Present Status of Sasa Resource in Japan and Examination of Suitable Period for Its Grazing Use

By WAICHI AGATA

Faculty of Agriculture, Kyushu University

Sasa (Bamboo grass or dwarf bamboo) ing use of Sasa resource. species are representative native wild grass in Japan together with Miscanthus sinensis and Zoysia japonica, all of which are main Species and distribution species constituting semi-natural grasslands. Most of Sasa species are distributed end According to Flora of Japan12> 11 species demically in the Far East. In Japan there are reported as endemic species belonging to are many species of Sasa and they cover an genus Sasa. Among them, Sasa kurilensis, S . area of about 50% of mountainous regions, palmcita, S. nipponica and S. borealis are main which occupy about 70% (25 million ha) of species distributed widely in Japan. Their the whole land area of Japan. Judging from distribution and ecological characteristics are the status that the mountainous area used shown in Table 1, which indicates that the for grazing is only 500,000 ha at present, it genus Sasa is mainly distributed from cool is estimated that Sasa resource to be utilized temperate zone to subarctic zone. Generally, for livestock feed is still very abundant in the distribution area of genus Sasa shows Japan. Moreover, Sasa is evergreen plant and an increasing trend with higher latitude, for is able to be used even in winter season. From example, the genus Sasa accounts for an area that viewpoint, it is considered that the Sasa of about 90% of the national forest land in plant in Japan is one of the most promising Hokkaido14>. According to Suzukil G> and resources as roughage for livestock. Usui1S>, S. nipponica and S. borealis are main In this report the author attempts to give ly distributed in the Pacific Sea side, whereas a review on species, distribution, feeding S. kurilensis and S. palmata in the Japan Sea value and biomass of Sasa plant in Japan, and side in the northern part (Kanto district and also to examine the suitable period for graz- northward) of the country. Such an ecolo-

Table 1. Ecological distribution and characteristics of main Sasa species in Japan

Distribution Ecological characteristics

Plant height Winter bud Depth of Life span Species Climatic zone Main region (m) position on rhizome of culm culm (year) . . Cool temperate Japan Sea side in northern S asa kunlensis and subarctic region(Kanto and northward) 1.0- 3.0 Upper part Shallow 7- 10 l t Cool temperate Japan Sea side in northern Sasa pa mci and SuzukilG> indicated that the eco logical distribution of species is influenced There is not many study as to feeding value mainly by snow-depth, and is most closely re of Sasa. Table 2 shows the result of leaf lated to the relation between snow-depth and analysis on Sasa nipponica by Ohara11>, to height of winter buds formed on culms (life gether with that of orchardgrass (Dactylis form), among many ecological characteris glomerata) for reference. Contents of crude tics. protein, crude fat and soluble non-nitrogen Sasci is floor (shade-enduring) plant in de compounds in Sasa leaf are almost similar to ciduous broad-leaved and coniferous forests. those of orchardgrass. However, Sasa leaf But if these forests are once destroyed by contains more crude ash and less crude fiber cutting, fire etc., it grows rapidly and main than those of orchardgrass. Also Obara11> tains pure community for long time, although reported that content of vitamin C in S. it is in a serial stage of plant succession. nipponica is very high. Moreover, in grazing Especially, widespread, pure and dense com experiment on S. pcilmata grassland with cow, munities of Sasa are formed at slopes of Mitamurail reported 0.66-0.88 kg/day of daily volcanoes in the northem part of Honshu. gains. These results suggest that the feeding Apart from the genus Sasci mentioned value of Sasa leaf is not inferior to that of above, there is Arundinaria pygmaea, dwarf orchardgrass. bamboo, in Japan (Table 1). A. pygmaea is distributed widely in nilly areas of warm tem perature zone, southward from the Tokai Biomass of Sasa community district. It's distribution is within a range of 0-800 m and is replaced by genus Sasa To utilize Sasa plants as livestock feed, it over 800 m in elevation. As A. pygmaea is necessary to make clear the biomass (total forms a sun plant community, it's growth is plant substance) in communities of Sasa spe not well in the forest floor or in the forest cies. The biomass of Sasa community in margin. In areas lower than 300 m in eleva Japan differs with species and environmental tion, it is semi-deciduous in winter, but it conditions. Table 3 shows the summarized becomes deciduous at elevations higher than result on above-ground biomass of Sasa spe 500 m. A. pygmaea has been used for rough cies reported upto date in Japan. All of these age from old time in a similar way as genus values were obtained from high density com Sasa. Particularly, at Aso and Kujyu high- munities. As shown in Table 3, the above-

