The biomarker method: How organic soil chemistry and inverse modeling help unravel upper forest line dynamics in the Ecuadorian Andes

2009 ◽  
Vol 6 (7) ◽  
pp. 072030
Author(s):  
Boris Jansen ◽  
F Tonneijck ◽  
E Van Loon ◽  
K Verstraten ◽  
H Hooghiemstra
2009 ◽  
Vol 39 (6) ◽  
pp. 1069-1079 ◽  
Author(s):  
I.A. Dickie ◽  
S.J. Richardson ◽  
S.K. Wiser

The composition of ectomycorrhizal (EcM) fungal communities in Nothofagus rainforests and the responses of the fungal communities to timber harvesting have been unknown. We investigated EcM communities in two sites, 9 to 11 years after timber harvesting, and tested whether changes in the communities were driven by soil chemistry. The fungal communities in both sites were highly diverse, yet 53 out of 140 distinct terminal restriction fragment length polymorphism (T-RFLP) patterns were shared between the sites. At both sites, timber harvesting reduced the presence of EcM roots and caused shifts in the fungal community in the organic soil horizons. At one site, Laccaria spp. increased in harvested areas, which partially correlated with an increase in soil mineralizable nitrogen. The other site showed a decreased abundance of Russula sp. (cf. R. purpureotincta , R. roseostipitata ) in harvested areas, which correlated with declines in soil carbon and organic horizon depth, and a decline in the abundance of rare species at the edge of harvested areas, which was related to inorganic phosphorus. The results show that EcM fungal communities in Nothofagus temperate rainforest are highly diverse at the local scale, yet have a high degree of similarity across sites. These communities are directly affected by timber harvesting and by shifts in soil chemistry following timber harvesting.


2017 ◽  
Vol 4 (2) ◽  
pp. 87-91
Author(s):  
Ekamaida Ekamaida

The soil fertility aspect is characterized by the good biological properties of the soil. One important element of the soil biological properties is the bacterial population present in it. This research was conducted in the laboratory of Microbiology University of Malikussaleh in the May until June 2016. This study aims to determine the number of bacterial populations in soil organic and inorganic so that can be used as an indicator to know the level of soil fertility. Data analysis was done by T-Test that is by comparing the mean of observation parameter to each soil sample. The sampling method used is a composite method, which combines 9 of soil samples taken from 9 sample points on the same plot diagonally both on organic soil and inorganic soil. The results showed the highest bacterial population was found in total organic soil cfu 180500000 and total inorganic soil cfu 62.500.000


Author(s):  
W. R. EMANUEL ◽  
J. S. OLSON ◽  
W. M. POST ◽  
A. G. STANGENBERGER ◽  
P. J. ZINKE

Author(s):  
W. R. EMANUEL ◽  
J. S. OLSON ◽  
W. M. POST ◽  
A. G. STANGENBERGER ◽  
P. J. ZINKE

Author(s):  
W. R. EMANUEL ◽  
J. S. OLSON ◽  
W. M. POST ◽  
A. G. STANGENBERGER ◽  
P. J. ZINKE

2020 ◽  
Vol 54 (4) ◽  
pp. 403-431
Author(s):  
Bulat R. Rakhimzianov

Abstract This article explores relations between Muscovy and the so-called Later Golden Horde successor states that existed during the fifteenth and sixteenth centuries on the territory of Desht-i Qipchaq (the Qipchaq Steppe, a part of the East European steppe bounded roughly by the Oskol and Tobol rivers, the steppe-forest line, and the Caspian and Aral Seas). As a part of, and later a successor to, the Juchid ulus (also known as the Golden Horde), Muscovy adopted a number of its political and social institutions. The most crucial events in the almost six-century-long history of relations between Muscovy and the Tatars (13–18th centuries) were the Mongol invasion of the Northern, Eastern and parts of the Southern Rus’ principalities between 1237 and 1241, and the Muscovite annexation of the Kazan and Astrakhan khanates between 1552 and 1556. According to the model proposed here, the Tatars began as the dominant partner in these mutual relations; however, from the beginning of the seventeenth century this role was gradually inverted. Indicators of a change in the relationship between the Muscovite grand principality and the Golden Horde can be found in the diplomatic contacts between Muscovy and the Tatar khanates. The main goal of the article is to reveal the changing position of Muscovy within the system of the Later Golden Horde successor states. An additional goal is to revisit the role of the Tatar khanates in the political history of Central Eurasia in the fifteenth and sixteenth centuries.


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