Abstract:
Pinus patula and Pinus tecunumanii play an important role in the forestry sector
in the tropics and subtropics and, in recent decades, members of the International Tree
Breeding and Conservation Program (Camcore) at North Carolina State University have
established large, multi-site provenance trials for these pine species. The data collected in
these trials provide valuable information about species and provenance choice for plantation
establishment in many regions with different climates. Since climate is changing rapidly, it
may become increasingly difficult to choose the right species and provenance to plant. In this
study, growth performance of plantings in Colombia, Brazil and South Africa was correlated
to the degree of climatic dissimilarity between planting sites. Results are used to assess the
suitability of seed material under a changing climate for four P. patula provenances and six
P. tecunumanii provenances. For each provenance, climate dissimilarities based on
standardized Euclidean distances were calculated and statistically related to growth
performances. We evaluated the two methods of quantifying climate dissimilarity with
extensive field data based on the goodness of fit and statistical significance of the climate
distance relation to differences in height growth. The best method was then used as a
predictor of a provenance change in height growth. The provenance-specific models were used to predict provenance performance under different climate change scenarios. The
developed provenance-specific models were able to significantly relate climate similarity to
different growth performances for five out of six P. tecunumanii provenances. For P. patula
provenances, we did not find any correlation. Results point towards the importance of the
identification of sites with stable climates where high yields are achievable. In such sites,
fast-growing P. tecunumanii provenances with a high but narrow growth optimum can be
planted. At sites with climate change of uncertain direction and magnitude, the choice of
P. patula provenances, with greater tolerance towards different temperature and
precipitation regimes, is recommended. Our results indicate that the analysis of provenance
trial data with climate similarity models helps us to (1) maintain plantation productivity in a
rapidly changing environment; and (2) improve our understanding of tree species’
adaptation to a changing climate.
