Density guidelines for the management of Quercus suber L. stands in Portugal

Transcription

1 Density guidelines for the management of Quercus suber L. stands in Portugal Teresa Fidalgo Fonseca 1*, LuísaMonteiro 1*, Teresa Enes 1*, AdelaideCerveira 2*,3 1 Forest SciencesandLandscapeArchitecturedepartment 2 Mathematics department *University of Trás-os-Montes e Alto Douro, Portugal 3 INESC TEC, Portugal (Évora, Portugal, 27-30th September 2016) 1

2 Outline Context(cork oak systems) Brief historical background Some figures In the search of optimal density(why?) Hypothesis Analysis Results and discussion(what to do now?) Research findings Implications 2

3 Cork oak systems Autochthonous species in Portugal 737 thousand ha (NFI6, 2010) Differences in structure (woodlands) Montado silvopastoral system Sobreiral forest system Differences in tree architecture 3

4 Differences in structure (woodlands) and in tree architecture North South 4

5 Cork oak systems Social value Aesthetical value Ecological value Mainly driven by Economic value Increase of cork demand for the industry 5

6 Cork export tons Increase in tonnage of cork exports, to 182 thousand tons (APCOR) // PressEstatisticasCortica.pdf 6

7 Howare thecork oak systems? Limited resources Pests and diseases Reduction trend in crown cover Climate change, with undesirable projections Increasing demand Rural depopulation 7

8 Howare thecork oak systems? Limited resources Increasing demand Are theactualdensitiesof thewoodlandsin optimal range? 8

9 (Re)Searching for optimal density Stateof art Flat-rate aid(to support management practices) Silvicultural guidelines(literature) Research Self-thinning law 9

10 (Re)Searching for optimal density flat-rate aid(plantation or sowing) P S /ha P 667 S 226 /ha Density of reference: 450 treesha -1 10

11 Searching for optimal density Silvicultural guidelines(literature) Natividade, J. V., Subericultura. Ministério da Economia. Direção-Geral dos Serviços Florestais e Aquícolas, Lisboa. Montoya, J.M.O, Aproximación al conocimiento del crecimiento y producción de Q. suber L. Cortiça, 557: Montoya, J.M.O, Los Alcornocales. 2ª Ed. Ministerio de Agricultura, Pesca y Alimentación. Serie Manuales Técnicos S.E.A., Madrid. Montero, G., I. Cañellas, Manual de Reforestación del Alcornoque (Quercus suber L.). MAPA-INIA, Spain. Montero, G., I. Cañellas, Selvicultura de los alcornocales en España. Silva Lusitana, 11(1): Lamey, C.A., Le Chêne Liège, Sa Culture et Son Exploitation. Berger-Levraut et C. (Ed), Paris. 11

12 Searching for optimal density Dimension N (trees.ha -1 ) Portugal Spain France C (cm) d (cm) Natividade Montoya Montero&Cañellas Lamey Silvicultural guidelines for cork oak (source: literature review) 12

13 A major impetusfor theoriginand development of forestry has been the search for stand density that provides trees with room to grow and none to waste. B. Zeide Thinning and Growth: A Full Turnaround Journal of Forestry, 2001, 99:

14 Searching for optimal density Are theactualdensitiesof thewoodlandsin optimal range? Can definitively say No Iftheyare not, couldbeincreased? Ifso, howmuch? Research (self-thinning law) 14

15 (Re)Searching for optimal density The allometric relationship assumes that the variation in the number of trees (N, trees ha -1 ) is proportional to the growth in diameter(dg, cm) N = k dg r Self-thinning line ln N = lnk r lndg k and r are allometric constants Stand Density Index (SDI) by Reineke SDI= N (dg/25) -r L.H. Reineke Perfecting a stand-density index for even-aged forest. Journal of Agricultural Research, 1933, 46:

16 (Re)Searching for optimal density Data Portuguese Forest Inventory, NFI plots NFI4 ( ) 546 NFI5 ( ) 1568 Additional data from research plots (RP*) 67 Methods Upper boundary plot selection Data filtering (analytical algorithms) Extreme (N, dg) Self-thinning line *provided by N. Ribeiro (University of Évora) 16

17 (Re)Searching for optimal density Location of the plots by council, for the overall dataset (left) and identification of the location for data set of 36 density-size obs. of the subsample (right). 17

18 (Re)Searching for optimal density Results and Discussion 18

19 SilvoPastoral Silvo-pastoral systems are highly complex Trees, shrubs and herbaceous strata Wild and domestic livestock in same space and time Silviculture includes management techniques that must optimize several productions which may compromise its sustainability and conservation. Is it possible to simultaneously have optimal productions for agro + silvo + livestock? It requires a Multi-criteria decision analysis Adpt. WG 4) Forest management and modeling: silviculture, tree management and planning 19

20 20

21 21

22 Searching for optimal density Are theactualdensitiesof thewoodlandsin optimal range? No Iftheyare not, couldbeincreased? Yes Ifso, howmuch? Depends on the goals (at least least 10-25%) Cork oak systems SilvoAgropastoral Forestry SDI % 45 % SDI % 60 % 22

23 Searching for optimal density Scientistsare human theyare as biasedas anyothergroup. But they do have one great advantage in that science is a self-correcting process. Cyril Ponnamperuma Time for adopting new density guidelines for Quercus suber Acknowledgments To Prof. Carlos Pacheco Marques (UTAD), for his commitment in promoting research on cork oak woodlands. To ICNF for providing the data of the National Forest Inventories To Prof. Nuno Ribeiro (UE) for sharing the data collected in the research plots. 23