Plant disease resistancePlant disease resistance protects plants from pathogens in two ways: by pre-formed structures and chemicals, and by infection-induced responses of the immune system. Relative to a susceptible plant, disease resistance is the reduction of pathogen growth on or in the plant (and hence a reduction of disease), while the term disease tolerance describes plants that exhibit little disease damage despite substantial pathogen levels.
Potential flowIn fluid dynamics, potential flow (or ideal flow) describes the velocity field as the gradient of a scalar function: the velocity potential. As a result, a potential flow is characterized by an irrotational velocity field, which is a valid approximation for several applications. The irrotationality of a potential flow is due to the curl of the gradient of a scalar always being equal to zero. In the case of an incompressible flow the velocity potential satisfies Laplace's equation, and potential theory is applicable.
Coastal and Estuarine Research FederationThe Coastal and Estuarine Research Federation (CERF) is a private, nonprofit organization that was created in 1971. At that time, the members of two regionally based organizations, the Atlantic Estuarine Research Society (AERS) and the New England Estuarine Research Society (NEERS) recognized the need for a third estuarine organization that would address national (now worldwide) estuarine and coastal issues. Today, CERF is a multidisciplinary federation of members and seven regionally based affiliate societies dedicated to the understanding and wise stewardship of estuaries and coasts worldwide.
Shifting cultivationShifting cultivation is an agricultural system in which plots of land are cultivated temporarily, then abandoned while post-disturbance fallow vegetation is allowed to freely grow while the cultivator moves on to another plot. The period of cultivation is usually terminated when the soil shows signs of exhaustion or, more commonly, when the field is overrun by weeds. The period of time during which the field is cultivated is usually shorter than the period over which the land is allowed to regenerate by lying fallow.
FynbosFynbos (ˈfeɪnbɒs; ˈfɛinbos fine plants) is a small belt of natural shrubland or heathland vegetation located in the Western Cape and Eastern Cape provinces of South Africa. This area is predominantly coastal and mountainous, with a Mediterranean climate and rainy winters. The fynbos ecoregion is within the Mediterranean forests, woodlands, and scrub biome. In fields related to biogeography, fynbos is known for its exceptional degree of biodiversity and endemism, consisting of about 80% (8,500 fynbos) species of the Cape floral kingdom, where nearly 6,000 of them are endemic.
ShrublandShrubland, scrubland, scrub, brush, or bush is a plant community characterized by vegetation dominated by shrubs, often also including grasses, herbs, and geophytes. Shrubland may either occur naturally or be the result of human activity. It may be the mature vegetation type in a particular region and remain stable over time, or a transitional community that occurs temporarily as the result of a disturbance, such as fire. A stable state may be maintained by regular natural disturbance such as fire or browsing.
