Plant competition

In this review, we provide an overview of the role of glucosinolates and other phytochemical compounds present in the Brassicaceae in relation to plant protection and human health. Current knowledge of the factors that influence phytochemical content and profile in the Brassicaceae is also summarized and multi-factorial approaches are briefly discussed. Variation in agronomic conditions (plant species, cultivar, developmental stage, plant organ, plant competition, fertilization, pH), season, climatic factors, water availability, light (intensity, quality, duration) and CO(2) are known to significantly affect content and profile of phytochemicals. Phytochemicals such as the glucosinolates and leaf surface waxes play an important role in interactions with pests and pathogens. Factors that affect production of phytochemicals are important when designing plant protection strategies that exploit these compounds to minimize crop damage caused by plant pests and pathogens. Brassicaceous pl...

Arbuscular mycorrhizal (AM) symbioses are formed by approximately 80% of vascular plant species in all major terrestrial biomes. In consequence an understanding of their functions is critical in any study of sustainable agricultural or natural ecosystems. Here we discuss the implications of recent results and ideas on AM symbioses that are likely to be of particular significance for plants dealing with abiotic stresses such as nutrient deficiency and especially water stress. In order to ensure balanced coverage, we also include brief consideration of the ways in which AM fungi may influence soil structure, carbon deposition in soil and interactions with the soil microbial and animal populations, as well as plant-plant competition. These interlinked outcomes of AM symbioses go well beyond effects in increasing nutrient uptake that are commonly discussed and all require to be taken into consideration in future work designed to understand the complex and multifaceted responses of plants to abiotic and biotic stresses in agricultural and natural environments.

In this review, we provide an overview of the role of glucosinolates and other phytochemical compounds present in the Brassicaceae in relation to plant protection and human health. Current knowledge of the factors that influence phytochemical content and profile in the Brassicaceae is also summarized and multi-factorial approaches are briefly discussed. Variation in agronomic conditions (plant species, cultivar, developmental stage, plant organ, plant competition, fertilization, pH), season, climatic factors, water availability, light (intensity, quality, duration) and CO(2) are known to significantly affect content and profile of phytochemicals. Phytochemicals such as the glucosinolates and leaf surface waxes play an important role in interactions with pests and pathogens. Factors that affect production of phytochemicals are important when designing plant protection strategies that exploit these compounds to minimize crop damage caused by plant pests and pathogens. Brassicaceous pl...

For sustainable forest management, it is important to know the response of timber species to the change in environment caused by logging. We performed a 2-year study on germination, survival and growth of four timber species, Cedrela odorata, Swietenia macrophylla, Hymenaea courbaril, and Cariniana micrantha, and one non-commercial species Tachigali vasquezii. We sowed seeds of these species in five microenvironments:

The aim of this work was to introduce competition effects in the model underlying the analysis of forest tree experiments. Results were compared with analysis in which effects were neglected. Trials with different levels of precision and mortality were used, including the following species: Gallesia gorarema Vell. Moq., Eucalyptus grandis Hill ex Maiden, Eucalyptus citriodora Hook, Pinus elliottii Engl. var.

Шумските екосистеми се еден од најзначајните столбови на растителниот и животинскиот биодиверзитет, но нивната стабилност и одржливост често пати е загрозувана од различни биотски, антропогени или абиотски фактори. Во одредени случаи настанува и до целосно уништување на одреден шумски екосистем. Во таквите случаи многу чест и многу сериозен причинител се шумските пожари, кои за кусо време опожаруваат големи шумски површини и значително го нарушуваат или целосно уништуваат шумскиот екосистем. Сепак, способноста за природно обновување како карактеристика на шумската дендрофлора е значаен фактор за повторно воспоставување на шумска вегетација на опожарените шумски површини и целосна ревитализација на шумскиот екосистем. Целта на овој труд е да се утврдат основите природни сукцесивни процеси на шумската дрвенеста вегетација кои се појавуваат некоку години по силен шумски пожар од кој целосно е уништен шумскиот екосистем. Со проучувањето на појавата, развитокот, квалитативните и квантитативни карактеристики на единките од природната обнова се добиени податоци за можноста и успешноста на ревитализацијата на опожарениот шумски екосситем. За таа цел извршени се теренски истражувања преку директни мерења и проучувања на природната обнова со методот на пробни површини. Добиените резултати укажуваат на тоа дека опожарената шумска површина постепено се ревитализира, првенствено со пионерски видови од шумската дендрофлора, но за целосна ревитализација на шумскиот екосистем е потребен долг временски период.
The forest ecosystems are one of the most important foundations of the biological diversity concerning flora and fauna, but forest’s natural balance and sustainability are often on impact and influence by wide spectra of biotic, anthropogenic or abiotic factors. In specific circumstances, some of the forest ecosystems can be totally destroyed. Namely, the wildfires, in particular forest fires can cause enormous consequences and devastating impact on forest ecosystems; for short period of time forest fires can burn large forest mass and make the forest ecosystem an erasure. Even so, the forest vegetation has a very important and essential ability- the dendrofloral capacity for natural regeneration, both vegetative and by seed, and for a period of time to re-establish and implicitly rehabilitate, i.e. to grew up and become a forest as it once was. The main purpose of this scientific paper is to determine and note the basic natural succession processes of the forest dynamics after forest fire, particularly the natural regeneration of the forest woody species. Thus, determination of the appearance, development, qualitative and quantitative characteristics of the individuals in a natural regeneration process were made and the data base was analyzed to see the possibility and efficiency of the rehabilitation of the burned forest ecosystem. Therefore, field examinations were made using direct measurements and research of the presence of the natural regeneration; the method of the sample plats was used. The results indicate that burned forest area gradually and progressively regenerates, primarily with pioneer species of the forest dendroflora. After all, for complete rehabilitation of the forest ecosystem there is a need of a long period of time; eventually, the forest regenerates slowly, but assuredly.

This report documents impacts from manipulations of native forest soils and competing vegetation on development and ectomycorrhizal formation of outplanted western white pine and Douglas-fir in the Inland Northwest. Treatments were: 1) mounding surface horizons with competition left in place, 2) mounding surface horizons with subsequent physical or chemical control of competing vegetation, 3) scalping for control of competing vegetation,

Forest regeneration is a spatial multifaceted process with numerous unknown variables. The individual area or the area potentially available (APA) to an individual plant embodies an idea widely used in population ecology but it has fewer applications in forest research. It was used a Voronoi/ Thiessen tessellation in order to determine the individual area of each sapling. The study was conducted in a naturally regenerated area; using data collected from over seven thousands saplings positioned in a network of permanent rectangular sampling plots. The Voronoi/ Thiessen polygons were used to characterize spatial pattern of sapling distribution as well as the competition relations between the individuals. It is obvious that, at least from the mathematically point of view, the Voronoi tessellation represents one of the best solutions to determine neighbouring competitors of a tree. There were studied the correlations between APA values and the main biometrical attributes, height growth and competition indices. Furthermore, it is shown that APA coefficient of variation is a straight-forward indicator with positive results as an indicator of spatial pattern. The statistical significance of this indicator was evaluated by comparing the results with the values of a 95% confidence envelope generated by Monte-Carlo simulations. Two practical software tools were produced using Visual Basic (VORONOI and ARIA VORONOI) in order to simplify the analyses.