How do trees respond to species mixing in experimental compared to observational studies?

For decades, ecologists have investigated the effects of tree species diversity on tree productivity at different scales and with different approaches ranging from observational to experimental study designs. Using data from five European national forest inventories (16,773 plots), six tree species diversity experiments (584 plots), and six networks of comparative plots (169 plots), we tested whether tree species growth responses to species mixing are consistent and therefore transferrable between those different research approaches. Our results confirm the general positive effect of tree species mixing on species growth (16% on average) but we found no consistency in species-specific responses to mixing between any of the three approaches, even after restricting comparisons to only those plots that shared similar mixtures compositions and forest types. These findings highlight the necessity to consider results from different research approaches when selecting species mixtures that should maximize positive forest biodiversity and functioning relationships.

Flowering and fruiting phenology of tree species in mount papandayan nature reserve, west java, indonesia.

Mount Papandayan Nature Reserve (MPNR) is an area highly rich in biodiversity, however deforestation has left a vast area urgently in need of reforestation. When reforestation is designed to restore some level of biodiversity, it is imperative that native tree species are used for planting. This research aimed to provide information on the flowering and fruiting phenology of native trees. Such information can be useful to plan seed collection and mass seedling production in the nursery. The observations were conducted each month during August 2009-July 2010 by recording flowering and fruiting trees along two survey track passing through the middle of the mixed forest of MPNR. Data gathered were used to construct a simple phenology calendar. During the study, there were 155 trees of 43 species found flowering or fruiting along the survey track. The peak time of flowering and fruiting was in July (13 species flowering and 19 species fruiting), while the lowest level was in October (1 species flowering and 3 species fruiting). According to the phenology calendar constructed, March to July were considered to be the appropriate time to collect seeds of native trees in Mount Papandayan.