subalpine Hondo spruce (Picea jezoensis (Sieb. & Zucc.) Carr. var. hondoensis (Mayr) Rehder) forests, a metabarcoding analysis was conducted on spruce deadwood samples obtained from six subalpine forests in central Japan using a high-throughput DNA sequencing technique. We detected 454 fungal operational taxonomic units (OTUs) from 67 spruce CWDs and determined that spatial factors explained a larger fraction of community variation than environmental (climate and vegetation) factors at all six study sites. However, environmental factors explained a larger fraction than spatial factors if we excluded data from one site that is geographically distant from other study sites. The OTU number and the occurrence of brown-rot fungi were positively associated with mean annual temperature and negatively associated with mean annual precipitation. Similarly, the principal component of forest vegetation significantly affected the OTU number and occurrence of brown-rot fungi. Precipitation seasonality was positively associated with the OTU number of undefined saprotrophs. These results suggest that fungal OTUs belonging to different functional groups respond differently to environmental variables.

2020 ◽  
Author(s):  
Lisa Zwanzig ◽  
Martin Zwanzig ◽  
Daniela Sauer

<p>Soil formation is controlled by climate, vegetation, organisms, topography, parent material and time. There are various hypotheses on the relative importance of these individual soil-forming factors. The quantitative influence of each soil-forming factor on the expression and rates of soil-forming processes, and in particular the influence of the different factors in combination, have not yet been sufficiently analyzed. The aim of this study was to quantify the influence of the soil-forming factors on the rates of podzolization. For this purpose, we compiled published data from 46 soil chronosequence studies in a database. These studies contained altogether 231 soil profiles of known age, on which we tested existing hypotheses on the influence of different soil-forming factors. The formation of an E horizon and its increase in thickness over time is one of the characteristic features of Podzol formation. As it is one of the few features that was described in all 46 studies, we used it as an indicator of progressive podzolization. Through statistical analysis, we investigated how E horizon thickness is affected by latitude, longitude, mean annual precipitation, mean annual temperature, range between minimum and maximum monthly temperature, annual number of days with frost, vegetation class (pioneer, deciduous and coniferous), sand content, clay content, and soil age.</p><p>Since E horizon thickness exhibited a zero-inflated (semi-)continuous distribution, we opted for a zero-altered gamma (ZAG) model, consisting of a Bernoulli and a Gamma part. The Bernoulli part shows, how the probability of the presence of an E horizon changes with soil age and environmental conditions. The Gamma part of the ZAG model allows for capturing the effects of the covariates on E horizon thickness. Our results indicate that vegetation is the most important factor for both (1) the soil age at which podzolization starts (used indicator: first occurrence of an E horizon), and (2) the rates of podzolization thereafter (used measure: increase of E horizon thickness with soil age). Climatic factors such as mean annual precipitation and range of temperature play subordinate roles. They are important for the soil age at which podzolization starts but less important for the rates of podzolization. We did not identify a significant influence of sand content, neither on the start nor the rates of podzolization. Thus, this statistical assessment of global data provides new insights into the relative importance of the individual soil-forming factors on the onset and temporal course of podzolization.</p>


2014 ◽  
Vol 281 (1784) ◽  
pp. 20133246 ◽  
Author(s):  
Juliano Sarmento Cabral ◽  
Patrick Weigelt ◽  
W. Daniel Kissling ◽  
Holger Kreft

Island biogeographic studies traditionally treat single islands as units of analysis. This ignores the fact that most islands are spatially nested within archipelagos. Here, we took a fundamentally different approach and focused on entire archipelagos using species richness of vascular plants on 23 archipelagos worldwide and their 174 constituent islands. We assessed differential effects of biogeographic factors (area, isolation, age, elevation), current and past climate (temperature, precipitation, seasonality, climate change velocity) and intra-archipelagic spatial structure (archipelago area, number of islands, area range, connectivity, environmental volume, inter-island distance) on plant diversity. Species diversity of each archipelago ( γ ) was additively partitioned into α , β , nestedness and replacement β -components to investigate the relative importance of environmental and spatial drivers. Multiple regressions revealed strong effects of biogeography and climate on α and γ , whereas spatial factors, particularly number of islands, inter-island distance and area range, were key to explain β . Structural equation models additionally suggested that γ is predominantly determined by indirect abiotic effects via its components, particularly β . This highlights that β and the spatial arrangement of islands are essential to understand insular ecology and evolution. Our methodological framework can be applied more widely to other taxa and archipelago-like systems, allowing new insights into biodiversity origin and maintenance.


