Table 10. Composition of vegetation at "Oak Grove," Permian Tank Area, 

 Padre Island National Seashore, 13 September 1973. l 



Family 



Species 



F 



Percent cover 



Index 2 



Gramineae (Grasses) 



Cynodon dactylon 



92 



9.4 



862 





Eragrostis oxylepis 



82 



4.6 



379 



Cyperaceae (Sedges) 



Cyperus polystachyos 



56 



0.9 



49 





Cyperus esculentus 



23 



0.9 



21 





Cyperus surinamensis 



33 



0.3 



9 



Juncaceae (Rushes) 



Juncus scirpoidea 



17 



0.3 



5 



Loganiaceae 



Polypremum procumbens 



51 



0.7 



37 



Onagraceae 



Oenothera Drummondii 



33 



0.4 



14 



Scrophulariaceae 



Bacopa Monnieri 



52 



1.4 



74 



Compositae 



Erigeron myrionactis 



44 



0.8 



35 



1. Sample consisted of 100 1-meter-diameter hoops systematically thrown in a 300- by 150-foot area. 

 The location is as follows: 



-Oaks 



I 



150 feet 



I 



300 feet 



'25* 



r- N25 W 



North 



2. Importance Index = Product of frequency X percent cover. Maximum - 10,000. 



IV. METHODS: EXPERIMENTAL PLOTS 



The experiments and experimental methods performed during 1969 to 1974 at study 

 plots on Padre Island, and their subsequent monitoring, are discussed in this section and in 

 Section V and Appendix A; individual topics are discussed in detail in the following section. 

 Early in the study, emphasis was on selection of suitable species of dune-building plants and 

 the basic techniques of establishment. Problems encountered during the initial phase were 

 studied and methods tested for circumventing them. In the later project stages, refining of 

 planting techniques continued, with a further study of environmental parameters critical to 

 plant establishment, of modified techniques for planting problem areas (washover passes, 

 fence-built dunes), and a continued monitoring of dune growth and its effect on the 

 surrounding area. 



A summary of the experimental plots with successes and failures is given in Table 1 1 ; the 

 table corresponds with the study site-map in Figures 10 and 11. The maps show only 

 successful sites presently growing. 



45 