Table 2. Comparison of feed in g value between Sasa nipponica and orchard grass (Dactylis oromelata:)

Species Crude protein Crude fat Soluble non-nitrogen Crude fiber Crude ash (%) (% ) compounds (%) (% ) (%) Sasa nipponica 11.34 4.36 39.83 28.90 15.57 (Winter season) Dactylis g1·omelatci 12.10 3.88 40.29 33.98 9.70 (Headind stage)

% based on dry matter 108 JARQ Vol. 14, No. 2, 1980 ground biomass differs remarkably with spe cies. For instance, the biomass of S. kurilensis Tomi community shows 10 times that of S. nippon ::::1 1100 e ica. As there is no great differences in leaf • amount among Scisa species, it is evident 1000 that the biomass differences are mainly caused by different culm amounts. As can be esti mated from Table 1, the culm amounts of Sasci species are closely related to longevity of culms and plant heightH>. Incidentall y, in the case of Sasa plant, only leaf blade is used as the feed for livestock. Consequently, it can be said that there are no large differences in leaf biomass as feed among species. As shown in Table 3, leaf biomass in dense Sasa communities under 500 favourable environmental conditions is in the •100 range of 230- 573 g/m2• However, there are two types of seasonal variations of leaf 300 biomass, namely, one with leaf biomass vary ol_._, ·~ M:1y Jun. Jul. Aug. St:1). reported that S. lcuril However, as compared to the differences in ensis community and S. niklwensis commu biomass observed among species, differences nity showed about the same annual net

Table 3. Biomass of leaf, culm and' total above g1·ound, and LAI of communities of some Sasa species in Japan

Species Sampling site (prefecture) Researcher Leaf weight Culm weight Above ground LAI (g/m2) (g/m2) biomass(g/m2) (m2/m2)

Sasa ku1-ilensis Mt. Waisuhorun(Hokkaido) Oshima1° 465 7,430 7,895 5.2 Sasci kii1-ilensis Kamisaibara {Okayama) Saijoh et a1.m 572 8,000 8,572 6.4 Sasci va,l11wta Kawatabi(Miyagi) Naito et aJ.9> 229 541 770 4.5 Sasa oseana Ozegahara ( Fukushima) Oshimam 250 1,158 1,408 4.1 Sasa nikkoensis Mt. Yatsugatake( Nagano) Oshima141 318 1,574 1,892 5.0 Sasa nivponica Mt. Kirigam!ne( Nagano) Oshima141 256 490 746 4.5 Sasa nim>onicci Mt. Asama(Nagano) Agata et al. 11 345 347 692 6.2 Sasa nip1)onica Shibahara ( Fukushima) Akiyama et al}1 229 477 706 5.0 Sasci nim,onica Mt. Sefuri (Fukuoka) Agata et al. 21 298 812 1,110 6.4 Sasa borealis Chidanemachi (Hyogo) Nishida et a1.101 573 1,749 2,322 5.7 A rundinaria Kujyu (Oita) Iwaki et alY 230 228 458 4.0 v11u1naea A nmdina1'i.<1, Kujyu (Oita) Numata et at.5> 230 479 709 5.2 7>ygmaea 109

