Can the mother plant age of Acacia melanoxylon (Leguminosae) modulate the germinative response to fire?

2017 ◽  
Vol 65 (7) ◽  
pp. 593 ◽  
Author(s):  
Oscar Cruz ◽  
Juan García-Duro ◽  
Mercedes Casal ◽  
Otilia Reyes

Acacia melanoxylon R.Br. (Leguminosae) is one of the most widely distributed tree species in the world. It has significant commercial use but can be a danger to natural ecosystems as an invader species. For these reasons it is necessary to have a deep knowledge about its germinative response to fire and the role the mother plant age plays in that response. In this work we assessed the effects of the interaction of the mother plant age with the main fire agents (smoke, charcoal, ash and heat) on the germinative response of A. melanoxylon. To reach this aim, germination tests were conducted with seeds from young, intermediate and mature mother plants, with 20 treatments each applied. Results show that fire can act as a great stimulator of the germination of A. melanoxylon but it can also strongly inhibit it. The mother plant age does not modify the final germination values, but it influences the time in which the first germinations occur after fire. This trait can be more important than the final germination percentage when looking at the success of post-fire regeneration. These results have important implications for A. melanoxylon management, for both species control and ecological restoration purposes.

2010 ◽  
Vol 19 (1) ◽  
pp. 15-22 ◽  
Author(s):  
Waldemar Żukowski ◽  
Agnieszka Bogdanowicz ◽  
Marlena Lembicz

Seed germination in sedges: a short reviewFive patterns of seed germination in the sedges of the genusCarexare presented, based on the literature data and the results of the authors' own research. They include the pattern ofC. acutiformis, C. arenaria, C. remota, C. flavaandC. communis. These patterns were constructed on the basis of seed specific requirements for development, such as stratification, temperature, dormancy and time of germination. Majority of sedges follow the pattern ofC. acutiformisorC. remota. In both cases, stratification and either high or low temperature are essential for seed germination. Seeds that start to germinate early (C. remotapattern) are characterized by the absence of the distinct peaks of germination, as opposed to theC. acutiformispattern with the germination peak in March. Our long-term investigations, conducted on the group of individuals in controlled conditions, revealed significant differences in seed size and the ability of seeds to germinate depending on the age of mother plants. We postulate that mother plant age is a new factor that should be considered in the construction of seed germination patterns.


HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 777A-777
Author(s):  
Yu Sung ◽  
D.J. Cantliffe ◽  
R.T. Nagata

Lettuce seeds differentially fail to germinate at temperatures above 21C according to genotype. Twenty-one lettuce lines were screened for their ability to germinate at temperatures from 24C to 36C. Four cultivars, `Dark Green Boston', `Valmaine', `Floricos 83', and `PI251245', were selected for this study because of their range of ability to germinate at temperatures above 24C. Seeds of the four cultivars were collected from mother plants grown in growth chambers at 20/10C(day/night temperature), 25/15C, 30/20C and 35/25C. Seeds were germinated on a thermogradient table from 24C to 36C under light (12 h). Seeds from `Floricos 83' produced above 30C had higher germination percentage at 33C and 36C than those produced below 30C temperatures. At 30C germination temperature seeds of `Valmaine' produced above 30C had 98% germination compared to 45% of those produced below 30C. `Dark Green Boston' seeds produced at 35C had higher germination percentage(70%) at 30C than those produced at other temperatures. Seeds collected from the mother plant grown above 30C day temperatures had greater germination than those grown below 30C.


2018 ◽  
Vol 100 (4) ◽  
pp. 745-766
Author(s):  
Lillian C. Woo

In the last fifty years, empirical evidence has shown that climate change and environmental degradation are largely the results of increased world population, economic development, and changes in cultural and social norms. Thus far we have been unable to slow or reverse the practices that continue to produce more air and water pollution, soil and ocean degradation, and ecosystem decline. This paper analyzes the negative anthropogenic impact on the ecosystem and proposes a new design solution: ecomimesis, which uses the natural ecosystem as its template to conserve, restore, and improve existing ecosystems. Through its nonintrusive strategies and designs, and its goal of preserving natural ecosystems and the earth, ecomimesis can become an integral part of stabilizing and rehabilitating our natural world at the same time that it addresses the needs of growing economies and populations around the world.


2017 ◽  
Vol 39 (4) ◽  
pp. 363-373 ◽  
Author(s):  
Jaciara de Souza Bispo ◽  
Danielle Carolina Campos da Costa ◽  
Samara Elizabeth Vieira Gomes ◽  
Gilmara Moreira de Oliveira ◽  
Janete Rodrigues Matias ◽  
...  

