{"id":111,"date":"2017-04-13T00:10:29","date_gmt":"2017-04-13T00:10:29","guid":{"rendered":"http:\/\/sites.warnercnr.colostate.edu\/larryr\/?page_id=111"},"modified":"2017-04-13T00:10:29","modified_gmt":"2017-04-13T00:10:29","slug":"physiology-feedback","status":"publish","type":"page","link":"https:\/\/sites.warnercnr.colostate.edu\/larryr\/physiology-feedback\/","title":{"rendered":"Physiology Feedback"},"content":{"rendered":"

RS300
\nQuiz
\n09-20-99<\/span><\/p>\n

1.\u00a0\u00a0\u00a0 Dr. Trlica defines plant stress as a external factor applied to the plant, i.e., heat, cold, nutrients, drought, defoliation, etc. (a) true <\/span>(b) false<\/span><\/p>\n

2.\u00a0\u00a0\u00a0 Dr. Trlica defines strain as the plant responses to applied stress, i.e., Ps, growth rate, death rate, seed production, etc (a) true<\/span> (b) false<\/span><\/p>\n

3.\u00a0\u00a0\u00a0 Light is often growth-limiting to grasses on semi-arid rangelands. (a) true (b) false<\/span><\/span><\/p>\n

4.\u00a0\u00a0\u00a0 Over story shading by trees might alter species composition and productivity of under story plants. (a) true<\/span> (b) false [Although a common response to this question is “true,” I’m not so sure. I think it is more a response to water and nitrogen; I’m seeing more and more evidence to back me up.]<\/span><\/p>\n

5.\u00a0\u00a0\u00a0 Under story productivity declines with an increase in conifer cover (albeit not linearly). (a) true<\/span> (b) false<\/span><\/p>\n

6.\u00a0\u00a0\u00a0 Under story productivity declines with an increase in deciduous tree cover. (a) sometimes (b) not always<\/span><\/span><\/p>\n

7.\u00a0\u00a0\u00a0 Tallgrass prairie or bunchgrasses with high leaf area may shade under story photosynthetic tissue. (a) true<\/span>(b) false<\/span><\/p>\n

8.\u00a0\u00a0\u00a0 C3<\/sub> and C4<\/sub> grasses have similar optimal temperatures for photosynthesis. (a) true (b) false<\/span><\/span><\/p>\n

9.\u00a0\u00a0\u00a0 C4<\/sub> grasses can extract more water at higher temperatures than C3<\/sub> grasses. (a) true <\/span>(b) false<\/span><\/p>\n

10.\u00a0\u00a0\u00a0 When nutrients, like nitrogen, are limiting, individual plant growth rates may be depressed, but the system is more stable.(a) true<\/span> (b) false (c) how can that make sense?<\/span><\/p>\n

11.\u00a0\u00a0\u00a0 Respiration is often inversely related to photosysthesis, i.e., as Ps goes down, Rs goes up. (a) true<\/span> (b) false<\/span><\/p>\n

12.\u00a0\u00a0\u00a0 Defoliation (decrease in leaf area) often results in decreased total transpiration. Defoliation often results in decreased total photosynthesis. (a) true-true<\/span>\u00a0 (b) true-false (c) false-true (d) false-false<\/span><\/p>\n

13.\u00a0\u00a0\u00a0 Defoliation (decrease in leaf area) often results in decreased aboveground Rs, but increased below ground Rs. (a) true<\/span> (b) false<\/span><\/p>\n

14.\u00a0\u00a0\u00a0 Defoliation (decrease in leaf area) generally results in decreased seed production. (a) true<\/span> (b) false<\/span><\/p>\n

15.\u00a0\u00a0\u00a0 Plant must maintain a positive carbon balance over time to survive. (a) true <\/span>(b) false<\/span><\/p>\n

16.\u00a0\u00a0\u00a0 When apical dominance in a grass is removed, because the inflorescence is mature, a new rhizome begins growth.(a) true<\/span> (b) false<\/span><\/p>\n

17.\u00a0\u00a0\u00a0 When apical dominance in a grass is removed by biting, a new tiller is initiated. (a) true<\/span> (b) false<\/span><\/p>\n

18.\u00a0\u00a0\u00a0 Biting almost always removes apical dominance in a grass at the 4-leaf stage of growth. (a) true (b) false<\/span><\/span><\/p>\n

19.\u00a0\u00a0\u00a0 Light often limits plant production on arid rangelands. (a) true <\/span>(b) false<\/span><\/p>\n

