How species respond to environmental variation can have important consequences for population and community dynamics. Temperature, in particular, is one source of variation expected to strongly influence plant performance. Here, we compared photosynthetic responses to temperature across a guild of winter annual plants. Previous work in this system identified a trade-off between relative growth ...

BACKGROUND Photoperiodic control of development plays a key role in adaptation of plants to seasonal changes. A signaling module consisting of CONSTANS (CO) and FLOWERING LOCUS T (FT) mediates in photoperiodic control of a variety of developmental transitions (e.g., flowering, tuberization, and seasonal growth cessation in trees). How this conserved CO/FT module can mediate in the photoperiodic...

This dissertation describes work I conducted in collaboration with many others to examine the response of cloud forest ecosystems to global change and the role that photosynthetic pathways play in the carbon cycle. In the second chapter, my co-authors (Pru Foster and Stephen Schneider) and I examine the potential impacts of climate change on tropical montane cloud forests. These forests are cri...

To describe plant phenological patterns and correlate functioning for the quantity and quality of resources available for the pollinator, it is crucial to understand the temporal dynamics of biological communities. In this way, the pollination syndromes of 46 species with different growth habits (trees, shrubs, herbs, and vines) were examined in an area of Caatinga vegetation, northeastern Braz...

Subalpine grasslands are highly seasonal environments and likely subject to strong variability in nitrogen (N) dynamics. Plants and microbes typically compete for N acquisition during the growing season and particularly at plant peak biomass. During snowmelt, plants could potentially benefit from a decrease in competition by microbes, leading to greater plant N uptake associated with active gro...

Sage (Salvia libanotica) is an East Mediterranean plant, the extract of which is used for the treatment of colds, coughs, and stomach ache. Experimental studies on the toxicity of its oil are scarce despite its wide use in traditional medicine. This study aims to provide data on its acute toxicity and to investigate the relationship between seasonal changes in oil composition and toxicity. The ...

Leafy spurge ( L.) is an invasive weed of North America and its perennial nature attributed to underground adventitious buds (UABs) that undergo seasonal cycles of para-, endo-, and ecodormancy. Recommended rates of glyphosate (∼1 kg ha) destroy aboveground shoots but plants still regenerate vegetatively; therefore, it is considered glyphosate-tolerant. However, foliar application of glyphosate...

Background: Soil and plant contamination in copper exposure causes chronic copper poisoning (CCP) in animals following the consumption of plants in these soils. Objectives: The present study was carried out on 10 clinically affected copper poisoned cases (in each season) from autumn 2015 to the end of summer 2016, in four seasons in Kerman province to evaluate the seasonal effects of CCP in she...

In the present study we investigated the seasonal pattern of activity of antioxidant enzymes such as superoxide dismutase (SOD) catalase (CAT) ascorbate peroxidase (APX), guaiacol peroxidase (POD) and syringaldazine peroxidase (SPOD) as well as the total protein concentration in the European mistletoe (Viscum album L. subsp. album). We studied mistletoe leaves that grew on the selected tree spe...

This paper presents a review of the behaviour of radiocesium in plants of forest ecosystems, based on a screening of 375 articles. Particular stress is given to those factors which affect data variability in plants, such as vertical and horizontal patterns of radioactivity in soils due to interception, resuspension, wash-off, litter fall etc. The behaviour of radiocesium in different horizons o...