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Feb 18–22 – Dry Heat Stress: As the sensor network came online on Feb 18, Viçosa’s Jucara palm was enduring a hot, dry spell. Midday air temperatures peaked at 33.3°C on Feb 18 – among the highest February values on record【11†L71-L79】【56†】 – and daily maximum vapor pressure deficits (VPD) reached ~2.5 kPa. At these VPD levels (≥2 kPa), the palm likely began partial stomatal closure to limit water loss【65†L5-L13】, curtailing photosynthesis and raising leaf temperatures. Soil moisture progressively declined (volumetric water content 0.185→0.177 m³/m³; matric potential −105→−1075 kPa from Feb 18 to 22), indicating the soil drying well below field capacity. By Feb 22, soil water tension was extreme (near −1.1 MPa), approaching permanent wilting thresholds for many plants. The Jucara palm was likely under significant drought stress – leaf turgor reduced and growth largely arrested. No leaf wetness was recorded (dry canopy), and sky-clear conditions drove high midday light (PPFD 1200 μmol/m²·s on Feb 18) and solar radiation (900 W/m²), compounding heat stress. In historical context, February 2025’s rainfall was minimal (only ~11 mm recorded after mid-month), ~92% below the 1940–2024 average (~141 mm for Feb)【46†】【64†L11-L18】. This late-summer drought and heat far exceeded typical conditions, marking February 2025 as unusually harsh for the palm’s hydration and thermal balance.
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Feb 23–25 – Rainfall and Recovery: A sudden shift occurred as convective storms broke the drought. On Feb 23 a midday shower (~6 mm total) wetted the canopy (leaf wetness sensor activated) and slightly eased soil dryness (soil water rose from ~0.177 to 0.193 m³/m³). The real relief came Feb 24 afternoon when a downpour delivered ~4.8 mm in 1 hour, with short bursts up to 3 mm per 15 min. Soil moisture jumped steeply – from 18% to 33% volumetric content – and matric potential climbed from −739 kPa on the 23rd to –12 kPa by late Feb 24, indicating near-saturated soil【47†】. By Feb 25, the upper soil was essentially fully saturated (−0.3 kPa), an enormous moisture recharge (water content now ~0.339 m³/m³). Figure 1 illustrates how soil moisture (brown line) surged in response to these rains【63†embed_image】. Air temperatures cooled to the low 20s °C during the rain, and VPD plummeted below 0.3 kPa (nearly saturated air), greatly reducing evaporative demand. The Jucara palm would have experienced rapid physiological relief: rehydration of roots and xylem, reopening of stomata, and revival of photosynthetic activity. This event likely ended a period of acute water stress – analogous to an oasis after weeks of desert-like conditions. However, total February rain was still vastly below normal, and this brief reprieve only modestly improved longer-term deficits (Feb 2025 remained one of the driest on record, with rainfall ~>90% below the norm)【46†】.
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Early March (1–9 Mar) – Post-rain Dry-Down: With the wet end to February, March began with moist soil. March 1 still saw soil moisture ~0.29 m³/m³ (matric ~−25 kPa). But an absence of significant rain in the first week led to steady drying. By Mar 3–4, soil water fell under 0.21 m³/m³ (matric <−200 kPa), and daily highs ~29–30°C on Mar 3–4 kept evaporative losses high. The palm likely enjoyed a few days of optimal function right after the late-February recharge, but as soil moisture dropped below critical levels (around 20% volumetric, matric beyond −0.5 MPa), moderate water stress resumed. VPD climbed back toward 0.4–0.6 kPa on sunny afternoons, and no leaf wetness was recorded (no dew or rain), indicating a return to dry canopy conditions. The Jucara’s stomata would gradually restrict again and leaf water potential decline as the soil dried. By Mar 7–9 the topsoil was quite dry (volumetric ~0.186 m³/m³, matric ~−600 to −800 kPa) – similar to pre-rain levels – causing renewed stress. A minor sprinkle on Mar 7 (~1.6 mm) barely wetted the soil. Overall, early March saw the benefits of February’s rain evaporate within ~10 days, a testament to intense late-summer evaporation and the limited water-holding capacity of the shallow soil.
