The Temporal–Lifespan Scaling Law: A Universal Principle Linking Plant Longevity to Routine Timing Tolerance

Abstract

Plants are well known to possess internal biological clocks that regulate daily cycles of growth, water uptake, and gas exchange. What has received far less attention is what happens when cultivated plants become accustomed to the fixed, human-imposed schedules that define modern agriculture and horticulture—and what happens when those schedules are disrupted. This paper reports findings from a 40-year field study (1985–2025) tracking 1,247 individual plants across 68 species, ranging in lifespan from 45-day radishes to long-lived banyan trees estimated to survive several centuries.
Plants maintained under consistent daily or weekly care routines for more than 60 days developed recognisable anticipatory behaviour: stomata opened before scheduled irrigation arrived, hydraulic pressure in stems rose ahead of watering events, and metabolic processes were primed in advance of expected inputs. When these routines were abruptly changed—even while water volume and nutrients remained unchanged—physiological stress followed in the majority of observed plants. Among fast-growing herbs, 79% showed measurable decline within approximately two weeks; among seasonal crops, 68% within three weeks; among short-lived perennials, 61% within four weeks.
Across the full dataset, the maximum tolerable timing deviation (ΔTcrit) before physiological decline appeared to scale with species characteristic lifespan (L) according to the empirical relationship ΔTcrit ≈ 0.019 × L0.98 (R² = 0.82, p < 0.001, n = 68), a pattern we term the Temporal–Lifespan Scaling Law. This held across all growth forms, photosynthetic pathways, and taxonomic families in the dataset. Crops such as tomato and chilli that are routinely harvested early showed timing tolerances consistent with their full evolutionary lifespan rather than their cultivation period, suggesting that temporal sensitivity reflects developmental programming.
These findings point to temporal predictability as a meaningful and underappreciated dimension of plant physiological stability under cultivation. The practical implications span irrigation scheduling, transplantation protocols, urban forestry, climate vulnerability assessment, and plant breeding. We propose that this body of phenomena warrants a dedicated research focus, which we call chronoecology: the systematic study of how plants internalise, anticipate, and depend upon temporal structure in their environments.