This editorial is the first in a micro-geography series examining how governmental environmental narratives actually manifest spatially on the ground. Using Midpeninsula Regional Open Space District and Bear Creek Redwoods Open Space Preserve as a case study, the series examines the gap that can emerge between public-facing environmental policy and the lived reality of managed landscapes during ecologically sensitive periods such as nesting season.
Midpen’s “Mowing to Mimic Nature” narrative and the reality at Bear Creek Redwoods: When “timing is everything” meets the realities of nesting season
On a recent hike, Bear Creek Redwoods Open Space Preserve sounded more like an active work zone than an open space preserve in the middle of nesting season. Chainsaws and weed whackers echoed across the landscape, at times drowning out the calls of nesting birds as I moved through the preserve.
What stunned me was coming upon a meadow that, just three weeks earlier, had been tall with dense spring vegetation including native wildflowers. Still-green drying grass lay scattered across short cropped stubs, with visible mower striations cutting back and forth across the hillside. I could see only blackbirds, a species known for exploiting freshly disturbed agricultural fields, along with a few California scrub jays pecking at the exposed ground.
Around that same time, Midpen published a stewardship article about mowing grasslands in spring titled “Timing is Everything” with an additional heading named “Mowing to Mimic Nature.” There was no mention of the native ground nesting birds specific to grassland habitats in this short piece.
Read alongside Midpen’s own management documents and nesting bird guidance, the article felt strikingly out of alignment with both the ecological complexity of spring mowing and the conditions visibly unfolding at Bear Creek Redwoods Preserve during peak breeding season.
The issue was not simply that the article oversimplified a complicated ecological issue. The stewardship narrative entirely omitted the biological importance of nesting birds during peak breeding season while simultaneously presenting spring mowing as beneficial ecological stewardship rooted in natural disturbance.
In several cases, the stewardship framing directly conflicted with both established grassland ecology and Midpen’s own scientific and management guidance elsewhere.
Fire, grazing, and the biological importance of timing
The deeper ecological issue is timing. In California grassland ecosystems, spring is one of the most biologically sensitive periods of the year.
Spring is when ground nesting birds are active in grasslands
By early May, many birds are actively nesting, incubating eggs, feeding nestlings, and relying on dense seasonal vegetation for concealment and protection from predators. In healthy spring grasslands, much of this activity remains hidden beneath the vegetation itself. Meadowlarks call from concealed perches beneath dense grassland cover. California quail move through low vegetation while horned larks, fox sparrows, and other grassland-associated birds rely on seasonal vegetation structure for nesting and concealment.
Disturbance during this period can expose nests, remove cover, interrupt feeding behavior, and increase the likelihood of nest abandonment or nest failure.
Midpen’s own ecologically sensitive preserve management policies discourage spring vegetation work
That heightened ecological sensitivity is precisely why many wildlife management frameworks emphasize avoidance during breeding season. One of Midpen’s own grassland planning documents acknowledges this directly, stating:
“Spring mowing shall not occur because of potential impacts to ground nesting bird species.”
Yet Midpen’s public-facing stewardship article ignored that biological conflict by avoiding any meaningful discussion of nesting birds, instead presenting spring mowing as mimicking “natural disturbance” comparable to fire and wildlife grazing.
That lies in direct contrast to this statement on Midpen’s Wildland Fire Resiliency page:
As part of Midpen’s ecological approach to vegetation management, we are careful not to impact sensitive plants and wildlife. One way we do this is to avoid work during nesting bird season, which ends September 1.
Scientifically, those comparisons are far more complicated than the article suggests.
Mowing does not mimic the ecological functions of wildfire
The comparison to wildfire is also ecologically misleading. Although mowing reduces vegetation height, it does not reproduce many of the ecological functions associated with fire, including nutrient recycling, stimulation of some native plant germination, and the removal of accumulated organic material from the landscape. Mechanized mowing and wildfire are fundamentally different ecological processes.
Timing wise, research on Native American burning practices similarly indicates that burning was often tied to later seasonal cycles, including late summer post-harvest and fall burning periods.
Patchy wildlife grazing versus uniform mowing
Wildlife grazing also functions very differently from mechanized mowing. California grasslands are naturally shaped over time by uneven grazing pressure, seasonal wildlife movement, indigenous burning, and patchy disturbance patterns that create diverse vegetation structure across the landscape.
