Changes in the germinability of seeds of dicotyledonous herbs from anthropogenic and wild habitats during two initial years in a seed bank

Weed Science ◽  
2021 ◽  
pp. 1-40
Author(s):  
Zdenka Martinková ◽  
Alois Honěk ◽  
Marek Brabec

Abstract The germinability of buried seeds changes with time, and the direction and periodicity of these changes differ among plant species. In 116 abundant dicotyledoneous herb species, we investigated the changes in seed germinability that occurred during the 2-year period following burial in the soil. We aimed to establish differences between seeds collected in “anthropogenic” (ruderal, arable land) and “wild” (grassland, forest) habitats. The seeds were buried in a field one month after collection, exhumed at regular intervals and germinated at 25 °C. During the two-year study period, four categories of species-specific patterns of germinability changes were found: seeds demonstrating seasonal dormancy/non-dormancy cycles (31 species), seeds germinating only in the first season after burial (16 species), seeds germinating steadily (38 species) and seeds whose germinability changed gradually, with increasing (7 species) or decreasing (18 species) germinability. The seeds of 6 species did not germinate at all. We found no significant difference in the frequency of these categories between species typical for anthropogenic and wild habitats. The cause for this result may be dramatic human influences (changes of agricultural practices), the pressure of which impedes the development of floras specific for certain habitats, as distinguished by the frequency of species with particular patterns of seed germinability. These frequencies varied among taxa with the growth form, seed mass and flowering phenology of species.

2021 ◽  
Vol 14 ◽  
pp. 194008292110103
Author(s):  
Patrick Jules Atagana ◽  
Eric Moïse Bakwo Fils ◽  
Sevilor Kekeunou

We aimed to assess how bats are affected by habitat transformation by comparing bat assemblages in four habitat types: primary forest, secondary forest, cocoa plantations and human habitations in the Dja Biosphere Reserve of southern Cameroon. Bats were sampled in the four habitat types using mist nets. During 126 nights, a total of 413 bats were captured, belonging to four families, 16 genera and 24 species. Ninety three individuals (17 species) were captured in the primary forest, followed by plantations (105 individuals, 14 species), human habitations (159 individuals, 10 species), and secondary forest (55 individuals, eight species). Megaloglossus woermanni was recorded in all the four habitats, and was the most abundant species (105 individuals). The analysis of bat assemblage between habitat types showed a statistically significant difference in species composition. The distribution of the six most abundant species ( Epomops franqueti, Megaloglossus woermanni, Rousettus aegyptiacus, Dohyrina cyclops, Hipposideros cf. caffer and Hipposideros cf. ruber) was influenced by habitat types. Our results suggest that the decrease in species richness observed in disturbed habitats may be due to habitat perturbations of primary forest habitats. Therefore, it is important to examine the effects of habitat conversion at species level, as responses are often species-specific.


Alpine Botany ◽  
2021 ◽  
Author(s):  
Maria Vorkauf ◽  
Ansgar Kahmen ◽  
Christian Körner ◽  
Erika Hiltbrunner

AbstractAlpine plants complete their seasonal phenological cycle during two to three snow-free months. Under climate change, snowmelt advances and the risk of summer droughts increases. Yet, photoperiodism may prevent alpine plants from benefiting from an earlier start of the growing season. To identify the drivers of flowering phenology in the seven main species of an alpine grassland, we experimentally shifted the snowmelt date through snow manipulations, and excluded precipitation during summer. With “time-to-event” models, we analysed the beginning of main flowering with respect to temperature sums, time after snowmelt, and calendar day (photoperiod). We identified two phenology types: four species tracking snowmelt dates directly or with a certain lag set by temperature sums, including the dominant sedge Carex curvula, Anthoxanthum alpinum Helictotrichon versicolor, and Trifolium alpinum, and three species tracking photoperiod: Geum montanum, Leontodon helveticus and Potentilla aurea. Photoperiodism did not act as daylength threshold but rather modulated the thermal sums at flowering. Hence, photoperiod delayed flowering after earlier snowmelt. The grass A. alpinum was the only one of seven species that clearly responded to drought by earlier and longer flowering. The remarkably high importance of snowmelt dates for both phenology types suggests an earlier onset of flowering in a warmer climate, particularly for non-photoperiod-sensitive species, with an increasing risk for freezing damages and potential disruptions of biotic interactions in the most frequent type of alpine grassland across the Alps. Consequentially, the distinct microclimate and species-specific responses to photoperiod challenge temperature-only based projections of climate warming effects on alpine plant species.


