Drought‐induced reductions in plant defenses: Insights from extrafloral nectaries in the Caatinga dry forest

Biotropica ◽  
2021 ◽  
Author(s):  
Talita Câmara ◽  
Daniela Queiroz de Assis Reis ◽  
Xavier Arnan ◽  
Fernanda Maria Pereira Oliveira ◽  
Emília Cristina Pereira Arruda ◽  
...  

2020 ◽  
Vol 4 (1) ◽  
Author(s):  
Daniel M. Cáceres ◽  
Esteban Tapella ◽  
Diego A. Cabrol ◽  
Lucrecia Estigarribia

Argentina is experiencing an expansion of soya and maize cultivation that is pushing the agricultural frontier over areas formerly occupied by native Chaco forest. Subsistance farmers use this dry forest to raise goats and cattle and to obtain a broad range of goods and services. Thus, two very different and non-compatible land uses are in dispute. On the one hand subsistance farmers fostering an extensive and diversified forest use, on the other hand, large-scale producers who need to clear out the forest to sow annual crops in order to appropriate soil fertility. First, the paper looks at how these social actors perceive Chaco forest, what their interests are, and what kind of values they attach to it. Second, we analyze the social-environmental conflicts that arise among actors in order to appropriate forest’s benefits. Special attention is paid to the role played by the government in relation to: (a) how does it respond to the demands of the different sectors; and (b) how it deals with the management recommendations produced by scientists carrying out social and ecological research. To put these ideas at test we focus on a case study located in Western Córdoba (Argentina), where industrial agriculture is expanding at a fast pace, and where social actors’ interests are generating a series of disputes and conflicts. Drawing upon field work, the paper shows how power alliances between economic and political powers, use the institutional framework of the State in their own benefit, disregarding wider environmental and social costs. 



2020 ◽  
Vol 45 (4) ◽  
pp. 833-838
Author(s):  
Lamarck Rocha ◽  
Patrícia Luz Ribeiro ◽  
Maria Mercedes Arbo

Abstract—We present a new species, Turnera fasciculifolia, from the Jalapão region, the largest continuous protected area of Cerrado in Tocantins State, in central Brazil. The new species belongs to Turnera series Leiocarpae, and it can be recognized by the linear ericoid leaves with revolute margin, generally without extrafloral nectaries, and the basal leaves of the young axillary branches gathered in fascicles. We provide a description, illustrations, a distribution map, and a comparison with T. genistoides and T. revoluta, which also have ericoid leaves.



2004 ◽  
Vol 155 (3-4) ◽  
pp. 80-88 ◽  
Author(s):  
Klaus Ackermann

Wild growing yams (Dioscorea spp.) are an important supplementary food in Madagascar, especially during periods of rice shortage in the rainy season. Yams grow in dry forests and there is a particularly high occurrence of yam tubers in recently burned, open secondary forest formations. The study found that the uncontrolled harvest of yams can contribute to the degradation of dry forests due to the high quantity of wild yams harvested by the local population and the widespread practice of intentionally burning forests to increase yams production.



Mycotaxon ◽  
2018 ◽  
Vol 133 (3) ◽  
pp. 499-512 ◽  
Author(s):  
Magdalena Contreras-Pacheco ◽  
Ricardo Valenzuela ◽  
Tania Raymundo ◽  
Leticia Pacheco


Water ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 105
Author(s):  
Argelia E. Rascón-Ramos ◽  
Martín Martínez-Salvador ◽  
Gabriel Sosa-Pérez ◽  
Federico Villarreal-Guerrero ◽  
Alfredo Pinedo-Alvarez ◽  
...  

Understanding soil moisture behavior in semi-dry forests is essential for evaluating the impact of forest management on water availability. The objective of the study was to analyze soil moisture based in storm observations in three micro-catchments (0.19, 0.20, and 0.27 ha) with similar tree densities, and subject to different thinning intensities in a semi-dry forest in Chihuahua, Mexico. Vegetation, soil characteristics, precipitation, and volumetric water content were measured before thinning (2018), and after 0%, 40%, and 80% thinning for each micro-catchment (2019). Soil moisture was low and relatively similar among the three micro-catchments in 2018 (mean = 8.5%), and only large rainfall events (>30 mm) increased soil moisture significantly (29–52%). After thinning, soil moisture was higher and significantly different among the micro-catchments only during small rainfall events (<10 mm), while a difference was not noted during large events. The difference before–after during small rainfall events was not significant for the control (0% thinning); whereas 40% and 80% thinning increased soil moisture significantly by 40% and 53%, respectively. Knowledge of the response of soil moisture as a result of thinning and rainfall characteristics has important implications, especially for evaluating the impact of forest management on water availability.



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