東華大學圖書館 |

語系: 繁體中文

說明(常見問題)

回圖書館首頁

手機版館藏查詢

登入

回首頁

切換: 標籤 | MARC模式 | ISBD

Factors Affecting the Strength and S...

Jones, Emily.

FindBook

Google Book

Amazon

博客來

Factors Affecting the Strength and Sensitivity of an Herbivore-Induced Seaweed Defense.

紀錄類型:	書目-電子資源 : Monograph/item
正題名/作者:	Factors Affecting the Strength and Sensitivity of an Herbivore-Induced Seaweed Defense./
作者:	Jones, Emily.
出版者:	Ann Arbor : ProQuest Dissertations & Theses, : 2016,
面頁冊數:	110 p.
附註:	Source: Dissertation Abstracts International, Volume: 78-04(E), Section: B.
Contained By:	Dissertation Abstracts International78-04B(E).
標題:	Ecology. -
電子資源:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=10164164
ISBN:	9781369187502

Factors Affecting the Strength and Sensitivity of an Herbivore-Induced Seaweed Defense.
Jones, Emily.

Factors Affecting the Strength and Sensitivity of an Herbivore-Induced Seaweed Defense. - Ann Arbor : ProQuest Dissertations & Theses, 2016 - 110 p.

Source: Dissertation Abstracts International, Volume: 78-04(E), Section: B.

Thesis (Ph.D.)--San Diego State University, 2016.

Herbivores play key roles in structuring communities, influencing both the species composition and individual traits of primary producers. In marine systems, much of what we know about induced trait changes in seaweeds and seagrasses is based on pairwise interactions between conspecific and heterospecific herbivores. However, multiple herbivores often co-occur in communities, feeding on primary producers simultaneously. If herbivores act antagonistically or synergistically, whether through direct interactions or induced seaweed traits, net herbivore effects in an assemblage may differ from individual species. We currently have a limited understanding of the role of induced defenses in more complex herbivore communities, and I attempt to increase this knowledge in Chapters 1 and 2.

ISBN: 9781369187502Subjects--Topical Terms:

516476
Ecology.

Factors Affecting the Strength and Sensitivity of an Herbivore-Induced Seaweed Defense.
LDR:06226nmm a2200337 4500 001 2120822
005 20170724102534.5
008 180830s2016 ||||||||||||||||| ||eng d
020 $a 9781369187502
035 $a (MiAaPQ)AAI10164164
035 $a AAI10164164
040 $a MiAaPQ $c MiAaPQ
100 1 $a Jones, Emily. $3 1977840
245 1 0 $a Factors Affecting the Strength and Sensitivity of an Herbivore-Induced Seaweed Defense.
260 1 $a Ann Arbor : $b ProQuest Dissertations & Theses, $c 2016
300 $a 110 p.
500 $a Source: Dissertation Abstracts International, Volume: 78-04(E), Section: B.
500 $a Adviser: Jeremy Long.
502 $a Thesis (Ph.D.)--San Diego State University, 2016.
520 $a Herbivores play key roles in structuring communities, influencing both the species composition and individual traits of primary producers. In marine systems, much of what we know about induced trait changes in seaweeds and seagrasses is based on pairwise interactions between conspecific and heterospecific herbivores. However, multiple herbivores often co-occur in communities, feeding on primary producers simultaneously. If herbivores act antagonistically or synergistically, whether through direct interactions or induced seaweed traits, net herbivore effects in an assemblage may differ from individual species. We currently have a limited understanding of the role of induced defenses in more complex herbivore communities, and I attempt to increase this knowledge in Chapters 1 and 2.
520 $a In addition to focusing on individual species, most studies in marine systems have tested for induced defenses under ambient or high herbivore abundances. However, herbivore abundances can vary greatly across sites and between populations. Investigating how this variation affects the strength of inducible seaweed defenses at different spatial scales will increase our knowledge on where these defenses are most important. I address these ideas in Chapter 3.
520 $a In Chapter 1, I investigated how herbivore composition affects the strength of an inducible defense in the brown seaweed Silvetia compressa. Although terrestrial herbivore species can elicit different pathways that suppress or enhance inducible plant defenses, marine studies comparing the strength of induced defenses between herbivores interacting sequentially versus simultaneously are lacking. In addition, we know little about whether herbivore assemblage responses differ from individual species in any system. To test these ideas, I used laboratory mesocosm experiments to examine whether 1) herbivore elicitation of and response to Silvetia's induced defense were species-specific and 2) whether elicitation and response by an herbivore assemblage differed from the individual species. I found that although an herbivore assemblage can induce defenses in Silvetia, the strength of elicitation by an assemblage was weaker compared to Silvetia grazed by the strongest inducer (Tegula funebralis ) only. Furthermore, individual herbivores had varied responses to Tegula grazing, avoiding, preferring, or not responding to grazed tissues. The net effect of these individual preferences appeared to reduce avoidance of Tegula-grazed Silvetia by the herbivore assemblage. Overall, these results suggest that strong pairwise interactions between herbivores may be weaker when seaweeds are grazed by multiple herbivores.
520 $a In Chapter 2, I compared the relative strength of Silvetia's induced defense between two herbivores with different grazing modes. A variety of studies have quantified differences in herbivore-induced defenses by measuring induced compounds or indirectly comparing differences between grazed and non-grazed tissues. However, herbivore feeding preferences depend on food choice, and direct comparisons of grazed tissues may differ from those predicted by indirect comparisons. Using lab mesocosm experiments, I tested whether palatability differed between seaweeds grazed by snails and seaweeds grazed by isopods. I found that snail-grazed tissues were less palatable than isopod-grazed tissues, suggesting that snails induce stronger defenses than isopods. These differences were not due to grazing rate during the elicitation phase or a lack of response to isopod grazing, but may be due to chemical differences between snail and isopod-grazed tissues. These results suggest that in communities where herbivores elicit defenses of different strength, interspecific interactions between herbivores may be asymmetric, depending on which seaweed phenotypes have been induced. (Abstract shortened by ProQuest.).
520 $a In Chapter 3, I investigated how variation in the abundance of a single herbivore species influenced the strength and sensitivity of Silvetia induced defenses in different populations. Geographic comparisons of herbivore-induced seaweed defenses have typically tested whether the strength of induced defenses differs between populations. However, seaweed populations may also vary in sensitivity to grazing, such that one population induces defenses at lower levels of grazing than another population. Little research in marine or terrestrial systems has incorporated tests of sensitivity into studies of induced defenses. Filling this gap is necessary to understand the importance of these defenses in populations with different abiotic or biotic conditions. Through a series of common garden experiments, I determined that geographic differences at low levels of grazing were not due to environmental conditions, herbivore source, or constitutive palatability. Instead, this variation in sensitivity between populations may be due to long-term differences in environmental histories, such as grazing pressure, that have caused local adaptation or left legacy effects from exposure to local conditions. Overall, our results indicate that geographically separated Silvetia populations can greatly vary in sensitivity to grazing by a common herbivore species.
590 $a School code: 0220.
650 4 $a Ecology. $3 516476
650 4 $a Biological oceanography. $3 2122748
690 $a 0329
690 $a 0416
710 2 $a San Diego State University. $b Ecology. $3 3168305
773 0 $t Dissertation Abstracts International $g 78-04B(E).
790 $a 0220
791 $a Ph.D.
792 $a 2016
793 $a English
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=10164164