2008 ◽  
Vol 48 (4) ◽  
pp. 397 ◽  
Author(s):  
S. J. Hughes ◽  
R. Snowball ◽  
K. F. M. Reed ◽  
B. Cohen ◽  
K. Gajda ◽  
...  

Australian temperate pasture Genetic Resource Centres (GRCs) co-ordinated a major program to introduce and screen herbaceous forage species. This program aims to expand the environments where such species could reduce recharge and manage discharge for the control of dryland salinity in southern Australia. The sustainability of agriculture, in Australia especially, depends on continued access to new germplasm to enable plant breeders to continue crop and forage improvement. The GRCs supported the selection and identification of promising new legume, grass and herb species as part of a national pasture evaluation program. In total, 671 species and 21 non-species-specific genera were identified as having potential to increase water use profitability of recharge lands and to improve the productivity of saline lands across a diverse range of agricultural environments in southern Australia. Through a series of activities, 201 of these species, representing legumes, herbs and grasses were identified as promising. These were then disseminated for evaluation in a range of environments across southern Australia. The progress of selected species was monitored and germplasm of the most promising 11 species and three leguminous genera was targeted for intensive acquisition and characterisation as the basis for selection and breeding. In addition to the identification and dissemination of promising species of immediate potential, a comprehensive collection of 544 native and exotic, wild and cultivated pasture species was conserved and is now available to service future plant improvement programs.


Genetika ◽  
2015 ◽  
Vol 47 (2) ◽  
pp. 679-694 ◽  
Author(s):  
Uros Zivkovic ◽  
Danijela Miljkovic ◽  
Natasa Barisic-Klisaric ◽  
Aleksej Tarasjev ◽  
Stevan Avramov

We analyzed genetic variability and phenotypic plasticity of flowering pattern and reproductive success in 97 clonal genotypes of Iris variegata originating from contrasting light habitats in Deliblato Sands and expressed under different experimental light conditions. Rhizome segments were taken from each of these clones and transplanted in the experimental garden near the Institute for Biological Research in Belgrade. Significant differences between genotypes were found for two traits (start of flowering, average flowering time). Genotypes originating from open and understory habitats significantly differed for three traits (number of flowers, number of capsules/number of flowers, seed mass/capsule). Significant effect of light treatment were found for three traits (number of capsules/number of flowers, seed mass/capsule, average seed mass). Statistically significant correlations between explored traits were generally similar but also to some extent habitat and treatment specific. Comparing these results with research carried out on congeneric species we noted that there are similar responses for some traits, but also significant differences in some components of flowering and fruiting success.


2020 ◽  
Author(s):  
Karen E Rice ◽  
Rebecca A Montgomery ◽  
Artur Stefanski ◽  
Roy L Rich ◽  
Peter B Reich

