Dominant Mer’a Bitkilerinin Biomas ve Kimyasal Kompozisyonlarının Büyüme Dönemindeki Değişimi I. Biomas ile Kök/Sap, Sap, Yaprak, Çiçek Oranlar›n›n De¤iflimi

Bu çal›flma 1994 y›l›nda Atatürk Üniversitesi Kampüsünde otlatmaya kapal› alandan seçilen otlak ayr›¤›, havl› brom, koyun yuma¤›, adi parlakot, adi sorguçotu, melez yonca ve top keki¤i üzerinde yürütülmüfltür. Araflt›rmada bitkilerde geliflme fenolojisi, boy, toprakalt› ve üstü biomas›, kök/sap, sap, yaprak ve çiçek oranlar› incelenmifltir. Bitkilerde boy uzamas› bafllang›çta yavafl, sonra h›zl› ve çiçeklenmeyle birlikte tekrar yavafl bir seyir takip etmifltir. Biomas de¤erleri de boydaki de¤iflime benzer bir seyir izlemifltir. Kök/sap oranlar› bafllang›çta yüksek olurken, özellikle sapa kalkmadan sonra azalm›flt›r. Yaprak oran› bafllang›çta tüm bitkilerde yüksek iken, sapa kalkmadan sonra azalm›fl ve sap oran› artm›flt›r.

Variation in Biomass and Chemical Composition of Dominant Rangeland Plants During the Growing Season I. Changes in Biomass, Root/Shoot Ratio, Stem, Leaf, Flower Ratios

This study was conducted to determine annual variations in the below- and above-ground biomass, root/stem, stem, leaf and flower ratios of crested wheatgrass, subalpine brome, sheep fescue, junegrass, needlegrass, hybrid alfalfa and cat thyme. The specimens were collected during the growing season of 1994 from protected rangelands in Erzurum area. Plant height increased slowly at the onset of growth, accelerated in the middle of a growth stage and levelled off after the blossom stage. The accumulation of below- and above-ground biomass was similar to the trend of growth in plant height. Root/stem rations were highest at the beginning of the growth stage, after which they steadily decreased especially after stem elongation. While the leaf ratio was highest at the beginning of the growth stage in all the plants, it steadily decreased after the stem elongation stage.