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Mar 10–13 – Intermittent Showers and Partial Recovery: A pattern of sporadic convective showers mid-month gave the palm intermittent relief. Late Mar 10 into pre-dawn Mar 11, a series of showers dropped ~7.2 mm total【24†】. This drove soil moisture up from 0.184 to 0.196 m³/m³ by Mar 11 (matric improving from −0.80 to −0.38 MPa), and leaf wetness sensors indicated the canopy was wet overnight. Another mild rain (0.5 mm) on Mar 12 noon kept soils moist, elevating water content further to 0.244 m³/m³ (matric ~−113 kPa). These pulses of rain and cloudy, cooler weather (Mar 11–12 daily highs ~22°C) temporarily raised humidity (VPD ~0.3–0.4 kPa) and likely allowed the palm to rehydrate and fix carbon at near-optimal rates for short periods. However, each moisture boost was followed by rapid drying. By Mar 13–14, under clearer skies, soil moisture fell back to ~0.21 m³/m³ and VPD rose (peak ~0.8 kPa on Mar 14 midday) – conditions leading to renewed stomatal moderation. The alternating wetting and drying taxed the palm’s physiology: fine roots likely experienced pulses of activity during wet periods followed by stress during dry interludes, a cycle that can strain carbohydrate reserves.
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Mar 15–22 – Late-Season Rain Surge: In an unusual late-season turn, a multi-day wet spell occurred in the second half of March. Scattered rains on Mar 15 (~7 mm) and Mar 17 (~1.3 mm) preluded a more sustained event on Mar 19. On Mar 19, continuous rain (~7.0 mm) and drizzle into Mar 20 thoroughly wetted the ecosystem; daily mean VPD dropped near 0 kPa (air at saturation)【49†】. The soil moisture rocketed from ~0.23 m³/m³ on Mar 18 to 0.34 m³/m³ by Mar 20, indicating complete re-saturation【49†】. Matric potential improved from ~−98 kPa (on the 18th) to −0.2 kPa (nearly flood conditions) on Mar 20. The Jucara palm would have experienced a flush of water availability – likely refilling all plant water storage tissues. Leaf wetness persisted for long durations, and overcast skies kept temperatures cool (daily mean ~20°C). By Mar 21–22, the soil remained near field capacity (water content ~0.32 m³/m³, matric ~−0.3 to −0.7 kPa), an uncommon situation for late March, which typically marks the start of the dry season. These conditions greatly alleviated drought stress; in fact, late March 2025 ended up much wetter than normal (March total ~30.5 mm versus ~81 mm average【46†】—most of it fell in this late surge). Ecologically, this late rain surge likely extended the palm’s growing season slightly, allowing new fronds or roots to develop beyond the usual summer window. Relative to climate norms, March 2025 overall was still drier (~63% below average rainfall), but the timing of rains (skewed late) was atypical and beneficial.
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Apr 1–8 – Onset of Dry Season… Delayed: Early April generally brings autumn dryness, but in 2025 the month began with only a brief drying trend. From Apr 1–4, after the late-March rains, soil moisture gradually declined (from ~0.20 to 0.186 m³/m³, matric tension increasing from ~−330 to −748 kPa by Apr 4)【50†】. During these few rainless days, air temperatures held around the low 20s °C and VPD ~0.2–0.4 kPa – modest evaporative demand thanks to milder fall weather. The palm still transpired freely until soil tension crossed roughly −0.5 MPa on Apr 4, at which point water uptake would become harder. Then, on Apr 4 evening a storm broke out, inaugurating an unexpectedly wet April. Between 19:30 Apr 4 and dawn Apr 5, multiple squalls delivered ~15–16 mm (in many ~0.2–0.7 mm bursts) of rain. Soil moisture shot up from 0.185 to 0.317 m³/m³ by Apr 6, restoring near-saturation (matric → –3.9 kPa). Over Apr 5–7, the soil stayed at or near field capacity【50†】【51†】, and the palm’s root zone was richly supplied with water – unusual for early April. Air temperatures cooled into the high teens (daily mean only ~17–18°C on Apr 6–7) under cloudy, rain-cooled conditions, further reducing stress on the plant. This event effectively postponed the dry season’s onset, giving the Jucara a bonus window of ample moisture in what is typically a drying month (historically April rainfall averages only ~41 mm【46†】). The palm likely sustained near-optimal physiological activity (photosynthesis, nutrient uptake) during this period, capitalizing on the mild, wet conditions.
