Rewilding, a conservation approach that gained its name in the 1980s, aims to restore self-willed ecosystems in which natural processes — including stochastic disturbance and the activity of wild grazers — operate with minimal human control. The classic formulation proposed by Soulé and Noss emphasized large protected cores, connecting corridors, and keystone carnivores, but modern European projects have broadened the idea to include the passive reversion of farmland. At Arger Fen, fields taken out of arable production between 2004 and 2014 were simply left alone: no fertilizer, no livestock during the study period, no active conservation management. Succession was allowed to run its course, converting former cropland into a mosaic of rough grassland and scrub.

The four study fields differed sharply in their terrain. Two were almost perfectly flat, with mean slope gradients of just 0.6 percent, while the other two sloped from very weak to moderately steep, reaching gradients of up to 10.9 percent and a vertical relief of 27 meters. All had been plowed and cropped before 2014, producing maturing grassland swards comparable to other ex-arable rewilding sites in Suffolk. The researchers walked 400-meter W-shaped transects through each field three times between May and August 2021, recording adult Orthoptera both visually and by ear, since stridulating males of most local species call at frequencies within human hearing range.

Six species were recorded, all widespread in Suffolk: the meadow grasshopper Pseudochorthippus parallelus, Roesel’s bush-cricket Roeseliana roeselii, the long-winged conehead Conocephalus fuscus, the field grasshopper Chorthippus brunneus, the lesser marsh grasshopper Chorthippus albomarginatus, and the dark bush-cricket Pholidoptera griseoaptera. Overall density reached 1,221 adult grasshoppers per hectare — more than five times the 234 adults per hectare recorded at Black Bourn Valley, a flatter rewilding site 30 kilometers to the north. The comparison hints that topographic variety itself may boost carrying capacity for these insects.

The statistical patterns were striking. There was strong evidence that C. brunneus, the field grasshopper, was far more abundant on slopes — it made up 27 percent of adult detections in sloping fields but only 1 percent in flat ones. The long-winged conehead showed the opposite pattern, strongly preferring flat ground, where tall coarse grasses such as cock’s-foot grow in the moist soil at the base of slopes. Species diversity, measured with the Shannon-Wiener index, was significantly higher in the sloping fields, and linear regression confirmed that species richness and diversity both increased with slope gradient, with very strong evidence for the diversity relationship.

What makes slopes so attractive to some species? The answer appears to lie partly in the activities of wild lagomorphs. Brown hares and rabbits grazed the sloping fields far more heavily than the flat ones — droppings and burrow excavations were both significantly denser on slopes, and regression showed very strong positive relationships between slope gradient and rabbit excavations. This grazing and digging created patches of exposed soil, which the field grasshopper needs for egg-laying and basking. Bare ground warms quickly in sunshine, offering the hot microclimates that grasshopper eggs and nymphs require for development.

The study also suggests an intriguing movement pattern. Nymphs of all species were more abundant in flat fields, yet adult C. brunneus concentrated on slopes. The authors propose that nymphs hatch on flatter ground and then move uphill as they mature, seeking out the lagomorph-grazed bare soil patches for oviposition — a lifecycle choreography shaped by the interaction between topography and wild grazing. Early-instar grasshoppers are known to favor short grassland near hatching sites before dispersing into taller swards as they develop.

Not every finding pointed the same way. The meadow grasshopper and Roesel’s bush-cricket showed moderate evidence of preferring flat ground, and the two bush-crickets that have expanded their British ranges northward with climate change — R. roeselii and C. fuscus — were early colonists of the flat post-arable grassland, where tall vegetation offers shelter and oviposition sites. Meanwhile, an unexpected player entered the story: ash dieback disease. In Hullback’s Grove, a small stand of ash saplings killed back by the fungus Hymenoscyphus fraxineus maintained an open mosaic of grass and scrub that would otherwise have shaded out as the canopy matured. All six Orthoptera species were detected in this diseased hillside patch, illustrating how stochastic natural disturbances — even devastating ones — can generate habitat heterogeneity that conservation managers would struggle to replicate.

