Litter mass and nitrogen disappearance in year‐round nitrogen‐fertilized grass and legume‐grass forage systems

2021 ◽  
Author(s):  
Liliane Severino da Silva ◽  
Lynn E. Sollenberger ◽  
Marta Moura Kohmann ◽  
José C. Dubeux ◽  
Parmeshwor Aryal ◽  
...  
Keyword(s):  
Crop Science ◽  
2021 ◽  
Author(s):  
David M. Jaramillo ◽  
Jose C. B. Dubeux ◽  
Lynn Sollenberger ◽  
Cheryl Mackowiak ◽  
Joao M. B. Vendramini ◽  
...  

Pedobiologia ◽  
2019 ◽  
Vol 75 ◽  
pp. 38-51 ◽  
Author(s):  
Eduardo Nascimento ◽  
Filipa Reis ◽  
Filipe Chichorro ◽  
Cristina Canhoto ◽  
Ana Lúcia Gonçalves ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bruno Simmen ◽  
Luca Morino ◽  
Stéphane Blanc ◽  
Cécile Garcia

AbstractLife history, brain size and energy expenditure scale with body mass in mammals but there is little conclusive evidence for a correlated evolution between life history and energy expenditure (either basal/resting or daily) independent of body mass. We addressed this question by examining the relationship between primate free-living daily energy expenditure (DEE) measured by doubly labeled water method (n = 18 species), life history variables (maximum lifespan, gestation and lactation duration, interbirth interval, litter mass, age at first reproduction), resting metabolic rate (RMR) and brain size. We also analyzed whether the hypometabolic primates of Madagascar (lemurs) make distinct energy allocation tradeoffs compared to other primates (monkeys and apes) with different life history traits and ecological constraints. None of the life-history traits correlated with DEE after controlling for body mass and phylogeny. In contrast, a regression model showed that DEE increased with increasing RMR and decreasing reproductive output (i.e., litter mass/interbirth interval) independent of body mass. Despite their low RMR and smaller brains, lemurs had an average DEE remarkably similar to that of haplorhines. The data suggest that lemurs have evolved energy strategies that maximize energy investment to survive in the unusually harsh and unpredictable environments of Madagascar at the expense of reproduction.


1999 ◽  
Vol 77 (3) ◽  
pp. 370-376 ◽  
Author(s):  
Heather R Kleb ◽  
Scott D Wilson

Few studies have compared scales of heterogeneity among plant communities. We predicted that differences in the sizes of dominant species should allow us to detect small-scale (<256 cm) heterogeneity in mixed-grass prairie but not in adjacent aspen forest. We examined light penetration, soil moisture, available N, elevation, species composition, and plant mass at 10 locations in prairie and forest in both spring and summer. Variables were measured in 1-cm2 plots arranged in pairs separated by 0-256 cm. Several variables in prairie (elevation, litter mass, light penetration, and species composition) showed significant evidence for scale within the range examined. In contrast, only one variable in forest (light penetration in summer) showed evidence for scale in the same range. The scale of heterogeneity in prairie was consistent with the scale of two possible causes, species composition and elevation variability due to northern pocket gopher (Thomomys talpoides Richardson) activity, both of which varied significantly in prairie but not in forest. Whereas some aboveground factors (light and litter mass) varied within the range examined, belowground factors (water and N) did not, suggesting that the scale of heterogeneity differs between above- and below-ground factors. In total, the results suggest that differences in the scale of heterogeneity between prairie and forest reflect the relative sizes of the dominant plants.Key words: aspen, forest, heterogeneity, light, nitrogen, prairie, scale, soil, water.


Tropics ◽  
2018 ◽  
Vol 27 (2) ◽  
pp. 33-48
Author(s):  
Yoshiyuki Kiyono ◽  
Eriko Ito ◽  
Yukako Monda ◽  
Jumpei Toriyama ◽  
Thy Sum

2013 ◽  
Vol 43 (12) ◽  
pp. 1127-1136 ◽  
Author(s):  
Björn Berg ◽  
Björn Erhagen ◽  
Maj-Britt Johansson ◽  
Lars Vesterdal ◽  
Mikaeel Faituri ◽  
...  

The aim of the present synthesis paper was to determine whether concentration changes and net release of manganese (Mn), as related to accumulated litter mass loss, are related to initial Mn concentration, mean annual temperature (MAT), mean annual precipitation (MAP), and tree genus or species. We also examined whether limit values for decomposition are related to initial litter Mn concentration, MAT, and MAP. We compiled 84 foliar litter decomposition studies, conducted mainly in boreal and temperate forest ecosystems, for which Mn dynamics had been well documented. Manganese concentration and amount were related to accumulated litter mass loss at each sampling time for each single study, as well as for (i) all studies combined (n = 748) and (ii) for species groups viz. Norway spruce (Picea abies (L.) Karst.) (n = 284), pine (Pinus) species (n = 330), and deciduous species (n = 214). The changes in Mn concentration with accumulated mass loss followed quadratic functions showing significantly higher Mn concentrations for Norway spruce vs. Scots pine (Pinus sylvestris L.) (p < 0.0001) and vs. deciduous species (p < 0.01), as well as significantly higher for deciduous species vs. Scots pine (p < 0.0001). Manganese release rates were different among the three species groups (p < 0.001). Still, rates were related to initial Mn concentrations (p < 0.001) for all litter types combined and for the three species groups. Norway spruce released Mn more slowly than pine and deciduous species. Rates were related to climatic factors for litter of Norway spruce and deciduous species. Limit values for all litter and for pine species separately were related to Mn (p < 0.001) and MAT (p < 0.001). For Norway spruce, limit values were related to MAT (p < 0.001) and MAP (p < 0.01). It appears that Norway spruce litter retains Mn more strongly in the litter structure, producing humus richer in Mn than does litter of pine and deciduous species.


2010 ◽  
Vol 56 (No. 6) ◽  
pp. 278-284 ◽  
Author(s):  
B. Agherkakli ◽  
A. Najafi ◽  
S.H. Sadeghi

In this study, the effects of slope and traffic intensity on soil compaction, rutting and forest floor removal was evaluated on a skid trail in the natural forest of north of Iran. Combination of two levels of slope &lt; 20% (SC1) and &gt; 20% (SC2) and three levels of traffic (one, five and nine traffics) were studied. Treatment plots, with three replications, were established on the skid trail prior to skidding. The results of this study showed that all bulk densities were considerably higher in SC2 than in SC1 and average soil bulk densities were measured from 1.07 (g∙cm<sup>&ndash;3</sup>) to 1.23 (g∙cm<sup>&ndash;3</sup>) on skid trail and 0.91 (g∙cm<sup>&ndash;3</sup>) in undisturbed areas. With the increment of traffic, soil compaction increased but there was no significant difference among the three levels of traffic frequency in SC1 whereas it was significant between one and five cycles in SC2. Greatest rut depth was measured as 12 cm at nine traffics in SC2, although increase of traffic density caused deeper rut depth at all slope treatments, but it was higher at the SC2 in comparison to SC1. Litter mass decreased considerably on the skid trail with the increasing in slope and traffic. No important difference has been detected between SC1 and SC2 in terms of Litter mass removal. These results provide clear evidence that soil disturbance on steep trail is intensified.


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