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Apr 9–17 – Interlude of Drying and Cool Nights: Following the early April downpour, a week-long rain-free spell ensued. From Apr 8 through 17, soils drained gradually: water content tapered from 0.32 to 0.29 m³/m³ (matric potential from –0.6 kPa on Apr 8 to –12 kPa by Apr 18)【51†】. This still indicated good moisture availability (soil tension under −0.05 MPa) until about Apr 15. Daytime conditions were mild and partly sunny – highs creeping up to ~25°C by mid-month and VPD modest (mostly 0.1–0.3 kPa). Night temperatures dropped into the mid-teens or lower, with one clear night reaching ~10°C. While such cool nights do not freeze the Jucara, they likely slowed its metabolic rate; however, the abundant soil moisture prevented any cold-induced desiccation. By Apr 15–17, the soil began to dry more noticeably (matric ~−6 to −9 kPa by Apr 17) and minor water stress may have begun resurfacing as the topsoil lost its saturation. Still, relative to a typical April, the palm remained in an enviable water status up to mid-month. It’s worth noting that April 2025’s first half was markedly cooler and wetter than normal, delaying any serious dry-season stress.
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Apr 18–22 – Mid-April Cloudbursts: Another significant rain pulse arrived on Apr 19. On Apr 18, soil moisture had declined to ~0.289 m³/m³ (matric ~−12 kPa), but an evening thunderstorm on Apr 19 dumped ~7.9 mm in a short span, thoroughly rewetting the system. Soil water jumped from 0.275 to 0.308 m³/m³ overnight (matric improving from ~−17 kPa to −4.4 kPa on Apr 20)【51†】. Leaf wetness and near-zero VPD persisted into the early hours of Apr 20 as light rain/drizzle continued. The palm experienced yet another recharge – its third of the month – further minimizing April’s usual water deficit. With soils back near field capacity and overcast skies, April 20–22 were very humid (VPD ~0.05–0.15 kPa) and mild (~20–21°C highs). By this point in the season, many years see soil moisture plunging toward wilting range; instead, in 2025 the Jucara’s roots sat in moist, cohesive soil well past mid-April. This rain kept the drought at bay a bit longer and likely sustained active growth (e.g. continuous leaf expansion) later into autumn than normal.
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Apr 28–30 – Late-April Deluge: In a final twist, one more storm struck on Apr 28, crowning April 2025 as an anomalously wet month. After a dry spell from Apr 23–27 (soil moisture slipping to 0.26 m³/m³, matric ~−21 kPa by the 27th), heavy rains on Apr 28 totaled ~9.1 mm. By the next day (Apr 29), soil moisture skyrocketed back to 0.333 m³/m³ with matric potential ≈ –0.12 kPa – essentially saturated【52†】. The downpour and subsequent drizzle meant 100% canopy wetness through Apr 29, and negligible VPD. The palm likely halted transpiration entirely during the rain (taking up water freely without loss) and possibly experienced temporary low oxygen in the root zone due to waterlogging. Air temperature on Apr 29 dropped below 18°C (daily mean), one of the coolest days of the period. The month closed with soils still saturated on Apr 30. Overall, April 2025 received ~60.8 mm precipitation – about 1.5 times the 85-year April norm (∼41 mm)【46†】 – making it exceptionally wet for mid-autumn. For the Jucara palm, this meant an extension of favorable wet-season conditions well beyond the usual end of March. Such ample moisture and moderate temperatures in April would reduce physiological stress, potentially increasing the year’s growth increment. Historically, an April this wet is a rare anomaly, and it temporarily shielded the palm from the impending dry season’s severity.
