IO 



Garden and Forest. 



[January i, 1890. 



precipitation at two stations situated at altitudes of 3,310 feet 

 and 1,250 feet had been in an average of fourteen years 

 sixty-live and fifty-eight inches respectively, while during the 

 year 1882 it reached eighty-nine and eighty-one inches, or 

 about thirty-eight per cent, more than usual. 



Of the soil, which, for the most part, is derived from gran- 

 ites, gneisses, sandstones and clay-slates, eighty-six per cent, 

 were found impermeable. Forest occupies fifty-one per cent. 

 of the whole area, very unevenly distributed, showing, in the 

 various localities, a range of from twenty-two to ninety-one 

 per cent. Of this, sixty-three per cent, is composed of 

 Spruce, the balance of Beech. The forest, to the amount 

 of' sixty-one per cent., was owned by private individuals, in 

 small parcels ; and this part was found more or less in poor 

 condition, owing to mismanagement, with openings or thinly 

 stocked places, especially along steep slopes, with poor roads 

 and suffering from destructive pasturage. The forty-nine per 

 cent, of government and communal forest was in good con- 

 dition. 



Some of the conclusions and observations, in which the 

 report abounds, are as follows : First. The observations at the 

 two stations mentioned before " justify the conclusion that the 

 large percentage of forest (fifty-one per cent.) has caused a 

 considerable increase of rainfall." For, while the average 

 amounts of precipitation for Germany at the same, or nearly 

 the same altitudes, are twenty-seven and a half and thirty- 

 eight inches respectively, the values at these stations, as 

 stated above, are thirty-four per cent, and fifty-seven per cent, 

 higher. 



Second. The retention and retardation of waters, and espe- 

 cially the slower melting of the snow under the forest cover, 

 is acknowledged. In exceptional cases, however, this influ- 

 ence of the forest.it is stated, may become ineffectual, namely, 

 during an unfavorable sequence of periods of heavy precipi- 

 tations, as was the case in the catastrophes of 1882. 



Third. " Entirely beyond dispute, and, hydrologically, of the 

 greatest importance, is the binding of the soil effected by a 

 forest cover, and, in this respect, the forest of the Alb water- 

 shed fulfills its function as a protective cover fully. The satis- 

 factory condition of the water-courses and valley-bottoms 

 and the moderate extent of the damage experienced from the 

 floods in this watershed are due to the small amount of detri- 

 tus. The soil conditions being extremely favorable to the for- 

 mation of detritus and rock chutes, their absence can only be 

 due to the forest cover on the declivities." Where such 

 masses of detritus and waste rock and landslide material are 

 found (on about sixty acres) they can be traced to improper 

 deforestation and pasturage. 



Fourth. An influence of the forest on the flow of springs 

 could not be stated in the region, although it cannot be gen- 

 erally denied. 



Fifth. The employment of flood-reservoirs is discounte- 

 nanced, as disproportionately expensive. 



Sixth. The influence of the Alb forests on the waterflow is 

 stated in summary to the effect that, while the forest could 

 not have prevented such an extreme flood as that of 1882, yet, 

 on the other hand, to the forest is due that the Alb watershed 

 experiences such disasters " only very rarely," and more rarely 

 than adjoining valleys with a smaller proportion of forest area. 



This report, treating the question of forests and floods with- 

 out any preconceived theory to prove, will impress the reader 

 with the fact, which cannot be too strongly insisted upon, that 

 only a careful survey of local conditions can enable us to de- 

 termine how far in any given case a forest cover acts upon 

 hydrologic conditions. 



Not only do rainfall conditions, and the conditions of the 

 forest itself, determine the office of the latter in water distri- 

 bution, but the geological and physical conditions of the soil 

 and its topography, the conditions and comparative length of 

 the water-courses, are also prominent factors of influence. 

 These are elements which enter into the discussion of the 

 character of the "run-off" only ; when the broader question of 

 available water supplies is considered many new elements 

 enter, such as the interception of rainfall by the foliage, the 

 dissipation of water by evaporation, by transpiration, by 

 seepage, and in other ways. 



Department of Agriculture, Washington, D. C. 



B. E. Fernow. 



Correspondence. 



The India Rubber-Tree. 



To the Editor of Garden and Forest : 



Sir. — Referring to the article upon the India Rubber-tree 

 published in your issue of November 13th, it is, perhaps, 

 worth while to call attention to the ease with which that beauti- 



ful tree can be propagated for cuttings. As is well known, it 

 is only necessary to take a piece of a branch and insert it into 

 moist sand and to protect the cutting with a bell-glass to 

 secure a rooted plant ; but it is less well known, perhaps, that 

 the last articulation of the branch is capable of making roots 

 much more quickly and readily than those lower down. Mr. 

