Species-specific allometric scaling under self-thinning: evidence from long-term plots in forest stands

Oecologia ◽  
2005 ◽  
Vol 146 (4) ◽  
pp. 572-583 ◽  
Author(s):  
Hans Pretzsch
1996 ◽  
Vol 2 (3) ◽  
pp. 265-274 ◽  
Author(s):  
A. GRANIER ◽  
P. BIRON ◽  
N. BREDA ◽  
J.-Y. PONTAILLER ◽  
B. SAUGIER

2017 ◽  
Vol 10 (2) ◽  
pp. 49-62 ◽  
Author(s):  
Petr Maděra ◽  
Tomáš Slach ◽  
Luboš Úradníček ◽  
Jan Lacina ◽  
Linda Černušáková ◽  
...  

Abstract Ancient coppice woodlands are coppice-originated forest stands with a long-term continual development, and with the preserved typical natural and historic elements of old sprout forests. Prominent natural elements in the ancient coppice woodlands are namely old coppice stools. There is, in scientific literature, lack of information about features of ancient coppice stools. Therefore, our contribution aims to describe shape and form of ancient coppice stools, including the most important microhabitat of coppice woodlands – dendrothelms. Based on field survey of 20 localities of important coppice woodlands we recorded 135 ancient coppice stools of 13 tree species and a total of 80 dendrothelms in 9 tree species. Basic features of ancient coppice stools and dendrothlems were measured and evaluated.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7330
Author(s):  
Teemu Saikkonen ◽  
Varpu Vahtera ◽  
Seppo Koponen ◽  
Otso Suominen

The effect of reindeer Rangifer tarandus L. grazing on the ground-dwelling spider assemblage in Northern Finland was studied. Changes in species richness, abundance and evenness of spider assemblages were analyzed in relation to changes in vegetation and environmental factors in long term grazed and ungrazed sites as well as sites that had recently switched from grazed to ungrazed and vice versa. Grazing was found to have a significant impact on height and biomass of lichens and other ground vegetation. However, it seemed not to have an impact on the total abundance of spiders. This is likely caused by opposing family and species level responses of spiders to the grazing regime. Lycosid numbers were highest in grazed and linyphiid numbers in ungrazed areas. Lycosidae species richness was highest in ungrazed areas whereas Linyphiidae richness showed no response to grazing. Four Linyphiidae, one Thomisidae and one Lycosidae species showed strong preference for specific treatments. Sites that had recovered from grazing for nine years and the sites that were grazed for the last nine years but were previously ungrazed resembled the long term grazed sites. The results emphasize the importance of reindeer as a modifier of boreal forest ecosystems but the impact of reindeer grazing on spiders seems to be family and species specific. The sites with reversed grazing treatment demonstrate that recovery from strong grazing pressure at these high latitudes is a slow process whereas reindeer can rapidly change the conditions in previously ungrazed sites similar to long term heavily grazed conditions.


2016 ◽  
Vol 24 (1) ◽  
pp. 161-169 ◽  
Author(s):  
Sasha Engelmann

A spider’s web is the species-specific production of spacetime; it is an aesthetic as well as an evolutionary, metabolic and climatic achievement. As part of a long-term engagement with spiders and their webs, the artist Tomás Saraceno has collaborated with populations of spiders and other creatures to produce hybrid webs. The processual and patterned production of hybrid webs at Studio Tomás Saraceno inspires thought on the axes of more-than-human sympoeisis, on collaboration between and across multitudes of creatures, and on a spectrum of social and semi-social encounter between different species. Through interviews, storytelling, visual material and critical description, this paper develops a notion of hybrid webs as philosophical-aesthetic propositions for multispecies sociality.


Diversity ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 306
Author(s):  
Maurizio Rossetto ◽  
Peter D. Wilson ◽  
Jason Bragg ◽  
Joel Cohen ◽  
Monica Fahey ◽  
...  

Ecological restoration requires balancing levels of genetic diversity to achieve present-day establishment as well as long-term sustainability. Assumptions based on distributional, taxonomic or functional generalizations are often made when deciding how to source plant material for restoration. We investigate this assumption and ask whether species-specific data is required to optimize provenancing strategies. We use population genetic and environmental data from five congeneric and largely co-distributed species of Acacia to specifically ask how different species-specific genetic provenancing strategies are based on empirical data and how well a simple, standardized collection strategy would work when applied to the same species. We find substantial variability in terms of patterns of genetic diversity and differentiation across the landscape among these five co-distributed Acacia species. This variation translates into substantial differences in genetic provenancing recommendations among species (ranging from 100% to less than 1% of observed genetic variation across species) that could not have been accurately predicted a priori based on simple observation or overall distributional patterns. Furthermore, when a common provenancing strategy was applied to each species, the recommended collection areas and the evolutionary representativeness of such artificially standardized areas were substantially different (smaller) from those identified based on environmental and genetic data. We recommend the implementation of the increasingly accessible array of evolutionary-based methodologies and information to optimize restoration efforts.