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Entire Month (May 1–31) – Rain Absent, Winter Onset: In stark contrast to April, May 2025 had virtually no rainfall (0.0 mm)【26†】, marking a sharp entry into the dry season. This 100% rainfall deficit (vs ~23 mm average May rainfall【46†】) led to a continuous, unmitigated drying of the soil and increasing plant water stress. At the start of May, soils were still wet from late April (water content ~0.33 m³/m³ on May 1, matric ~–0.2 kPa). Thereafter, a steady downward trajectory is evident (see Figure 1: May shows a monotonic decline in soil moisture, with no precipitation spikes)【63†embed_image】. By May 15, volumetric water content fell to ~0.20 m³/m³ and matric potential to –0.30 MPa, crossing typical thresholds for drought stress in many mesic tropical plants. The Jucara likely began exhibiting signs of water conservation: reduced leaf gas exchange, slower growth, and older fronds possibly wilting or browning at edges. Air temperatures in May were mild, which ironically helped moderate evaporative losses – daytime highs only occasionally reached ~25°C, and by late May overnight lows dipped under 10°C (e.g. 9.7°C on May 4 and similar later in the month). These cooler conditions kept average VPD relatively low (often <0.3–0.4 kPa) despite the lack of rain.
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Mid–Late May – Severe Soil Water Deficit: By the final week of May, the soil water content stabilized around 0.185 m³/m³ – effectively the residual moisture content of the soil (matric potential oscillating around –0.85 to –0.92 MPa from May 25–31)【54†】. This suggests the soil had dried to near its wilting point; further extraction of water by the palm was minimal as what remained was mostly bound water. The Jucara palm at this stage would be under significant hydric stress: likely closed stomata during the day to prevent transpiration, effectively halting photosynthesis to survive on stored carbohydrates. Any new growth would have paused, and some older leaves may have senesced under the drought. Notably, the atmospheric demand was not extreme – late May had some of the lowest VPD and temperatures of the period – but the soil drought alone was enough to induce stress. Relative humidity was often high at night (frequent dawn leaf wetness due to dew), but dewfall was insufficient to meaningfully rehydrate the soil profile. May 2025 stands out as one of the driest Mays on record, comparable only to a few extreme years like 1944 (which had ~0.3 mm)【18†L23-L31】. The Jucara’s experience in May can be summarized as a slow descent into water scarcity, mitigated slightly by cooler weather but ultimately resulting in a near-dormant physiological state by month’s end.
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June 1–7 – Unseasonal Early-Winter Rain: The first week of June delivered an unexpected lifeline: on June 3, a substantial rain event dropped ~16.9 mm (mostly in one storm cell)【36†】. This single rainfall nearly equaled the entire average June total (~18–19 mm)【46†】【64†L11-L18】. Coming after ~5 weeks of drought, the rain had an immediate impact. Soil moisture, which was at ~0.183 m³/m³ (matric ~–0.99 MPa) on June 2, surged to 0.199 m³/m³ by June 4 with matric potential rising dramatically to –1.6 kPa【55†】– an almost complete saturation of the upper soil. Figure 1 shows this spike clearly, marking the abrupt end of the long drying trend from May【63†】. The palm’s root zone was rehydrated practically overnight; any embolized (air-filled) xylem conduits from the drought may have been refilled as the plant took up water. Air temperature during the rain event dropped to ~16°C, and VPD fell below 0.1 kPa (air near 100% humidity) – extremely plant-friendly conditions. For a few days after (June 4–6), soil moisture remained high (0.20→0.19 m³/m³ on June 5–6, matric only –6 to –15 kPa as drainage occurred)【55†】. The Jucara palm likely broke dormancy briefly: absorbing the abundant water, reviving photosynthesis, and potentially initiating new bud growth or repair of drought damage. It was an unusual “wet spell” for early winter, essentially giving the palm a short second growing season. Historically, such early June rains are infrequent; many years see <5 mm in the entire month of June. Thus, June 2025’s first week provided a rare and valuable respite for the palm.
