תפריט נגישות
ניגודיות עדינהניגודיות גבוהה
מונוכרום
הדגשת קישורים
חסימת אנימציה
פונט קריא
סגור
איפוס הגדרות נגישות
להורדת מודול נגישות חינם תפריט נגישותניגודיות עדינהניגודיות גבוההמונוכרוםהדגשת קישוריםחסימת אנימציהפונט קריאסגוראיפוס הגדרות נגישותלהורדת מודול נגישות חינםNelmy Narvaez1, Miguel Mellado Wolfgang Pittroff
Seasonal variations in condensed tannins (CT) content and bioreactivity were determined in eleven dominant California chaparral species. CT are important plant secondary compounds limiting the effectiveness of small ruminants to consume these plants as a fire fuel reduction approach. Plant samples were collected monthly for one year. Leaves and stems were analyzed grouped by season for soluble and insoluble CT. Bioreactivity of condensed tannins (TBR) was determined for leaf samples. The tanniniferous shrub species sampled were ranked, in terms of soluble CT (SCT) concentration, in the following order: A. fasciculatum < H. arbutifolia < Q. durata < A. stanfordiana < C. cuneatus < Q. wislizenii < A. glandulosa < Q. douglasii < A. canescens. Seasonal variations of SCT followed a different pattern in each plant species. Compared to leaves, stems of all species had the highest and lowest SCT and insoluble CT concentrations, respectively. TBR in leaves differed among species (P < 0.05). Tannins from C. cuneatus (Sierra) and H. arbutifolia showed lowest bioreactivity, whereas tannins from Quercus spp. and A. fasciculatum had the highest. According to TBR, the ranking order of the shrubs was: C. cuneatus (Sierra) < H. arbutifolia < A. stanfordiana < A. glandulosa < C. cuneatus (Hopland) < A. canescens < A. fasciculatum < Q. durata < Q. wislizenii < Q. douglasii. In disagreement with previous studies in this ecoregion, we found that key California chaparral species contain high levels of tannins and bioreactivity, constraining the effectiveness of small ruminants in fire fuel reduction without appropriate supplementation regimes.
Abstract no. 2337-1
Nelmy Narvaez1, Miguel Mellado Wolfgang Pittroff
Seasonal variations in condensed tannins (CT) content and bioreactivity were determined in eleven dominant California chaparral species. CT are important plant secondary compounds limiting the effectiveness of small ruminants to consume these plants as a fire fuel reduction approach. Plant samples were collected monthly for one year. Leaves and stems were analyzed grouped by season for soluble and insoluble CT. Bioreactivity of condensed tannins (TBR) was determined for leaf samples. The tanniniferous shrub species sampled were ranked, in terms of soluble CT (SCT) concentration, in the following order: A. fasciculatum < H. arbutifolia < Q. durata < A. stanfordiana < C. cuneatus < Q. wislizenii < A. glandulosa < Q. douglasii < A. canescens. Seasonal variations of SCT followed a different pattern in each plant species. Compared to leaves, stems of all species had the highest and lowest SCT and insoluble CT concentrations, respectively. TBR in leaves differed among species (P < 0.05). Tannins from C. cuneatus (Sierra) and H. arbutifolia showed lowest bioreactivity, whereas tannins from Quercus spp. and A. fasciculatum had the highest. According to TBR, the ranking order of the shrubs was: C. cuneatus (Sierra) < H. arbutifolia < A. stanfordiana < A. glandulosa < C. cuneatus (Hopland) < A. canescens < A. fasciculatum < Q. durata < Q. wislizenii < Q. douglasii. In disagreement with previous studies in this ecoregion, we found that key California chaparral species contain high levels of tannins and bioreactivity, constraining the effectiveness of small ruminants in fire fuel reduction without appropriate supplementation regimes.
Abstract no. 2337-1
