PMID- 28311853
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20191120
IS  - 1432-1939 (Electronic)
IS  - 0029-8549 (Linking)
VI  - 65
IP  - 4
DP  - 1985 Mar
TI  - Interactive regulation of grass yield and chemical properties by defoliation, a 
      salivary chemical, and inorganic nutrition.
PG  - 478-486
LID - 10.1007/BF00379660 [doi]
AB  - Clones of 2 C(4) grass species, Sprobolus ioclados and S. pyramidalis, were 
      obtained from more and less heavily grazed grasslands, respectively, in 
      Tanzania's Serengeti National Park. Plants were grown in a factorial experiment 
      to determine the effects of severe defoliation, nutrient limitation, and a 
      salivary chemical (thiamine) on plant growth, nitrogen content, and 
      non-structural carbohydrate content. The experimental design included: (1) 
      species; (2) clipping, with plants either unclipped or clipped weekly to a height 
      of 5 cm; (3) 0.2 ml of distilled water of 0.2 ml of 10 ppb aqueous thiamine 
      sprayed on plants from an atomizer after clipping and identical treatments at the 
      same time to unclipped plants; (4) phosphorus (P) at 0.2 or 1 mM; (5) nitrogen 
      (N) at 3 or 15 mM. Clipping was the major variable affecting plant growth. Total 
      and litter yields were reduced to half and residual plant yield was reduced to 
      30% of the values for unclipped plants. Clipping interacted strongly with other 
      variables since they commonly had minor effects on clipped plants and major 
      effects on unclipped plants. Exceptions to this generalization were generally due 
      to better performance by S. ioclados under clipping. Compared to lower treatment 
      levels, higher treatment levels promoted total yield of unclipped plants by 52% 
      for N, 43% for thiamine, and 33% for P. In general, thiamine had greater effects 
      than P but lesser effects than N. Thiamine promoted yield and modified the 
      chemical balance of plants by promoting carbohydrate (CHO) concentrations and 
      reducing N concentrations. N and P deficiencies promoted CHO accumulation. 
      Clipping promoted the N of leaves and crowns and reduced the N levels in roots. 
      Leaf blade water and N contents were positively correlated with very little 
      scatter. The slope of the line was different for S. ioclados and S. pyramidalis. 
      Leaf blade water and CHO contents were negatively related but there was more 
      scatter and the species could not be distinguished. The species from more heavily 
      grazed grasslands was conspicuously more sensitive to thiamine application. The 
      results indicated that leaf treatment with thiamine, the only likely source of 
      which in natural grasslands is saliva deposited by feeding herbivores, can have 
      major effects on plant yield and metabolic balances at very low application 
      levels. But under defoliation levels as severe as those imposed in this 
      experiment, which reduced above ground plant biomass to a fourth of the level 
      produced by unclipped plants, growth was so strongly limited by defoliation that 
      neither thiamine nor inorganic nutrients affected plant yield residual from 
      clipping. Therefore, whether chemicals such as thiamine that may be introduced 
      onto grass foliage by grazing ungulates and other herbivores will influence the 
      growth of grazed plants will depend upon the grazing intensity associated with 
      the transfer.
FAU - McNaughton, S J
AU  - McNaughton SJ
AD  - Biological Research Laboratories, Syracuse University, 130 College Place, 13210, 
      Syracuse, NY, USA.
LA  - eng
PT  - Journal Article
PL  - Germany
TA  - Oecologia
JT  - Oecologia
JID - 0150372
EDAT- 1985/03/01 00:00
MHDA- 1985/03/01 00:01
CRDT- 2017/03/18 06:00
PHST- 1984/09/08 00:00 [received]
PHST- 2017/03/18 06:00 [entrez]
PHST- 1985/03/01 00:00 [pubmed]
PHST- 1985/03/01 00:01 [medline]
AID - 10.1007/BF00379660 [pii]
AID - 10.1007/BF00379660 [doi]
PST - ppublish
SO  - Oecologia. 1985 Mar;65(4):478-486. doi: 10.1007/BF00379660.