production in spite of that the above ground years. To keep biomas to be constant every biomass of the former was about 4 times that year, it is important to establish a rntional of the latter. This result gives an evidence method of grazing use based on annual that there is no difference in annual net pro growth pattern and cutting response of duction of Sasa communities of different biomass. The author carried out the follow species under favourable environmental con ing study3> with Sasci nipponica, which is ditions. Such annual net production of Sasa superior in palatability and intake among community is not so low as compared with Scisa species. · that of other native grass communities, such as Miscanthus sinensisO>, M. saccharifioruso>, 1) Annucil growth pattern Arundinella hirta/'» and Zoysia japonica13> etc. Monthly changes of dry matter of each Although the Scisa plant is not advantageous organ obtained from the dense community of for plant matter production owing to its low Sctsa nipponica are shown in Fig. 1. Above photosynthetic abilityH> and productive struc ground biomass increased rapidly from spring ture of drooping leaf type:.i,141 its annual net to summer, reachLng a maximum in late production is almost similar to other native August, and then decreased gradually towards grasses, depending on the fact that it is an the next spring. When the above-ground evet·green plant and continues production biomass was divided into the fresh one throughout the year. (newly produced in the year) and the over Thus, the differences of biomass observed wintered one, it was found that new culms among $asa species can be understood. How sprouted in May produced the fresh biomass, ever, biomass of Sasa community varys with which exceeded the overwintered biomass in environmental conditions, such as solar radia June, and then most of the biomass was domi tion, air temperature etc. Therefore, the nated by the fresh one in August. author investigated the relation between an Contrastingly, the under-ground biomass nual solar radiation (x) at the floor of vari showed the trends of decrease from mid ous kinds of forest and above ground biomass spring to summer and of increase towards (y) in Sasa nipponica community, and ob late autumn. The decrease until summer and tained a close relation as follows1 >: the increase after summer correspond to the rapid increase of fresh biomass and the sup y=6.9x + 53.4 (t·=0.943;H:·) ply of assimilate from the fresh biomass, re Furthet·more a high positive relation between spectively. Thus, the total of above and under elevation (x) which is closely t·elated to air ground biomass is kept almost constant temperatm·e and leaf biomass (y) in Sasa throughout the year. Such a seasonal change nipponicci community was also obtained as fol has been recognized in other Sasa species1,H>, lows1>: indicating that annual growth pattern of Sasa community is not so different with species. y= - 0.19x+578.3 ( r= -0.989·»·») Moreover, it was made clear that numbers of winter buds on 1·hizomes and of new rhizomes also showed seasonal variations:!> Examination of suitable period for and time of their formation differs each other grazing use of Sasa g1·assland owing to their differential response to day length:IJ. For grazing use of Sasa grassland for suc cessive years, it is desirable to maintain 2) Biomass resvonse to cutting above-ground biomass constant for many Influence of time and frequency of cutting years. But, above-ground biomass in Sasci on biomass was studied with Sasa ni1111onica3l. community tends to decrease year after year The results are shown in Fig. 2 and Fig. 3. when it is utilized by grazing for successive As shown in Fig. 2, monthly cutting resulted 110 JARQ Vol. 14, No. 2, 1980

Sampling in Sc1,.1966 A,,t. 1967 mm CJ Above ground parl 400 - !z:3 Under ground par I "1: 7 300 "o e 1400 6 e :-- 1200 5 200] s ,._ 4- 0 :3 IOOO . :5 ~ 800 J 100 J e 600 2 z" g 400 I 0 200 0

Mny Jun. Jul. Aug. Aug. Oct. No\•, De<.~. Jan. Feb. M:ir. Apr. cul 11 ~ J I 29 J 4 S 11 I ~3 28 Culling datcin 1966 ill 1967

Fig. 2. Influence of cutting time on biomass (g/m2) of the whole plant, above· and under-ground parts, number of culms (No./m2), and leaf area index in Scisa nipponica com munity

LAI Regarding the remarkable reduction in ·100 8 above-ground biomass caused by August cut ting, it was confirmed that the decreased ::'300 (, { under-ground part and retarded winter bud ~ s 2SOO~ formation in autumn were responsible for if!> . i1 'i; 3200 •I 21)003 Fig. 3 shows the effect of cutting frequency. 'o The biomass above and under-ground, num l: J 1.soo! E ~ ber of culms and LAI were remarkably de i'.100 ~oooa creased in parallel to the increase of cutting soo frequency. 0 0 0 3 S) Suitable gmzing period

Fig. 3. Influence of cutting frequency on bio From the results shown above, it can be mass (g/m2) of the whole plant, above concluded that the suitable period for grazing and under-ground parts, number of which enables utilization of biomass year after culms (No/m2), and leaf area index in Sa.sa nip7>onica community on Sept. 26, year is from November to April, because re 1968. (Cutting treatment was carried serve substances and winter buds are suffi out during summer growing season in ciently prepared in rhizomes by this periods, 1967) and also the amount of above-ground biomass in above ground biomass less than 60% of taken away by grazing is less than that in the non-cutting treatment (control). Summer other months. However, as the biomass of cutting, in general, decreased the biomass Scisa community tended to decrease by grazing more seriously than autumn-spring cutting, as well as cutting, the most desirable method especially cutting in August induced drnstic of utilization is to adopt a rotational grazing decrease. or no grazing at an inte1·val of 2 or 3 years. The under ground biomass, number of On the other hand, to convert Sasa grass culms and LAI were affected by the cutting land to other uses, such as tame grassland treatment similarly to the above-ground and afforestation, summer season, especially, biomass. Such results were also observed with August is the most suitable period to do it, Sasa palmata20J, S. borealis 1s> and A rundina1·ict because Sasa community is destructed most pygmaeat7>. effectively. 111