Abstract Background and Aims Warmer temperatures and altered precipitation patterns are expected to continue to occur as the climate changes. How these changes will impact the flowering phenology of herbaceous perennials in northern forests is poorly understood but could have consequences for forest functioning and species interactions. Here, we examine the flowering phenology responses of five herbaceous perennials to experimental warming and reduced summer rainfall over 3 years. Methods This study is part of the B4WarmED experiment located at two sites in northern Minnesota, USA. Three levels of warming (ambient, +1.6 °C and +3.1 °C) were crossed with two rainfall manipulations (ambient and 27 % reduced growing season rainfall). Key Results We observed species-specific responses to the experimental treatments. Warming alone advanced flowering for four species. Most notably, the two autumn blooming species showed the strongest advance of flowering to warming. Reduced rainfall alone advanced flowering for one autumn blooming species and delayed flowering for the other, with no significant impact on the three early blooming species. Only one species, Solidago spp., showed an interactive response to warming and rainfall manipulation by advancing in +1.6 °C warming (regardless of rainfall manipulation) but not advancing in the warmest, driest treatment. Species-specific responses led to changes in temporal overlap between species. Most notably, the two autumn blooming species diverged significantly in their flowering timing. In ambient conditions, these two species flowered within the same week. In the warmest, driest treatment, flowering occurred over a month apart. Conclusions Herbaceous species may differ in how they respond to future climate conditions. Changes to phenology may lead to fewer resources for insects or a mismatch between plants and pollinators.


RBRH ◽  
2019 ◽  
Vol 24 ◽  
Author(s):  
Adilson Pinheiro ◽  
Vander Kaufmann ◽  
Gustavo Antonio Piazza ◽  
Claudia Guimarães Camargo Campo

ABSTRACT This work evaluated the response of two scenarios (4.5 and 8.5) of the Eta Model on the quality (sediment - TSS, nitrate - NO3- and phosphate - PO43-) and quantity (flow - Q) of the Concordia Catchment in the Atlantic forest biome. The importance of the work lies in the comparison of both scenarios until 2099, using current agricultural practices (2016). The SWAT model normally used for hydrological purposes has been applied to evaluate water quality from the monitoring programme database (2010-2014). Q showed a non-accentuated, upward trend. Modifications in Q were transmitted to TSS and PO43-. There was no significant difference between the tested scenarios.


2019 ◽  
Vol 11 (13) ◽  
pp. 3617 ◽  
Author(s):  
Megan Grubb ◽  
Christian R. Vogl

Substantial urbanization has allowed individuals to become increasingly spatially and psychologically distanced from the food system and agricultural practices. Food literacy (FL) has been described as a promising approach to reconnect the city with the country and furthermore address public health issues such as obesity and diet-related disease. The present study examined urban gardening through the lens of the FL approach to determine whether a relationship exists between gardening and FL. The research further investigated the relationship between FL and gardener demographics, participation in educational garden events and socialization among gardeners. Data was collected using an online questionnaire targeted to reach community gardeners (n = 181) in Minneapolis and Saint Paul, Minnesota. The research utilized a novel exam and self-perception based measurement tool to assess gardeners’ level of FL. Results indicated a moderately positive relationship between the years of gardening experience and higher individual FL scores. Participants with higher levels of FL were older individuals and more highly educated. There was no significant difference in FL between gardeners who attended educational events and those that had not. The present research presents an initial investigation into the relationship between food literacy and gardening. This research indicates gardening may warrant consideration in holistic approaches to food literacy but further investigation would be valuable.


2016 ◽  
Vol 11 (3) ◽  
pp. 16-19
Author(s):  
Шашкаров ◽  
Leonid Shashkarov ◽  
Кузнецов ◽  
Leonid Kuznetsov

