Wood-decaying fungi in boreal forest: are species richness and abundances influenced by small-scale spatiotemporal distribution of dead wood?

Abstract Great attention has been drawn to the impacts of habitat deforestation and fragmentation on wildlife species richness. In contrast, much less attention has been paid to assessing the impacts of chronic anthropogenic disturbance on wildlife species composition and behaviour. We focused on natural small rock pools (sartenejas), which concentrate vertebrate activity due to habitat’s water limitation, to assess the impact of chronic anthropogenic disturbance on the species richness, diversity, composition, and behaviour of medium and large-sized birds and mammals in the highly biodiverse forests of Calakmul, southern Mexico. Camera trapping records of fauna using sartenejas within and outside the Calakmul Biosphere Reserve (CBR) showed that there were no effects on species richness, but contrasts emerged when comparing species diversity, composition, and behaviour. These effects differed between birds and mammals and between species: (1) bird diversity was greater outside the CBR, but mammal diversity was greater within and (2) the daily activity patterns of birds differed slightly within and outside the CBR but strongly contrasted in mammals. Our study highlights that even in areas supporting extensive forest cover, small-scale chronic anthropogenic disturbances can have pervasive negative effects on wildlife and that these effects contrast between animal groups.

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Rehabilitating boreal forest structure and species composition in Finland through logging, dead wood creation and fire: The EVO experiment

Forest Ecology and Management ◽

10.1016/j.foreco.2007.03.012 ◽

2007 ◽

Vol 250 (1-2) ◽

pp. 77-88 ◽

Cited By ~ 89

Author(s):

I. Vanha-Majamaa ◽

S. Lilja ◽

R. Ryömä ◽

J.S. Kotiaho ◽

S. Laaka-Lindberg ◽

...

Keyword(s):

Species Composition ◽

Boreal Forest ◽

Forest Structure ◽

Dead Wood

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Microwave snow emission modeling uncertainties in boreal and subarctic environments

The Cryosphere Discussions ◽

10.5194/tcd-9-5719-2015 ◽

2015 ◽

Vol 9 (5) ◽

pp. 5719-5773

Author(s):

A. Roy ◽

A. Royer ◽

O. St-Jean-Rondeau ◽

B. Montpetit ◽

G. Picard ◽

...

Keyword(s):

Grain Size ◽

Spatial Variability ◽

Boreal Forest ◽

Frozen Soil ◽

Microwave Emission ◽

Small Scale ◽

Radiometric Measurements ◽

Snow Properties ◽

Modeling Uncertainties

Abstract. This study aims to better understand and quantify the uncertainties in microwave snow emission models using the Dense Media Radiative Theory-Multilayer model (DMRT-ML) with in situ measurements of snow properties. We use surface-based radiometric measurements at 10.67, 19 and 37 GHz in boreal forest and subarctic environments and a new in situ dataset of measurements of snow properties (profiles of density, snow grain size and temperature, soil characterization and ice lens detection) acquired in the James Bay and Umijuaq regions of Northern Québec, Canada. A snow excavation experiment – where snow was removed from the ground to measure the microwave emission of bare frozen ground – shows that small-scale spatial variability in the emission of frozen soil is small. Hence, variability in the emission of frozen soil has a small effect on snow-covered brightness temperature (TB). Grain size and density measurement errors can explain the errors at 37 GHz, while the sensitivity of TB at 19 GHz to snow increases during the winter because of the snow grain growth that leads to scattering. Furthermore, the inclusion of observed ice lenses in DMRT-ML leads to significant improvements in the simulations at horizontal polarization (H-pol) for the three frequencies (up to 20 K of root mean square error). However, the representation of the spatial variability of TB remains poor at 10.67 and 19 GHz at H-pol given the spatial variability of ice lens characteristics and the difficulty in simulating snowpack stratigraphy related to the snow crust. The results also show that for ground-based radiometric measurements, forest emission reflected by the surface leads to TB underestimation of up to 40 K if neglected. We perform a comprehensive analysis of the components that contribute to the snow-covered microwave signal, which will help to develop DMRT-ML and to improve the required field measurements. The analysis shows that a better consideration of ice lenses and snow crusts is essential to improve TB simulations in boreal forest and subarctic environments.

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Rocky pine forests in the High Coast Region in Sweden: structure, dynamics and history

Nature Conservation ◽

10.3897/natureconservation.38.34870 ◽

2020 ◽

Vol 38 ◽

pp. 101-130

Author(s):

Jennie Sandström ◽

Mattias Edman ◽

Bengt Gunnar Jonsson

Keyword(s):

