Grasses and grasslands are of increasing interest to conservationists, biologists, and gardeners. There are more than 300 species of native California grasses and they are found in almost every ...climate—from cool, wet forests to hot, dry deserts. Native grasses are also important to land restoration as they improve soil quality, increase water infiltration, and recycle nutrients. Their deep roots can tap soil water, which allows them to stay green year-round and to act as fire buffers around residences. Native grasses also provide vital habitat for many species of insects, birds, reptiles, and mammals. Despite their importance, grasslands remain one of the most underprotected of California's vegetation types, and native grasslands have undergone the greatest percentage loss of any habitat type in the state. Grasses are also among the most difficult plants to identify. Organized alphabetically, Field Guide to Grasses of California covers common native and naturalized grasses and, to help identify them, also features over 180 color illustrations.
Aim
Little is known about the distribution of grasses throughout Australia. Using endemism as a basis for understanding biogeographical distributions, we hypothesised that contemporary species ...richness would be the result of environmental factors and dynamic ecological interactions spanning more than 25 Ma.
Location
Australia.
Taxon
Grasses.
Methods
We mapped the distribution of all Australian grass species and modelled climatic and landscape correlates according to photosynthetic type (C3 or C4), endemism, age in Australia, phylogenetic lineage and traits linked to dominance, using height as a proxy. Age classes comprised ‘Ancient’ (Gondwanan), and three others related to migration during the Sunda‐Sahul Interchange (SSI): Early, Mid or Recent. In some analyses, ‘Ancient’, ‘Early SSI’ and ‘Mid SSI’ were combined into ‘Pre‐Recent SSI’.
Results
Overall, species richness of C4 grasses increased with warmer mean annual temperatures, while richness of C3 grasses was higher in cooler areas. Recent SSI species had strong associations with summer rains and were dominant in the continent's northeast, with Pre‐Recent SSI species concentrated in the southeast, a pattern largely reflecting photosynthetic type (C4 and C3 respectively). Endemic and shared species distribution patterns support a migration sequence in which most C3 Pooideae and Panicoideae genera arrived in Australia before the Pliocene aridifications, followed by C4 Chloridoideae as aridification increased, with C4 Andropogoneae immigrating most recently across Lake Carpentaria's open habitats in the later Pleistocene. Recent SSI shared species were significantly taller than Pre‐Recent SSI endemic grasses.
Main Conclusions
The few grasses present in Australia before the Pliocene grew in cooler areas. The influx of taller Recent SSI grasses contributed to dramatic environmental changes—including creation of the northern savannas—with repercussions for resident taxa. Contemporary methods of fuel management could be promoting invasion by grass, thereby jeopardising the conditions suited to ancient taxa and threatening the region's evolutionary history.
Form, development and function of grass stomata Nunes, Tiago D. G.; Zhang, Dan; Raissig, Michael T.
The Plant journal : for cell and molecular biology,
February 2020, Letnik:
101, Številka:
4
Journal Article
Recenzirano
Odprti dostop
Summary
Stomata are cellular breathing pores on leaves that open and close to absorb photosynthetic carbon dioxide and to restrict water loss through transpiration, respectively. Grasses (Poaceae) ...form morphologically innovative stomata, which consist of two dumbbell‐shaped guard cells flanked by two lateral subsidiary cells (SCs). This ‘graminoid’ morphology is associated with faster stomatal movements leading to more water‐efficient gas exchange in changing environments. Here, we offer a genetic and mechanistic perspective on the unique graminoid form of grass stomata and the developmental innovations during stomatal cell lineage initiation, recruitment of SCs and stomatal morphogenesis. Furthermore, the functional consequences of the four‐celled, graminoid stomatal morphology are summarized. We compile the identified players relevant for stomatal opening and closing in grasses, and discuss possible mechanisms leading to cell‐type‐specific regulation of osmotic potential and turgor. In conclusion, we propose that the investigation of functionally superior grass stomata might reveal routes to improve water‐stress resilience of agriculturally relevant plants in a changing climate.