Abstract: Angico is a species found in several environments in Brazil, with several applications. It is used in the timber industry and mainly in folk medicine. In order to verify a variation in the biometric characteristics and the quality of seeds from different mother-plants in different harvesting years, the following variables were studied: moisture content, diameter, density, electrical conductivity, fresh and dry matter of seedlings, germination percentage and kinetics, in a completely randomized design with a 2x3 factorial arrangement (lots x size). The obtained results showed that angico seeds from different lots showed different physiological quality, possibly due to the climate variations to which mother-plants were submitted in the different years. Seed size directly interferes with seedling growth under both controlled and greenhouse conditions, and it can be used as a vigor indicator for angico seeds.


2018 ◽  
Vol 285 (1885) ◽  
pp. 20181049 ◽  
Author(s):  
Mauricio R. Bellon ◽  
Alicia Mastretta-Yanes ◽  
Alejandro Ponce-Mendoza ◽  
Daniel Ortiz-Santamaría ◽  
Oswaldo Oliveros-Galindo ◽  
...  

Maize evolution under domestication is a process that continues today. Case studies suggest that Mexican smallholder family farmers, known as campesinos , contribute importantly to this, but their significance has not been explicitly quantified and analysed as a whole. Here, we examine the evolutionary and food security implications of the scale and scope under which campesinos produce maize. We gathered official municipal-level data on maize production under rainfed conditions and identified campesino agriculture as occurring in municipalities with average yields of less than or equal to 3 t ha −1 . Environmental conditions vary widely in those municipalities and are associated with a great diversity of maize races, representing 85.3% of native maize samples collected in the country. We estimate that in those municipalities, around 1.38 × 10 11 genetically different individual plants are subjected to evolution under domestication each season. This implies that 5.24 × 10 8 mother plants contribute to the next generation with their standing genetic diversity and rare alleles. Such a large breeding population size also increases the total number of adaptive mutations that may appear and be selected for. We also estimate that campesino agriculture could potentially feed around 54.7 million people in Mexico. These analyses provide insights about the contributions of smallholder agriculture around the world.


1988 ◽  
Vol 66 (7) ◽  
pp. 1381-1390 ◽  
Author(s):  
J. Escarré ◽  
C. Houssard

Germination of Rumex acetosella L. was studied under a variety of experimental conditions to determine whether populations from old fields of different ages (fallow for 6 months to 15 years) differed in seed weight and germination rate and in plant biomass and flowering rate of the resulting plants. Fresh seeds collected from these natural populations showed differences in germination that varied with the date of harvest and the number of years since the field was last cultivated: seeds of the youngest population harvested in July germinated the best and were lighter than those of the other populations. Different fertilizer levels applied during the growth of the mother plants from seeds collected in the original old fields affected the mean weight and the germination rate of the resulting seeds, regardless of the density of cultivation of the mother plant. However, the effect of different fertilizer levels on mean seed weight varied with the origin of each population. Heavy seeds (mean weight > 0.6 mg) of mother plants from the populations of fields abandoned over 2 years ago germinated better than light seeds (mean weight < 0.6 mg). There was no significant difference between heavy and light seeds in terms of percent germination for seeds from mother plants that came from the "youngest" field. These differences in germination rate observed in field-collected seeds were also found in light seeds of the offspring generation: light seeds of the mother plant from the population belonging to the more recently abandoned old field germinated the best. Plants grown from heavy seeds that came from the other populations of older fields had more biomass than those resulting from light seeds. This difference has not been observed between individuals resulting from light and heavy seeds of the youngest population. On the other hand, these individuals had a higher flowering rate than those resulting from the older populations. These results are interpreted in relation to the successional status of the populations: high flowering and early germination rates are suitable characteristics for establishment of plants on bare ground or after a disturbance, whereas heavy seeds with more reserves ensure germination and enough biomass of the resulting plants in density-dependent conditions.


1970 ◽  
Author(s):  
Victor de Biasi ◽  
J. W. Sawyer

Reviews the world trends since 1966 in the application of gas turbines on both naval and merchant ships. States that the total horsepower increased from 1.9 to 5.8 million in a four-year period, with some 5.5 million horsepower in propulsion. Indicates a definite growth in commercial use from 100,000 to 390,000 hp. Attributes the significant gain in total power due primarily to the availability of proven engines, that are competitive with other prime movers, in the 20,000 hp and above size. Predicts significant increase in use of the marine gas turbine for naval as well as merchant ships when the overall ship, its utilization and supporting shore facilities are considered jointly.


