1. Tree growth–survival relationships link two demographic processes that dictate the com-position, structure and functioning of forest ecosystems. While these relationships have been shown to vary intra-specifically, it remains unclear how this reflects environmental variation and disturbance. We examined the influence of a 700-m elevation gradient and an Mw = 6.7 earthquake in 1994 on intra-specific variability in growth–survival relationships. We expected that survival models that incorporated recent growth would be better sup-ported than those using other factors known to influence tree survival. 2. We used a permanent plot network that representatively sampled a monodominant Nothofagus forest in New Zealand’s Southern Alps in 1974 and that was remeasured seven times through to 2009. The relationships were assessed using pre-earthquake growth and survival, pre-earthquake growth and post-earthquake survival (0–5 years post-earthquake), and post-earthquake growth and survival (5+ years post-earthquake). Sur-vival was related to growth of 4504 trees on 216 plots using Bayesian modelling. We hy-pothesised there would be a positive, logistic relationship between growth and survival. 3. Pre-earthquake, we found a positive, logarithmic growth–survival relationship at all eleva-tions. At higher elevations, trees grew more slowly but had higher survival, supporting our hypothesised demographic trade-off with elevation. As we expected, the earthquake al-tered the pre-earthquake growth–survival relationships and 0–5 years post-earthquake survival held little relationship with growth. Less expected was a strong, logarithmic growth–survival relationship that developed 5+ years post-earthquake because of en-hanced survival of fast-growing trees yet low survival of slow-growing trees. 4. Synthesis. Our findings demonstrate there can be trends in growth–survival relationships along an elevation gradient. If we assume a gradual climate warming is the equivalent of a forest stand shifting to a lower elevation, then data from our pre-earthquake period sug-gests that tree growth–survival relationships at any elevation could adjust to faster growth and lower survival. We also show how these novel growth–survival relationships could be altered by periodic disturbance.

1. Species performance in the realised niche is jointly shaped by both abiotic and biotic processes. Moreover, interactions between and within abiotic and biotic processes generate non-additivities, resulting in density dependence that varies in strength or even direction across environments. If ignored, these non-additivities can lead to inaccurate predictions of species responses to changes in environment and community composition. 2. There are increasing empirical efforts to test the constancy of pairwise biotic interactions along environmental and compositional gradients, but rarely along both. We address this gap using nationwide forest inventory data that span broad ambient temperature and moisture gradients throughout New Zealand. 3. We analysed tree diameter growth of six focal tree species as a function of neighbour densities and climate, while accounting for potential abiotic and biotic non-additivities arising from neighbour × climate and neighbour × neighbour statistical interactions, respectively. We kept the large number of parameters manageable using Bayesian shrinkage priors and interpretable using average predictive comparisons. 4. We found that the most complex model—featuring biotic interactions that changed with climate and higher-order interactions with intermediary species—had the highest predictive accuracy of tree diameter growth. Compared to climate, biotic interactions typically had stronger effects on tree diameter growth, especially when they were subjected to non-additivities from local climate and the density of a third species. Most non-additivities tended to weakly exacerbate pairwise competition, whereas the few strong non-additivities tended to alleviate pairwise competition or even produce pairwise facilitation. 5. _Synthesis:_ Our study highlights the importance of the interplay between abiotic and biotic processes when predicting how biotic interactions may structure communities under global change. When quantifying the relative importance of biotic and abiotic processes on species performance, we show that the conclusion varies depending on whether we are looking at direct or indirect effects. With accumulating evidence of non-additive biotic interactions, the next crucial step is to uncover their underlying mechanisms.