Treesearch

A serious outbreak of the pine sawfly, Neodiprion pratti pratti (Dyar), now extends over a gross area of more than 14 million acres in Maryland, Virginia, and North Carolina. Since 1955, the approximate extent and severity of infestation have been determined from aerial and ground surveys by the U. S. Forest Service and state personnel. Indications are that the outbreak will continue in 1960.

In the past 40 years, many poorly drained fields and pastures in southern New Jersey have been abandoned; and on some of them even-aged stands of sweetgum have developed. These stands seem to lend themselves well to management because (1) they are accessible, (2) sweetgum is an economically desirable species, and (3) the individual stems are well formed, with good lengths clear of branches.

The 1959 forest tree seed crop is generally light, according to observers. It is better than the 1957 crop, but only in few places is it comparable with last year's production. The better crops were reported in the northwestern Massachusetts-southwestern Vermont area and in the eastern Maine area.

Exactly what happens to young white pine seedlings that have been released from hardwood competition and allowed to grow, subject to browse damage, for a 7-year period? Some indications of the results of such treatment can be seen from recent work on the Massabesic Experimental Forest in Maine.

The past few years have seen increased interest in and use of microbial agents for the control of destructive forest insects. One of the most successful applications of this control method has been the use of the polyhedral virus disease of the European pine sawfly, Neodiprion sertifer (Geoff.). Control of this insect by its specific pathogen has been fully as satisfactory as chemical control, and less expensive.

Scarification of the soil creates seedbeds that are favorable for the establishment of both paper birch and yellow birch. Logging in the summer often has been recommended as a method of obtaining these seedbeds. However, our observations on experimental logging jobs have shown that logging alone does not provide scarification over enough of the area to assure reasonably uniform distribution of birch regeneration.

Hybrid poplars, crosses between European and American Aigeiros poplars, have been grown in Europe for about 200 years. The rapid growth and high productivity of some of these hybrids on sites to which they are adapted has stimulated interest in poplar growing in this country. And demand for these poplars is developing in many parts of the United States.

Experimentation on small watersheds is assuming increasing importance in watershed-management research. Much has been accomplished in developing adequate instrumentation for use in these experiments. Yet many problems still await solution. One difficulty encountered is that small streams are subject to wide variations in flow and that these variations are generally unpredictable; so it is often impossible for personnel to be on the spot at the right time to take samples or to service installations.

Harvesting timber on lands devoted primarily to watershed management may alter, for better or worse, many features of a forested watershed. One such feature is forest humus. The beneficial role of forest humus in watershed management is widely recognized. A protective mantle of humus serves to cushion the impact of rain, to impede surface runoff, to restrict soil freezing, to favor infiltration, and to store certain amounts of rainfall.

On the Dilldown Unit of the Delaware-Lehigh Experimental Forest in Pennsylvania, several planting studies have been made with the aim of finding the most economical and practical methods of converting scrub oak areas to productive high-forest types. These studies have already shown the need for site preparation prior to planting. Seedlings planted on prepared areas grew significantly faster than those in the untreated areas.