NET PRIMARY PRODUCTIVITY AND PEAT ACCI]MUI,ATION IN SOUTHEASTERN MANITOBA A Thesis Submítted Lo The Faculty of Graduate Studies and Research Universíty of Manitoba in Partíal Fulfillment of the RequiremenËs for Èhe Degree Master of Scíence by Richard Reader May, 1970 @ nicUard Read.er I97L I ofËen say that when you can measuTe what you are speakíng abouË and express iË ín numbers you know something about it. But when you cannot meâsure ít, when you canriot express ít in numbers, your knowledge ís of a meager and unsatisfacËory kind. IË may be Èhe beginníng of knowledge, buË you have scarcely ín your thoughts advanced to the sÈage of science. Lord Kelvin dedicaËed to May 6, 1967 ACKNOI{LEDGB{ENTS The informaËion presented ín Ëhe fo11owíng pages has been accu- mulated with Èhe help of a number of ínterested índivíduals. The author would 1íke to take this opporËuniÈy to Ëhank these contrÍbutors mosË heartily: Mr. T. Carlton, Dr. H. Crum, Mr. C. Hand, Mrs. G. Keleher, Dr. R. Longton, Dr. J. Reíd, and Dr. J. Thomson for the idenËífícatíon and verífícatíon of plant. species, partícularly bryophytes; Mr. M. Bryan and Mr. L. Van Caeseele for aerial photo- graphy; Mr. P. BeckeËt for assistance with the field work; Dr. J. Terasme for radíocarbon daLings; Mr. A. Reimer of the Pinawa Nuclear Research Establishment for meteorological data; the National Research Council of Canada for financial aid in the form of a burs- ary awarded to Ëhe author, and grant Ã-5946 arnrarded to Dr. J. Ster,rart.; and to Dr. E. I{aygood for allowing the work Ëo be carried out in this department. Particular recognition must go to my supervisor, Dr. J. Stewart., who provided me wiËh Èhe opportunity to underËake a problem of pers- onal inËerest. rl- l- ABSTRACT Two functíonal attributes of an ecosysËem, Ttet prímary pro- ducËion and subsequent dry matter accumulation, ürere examined i.n four peatland types (1agg, bog, muskeg, and bog forest) located ín souËheastern Mani-toba . ttaccuDulatíon The simple equaËion = income - losstt ü7as ex- panded in a block diagram to define all poÈential sources of both income and 1oss. Annual t'income" of lj.tter ín Ëhe four vegetatíon zones ranged frorn 489 to 1750 gn./rn.2, which represerì.Ëeð,69-90"/. of. Ëhe calculated net prímary production. "Loss" of dry matËer Ëhrough decomposítion in the followíng year amounted Ëo approximaËe1y one quarter of the 1iËter value. usíng radiocarbon-dated peat cores, an average annual accumulaËion rate of 26-51 gm./m.2/yr. was calculated, suggesËing that less than ten percent of the annual net primary pro- ducËion will remaín as peat. The four vegetation types examíned \^rere considered Ëo repre- sent seral stages ín Ëhe process of secondary succession occurring in the study area. The direcËion of this successíon was hypothe- sized to be Lagg -> Bog -> Muskeg -> Bog Forest. l-v TASLE OF CONTENTS CHAPTER PAGE ABSTRACT iv LIST OF TABLES LIST OF FIGURES xaa LIST OF PROGRAMMES ... xííí I. INTRODUCTION A. Statement of the problem 2 B. LíteraËure review of the concept.s of productíon and accumulation C. Methods employed Ëo calculate planË production and peat accumulat,ion . I II. DEFINIT]ON OF A STTE FOR INVESTIGATION A. Locatíon A4 B. Environmerit.. 76 1. Geology 76 2. Topography ... !7 3. Clímate 18 4. Bíotic influence . 22 C. Vegetation ín areas adjacent to Ëhe peaË1and .... 24 III. REPRESENTATION OF NET PRIMARY PRODUCTtrON AND ACCi]MULATION IN A PEATLÆ{D 25 A. Vegetational patËerns 30 1. PeaËland vegetatíon ... 30 (a) Past vegetaËion in the study area .. 30 v1 TABLE OF CONTENTS (continued) CHAPTER PAGE III. (conËínued) (b) PresenË surface vegetation ... 38 (1) horizonËal distríbutíon of vegeËatíon ín Ëhe study area 38 (2) vertical dístríbution of ve- getaËion in the study area .. 47 B. Determination of Ëhe most productive specíes ín each zorte . 50 C. Biomass, net primary production, and subsequent accumulation of non-vascular vegetation 53 1. Sarnpling scheme 54 2. NeË prímary productíon of ímportant non-vascular species 60 3. Net prÍ-mary production of other speeíes presenË 74 4. Bíomass of non-vascular speci-es 76 5. The contribuËíon of non-vascular species Ëo accumulation income 78 D. Biomass, net primary production, and subsequenÈ accumulation of vascular vegetatíon ... B0 1. Termína1 neÈ primary productíon in vascular specíes . 81 (a) Samplíng scheme for group 'l¿" specíes 81 (b) Sampling scheme for group "b" specíes 83 val- TABLE 0F CONTENTS (contínued) CHÁPTER PAGE III. (contínued) (c) Correctíon factors for litter losË from terminal portíons 85 (d) Terminal production values BB 2. The conÈribution made by leaves produced in prevíous growíng seasons to currenË neË prímary production . 