Desenvolvimento Radicular de Macaúba (Acrocomia aculeata) em Dois Solos

O sistema radicular das plantas tem papel fundamental na absorção dos nutrientes e na sua sustentação. As palmeiras possuem raízes pouco profundas, mas oferecem grande aporte ao seu sustento. Suas raízes formam um aglomerado de raízes secundárias, terciárias e quaternárias constituindo um bom sistema de absorção de água e de nutrientes. O estudo de raízes é moroso, e em palmeiras é incipiente. O objetivo do presente trabalho foi avaliar o desenvolvimento radicular da Acrocomia aculeata ecotipo sclerocarpa em dois solos. O estudo foi desenvolvido na Universidade Estadual de Londrina, em vasos preenchidos com dois solos, Latossolo Vermelho eutroférrico (argiloso) e um Latossolo Vermelho distroférrico (arenoso), em telado. Avaliou-se o sistema radicular da macaúba a cada 90 dias se utilizando o programa Safira®. As variáveis avaliadas foram: volume (mm3), área (mm2), diâmetro (cm) e comprimento (mm) de raízes. A parte aérea também foi mensurada a cada 30 dias, em altura (cm), diâmetro do coleto (cm) e número de folhas. As plantas foram avaliadas até 360 dias. Verificou-se um aumento significativo, nos dois solos, para todas as variáveis. O sistema radicular no Latossolo Vermelho eutroférrico se desenvolveu melhor atingindo médias elevadas, exceto no comprimento. O Latossolo Vermelho distroférrico, aos 360 dias, obteve o maior comprimento de raízes. Na parte aérea, o solo arenoso se destacou em relação ao argiloso, mantendo suas médias constantes em altura, número de folhas e diâmetro. Palavras-chave: Sistema Radicular. Latossolo. sclerocarpa. AbstractThe plants’ root system plays a key role in the nutrients absorption in their support. Palm trees have shallow roots, but offer great contribution to their livelihood. Their roots form a cluster of secondary, tertiary and quaternary roots constituting a good system for absorbing water and nutrients. The study of roots is lengthy, and in palm trees, it is incipient. The objective of this study was to evaluate the root development of Acrocomia aculeata sclerocarpa ecotype in two soils. The study was conducted at the State University of Londrina, in pots filled with two soils, Oxisol (clayey) and an Oxisol (sandy), in greenhouse. The root system of macaw palm was evaluated every 90 days using the Safira® program. The variables evaluated were: volume (mm3), area (mm2), diameter (cm) and length (mm) of roots. The shoot was also measured every 30 days, height (cm), stem diameter (cm) and number of leaves. The plants were evaluated up to 360 days. There was a significant increase in both soils, for all the variables. The root system in Oxisol (clayey) developed better hitting high averages, except length. The Oxisol (sandy) at 360 days, had the highest root length. In the shoots, the sandy soil stood out compared to clay, maintaining its constant average height, leaf number and diameter. Keywords: Root system. Oxisol. sclerocarpa.

The ‘filtering’ metaphor revisited: competition and environment jointly structure invasibility and coexistence

‘Filtering’, or the reduction in species diversity that occurs because not all species can persist in all locations, is thought to unfold hierarchically, controlled by the environment at large scales and competition at small scales. However, the ecological effects of competition and the environment are not independent, and observational approaches preclude investigation into their interplay. We use a demographic approach with 30 plant species to experimentally test: (i) the effect of competition on species persistence in two soil moisture environments, and (ii) the effect of environmental conditions on mechanisms underlying competitive coexistence. We find that competitors cause differential species persistence across environments even when effects are lacking in the absence of competition, and that the traits which determine persistence depend on the competitive environment. If our study had been observational and trait-based, we would have erroneously concluded that the environment filters species with low biomass, shallow roots and small seeds. Changing environmental conditions generated idiosyncratic effects on coexistence outcomes, increasing competitive exclusion of some species while promoting coexistence of others. Our results highlight the importance of considering environmental filtering in the light of, rather than in isolation from, competition, and challenge community assembly models and approaches to projecting future species distributions.

Scots law’s debt to Leiden

The fact that Scotland, while still part of the United Kingdom, has its own legal system is not an accident. Nor is it just a product of its geography. Had it been so, the system would surely have had shallow roots. It would long ago have been completely absorbed into the legal system of its much bigger southern neighbour. As it is, Scots law was able to retain its own distinct institutions and identity in 1707 when the Union with England was entered into. This is because by then it had developed its own coherent system of law. It was a system with a sound jurisprudential base, and it could stand on its own feet. That Scotland was able to achieve this was in no small measure due to the inspiration that students from Scotland found when they travelled to Holland in search of education in the civil law the late 17th and early 18th centuries. The links that they established with the university at Leiden and some of its celebrated jurists during this period were particularly strong and productive. They helped to lay the foundation for the legal system that Scotland could assert as its own. This paper seeks to trace the history of this relationship, and to identify the extent to which its influence can still be found in Scots law as it exists today.

On Place, Time, and The Roots of Confucianism

This writing addresses a direct response to as well as shares a careful reflection with Ed Casey and Bob Neville, two of my longtime good friends, whom I invited to a panel I organized for Plenary Section 1, 11th East-West Philosophers’ Conference entitled “Place”, East-West Center, Honolulu, Hawai’i, May 25, 2017. It starts with the question of understanding the meaning of place for humanity and human development. To understand place as the birthplace of life and humanity is essential to understanding what a place is, because a place has to link to other places and to the whole of space as a totality of places. Places are developed historically and transferred to us with their values just like our own life comes to us in the development of our histories and cultures. This leads to the idea of a place as not separable from time. I have only addressed time to some extent in this paper, but I have introduced time as an essential part of our defining characterization of humanity and its resources. This then leads to our deep understanding of humanity as the creative product of time and space, which is derived from a common life origin: creativity. Throughout, I have also elaborated my thinking on the complex issue of “deep roots” and “shallow roots” of Confucianism, in light of inspirations from Bob Neville, who has raised important questions.

Efficient Rooting System for Apple “M.9” Rootstock Using Rice Seed Coat and Smocked Rice Seed Coat

“M.9” rootstock is considered as one of the most useful apple (MalusxdomesticaBorkh.) rootstocks; it produces dwarfing trees efficiently. As “M.9” rootstock shows a poor, brittle, and shallow roots system, we grafted “M.9” rootstocks onto “Marubakaidou” (M. prunifoliaBorkh. var. ringo Asami Mo 84-A). We then propagated them by mound layering to establish a high-density root system. It was found that covering the roots with rice seed coat (RSC), RSC + smoked rice seed coat (SRSC), and vermiculite during mound layering was effective for the initiation of rooting. Utilizing RSC and SRSC seemed especially effective for producing “M.9” roots efficiently.