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Abstract: The physical and biological characteristics of five stations in and near a tidal creek were studied for 18 months. Tidal creeks and tidal rivers are differentiated and defined. Diel fluctuations of dissolved oxygen and temperature were greatest and tidal-induced salinity oscillations the least at the headwaters of the creek. Small salinity oscillations promoted a high overall diversity of fishes at the head-waters of the creek, even though few fish species maintained permanent populations there. Juvenile fishes were abundant in the summer and fall. Extreme temperature and low dissolved oxygen levels prompted a migration of fishes from these areas in late summer. Permanent fish populations were found at the mouth of the creek and in an adjacent tidal river.

AbstractA technique is presented that requires no direct measurement of gallery length to estimate the total gallery length. Required to obtain the estimate are: (1) an appropriate model for time of year, sample period, and host, (2) tree diameter at breast height, (3) length of infested bole, (4) total tree height, and (5) inner bark thickness. The technique is accurate, less time consuming, and less expensive than direct estimation techniques.

AbstractNine sampling units for estimating southern pine beetle population within a tree are compared according to unit size, strata size, and number and type of sampling allocation. As a measure of performance of different sampling schemes or different unit sizes the ratio of the variances of the estimate is used, i.e. relative efficiency.Relative efficiency decreases as unit size increases, where equal surface area is sampled. Unequal stratification, which allocates smaller area to the upper and lower strata, results in higher relative efficiencies than equal stratification. Thus, unequal stratification is recommended. Samples should be allocated to these strata according to the optimal sampling ratios.