20.\u00a0\u00a0\u00a0 There is no competition between plants and microbes for nutrients. (a) true (b) false<\/span><\/span><\/p>\n

21.\u00a0\u00a0\u00a0 C3<\/sub> plants usually grow better under warm and dry conditions. (a) true (b) false<\/span><\/span><\/p>\n

22.\u00a0\u00a0\u00a0 Blue grama grass is a C3<\/sub> species. (a) true (b) false<\/span><\/span><\/p>\n

23.\u00a0\u00a0\u00a0 Plants that exhibit a U shaped carbohydrate reserve cycle usually “do better” when grazed during the dormant period. Plants with a “V” shaped reserve cycle are often most vulnerable to defoliation during the period of rapid internode elongation. (a) true-true<\/span> (b) true-false (c) false-true (d) false-false<\/span><\/p>\n

24.\u00a0\u00a0\u00a0 Grazing can be heavier if opportunity for regrowth and environmental conditions are conducive to regrowth following grazing. (a) true<\/span> (b) false<\/span><\/p>\n

25.\u00a0\u00a0\u00a0 Litter buildup in nongrazed areas is beneficial to tillering. (a) true (b) false<\/span><\/span><\/p>\n

26.\u00a0\u00a0\u00a0 Red light near the soil surface can stimulate tillering of grasses.(a) true<\/span> (b) false<\/span><\/p>\n

27.\u00a0\u00a0\u00a0 Trampling of plants and soils by hooves may mechanically injure plants and compact moist soil. (a) true<\/span> (b) false<\/span><\/p>\n

28.\u00a0\u00a0\u00a0 Trampling may be of little significance because wet-dry and freeze-thaw cycles mitigate negatives impact of compaction. (a) true<\/span> (b) false.<\/span><\/p>\n

29.\u00a0\u00a0\u00a0 Grasses typically have hollow, jointed stems with leaves on two sides of the stem. Leaves are narrow with nearly parallel venation and fibrous root system. (a) true (b) false<\/span><\/span><\/span><\/p>\n

30.\u00a0\u00a0\u00a0 The interaction of an individual plant to herbivory depends on (a) phenological stage of development (b) associated species (c) morphogenesis [short<\/span> shoot\/long shoot ratio] (d) environment [opportunity to regrow]<\/span><\/span><\/p>\n

31.\u00a0\u00a0\u00a0 Some grazing avoidance mechanism in grasses might be (a) lignin (b) alkaloids (c) awns (c) cyanogenic compounds<\/span><\/span><\/p>\n

32.\u00a0\u00a0\u00a0 Grazing reduces or stops root growth and recovery may be slow (a) true <\/span>(b) false<\/span><\/p>\n

33.\u00a0\u00a0\u00a0 Little bluestem is known to have a high ratio of long shoots to short shoots and mature shoots break down (oxidize) slowly. How would that contribute to grazing resistance? (a) interferes with access to current, growing phytomass<\/span> (b) Just too tough to eat (c) produces toxins that cause digestive problems.<\/span><\/p>\n

34.\u00a0\u00a0\u00a0 Plants with persistent leaves tend to be high in secondary compounds (a) true <\/span>(b) false<\/span><\/p>\n

35.\u00a0\u00a0\u00a0 Root growth typically occurs at times other than when top growth is active. (a) true<\/span> (b) false<\/span><\/p>\n

36.\u00a0\u00a0\u00a0 Root growth often stops within hours to days of defoliation, but is species specific. (a) true<\/span>(b) false<\/span><\/p>\n

37.\u00a0\u00a0\u00a0 Root exudation may support microbial populations that facilitate availability of nutrients. (a) true<\/span> (b) false<\/span><\/p>\n

38.\u00a0\u00a0\u00a0 Management of leaf area sufficient for photosynthesis is an important tool for vegetation managers; that might be more critical in plants that produce a higher ratio of short to long shoots than vice versa, for example needleandthread grass.(a) true<\/span> (b) false<\/span><\/p>\n

39.\u00a0\u00a0\u00a0 You want to bio-engineer a plant community north of Fort Collins to another plant composition. One of the plants, buffalograss, is found in much greater abundance than desired; western wheatgrass in lower abundance. Should I first develop management strategies to deal with (1) buffalograss or(b) western<\/span> wheatgrass<\/span>?<\/span><\/p>\n