 Gamble, inspector of the forests of Madras, in south India, tells 

 me that when they desire, in his district, to make plantations 

 of this valuable tree, workmen always take the end of a 

 branch with a single leaf for the cutting, as experience has 

 shown that this is the way to obtain plants quickly and 

 surely, and I believe that horticulturists would do well 

 to follow this plan always in propagating Ficus elastica. 



This tree, by the way, does not demand a real tropical cli- 

 mate. On the contrary, it flourishes outside the tropics in 

 regions where snow falls sometimes and which experience 

 several degrees of frost. I have seen in the beautiful garden 

 of Hamah, near Algiers, specimens of Ficus elastica, and of its 

 relative, F. Roxburghii, as large as our large forest-trees, cast- 

 ing a shade blacker and thicker than I have ever seen before. 

 Generally, the genus Ficus is hardy and easy to acclimatize. 



Ficus australis succeeds admirably in Algiers, and F. Ben- 

 jamina is used in the same city as a shade tree in the suburb 

 of Mustapha. There is a large specimen of Ficus australis, 

 already old, on the Italian Riviera at Mentone, which, pro- 

 tected on the north by a house, forms a superb mass of dark 

 green foliage ; and at Cadiz there is a handsome avenue of 

 large Fig-trees, with small leaves, not far from the Botanic 

 Garden. These are trees two feet or more in diameter of 

 trunk, with thick spreading heads. There are often severe 

 frosts, however, in all these regions. 



With regard to the fruit of Ficus elastica, I have once seen 

 it on a small plant cultivated in a pot at Bale, so that it appears 

 that this species bears fruit sometimes in a comparatively 

 young state. H. Crist. 



Bale, Switzerland. 



Winter Protection of Plants in Germany. 

 To the Editor of Garden and Forest : 



Sir. — An American is surprised to find so many trees, which 

 are quite tender around Boston, hardy in the latitude of Ber- 

 lin, although the latter city is so many hundred miles further 

 north. Lawson's Cypress and its varieties, Oriental Arbor 

 Vita? and the various forms of Retinospora, for example, 

 seem to be in good condition here, without any protection 

 whatever. So also are the fine specimens of Tree-Box, 

 the foliage of which so often suffers in Massachusetts. The 

 varieties of Ivy show also a marked difference in vigor and 

 hardiness, and are much used as an edging of beds and for low 

 hedging. Probably this difference is caused by the steadiness of 

 the cold here. The sun is so low during the winter months 

 that it has little power, even in the clearest of the short days. 

 As an illustration, a sharp hoar frost on the 10th of Novem- 

 ber was followed by a beautiful clear day, during which the 

 frost remained all day on the northern slopes of the roofs. 

 The moisture of the air is also a noticeable peculiarity. After 

 several days of steady frost, which permitted skating at Berlin 

 and Dresden on the 17th of November, the moisture had so 

 congealed upon the forests that they appeared to have been 

 visited by a considerable fall of snow. 



Undoubtedly the evergreen trees of America suffer from 

 exhaustion caused by the cold, dry winds which sweep through 

 them when the sun runs high, in March. But on the other 

 hand there are many kinds of plants which will not endure 

 this prolonged dampness and freezing of the German climate. 

 Special care is taken for the protection of all such plants. In 

 the gardens of the cities and suburbs, and indeed in the 

 grounds of the nurserymen, the principal material for cover- 

 ing is the boughs of the Norway Spruce. This is regarded as 

 much better than leaves, or anything else that is available. It 

 lies so lightly and is so free from dampness, as compared with 

 leaves, that it is much preferred. And it is laid on with so 

 much neatness and taste as to give the beds the appearance of 

 a plot of living green. The sides of houses, where the Big- 

 nonia and other vines are trained, are laced up with these 

 boughs so neatly that they seem, at a little distance, covered 

 with Evergreen Ivy. 



Our hardy perpetual Roses suffer severely in this climate 

 unless protected, and the boughs prove to be best for this 

 purpose. The bushes are bent and pegged down close to the 

 ground, and are then completely covered with the small 

 branches, usually about two to three feet in length. The sys- 

 tematic trimmings from the forests will, of course, give an 

 unlimited supply of this material, provided the distance of 

 transportation is not too great. 



Berlin. IV. C. Strong. 