Significance Statement
A key challenge for plants is to efficiently use water, particularly when growing in a hot and dry climate. Stomata – cellular breathing pores on leaves that mediate gas exchange between plant and atmosphere – have a pivotal role in controlling water‐use efficiency. Stomata can adjust their pore size to balance carbon dioxide uptake with water vapour loss. Interestingly, grasses like the three most important food crops rice, maize and wheat have improved stomata that can regulate water use more efficiently by opening and closing faster than other plants. Rapid stomatal movements are linked to the grass stomata's unique morphology consisting of dumbbell‐shaped guard cells and lateral subsidiary or helper cells. Recently, work on domesticated and wild grass species has started to reveal some of the secrets regarding how grass stomata form and function more efficiently.
Millets were a part of human diet as well as fodder in the past and was helpful in prevention of many diseases especially lifestyle diseases. Because of the dependence on wheat and rice as major ...source of food and the rise in use of junk food, millets were neglected from routine diet. The rise in incidence of non-communicable diseases, across the globe has helped generate an awareness to include nutri-cereals in the daily food to address the contemporary of lifestyle. Information pertaining to millets, especially on Indian millets, has been collected from various resources, books, research papers and e-platforms for the researches on millets. Nine types of millets are widely used across India. Millets have been the cornerstone of Indian cuisine since centuries and there is much scope for its revival in the present era.
Buckwheat is a short-season, multi-nutrient crop commonly known as “
Kuttu
” in India and used to make flour “
Kuttu ka Atta
” and utilized to prepare a variety of dishes. Buckwheat has small, ...triangular seeds, frequently used as substitutes for cereals like wheat and rice and commonly cultivated at high altitudes, particularly >1000 masl, where other cereal crops are not as readily available. It is relatively easy to grow, adapts well to various soil types, requires little water, and thrives in moderately fertile soil, which makes it an ideal crop for farmers where water sis scarece and soil is not fertile. Buckwheat is a gluten-free grain that contains carbohydrates, phenolics, protein, dietary fiber, omega-3 and omega-6 fatty acids, and vitamins. Furthermore, it is also said to be beneficial in a number of diseases such as Zn, Cu, Fe, P, Mn, and Mg. Buckwheat has also been used to treat a number of diseases like high blood pressure, digestive troubles, skin problems, and so on. Coordinated efforts are required to improve production and encourage consumption of buckwheat.
Semiarid grasslands of the Nebraska Sandhills provide critical ecosystem services and are an important forage resource for the local cattle industry. Over the past decades, warming and ...climate-related extremes have affected grassland production worldwide, which promotes the initiation of numerous grassland monitoring projects. Despite this, production trends for plant functional groups in the Sandhills regions in recent years have remained unknown. In this study, we analyzed plant biomass production of the Sandhills grasslands with a dataset collected over 15 yr from 2007 to 2021. Ungrazed total biomass and biomass of individual plant functional groups were assessed in grazing exclosures twice a year, in mid-June (for early season) and mid-August (for late season). This first paper reports our findings on total biomass and compositional changes of the three major plant functional groups, as well as trends in precipitation and temperature during the study period. A significant increasing trend (P < 0.05) was observed in temperature over time during the early season (April to mid-June), with a weak monotonic increasing trend (P = 0.07) during the full season (April to mid-August), whereas no significant pattern was reported for precipitation during the study, although it displayed complex within- and across-season patterns. The proportion of C3-grass biomass in total biomass increased (P < 0.05), while the proportion of C4-grass biomass decreased (P < 0.01). We did not observe any significant trends for forbs; however, the drought of 2012 resulted in up to a fivefold increase in the proportion of forb biomass the following year. These findings enhance our understanding of current patterns in grassland production and contribute to regional evidence on the response of plant functional groups to variability and extremes in intra-annual weather variables, which can improve our capability to perform adaptive grazing management in a similar semiarid grassland ecosystem.