Nat. Ag1·. Exv. Sta., 42, 1-203 (1948) [In Ref e1·ences Japanese]. 12) Ohwi, J.: Flora of Japan. Shibundo, Tokyo, 1) Agata, W. et al.: Biomass of Sasa nipponica 89-98 (1965) [In Japanese). community at Mt. Asama. Bull. G1·assl. Ecol. 13) Okubo, T. et al. : Ecological efficiencies of Res. G'r., 16, 32-38 (1977) [In Japanese]. energy conversion in pasture. 2. Seasonal 2) Agata, W. et al. : Biomass of Sasa nipponica changes of matter production and light community at Mt. Sefri. Bull. Gmssl. Ecol. utilization in Zoysia-type grassland under Res. Gr., 17, 15- 20 (1978) [In Japanese]. one-year protection from grazing. J Jap. 3) Agata, W. et al.: Ecological characteristics Grassl. Sci., 23, 30-42 (1977) [In Japanese and dry matter production of some native with English summary). grasses in Japan. 1. Annual growth pattern 14) Oshima, Y.: Ecological studies of Sasa of Sasa nipvonica community. J. Jap G1·assl. communitis. I. Productive sti·ucture of some Sci., 25, 103- 109 (1979) [In Japanese with of the Sasa communities in Japan. Bot. Mag. English summary) ; 2. Effects of time and Tokyo, 74, 199-210 (1961) ; II. Seasonal frequency of cutting on dry matter produc variations of productive structure and an tion in Sasa nivponica community. ibid., 25, nual net production in Sasa communities. 110-116 (1979) [In Japanese with English ibid., 74, 280- 290 (1961); III. Photosynthesis summa1·y) ; 3. Effects of day length on for and respiration of Sasa ku1·ilensis. ibid., 74, mation of winter bud and new rhizome in 349- 356 (1961). Sasa nivvonica. ibid., 25, 117- 120 (1979) 15) Saijoh, Y. et al.: Ecological studies for [In Japanese with English summary]. vegetation management on the stand domi 4) Akiyama, T. et al.: Ecological efficiencies nated by Sasa. I. P1·oductive structure and of energy conversion in pasture. 3. D1·y the amount of litter. Res. B.ull. Fae. Gifii matter production in Sasa nipponica com Univ., 40, 251- 259 (1977). munity. J. Jav. Grassl. Sci., 23, 43- 51 (1977) 16) Suzuki, S.: Ecology of the Bambusaceous [In Japanese with English summary). genera Sasa and Sasamo1-pha in the Kanto 5) Iwaki, H. et al. : Standing crop of Pleio and Tohoku districts of Japan, with special blasti,s community in Kujyu. Bull. G'rassl. reference to their geographical distribution. Ecol. Res. Gr., 8, 8- 11 (1966) (In Japanese). Ecol. Rev., 15, 131-147 (1961). 6) Midorikawa, Y. et al.: Root p1·oduction in 17) Ueda, K. et al.: Physiological and ecological semi-natural grassland community dominated studies on the Sasa (Pleioblastus pubescens by Misccinthus sinensis in the Kawatabi area. NAKAI). Bull. Kyoto Univ. Forests, 27, 112- JIBP Synthesi.s, 13, 114- 122 (1975). 129 (1958) [In Japanese with English 7) Mitamura, K.: Studies on highland live summary]. stock farming in Japan, with special l'efer 18) U sui, H.: Phytosociological revision of the ence to Hokkaido. Aninial Hasband1y, 1, dominant species of Sasa-type undergrowth 209- 214 (1947) [In Japanese). ( Silvicultural application of the 1·esearches 8) Morimoto, H.: Forage Science. Tokyo, on Japanese forest vegetation). Biill. Coll. Yokendo, 593- 641 (1975) [In Japanese). Ag1·. Utsunomiya Univ., 11, 1-35 (1961) [In 9) Naito, T. et al. : Some effects of fire on the Japanese with English summary]. regeneration of Sasa pal1nata. Ja7>. J. Ecol., 19) Yuruki, T.: Ecological studies of Suzutake 18, 79- 82 (1968) [In Japanese with English (Sasa borealis). Biill. Kyushu Univ. Fo1·ests, Summary]. 50, 83- 122 (1977) [In Japanese with English 10) Nishida, K. et al.: On the productive stl'Uc summary]. tu1·e in some species of Sasa. Bull. G1·assl. 20) Yoshida, S.: The !'elation between difference Ecol. Res. G1-., 13, 50- 66 (1972) [In Japa of cutting time and the plant succession of nese]. Sasa-land. Bull. Inst. Ag1·. Res. Tohoku 11) Ohara, H.: Studies on feeding value of Univ., 2, 187- 218 (1950) [In Japanese with Sasci species in Hokkaido. Rev. Hokkciido English summary].