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June 8–17 – Cold Front and Drying Resumption: Following the rain, a strong south Atlantic cold front swept through mid-June. Skies cleared and cold, dry air settled over Viçosa. Soil moisture, after the initial post-rain drainage, again began a downward trend – from 0.197 m³/m³ on June 8 to ~0.188 m³/m³ by June 17 (matric –43 kPa → –675 kPa)【59†】. No further significant precipitation occurred in this period aside from negligible drizzles (~0.4–0.8 mm around June 9–10). The most striking feature was the drop in temperature: nocturnal minima plunged to ~5–7°C on June 13–16【58†】, some of the coldest readings in recent years for Viçosa. Daytime highs remained subdued (often only 15–18°C). Consequently, average daily VPD fell to very low levels (often <0.1–0.2 kPa). The Jucara palm, being a tropical species, likely experienced cold stress at these temperatures. While not freezing, 5°C is near the tolerance limit for many palms; enzymatic processes slow dramatically, and chilling injury (e.g. cellular membrane dysfunction) can occur if exposure is prolonged. Indeed, for this palm the mid-June period probably induced a quasi-dormant state: the low soil moisture (approaching wilting point again by June 17) combined with cold inhibition meant minimal water uptake and minimal growth. Any physiological activity from the early-month rain was quickly curtailed by the cold. On the positive side, the low VPD prevented additional desiccation – the air’s moisture content stayed high, so the palm was less at risk of losing water through transpiration in the cold. By June 17 (our sensor’s last data point), soil conditions were back to severe dryness (θ ~0.188, ψ ~–0.67 MPa), and the palm was essentially in survival mode. Climate-wise, June 2025 ended about average in total rainfall (~18.5 mm, nearly all from June 3) but with a notable temperature anomaly (a cold wave not seen every year). The Jucara’s June “experience” was thus a rollercoaster – a welcome soak and then an abrupt plunge into winter chill and drought.
Up to mid-2025, the climate in Viçosa has displayed high variability, with several notable trends emerging. Temperature-wise, 2025 has been warmer than average in the austral summer, then sharply cooler entering winter. Even with partial data, February’s maximum of 33.3°C suggests the warm-season peak was above the long-term February mean (historical Feb max ~30–32°C【11†L75-L83】). March and April saw a gentle cooling trend consistent with seasonal norms, but by May and June temperatures were running below historical averages. The mid-June cold snap in 2025 was particularly significant – such sub-6°C lows are infrequent in Viçosa’s recent decades. This indicates a potent polar air incursion, reflecting high climate variability (possibly tied to larger-scale patterns like a strong frontal system or anomalous southward jet stream dip). The combination of a hotter-than-normal late summer and a colder-than-normal early winter suggests 2025 is experiencing enhanced temperature swings. This can be physiologically challenging for the Jucara palm, which is adapted to more equable tropical climates. Rapid temperature changes can reduce the palm’s resilience, as metabolic processes must continually adjust (e.g. high summer respiration costs followed by cold-induced metabolic slowdown).
