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Effects on Ecosystems
Published in Julie Kerr, Introduction to Energy and Climate, 2017
In areas where desertification has already become established, it is important to rehabilitate and restore the lands in order for them to return to their previous conditions. Successful restoration must be done at the local level. Several methods are commonly used, such as the following: Reintroduction of the original, native species that used to live there.Combating erosion through the systematic terracing steep areas so that water does not run down slopes eroding the land’s surface.Establishing seed banks to ensure that species do not become endangered or extinct. Then when climate conditions exist for the plant to survive, seeds can be planted.Enriching the soils with nutrients, making them more fertile and conducive to vegetative growth.Planting additional reserves of trees.
Genetic Resources Conservation: Ex Situ
Published in Yeqiao Wang, Landscape and Land Capacity, 2020
Botanical gardens and arboreta are collections of living plants used for research, study, and education. Arboreta traditionally focus on collections of large trees and shrubs (woody plants) while botanical gardens include research and display collections of both herbaceous (bulbs, biennials, perennials) and woody (trees and shrubs) plants. In actual practice, the boundaries between these two collection types have become less clear during the past century; for instance, many arboreta have expanded their collections to include herbaceous plants but retain their historical names. Both botanical gardens and arboreta are distinguished from public parks and other recreational landscapes by collection policies that emphasize wild-collected plants, by collections organized for scientific and educational purposes, and by extensive documentation; that is, a plant record system that includes information on provenance, nomenclature, and other taxonomic and cultural information of interest to researchers. A herbarium (herbaria, pl.) is a collection of dried, pressed, or preserved plant specimens with associated relevant collection information. Many herbaria are associated with botanical gardens and arboreta; others are associated with universities and other plant science research facilities. Some botanical gardens also maintain or are closely associated with seed banks, facilities where seeds are stored under cold and dry conditions in order to preserve the seed viability for future use.[1] As extinction rates for plant species have increased, these institutions have begun to play important roles in ex situ conservation, or conservation outside the native habitat.
Food Supply
Published in Cameron La Follette , Chris Maser, Sustainability and the Rights of Nature, 2017
Cameron La Follette , Chris Maser
Both of these movements fit well with local seed banks designed to maintain and stimulate use of diverse and traditional crops. Locally owned and controlled, seed banks easily create long-term storage by constant use and re-sowing of seed to protect and maintain viability in storage (which degenerates over time). Seed banks have become essential repositories of genetic diversity owing to the worldwide trend toward monocultures and genetically modified crops (Figure 13.3).
Influence of morphometric and geographic factors on plant community composition of temporary freshwater rockpools in the Maltese Islands
Published in Inland Waters, 2020
Sandro Lanfranco, Andrea Francesca Bellia, Pamela Cuschieri
The sediment layer in the pools functions as a temporary reservoir of water after the surface water would have evaporated and therefore facilitates the persistence of amphibious species toward the end of the wet season. The sediment layer also functions as a seed bank for the pool species. Apart from maximizing the probability of representation of a species in the established vegetation in successive years, the persistent seed bank also provides a buffer against environmental stochasticity that may otherwise have reduced reproductive success. Various unpredictable environmental conditions, including delayed flooding, can lead to a decrease in the number of seeds produced by macrophytes at the end of the wet season (Grillas and Battedou 1998), and a sustained succession of unfavourable years may therefore severely deplete the seed bank. As such, the presence of a perennial seed bank containing seeds that were produced in previous years but did not germinate is adaptive in an unpredictable habitat such as these pools. The depth of the sediment layer was significantly correlated with N2 diversity across all pools, indicating that deeper sediment favours colonization by more functional forms and species relative to shallower sediment. The proximal determinant is longer water retention and accommodation of deeper rhizospheres while the diversity of seeds also increases with sediment volume (Lanfranco et al. 2000). The depth of the sediment was an important selective factor for amphibious plants (Fig. 5). Deeper sediment was colonized by larger plants, including Mentha pulegium, whereas the shallowest sediments were generally colonized by Crassula vaillantii. This result was particularly evident in the MXR landscape, where the pools were generally shallow with a thin layer of sediment, and in which the frequency of C. vaillantii was much higher than in other landscapes. Deeper sediment, more shade, and larger surface areas all promoted higher diversity.