The authors acknowledge limitations. Only two fields of each type were studied, the surveyor’s ear cannot detect the conehead’s ultrasonic 30-kilohertz call without equipment, and dropping counts may have been easier to spot in short grazed vegetation than in tall moist sward. Still, the combined visual-acoustic method detected all six species, and the technique is considerably less time-intensive than automated acoustic detectors for low-frequency callers.

The broader message is one for anyone planning a rewilding scheme: topography matters. Flat ex-arable land tends toward an open layer of fine-leaved grasses with a warm microclimate, but limited coarse grasses for feeding, whereas undulating terrain with slopes creates a patchwork of microclimates, soil drainage regimes, and vegetation structures. The authors postulate that rewilding schemes on arable land may be particularly effective when they incorporate topographic undulations — both flat areas and hillsides — to promote the greatest diversity of Orthoptera. At Arger Fen, the heathy acid grassland of the historic Leavenheath common, enclosed after 1817, appears to be re-establishing on the slopes, with the near-threatened annual common cudweed already returning. If that trajectory continues, the field grasshopper populations there — currently 542 to 700 adults per hectare on slopes — may climb toward the 1,500 to 3,100 adults per hectare seen on long-established heathland, a quiet testament to what happens when the land is simply allowed to be itself, bumps and all.

Subject of Research: Influence of topographic heterogeneity on Orthoptera diversity and abundance in a rewilding scheme on former arable land

Article Title: Topographic heterogeneity influences diversity and abundance of Orthoptera in a rewilding scheme

Article References: Gardiner, T., & Casey, D. (2024). Topographic heterogeneity influences diversity and abundance of Orthoptera in a rewilding scheme. Journal of Orthoptera Research, 33(2), 255-266. https://doi.org/10.3897/jor.33.119897

Image Credits: AI Generated

DOI: 10.3897/jor.33.119897

Keywords: rewilding, Orthoptera, grasshoppers, bush-crickets, topography, slope gradient, Arger Fen, Suffolk, lagomorph grazing, ash dieback, biodiversity, habitat heterogeneity

The study was conducted in 2024 at the Tekirdağ Viticulture Research Institute, in a rainfed vineyard whose elevation ranges from roughly 47.45 to 55.46 meters above sea level. The researchers divided the block into three slope positions—lower, middle, and upper—and examined vines grafted onto 5BB rootstock and trained in a bilateral cordon system. Because the vineyard receives no irrigation, every vine depends entirely on rainfall and soil water reserves, making the site a natural laboratory for observing how water availability, which typically declines upslope, translates into physiological and biochemical change.

Across the growing season, the team measured net photosynthesis, stomatal conductance, transpiration, and two measures of water use efficiency on eleven separate occasions, under climatic conditions spanning air temperatures of 30 to 38 degrees Celsius, relative humidity of 26 to 50 percent, and photosynthetically active radiation from 600 to 1800 micromoles per square meter per second. These repeated field measurements captured how the vines responded to genuinely fluctuating Mediterranean summer conditions rather than a single snapshot, giving the dataset unusual ecological realism for a physiological study.

The results revealed a clear stress gradient running up the hill. Vines at the upper slope position showed lower rates of photosynthesis and stomatal conductance than their lower-slope counterparts, but they achieved higher water use efficiency—both in terms of carbon gained per unit of water lost through stomata and per unit transpired. In other words, the upslope vines were running a conservative water-use strategy, keeping their stomata tighter to conserve moisture at the cost of slower carbon assimilation. This is a classic drought-avoidance signature, and its emergence along a purely topographic gradient underscores how strongly slope position governs vine water status even within a single, seemingly uniform vineyard.

Biochemical analyses reinforced the physiological picture. Chlorophyll a, chlorophyll b, and total chlorophyll contents all decreased as one moved upslope, consistent with stress-impaired pigment metabolism, while the ratio of chlorophyll a to b increased—a shift often associated with acclimation to harsher light and water conditions. Meanwhile, the stress-signaling hormone abscisic acid, total phenolics, and tannins all rose with slope position. Abscisic acid is the plant hormone that orchestrates stomatal closure under drought, so its upslope accumulation dovetails neatly with the observed reduction in stomatal conductance and the shift toward water conservation.