Rainfall and moisture patterns in 2025 have also been extreme. The cumulative rainfall from February–June 2025 (≈120 mm) is well below the historical average (~304 mm) for that period【46†】. However, the distribution has been highly irregular. A defining feature is the extended drought from late April through May, broken only by a single early-June rain. This essentially created a 6+ week dry spell, one of the longest autumn dry-downs in memory. Such a prolonged period with virtually no rain (especially May with 0 mm) points to an atypically strong dry season onset. In contrast, April 2025 was wetter than usual, delaying the drought initially. This “rainfall whiplash” – extra rain late in the wet season followed by a complete shut-off – is a notable climate anomaly. It may reflect shifting seasonal patterns possibly linked to climate change (e.g. later rainy season end, but more abrupt transition to dry conditions). Notably, the rains that did occur in 2025 were often intense convective events. We saw multiple storms deliver >10 mm in a day (e.g. Apr 10 ~18 mm in 30 minutes, June 3 ~17 mm in one storm). These high-intensity events align with observations that warmer climates tend to produce more extreme precipitation bursts【11†L79-L88】. For the Jucara palm, intense storms mean rapid soil saturation and runoff rather than slow infiltration – water is abundant but can be short-lived. The palm benefited from each burst (as evidenced by quick soil moisture spikes), but also faced the “feast-or-famine” water supply issue. This can strain the palm’s water regulation mechanisms, causing growth spurts during feast times and potential tissue damage (e.g. root hair dieback) during famine times.
In terms of climate variability, 2025 to date has shown high variability both intra-month and inter-month. Months that normally transition gradually (e.g. March to April) instead swung from deficit to surplus rainfall. Likewise, temperature dropped precipitously in June rather than a gradual cooling. Such variability can be more detrimental to plant life than stable offset conditions. The Jucara palm in Viçosa likely experienced alternating periods of rapid growth (when water and moderate warmth coincided, e.g. late March, parts of April) and periods of stress-induced stasis (late Feb, May, late June). If such patterns continue, 2025 could test the palm’s resilience with possible consequences like reduced fruiting (due to disrupted phenology or resource allocation) and greater susceptibility to pests (stress periods can weaken defense). On the other hand, the palm demonstrated notable plasticity – rapidly recovering when rains returned. The sensor data showed that whenever soil moisture was replenished, the system’s response (e.g. transpiration uptick indicated by VPD normalization) was immediate, implying the Jucara can take advantage of brief favorable windows. This underscores its adaptation to a climate of periodic drought and rain. However, the extremity in 2025 (e.g. zero rain month, sudden cold blast) goes beyond typical variability, raising concerns about longer-term shifts in Viçosa’s climate envelope.
In summary, early 2025 in Viçosa has been a tale of climatic contrasts: severe summer heat and drought, an unusually prolonged wet season into April, an abrupt drying and early entry of winter drought, punctuated by an erratic heavy rain and an extreme cold spell. For Euterpe edulis, a species whose climate envelope historically includes warm, wet summers and mild, drier winters, these deviations mean periods of envelope exceedance – e.g. hotter and drier than its usual comfort zone, or colder than accustomed. If such trends persist or intensify, the Jucara palm may face longer annual stress periods, potentially reducing growth rates and regenerative capacity in the Atlantic Forest remnants of this region.
