Table 46. Vigor measurements of sea oats for five sites in Nueces and Kleberg Counties, Texas. 1 





Flowering 

 culms 



Leaves 

 total 



Culm 

 width 



Plant 

 width 



Basal leaves 



Dry weight 

 per culm 



Total weight 



Area 



Leaf 



Width 



Length 



culms 





(no.) 



(no.) 



(mm) 



(cm) 



(no.) 



(mm) 



(mm) 



(g) 



fe) 



Nursery 



4.2 a 



36a 



27 b 



17.8 a 



5.6 b 



12b,c 



106 d 



21 f 



99 a 



Beach 



2.4 b 



21b 



26b 



5.9 b 



4.9 c 



13 a, b 



101 



36 b 



87 a 



Foredune 





















Seashore 



1.1c 



15 c, d, e 



25 b 



2.6 b 



4.2 d, e 



14 a 



107 d 



45 a 



49 b 



North Padre 



1.0 c 



9f 



20 c, d 



1.9 b 



4.1 d, e, f 



12b 



107 d 



35 b, c 



35 b 



Mustang 



1.0 c 



lie, f 



19 d 



1.7 b 



3.9 e, f 



10 a, d 



104 



24 e, f 



24 b 



Interdune 





















Seashore 



1.1 c 



19 b, c 



25 b 



3.7 b 



3.8 f 



12 b 



119 b 



29 c, d, e 



32 b 



North Padre 



1.5 c 



18 b, c, d 



33 a 



6.1b 



7.0 a 



llc,d 



107 d 



28 d, e, f 



42 b 



Mustang 



1.5 c 



21 b 



22 c 



7.6 b 



3.9 e, f 



10 d 



118 b 



23 f 



34 b 



Hind dune 





















Seashore 



1.4 c 



24b 



26b 



4.9 b 



4.3 d 



11 c,d 



120 a 



31 b, c, d 



43 b 



North Padre 



1.5 c 



12 d, e, f 



22 c, d 



4.1 b 



4.8 c 



llc,d 



105 



21 f 



32 b 



Mustang 



1.4 c 



20 b, c 



22 c 



3.4 b 



4.4 d 



10 d 



110 c 



24 e, f 



34 b 



1. Means not sharing a common letter are significantly (P ,) different from all others. 



Sea oats from fertilized nursery and beach plantings were more vigorous than the natural 

 unfertilized dune areas. Apparently, this resulted from the combined effect of fertilization 

 and reduced competition by periodic weeding in the nursery and by the salt-spray 

 environment on the beach. Boyce (1954) concluded that fertilized sea oats were less 

 tolerant to salt spray than unfertilized sea oats in the dune habitat of the North Carolina 

 Banks. No such evidence in fertilized plants was found on Padre Island. No differences in 

 vigor were found among unfertilized foredunes, interdunes, and hind dune plants. If 

 accumulating fresh sand provided extra nutrients to foredune plants, it was not sufficient to 

 significantly increase sea oats vigor. However, compared to the beach planting, sea oats roots 

 in all dune areas were prevented from exploiting their sites because of root competition 

 from other plants growing in these more densely populated plant communities. 



Padre Island data agree with the east coast researchers that sea oats grows most 

 vigorously in sites of large sand accumulations. When stabilization approaches, sea oats' 

 vigor declines and a community with a variety of plant species emerges. Probably the extra 

 vigor is as much a result of reduced competition as from increased nutrients in the fresh 

 sand. 



c. Plant Response to Fertilizer Application. 



(1) In Greenhouse. Most dune stabilization studies show fertilizer to be a valuable aid 

 for increased plant growth which, in turn, allows for increased sand accumulation. To define 

 basic responses of sea oats and bitter panicum to various kinds and levels of fertilization, a 



135 