The investigations were carried out in 2014-2015, on a light gray forest heavy loamy soil. The humus content in the arable layer was 5.9%. The mobile phosphorus was 162 and exchangeable potassium was 172 mg per kilogram, respectively, pH of salt extract was 5.6. The total area of the plot was 200 m2, the discount area - 150 m2. Replication - fourfold, placing of plots was successive. Experience scheme: Factor A - preplant soil tillage: 1. Cultivation - 10-12 cm. 2. Milling – 10-12 cm. Factor B – fertilizers: 1. Without fertilizers (control). 2. Fertilizers, aimed to 4.0 tons per hectare (N120P75K90). The following varieties were used as the object of the study: Kornet, Kristal and Nemchinovskaya 56. The norms of fertilizers is calculated by the balance method, based on their removal from the crop and in the soil. The options, treated with a cultivator, were the most clogged. There are no significant difference among tested varieties of Kornet, Nemchinovskaya 56 and Kristal, but Nemchinovskaya 56 was the most clogged - 36 units per square meter, and less weedy was Cornet. When milling , the most clogged was Nemchinovskaya 56 variety - 30 units per square meter. In the way of without fertilization (control), Kristal variety was the most clogged - 21 units per square meter. The weed infestation of winter triticale at the beginning of growing season of Kristal variety was more to 21.3%, Nemchinovskaya 56 variety to 17% and Kristal to 21.6% more, than in milling. At the end of the growing season of winter triticale during cultivation the weeds increased by 71% and 74%. The same pattern was preserved debris perennial weeds early in the growing season 2.4-4.2 units per square meter, at the end of the growing season 4.6-4.7 units per square meter. The most clogged varieties were Nemchinovskaya 56 – 2.8-4.6 units per square meter and Kristal 2.7-4.7 units per square meter.


Social Change ◽  
2001 ◽  
Vol 31 (1-2) ◽  
pp. 75-86 ◽  
Author(s):  
K. V. Raman ◽  
Saroja Raman

Indian agricultural enterprise is one of the largest in terms of human capital and area of operation. It covers approximately 144 mha arable land, more than 60% of the population, and accounts for 40 % of the GDP. Hence its role in overall economic ecological and social development is very critical. Indian agricultural scene is a mix of traditional, low input, subsistence agriculture by the resource-poor farmer and science-based, high-input intensive farming by the rich farmers. Both of them have a share in the impairment of the environment. Because pockets of very high input cultivation are still limited, the pollution due to agricultural waste, excess fertilizers and pesticides are still not as wide-spread and alarming as they are in the west. Soil loss and degradation is the most serious environmental concern generated by the harsh geographical features of the country and by agricultural enterprises, both exacerbated by over-straining animal and human population. Almost 70% of the geographical area is prone to water and wind erosion and other stresses. 5334 million tonnes of soil is eroded annually and 5.3-8.4 million tonnes of the plant nutrients are lost. If this trend continues, one-third of the arable land is likely to be lost. For the fragile and slopy lands, soil conservation measures are being taken up on an extensive scale through water shed approach. These, however, have not been very effective or friendly for over 78% of the small and marginal farmers. Soil Quality, a holistic concept encompassing productivity, environmental quality, and human and animal health, has been developed recently for validating and auditing sustainable agriculture. Several physical, chemical and biological indicators like pH, EC, nutrient status, infiltration rate, soil structure, soil organic carbon etc. have been identified as indicators for measuring soil quality. This approach can be initiated in some places in India to monitor the negative impacts of certain currently prevailing agricultural practices, and facilitate sustainable agriculture through alternate farming protocols. Locale specific, farmer-friendly and conducive packages should be evolved monitored and evaluated in collaboration with the small farmer so that soil resources are conserved or upgraded for future generations.


1985 ◽  
Vol 117 (5) ◽  
pp. 593-598 ◽  
Author(s):  
O.O. Olfert ◽  
M.K. Mukerji ◽  
J.F. Doane

AbstractLosses in yield of spring wheat due to infestations of Sitodiplosis mosellana (Géhin) were determined for 700 000 ha of arable land in northeast Saskatchewan, Canada in 1983. The proportion of kernels infested (y) was a power function of the number of wheat-midge larvae (x) (y = 35.3x0.725). One, 2, 3, and 4 larvae per kernel resulted in a level of infestation of 38, 58, 78, and 96%, respectively. There was no significant difference between infestation levels from fields sampled at the heading stage of crop growth and the estimates of infestation levels for these fields at harvest time. Yield of grain (y) was negatively exponential to an increase in level of infestation (x) (ln y = 5.7−0.017x). Infestations of 30, 60, and 90% reduced yields of spring wheat by 40, 65, and 79%, respectively. The average decrease in crop yield in the study area was about 30%, which resulted in estimated losses in total gross revenue of about $30 million.


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