Impact of Mammals on Early Recruitment of a Tropical Canopy Tree, Dipteryx panamensis, in Panama

Oikos ◽  
1984 ◽  
Vol 43 (2) ◽  
pp. 207 ◽  
Author(s):  
Diane De Steven ◽  
Francis E. Putz
Keyword(s):  
Canopy Tree ◽  
Dipteryx Panamensis ◽  
Early Recruitment

scholarly journals Redox and Src family kinase signaling control leukocyte wound attraction and neutrophil reverse migration

2014 ◽  
Vol 207 (5) ◽  
pp. 589-598 ◽  
Author(s):  
Sebastien Tauzin ◽  
Taylor W. Starnes ◽  
Francisco Barros Becker ◽  
Pui-ying Lam ◽  
Anna Huttenlocher
Keyword(s):  
Tissue Regeneration ◽  
Tissue Damage ◽  
Redox Signaling ◽  
Kinase Signaling ◽  
Src Family Kinase ◽  
Reverse Migration ◽  
Early Recruitment

Tissue damage induces early recruitment of neutrophils through redox-regulated Src family kinase (SFK) signaling in neutrophils. Redox-SFK signaling in epithelium is also necessary for wound resolution and tissue regeneration. How neutrophil-mediated inflammation resolves remains unclear. In this paper, we studied the interactions between macrophages and neutrophils in response to tissue damage in zebrafish and found that macrophages contact neutrophils and induce resolution via neutrophil reverse migration. We found that redox-SFK signaling through p22phox and Yes-related kinase is necessary for macrophage wound attraction and the subsequent reverse migration of neutrophils. Importantly, macrophage-specific reconstitution of p22phox revealed that macrophage redox signaling is necessary for neutrophil reverse migration. Thus, redox-SFK signaling in adjacent tissues is essential for coordinated leukocyte wound attraction and repulsion through pathways that involve contact-mediated guidance.

scholarly journals Forest carbon sink neutralized by pervasive growth-lifespan trade-offs

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
R. J. W. Brienen ◽  
L. Caldwell ◽  
L. Duchesne ◽  
S. Voelker ◽  
J. Barichivich ◽  
...  
Keyword(s):  
Tree Growth ◽  
Tree Mortality ◽  
Carbon Sink ◽  
Growth Stimulation ◽  
Forest Carbon ◽  
System Model ◽  
Earth System ◽  
Canopy Tree ◽  
Trade Offs ◽  
Almost All

Abstract Land vegetation is currently taking up large amounts of atmospheric CO2, possibly due to tree growth stimulation. Extant models predict that this growth stimulation will continue to cause a net carbon uptake this century. However, there are indications that increased growth rates may shorten trees′ lifespan and thus recent increases in forest carbon stocks may be transient due to lagged increases in mortality. Here we show that growth-lifespan trade-offs are indeed near universal, occurring across almost all species and climates. This trade-off is directly linked to faster growth reducing tree lifespan, and not due to covariance with climate or environment. Thus, current tree growth stimulation will, inevitably, result in a lagged increase in canopy tree mortality, as is indeed widely observed, and eventually neutralise carbon gains due to growth stimulation. Results from a strongly data-based forest simulator confirm these expectations. Extant Earth system model projections of global forest carbon sink persistence are likely too optimistic, increasing the need to curb greenhouse gas emissions.

Flowering phenology and flower predation of Cullenia exarillata (Bombacaceae) by arboreal vertebrates in Western Ghats, India

1997 ◽  
Vol 13 (3) ◽  
pp. 459-468 ◽  
Author(s):  
T. Ganesh ◽  
Priya Davidar
Keyword(s):  
Western Ghats ◽  
Keystone Species ◽  
Flowering Phenology ◽  
Dry Season ◽  
Community Level ◽  
Canopy Tree ◽  
Southern Western Ghats ◽  
Annual Period

ABSTRACTThe flowering phenology and flower predation of Cullenia exarillata, a canopy tree at Kakachi in the southern Western Ghats, India, was studied from 1991 to 1993 in relation to general phenological patterns at the community level. Flowering was monitored from 30 marked trees and flower predation estimated from fallen flowers in 40, 1 m2 nets placed under the trees. Flowering occurs in the dry season and coincides with the period of fruit scarcity in the forest. Flowering is synchronous in the population and each tree produces a mean of c. 8730 flowers per tree over a period of c. 47 d. Flowers produced little nectar but the edible fleshy sepals compensated for this. Six species of arboreal mammals and seven species of birds ate the flowers. These consumed 57% of the flower crop of which 37% were completely destroyed. Flower predators could be important in flower fertilization. The overabundance of the flower crop and the timing of flowering, may have evolved as a strategy to satiate predators and enable the flowers to be pollinated during the annual period of fruit scarcity in the forest. This in turn makes Cullenia exarillata a possible keystone species in this forest.

scholarly journals Dynamics and Edge Effect of an Atlantic Forest Fragment in Brazil

2016 ◽  
Vol 23 (3) ◽  
pp. 340-349 ◽  
Author(s):  
Poliana Gabriella Araújo Mendes ◽  
Maria Amanda Menezes Silva ◽  
Tassiane Novacosque Feitosa Guerra ◽  
Ana Carolina Borges Lins-e-Silva ◽  
Airton de Deus Cysneiros Cavalcanti ◽  
...  
Keyword(s):  
Species Richness ◽  
Atlantic Forest ◽  
Edge Effect ◽  
Woody Plants ◽  
Response Times ◽  
Forest Edge ◽  
Northeastern Brazil ◽  
Forest Fragment ◽  
Canopy Tree ◽  
Forest Interior

ABSTRACT The woody plants in an edge area formed approximately 35 years ago in an Atlantic Forest fragment in northeastern Brazil were examined, and three environments defined: edge, intermediate, and interior. Canopy tree densities and basal areas were found to be similar in all three environments, and also similar to previous published studies in the same region; species richness was greatest at the forest edge. The understory showed greater species richness in the forest interior, but greater diversity and equitability in the intermediate environment. Understory environments close to the forest edge demonstrated larger stem diameters than in the forest interior, although at lesser densities and with smaller total basal areas. Our results indicated the existence of distinct patterns in canopy and understory that most likely reflect differences in the response times of these two vegetation layers, with the understory being more sensitive to alterations in environmental structure.

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