Author(s):  
An Cliquet ◽  
Afshin Akhtar-Khavari

The concept of remedies has always been an important component of the legal system. Throughout the world, countries have utilized environmental law in a variety of ways to legislate for the remediation and rehabilitation of destroyed or degraded land and ecosystems. For example, in some countries, environmental law has provided for the remediation of contaminated mine sites, which can rather be classified as environmental restoration. However, often these countries have yet to properly enforce such law. Furthermore, given the significant increase in anthropogenic harm during the past few decades, there is an increasing realization that more needs to be done than simply acting to protect an environment from harm. Unlike the terms “rehabilitation” and “remediation,” the term “restoration” is drawn from the science of restoration ecology. The Society for Ecological Restoration (SER) defines ecological restoration as “the process of assisting the recovery of an ecosystem that has been degraded, damaged, or destroyed.” Ecological restoration contributes to the application of the ecosystem approach. There are different approaches to ecological and ecosystem recovery, such as rewilding or extreme forms of restoration such as “de-extinction.” This is due to the inherent complexity of assisting nature to recover from anthropogenic harm. Ecological restoration is the most prominent practice among ecologists to restore ecosystems, but is not the only approach. The main focus here will be on ecosystem restoration. “Restoration ecology” is the broad name for the scientific discipline behind ecological restoration and other recovery initiatives, and is a relatively new but rapidly developing branch within the study of natural sciences. Even more recently, there has been increasing legal attention to ecological restoration. There is no separate instrument in international law dealing with ecological restoration. However, legal obligations for restoration can be found in various multilateral environmental agreements, regional conventions, regional instruments such as European Union (EU) directives, and soft law instruments. The 1992 Convention on Biological Diversity (Biodiversity Convention) is an important convention outlining State party obligations for ecological restoration, as can be seen in both the Convention text and subsequent Conference of Parties decisions, including the 2010 Aichi Targets, which detail a specific target for ecological restoration. Prior to the Biodiversity Convention, the international community utilized the 1971 Ramsar Convention on Wetlands of International Importance especially as Waterfowl Habitat (Ramsar Convention) to introduce the concept of restoration. Other conventions that address ecological restoration or species restoration include the 1972 UNESCO Convention Concerning the Protection of the World Cultural and Natural Heritage (World Heritage Convention), the 1979 Bonn Convention on the Conservation of Migratory Species of Wild Animals (Convention on Migratory Species), and several of its additional agreements. Climate change poses both opportunities and additional challenges for restoration. Restoring ecosystems such as forests and peatlands assists in the reduction of carbon in the atmosphere. Within the framework of the United Nations Framework Convention on Climate Change (UNFCCC 1992) and the 2015 Paris Agreement, the role of restoration has been recognized. As various conventions and soft law instruments now impress obligations of restoration, the legal duty to restore the environment has matured into a customary obligation and can be considered as an emerging legal principle. However, most instruments containing legal obligations for restoration do not contain a clear definition or further clarification on how a State party might restore an ecosystem.


Flora ◽  
2011 ◽  
Vol 206 (2) ◽  
pp. 158-163 ◽  
Author(s):  
Marlena Lembicz ◽  
Paweł Olejniczak ◽  
Waldemar Żukowski ◽  
Agnieszka M. Bogdanowicz
Keyword(s):  

2020 ◽  
Author(s):  
Miriam Muñoz-Rojas ◽  
Paulo Pereira

&lt;p&gt;Fire is an essential element of the environment and a vital force for shaping landscapes all around the world. It has a critical role as driver of natural ecosystem processes and many plant communities are fire dependent aros the globe. However, although fire is a natural and regular component of some biomes in the Earth&amp;#8217;s systems, it can become a destructive force when natural ecosystems are disturbed, fire is introduced at a rate not previously experienced, and recovery to a pre-fire state is not possible. Thus, assesing the potentially harmful environmental impacts of fire and building the underlying knowledge required to successfully manage fire makes are crucial in order to understand the role of fire in all its different dimensions. Over the past year, fires in California in the United States and in the Amazon rainforest in Brazil have grabbed the world&amp;#8217;s attention. The increased rates of fire events in some of these areas, mostly attributed to land degradation processes, have led to international concern. More recently, several bushfires all around Australia have had dramatic impacts in the environment with 10 million hectares burned so far, including large portions of the natural environment. These unprecedented fires are predicted to affect to a large extent the soil characteristics, processes and function in several ecosystems. In this presentation, we highlight some of the most recent research published during the last year on the effects of fire on soil functions and the provision of soil ecosystem services. We also showcase some of the possible approaches to protect and conserve soil ecosystems affected by extreme fires and propose available strategies for post-fire management.&lt;/p&gt;


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