Perhaps the most striking results came from high-performance liquid chromatography profiling of individual phenolic compounds. Gallic acid, vanillic acid, syringic acid, caftaric acid, chlorogenic acid, caffeic acid, catechin, epicatechin, rutin, and kaempferol all accumulated more abundantly in vines at the middle and upper slope positions. These compounds are not merely metabolic byproducts; they form a chemically diverse defensive shield, scavenging reactive oxygen species generated when photosynthesis is stressed, reinforcing cell walls, and deterring pathogens. Their upslope enrichment suggests that vines facing tighter water budgets invest more heavily in secondary metabolism, effectively trading growth and carbon gain for chemical resilience.

To test whether these patterns were statistically robust rather than incidental, the researchers applied principal component analysis and hierarchical clustering to the full dataset. Both multivariate approaches cleanly separated the three slope positions, with the upper slope clustering alongside the key stress markers—elevated abscisic acid, phenolics, tannins, and water use efficiency, and depressed chlorophyll and photosynthesis. Bivariate correlation analysis added a further layer: photosynthesis was negatively linked with abscisic acid, intrinsic water use efficiency, and phenolic concentrations, exposing an explicit trade-off between carbon assimilation and defense investment. A vine cannot maximize both at once, and the slope dictates where along that continuum each plant sits.

Proline, a compatible osmolyte that helps cells maintain turgor under water deficit, was also measured, along with antioxidant capacity assessed by the TEAC assay. Together with the hormone and pigment data, these measurements sketch a coherent portrait of ‘Adakarası’ as a cultivar with genuine drought resilience. Rather than collapsing under upslope stress, the vines reprogrammed their physiology and secondary metabolism in an apparently coordinated fashion—closing stomata, signaling with abscisic acid, accumulating osmoprotectants, and ramping up phenolic defenses. Such integrated plasticity is precisely the trait profile that breeders and growers seek as climate zones for quality viticulture shift poleward and upward.

The work also speaks to the concept of terroir, the oft-invoked idea that place imprints itself on wine. While terroir is usually discussed in terms of soil, mesoclimate, and tradition, this study demonstrates that within-vineyard topography alone can generate measurable gradients in leaf chemistry and gas exchange. Slope-driven differences in soil water content, erosion, and solar exposure appear sufficient to push vines into distinct physiological and metabolic states—states that plausibly influence berry composition and, ultimately, wine character. For precision viticulture, the message is that slope position deserves attention not just at the scale of hillsides and valleys, but within individual blocks.

For the Turkish wine industry, the stakes are concrete. ‘Adakarası’ is a heritage variety native to Thrace, and preserving its cultivation under a warming, drying climate depends on understanding where it thrives and why. By identifying the upper slope as a zone of conservative water use and heightened phenolic defense, and the lower slope as one of freer gas exchange, the study offers growers a physiological rationale for vineyard design, rootstock and scion matching, and future irrigation decisions. More broadly, it shows that a humble hillside, read carefully through the language of pigments, hormones, and polyphenols, can teach us how one of humanity’s oldest crops negotiates the stress of a changing world.

Subject of Research: Slope-induced abiotic stress effects on leaf phenolics and physiological activity in the grapevine cultivar Vitis vinifera 'Adakarası'

Article Title: Leaf phenolics, physiological activity and abiotic stress relationship induced by slope in grapevine: Vitis vinifera ‘Adakarası’

Article References: Candar, S., Alço, T., Seçkin, G. U., Şahin, E., Demirağ, O., Güngör, T. A., Bahar, E., & Korkutal, İ. (2026). Leaf phenolics, physiological activity and abiotic stress relationship induced by slope in grapevine: Vitis vinifera ‘Adakarası’. Plant Biosystems, 160(4), Article 217. https://doi.org/10.1007/s44473-026-00228-z

Image Credits: AI Generated

DOI: 10.1007/s44473-026-00228-z

Keywords: grapevine, Vitis vinifera, Adakarası, drought stress, phenolic compounds, abscisic acid, photosynthesis, water use efficiency, chlorophyll, slope gradient, viticulture, climate change