2009 ◽  
Vol 37 (04) ◽  
pp. 250-260 ◽  
Author(s):  
D. Crossley ◽  
E. Boehmer

Summary Objective: Objective interpretation of dental disease in rabbits, guinea pigs and chinchillas with the use of anatomical reference lines. Material and methods: Skull radiographs (laterolateral and dorsoventral view) of 528 small mammals (204 rabbits, 151 guinea pigs and 173 chinchillas) were measured and analysed exactly in connection with a thorough intra- and extraoral clinical examination. 464 animals showed variable signs of malocclusion whereas 64 animals had a normocclusion. The clinical and radiographic changes of 224 individuals (52 rabbits, 41 guinea pigs and 131 chinchillas) were additionally compared with post mortem findings. Results: Particularly the comparison of the prepared skulls with the radiographs of the identical animals enabled the acquirement of species specific anatomical reference lines, that facilitate the objectice assessment of severity of dental disease in elodont species. Conclusion and clinical relevance: Using these reference lines the extent of malocclusion in rabbits, guinea pigs and chinchillas can be acquired more exactly and the results are reproducible by different examiners (staging). In addition to this these special lines facilitate to accurately monitor the progress of dental changes and thus to predict a probable long-term prognosis. The reference lines are absolutely applicable for daily use in practice.


2012 ◽  
Vol 52 (No. 10) ◽  
pp. 474-481 ◽  
Author(s):  
S. Vacek ◽  
V. Podrázský ◽  
M. Hejcman ◽  
J. Remeš

Norway spruce yellowing and defoliation caused by Mg deficiency was frequently recorded on many sites of the &Scaron;umava Mts. (Bohemian Forest Mts.) since 1980&rsquo;s. A forest experiment aimed at investigation response of spruce to Mg application (commercial fertilizer SILVAMIX<sup>&reg;</sup> Mg NPK) was set up in 1998. Fertilizer was applied manually in a dose of 96.5 kg Mg/ha in spruce (S) and beech-spruce (BS) vegetation altitudinal zones in spring 2000. Immediate decrease of yellowing was revealed in fertilized plots in both vegetation zones and yellowing almost completely disappeared at the end of the investigation in 2005. Further, fertilization resulted in stabile foliation while marked defoliation was reported from control plots in both vegetation zones. Mg deficiency can be effectively eliminated by appropriate fertilizer application. Balanced nutrition contributes to long-term vigour and stability of forest stands.


2011 ◽  
Vol 41 (6) ◽  
pp. 1295-1307 ◽  
Author(s):  
Robert P. Long ◽  
Stephen B. Horsley ◽  
Thomas J. Hall

Sugar maple (Acer saccharum Marsh.) is a keystone species in the northern hardwood forest, and decline episodes have negatively affected the growth and health of sugar maple in portions of its range over the past 50+ years. Crown health, growth, survival, and flower and seed production of sugar maple were negatively affected by a widespread decline event in the mid-1980s on the unglaciated Allegheny Plateau in northern Pennsylvania. A long-term liming study was initiated in 1985 to evaluate responses to a one-time application of 22.4 Mg·ha–1 of dolomitic limestone in four northern hardwood stands. Over the 23-year period ending in 2008, sugar maple basal area increment (BAINC) increased significantly (P ≤ 0.05) in limed plots from 1995 through 2008, whereas American beech (Fagus grandifolia Ehrh.) BAINC was unaffected. For black cherry (Prunus serotina Ehrh.), the third principal overstory species, BAINC and survival were reduced in limed plots compared with unlimed plots. Foliar Ca and Mg remained significantly higher in sugar maple foliage sampled 21 years after lime application, showing persistence of the lime effect. These results show long-term species-specific responses to lime application.


1993 ◽  
Vol 80 (3) ◽  
pp. 209-221 ◽  
Author(s):  
Per Warfvinge ◽  
Ursula Falkengren-Grerup ◽  
Harald Sverdrup ◽  
Bent Andersen
Keyword(s):  

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