Human-induced increases in nitrogen (N) deposition are common across many terrestrial ecosystems worldwide. Greater N availability not only reduces biological diversity, but also affects the ...biogeochemical coupling of carbon (C) and N cycles in soil ecosystems. Soils are the largest active terrestrial C pool and N deposition effects on soil C sequestration or release could have global importance. Here, we show that 27 years of chronic N additions to prairie grasslands increased C sequestration in mineral soils and that a potential mechanism responsible for this C accrual was an N-induced increase in root mass. Greater soil C sequestration followed a dramatic shift in plant community composition from native-species-rich C
4
grasslands to naturalized-species-rich C
3
grasslands, which, despite lower soil C gains per unit of N added, still acted as soil C sinks. Since both high plant diversity and elevated N deposition may increase soil C sequestration, but N deposition also decreases plant diversity, more research is needed to address the long-term implications for soil C storage of these two factors. Finally, because exotic C
3
grasses often come to dominate N-enriched grasslands, it is important to determine if such N-dependent soil C sequestration occurs across C
3
grasslands in other regions worldwide.
The Cape south coast presents some of the world's most significant early modern human sites preserving evidence for complex human behaviour during the Middle Stone Age (MSA), and it is centrally ...located in the megadiverse Greater Cape Floristic Region. The extinct Palaeo-Agulhas Plain (PAP) once abutted this region, forming an important habitat for the subsistence strategies of past hunter-gatherers during the MSA. Here, we use phytoliths — amorphous silica particles that formed in cells of plants — extracted from archaeological deposits of two sites at Pinnacle Point (PP; cave 13B PP13B and site 5–6 PP5-6) to investigate the interactions between environments and hunter-gatherer foraging strategies along the Cape south coast during Marine Isotope Stage (MIS) 6 to MIS 3. To do this, we developed an analytical approach built on a modern plant and soil reference collection for using phytoliths from archaeological deposits for palaeoenvironmental reconstructions. In the latter phases of MIS 6, phytoliths indicate shrubby vegetation, possibly limestone fynbos, which might have occurred in inland landscapes, and this was the area preferred for plant foraging practices by the inhabitants of PP13B. During MIS 4, phytoliths at PP5-6 indicate the presence thicket and riparian vegetation on the rocky cliffs and the exposed PAP, along with some type of fynbos vegetation above the actual coastal cliffs. During interglacials MIS 5(c-e) and MIS 3 when the PAP was less exposed, the phytolith record points towards a mosaic of habitats with fynbos and thicket/forest, but also a constant presence of vegetation with high grass content dominated by a mix of both C3 and C4 species. Our data suggests a continuous inland regional mosaic of habitats with fynbos, thicket/forest and grassy vegetation that persisted during the glacial-interglacial periods. The changes observed in the phytolith record might be indicative of changes in plant foraging preferences along with slight vegetation movements in accordance with climate changes and sea level fluctuations.
•Phytoliths can infer vegetation types distribution along the Cape south coast.•Phytoliths were considered a merged product of human behaviour and local vegetation.•Thicket and riparian were the most preferred vegetation types foraged for firewood.•Regional mosaic habitats were present at Pinnacle Point over time.•The Cape south coast experienced rapid biome shifts during the Pleistocene.
We investigated biochar-induced drought tolerance in Leptocohloa fusca (Kallar grass) by exploring the plant defense system at physiological level. L. fusca plants were exposed to drought stress ...(100%, 70%, and 30% field capacity), and biochar (BC), as an organic soil amendment was applied in two concentrations (15 and 30 mg kgsup.−1 soil) to induce drought tolerance. Our results demonstrated that drought restricted the growth of L. fusca by inhibiting shoot and root (fresh and dry) weight, total chlorophyll content and photosynthetic rate. Under drought stress, the uptake of essential nutrients was also limited due to lower water supply, which ultimately affected metabolites including amino and organic acids, and soluble sugars. In addition, drought stress induced oxidative stress, which is evidenced by the higher production of reactive oxygen species (ROS) including hydrogen peroxide (Hsub.2 Osub.2 ), superoxide ion (Osub.2 sup.− ), hydroxyl ion (OHsup.− ), and malondialdehyde (MDA). The current study revealed that stress-induced oxidative injury is not a linear path, since the excessive production of lipid peroxidation led to the accumulation of methylglyoxal (MG), a member of reactive carbonyl species (RCS), which ultimately caused cell injury. As a consequence of oxidative-stress induction, the ascorbate–glutathione (AsA–GSH) pathway, followed by a series of reactions, was activated by the plants to reduce ROS-induced oxidative damage. Furthermore, biochar considerably improved plant growth and development by mediating metabolites and soil physio-chemical status.
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