40.\u00a0\u00a0\u00a0 You want to bio-engineer a plant community in northern Utah to another plant composition. One of the plants, big sagebrush, is found in greater abundance than desired; bluebunch wheatgrass and Idaho fescue are found in lower abundance. Should I first develop management strategies to deal with (a) big sagebrush<\/span> or (b) bluebunch wheatgrass and Idaho fescue?<\/span><\/p>\n

\n

RS300
\nQuiz
\n09-24-99<\/span><\/p>\n

1.\u00a0\u00a0\u00a0 You are a range conservationist with a Federal agency. You find yourself in a staff meeting defending the concept of range readiness. You would feel comfortable describing the impact of a grazing regime (time and season of grazing) on a target species, based on our description of organismal response to defoliation. (a) strongly agree (b) agree (c) disagree<\/span><\/p>\n

2.\u00a0\u00a0\u00a0 You would feel comfortable describing the tillering response of a growing cool-season grass following removal of the apical meristem (growing point). For example, you could defend an argument regarding survivability of that tiller or the survivability of the plant. (a) strongly agree (b) agree (c) disagree<\/span><\/p>\n

3.\u00a0\u00a0\u00a0 You have been invited to give a presentation to the Fort Collins Garden Club. You are well into your presentation, when someone asks if the wildrye (a cool-season\u00a0 bunchgrass) in their pasture will set seed if their horse eats some of the green leaves in late April. You assure the person the grass will set seed. (a) strongly agree (b) agree (c) disagree<\/span><\/p>\n

4.\u00a0\u00a0\u00a0 Response of an individual plant to herbivory under natural conditions depends on frequency, intensity and timing of defoliation in relation to phenological development, associated plants, individual species’ characteristics (morphogenesis) and opportunity to compensate for herbivory (environment). Dr Woodmansee wants you to elaborate on these ideas in his basic ecology class. You volunteer to help him lead the discussion. (a) You are confident you understand the facts. (b) You are confident you understand the application. (c) no response<\/span><\/p>\n

5.\u00a0\u00a0\u00a0 In temperate zones like Colorado, 25 days opportunity to regrow following defoliation in late spring is probably adequate, even if more than 50% of the leaf was removed. (a) almost certainly (b) probably not<\/span><\/span><\/p>\n

6.\u00a0\u00a0\u00a0 An understanding of the mechanisms that allow a plant, monocot or dicot, to withstand the effects of defoliation is fundamental to the professional rangeland manager. (a) yes<\/span> (b) no<\/span><\/p>\n

7.\u00a0\u00a0\u00a0 You can think of scenarios where removal of a high proportion of the phytomass (e.g., 60% of leaves) of perennial grasses would not change the stability of the system. (a) For example, if plants were allowed opportunity to compensate for that herbivory. (b) For example, plants had continuous and adequate supply of nutrients and water. <\/span>(c) For example, as long as tissue was removed by elk, not domestic sheep.<\/span><\/p>\n

8.\u00a0\u00a0\u00a0 The ideas presented in the section apply only to defoliation of plants by domestic herbivores. (a) yes (b) no<\/span><\/span><\/p>\n

9.\u00a0\u00a0\u00a0 Shrubs may be more sensitive to herbivory than the herbaceous layer and require greater periods of compensation. This is especially true of cold desert shrubs; maybe less true of montane or sub-humid shrubs. Many shrubs invest heavily in secondary compounds as a mechanism to resist herbivory. (a) true<\/span> (b) false<\/span><\/p>\n

10.\u00a0 Tall wheatgrass is known to have a high ratio of long shoots to short shoots and mature shoots break down (oxidize) slowly. That means animals never remove growing points during herbivory. (a) true (b) false<\/span><\/span><\/p>\n

11.\u00a0 Short shoots (graminoids) are represented by phytomers with elongated internodes. (a) true (b) false<\/span><\/span><\/p>\n

12.\u00a0 Plants that exhibit a “U-shaped” carbohydrate depletion\/replenishment cycle are vulnerable to herbivory during the active growing period, i.e., they recover more slowly than if defoliated during a dormant period. (a) true<\/span> (b) false<\/span><\/p>\n

13.\u00a0 Plants with a “V” shaped CHO depletion\/replenishment cycle are often most vulnerable to defoliation at the 4-leaf stage of development. (a) true (b) false<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span><\/span><\/b>\u00a0\u00a0 Depends on how frequently tillers are bitten. Young tissue is photosynthetically very active and efficient. Once apical meristem is removed,<\/span> plants need an environment that allows adequate time to compensate for tissue removal, i.e., need to regain 25 to 30 % of tissue that would\u00a0have been grown had the tiller not been grazed.<\/span><\/span><\/p>\n