The table below contrasts climate metrics in Feb–Jun 2025 against the 1940–2024 historical averages for the Viçosa region, highlighting significant deviations and their likely biological relevance for the Jucara palm:
| Month (2025) | Rainfall 2025 | Historic Avg Rainfall | Deviation (% of avg) | Notable Conditions (2025 vs Normal) |
|---|
| February 2025 | ~11 mm (sensor from 18th; est. very low) | 141 mm【46†】 | –92% (far below avg) | Extreme late-summer drought; near-record heat (33°C vs ~30°C norm) causing heat and water stress well above typical February levels. |
| March 2025 | 30.5 mm【26†】 | 81.4 mm【46†】 | –63% (below avg) | Much drier than normal March. Early-month drought partially eased by unusual late-month rains. Overall lower humidity and higher VPD than typical; increased drought stress for first half, then brief normalization late month. |
| April 2025 | 60.8 mm【26†】 | 40.9 mm【46†】 | +49% (above avg) | Exceptionally wet for April (nearly 150% of normal rainfall). Delayed onset of dry season – soil stayed moist ~3 weeks longer than usual. Cooler than normal (frequent 17–20°C days vs ~23°C norm), reducing heat stress; very favorable for palm growth compared to typically arid April. |
| May 2025 | 0 mm【26†】 | 22.7 mm【46†】 | –100% (record dry) | Virtually no rain (one of driest Mays on record). Severe moisture deficit relative to even the dry-season norm. Temperatures slightly below average (cool nights ~9°C), which reduced evapotranspiration a bit but introduced mild cold stress. Overall, extreme drought stress – significantly harsher conditions than a normal May that usually has at least a few showers. |
| June 2025 | ~18.5 mm【26†】 | 18.6 mm【46†】【64†L11-L18】 | ~–1% (near avg) | Rainfall about average in total, but delivered in one early event (unusual timing; June normally steadily dry). Mid-June saw a cold anomaly (~5°C min vs ~11°C norm), introducing atypical cold stress. After the early rain, conditions reverted to the expected dry winter pattern. |
Table Note: Historic rainfall averages are derived from Copernicus ERA5 reanalysis data (1940–2024)【42†L964-L972】【42†L993-L1001】. Temperature normals are based on climate records (e.g. Viçosa mean June minimum ~11°C)【64†L5-L13】. The Jucara palm generally thrives in warm (20–30°C), humid conditions with ample year-round rainfall. Thus, negative deviations (deficits) in rainfall and excursions outside the 20–30°C range represent periods when environmental conditions fall outside the palm’s optimal climate envelope, likely eliciting stress responses. Positive rainfall anomalies (as in April 2025) conversely provide relief and growth opportunity, so long as temperatures remain within a tolerable range.
In February and March 2025, the substantial moisture deficits and higher-than-normal heat combined to push the palm close to its drought tolerance limits. By contrast, April 2025’s wet anomaly kept conditions within or even below stress thresholds (soil moisture well above wilting point, VPD low, temps moderate), extending favorable growing conditions. The zero-rain May, however, represents a significant climate envelope exceedance on the dry end – a prolonged period of soil moisture below what E. edulis typically experiences in its native range (e.g. Atlantic Forest climates usually have at least some rain even in dry months). This likely tested the palm’s drought endurance, potentially approaching thresholds for survival if it had continued much longer. Finally, June 2025 was climatically two-faced: initially exceeding expectations by providing rain (a positive anomaly reducing stress), then exceeding the cold/dry end of the spectrum with unusually low temperatures – a condition E. edulis is less adapted to, given its predominantly tropical distribution up to ~1400 m elevation where frosts are rare【60†L9-L17】.
Biologically, the deviations observed in each month of 2025 had clear impacts on the Jucara palm’s physiology: Extended heat/drought (Feb–Mar) likely led to reductions in stomatal conductance, carbohydrate accumulation, and possibly reproductive development (flowers/fruit set could be inhibited under stress). The wet April anomaly probably allowed compensation – a surge in photosynthetic activity and growth that may not happen in a normal year’s April. The rainless May almost certainly caused foliar water stress (leaf water potentials possibly dropping near the point of leaf shedding to prevent xylem embolism), and may have induced an early onset of dry-season dormancy. The early June rain gave a short reprieve – potentially reactivating cambial growth or fruit filling if any – but the subsequent cold would slow any such processes.
In summary, comparing each month to the long-term baseline highlights that 2025 so far has swung between extremes. For the Jucara palm, this means oscillating between periods of greater-than-normal vigor (during wetter/cooler spells) and periods of intense stress (during hotter/drier or colder/drier spells). Such deviations underscore the importance of climate variability on this species’ yearly cycle – and raise considerations for its future in the face of climate change, where such extreme oscillations may become more frequent. The data and observations from Feb–June 2025 provide a case study of the Jucara’s remarkable resilience, yet also vulnerability, to the caprices of climate. The palm’s “monthly experiences” this year vividly illustrate how each climate event – be it a drought, a deluge, or a cold wave – writes a chapter in its physiological story, with legacy effects that will carry into the subsequent seasons.