Ecological Pressures on Fire Island

Fire Island exists inside a maritime forest shaped through long succession. Each plant here evolved within a web of fungal, insect, bird, and soil relationships that stabilize sand and build resilience. When species arrive without those long coevolved relationships, the balance shifts.  In their home forest, they may be preparing disturbed soil for the success of an entire ecology.  Those relationships will never emerge here, and in that lonely expansion, many deep relationships are harmed.

Southern pine beetle, Dendroctonus frontalis, has reshaped much of the pine canopy on Fire Island over the past decade. Warmer winters have allowed beetle populations to expand northward, increasing pressure on pine systems across the region.

The beetle does not limit itself to a single species. It attacks stressed pines. In the Pines, both native pitch pine (Pinus rigida) and planted Japanese black pine (Pinus thunbergii) can become infested. When populations build, beetles bore through bark, introduce blue stain fungi, and disrupt the tree’s vascular system. Infested trees may show small pitch tubes on the bark, fine reddish boring dust at the base or lodged in bark crevices, and a rapid shift in needle color from green to yellow to red brown. Once colonized, beetles can complete multiple generations within a single growing season.

Both pitch pine and Japanese black pine tolerate salt and sand very well. Away from its native ecological context, however, black pine is also affected by pressures such as pine wilt disease, scale insects, and fungal blights that can lead to premature decline and increased susceptibility to beetle attack.

Pitch pine is the defining pine of this forest. In many lots they tower like charismatic giants, several likely more than a century in age. They give scale to the dunes, shade to our homes, and structure to the maritime forest system. Having evolved within this system, they support insects, birds, and the broader ecological community that depends on native canopy. It matters to this forest that we guard these remarkable beings.

We are grateful to the Pines Conservation Society and FIPPOA for their annual removal of beetle infested trees along public paths. Yearly winter intervention in shared areas has reduced hazard risk and slowed spread significantly.

Local responsiveness matters. Coordinated stewardship across properties reduces risk, protects canopy structure, and sustains the beauty and function of this forest system. A tree that expresses active infestation in spring, shortly after winter removals, can produce additional generations across the warmer months. Left standing, such a tree becomes an active source within the local canopy, releasing beetles multiple times through spring and summer. With increased responsiveness across the community, we believe this pressure can be reduced further.

Fire Island exists inside a maritime forest shaped through long succession. Each plant here evolved within a web of fungal, insect, bird, and soil relationships that stabilize sand and build resilience. When species arrive without those long coevolved relationships, the balance shifts.  In their home forest, they may be preparing disturbed soil for the success of an entire ecology.  Those relationships will never emerge here, and in that lonely expansion, many deep relationships are harmed.

Phyllostachys species

Running bamboo spreads through extensive underground rhizomes that travel laterally beneath the soil surface. These rhizome networks form dense mats that suppress native regeneration and reduce space for understory shrubs and young trees.

Above ground, bamboo creates tall monocultures that alter light levels and moisture dynamics. Below ground, the dense rhizome structure can compact and reorganize soil in ways that limit native root establishment.

Over time, canopy trees adjacent to large stands often show stress, decline, or death as a monoculture of bamboo increases.

Brookhaven Town Code prohibits the uncontrolled spread of running bamboo beyond property boundaries. Yet mature stands remain across portions of the Pines, including low corridors where intact holly and other native species still persist within expanding thickets.

Where full excavation is feasible, removal of rhizome systems offers the clearest path to restoration.

Where immediate removal is not practical, transition can occur in phases. Repeated seasonal cutting weakens rhizomes. At the same time, native shrubs and trees can be planted to establish living privacy screens and long-term canopy. As native root systems mature and soil structure rebuilds, remaining bamboo can be removed incrementally.

This approach distributes cost and labor over time while moving steadily toward forest recovery.

Phragmites australis

Phragmites australis forms dense, nearly impenetrable stands that suppress native shrubs and redirect natural succession along wetland edges, low corridors, and forest margins.

Its thick litter accumulates year after year. As that material decomposes, it alters soil chemistry and reshapes microbial communities in ways that favor its own expansion while making reestablishment difficult for native plants. Nitrogen cycling shifts. Light levels drop. What was once a diverse mosaic becomes uniform.

Below ground, extensive rhizome networks knit tightly through the soil, reducing space for native root systems and limiting regeneration. Expansion is not accidental. It is structural.

As stands mature, tall dry canes remain upright through winter, increasing surface and ladder fuels. Fire behavior in dense invasive grass systems can differ significantly from native understory communities, producing hotter, more continuous burns under the right conditions. In a residential forest, that shift matters.

Disturbed soils within and around phragmites stands often invite secondary colonizers. Poison ivy, though native and ecologically functional, can proliferate in these dense thickets. When vegetation containing poison ivy burns, urushiol can become airborne, posing serious respiratory risk to residents and to the firefighters who respond.

Reduction of phragmites requires sustained seasonal effort and careful biomass handling. Lasting recovery depends on replacing removed stands with native species that rebuild soil structure, restore fungal relationships, and return layered habitat to the land.

Miscanthus sinensis

Chinese silver grass resembles native switchgrass (Panicum virgatum) in form and movement, and its plumes now appear across the Pines, introduced as a garden trend and taking root beyond garden boundaries.

At a glance, the two grasses seem interchangeable. Ecologically, they are not.

Switchgrass is native to this region. It stabilizes sandy soils, participates in dune and upland succession, and supports a wide range of native Lepidoptera larvae, the caterpillars of our gorgeous moths and butterflies that also provide essential protein for nesting birds.

Miscanthus does not share deep coevolution with this maritime system. While it forms typical grass root associations, it contributes minimally to the specialized insect relationships that anchor native food webs. It may resemble switchgrass in silhouette, but it does not carry the same ecological weight.

Miscanthus spreads readily by wind-dispersed seed and has escaped cultivation in multiple northeastern states. Seedlings are now establishing beyond intended planting areas, including unmanaged corridors and edges of protected lands. As it expands, it competes aggressively in early successional sandy soils and can displace native grasses that would otherwise build soil and support wildlife diversity.

New York State and other northeastern jurisdictions recognize Miscanthus sinensis as invasive or emerging invasive. Even cultivars once marketed as sterile have demonstrated viable seed production under field conditions.

While we respect private decorative choices, some trends fade for good reason. In a forest shaped by deep evolutionary relationships, resemblance is not equivalence. We encourage thoughtful transition toward native grasses that sustain the living architecture of this island.

We are living in a period when small decisions accumulate quickly. A tree left standing through one growing season can release multiple generations of beetles. A grass planted for texture can seed into federal land. A pathogen can move through root grafts silently until a canopy shifts.

Stewardship now determines the fate of our forest.

Ecological systems depend on coevolved relationships. The maritime forest has always known how to hold this island. When we align with those relationships, it continues to hold us beautifully.

Additional plants currently exerting pressure in and around the Pines include:

Garlic mustard (Alliaria petiolata)

Oriental bittersweet (Celastrus orbiculatus)

Japanese honeysuckle (Lonicera japonica)

Multiflora rose (Rosa multiflora)

Japanese knotweed (Fallopia japonica)

Mugwort (Artemisia vulgaris)

English ivy (Hedera helix)

Chinese wisteria (Wisteria sinensis)

Japanese barberry (Berberis thunbergii)

Autumn olive (Elaeagnus umbellata)

Privet species (Ligustrum vulgare, Ligustrum obtusifolium)

Porcelain berry (Ampelopsis brevipedunculata)

Mile-a-minute vine (Persicaria perfoliata)