14.\u00a0 Root growth typically occurs much earlier in the growing season than top growth. (a) true<\/span> (b) false<\/span><\/p>\n

15.\u00a0 The stem is the basic unit of the grass tiller. (a) true (b) false<\/span><\/span><\/p>\n

16.\u00a0 Sedges\/Carex spp typically have hollow, jointed stems with leaves on two sides of the stem. Leaves are narrow with nearly parallel venation and fibrous root system. (a) true (b) false<\/span><\/span><\/p>\n

17.\u00a0 A grazed tiller always dies during that growing season. (a) true(b) false<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 No, parts of leaf could have been removed, but not apical meristam. In that case tiller could live more than one year – seldom more than 2<\/span><\/span><\/p>\n

18.\u00a0 Grazed grass plants die each season and are replaced with plants that generate (colonize) from new seedlings each year. (a) true (b) false<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span><\/span><\/b>\u00a0\u00a0\u00a0 A common misconception is that plants die each year and regenerate from seed. Simply not so.<\/span><\/span><\/p>\n

19.\u00a0 When a short shoot of a dicot is removed vis-a-vis herbivory, that shoot dies back to the nearest meristimatic tissue. (a) true<\/span> (b) false<\/span><\/p>\n

20.\u00a0 C4 compared to C3 grasses generally have more fiber, the fiber is more lignified, lower nitrogen content (especially at maturity), carbohydrates in form of starch vs sugars, have greater tolerance for high temperatures (optimal photosynthesis occurs a<\/span>t higher temperatures), etc. (a) true (b) true<\/span><\/span><\/p>\n

\n

RS300
\nQuiz
\n10-01-99<\/span><\/p>\n

1.\u00a0\u00a0\u00a0\u00a0 Start with an unfenced parcel of land. Your planning team decides the best way to meet a goal related to some value is to graze each area (equal size in this\u00a0 instance) for 13 days and rest each area 42 days. How many pastures would fit that scenario, on average?<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 P = (R + DG)\/DG P = (42 +13)\/13<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Answer is 4 to 5 pastures<\/span><\/span><\/p>\n

2.\u00a0\u00a0\u00a0 Given another scenario. The area is already fenced into 16 similar sized pasture which are contiguous. If animals are in each pasture 10 days, what is the rest period? If animals are in each pasture 4 days, what is the rest period?<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 R = DG(P – 1) R = 10 (10 – 1) = 90<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 R = 4 ( 10 – 1) = 36<\/span><\/span><\/p>\n

3.\u00a0\u00a0\u00a0 Given another scenario. An area is already fenced into 10 similar sized pastures which are contiguous. I want to set a rest period of 40 days on the first rotation, 60 days on the second rotation and infinity on the 3rd<\/sup> rotation, how long would animals stay in each pasture on each rotation?<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 DG = R\/(P – 1) DG = 40\/(10 – 1) = 4 to 5 days<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 DG= 60\/(10 – 1) = 6 to 7 days<\/span><\/span><\/p>\n","protected":false},"excerpt":{"rendered":"

RS300 Quiz 09-20-99 1.\u00a0\u00a0\u00a0 Dr. Trlica defines plant stress as a external factor applied to the plant, i.e., heat, cold, nutrients, drought, defoliation, etc. (a) true (b) false 2.\u00a0\u00a0\u00a0 Dr. Trlica defines strain as the plant responses to applied stress,… <\/p>\n","protected":false},"author":117,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-111","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/sites.warnercnr.colostate.edu\/larryr\/wp-json\/wp\/v2\/pages\/111","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sites.warnercnr.colostate.edu\/larryr\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/sites.warnercnr.colostate.edu\/larryr\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/sites.warnercnr.colostate.edu\/larryr\/wp-json\/wp\/v2\/users\/117"}],"replies":[{"embeddable":true,"href":"https:\/\/sites.warnercnr.colostate.edu\/larryr\/wp-json\/wp\/v2\/comments?post=111"}],"version-history":[{"count":1,"href":"https:\/\/sites.warnercnr.colostate.edu\/larryr\/wp-json\/wp\/v2\/pages\/111\/revisions"}],"predecessor-version":[{"id":112,"href":"https:\/\/sites.warnercnr.colostate.edu\/larryr\/wp-json\/wp\/v2\/pages\/111\/revisions\/112"}],"wp:attachment":[{"href":"https:\/\/sites.warnercnr.colostate.edu\/larryr\/wp-json\/wp\/v2\/media?parent=111"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}