2018 ◽  
Vol 4 (4) ◽  
pp. 229-238 ◽  
Author(s):  
A. Chemura ◽  
R. Musundire ◽  
L. Chiwona-Karltun

Edible insects present unique opportunities for food and nutrition security in many African communities. However, the characteristics of habitats and spatial distribution of edible insects is not known and yet it is important for understanding their ecology, planning harvesting and conservation activities in the wild. The edible ground cricket (Henicus whellani) Chopard (Orthoptera: Stenopelmatidae) is an edible insect consumed in south eastern Zimbabwe with protein content >50% on dry matter basis but harvesting is largely random and opportunistic. The aim of this study was to apply the Maximum Entropy (MaxEnt) presence-only species distribution modelling approach to understand the factors influencing distribution of H. whellani and map the potential areas for harvesting and conservation of the species. Geographical locations of sites where H. whellani is currently present were obtained from field reports from communities. Seven geographical factors which are mean annual temperature, temperature seasonality, mean annual precipitation, seasonality of precipitation, soil type, elevation, vegetation density and land cover were used to run the model. The model showed a high prediction accuracy for H. whellani (AUC=0.86) indicating that the model can be used with confidence to predict distribution and potential habitats in S.E Zimbabwe. Results showed that soil type (46.7%) and vegetation density (17.5%) are the most important factors determining the distribution of H. whellani. The hotspots for H. whellani were identified and closely followed specific soil and vegetation gradients in the area. The model considered temperature (3.9%) and elevation (0.6%) as the least important factors in H. whellani distribution. The produced distributed maps can be used for planning efficient harvesting and conservation of this nutritious edible insect in Zimbabwe.


2021 ◽  
Author(s):  
Yuxi Zhong ◽  
Chuanwu Chen ◽  
Yanping Wang

Abstract China is a country with one of the most species rich reptile faunas in the world. However, nearly a quarter of Chinese lizard species assessed by the China Biodiversity Red List are threatened. Nevertheless, to date, no study has explicitly examined the pattern and processes of extinction and threat in Chinese lizards. In this study, we conducted the first comparative phylogenetic analysis of extinction risk in Chinese lizards. We addressed the following three questions: 1) What is the pattern of extinction and threat in Chinese lizards? 2) Which species traits and extrinsic factors are related to their extinction risk? 3) How can we protect Chinese lizards based on our results? We collected data on ten species traits (body size, clutch size, geographic range size, activity time, reproductive mode, habitat specialization, habitat use, leg development, maximum elevation, and elevation range) and seven extrinsic factors (mean annual precipitation, mean annual temperature, mean annual solar insolation, normalized difference vegetation index (NDVI), human footprint, human population density, and human exploitation). After phylogenetic correction, these variables were used separately and in combination to assess their associations with extinction risk. We found that Chinese lizards with small geographic range, large body size, high habitat specialization, and living in high precipitation areas were vulnerable to extinction. Conservation priority should thus be given to species with the above extinction-prone traits so as to effectively protect Chinese lizards. Preventing future habitat destruction should also be a primary focus of management efforts because species with small range size and high habitat specialization are particularly vulnerable to habitat loss.


Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 668
Author(s):  
Justine Oma Angadam ◽  
Seteno Karabo Obed Ntwampe ◽  
Boredi Silas Chidi ◽  
Jun Wei Lim ◽  
Vincent Ifeanyi Okudoh

Human endeavors generate a significant quantity of bio-waste, even lignocellulosic waste, due to rapid industrialization and urbanization, and can cause pollution to aquatic ecosystems, and contribute to detrimental animal and human health because of the toxicity of consequent hydrolysis products. This paper contributes to a new understanding of the lignocellulosic waste bio-pretreatment process from a literature review, which can provide better biorefinery operational outcomes. The simultaneous partial biological lignin, cellulose and hemicellulose lysis, i.e., simultaneous semi-lignino-holocellulolysis, is aimed at suggesting that when ligninolysis ensues, holocellulolysis is simultaneously performed for milled lignocellulosic waste instead of having a sequential process of initial ligninolysis and subsequent holocellulolysis as is currently the norm. It is presumed that such a process can be solely performed by digestive enzyme cocktails from the monkey cups of species such as Nepenthes, white and brown rot fungi, and some plant exudates. From the literature review, it was evident that the pretreatment of milled lignocellulosic waste is largely incomplete, and ligninolysis including holocellulolysis ensues simultaneously when the waste is milled. It is further proposed that lignocellulosic waste pretreatment can be facilitated using an environmentally friendly approach solely using biological means. For such a process to be understood and applied on an industrial scale, an interdisciplinary approach using process engineering and microbiology techniques is required.


Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Liselotte De Ligne ◽  
Jan Van den Bulcke ◽  
Jan M. Baetens ◽  
Bernard De Baets ◽  
Gang Wang ◽  
...  

AbstractThe effect of fungicidal components in wood has been known for ages, yet there is no method to assess the impact of such components on the durability of a wood species, as compared to other material characteristics that influence decay. In this paper, the importance of fungicidal effects on the natural durability of 10 wood species is assessed in relation to other decay-influencing factors with a new test, the so-called ‘paste test’. By comparing results from this test with the ‘mini-block test’, on both heartwood and leached sapwood, insight is gained into the significance of fungicidal components on the one hand and other material characteristics on the other hand. The durability of species such as Prunus avium was attributed mainly to fungicidal components. For species such as Pterocarpus soyauxii, durability seemed to be an effect of both fungicidal components and moisture-regulating components, while the latter seemed to be of main importance in regulating the decay of Aucoumea klaineana and Entandrophragma cylindricum. Wood-anatomical features, such as the parenchyma content (in case of brown rot fungi) and the vessel-fiber ratio, possibly affect degradation as well. This work shows that fungicidal components are not always of major importance for the durability of a wood species. The authors hereby emphasize the importance of moisture-regulating components and wood anatomy on the durability of wood.


2021 ◽  
Author(s):  
A. L. Romero-Olivares ◽  
E. W. Morrison ◽  
A. Pringle ◽  
S. D. Frey

AbstractFungi are mediators of the nitrogen and carbon cycles in terrestrial ecosystems. Examining how nitrogen uptake and organic matter decomposition potential differs in fungi can provide insight into the underlying mechanisms driving fungal ecological processes and ecosystem functioning. In this study, we assessed the frequency of genes encoding for specific enzymes that facilitate nitrogen uptake and organic matter decomposition in 879 fungal genomes with fungal taxa grouped into trait-based categories. Our linked gene-trait data approach revealed that gene frequencies vary across and within trait-based groups and that trait-based categories differ in trait space. We present two examples of how this linked gene-trait approach can be used to address ecological questions. First, we show that this type of approach can help us better understand, and potentially predict, how fungi will respond to environmental stress. Specifically, we found that trait-based categories with high nitrogen uptake gene frequency increased in relative abundance when exposed to high soil nitrogen enrichment. Second, by comparing frequencies of nitrogen uptake and organic matter decomposition genes, we found that most ectomycorrhizal fungi in our dataset have similar gene frequencies to brown rot fungi. This demonstrates that gene-trait data approaches can shed light on potential evolutionary trajectories of life history traits in fungi. We present a framework for exploring nitrogen uptake and organic matter decomposition gene frequencies in fungal trait-based groups and provide two concise examples on how to use our framework to address ecological questions from a mechanistic perspective.


2021 ◽  
Vol 9 (2) ◽  
pp. 283
Author(s):  
Amelie Baomalgré Bougma ◽  
Korodjouma Ouattara ◽  
Halidou Compaore ◽  
Hassan Bismarck Nacro ◽  
Caleb Melenya ◽  
...  

In the more mesic savanna areas of West Africa, many areas of relatively tall and dense vegetation with a species composition more characteristic of forest than savanna are often found around villages areas. These ‘forest islands’ may be the direct action of human activity. To better understand these patches with relatively luxuriant vegetation, our study focused on how they influence soil aggregation in comparison with nearby areas and natural savanna vegetation across a precipitation transect in West Africa for which mean annual precipitation at the study sites ranges from 0.80 to 1.27 m a-1. Soil samples were taken from 0 to 5 cm and 5 to 10 cm depths and aggregate groups with diameters: > 500 μm, 500-250 μm and 250-53 μm (viz. “macroaggregates”, “mesoaggregates” and “microaggregates”) determined using the wet sieving method. The results showed significantly higher proportion of stable meso and macroaggregates in forest islands and natural savanna compared to agricultural soils (p <0.05). On the other hand, although there was no effect of land-use type on microaggregates stability, there was a strong tendency for the microaggregate fraction across all land use types to increase with increasing precipitation. Soil organic carbon and iron oxides contents are the most important factors influencing aggregate stability in West African ecosystems. By increasing soil structural stability, forest islands contribute to soil erosion reduction and the control of land degradation.


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