scholarly journals Leaf thermotolerance in tropical trees from a seasonally dry climate varies along the slow-fast resource acquisition spectrum

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Aniruddh Sastry ◽  
Deepak Barua
Author(s):  
J.A. Lancashire ◽  
J.L. Brock

Some characteristics of seed quality, establishment rates, performance in mixtures and response to grazing management of 5 new pasture plants with potential in dryland are described. On a dry hill country site in the Wairarapa, the contribution of the sown grasses established in separate plots with clovers under rotational grazing was 'Grasslands Wana' cocksfoot 65%; 'Grasslands Maru' phalaris 23%; 'Grasslands Matua' prairie grass 22%; and 'Grasslands Roa' tall fescue 13% after 2 years. The other main grass species was resident perennial ryegrass which established from buried seed (ca. 240 plants/m*) and had a major impact on the establishment and growth of the sown grasses. On a seasonally dry Manawatu flat land soil 3 grazing managementsviz. set stocked all year (S); rotational all year (R); and combination (Cl (set stocked from lambing to drafting and rotational for the remainder of the year) were applied to mixtures of the new cultivars (except that 'Grasslands Apanui' cocksfoot replaced Wana) with ryegrass and white clover stocked at 20 sheep/ha. After 3 years the contribution of the new cultivars was negligible under S and ryegrass was dominant. The R pastures became cocksfoot dominant and Matua (in winter) and chicory (in summer) contributed more than in the S system. The C system produced the most evenly balanced species contribution with only Roa remaining at (5%. A sub-trial with cocksfoot cultivars demonstrated that Wana maintained better production and tiller density ~ll,000/m2 ) than Apanui (1000/m' ) under set stocking IS). Although some of the new cultivars will require specialised management procedures to fulfil their potential in dryland, the increasing and widespread use of Matua prairie grass in farming suggests that these techniques can be adopted in commercial agriculture provided good technical information is available in a management package when the cultivar is released. Keywords: Dryland, grazing management, mixtures, Matua prairie grass, Wana cocksfoot, Roa tall fescue, Maru phalaris, Chicory


2018 ◽  
Vol 9 (1) ◽  
pp. 107-126
Author(s):  
Birgit Schneider

The article discusses how current mediated conditions change nature perception from a media study perspective. The article is based on different case studies such as the current sensation of atmospheric change through sensible media attached to trees which get published via Twitter, the meteorologist Amazonian Tall Tower Observatory and the use of gutta percha derived from tropical trees for the production of cables in the history of telegraphy. For analysing the examples, the perspective of »media as environments« is flipped to »environments as media«, because this focus doesn’t approach media from a networked and technological perspective primarily but makes productive the elemental character of basic »media« like air, earth and water


2018 ◽  
Vol 42 (4) ◽  
pp. 177-197
Author(s):  
Hee Young Lim ◽  
Na Young Kwon ◽  
Min Soo Kim

2018 ◽  
Author(s):  
Jon D. Richey ◽  
◽  
Joseph D. White ◽  
Isabel P. Montañez ◽  
Jonathan P. Wilson ◽  
...  

2019 ◽  
Author(s):  
Camila Martínez ◽  
◽  
Carlos Jaramillo ◽  
Jhonatan Martínez Murcia ◽  
Federico Moreno ◽  
...  

2020 ◽  
Vol 13 (1) ◽  
pp. 196
Author(s):  
Mengmeng Meng ◽  
Weiguo Fan ◽  
Jianchang Lu ◽  
Xiaobin Dong ◽  
Hejie Wei

Qinghai-Tibet Plateau is a typical resource-rich but economically backward region in western China, and it is of great urgency to improve human well-being. Combined with previous scholars’ research and the characteristics of Qinghai-Tibet Plateau, this paper constructs an index system of human well-being including four dimensions: income and consumption, means of production, means of subsistence, and resource acquisition ability. Then, it uses generalized matrix method estimations to measure the influence of energy utilization and economic development on human well-being and makes a regression analysis on the influence of energy utilization and economic development on human well-being in various provinces in this region. It is found that per capita GDP and coke utilization promote the well-being of all dimensions, while the urban registered unemployment rate only promotes the well-being of means of subsistence. The utilization of gasoline and natural gas promotes income and consumption and inhibits the means of subsistence and resource acquisition ability, but they have opposite effects on means of production. The impacts of energy utilization and economic development in different provinces on human well-being are different. This study is of great significance to the related research aiming at improving people’s livelihood and promoting regional development.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jorge Palomo-Kumul ◽  
Mirna Valdez-Hernández ◽  
Gerald A. Islebe ◽  
Manuel J. Cach-Pérez ◽  
José Luis Andrade

AbstractWe evaluated the effect of ENSO 2015/16 on the water relations of eight tree species in seasonally dry tropical forests of the Yucatan Peninsula, Mexico. The functional traits: wood density, relative water content in wood, xylem water potential and specific leaf area were recorded during the rainy season and compared in three consecutive years: 2015 (pre-ENSO conditions), 2016 (ENSO conditions) and 2017 (post-ENSO conditions). We analyzed tree size on the capacity to respond to water deficit, considering young and mature trees, and if this response is distinctive in species with different leaf patterns in seasonally dry tropical forests distributed along a precipitation gradient (700–1200 mm year−1). These traits showed a strong decrease in all species in response to water stress in 2016, mainly in the driest site. Deciduous species had lower wood density, higher predawn water potential and higher specific leaf area than evergreen species. In all cases, mature trees were more tolerant to drought. In the driest site, there was a significant reduction in water status, regardless of their leaf phenology, indicating that seasonally dry tropical forests are highly vulnerable to ENSO. Vulnerability of deciduous species is intensified in the driest areas and in the youngest trees.


Author(s):  
Junfan Yu ◽  
Saskia De Klerk ◽  
Michael Hess

AbstractThis research focuses on how entrepreneurs utilize cronyism to acquire resources. A case study method allowed us to explore three firms in the private property development industry in China. These firms uniquely cultivated cronyism and achieved distinctly different outcomes. Our findings highlight Chinese entrepreneurs in start-up ventures and later-stage enterprises employ cronyism. The underlying rationale for using cronyism have common and heterogeneous motivations. The similarity and distinguishing rationale also apply to the impact of cronyism. We also find two contingency working mechanisms for cronyism: entrepreneurial characteristics and a staged model for cronyism. With the firm’s growth, cronyism remains important, but firms with more community involvement outperform others. This research contributes to the theory on strategic network utilization for resource acquisition during entrepreneurial development stages. We investigate how entrepreneurial strategies can assist in adapting to the “rules of the game” while utilizing resources within the set contextual constraints.


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