777 3. The conËribution of secondary growËh to aería1 net primary productíon . a2I 4. The total aerial net prímary produe- tion of vascular species 1'25 5. The aería1 component biomass of vascular species 133 6. The contri-bution of aerial vascular com- ponenËs Ëo accumulation íncome 138 7. ProductÍon, biomass, and accumulatíon of sub-surface components of vascular species L47 E. Total net prímary production in each of the four vegetation zones 1"52 F. Total biomass ín each of the four vegeËaËion zones L56 G. Estimating Ëhe amounË of peat accumulated an- nually in each of the four zones ... 160 1. Calculating accumulation "íncome" 161 2. Calculatíng accumulation "loss" t64 3. Calculatíng initial accumulatíon I7I val-a TABLE 0F CONTENTS (contínued) CHAPTER PAGE IV. SI]M},IARY AND CONCLUSIONS 181 BIBLIOGRAPITY . 191 APPENDICES ... 204 A. Species ídentífied in the study area . 205 (a) Vascular species 205 (b) Non-vascular species 207 B. Data processing by digital compuËer ... 209 C. Glossary 2L9 LIST OF TASLES TABLE PAGE I. The annual accumulatíon rate of radiocarbon-dated pear (A)- (c) 34 II. Previous estímates of the accumulaËion raËe of pear (A)- (B) 3s III. Relatíve frequency values of species found ín each of the four vegetation zones 52 ïV. Inportant non-vascular species .. 55 V. Maximum annual net prímary productíon calculated for the important non-vascular species found ín each of Èhe four vegetaËiori zones 72 Vï. Total annual non-vascular net prímary producËion in each of the four vegeÈation zones . 75 VïI. The average biomass total for non-vascular specíes found in each of the four vegeËation zones 77 VIII. The annual contribution nade by non-vascular specíes Èo accumulation 79 IX. Important vascular species 82 X. Maxímum annual values of terminal eomponent net primary producËíon . II4 XI. DensiÈy values for important vascular species found ín Ëhe four vegetation zones (A)-(B) 115 XïI. Values of maximum annual net primary production ex- pressed on an area basis for terminal couponents .... 116 XIII. Current net prímary producËion in Black Spruce leaves produced in previous growing season \20 XIV. Total annual woody increment ín the ímportant vascular specíes studied 423 l_x LIST 0F TABLES (continued) TABLE PAGE XV. The annual radíal incremenË in iuportant vascular species having woody stems L24 XVI. Sumrnary of aerial component neË primary productíon for each of the importanË vascular specíes studied (A)- (D) 127 XVII. Total aerial neË primary production for all vascular specíes occurring in the four vegetation zones (A) - (B) 130 XVIII. Total aerial vascular production ... 732 XIX. Aerial bíomass values of important vascular specíes found in each of the four vegetaËion zones studied .. 135 XX. Total aería1 bÍomass of vascular species ... I37 XXI. Senescence weight loss in leaves of ímpo::Ëant vascular species 147 nII. PosË-senescence weight of leaf and flower-fruit components added annually to the peaÈlandts surface (A)-(D) L43 XXIII. Total annual contributíon of aerial vascular porËíons to Ëhe peaËlandts surface ... 746 XXIV. Total subsurface production in vascular species found in each of the four vegeËation zones 150 XXV. Total net primary production, Íncluding correction for unmeasured losses ¡¡i¡o 155 XXVI. Total plant biomass in each of the four zones ....... 759 XXVII. IniËíal weight of peat-forning material added annually to the peatlandts surface ... 163 ÐWIII. Fraction of origínal weight lost in leaves sub- jected Ëo decomposition for one year (A)-(B) 168 xl- LIST 0F TABLES (continued) TABLE PAGE XXIX. I,Íeight of vascular 1iËter remaining ín the four vegetatíon zones afËer orle year of decomposí- tion (A)-(D) 772 nffi. !üeight of subsurface "litter" remainíng after one year of decomposít.ion L7 4 )o()(I . !üeíght of non-vascular "littertt remaining after one year of decomposition (A)-(D) 775 XXXII. Total weight of litter remaining afËer one year ' of decomposiÈion .:... 1-76 XXXIII. Summary of suecessional changes in net primary producÈion and accumulaËion . 179 LÏST OF FIGURES FIGURE PAGE 1. Locatíon of the peaËland studíed (A)-(D) 15 2. Monthly precípítation recorded at Pínawa, Manitoba 79 3. Mean monËhly Ëemperature recorded aË Pinawa, ManiËoba .. 27 4. The distríbution of dry maËËer resultíng from net prÍmary producËíon ... 27 5. Aerial view of the sÈudy area . 31 6. PeaËland macro-straËigraphy at eight selected poinËs ín the study area . 32 7. The range of specíes along a single line ËransecË . 40 B. The concentric riature of vegetation paËterns 47 9. Vegetatíon in Zone I : Bog Forest (A)-(3) 43 10. Vegetation ín Zone II : Muskeg (A)-(B) 11. Vegetation in Zone III : 3og (A)-(B) 45 72. Vegetation in Zone IV : Lagg (A)-(3) 46 13. VerËi-cal distributíon of hummock specíes on the surface of Ëhe peatland located southwest of Elma 49 14. Bag-Ëypes employed in determining litter correction factors (A)-(B) 86 15. Nylon mesh bags used to determine the inítíal decomposítion rate of leaves in each of Èhe four vegeËation zones (A)-(B) ].67 L6. Nurnerícal values of both net primary production and Ëhe annual accumulation of peaË in each of t-he four vegetaËion zones (A)-(D) 180 xaa LÏST OF PROGRAMMES PROGRAMME PAGE 1.