Human Impact ◽

Fire History ◽

Dead Wood ◽

Forest Type ◽

Basal Area ◽

Pine Forests ◽

Small Scale ◽

Natural Dynamics ◽

Almost All ◽

High Degree

Almost all forests in Sweden are managed and only a small fraction are considered natural. One exception is low productive forests where, due to their limited economical value, natural dynamics still dominate. One example is the Scots pine (Pinus sylvestris L.) forests occurring on rocky and nutrient-poor hilltops. Although these forests represent a regionally common forest type with a high degree of naturalness, their dynamics, structure and history are poorly known. We investigated the structure, human impact and fire history in eight rocky pine forests in the High Coast Area in eastern Sweden, initially identified as good representatives of this forest type. This was done by sampling and measuring tree sizes, -ages, fire-scarred trees, as well as dead wood volumes and quality along three transects at each site. The structure was diverse with a sparse layer of trees (basal area 9 m2 and 640 trees larger than 10 cm ha-1) in various sizes and ages; 13 trees ha-1 were more than 300 years old. Dead wood (DW), snags and logs in all stages of decay, was present and although the actual DW (pine) volume (4.4 m3 ha-1) and number of units (53 ha-1) was low, the DW share of total wood volume was 18% on average. Dead wood can be present for several centuries after death; we found examples of both snags and logs that had been dead more than 300 years. Frequent fires have occurred, with an average cycle of 40 years between fires. Most fires occurred between 1500-1900 and many of them (13) during the 1600s. However, fires were probably small since most fire years were only represented at one site and often only in one or a few samples. The rocky pine forests in the High Coast Area are representative of undisturbed forests with low human impact, exhibiting old-growth characteristics and are valuable habitats for organisms connected to sun-exposed DW. Management of protected rocky pine forests may well include small-scale restoration fires and the limited DW volumes should be protected.

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Environmental conditions alter successional trajectories on an ephemeral resource: a field experiment with beetles in dead wood

Oecologia ◽

10.1007/s00442-020-04750-5 ◽

2020 ◽

Vol 194 (1-2) ◽

pp. 205-219

Author(s):

Ole Petter Laksforsmo Vindstad ◽

Tone Birkemoe ◽

Rolf Anker Ims ◽

Anne Sverdrup-Thygeson

Keyword(s):

Species Richness ◽

Community Structure ◽

Ambient Temperature ◽

Dead Wood ◽

Species Turnover ◽

Experimental Studies ◽

Developmental Rate ◽

Fungal Community Composition ◽

Species Richness And Abundance ◽

Ephemeral Resources

Abstract Successional processes can be observed for many organisms and resources, but most studies of succession have focused on plants. A general framework has been proposed, advocating that successional patterns in species turnover are predominantly driven by competition, dispersal or abiotic limitation, and that the patterning of species accumulation over time gives clues to which process is most influential in a given system. We applied this framework to succession in communities of wood-living beetles, utilizing ephemeral resources in the form of 60 experimentally created dead aspen high stumps. High stumps were created at sun-exposed sites (high ambient temperature; favourable abiotic conditions) and shaded sites (low ambient temperature; abiotically limiting conditions). The sites were intermixed, ensuring similar dispersal opportunities. Beetle species richness and abundance were monitored with flight interception traps over four consecutive years. Consistent with predictions from the tested framework, several beetle functional groups accumulated species more slowly at the unfavourable shaded sites than at the favourable exposed sites. Species richness at the exposed sites increased rapidly to a plateau, consistent with a limiting effect of competition on community development. Similar results were obtained for beetle abundance and community structure. Part of the variance in beetle community structure was jointly explained by habitat and fungal community composition, suggesting that differences in the composition and developmental rate of fungal communities in the two habitats contributed to the observed patterns. Targeted experimental studies are now required to decisively establish what processes underlie the contrasting successional trajectories in the two environments.

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Testing biodiversity theory using species richness of reef-building corals across a depth gradient

Biology Letters ◽

10.1098/rsbl.2019.0493 ◽

2019 ◽

Vol 15 (10) ◽

pp. 20190493 ◽

Cited By ~ 2

Author(s):

T. Edward Roberts ◽

Sally A. Keith ◽

Carsten Rahbek ◽

Tom C. L. Bridge ◽

M. Julian Caley ◽

...

Keyword(s):

Species Richness ◽

Large Scale ◽

Coral Species ◽

Environmental Gradients ◽

Abiotic Factors ◽

Empirical Support ◽

Null Model ◽

Local Scale ◽

Small Scale ◽

Energy Availability

Natural environmental gradients encompass systematic variation in abiotic factors that can be exploited to test competing explanations of biodiversity patterns. The species–energy (SE) hypothesis attempts to explain species richness gradients as a function of energy availability. However, limited empirical support for SE is often attributed to idiosyncratic, local-scale processes distorting the underlying SE relationship. Meanwhile, studies are also often confounded by factors such as sampling biases, dispersal boundaries and unclear definitions of energy availability. Here, we used spatially structured observations of 8460 colonies of photo-symbiotic reef-building corals and a null-model to test whether energy can explain observed coral species richness over depth. Species richness was left-skewed, hump-shaped and unrelated to energy availability. While local-scale processes were evident, their influence on species richness was insufficient to reconcile observations with model predictions. Therefore, energy availability, either in isolation or in combination with local deterministic processes, was unable to explain coral species richness across depth. Our results demonstrate that local-scale processes do not necessarily explain deviations in species richness from theoretical models, and that the use of idiosyncratic small-scale factors to explain large-scale ecological patterns requires the utmost caution.

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