By comparison, mechanical mowing is rapid, uniform, and non-selective, reducing vegetation across broad areas to the same height all at once.
That simplification was visible in the meadow itself, where what had recently been dense spring vegetation had been flattened into short uniform stubble across the field.
Mowing is not a simple solution for invasive species
The article’s portrayal of invasive species management was similarly incomplete.
Scientific literature on mowing in California preserves is considerably more nuanced than the stewardship narrative suggests. Researchers generally agree that mowing can help suppress some invasive grasses under specific conditions, but ecological outcomes depend heavily on timing, scale, intensity, frequency, and what species are present on the landscape.
In other words, mowing is not a universally “one size fits all” tool for dealing with invasive species.
Midpen’s own planning documents further contradict the simplified stewardship narrative surrounding invasive species management. For example, a Midpen ecological report discussing yellow star-thistle management states:
“Mowing is not an effective control method because plants in the rosette stage generally grow below the height of a mower bar and because the robust taproot will resprout if top growth is removed.”
Other invasive species management guidance similarly warns that mowing yellow star-thistle can stimulate lower branching growth, reduce effectiveness, or increase seed production if timing and cutting height are not precise.
In other words, even Midpen’s own technical management documents acknowledge limitations and ecological tradeoffs largely absent from the simplified stewardship framing presented to the public.
Mowing in spring prevents native wildflowers from seeding
Many native wildflowers in the Santa Cruz Mountains are still actively flowering or setting seed during May. Broad mowing during this period therefore does not selectively remove only invasive vegetation.
It can also remove native annuals before seed production, reduce floral resources relied upon by pollinators, simplify habitat structure, and eliminate dense spring vegetation many nesting birds depend on for concealment during breeding season.
The meadow at Bear Creek still contained actively growing spring vegetation when it was cut, underscoring how broad mowing during this period affects far more than invasive weeds alone.
The same late spring conditions that may make mowing operationally useful for some vegetation management goals also overlap directly with peak nesting season, when many grassland birds are incubating eggs, feeding nestlings, and relying on dense vegetation for protection and concealment.
The contradictions of Midpen’s ecological messaging
Taken together, these contradictions reveal a much larger problem with Midpen’s “Mowing to Mimic Nature” narrative. The stewardship article presented spring mowing as straightforward ecological management rooted in natural disturbance. Yet Midpen’s own planning documents, broader ecological research, and the biological realities of spring grasslands all point toward a far more complicated picture involving nesting-season sensitivity, invasive species uncertainty, habitat simplification, and significant ecological tradeoffs.
At Bear Creek Redwoods Preserve, the simplified stewardship narrative presented in “Mowing to Mimic Nature” looked very different once viewed against the biological realities of spring grasslands, where recently flattened meadow grasses, construction machinery, and ongoing vegetation removal had already altered the landscape during peak nesting season.
Midpen’s own stewardship messaging increasingly highlights this contradiction. In a separate restoration article about work in Sierra Azul Preserve, Midpen specifically emphasized completing vegetation work within a narrow seasonal window to avoid impacts to nesting birds and bats. That avoidance-first ecological framing stands in sharp contrast to the spring mowing and disturbance occurring at Bear Creek Redwoods during peak nesting season.
Next in this series: a closer look at two proposed construction projects at Bear Creek Redwoods Preserve during nesting season, and the growing tension between Midpen’s public emphasis on nesting bird avoidance and efforts to reduce protective nest buffers to allow construction activity to proceed during breeding season.
References
“Timing Is Everything.” Midpeninsula Regional Open Space District, Midpeninsula Regional Open Space District, 2026, Midpen “Timing Is Everything” article.
Mindego Hill Rangeland Management Plan – Amendment 1 (August 2019), Midpeninsula Regional Open Space District.
United States Department of Agriculture Forest Service. Yellow Starthistle Field Guide. U.S. Forest Service, 2017, USFS Yellow Starthistle Field Guide PDF.
United States Geological Survey. Fire History of the San Francisco East Bay Region and Implications for Landscape Patterns. U.S. Geological Survey, USGS fire history publication.
